JP7340532B2 - CPOX reactor control system and method - Google Patents

Description

Exemplary techniques described herein relate to solid oxide fuel cell (SOFC) systems, and specifically to forming an enclosure wall from a thermally conductive material to generate thermal energy by conduction in a desired manner. Structural features and methods for forming an enclosure that provides a heat conduction path designed to distribute heat. More specifically, the present disclosure relates to thermal energy management within SOFC systems by providing thermal conduction paths configured to improve operational performance, safety, and reliability.

Related Art Conventional solid oxide fuel cell (SOFC) systems are used to generate electrical energy by an electrochemical process that transfers thermal energy from exhaust gas to incoming air, typically utilizing a gas-to-gas heat exchanger. . Exemplary embodiments are disclosed in U.S. Pat. es and Two -Stage Tail Gas Combustors'', disclosed in US Pat. No. 8,197,976. A gas-to-gas heat exchanger transfers waste heat from the exhaust gas to the incoming cathode air, while the overall system operates with hot spots in the tail gas combustion chamber and other locations where fuel is being combusted.

In conventional SOFC systems, the temperature surrounding the hot spot tends to exceed safe operating temperatures for many highly thermally conductive metals such as copper and aluminum. Additionally, highly thermally conductive metals such as copper and aluminum are often damaged by oxidation when exposed to the oxygen-rich cathode gases used in conventional SOFC systems. This has led the art to shy away from using high thermal conductivity metals with traditional SOFC systems, and instead configure them with temperature-resistant metals that surround hot spots to prevent burn-through and metal oxidation caused products. Avoiding other obstacles including reduced lifespan. Temperature resistant metals typically tend to include elevated temperature resident superalloys, including nickel and cobalt, such as Hastelloy, Monel, Inconel, and others that are less susceptible to damage by prolonged elevated temperatures and oxygen exposure. One problem with using elevated temperature resistant superalloys is that they have low thermal conductivity coefficients, such as less than about 40 W/m°K, more commonly less than 20 W/m°K. Compared to more thermally conductive metals (e.g. aluminum and copper alloys) with thermal conductivity coefficients greater than 200 W/m°K, temperature rise resistant superalloys are less suitable as thermal conductors. As a result, conductive heat transfer in conventional SOFC enclosures is slow, and the slow rate of heat transfer tends to create persistent hot spots or temperature gradients in the overall structure of the SOFC system.

More recently, SOFC systems have been constructed to promote thermal energy transfer by conduction to reduce temperature gradients. One such system is US Patent Application No. 14/399,795, entitled "SOFC-Conduction," published April 7, 2016 as US20160099476A1. Herein, the inner surface is formed as a thermally conductive path made from more thermally conductive metals, such as aluminum and copper alloys, to improve thermal conductivity from the hot spots of the structure to the cooling zone. and an outer metal enclosure. By providing a heat conduction path with a higher thermal conductivity coefficient and providing walls with greater thermal mass than others, each different enclosure wall system is designed to improve aluminum and copper enclosure walls, possibly including a copper core. This allows for more rapid heat conduction and tends to normalize quickly to a uniform temperature, thus reducing temperature gradients.

Conventional SOFC systems utilize internal temperature sensors to measure instantaneous temperatures at hot spot locations located inside the hot zone of the SOFC system. The motorized controller monitors the instantaneous temperature reported by each internal temperature sensor. If an overtemperature condition is detected, the electronic controller is operable to stop operation of the SOFC system by closing the inlet fuel valve. However, one problem with the use of internal sensors in elevated temperature environments is that thermal sensors may not be able to provide instantaneous internal temperatures at all, or may provide inaccurate instantaneous temperatures. Damage or inaccuracy of the internal thermal sensor can result in over-temperature conditions not being detected and causing catastrophic events such as burn-through of one of the enclosure walls. Other consequences include damage to the insulation around the hot zone and damage to the coating layers applied to the inner and outer enclosure walls. Even if damage from overtemperature conditions is minimal, replacement is required if the internal temperature sensor fails. Replacing a damaged internal temperature sensor requires disassembly of the SOFC system, which is costly.

In view of the foregoing considerations, there is a need in the art to provide a SOFC system that uses external temperature sensors to detect overtemperature operation conduction that can lead to system damage or failure without relying on internal sensors. There is. There is a further need in the art to provide passive backup for thermal sensors that detect overtemperature conditions. A passive buck is provided to shut down the SOFC system if the temperature sensor fails or otherwise reports an inaccurate temperature.

The present disclosure solves problems related to the control of solid oxide fuel cell systems and the control of catalytic partial oxidation (CPOX) fuel reformers that operate to reform mixtures of hydrocarbon fuels and oxidizers, such as air. Syngas reformate is delivered to the anode side of a plurality of solid oxide fuel cells (SOFCs) that operate to generate electrical power. The CPOX reformer of the present disclosure provides a control system and control method for monitoring temperature changes and temperature changes for each CPOX reaction, or SOFC reaction changes, and for independently changing the hydrocarbon fuel input flow rate and oxidizing Contains a control element for independently varying the input flow rate of the agent.

The fuel reformer module of the present disclosure initiates a CPOX reaction to reform a hydrocarbon fuel oxidizer mixture into a syngas reformate. The fuel reformer module includes a catalyst body having an input end for receiving a hydrocarbon fuel oxidizer mixture therein and an output end for delivering syngas reformate therefrom. The catalytic body is formed from a solid non-porous ceramic substrate having a plurality of independent catalytic fuel passages extending between an input end and an output end of each fuel passage. The inner surface of each catalytic fuel passageway is coated with a catalytic layer containing a material selected to initiate the CPOX reaction. A heat transfer element comprising a material having a thermal conductivity coefficient of 50 W/m°K or more, preferably 100 W/m°K or more is thermally conductively coupled to the catalyst body over the contact surface area. The contact surface area may be the outer or inner surface of the catalyst body and preferably extends along the longitudinal axis of the catalyst body. The first thermal sensor is thermally conductively coupled to the thermally conductive element. The first thermal sensor generates a first temperature signal corresponding to a surface temperature of the thermally conductive element proximate any surface of the thermally conductive element to which the first thermal sensor is coupled.

The SOFC system of the present disclosure includes a fuel reformer module as described above and a fuel oxidizer control module configured to mix a hydrocarbon fuel oxidizer mixture in various proportions. A fuel oxidizer control module is disposed between the hydrocarbon fuel source, the oxidizer source, and the input end of the catalyst body. A hydrocarbon fuel flow modulator is disposed between the hydrocarbon fuel source and the input end. An oxidant flow modulator is disposed between the oxidant source and the input end. The electronic controller is operative to send independent command and control signals to each of the hydrocarbon fuel flow modulator and oxidizer flow modulator.

A SOFC system comprises a solid oxide fuel cell (SOFC) stack that includes a plurality of individual SOFC fuel cells, each comprising a solid oxide anode electrode layer. Syngas reformate output from the fuel reformer module is directed to flow over the solid oxide anode electrode layer to initiate and sustain the SOFC reaction. The hot zone enclosure includes a plurality of hot zone enclosure walls joined together to surround a hot zone cavity surrounding the SOFC stack. The hot zone enclosure walls are formed from a material having a thermal conductivity coefficient of 100 W/m°K or greater and are joined together to form a first continuous heat transfer path that includes all of the hot zone enclosure walls. . a second thermal sensor is thermally conductively coupled to a surface of the first thermal conduction path, and a second temperature signal corresponding to a temperature of the surface of the first thermal conduction path to which the second thermal sensor is coupled; generate.

A range of first set point temperature values is stored by the electronic controller. The first set point value range corresponds to a calibrated operating temperature range known to produce a syngas reformate having a desired syngas composition. In one example, the first set point temperature value corresponds to a syngas composition that has a low percentage of unreacted hydrocarbon fuel molecules. A range of second set point temperature values is stored by the electronic controller. The second set point value range corresponds to a known calibrated operating temperature range to produce desired performance characteristics of the SOFC stack. In one example, the second set point temperature value corresponds to a fuel-power efficiency rating.

The electronic controller operates the first control loop based on sampling the first thermal sensor signal value. The first control loop commands the oxidant flow modulator to increase or decrease the oxidant flow rate to maintain the sampled first temperature signal value within a first set point value. . The electronic controller operates a second control loop based on sampling the second thermal sensor signal value. A second control loop instructs the hydrocarbon fuel flow modulator to increase or decrease the flow rate of the hydrocarbon fuel to bring the sampled second temperature signal value within a second set point value. maintain.

A method for controlling a SOFC system included delivering a mixture of a hydrocarbon fuel and an oxidant to the input end of a catalyst body. A hydrocarbon fuel flow modulator is disposed between the hydrocarbon fuel source and the input end of the catalyst body. an oxidant flow modulator disposed between the oxidant supply source and the input end of the catalyst body; The electronic controller delivers first command and control signals to the oxidant flow modulator to adjust the flow rate of the oxidant. The electronic controller delivers a second command and control signal to the hydrocarbon fuel flow modulator to adjust the flow rate of the hydrocarbon fuel. An input manifold located between the catalyst body output end and the SOFC stack delivers syngas reformate output from the catalyst body to a solid oxide anode electrode of a solid oxide fuel cell (SOFC) stack. Start the SOFC reaction at the SOFC reaction temperature. The electronic controller samples the first temperature control signal generated by the first temperature sensor and also samples the second temperature control signal generated by the second temperature sensor. The electronic controller stores a first range of set point temperature values corresponding to a desired composition of syngas reformate output from the fuel reformer module and a first range of set point temperature values corresponding to desired performance characteristics of the SOFC stack. Stores the range of setpoint temperature values for 2. The electronic controller controls the sampling of the first temperature sensor signal value and the flow rate of the oxidant to the oxidant flow modulator to maintain the sampled first temperature signal value within a first set point value. A first control loop is operated based on the instruction to increase or decrease. The electronic controller is configured to sample the second temperature signal value to maintain the second thermal sensor signal value within a second set point value and to cause the hydrocarbon fuel flow modulator to A second control loop is operated based on the command to increase or decrease the flow of fuel.

The features of the present disclosure will be best understood from the detailed description of the subject technology and illustrative embodiments thereof, chosen for purposes of illustration and illustrated in the accompanying drawings.
1 shows a schematic diagram of a non-limiting example SOFC system in accordance with the present disclosure; FIG. 1 shows a schematic side cross-sectional view of a non-limiting example solid oxide fuel cell stack assembly in accordance with the present disclosure; FIG. 1 shows a schematic side cross-sectional view of a non-limiting example fuel reformer module in accordance with the present disclosure; FIG. 1 shows a schematic side cross-sectional view of a non-limiting example catalyst body embodiment of a SOFC system in accordance with the present disclosure; FIG. FIG. 2 is a schematic diagram illustrating the surface area of a reactor base wall available for absorbing thermal energy being radiated from catalytic fuel passages in accordance with the present disclosure. 1 shows a schematic top cross-sectional view of a non-limiting example cathode chamber in accordance with the present disclosure; FIG. 1 illustrates a bottom schematic cross-sectional view of a non-limiting example fuel reformer module in accordance with the present disclosure; FIG. 1 shows a schematic side cross-sectional view of a non-limiting example solid oxide fuel cell stack assembly in accordance with the present disclosure; FIG. 1 shows a schematic representation of a further non-limiting exemplary embodiment of a solid oxide fuel cell (SOFC) system including a fuel and air input system according to the present disclosure. 3 illustrates a first exemplary non-limiting heat transfer element embodiment in heat transfer contact with a catalyst body according to the present disclosure; FIG. 3 illustrates a second exemplary non-limiting heat transfer element embodiment in heat transfer contact with a catalyst body according to the present disclosure. 3 illustrates a third exemplary non-limiting heat transfer element embodiment in heat transfer contact with a catalyst body according to the present disclosure; FIG. FIG. 7 illustrates a fourth exemplary non-limiting thermally conductive element embodiment in thermally conductive contact with a catalyst body according to the present disclosure. Isometric view of a fifth exemplary non-limiting embodiment showing a cylindrical catalyst body formed with a central longitudinal passageway configured to receive a heat transfer element therein in accordance with the present disclosure A top view is shown. 1 is a cross-sectional view through the longitudinal axis of a cylindrical catalyst body formed with a central longitudinal passage, showing a solid cylindrical heat transfer element according to the present disclosure therein; FIG. a sixth exemplary embodiment formed as a solid non-porous ceramic foam material formed with interconnected open cells distributed throughout the solid ceramic foam structure in accordance with the present disclosure and in thermally conductive contact with a catalyst body; FIG. 6 shows an isometric top view of a non-limiting heat transfer element embodiment. The O:C ratio versus T_CPOX, % _CH4 and % _C2HX values are shown in a graphical representation. Figure 15A shows a data table listing the O:C ratio versus T_CPOX, % _CH4 , and % _C2Hx values plotted in Figure 15A.

4. Definitions The following definitions are used throughout unless otherwise indicated.

5. List of Item Numbers Unless otherwise indicated, the following item numbers are used throughout.

Solid Oxide Fuel Cell System Referring to FIG. 1, a schematic diagram of a first exemplary non-limiting embodiment of the present disclosure depicts a solid oxide fuel cell (SOFC) system (100). The system (100), in this embodiment, includes a hot zone (105) enclosed within a hot zone enclosure wall (115) that surrounds a cylindrical hot zone cavity (120). The hot zone enclosure wall (115) is further surrounded by a thermal insulation layer (130) which is further surrounded by an outer enclosure wall (132). The hot zone enclosure wall (115) and the outer enclosure wall (132) are each separate cylinders having respective side walls that mechanically interact with different pairs of opposing disc-shaped end walls, as further described below. Including shaped side walls.

A hot zone enclosure wall (115) surrounds the fuel cell stack (135). The fuel cell stack (135) includes at least one SOFC fuel cell, but preferably includes a plurality of SOFC fuel cells, each electrically interconnected in series or parallel with a DC power output module (140). A DC power output module receives power generated by the fuel cell stack and delivers output power to an external power load (not shown). Each fuel cell includes a solid oxide cathode electrode (155) oriented to expose the cathode gas present within the hot zone cavity (120). The hot zone cavity (120) is filled with a cathode gas containing at least oxygen, e.g. chemically reacts with Each fuel cell further includes a solid oxide anode oriented such that it is not exposed to the hot zone cavity (120) or the cathode gas contained therein, but instead is exposed to an anode gas (reformed fuel) (125). An electrode (150) is provided so that during operation an anode gas passes over the solid oxide anode electrode (150) to chemically react with the solid oxide anode electrode (150). The SOFC fuel cell further includes a solid electrolyte layer (145) disposed to separate the solid oxide cathode electrode (155) from the solid oxide anode electrode (150). The solid electrolyte layer (145) is an oxygen ion conducting layer that serves as an ion exchange medium for ion exchange between the solid oxide anode electrode (150) and the solid oxide cathode electrode (155).

The fuel cell stack (135) is maintained at a high operating temperature (eg, in the range of 350-1200° C.) depending on the composition of the solid material layers of the fuel cell stack and the properties of the anode and cathode gases. Select a preferred operating temperature to support efficient electrochemical energy generation. By reacting hydrogen-containing anode gas (125) with solid oxide anode electrode (150) and reacting oxygen-containing cathode gas (126) with solid oxide cathode electrode (155), fuel cell stack (135) Electrical energy is generated.

The hot zone (105) contains spent anode gas (125a) after each of the spent anode gas and spent cathode gas has reacted with the corresponding solid oxide anode electrode (150) and solid oxide cathode electrode (155). and a combustion chamber configured to receive spent cathode gas (126a). Once mixed within the combustor module (180), spent anode gas (125a) and spent cathode gas (126a) are combusted. Thermal energy generated by the combustion occurring within the combustion module (180) is used to heat the hot zone enclosure wall (115) as well as the hot zone cavity (120).

The hot zone cavity (120) further surrounds the recuperator module (175). Recuperator module (175) is in fluid communication with combustor module (180) and receives combustion exhaust gases (127) exiting therefrom. The flue gas (127) passes through the recuperator module (175) as the flue gas (127) and incoming air (170) pass through separate gas conduits in a gas counterflow heat exchanger (not shown). and transfer thermal energy therefrom to the incoming air (170). The spent combustion exhaust gas (127a) then exits the recuperator module (175) and is delivered from the hot zone via the exhaust port (185). Incoming air (170) after exiting the recuperator module (175) includes cathode gas (126) that is delivered to the hot zone cavity (120).

The cold zone (110) of the system includes a fuel input module (197). Various hydrocarbon fuels, such as propane, methane, or kerosene, as well as other suitable fuels, are received by the fuel input module (197) from various fuel sources (not shown). The fuel input module (197) operates to condition the incoming fuel (160) delivered from the fuel source and deliver a desired volume or volumetric flow rate of incoming fuel (160) to the fuel reformer module (165). It is possible. The fuel reformer (165) is operable to reform the incoming fuel in a suitable manner by a desired chemical reaction with the solid oxide anode electrode (150).

The incoming fuel (160) includes liquid or gaseous hydrocarbon compounds from which hydrogen can be extracted. The incoming fuel (160) may be mixed with air, atomized, or otherwise vaporized. The fuel reformer module (165) of the present disclosure comprises a catalytic partial oxidation (CPOX) nuclear reactor that provides a catalyst support structure (167) having some of its surfaces covered by a catalyst layer, as described below. . As the incoming fuel passes over the catalyst layer, the fuel is combusted or partially combusted within the catalyst support structure (167). The heat generated by combustion reforms the incoming fuel (160) into hydrogen gas (H.sub.2) and carbon monoxide gas (CO). The reformed fuel exits the fuel reformer module (165) as an anode gas (125) that reacts with the solid oxide anode electrode (150) of each fuel cell in the SOFC fuel cell stack (135).

The cold zone (110) of the system includes an air input module (198) for inlet air (170) or another oxygen-rich source gas to the recuperator module (175). Air or any other oxygen-rich source gas may be received into the air input module (198) from various air sources (not shown), or air may be pumped by a fan to the recuperator module (175). Including indoor air. Air input module (198) is operable to regulate air flow to recuperator module (175). Recuperator module (175) heats incoming air (170) with flue gas (127) by passing the flue gas through a gas counterflow heat exchanger (not shown). The heated air exits the recuperator as cathode gas (126).

The cold zone (110) of the system includes an electronic controller (190) in electrical communication with a fuel input module (197) and an air input module (198). The electronic controller (190) includes a digital data processor and associated digital data memory having various operating programs and/or digital logic control elements operating thereon to manage the operation of the SOFC system (100). include. An electronic controller (190) is in electrical communication with the DC power output module (140) to monitor and regulate DC power output to the load. The electronic controller is also in electronic communication with a fuel input module (197) to monitor and regulate incoming fuel (160) and with an air input module (198) to monitor and regulate incoming air (170). The hot zone enclosure wall (115), the outer enclosure wall (132), and the fuel reformer as may be required to electronically communicate and further monitor the temperature of various surfaces of the SOFC system (100). It is in electronic communication with at least one temperature sensor (157) to monitor the temperature of one or more surfaces of the module (165) and other surfaces.

Each of the fuel input module (197) and air input module (198) includes a gas pressure sensor, such as one or more gas pressure regulators, gas flow actuator valves, mass or volumetric gas flow controllers, and/or volumetric flow sensors. temperature sensors, etc., each operable by, or in electrical communication with, an electronic controller (190) to control the input fuel (160) to the fuel reformer module (165) or the recuperator module (165). 175) may be regulated. More specifically, the fuel input module (197) in cooperation with the electronic controller (190) regulates the input fuel pressure and variably adjusts the incoming fuel mass or volumetric flow rate, as appropriate. Operable to stop incoming fuel (160) from entering the SOFC system (100). Similarly, the air input module (198) in cooperation with the electronic controller (190) also adjusts the input air pressure and variably adjusts the incoming air volume or volumetric flow rate, as needed. ) from entering the SOFC system (100). In some operating environments, air input module (198) may comprise a simple fan operating at a constant angular velocity without any additional air input control sensors or elements.

According to the present disclosure, the fuel reformer module (165) includes a surface of a ceramic catalyst support structure (167) to reform the fuel into hydrogen gas (H.sub.2) and carbon monoxide (CO). It is configured to cause an exothermic reaction between the inflowing fuel (160) provided above and the catalyst layer. Further, in accordance with the present disclosure, the improved fuel reformer module (165) includes a ceramic catalyst support structure (167) that includes a plurality of longitudinal fuel flow passages, each longitudinal fuel flow passage described below. The channel is coated with a catalyst layer on its inner surface. In addition, the fuel reformer module (165) directs thermal energy generated by exothermic reactions occurring within the ceramic catalyst support structure (167) along a longitudinal path toward the incoming fuel. The ceramic catalyst carrier structure (167) is configured to partially prevent auto-ignition of raw fuel entering the ceramic catalyst carrier structure (167) by providing a longitudinal fuel flow path as a means for communicating from the ceramic catalyst carrier structure (167). As seen in FIG. 1, the fuel reformer module (165) is disposed partially between the outer enclosure walls (132) and partially disposed outside the outer enclosure walls (132). and further configured to provide a heat conduction path through the outer enclosure wall (132). Additionally, the SOFC system (100) optionally includes one or more cooling devices ( (e.g., air fans, water pumps, etc.).

SOFC system (100) may optionally include a cold start module (195). The cold start module (195) is configured to receive and combust a portion of the incoming fuel (160) that is redirected to the cold start module (195). Operation of the cold start module (195) begins when the temperature of the incoming fuel (160) or the temperature of the hot zone enclosure wall (115) or the temperature of the fuel cell stack (135) is below the desired operating or reaction temperature. Initiated by the controller (190). During operation, a portion of the incoming fuel (160) is routed to a combustion chamber associated with the cold start module (195). A controllable fuel igniter is provided inside the combustion chamber of the cold start module (195), and the fuel inside the combustion chamber is connected to the incoming fuel (160), the fuel reformer module (165), and the hot fuel reformer module (165) during a cold start. It is ignited and combusted to heat the zone enclosure wall (115). Once the SOFC system (100) reaches the desired operating temperature, operation of the cold start module (195) is terminated.

In operation, the electronic controller (190) includes one or more cooling fans associated with the fuel input module (197), the air input module (198), the power output detector, etc., one or more electrically operated It is in communication with electronic elements such as possible gas flow actuator valves, gas flow detectors, and/or gas modulators, as well as other elements that may be needed to control various operating parameters of the SOFC (100). The electronic controller (190) monitors the DC current/power output as well as the temperature measured, such as by one or more thermocouples, and controls the incoming fuel and optionally the incoming fuel as a means of increasing or decreasing the DC current/power output. It is further operated to vary the volumetric flow rate of air.

8.2 Solid Oxide Fuel Cell Stack Side Section Referring now to FIG. 2, a second non-limiting exemplary embodiment of an improved SOFC fuel cell stack assembly (2000) according to the present disclosure is shown in a side cross-sectional view. It is shown. The SOFC fuel cell stack assembly (2000) includes a plurality of tubular fuel cells (2080) each extending longitudinally along a substantially cylindrical hot zone cavity or cathode chamber (2010). 2005).

Referring now to FIG. 2, a second non-limiting exemplary embodiment of an improved SOFC fuel cell stack assembly (2000) according to the present disclosure is shown in a side cross-sectional view. The SOFC fuel cell stack assembly (2000) includes a plurality of tubular fuel cells (2080) each extending longitudinally along a substantially cylindrical hot zone cavity or cathode chamber (2010). 2005).

In the exemplary embodiment, the disk-shaped bottom end wall (2016) also forms the bottom wall of the recuperator chamber (2210). As mentioned above, a recuperator chamber (2210) is provided to heat the incoming air (2200) that enters the fuel cell stack assembly via the cathode supply pipe (2145). Incoming air (2200), or cathode gas, enters the recuperator chamber (2210) via the recuperator input port (2230) and the cathode supply pipe (2145) via the recuperator output port (2235). Flows from the recuperator chamber (2010) back to the recuperator chamber (2010). One or more of the recuperator input port (2230) and recuperator output port (2235) may be disposed about the cathode supply tube (2145). The flow barrier (2212) directs the flow of air toward the peripheral wall of the recuperator chamber (2210), thereby increasing thermal energy exchange between the air passing through the recuperator chamber and its peripheral wall. The recuperator chamber (2210) is surrounded on its upper side by a disc-shaped separating wall (2214) disposed between the combustion chamber (2135) and the recuperator chamber (2210). The disk-shaped separator (2214) is configured to absorb thermal energy as a spent anode, the spent cathode gas is combusted in the combustion chamber (2135), and the absorbed thermal energy is transferred to the recuperator chamber (2210). ) becomes re-released internally.

An intermediate cylindrical enclosure surrounds the hot zone enclosure wall. The intermediate cylindrical enclosure is defined by an open ended longitudinal intermediate cylindrical side wall (2510) that mechanically interacts with a disc-shaped intermediate bottom end wall (2511) and an opposing disc-shaped intermediate top end wall (2513). surrounded. The intermediate cylindrical enclosure is sized to form a void (2155) substantially surrounding the longitudinal cylindrical sidewall (2015) and the disc-shaped top wall (2017). A void (2155) provides a fluid flow passageway proximate a portion of the hot zone enclosure wall, the fluid passageway being in fluid communication with a system outlet port (2165). The air gap (2155) is in further fluid communication with the combustion chamber (2135) through one or more combustor outlet ports (2150), and is in fluid communication with one or more cold start combustion chambers (2300) and one or more cold start outlet ports (2150). 2302). Thus, exhaust gases exiting each of the combustion chamber (2135) and cold start combustion chamber (2300) are routed through the hot zone enclosure wall before exiting the fuel cell stack assembly (2000) through the system exit port (2165). Flows over the outer surface. In one non-limiting exemplary embodiment, the dimension of the air gap (2155) from the outer surface of wall (2015) to the inner surface of wall (2510) ranges from 1 to 4 mm. The intermediate cylindrical enclosure also surrounds a cold start combustion chamber (2300), which is further described below.

Each of the intermediate enclosure walls (2510, 2511, and 2513) is a cobalt-nickel chromium-tungsten alloy that combines excellent high temperature strength up to 2000°F (1095°C) with very good resistance to oxidizing environments. Including a certain Hastelloy. Other metal alloys are also suitable, including Monel, a group of alloys containing about 30% copper, with up to 67% metallic nickel and small amounts of iron, manganese, carbon, and silicon. In any event, the intermediate enclosure walls (2510, 2511, and 2513) are preferably formed from a metal alloy having a thermal conductivity coefficient of less than about 25.0 W/m°K at the operating temperature of the hot zone. This much lower thermal conductivity of the intermediate enclosure wall compared to the thermal conductivity of the hot zone enclosure wall makes it possible, for example, to Compared to the much higher heat flow, the conductive heat flow from one area of the intermediate enclosure wall to another is much slower. Accordingly, in accordance with one aspect of the present disclosure, intermediate enclosure walls (2510, 2511, and 2513) are formed as a second heat transfer path with a slower heat transfer rate. In one other embodiment, the intermediate surrounding walls (2510, 2511, and 2513) are made of steel or other material that can have a thermal conductivity coefficient of less than about 50.0 W/m°K without departing from this disclosure. May include metal alloys.

An outer cylindrical enclosure surrounds the intermediate cylindrical enclosure. The outer enclosure is surrounded by an open-ended outer cylindrical sidewall (2514) that mechanically interacts with a disc-shaped outer bottom wall (2518) and an opposing disc-shaped outer top wall (2516). Each of the walls (2514, 2518, and 2516) is preferably made of aluminum having a thermal conductivity coefficient of greater than 140 W/m°K to provide a substantially uniform temperature of the outer cylindrical enclosure during operation. or contain aluminum alloys to assist in rapid thermal energy transfer. A thermal insulation layer (2512) is disposed between the outer surface of the intermediate enclosure wall and the inner surface of the outer enclosure wall, and the thermal insulation layer (2512) absorbs thermal energy radiated across the air gap (2155), or SOFC. Thermal energy carried through the air gap by exhaust gases exiting the system is inhibited from reaching the surfaces of the outer cylindrical sidewall (2514) and the disc-shaped outer bottom wall (2518). Preferably, the insulation layer (2512) is configured to ensure that the surfaces of the outer cylindrical sidewall (2514) and the disc-shaped outer bottom wall (2518) remain within operating parameters, e.g. The temperature of the outer cylindrical side wall (2514) and the disc-shaped outer bottom wall (2518) is configured to not reach above about 110°C. Accordingly, in accordance with one aspect of the present disclosure, outer enclosure walls (2514, 2518, and 2516) are formed as a third heat transfer path.

A plurality of tubular fuel cells (2080), also known as fuel rods or rods, are located inside the cathode chamber (2010) between a disc-shaped tube top support wall (2082) and an opposing disc-shaped tube bottom support wall (2084). supported longitudinally. Each tubular fuel cell (2080) includes a solid oxide anode electrode support structure that forms the inner diameter of the tube. A solid ceramic electrolyte layer is formed on the outer diameter of the solid oxide anode electrode support layer, and a solid oxide cathode electrode layer is formed on the outer diameter of the solid electrolyte layer. Each tubular fuel cell (2080) is open at both ends and provides a cylindrical fluid conduit through which anode gas, also referred to herein as reformate or syngas, flows. A plurality of tube retaining flanges (2086) are optionally provided to support the tube ends against the tube top support wall (2082) and the bottom tubular support wall (2084). Each tube retaining flange (2086) also includes a conductive terminal that electrically interacts with the DC power output module (140).

The solid anode electrode used to form the support layer of each tubular fuel cell (2080) may include a Celmet material such as nickel and doped zirconia, nickel and doped ceria, or copper and ceria. Alternatively, the solid anode electrode may include a perovskite such as Sr2Mg1-xMnxMoO6-δ or La0.75Sr0.25Cr0.5Mn0.5O3-δ. In either case, the inner surface of each tubular fuel cell (2080) includes a solid oxide anode electrode, and the anode gas flow (2115) passes through each disk-shaped tube top support wall (2082) so that the anode Only the gas stream (2115) enters each of the tubular fuel cells (2080) through the fuel inlet manifold (2055) and reacts with the solid anode electrode.

The solid oxide cathode electrode may include any one of lanthanum strontium cobalt oxide (LSC), lanthanum strontium cobalt iron oxide (LSCF), or lanthanum strontium manganite (LSM). A solid oxide cathode electrode forms the outer surface of each tubular fuel cell (2080). When the cathode chamber (2010) is filled with incoming air (2200) (i.e., cathode gas), the cathode gas reacts with the solid oxide cathode electrode formed on the outer surface of each tubular fuel cell (2080). .

An electrolyte layer is disposed between the anode layer and the cathode layer. Preferred electrolyte layers include an ionically conductive ceramic medium, preferably an oxygen ion conductor such as itrian-doped zirconia or gadolinium-doped ceria. Alternatively, the electrolyte layer is a proton conducting ceramic such as barium cerate or barium zirconate. Ideally, the electrolyte layer is formed with sufficient thickness to provide a near-hermetic barrier between the anode and cathode electrodes to prevent anode and cathode gases from passing through the electrolyte layer. be done.

The improved SOFC fuel cell stack assembly (2000) optionally includes a cold start combustion chamber (2300). The cold start combustion chamber (2300) is contained within the intermediate chamber wall and is surrounded by an intermediate longitudinal cylindrical side wall (2510), an intermediate top wall (2513), and a disk-shaped top wall of the cathode chamber (2017). The cold start combustion chamber (2300) forms an annular chamber volume that partially surrounds the fuel reformer module (2020). When starting up the SOFC system from a cold start, a portion of the incoming fuel air mixture (2025) is diverted into the cold start chamber (2300) via the fuel inlet (2304) and ignited by the igniter (2306). . Thus, during a cold start, a portion of the incoming fuel air mixture (2025) is combusted within the cold start combustion chamber (2300). Thermal energy generated by combustion within the cold start combustion chamber (2300) is transferred to its surrounding walls, including a disk-shaped top wall (2017) specially constructed with a copper core provided to rapidly absorb thermal energy. radiated. Additionally, the disk-shaped top wall (2017) is part of the hot zone enclosure wall surrounding the cathode chamber (2010) forming a first heat transfer path. Once absorbed by the disc-shaped top wall (2017), the thermal energy is rapidly conducted through the hot zone enclosure walls, all of which include highly thermally conductive materials. Exhaust from the combustion occurring within the cold start chamber (2300) exits the chamber through the exhaust port (2302) and passes through the air gap (2155) to the system exit port (2165). While passing through the air gap (2155), the combustion exhaust transfers thermal energy by radiation and convection to the hot zone enclosure walls (2015) and (2016) to bring the hot zone enclosure walls to the desired steady-state operating temperature. Further aids in heating.

The incoming fuel air mixture (2025) enters the modified SOFC fuel cell stack assembly (2000) via the fuel reformer module (2020). In this preferred embodiment, the fuel reformer is a catalytic partial oxidation (CPOX) nuclear reactor. A fuel reformer module (2020) receives an incoming fuel-air mixture (2025) through a fuel input conduit (2045) and reforms the incoming fuel-air mixture (2025) to fuel each of the tubular fuel cells (2080). A reformed fuel or syngas (2027) is provided that is used as an anode gas to react with the solid oxide anode electrode formed on the inner wall. Reformate fuel or syngas (2027) exits the fuel reformer module (2020) and enters the fuel inlet manifold (2055). The fuel inlet manifold (2055) is configured to distribute anode gas to the top or input end of each of the plurality of tubular fuel cells (2080). At the bottom or output end of each tubular fuel cell (2080), the spent fuel (2028) containing hydrogen deficient anode gas exits the tubular fuel cell into the combustion chamber (2135) and is replaced with spent cathode gas (2026) or oxygen It mixes with deficient air and burns.

Incoming air (2200), or cathode gas, shown in dotted lines, enters the improved SOFC fuel cell stack assembly (2000) via the cathode supply pipe (2145), where it enters the recuperator chamber (2000) where it is heated by its surface. 2210) and then re-enters the cathode supply pipe via the recuperator output port (2235). The heated air then passes through the combustion chamber (2135) while flowing through the cathode supply pipe (2145), and before entering the cathode chamber (2010), the air is further heated by the thermal energy generated by the combustion and passes through the cathode. is transmitted to the wall of the supply pipe (2145). A plurality of air outlet ports (2240) pass through the cathode supply tube (2145) and into the interior of the cathode chamber (2010), and heated air passes through the air outlet port (2240) and into the cathode chamber (2010). to go into. Once inside the cathode chamber, the heated air or cathode gas reacts with the solid oxide cathode electrode formed on the outer surface of each tubular fuel cell (2080). Spent cathode gas (2026) exits the cathode chamber via cathode chamber outlet port (2245) to combustion chamber (2135) where it is mixed with spent anode gas (2028) and combusted. Exhaust gas exits from the combustion chamber (2135) through the combustor exit port (2150) into the air gap (2155) and into the recuperator chamber (2210) as the exhaust gas flows toward the system exit port (2165). Heating the walls.

Figure 2 is a schematic side view of an improved SOFC fuel cell stack assembly (2000) showing only two tubular fuel cells (2080) for ease of illustration. A cross-sectional view is shown. However, a preferred stack has fuel arranged within the cathode chamber (2005) in a manner that provides efficient use of space, promotes efficient gas flow patterns, and provides the desired output at the desired voltage. Includes more than two tubular fuel cells (2080) with cells.

Referring now to FIG. 5, the figure shows a schematic top cross-sectional view of a non-limiting example cathode chamber of an example improved SOFC stack (5000) of the present disclosure. The cathode chamber (5002) is surrounded by an open-ended longitudinal cylindrical sidewall, such as the longitudinal cylindrical sidewall (2015) shown in FIG. 2, defining a circumferential edge (5010). The inner light-blocking region (5015) represents the longitudinal intermediate cylindrical sidewall (2510) and void (2155) shown in FIG. The outer light-blocking region (5020) represents the thermal insulation layer (2512) and outer cylindrical sidewall (2514) shown in FIG.

A cathode supply tube (5025) is located in the center of the cathode chamber (5002) and directs cathode gas into the cathode chamber through a plurality of radially disposed air outlet ports, such as (2240) shown in FIG. Spread. A central longitudinal axis (5030) centers the cathode supply tube (5025) and the circumferential edge (5010).

The improved SOFC stack (5000) includes a solid oxide fuel cell structurally forming the inner diameter of each tubular fuel cell (5040) and having a solid oxide cathode electrode formed on the outer diameter of each tubular fuel cell (5040). The fuel cell includes a plurality of substantially congruent tubular fuel cells (5040) each including a physical anode electrode. The first plurality of tubular fuels are arranged in an inner circular pattern (5035), with the center of each of the first plurality of tubular fuels having a central longitudinal axis (5030) as indicated by the inner circular pattern (5035). ) at the same radial distance from The inner circular pattern (5035) may be a symmetrical circular pattern in which the inner tubular fuel cells are equally spaced around the inner circular pattern (5035), or the first plurality of tubular fuel cells may be arranged at an unequal angle. They may be positioned around an inner circular pattern (5035) with a distribution or angular separation.

The second plurality of tubular fuel cells has a center of each of the second plurality of tubular fuel cells at the same radial distance from the central longitudinal axis (5030), as indicated by the outer circular pattern (5045). , arranged in an outer circular pattern (5045). The outer circular pattern (5045) may be a symmetrical circular pattern in which the second plurality of fuel cells are equally spaced around the outer circular pattern (5045), or the second plurality of fuel cells may be angularly spaced. It may be positioned around an outer circular pattern (5045) with an unequal distribution of separation. In this exemplary embodiment, the total number of fuel cells is twenty-two (22). Other patterns of fuel cell distribution with other total numbers of fuel cells can be used without departing from this disclosure.

Improved CPOX Fuel Reformer Referring now to FIGS. 2-4, a fuel reformer system (3000) according to the present disclosure is shown in schematic side cross-sectional view in FIG. 3 and in section in FIGS. 4 and 4A. Shown in exploded side cross-sectional view. The fuel reformer system (3000) includes a fuel reformer module (3020) mounted above a fuel inlet manifold (3055). The fuel reformer module (3020) transfers an incoming fuel air mixture (3025), i.e., unformed fuel, to a cylindrical fuel chamber (3005) surrounded by an annular peripheral wall (3010) and a reactor shield base wall. (3015) and a fuel reactor body (3040) configured to be received by a fuel chamber cap (3017). In a preferred embodiment, the fuel chamber cap (3017) is welded to the annular sidewall (3010). The fuel reformer system (3000) further includes a cylindrical catalyst body (3030). Each of the fuel reactor body (3040) and cylindrical catalyst body (3030) is arranged such that the cylindrical catalyst body (3030) is located directly above the fuel inlet manifold (3055), and the fuel furnace body (3040) is located directly above the cylindrical catalyst body (3055). installed in a cylindrical catalyst cavity (3035) located directly above (3030). The fuel reactor body (3040) and cylindrical catalyst body (3030) are each configured to provide fluid communication between the cylindrical fuel chamber (3005) and the fuel inlet manifold (3055).

Preferred reactor body materials have a thermal conductivity coefficient greater than 100 W/m°K and sufficient heat to rapidly transfer thermal energy from the interface between the fuel reactor body (3040) and the catalyst body (3030). Having mass or material volume. Preferred catalyst materials include ceramic substrates configured to provide reliable operation in the elevated temperature and chemically harsh environments of the CPOX reaction. Typically, the ceramic material has a thermal conductivity coefficient of less than about 40 W/m°K, but often less than about 10 W/m°K, which facilitates the conduction of heat from one region of the catalyst body to another. Reduce rate.

In this non-limiting exemplary embodiment, the cylindrical catalyst cavity (3035) is an annular enclosure formed with a central longitudinal axis coaxial with the central longitudinal axis (2060), as shown in FIG. It has a side wall formed by the inner diameter of the body wall (3060). The cylindrical catalyst cavities (3035) each have one circular opening passing through the disk-shaped outer top wall (2516) of the outer enclosure and the other circular opening passing through the disk-shaped top wall (2017) of the hot zone enclosure. and two open ends forming a circular opening.

In a preferred embodiment, the annular enclosure wall (3060) has a higher thermal conductivity than the fuel furnace body (3040) to prevent heat transfer between the annular enclosure wall (3060) and the fuel furnace body (3040). formed to be low. In a preferred embodiment, the annular enclosure walls (3060) each have a high nickel content to resist oxidative damage, and each have a suitable service temperature rating, e.g., greater than 400°C, and each has a thermal conductivity coefficient of less than about 25.0 W/m°K. Additionally, the annular enclosure wall (3060) is a thin wall, eg, 0.02 to 0.1 inches thick, to provide further heat transfer therethrough.

An annular enclosure wall (3060) is thermally conductively connected to a disk-shaped top wall (2017) at its lower open end that is part of the hot zone enclosure wall defined above as the first heat transfer path. be done. The annular enclosure wall is thermally conductively connected to the disc-shaped outer top wall (2516) at the upper open end, which is a portion of the outer enclosure wall defined above as the third heat transfer path. The annular enclosure wall (3060) is thermally conductively connected to an intermediate top wall (2513) between its top and bottom open ends, the intermediate top wall described above as a second heat transfer path. This is part of the intermediate enclosure wall. Thus, according to one aspect of the present disclosure, the annular enclosure wall (3060) is thermally conductively connected to each of the first heat transfer path, the second heat transfer path, and the third heat transfer path. It is formed as a fourth heat conduction path.

A catalyst support flange (3065) extends from or is formed by the disk-shaped top wall (2017). The catalyst support flange (3065) is sized to define a diameter of the circular opening (3070) that is small enough to prevent the cylindrical catalyst body (3030) from passing through the circular opening (3070). . A first annular washer (3075) is disposed between the catalyst support flange (3065) and the bottom surface of the cylindrical catalyst body (3030). The first annular washer (3075) provides a gas seal between the cylindrical catalyst cavity (3035) and the cylindrical catalyst cavity (3035) when longitudinal downward pressure is applied to the cylindrical catalyst body (3030). In addition, the first annular washer (3075) is configured as an insulator that thermally isolates the catalyst support flange (3065) from the disc-shaped top wall (2017). Preferably, the first annular washer (3075) comprises alumina formed of sufficient thickness and with a suitable outer diameter dimension to provide the desired gas sealing and insulation properties. More generally, the first annular washer (3075) preferably comprises a non-porous material of very low thermal conductivity, for example a thermal conductivity coefficient of less than 40 W/m°K, including most ceramic materials. has.

The diameter of the cylindrical catalyst cavity (3035) is sized to receive an annular insulation element (3080) within the cylindrical catalyst cavity (3035) surrounding the cylindrical catalyst body (3030). An annular insulation element (3080) is provided to thermally isolate the cylindrical catalyst body (3030) from the annular enclosure wall (3060). In addition, the annular insulating element (3080) is configured to accurately center the cylindrical catalyst body (3030) with respect to the central longitudinal axis of the cylindrical catalyst cavity (3035), and further (3040) may be configured to angularly orient the cylindrical catalyst body (3030) for precise angular alignment with one or more features of (3040). Both the first annular washer (3075) and the annular insulating element (3080) are removed from the enclosure wall, e.g. the annular enclosure wall (3060) and the top wall (2017), preferably at a higher temperature than the cylindrical catalyst body. It is provided to prevent heat conduction to the operating catalyst body (3030).

The cylindrical catalyst body (3030) is a solid non-porous ceramic substrate formed to include a plurality of longitudinally disposed catalytic fuel passages (3085) each passing completely through the cylindrical catalyst body (3030). Equipped with. Each catalytic fuel passage (3085) provides an individual fuel conduit extending longitudinally through the cylindrical catalyst body (3030). Thus, each catalytic fuel passage provides fluid communication between a cylindrical catalyst cavity (3035) and a fuel inlet manifold (3055). Additionally, the inner surface of each of the catalytic fuel passages (3085) is formed with a catalytic layer (3090) coated thereon. The catalytic layer (3090) includes catalytic material that can be used to reform the incoming fuel-air mixture (3025) by catalytic partial oxidation, which is an exothermic reaction that causes partial combustion of the fuel-air mixture (3025). In this non-limiting exemplary embodiment, the preferred catalyst layer (3090) comprises a metallic or oxidized phase of rhodium (Rh). Other suitable catalysts that can be used in the catalyst layer (3090) include Pt, Pd, Cu, Ni, Ru, and Ce. The solid non-porous ceramic substrate used to form the cylindrical catalyst body (3030) is preferably made of alumina, which has a relatively low thermal conductivity coefficient compared to that of the fuel reactor body (3040). or any other non-porous material. In this non-limiting embodiment where a ceramic substrate is used, the thermal conductivity coefficient of the catalyst body is less than 40 W/m°K.

As described further below, an incoming fuel air mixture (3025) enters the cylindrical fuel chamber (3005), passes through the reactor shield base wall (3015), and enters each of the catalytic fuel passages (3085); There it reacts with the catalyst layer (3090) and then enters the fuel inlet manifold (3055) which is distributed in each of the tubular fuel cells (2080).

Fuel Reactor Body Referring now to FIGS. 2, 3, 4, and 4A, a fuel reactor body (3040) is disposed partially within a cylindrical catalyst cavity (3035) with a disk-shaped outer top wall. (2516) and partially into the cold zone so that at least a portion of the fuel reactor body (3040) is exposed to ambient air. An annular peripheral wall (3010) provides a cylindrical side wall of a cylindrical fuel chamber (3005). A fuel input conduit (2025) passes through the annular peripheral wall (3010) and delivers an incoming air-fuel mixture (2025/3025) to the cylindrical fuel chamber (3005). As will be appreciated, other geometric shapes can be used to form the annular peripheral wall (3010) and fuel chamber (3005), which can have rectangular, rectangular or other cross-sections in their cross-section. be.

The reactor shield base wall (3015) comprises a circular bottom wall of a cylindrical fuel chamber (3005), preferably formed with an integrally annular peripheral wall (3010). However, the reactor shield base wall (3015) and the annular peripheral wall can be formed as separate parts and joined together, for example, by welding, soldering, mechanical fasteners, and other suitable joining techniques. A plurality of base wall fuel passages (3095) each completely extend the reactor shield base wall (3015) along a longitudinal axis, e.g., with each base wall fuel passage parallel to the central longitudinal axis (2060). pass through. Each base wall fuel passageway (3095) provides a fuel conduit that extends longitudinally through the reactor shield base wall (3015). Additionally, each base wall fuel passageway (3095) is longitudinally aligned with and in fluid communication with a corresponding one of a plurality of catalytic fuel passageways (3085) passing through the cylindrical catalyst body (3030).

As shown in FIGS. 4 and 4A, the interface (3032) is defined by the bottom outer surface of the reactor shield base wall (3015) and the top or input surface of the cylindrical catalyst body (3030). In a non-limiting exemplary embodiment, one or the other or both of the two surfaces forming the interface (3032) includes raised features (3033). The raised feature extends from the bottom surface of the reactor shield base wall (3015) at a location where the raised feature contacts the opposing surfaces at the interface (3032) to provide a small gap between the two opposing surfaces. It may include a circular ring or rings, preferably three discreet raised protrusions, formed at one or more locations. More generally, the interface (3032) is formed with a gap between the bottom surface of the reactor shield base wall (3115) and the top surface of the cylindrical catalyst body (3030). All gaps allow radioactive thermal energy emanating from each of the catalytic fuel passages to impinge on the bottom surface of the reactor shield base wall (3015), such that substantially all of the bottom surface of the reactor shield base wall (3015) is , is provided to make available for absorbing thermal radiation impinging upon it.

At the interface (3032), each base wall fuel passage (3095) is aligned with its corresponding catalytic fuel passage (3085) along a substantially coaxial longitudinal axis. In this configuration, the fuel-air mixture (2025) delivered to the cylindrical fuel chamber (3005) passes from the cylindrical fuel chamber (3005) through each of the plurality of base wall fuel passages (3095) and the interface ( 3032) and enters each of the corresponding catalytic fuel passages (3085). Once inside the catalytic fuel passageway (3085), the fuel-air mixture begins to react with the catalyst-coated sidewall surface (3090) to convert the fuel-air mixture into reformate or syngas. Begin the catalyzed partial oxidation reaction used. According to one aspect of the present disclosure, the thermal energy generated by the CPOX reaction occurring inside the catalytic fuel passageway (3085) is radiated onto the bottom surface of the reactor shield base wall (3115) to be partially absorbed thereby. be done. In addition, the thermal energy generated by the CPOX reaction occurring within the catalytic fuel passageway (3085) is thereby radiated onto the inner surface of the base wall fuel passageway (3095) for partial absorption.

The fuel reactor body (3040) is formed from a material that has a relatively high thermal conductivity compared to that of the ceramic material used to form the cylindrical catalyst body (3030). Preferred reactor body materials have thermal conductivity coefficients greater than 100 W/m°K. Accordingly, in one non-limiting exemplary embodiment, the entire fuel reactor body (3040) is constructed from a piece of copper or a copper alloy, a piece of beryllium or a beryllium alloy, a piece of aluminum or an aluminum alloy, Formed from a unit piece of brass or a brass alloy, from a unit piece of tungsten or a tungsten alloy, the alloy may include molybdenum, nickel, chromium, brass, tungsten, etc. In this example, unit means that the entire fuel reactor body (3040) is formed from a single piece of metal, for example cast or machined. In alternative embodiments, the fuel reactor body (3040) can be formed from multiple cast or machined elements assembled together, e.g., welded, brazed, etc. in a manner that provides a continuous heat transfer path. It can be attached or mechanically fixed. In either case, the desired material has a thermal conductivity coefficient of at least 100 W/m°K, with materials having a thermal conductivity of greater than 300 W/m°K being used. In addition, the wall thickness and/or thermal mass of the fuel reactor body (3040) may vary from a high temperature region of the reactor body (3040) proximate to the interface (3032) to a low temperature region of the reactor body (3040), e.g. promoting rapid heat transfer to regions located outside the hot zone and minimizing temperature gradients between the interface (3032) and elements of the reactor body located outside the hot zone; is sufficient. A further feature of the reactor body material is that it preferably has a service temperature of at least above 200°C, preferably up to 1000°C.

In this non-limiting exemplary embodiment, the fuel reactor body (3040) is formed from aluminum, preferably aluminum 6061 alloy, having a thermal conductivity coefficient of approximately 167 W/m°K. Aluminum and aluminum alloys are preferred because they spontaneously form a stable oxide layer that protects the bulk structure from corrosive oxidative damage and can be used without additional applied protective coatings. Additionally, aluminum and aluminum alloys can be anodized to prevent or reduce surface oxidation. In a preferred embodiment, the entire fuel reactor body (3040) includes solid elements including one of aluminum 6061 alloy; however, the fuel reactor body (3040) may be constructed using mechanical fasteners without departing from this disclosure. It may include assemblies formed by assembling a plurality of individual subassembly elements, welding or brazing, using interlocking mechanical features, or the like.

More specifically, in accordance with important aspects of the present disclosure, the relative thermal conductivity of each of the cylindrical catalyst body (3030), the annular enclosure wall (3060), and the fuel reactor body (3040) is ) to the heat dissipation flange (3100) disposed outside the hot zone and to promote absorption of thermal radiation impinging on the surface of the reactor shield base wall (2015). . This configures the fuel reactor body (3040) as the locally most thermally conductive element at the interface (3032), allowing the fuel reactor body (3040) to e.g. Either moved or passively cooled, for example, by configuring the surface to extend outside the hot zone by exposing the fuel reactor body (3040) to ambient air. Ru. Therefore, the configuration of the fuel reactor body (3040) provides a heat transfer path between the interface (3032) and the outside air and a cooler portion of the fuel reactor body provided by exposing a portion of the fuel reactor body to the outside air. Establishing and maintaining a temperature gradient between the interface (3032) and the ambient air outside the hot zone. The temperature gradient obtained between the part of the fuel reactor body exposed to the outside air and the part of the reactor body adjacent to the interface (3032) is from the interface (3032) to the part of the fuel reactor body exposed to the outside air. tends to promote substantially continuous thermal energy conduction through the fuel reactor body (3040).

The fuel reactor body (3040) includes a heat dissipation flange (3100), for example a disk-shaped flange extending radially from an annular peripheral wall (3010). A heat dissipating flange (3100) is supported externally of the outer enclosure on a disk-shaped outer top wall (2516) and is exposed to ambient air. Preferably, the heat dissipation flange (3100) is integrally formed with the annular peripheral wall (3010), but the heat dissipation flange (3100) is attached to the annular shape by welding, soldering, mechanical fasteners, or other attachment means. It may include a separate element attached to the perimeter wall (3010).

The annular seal plate (3105) is disposed between the disk-shaped outer upper end wall (2516) and the heat dissipation flange (3100), and is arranged between the upper surface of the disk-shaped outer upper end wall (2516) and the bottom surface of the heat dissipation flange (3100). provide a mechanical interface between them. Annular seal plate (3105) includes a central through hole sized to receive an annular peripheral wall (3010) therethrough. An O-ring sealing element (3110) or the like is disposed between the annular sealing plate (3105) and the heat dissipation flange (3100), for example in an O-ring groove, to gas-seal the upper part of the cylindrical catalyst cavity (3035). play a role. A second O-ring seal element (3115) may be provided between the top surface of the disc-shaped outer top wall (2516) and the bottom surface of the annular seal plate (3105).

Both the annular seal plate (3105) and the heat dissipation flange (3100) protect the reactor shield against the top surface of the cylindrical catalyst body (3030) at the interface (3032) or a raised surface (3033) formed thereon. The disc, such as by a fastener, is inserted in a manner that applies a downward force against the fuel reactor body (3040) to secure the bottom surface of the base wall (3015) and further compress the O-ring seal element (3110). Attached to the mold outer top wall (2516).

Referring now to FIG. 6, a schematic top cross-sectional view of the fuel reactor body (3040) shows a heat dissipation flange (3100) extending radially from the annular peripheral wall (3010). Fasteners (3120) extend through the heat dissipation flange (3100) and annular seal plate (3105) and attach the heat dissipation flange (3100) and annular seal plate (3105) to the disc-shaped outer top wall (2516). An annular peripheral wall (3010) extends radially outside the annular enclosure wall (3060) such that a seal plate (3105) seals the cylindrical catalyst cavity (3035). An array (3125) of base wall fuel passages (3095) is shown passing through the reactor shield base wall (3015).

Referring now to FIG. 3, the fuel reformer system (3000) may include external cooling and temperature sensing elements readable by an electronic controller (190). In one non-limiting exemplary embodiment, an air moving element (3130), such as a rotating fan blade attached to a rotating motor operable by an electronic controller (190), moves air over a heat dissipation flange (3100). 3100, thereby increasing convective thermal energy transfer from the flange (3100) to the surrounding atmosphere. Additionally, a temperature sensing element (3135) in contact with a surface of the heat dissipation flange (3100) or one or more other surfaces of the fuel reactor body (3040) communicates with the electronic controller (190) via a communication path (3140). ) can be used to deliver temperature signals to Operation of the air moving element (3130) may be constant or may be variably triggered by changes in the temperature signal emitted by the temperature sensing element (3135). In one non-limiting mode of operation, air movement element (3130) is activated when temperature sensing element (3135) reports a temperature above a desired high temperature limit, e.g., above 50°C, and temperature sensing element (3135) The air movement element (3130) is not activated when the air transfer element (3130) reports a temperature below the desired high temperature limit, for example below 45°C.

In addition, the temperature signal emitted by the temperature sensing element (3135) controls the flow of fuel to the cold start combustion chamber (2300) when the temperature of the heat dissipation flange (3100) reaches the desired steady state temperature range. It can be used to control operation of the cold start combustion chamber (2300) to shut down.

In one example mode of operation, electronic controller (190) receives a temperature signal from temperature sensing element (3135) via communication path (3140) and determines an instantaneous flange temperature based thereon. Electronic controller (190) then determines whether the flange temperature is within one or more desired temperature ranges and, if not, the instantaneous temperature indicated by temperature sensing element (3135) is within safe operating limits. actuates the air transfer element (3130) or controls the flow of fuel into the cold start combustion chamber (2300) by instructing the fuel delivery module (197) to close a gas flow actuator valve or the like when the Execute various commands such as starting or stopping flow or stopping fuel delivery to the fuel reformer system (3000). In one non-limiting mode of operation, electronic controller (190) is configured to activate air movement element (3130) when the temperature of heat dissipation flange (3100) exceeds 50°C. In other exemplary embodiments, the air movement element (3130) may have multiple modes of operation that can be used to move more or less air as needed based on different temperature thresholds.

Interface Configuration Referring now to FIG. 4, an exploded side cross-sectional view of the interface (3032) between a corresponding pair of base wall fuel passages (3095) and a catalytic fuel passage (3085) is shown in a corresponding pair of reactor shield Each of the base wall fuel passages (3095) and catalytic fuel passages (3085) are shown aligned along a common longitudinal axis. Thus, each corresponding pair of base wall fuel passages and catalytic fuel passages provides a vertical flow path for the fuel air mixture to pass from the cylindrical fuel chamber (3005) to the fuel inlet manifold (3055). As mentioned above, a gap may be provided between the mating surfaces of the interface (3032) to expose the surface of the reactor shield base wall (3015) to thermal radiation emitted by the CPOX reaction, but the present disclosure The gap is not shown in FIG. 4 for simplicity. As indicated by reference numeral (3090), a catalyst layer is formed on the sidewall of each catalytic fuel passageway (3090). As further shown in FIG. 4, the arrow pointing to FIG. 4A indicates that FIG. 4A is a schematic view of the interface (3032) as viewed from inside the catalytic fuel passageway (3085) toward its fuel input end. shows. In this non-limiting exemplary embodiment, the diameter (D) of each of the circular base wall fuel passages (3095) is 1.3 mm, and the thickness of the reactor shield base wall is 13 mm, so that each fuel passage (3095) is 13 mm long. In a preferred embodiment, the ratio between the longitudinal length of the fuel passage and its diameter is at least 5, preferably 10 and at most 20. The side wall dimension of each of the rectangular catalytic fuel passages (3085) is 1.3 mm, and the thickness of the cylindrical catalyst body (3030) is approximately 25.4 mm, so that each catalytic fuel passage (3085) is 25.4 mm long. It is. In a preferred embodiment, the ratio between the longitudinal length of the catalyst channel and its rectangular dimension is at least 10, preferably from 15 to 25, and at most 40.

The cylindrical catalyst body (3030) has a circular cross section with an array of catalytic fuel passages (3085) formed within the circular cross section over a circular area of 25.4 mm (1.0 inch) in diameter. Each of the catalytic fuel passages in the array has a rectangular cross section and extends completely through the cylindrical catalyst body (3030). In this non-limiting exemplary embodiment, each rectangular catalytic fuel passage has side dimensions of 1.3 mm and a length of 25.4 mm. Alternatively, the catalyst body (3030) and the array of fuel passages can have other non-circular cross-sections without departing from this disclosure.

The reactor shield base wall (3015) has circular base wall fuel passages (3095) formed in a 25.4 mm (1.0 inch) diameter circular array area opposite the circular array area of cylindrical catalyst bodies (3030). ) is formed with an array of In this non-limiting exemplary embodiment, each circular base wall fuel passageway (3095) has a diameter of 1.3 mm and a length of 13.0 mm. Alternatively, the reactor shield base wall (3015) and the array region formed thereon can have other non-circular cross-sections without departing from this disclosure. As mentioned above, each circular base wall fuel passage (3095) in the array of base wall fuel passages is coaxial with one of the rectangular catalytic fuel passages (3088) in the array of catalytic fuel passages, so that each base The central longitudinal axis of the wall fuel passageway (3095) is coaxial with the central longitudinal axis of the corresponding catalytic fuel passageway (3085).

Solid material of the reactor shield base wall (3015) surrounds each circular base wall fuel passage and solid material of the cylindrical catalyst body (3030) surrounds each rectangular catalytic fuel passage. In a non-limiting exemplary array pattern, all the passageways are arranged in multiple parallel linear arrays. Each linear array is offset from adjacent linear arrays by the same pitch dimension of 1.2 times the diameter of the circular passage. In this example, the pitch dimension is 1.56 mm. Based on this non-limiting exemplary array disposed on a 25.4 mm diameter circle, the total number or circular passageways (3095) within the circular array area is approximately 208.

The combined area of 208 passages, each with a diameter of 1.3 mm, is 276 mm ² . The total area of the array area with a diameter of 25.4 mm is 507 ^mm2 . The circular array is therefore such that the bottom surface of the reactor shield base wall (3015) provides a surface area of approximately 231 ^mm2 facing the interface (3032) available for absorbing the radiant thermal energy impinging upon it. The area of solid material within the area is approximately 231 mm ² . In this exemplary embodiment, the ratio of solid surface area to pore diameter area is 0.84. As a percentage of the total area of the circular array, about 54% of the total area is the circular passage area and about 46% of the total area is the solid material area. As will be understood by those skilled in the art, by decreasing the diameter of the circular base wall fuel passage, the surface area to hole diameter area ratio can be increased. Since the surface area at the interface (3032) is impinged by the radiant heat energy released by the CPOX reaction, increasing the solid surface area without changing the temperature will increase the absorption of thermal energy into the reactor shield base wall (3015). do. In a preferred embodiment, the ratio of solid surface area to pore diameter area ranges from 0.75 to 0.9.

As mentioned above, the radioactive thermal energy released by the CPOX reaction also enters the circular base wall fuel passageway (3095) and at least a portion of the radioactive thermal energy impinges on its interior surface. The angle of incidence of radiant thermal energy impinging on the inner surface of the circular base wall fuel passageway (3095) is approximately the grazing angle, but is long compared to the diameter of the passageway and the reflected energy, and if reflected at an incidence near the grazing angle However, as it traverses the fuel passageway, it eventually hits and reflects from the inner surface over many reflection cycles (3095). The total surface area of the inner surfaces of all 208 circular passages is approximately 11043 ^mm2 .

Referring now to FIG. 4A, the diagram shows the interface (3032) of a single circular fuel passageway (3095) and a single rectangular catalytic fuel passageway (3085) as viewed from the fuel inlet manifold (3055). As further shown, in accordance with the present disclosure, each base wall passage (3095) has a circular cross-section along its longitudinal length having a diameter (D), and each catalytic fuel passage (3085) has a circular cross-section along its longitudinal length. It has a rectangular cross section with a lateral dimension (S) along its entire length. In the non-limiting exemplary embodiment of FIG. 4A, the diameter (D) and side length (S) are equal, and the area filled with vertical lines (B) is the exposed bottom of the reactor shield base wall (3015). It is the surface area. A surface area (B) is located at the interface (3032) proximate to the input end of each catalytic fuel passageway (3085) and is specifically provided to absorb thermal radiation radiating from the catalytic surface (3090). Additionally, if a gap is provided between the opposing surfaces of the interface (3032), thermal radiation will partially enter the gap by reflection from the surface area (B).

Equation (1) below provides the area of surface area (B).
A _s −A _c =S ² −π(D/2) ² equivalent: 1

However, _As is the area of a rectangle (3085) having a side length (S).

A _C is the area of a circle (3095) with diameter (D).

When S=D, the surface area AB of the surface area (B) is as follows: (A _B )=S ² (1-π/4)=0.2146S ² equivalents: 2

In other words, the area of surface (B) is approximately 21% of the area of rectangle (3085). As will be appreciated, by increasing the area AB, e.g., increasing the corner dimension from (S) to (S1), or decreasing the diameter (D) of the circular passageway (3095), the catalytic fuel passageway The exposure of the surface (B) to internally generated thermal radiation can be increased. As the side dimension of the catalytic fuel passage increases from (S) to (S1), the area SB increases to 50% of the area of a rectangle of dimension (S1) when the S1/D ratio is equal to about 1.253. I can do it.

The surface area (B) is directly exposed to the CPOX reaction occurring inside the rectangular catalytic fuel passageway (3085) and is optimally positioned to absorb the thermal energy radiated from the catalytic fuel passageway. Even if there is no gap at the interface (3032), in a non-limiting exemplary embodiment of the present disclosure, the surface (B) as well as the inner surface of the base wall fuel passageway (3095) is connected to the cooler reactor shield base wall ( 3015) to absorb sufficient radiant thermal energy released by the CPOX reaction to prevent burn-through of the catalyst layer. However, as will be understood by those skilled in the art, when a gap is provided, additional radiant thermal energy enters the gap and impinges on the cooler solid material surface area of the reactor shield base wall (3015) over a number of cycles. can absorb additional thermal energy that is reflected and released by the CPOX reaction.

Thermal Energy Transfer Not wishing to be bound by theory, Applicants have proposed that when the fuel-air mixture (2025, 3025) is heated to a suitable reaction temperature, the catalyst layer (3090) is deposited in close proximity to the interface (3032). It is believed that upon contact with , an exothermic catalyzed partial oxidation reaction is immediately initiated. Additionally, Applicants believe that the exothermically catalyzed partial oxidation reaction reaches a maximum temperature near the interface (3032), with a maximum temperature of about 900-1000°C. In response to rapid heating proximate the interface (3032), the temperature of the fuel-air mixture entering the catalytic fuel passageway (3085) and the catalyst layer (3090) increases as thermal energy is transferred by the fuel-air mixture as well as to the catalyst layer (3090). It rises rapidly as it is absorbed by In response to the increase in temperature, the fuel-air mixture rapidly expands in volume to fill the catalytic fuel passageway (3085) and exits the catalytic fuel passageway to the cylindrical catalyst cavity (3035) and fuel inlet manifold (3055). Fill it. During gas expansion, more of the fuel-air mixture contacts the catalyst layer (3090) distal to the interface (3032) and contributes to an exothermic catalyzed partial oxidation reaction, thereby further heating and heating the fuel/air mixture. Expand. Therefore, most of the thermal energy generated by the catalyzed partial oxidation reaction is absorbed by the fuel/air mixture and transported from the catalytic fuel passageway to the fuel inlet manifold (2055). In one example mode of operation, the volume of fuel/air mixture delivered to the CPOX reactor would produce approximately 300 watts during the CPOX reaction.

A portion of the thermal energy generated by the catalyzed partial oxidation reaction is absorbed by the catalyst layer (3090). In this example, the catalyst layer is metal (for example Rh) and has a thermal conductivity coefficient of about 150 W/m°K. Thermal energy absorbed by the catalyst layer (3090) is therefore thermally conducted through the catalyst layer thickness to reach the ceramic catalyst body (3030) and along the longitudinal length of the catalyst layer (3090). However, since the catalyst body (3030) is a ceramic material with a thermal conductivity coefficient of about 45 W/m°K, the heat flux density (W/m ² ) entering the ceramic material is low and therefore the heat absorbed by the catalyst layer The energy is re-released into the catalytic fuel passageway instead of being thermally conducted into the ceramic material. However, the low heat flux density along the radial axis of the ceramic catalyst body means that thermal energy is conducted radially from the catalytic fuel passages such that the thermal energy is transferred to the fuel-air mixture inside the fuel passages; or b) radiates from the end of the fuel passage into either the above-mentioned fuel inlet manifold or surface area (B), or c) e.g. by entering a gap provided at the interface, the reactor shield base wall. d) radiated into the circular base wall fuel passage and transferred by convective heat transfer to the incoming gas-air mixture; or e) absorbed thereby. This result is desirable because it prevents radiation to the extent that it radiates onto the inner surface of the base wall fuel passageway (3095).

Therefore, the thermal energy absorbed by the catalyst layer is not easily dissipated into the ceramic catalyst body (3030). Instead, thermal energy is re-released into the catalytic fuel passages to further heat the fuel-air mixture. In addition, the thermal energy emitted or reflected by the catalyst layer impinges on other surfaces of the catalyst layer and is thereby partially absorbed and partially reflected. However, without at least one outlet for thermal radiation to exit the catalytic fuel passageway, the rate of energy absorption of the catalytic layer (3090) may exceed the rate of energy re-emission, thereby causing the temperature of the catalytic layer to It continues to increase until it burns out causing permanent damage to the fuel passages.

As mentioned above, Applicants believe that the total power generated by the CPOX reaction is 300W. Using the Stefan-Boltzmann equation, listed below as Equation 3, the total power that can be absorbed by the collective surface area (B) shown in FIG. 4A, i.e., based on the 208 base wall passages (3095), and temperature.

P=eσAS _f (Tc ⁴ −Tb ⁴ ) equivalent 3

However, P = net absorbed power (watts), e = surface emissivity, σ = 5.6703 x 10 ^-8 (W/m ² K ⁴ ) Stefan-Boltzmann constant, A = area where radiation is emitted (m ² ), Sf - view factor related to the angle of incidence at which the radiation impinges on the surface area A, T _c = temperature of the radiation source (°K), and T _b = temperature of the surface area A (°K).

What is particularly important is when Tc and Tb become equal. Equation 3 shows that the net radiated power absorbed by the reactor shield base wall (3015) is zero. Therefore, without the cooler surface area provided by the reactor shield base wall (3015), the surface temperature inside the catalytic fuel passages can continue to increase until the catalytic layer overheats and burns out.

In a non-limiting exemplary embodiment, each rectangular catalytic fuel passage (3085) has a side dimension (S) equal to 1.3 mm (0.0013 m), and each circular base wall passage (3095) has a lateral dimension (S) equal to 1.3 mm (0.0013 m); In a non-limiting embodiment with a diameter of .3 mm, the collective area of all surface areas (B) shown for an array of 208 passages is 7.38 x 10~5 ^m2 . Using the simplified case where the CPOX reaction temperature is 1000°C (1273°K), the temperature of each surface area AB is 100°C (373°K), and the luminescence rate e = 1.0, Equation 3 becomes We predict that the surface area ABt can absorb about 11 W or about 3.6% of the power generated by the CPOX reaction.

If a gap is provided at the interface (3032) such that the entire solid surface area of the bottom of the reactor shield base wall (3015), denoted AS, is potentially available to absorb thermal energy; The available solid material surface area AS is 2.31 × ^{10−4 m2} , and Equation 3 indicates that the area AS can absorb about 34 W or about 11.3% of the power produced by the CPOX reaction. Predict.

In addition, if the surface area of the inner surface of all 208 circular fuel passages (3095) is potentially available to absorb thermal energy, then the available surface area of all circular fuel passages, denoted by AP, is 1.1043×10 ² m ² and Equation 3 predicts that the surface area AP can absorb about 1632 W or about 211% of the power produced by the CPOX reaction.

As a practical matter, the thermal energy absorption power values listed above are calculated using a view factor Sf=1 for thermal radiation impinging on a surface at normal incidence. As is the case with the surface area ABt, the value Sf=1 is not realistic for the surface areas AS and AP. Furthermore, as a practical matter, the surface emissivity (e) of a heavily oxidized aluminum surface is not 1.0, but is instead about 0.25 or less. Therefore, the energy absorption value can be expressed as Equation 3 with surface emissivity e=0.25 for all three surface areas ABt, AS, and AP, and view factor Sf=1 for surface area ABt, and Sf= If 0.1 is used, it can be expressed more realistically. In this case, Equation 3 states that surface area ABt potentially absorbs about 2.75W, surface area AS potentially absorbs about 0.85W, and surface area AP potentially absorbs about 44.6W. I'm predicting. Therefore, when maintained at about 100° C., the reactor shield base wall (3015) potentially absorbs about 16% of the total power released by the CPOX reaction.

Those skilled in the art will recognize that additional thermal energy can be absorbed by increasing the available surface area or by reducing the temperature of the reactor shield base wall (3015). As mentioned above in accordance with the present disclosure, the surface temperature of the heat dissipation flange (3100) is preferably maintained in the range of 50-100°C. This is likely to maintain the temperature of the entire reactor shield body (3040) at approximately the same temperature due to the high thermal conductivity of the fuel reactor body (3040), but due to the high thermal conductivity of the fuel reactor base wall (3015) and the heat dissipation flange (3100). As mentioned above, this allows the thermal energy to be absorbed from the CPOX reaction and allows the raw fuel passing through the fuel reactor body (3040) to reach its auto-ignition temperature depending on which fuel is being used. Prevent the temperature from reaching 295-580°C.

Therefore, maintaining said reactor shield base wall (3015) at a temperature of 100° C. during operation and providing a small gap of, for example, about 1 mm at the interface (3032) requires a thermal energy of about 43 W, or It has the potential to absorb about 14% of the total energy emitted by the CPOX reaction at a temperature of 1000°C. However, those skilled in the art will appreciate that additional thermal energy can be removed from each of the catalytic fuel passages (3085) by increasing the view factor, increasing the surface area, and reducing the temperature of the fuel reactor body (3040). You will realize that you can.

Operating Mode Cold Start Referring to FIGS. 1-3, the fuel input module (197) is operated by the electronic controller (190) from a cold start to cold start combustion of the fuel-air mixture via the fuel input inlet (2304). The fuel-air mixture within the cold start combustion chamber (2300) is ignited using an electric igniter (2306) operable by the electronic controller (190). Simultaneously or immediately thereafter, the fuel input module (197) is also operative to deliver the fuel/air mixture to the fuel reformer module (3020) via the fuel input conduit (2045), and the fuel/air mixture is delivered to the fuel reformer module (3020). through the fuel equipment module (3020) to the fuel input manifold (2055). Preferably, the initial flow rate of the fuel-air mixture delivered through the fuel reformer module is very low and is only intended to fill the SOFC system with a substantially fixed volume of fuel-air mixture.

The ignited fuel inside the cold start combustion chamber (2300) heats the walls of the cold start combustion chamber (2300), but the top wall (2017) absorbs more thermal energy than the other walls of the cold start combustion chamber. configured to do so. As the temperature of the top wall (2017) increases, thermal energy is thermally conducted from the top wall (2017) to other areas of the hot zone enclosure wall (115). In addition, the top wall (2017) and other walls of the hot zone enclosure (115) begin to emit thermal radiation to the fuel inlet module (2055), which is absorbed by the fuel-air mixture contained therein, increasing its temperature. to rise. Exhaust gases generated by burning the fuel-air mixture within the cold-start combustion chamber (2300) exit from the cold-start combustion chamber (2300) through the cold-start outlet port (2302) and through the air gap (2155). and flows to the system exit port (2165). As the hot exhaust gas flows through the air gap (2010), it radiates thermal energy to the outer surface of the longitudinal cylindrical sidewall (2015) where the temperature increases.

The top wall (2017) is attached to a longitudinal cylindrical side wall (2015) which is further attached to a disk-shaped tube bottom support wall (2084) and a disk-shaped separation wall (2214). Each of the top end wall (2017), longitudinal cylindrical side wall (2015), disc-shaped tube bottom support wall (2084), and disc-shaped isolation wall (2114) collectively form a hot zone enclosure wall (115). do. As mentioned above, each of the hot zone enclosure walls is fabricated from one or more of copper, molybdenum, aluminum copper, copper nickel alloys, or combinations thereof, such that the hot zone enclosure wall structure ( 115) The whole forms a continuous heat conduction path with a thermal conductivity coefficient of about 100-300 W/m°K, preferably greater than 200 W/m°K. Additionally, if any surfaces of the hot zone enclosure walls are exposed to an oxygen-rich environment, the wall surfaces are preferably coated with nickel to prevent oxidation.

In the case of three disk-shaped walls (2017, 2084, and 2214), each of these walls is connected by heat conduction to the fuel inlet manifold (2055), cathode chamber (2010), combustion chamber (2135), Absorbing thermal energy and redistributing the absorbed thermal energy to other areas of the hot zone enclosure wall by re-exhausting it into a cooling zone around each disc shaped wall, such as in the thermal device chamber (2210) configured to provide a thermal mass capable of Therefore, when the top wall (2017) is heated by combustion inside the cold start combustion chamber (2300), thermal energy is absorbed by the top wall (hot zone enclosure walls (2017), 2015, 2084, and 2214). All areas of the hot zone enclosure wall assembly are rapidly conductive until the entire hot zone enclosure wall assembly reaches equilibrium temperature. Furthermore, as thermal energy is absorbed or released by the hot zone enclosure wall, its equilibrium temperature changes substantially uniformly over all areas of the hot zone enclosure wall due to its high thermal conductivity.

Thus, during the start-up period, at least a portion of the thermal energy generated by the combustion of fuel within the cold start combustion chamber (2300) is absorbed by the top wall (2017). A further portion is absorbed by the longitudinal cylindrical sidewall (2015) as the hot exhaust gas flows through the air gap (2155) to the system exit port (2165). As the temperature of the top wall (2017) increases, the top wall (2017) begins to re-release thermal energy into the cooler fuel inlet manifold (2055) containing the fuel-air mixture and/or Whatever flows serves to increase its temperature.

Eventually, the temperature of the fuel air mixture inside the fuel inlet manifold (2055) reaches a reaction temperature suitable for initiating the CPOX reaction. The initial CPOX reaction occurs when the fuel-air mixture heated to the reaction temperature enters the catalytic body input or the catalytic layer adjacent to the top surface where the catalytic body is located at the interface (3032) with the back end or bottom surface of the fuel reformer module (3020). Occurs when contacting (3090). Once the CPOX reaction is initiated at the output ends of some or all of the catalytic fuel passages (3085), the temperature within each catalytic fuel passage (3085) increases over its longitudinal length spreading the CPOX reaction to the interface (3032). CPOX reaction is self-sustaining.

Once a self-sustaining CPOX reaction is achieved, the fuel input module (197) discontinues the flow of the fuel-air mixture to the cold start combustion chamber (2300) to maintain the self-sustaining CPOX reaction and generate electrical power. It is operated to adjust the input rate of the fuel air mixture delivered through the fuel reformer module (3020) as needed. However, combustion within the cold start combustion chamber (2300) may continue until full power DC power output is also self-sustainable. The electronic controller (190) is connected to the system exhaust port (2165) by various sensors including a temperature sensor on the wall of the hot zone enclosure, by a temperature sensor (3135) on the heat dissipation flange (3100), ), by detecting the DC power signal at the DC power output module (140), and by various other sensing means.

To heat the cathode gas, the electronic controller (190) operates the air input module (198) to deliver a flow of air/cathode gas to the air input port (2205). This step can be performed simultaneously with the ignition of the cold start chamber, or even before the ignition of the cold start chamber, but can also be delayed until a self-sustaining CPOX reaction is achieved. Preferably, the initial flow rate of inlet air delivered through the recuperator chamber (2210) is very low, intended to fill the SOFC system with a nearly fixed volume of air.

The incoming air flow exits the cathode supply tube (2145) via the recuperator input port (2235), passes through the recuperator chamber (2210) to the recuperator output port (2235), and enters the cathode. The supply tube (2145) exits the cathode chamber (2010) via a plurality of air outlet ports (2240). After reacting with the solid oxide cathode electrode formed on the outer surface of each tubular fuel cell (2080), the air/cathode gas exits the combustion chamber (2135) and is combusted through the cathode chamber outlet port (2245). It passes to chamber (2135) where it mixes with the spent fuel air mixture and combusts. Combustion byproducts then exit the combustion chamber through the combustor exit port (2150) into the air gap (2155) and exit the system through the system exit port (2165).

The primary air heating element is a disc-shaped isolation wall (2214) located inside the recuperator chamber (2210). As mentioned above, the disc-shaped isolation wall (2214) is part of the hot zone enclosure and thus increases the temperature of the disc-shaped top wall (2017) that forms the base wall of the cold start combustion chamber (2300). At about the same time, the temperature begins to increase during the start-up phase. In addition, a disc-shaped isolation wall (2214) is thermally conductively coupled to a disc-shaped tube bottom support wall (2084), both walls of which contain a mixture of spent fuel and spent air inside the combustion chamber (2135). is heated by burning. Therefore, at approximately the same time that the disc-shaped top wall (2017) radiates sufficient thermal energy into the fuel input manifold (2055) to begin increasing the fuel temperature, the disc-shaped isolation wall (2214) ) to begin raising the temperature of the incoming air. At the same time, the hot zone enclosure wall is radiating thermal energy to the cathode chamber (2010), which serves to heat the air contained within and the walls of the tubular fuel cells of the fuel cell stack (2005). . Once the CPOX reaction becomes self-sustaining, the flow rates of both the incoming air and fuel-air mixture can be adjusted as necessary to maintain the self-sustaining CPOX reaction and produce power at the desired power output amplitude. .

8.8.2 SOFC Reaction Initiation As mentioned above, the fuel-air mixture and incoming air/cathode gas are heated by the hot zone enclosure wall, which is heated by the combustion occurring inside the cold start combustion chamber (2300). Ultimately, a self-sustaining CPOX reaction is initiated inside the catalytic fuel passages (3085), which heats the fuel-air mixture to a higher temperature, and the fuel is transferred onto the inner surface of each of the tubular fuel cells (2080). is reformed into synthesis gas that can react with the solid oxide anode electrode formed on the oxide. The higher temperature syngas also radiates thermal energy to the anode electrode as it passes through the tubular fuel cell (2080). As the temperature of the anode electrode increases, the cathode electrode absorbs thermal energy that is radiated into the cathode chamber (2010) by the longitudinal cylindrical sidewall (2015) and enters the cathode chamber (2010) from the recuperator chamber (2210). Heated by heated air/cathode gas.

Eventually, the anode and cathode electrodes, the synthesis gas, and the air/cathode gas inside the cathode chamber reach the reaction temperature and DC power begins to be generated and output to the DC power terminal. Eventually, the gas temperature inside the combustion chamber (2135) reaches the combustion temperature, and the thermal energy generated by the combustion occurring inside the combustion chamber increases the incoming air temperature to the steady state operating temperature. In one non-limiting example mode of operation, the syngas, inlet air, and tubular fuel cell (2080) have a steady state operating temperature of 350-1200°C, with a preferred operating temperature range of 800-1000°C. It is. On the other hand, the hot zone enclosure wall (115) is configured such that the hot zone enclosure wall temperature increases and decreases substantially uniformly over all areas thereof until a steady state operating temperature is reached and then maintained. , constantly redistributing thermal energy by thermal conduction.

Fuel Reformer Modes of Operation Referring now to FIGS. 3-4A, as described above, the fuel reformer module (3020) is configured such that the fuel-air mixture within the fuel chamber (3005) is in the cylindrical catalyst body (3030). ) is at least partially thermally isolated from the cold start combustion chamber (2300) and the hot zone enclosure walls to prevent it from reaching its autoignition temperature. More specifically, depending on the fuel used, the fuel auto-ignition temperature range is about 295-580°C. Comparing the operating temperature range of SOFC systems, it is 350 to 1200°C, depending on the fuel and the material of the electrode layer. Additionally, as mentioned above, the CPOX reaction temperature range is estimated to be 900-1000°C.

During a cold start, the fuel-air mixture (3020) enters the cylindrical fuel chamber (3005), passes through the reactor shield base wall (3015), then passes through the cylindrical catalyst body (3032) and into the fuel input manifold (3055). ) to reach. The fuel-air mixture then passes through the tubular fuel cell and finally exits the system. As mentioned above, the present disclosure provides for the transfer of thermal energy to the disk-shaped top wall (2017) of the hot zone enclosure rather than to the other cold start combustion chamber walls (2510 and 2511) and (2513). The thermal energy generated by combustion within the cold start combustion chamber (2300) is managed in a manner that facilitates. This is managed by configuring the disc-shaped top wall (2017) with a greater thermal mass than the combined thermal mass of the other walls (2510 and 2513).

More specifically, thermal energy transfer (Q) is determined by the following equation 4.
Q=Q=C _th ΔTQ equivalent 4

where Q = thermal energy transfer (J), C _th = thermal mass of the wall (J/°C), and ΔT = temperature difference between the hot gas and the wall.

In this example, ΔT is approximately the same for each wall, but the thermal mass for each wall is different. Thermal mass C _th is defined as the product of the component material mass (m) in units (g) of the component material and the specific heat capacity (μ) in units (J/g °C), where the mass (m ) is the product of the component material volume V in units (cm ³ ) and the material density (ρ) in units (g/cm ³ ).
C _th = ρVμ equivalent 5

where ρ = material density (g/cm ³ ), V = material volume (cm ³ ), and μ = material specific heat capacity of the material (J/g° C.).

In a non-limiting exemplary embodiment, the disk-shaped top wall (2017) of the hot zone enclosure is comprised primarily of copper and is joined to the other wall (2510) of the intermediate enclosure surrounding the cold start combustion chamber (2300). ), (2511), and (2513), each further surrounding a hot zone enclosure containing mostly Hastelloy. For copper, the specific heat capacity (μ) is 0.385 J/g°C. For Hastelloy, a cobalt-nickel-chromium-tungsten alloy that combines excellent high-temperature strength up to 2000°F (1095°C) with very good resistance to oxidizing environments, the specific heat capacity (μ) is 0.450 J/g. It is ℃. For copper, the density (ρ) is 8.96 g/cm ³ and for Hastelloy, the density (ρ) is 8.22 g/cm ³ . It is the (Q _t ) is larger than all (Q _o ) of the other connected walls, which, expressed in terms of Equation 4 when the term ΔT is the same for each wall, simplifies as be done.
C _th t>C _th o or (ρ _c Vtμ _c )>(ρ _h Voμ _h )

where C _th t = thermal mass of the top wall, C _th o = combined thermal mass of other walls, Vt = volume of top wall, Vo = combined volume of other walls, ρ _c = Density of copper, ρ _h = density of Hastelloy, and μ _c = specific heat of copper, μ _h = specific heat of Hastelloy.

As a result of this example,
Vt>1.07Vo.

In other words, when the volume (Vt) of the disk-shaped top wall (2017) exceeds 1.07 times the combined volume (Vo) of the other walls (2510 and 2513), the thermal mass of the top disk-shaped top wall (2017) exceeds the thermal mass of the other cold start combustion chamber walls (2510 and 2513). Thus, according to the present disclosure, the thermal mass of the upper disc-shaped top wall (2017) exceeds the thermal mass of the intermediate enclosure walls (2510 and 2513), preferably by more than 100%. To calculate (Vo) above, only the walls actually surrounding the cold start chamber (2300) are considered. In the example above, (Vo) includes the entire volume of the wall (2513) and only the portion of the wall (2510) that actually surrounds the cold start chamber (2300). Using this model, when the volume of the disk-shaped top wall (2017) (Vt) is 2.14 times (Vo), the thermal mass of the wall (2513) and the portion of the wall (2510) surrounding the cold start chamber exceeds 100%.

As a result, more thermal energy is absorbed by the top wall (2017) than is absorbed by all other cold start combustion chamber walls. The main advantage of this embodiment is that the top wall (2017) absorbs most of the thermal energy generated by the fuel-air mixture combusted inside the cold start combustion chamber (2300). Because the top wall and other hot zone enclosure walls are more thermally conductive than walls (2510 and 2513), thermal energy absorbed by the top wall is transferred by the thermal conduction path formed by the hot zone enclosure walls. Conducted rapidly. This means that the intermediate enclosure walls (2510, 2511, and 2513) and the annular enclosure wall (7060) are much more distant from the hot zone enclosure wall than through Hastelloy or through the hot zone enclosure wall. It is further facilitated by forming it from another high nickel-containing metal with a thermal conductivity coefficient of less than about 25.0 W/m°K, which results in a slow conductive heat flow.

During the cold start process, the combustion energy from the cold start chamber is primarily absorbed by the top end wall (2017) and re-released into the fuel inlet manifold (2055) to direct the fuel-air mixture contained therein to the catalytic fuel passages. Heat sufficiently to achieve a temperature high enough to initiate the CPOX reaction at the output end (3034) of (3085). A side advantage of this embodiment is that the majority of the thermal energy generated by the fuel-air mixture combusted inside the cold-start combustion chamber (2300) is instead transferred from the disk-shaped top wall (2017) to other hot sources. Flows away from the fuel reformer module (3020) by providing higher conductive heat flow through the zone enclosure walls (2015 and 2511), as well as the disc-shaped separator wall (2214) and disc-shaped tube bottom support wall (2084). That's true.

Once the CPOX reaction is initiated and self-sustaining, the fuel reactor body (3040) has sufficient thermal mass to rapidly conduct heat transfer paths and thermal energy from the reactor shield base wall (3015) to the heat dissipation flange (3100). I will provide a. In particular, since the interface (3032) is in close proximity to the CPOX reaction, which has a temperature of 900-1000°C, thermal energy reaches the reactor shield base wall (3015) in varying amounts by radiation, thermal conduction, and convection. , by the remaining solid material of the exposed surface (b) and the bottom of the reactor shield base wall (3015), as well as the inner surface of the circular base wall fuel passageway (3095) shown in FIGS. 4 and 4A. As a result, the initial CPOX reaction proximate to the interface (3032) is effectively quenched and auto-ignition of the incoming fuel-air mixture is prevented. The combined surface area (B), denoted ABt, potentially absorbs approximately 1% of the total thermal radiation emitted from all catalytic fuel passages (3085) and the reactor shield base wall at the interface denoted AS above. The solid surface area potentially absorbs about 0.2% of the total thermal radiation emitted from all catalytic fuel passages (3085), and the internal surfaces of the base wall fuel passages (3095) absorb about 15% of the total total. Potentially absorbs 13.6%.

According to the present disclosure, the thermal mass of the reactor shield base wall (3015), i.e., its material volume (see Equation 5 above), provides sufficient energy transfer from the catalytic fuel passageway (3085) to It is made large enough to prevent excessive heating therein when the shield base wall can be maintained below 100°C. In addition, according to the present disclosure, the thermal mass of the fuel reactor body (3040), i.e. its material volume, provides sufficient energy transfer by heat conduction from the reactor shield base wall (3015) to the heat dissipation flange (3100). The entire fuel reactor body (3040) is maintained at a small temperature gradient between the higher temperature reactor shield base wall and the heat dissipation flange (3100), so that approximately A uniform temperature can be maintained. Further, according to the present disclosure, the surface area of the heat dissipation flange (3100) is large enough to match the rate of thermal energy absorbed by the reactor shield base wall (3015), which is approximately 44 W as discussed above. Thermal energy is dissipated from it at an equal rate. Further, according to the present disclosure, the fuel reactor body (3040) is configured to dissipate sufficient heat therefrom such that the fuel-air mixture passing through the cylindrical fuel chamber (3005) does not exceed its auto-ignition temperature. configured. More specifically, the heat dissipation flange (3100) equals the lowest auto-ignition temperature of the expected fuel-air mixture and preferably maintains the temperature of the entire fuel reactor body (3040) between about 100 and 250 during all modes of operation. The fuel reactor body (3040) is configured to dissipate sufficient thermal energy to the outside air to maintain the temperature of the fuel reactor body (3040) below about 295°C so as to maintain the temperature between 295°C and 295°C. Also, according to the present intent, the temperature of the heat dissipation flange (3100) is monitored during all operating phases, and when the temperature of the heat dissipation flange (3100) exceeds the desired high temperature limit, the incoming fuel-air mixture is may be stopped by an operable element of the fuel input module (197) to prevent fuel from entering the reformer (167) until further operation, or the air movement element (3130) may be stopped by an operable element of the fuel input module (197) to prevent fuel from entering the reformer (167) until further operation; The temperature of (3100) may be reduced to a safe operating temperature.

Alternative Fuel Reformer and Outer Enclosure Embodiment Referring now to FIGS. 2-4 and 7, an exemplary, non-limiting, alternative embodiment of a SOFC system (7000) is a fuel reformer and outer enclosure embodiment. Includes alternative embodiments of device module (7020) and related elements. The SOFC system (7000) is substantially identical when compared to the systems (2000 and 3000) shown in FIGS. 2-4, except for additional features and different modes of operation of the system (7000) as outlined below. construction and has a similar mode of operation. To clarify the similarities and differences between the systems, in the following SOFC system embodiments (2000, 3000, and 7000), the referenced items are substantially Similar reference numbers are used if they have the same structure.

Referring to FIG. 7, an alternative fuel reformer module (7020) includes an annular perimeter wall (7010) attached to or integrally formed with a reactor shield base wall (7015). Includes a furnace body (7040). The fuel reactor body (7040) is configured to provide a cylindrical fuel chamber (7005) surrounded by an annular peripheral wall (7010), a reactor shield base wall (7015), and a disk-shaped outer enclosure top flange (7102). is formed. A fuel inlet conduit (7045) is disposed to pass through the disc-shaped outer enclosure top flange (7102) and into the fuel chamber (7005).

The fuel reformer module (7020) further includes the cylindrical catalyst body (3030) described above. Each of the fuel reactor body (7040) and cylindrical catalyst body (3030) is arranged such that the cylindrical catalyst body (3030) is located directly above the fuel inlet manifold (3055), and the fuel furnace body (7040) is located directly above the cylindrical catalyst body (3055). (3030) located in a cylindrical catalyst cavity (7035). Each of the fuel reactor body (7040) and cylindrical catalyst body (3030) is located between the cylindrical fuel chamber (7005) and the fuel inlet manifold (3055), as shown in FIGS. 4 and 4A and described above. configured to provide fluid communication at the. The fuel reactor body (7040) has a thermal conductivity coefficient greater than 100 W/m°K and rapidly conducts thermal energy from the interface between the reactor shield base wall (7015) and the catalyst body (3030). formed using a material that has sufficient thermal mass to

In this alternative non-limiting embodiment of the SOFC system (7000), the cylindrical catalyst cavity (7035) has a sidewall formed by the inner diameter of the annular enclosure wall (7060). The inner diameter of the annular enclosure wall (7060) is formed with a central longitudinal axis disposed coaxially with the central longitudinal axis (2060). Cylindrical catalyst cavities (7035) each form a circular opening with a top circular opening facing the disk-shaped outer enclosure top flange (7102) and a bottom circular opening facing the fuel inlet manifold (3055). , including two open ends. The annular enclosure wall (7060) includes an annular seal plate (7105) surrounding the top circular opening that mechanically interacts with the disc-shaped outer enclosure top flange (7102), the annular seal plate (7105) , attached to the disk-shaped outer enclosure top flange (7102) by mechanical fasteners or the like (not shown). An O-ring sealing element (7110) or the like is disposed between the annular sealing plate (7105) and the disk-shaped outer enclosure top flange (7102), for example in the O-ring groove, and is located in the upper part of the cylindrical catalyst cavity (7035). It plays the role of gas sealing the parts.

A disc-shaped outer enclosure top flange (7102) is attached to the outer cylindrical sidewall (2514), and the joint between the two elements provides a continuous heat transfer path. Like the fuel reactor body (7040) and other outer envelope walls (2514) and (2518), the outer envelope top flange (7102) has a thermal conductivity coefficient greater than 100 W/m°K and has an atomic Formed from a material having sufficient thermal mass to rapidly conduct thermal energy from the interface between the furnace shield base wall (7015) and the catalyst body (3030). As mentioned above, thermal energy absorbed by the outer enclosure top flange (7102) is transferred to the outer cylindrical wall (2514) to minimize temperature gradients from one region of the outer enclosure to another. Conducted rapidly. The disk-shaped outer enclosure top flange (7102) is attached to the outer cylindrical wall (2514) by mechanical fasteners (not shown), such as by welding, soldering, or the like. In any event, the joint formed between the top flange (7102) and the outer cylindrical wall (2514) is gas sealed and provides a substantially continuous heat transfer path.

As mentioned above, the reactor shield base wall (7015) is configured to absorb thermal energy generated within the cylindrical catalyst body (3030). The entire fuel reactor body (7040) rapidly conducts thermal energy generated within the cylindrical catalyst body (3030) to the disk-shaped outer enclosure top flange (7102) and then to the cylindrical side wall (2514) and outer bottom wall. (2518) and is configured to provide a continuous heat conduction path to the disc-shaped top flange (7102). Therefore, a change in the instantaneous temperature of the reactor shield base wall (7015) is followed by a corresponding rapid change in temperature throughout the outer enclosure.

8.10 Thermal Energy Transfer from the Hot Zone Enclosure to the Outer Enclosure As detailed above, each wall of the outer enclosure (2514), (2518), (7102) has a °K, preferably more than 140 W/m°K. Accordingly, the outer cylindrical side wall (2514), the disc-shaped outer bottom wall (2518), and the disc-shaped outer enclosure top flange (7102) are made of copper, molybdenum, aluminum-copper, copper-nickel alloy, or combinations thereof. Manufactured from one or more. Each of walls (2514), (2518), and (7102) preferably has a thermal conductivity coefficient of greater than 140 W/m°K, and each Contains aluminum or an aluminum alloy with sufficient thermal mass, i.e., thickness, to rapidly conduct thermal energy to the wall. In this non-limiting exemplary embodiment, the outer cylindrical wall (2514) and the disc-shaped outer bottom wall (2518) have a material thickness ranging from 0.5 to 6.5 mm (0.20 to 0.25 inches). and the outer enclosure top flange (7102) has a material thickness in the range of 4.0 to 10.0 mm (0.16 to 0.39 inches), although other thickness ranges are contemplated by the present disclosure. It can be used without deviation.

Specifically, each of the outer enclosure walls (2514, 2518, 7102) is configured to provide a temperature gradient from one region of the outer enclosure to another to more rapidly reduce temperature gradients between regions of the outer enclosure. The outer enclosure wall structure is configured such that the entire outer enclosure wall structure remains at substantially the same uniform temperature throughout, providing a substantially continuous thermal conduction path for rapidly transferring thermal energy by thermal conduction. Ru.

As further discussed above, the hot zone enclosure walls (2015, 2016, and 2017) and (2214 and 2080) more rapidly reduce the temperature gradient between the hot zone enclosure walls and the hot zone enclosure wall structure. It forms a continuous heat transfer path suitable for rapid heat transfer from one area of the hot zone enclosure wall to another to maintain substantially the same temperature throughout. The intermediate enclosure walls (2510, 2511, and 2513) are thermally conductively coupled to the hot zone enclosure wall by a disk-shaped end wall (2017). As detailed above, each of the intermediate enclosure walls has a thermal conductivity of less than about 25.0 W/m°K, compared to a thermal conductivity coefficient of the hot zone enclosure wall of 100 W/m°K or more. Contains materials with a rate of Additionally, the disk-shaped walls (2017, 2084, and 2214) provide greater thermal mass compared to the less thermal mass provided by the intermediate enclosure walls. As a result, the hot zone enclosure walls absorb and conduct thermal energy at a faster rate than the intermediate enclosure walls. The hot zone enclosure wall is thermally conductively connected to the intermediate enclosure wall by a disc-shaped wall (2017), but the connection is Intentionally reduce thermal mass. This provides a temperature gradient between the hot zone enclosure wall and the intermediate enclosure wall. The advantage of the temperature gradient established between the hot zone enclosure wall and the intermediate enclosure wall is that the thermal radiation emitted from the hot zone enclosure wall increases due to the inflow cathode into the recuperator chamber (2210). The purpose is to heat the air and the air present in the cathode chamber (2010) more rapidly.

As described in more detail on each wall of the outer enclosure (2514, 2518, and 7102), having a high thermal conductivity coefficient, for example from 100 to 300 W/m°K, preferably greater than 140 W/m°K. Including materials. Accordingly, the outer cylindrical sidewall (2514), the disc-shaped outer bottom wall (2518), and the disc-shaped outer enclosure top flange (7102) are made of one or more of copper, molybdenum, aluminum, nickel, or alloys thereof. It is produced from. In one non-limiting embodiment, the walls (2514, 2518, 2516, and 7102) preferably include aluminum or an aluminum alloy with a thermal conductivity coefficient greater than 140 W/m°K. Further, each of the walls (2514, 2518, 2516, and 7102) is formed with sufficient thermal mass, i.e., thickness or total volume, such that throughout its volume, e.g. Rapidly conduct thermal energy to another wall. In the present non-limiting exemplary embodiment shown in FIGS. 3 and 7, the outer enclosure walls (2514 and 2518) are made of material ranging from 0.5 to 6.5 mm (0.02 to 0.25 inches). , and the wall (7102) has a material thickness ranging from 4.0 to 10.0 mm (0.16 to 0.39 inches), although other thickness ranges are contemplated by the present disclosure. It can be used without deviation. In the present non-limiting exemplary embodiment shown in FIGS. 2 and 7, the hot zone walls (2015) and (2016) are made of material ranging from 0.5 to 13 mm (0.02 to 0.5 inches). thickness, although other thickness ranges can be used without departing from this disclosure.

The layer of insulation material (2512)
Disposed between the outer surface of the intermediate enclosure wall and the inner surface of the outer enclosure wall. Preferably, the thermal insulation layer (2512) is configured such that the surfaces of the outer cylindrical sidewall (2514), the disc-shaped outer bottom wall (2518), and the disc-shaped outer enclosure top flange (7102) are heated to a desired temperature, e.g., 95-110°C. Constructed to ensure it stays within operating temperature range.

The annular enclosure walls (7060) each include a high temperature resistant material such as Hastelloy or Monel, each having a high nickel content to resist oxidative damage, and each having a suitable service temperature rating of, for example, greater than 400°C. However, the thermal conductivity coefficients of both Hastelloy and Monel are less than about 25.0 W/m°K. Additionally, the annular enclosure wall (7060) is formed with a wall thickness in the range of 0.02 to 0.1 inches; however, in any event, the annular enclosure wall (7060) has a thickness of To reduce the relative thermal mass of the annular enclosure wall (7060), the thermal mass of the thermally conductive walls of the hot zone enclosure wall when compared to the thermal mass of the hot zone enclosure wall and the intermediate enclosure wall. selected to provide a lower thermal mass than Therefore, due to its low thermal conductivity and reduced thermal mass, the annular enclosure wall (7060) resists conductive thermal energy transfer between the hot zone enclosure wall and the outer enclosure wall to Maintaining a temperature gradient between the enclosure wall and the outer enclosure wall. However, this resistance to conductive thermal energy transfer by the annular enclosure wall (7060) only reduces the thermal conductivity or heat flow from the hot hot zone enclosure wall to the cooler outer enclosure wall. More specifically, the annular enclosure wall (7060) configuration provides a temperature gradient between the hot zone enclosure walls.

Overtemperature Protection System Excessive heat generation at various locations within the SOFC system (7000) can result in potentially dangerous and harmful overtemperature conditions. During operation, overtemperature conditions occur within the cell stack (2005), within the cylindrical catalyst body (7030), and within or adjacent to the combustion chamber (2135), within or adjacent to the cold start combustion chamber (2300). It may occur in other locations, such as in close proximity and/or inside the air gap (2155).

Overtemperature conditions can rapidly escalate and lead to catastrophes such as destruction of the SOFC fuel cell, explosion, or fire. Overtemperature conditions often lead to burn-through, where the metal wall is partially melted or damaged and the insulation layer (2512) is destroyed or permanently rendered ineffective. A catastrophic failure may include fuel combustion within a cylindrical fuel chamber (3005) that is not intended for fuel combustion. Therefore, if an overtemperature condition occurs anywhere in the SOFC system, fuel must enter the SOFC system (7000) as soon as possible before the overtemperature condition leads to catastrophic failure or damage the SOFC system. It is desirable to stop.

Conventional SOFC systems use internal temperature sensors to monitor internal temperature. Temperature sensors are located within the SOFC system in close proximity to critical areas where overheating or cold conditions can adversely affect the performance of the SOFC system. Each internal temperature sensor is in communication with the electronic controller via a wired communication interface. The electronic controller interprets the temperature signal received from the internal temperature sensor and executes software or other logical process steps to monitor and record the temperature sensor input. Generally, the electronic controller (190) stores temperature limit ranges in a memory module, each temperature limit range for a different operating mode and/or a different internal sensor location. One problem with internal temperature sensors is that they cannot be easily replaced if they fail. Additionally, internal temperature sensors in SOFC systems are in a hot and often contaminated environment that can shorten the sensor's useful life. External temperature sensors are used in the art to determine SOFC temperature levels, preferably a single external temperature sensor that can be used to trigger various SOFC system process controls. It is necessary to determine the instantaneous SOFC surface temperature.

According to the present disclosure, process control may be triggered by changes in temperature monitored by a single external temperature sensor. In one exemplary embodiment described above, the operation of the air moving device (3130) shown in FIG. 3 is responsive to changes in the temperature of the exterior surface of the SOFC system (3000). In particular, an electronic controller (190) using a temperature sensor signal from an external temperature sensor (3135) turns the air moving device (3130) on or off in response to an instantaneous temperature change indicated by the external temperature sensor (3135). Switch to

Referring to FIG. 7, the SOFC system (7000) includes an external temperature sensor (7135) mounted in contact with the outer surface of the disk-shaped outer enclosure top flange (7102). Alternatively, an external temperature sensor (7135) may be mounted in contact with any exterior surface of the outer enclosure wall. External temperature sensing element (7135) communicates with electronic controller (190) and delivers temperature signals to electronic controller (190) via communication path (7140). In various embodiments, the SOFC system (7000) may also include an air movement element (3130), shown in FIG. 3 and described above, which is operable by an electronic controller (190). The air is then moved over the disk-shaped outer enclosure top flange (7102) to reduce its temperature.

In an exemplary mode of operation, electronic controller (190) receives a temperature signal from external temperature sensing element (7135) via communication path (7140) and determines the instantaneous temperature of the external surface to which the external temperature sensing element is attached. do. If the instantaneous temperature is not within the expected temperature range, the electronic controller is programmed using software and other logical operators to perform various operating procedures in response to the out-of-range instantaneous temperature value.

In the first example, the SOFC system is operating in a normal operating mode producing DC output power, with incoming fuel entering the fuel chamber (7005) from the fuel input module (197), as shown in FIG. Operating with a steady and uniform flow of air mixture.

The fuel input module (197) includes an operable fuel supply valve (7610). An operable fuel supply valve is disposed between the fuel source and the fuel reformer (7020) along a fuel input conduit (7045). The operable fuel supply valve communicates with the electronic controller (190) via a communication channel (7666) and with an electrical power source via a power conduit (7830), not shown. The operable fuel supply valve (7610) has a default state in which the valve is closed, eg, held closed, such as by a spring force. The valve is operated by an electronic controller (190) and is opened by overcoming a spring force when a power signal is applied within the valve or to an actuator incorporated within or associated with the valve. .

In one non-limiting embodiment, the electronic controller (190) applies a power signal to the valve actuator to overcome the spring force and open the fuel delivery valve (7610). Depending on the amplitude of the power signal, the valve may be slightly open, e.g. at a threshold power signal amplitude, or the valve may be fully open, e.g. at a maximum power signal amplitude. You can. In operation, the electronic controller (190) moves the valve actuator between a range of slightly or partially open and fully open states in response to changes in the amplitude of the power signal delivered to the valve actuator. is operable to vary the power signal amplitude in a manner that causes the power signal to move to an open position. The electronic controller (190) controls the flow of the fuel-air mixture (3025) passing through the input conduit (7045) into the cylindrical fuel chamber (7005) by varying the amplitude of the power signal on the power conduit (7830). Operates to regulate mass or volume flow.

In the operating mode of the present disclosure, the electronic controller (190) monitors the external temperature sensing element (7102) to determine the instantaneous temperature of the disc-shaped top flange (7102). A software program or other logical operator running on the electronic controller (190) compares the measured instantaneous temperature of the top flange to a temperature range associated with the current operating mode of the SOFC system. The temperature ranges for the different operating modes are stored in a memory associated with the electronic controller (190). Non-limiting example modes of operation include a start-up mode of operation when a cold-start combustion chamber (2300) is used, a steady-state mode of operation when the cold-start combustion chamber is not used, and a fuel stack output Others include the flow rate of incoming fuel being adjusted to provide more or less DC power.

In either case, if the instantaneous temperature sensed by the external temperature sensing element (7102) is within the expected temperature range, the electronic controller will not operate. However, if the instantaneous temperature sensed by the external temperature sensing element (7102), ie, the temperature of the top flange (7102), is not within the expected temperature range, the electronic controller (190) is activated.

As a safety feature, the expected temperature range for any of the operating modes has an upper limit called the "controller fail-safe temperature." In this non-limiting example mode of operation, the fail-safe temperature of the controller is 140°C. In particular, if the instantaneous temperature measured by the external sensor (7135) is greater than or equal to 140°C, the electronic controller will initiate a safe shutdown procedure that includes disconnecting power to the operable fuel supply valve (7610) actuator. Initially, at least prevent further fuel flow into the SOFC system.

When the controller fail-safe temperature is sensed, the electronic controller performs a software or logical process that includes commanding the fuel supply module (197) to close the fuel supply valve (7610) by disconnecting power. Starts a controlled shutdown process. In addition, the controlled shutdown process will stop fuel delivery to the cold start combustion chamber (2300) if the SOFC system is so equipped and if the air moving device is no longer operating, the air input It may include stopping air input by module (198) and activating air movement device (3210).

More generally, a single external temperature sensing positioned on any surface of the outer enclosure due to the thermal conduction path and relatively high thermal conductivity provided by the improved outer enclosure of the present disclosure. Element (7135) eccentrically senses the instantaneous temperature across the outer enclosure wall (132).

In a further aspect of the disclosure, a thermal fuse (7860) including a fusible link is in contact with the outer surface of the disk-shaped outer enclosure top flange (7102) or in contact with any outer surface of the outer enclosure. will be placed. A thermal fuse (7860) is disposed along the fuel supply power conduit (7830) between the source power source and the operable fuel supply valve (7610). The thermal fuse (7860) is a passive device and is independent of the electronic controller (190). The thermal fuse (not shown) transfers power from the supply valve power supply to the operational fuel supply valve (7610) such that it is interrupted when the fusible link melts and creates a short circuit within the thermal fuse (7860). It is composed of The meltable link has a specific melting temperature that is equal to the fail-safe temperature of the system. In this non-limiting exemplary embodiment, the fail-safe temperature of the system is equal to a temperature that is higher than the fail-safe temperature of the controller. In one non-limiting exemplary mode of operation, the fail-safe temperature of the system is 180°C. Especially if the temperature of the meltable link reaches the system fail-safe temperature of 180°C. The fusible link melts, causing a short circuit across the thermal fuse (7860). A short circuit causes the power amplitude to zero with the valve (7610) operable to close. Therefore, flow of fuel into the fuel chamber (7005) is prevented. In an exemplary, non-limiting embodiment, the thermal fuse (7860) is any one of the commercially available thermal fuses, such as the Tamura LE series, the NEC Sefuse SF series, the Microtemp G4A series, and the Hot Elmwood D series. The selected fuse is comprised of a fusible link that melts at the desired system fail-safe temperature.

As described above, the system (7000) is operable to perform a software or logical shutdown procedure when a single external temperature sensor (7135) reports an instantaneous temperature equivalent to the fail-safe temperature of the controller. an electronic controller (190). The software or logical shutdown procedure includes at least closing the operable fuel supply valve (7610) using logical commands. On the other hand, if the fusible link of the thermal fuse (7860) reaches the fail-safe temperature of the system, the thermal fuse will prevent power from reaching the operational fuel supply valve (7610), so the software or Fuel flow to the fuel chamber is stopped if fuel flow was not previously stopped by a logical shutdown procedure.

Each of the outer enclosure walls (2514, 2518, and 7102) is configured to provide a heat transfer path with a high thermal conductivity coefficient such that the entire outer enclosure wall structure is substantially Thermal equilibrium is quickly reached at the same instantaneous temperature. Accordingly, temperature sensing element (7135) and thermal fuse (7860) can be located on any exterior surface of the outer envelope, including on different exterior surfaces of the outer envelope. Additionally, as described above, the instantaneous temperature of the outer enclosure increases and decreases in response to increases and decreases in temperature of the hot zone enclosure wall that is thermally conductively connected on the annular enclosure wall (7060). . Therefore, any prolonged increase in instantaneous temperature at any location within the SOFC system (7000) will result in an increase in the temperature of the outer enclosure wall as monitored by the electronic controller (190) and, ultimately, Detected by external temperature sensing element (7135).

Fuel/Oxidizer Input Control Module Referring now to FIG. 8, a schematic representation of a further non-limiting, exemplary embodiment of a solid oxide fuel cell (SOFC) system (8000) according to the present disclosure is shown. There is. The SOFC system (8000) includes a fuel/oxidizer input control module (8005), also shown as a fuel input module (197) in FIG. A fuel/oxidant input control module (8005) includes or is fluidly coupled to each of an oxidant source (8010) and a hydrocarbon fuel source (8020). The oxidant source (8010) is in fluid communication with a mixing chamber (8015), such as a helical mixing chamber, by a connecting oxidant input conduit (8017). A fuel supply (8020) is in fluid communication with the mixing chamber (8015) by a connecting fuel input conduit (8022). An oxidant flow modulator (8025) is disposed along the oxidant input conduit (8017) between the oxidant source (8010) and the mixing chamber (8015). A hydrocarbon fuel flow modulator (8035) is disposed along the fuel input conduit (8022) between the hydrocarbon fuel source (8020) and the mixing chamber (8015). Each flow modulator (8025, 8035) includes at least one electromechanical actuator, not shown, controlled by an electronic controller (190). The electronic controller (190) is configured to independently adjust the input oxidant flow rate and the input hydrocarbon fuel flow rate to the mixing chamber (8015). Each of the input oxidant flow rate and the input hydrocarbon fuel flow rate may be adjusted between substantially zero input flow rate and a maximum input flow rate. In an alternative embodiment, the mixing chamber (8015) is eliminated and each of the oxidant input conduit (8017) and the fuel input conduit (8022) are connected to the fuel reactor shown in FIGS. 3, 4, 4A, and 7. A connection is made between a corresponding supply source formed inside the system (3000) and a fuel chamber (3005).

Compressed Gas Container In one non-limiting, exemplary embodiment, one or both of the oxidant source (8010) and the hydrocarbon fuel source (8020) are compressed gas containers, e.g. An oxygen or air container, or a pressurized hydrocarbon fuel container. In either case, the pressurized vessel includes a passive pressure regulator, not shown. A passive pressure regulator is disposed between the compressed gas container and the mixing chamber (8015) and is operative to pressure regulate or regulate the flow of high pressure gas exiting the compressed gas container. The flow of low pressure gas is discharged by the pressure regulator into the corresponding input conduit (8017, 8022), the low pressure gas being discharged at a much lower gas pressure compared to the high pressure gas stored inside the compressed gas container. . Passive pressure regulators also function as passive gas flow modulators. This occurs when the low pressure gas exiting the mixing chamber (8015) from the corresponding input conduit (8017, 8022) reduces the gas pressure inside the corresponding conduit. In response to a decrease in gas pressure, within the corresponding conduit, a passive pressure regulator causes the pressure in the corresponding conduit to increase from the pressurized gas container until the gas pressure in the corresponding conduit is restored to the set pressure of the passive gas regulator. Release gas inside. Thus, the gas flow rate leaving any one of the input conduits (8017, 8022), for example into the mixing chamber (8015), is replaced by the corresponding gas flow rate emitted by the corresponding passive pressure regulator. Each gas regulator thus operates to maintain a constant gas pressure within the corresponding input conduit (8017, 8022).

Air Pump/Fan In another non-limiting, exemplary embodiment, the oxidant source (8010) is an air pump or fan, etc. that draws air from the ambient environment or air inlet into the oxidant input conduit (8017). . In one non-limiting, exemplary embodiment, the air pump or fan also includes an oxidant flow modulator when the air pump or fan includes a controllable electromechanical actuator in communication with an electronic controller (190). (8025). A controllable electromechanical actuator (not shown) operates to rotate a controllable air moving device, such as a pump vane, fan blade, etc., or otherwise be associated with an air pump or fan. Movement of the air moving device directs or draws oxidant into the oxidant input conduit (8017), and the oxidant fuel flow rate increases the angular velocity of a rotating pump vane or fan blade, for example, by changing the speed of the air moving device. Change by changing. Changes in speed of the air moving device are driven by control and command signals received from the electronic controller (190). Command and control signals received by the air moving device adjust the speed of the air moving device corresponding to adjusting the flow rate of air through the oxidant input conduit (8017) to the mixing chamber (8015). When operating as an oxidant flow modulator (8025), the air pump or fan is controlled by an electronic controller (190) to adjust the fluid flow rate of air through the oxidant input conduit (8017) and into the mixing chamber (8015). is operated to adjust between substantially zero oxidant flow rate and maximum oxidant flow rate.

In a further non-limiting embodiment, the oxidant source (8010) is an air pump or fan that draws air into the oxidant input conduit (8017) from the ambient environment or from an air inlet or the like at a substantially constant air flow rate. , air flow modulation is performed by a gas control valve described below.

Liquid Fuel Supply In another non-limiting, exemplary embodiment, the hydrocarbon fuel source (8020) includes a liquid hydrocarbon fuel, such as kerosene, gasoline, or the like. In this embodiment, the hydrocarbon fuel source (8020) includes a liquid fuel container that can be pressurized and a vaporizer or atomizer module disposed between the liquid fuel container and a mixing chamber (8105). The liquid fuel is delivered to a vaporizer or atomizer configured to convert the liquid fuel into a hydrocarbon gas vapor or a mist containing liquid fuel droplets. Hydrocarbon gas vapor or mist is delivered to a hydrocarbon fuel input conduit (8022) for delivery to a mixing chamber (8015). In this embodiment, the vaporizer or atomizer is operated as a hydrocarbon fuel flow modulator (8035) when the vaporizer or atomizer includes an electromechanical actuator or the like that is controllable in communication with an electronic controller (190). Good too. The controllable electromechanical actuator moves or otherwise manipulates elements associated with vaporizing or atomizing the liquid fuel supply to adjust the flow rate of the hydrocarbon fuel into the mixing chamber (8015). It works like this.

In a further non-limiting embodiment, the vaporizer or atomizer delivers a liquid hydrocarbon fuel mist or vapor from the liquid fuel source to the liquid hydrocarbon fuel input conduit (8022) at a substantially constant hydrocarbon fuel flow rate. , the regulation of the hydrocarbon fuel flow rate is performed by a gas flow control valve described below.

Gas Flow Control Valves In further non-limiting, exemplary embodiments, one or both of the oxidant flow modulator (8025) and the hydrocarbon fuel flow modulator (8035) are connected to the corresponding input conduits (8017, 8022). ) along with a gas flow control valve disposed between the corresponding oxidant source (8010) or hydrocarbon fuel source (8020) and the mixing chamber (8015). Each gas flow valve includes an electromechanical actuator in communication with an electronic controller (190). The electromechanical actuator operates to rotate or move a movable gate or the like, the movable gate being disposed inside the gas flow control valve or inside the corresponding input conduit (8017, 8022). The movable gates are moved in response to control and command signals received from the electronic controller (190) to direct each of the oxidizer and hydrocarbon fuel through the gas control valve and into the mixing chamber (8015). Adjust the flow rate independently. Accordingly, each of the gas flow valves operating as either an oxidizer flow modulator (8025) or a fuel flow modulator (8035) is operated by an electronic controller (190) that controls the flow of fluid passing through the movable gate. The fluid flow rate is configured to adjust the flow rate so that the fluid flow rate ranges between substantially zero oxidant or hydrocarbon fuel flow rate and a maximum oxidant or hydrocarbon fuel flow rate. Preferably, the gas flow valve is operable to provide a plurality of discreet incremental volume flow levels over a flow range, each incremental volume flow level being approximately 0.1 to 1.0 standard cubic centimeters per minute (SCCM). ) change the flow rate.

Cathode Air Pump The fuel cell stack includes a cathode air input port (2205) that communicates with the cathode chamber (2010), shown in FIG. A source of cathode air or other oxidant (8045) is arranged to deliver a stream of cathode air or other oxidant to a cathode air input conduit (8055) leading to the air input port (2205). A cathode air flow modulator (8050) is disposed along the cathode air input conduit (8055) between the cathode air source (8045) and the cathode air input port (2205). The cathode air flow modulator (8050) includes at least one controllable electromechanical actuator (not shown) that is controlled by an electronic controller (190). In one exemplary embodiment, the cathode air source (8045) is an air pump or fan that also operates as a cathode flow modulator (8050). In this example, the air pump or fan includes a controllable electromechanical actuator in communication with an electronic controller (190). The controllable electromechanical actuator operates to rotate or otherwise move a controllable air moving device, such as a pump vane, fan blade, etc. associated with an air pump or fan, at different speeds. Movement of the air moving device directs or draws cathode air into the cathode air input conduit (8055), and the volumetric flow rate of the cathode air changes the angular velocity of the pump vanes or fan blades by changing the speed of the air moving device, for example. It changes depending on what you do. Changes in speed of the air moving device are driven by control and command signals received from the electronic controller (190). The command and control signals vary the speed of the air moving device to adjust the volumetric flow rate of cathode air through the cathode air input conduit (8055) to the cathode air input port (2205). Accordingly, an air pump or fan operating as a cathode flow modulator (8050) is operated by an electronic controller (190) that operates between substantially zero cathode air flow and maximum cathode air flow. , configured to adjust the volumetric fluid flow rate of cathode air passing through the cathode air input conduit (8055) to the cathode air input port (2205). Preferably, the air moving device used to adjust the cathode air volumetric flow rate provides a plurality of discreet incremental volumetric flow levels over a volumetric flow range, each incremental volumetric flow level being about 0.5 to 2. Varying flow rate of .0 standard cubic centimeters per minute (SCCM).

As mentioned above, with respect to the oxidant source (8010), the cathode air source (8045) may include a compressed gas container, such as a pressurized oxygen or air tank, including a passive pressure regulator. Alternatively, the cathode supply source (8045) may include an air pump or fan or the like that draws air into the cathode air input conduit (8055) from the ambient environment or from a ventilation conduit or the like. However, the air pump or fan does not operate as a cathode air flow modulator (8050). Instead, the flow rate of cathode air delivered to the cathode air conduit (8055) by the air pump or fan is substantially constant when the air pump or fan speed is not adjusted by the electronic controller. In this embodiment, fuel flow regulation is provided by a gas flow control valve disposed along the fuel input conduit (8022), as described above.

Fuel Air Mixture The mixing chamber (8015) is preferably a helical chamber used to mix the hydrocarbon fuel stream and the oxidant stream to produce the fuel air mixture (2025, 3025). The fuel air mixture preferably has an oxygen to carbon (O:C) ratio in the range 1.0 to 2.2, where the O:C ratio corresponds to a molar ratio, e.g. do.

The fuel-air mixture (2025, 3025) exits from the mixing chamber (8015) into a gas flow conduit (2045, 7045), which exits from the fuel/oxidizer input control module (8005). It extends into a fuel chamber (3005) and is formed within the fuel chamber system (3000) shown in FIGS. 3, 4, 4A, and 7 and described above. The preferred hydrocarbon fuel of the present disclosure is methane ( _CH4 ), but other longer hydrocarbon molecular chains including ethane _{( C2H6 )} propane ( _C3H8 ), butane ( _C4H10 ), _etc. can be used. Additionally, liquid hydrocarbon fuels having hydrocarbon chains ranging from C ₅ H ₁₂ to C ₁₈ H ₃₂ can be reformed by the systems and methods of the present disclosure.

CPOX Reaction The fuel furnace system (3000) is configured to reform the fuel air mixture (2025, 3025) by catalytic partial oxidation (CPOX). The CPOX reaction is an exothermic reaction (flameless combustion) that converts the fuel-air mixture into synthesis gas (2027). Synthesis gas (2027) is a reformate containing anode gas used to react with the solid oxide anode electrode surface formed on the inner surface of each tubular fuel cell (2080) of the SOFC stack (135, 2005). It is. The anode gas reactants are _H2 and CO because both reactants can combine with the available oxygen atoms on the solid oxide anode electrode surface. of the tubular fuel cell (2080) by the combination of available oxygen atoms or ions on the anode electrode surface with the _H2 reactant to form _H2O and the combination with the CO reactant to form _CO2 . Each generates a DC current that is output to the DC power module (140) shown in FIG. In an alternative embodiment, the CPOX reactor and fuel reforming method of the present disclosure can be used to deliver syngas to a planar solid oxide anode electrode surface without departing from this disclosure.

The oxygen atoms or ions available on the solid oxide anode electrode surface are received from oxygen gas O ₂ available from the cathode air pumped into the cathode chamber (2010). The input volumetric flow rate of cathode air is adjusted to keep up with the demand for oxygen atoms or ions on the solid anode electrode surface. Oxygen gas from the cathode air reacts with the solid oxide cathode electrode surface (155) and is formed on the outer surface of each tubular fuel cell (2080) or on the flat solid oxide cathode electrode surface. be done. Oxygen gas _O2 is separated into individual oxygen atoms or ions that pass through a solid oxide cathode electrode, pass through an electrolyte layer disposed between the cathode and anode electrodes, and pass through the solid oxide, which is exposed to the anode gas. Pass through the oxide anode electrode.

Equation 6, shown below, details the CPOX chemistry associated with converting the fuel-air mixture to syngas (2027). The CPOX chemical reaction of Equation 6 is initiated when the fuel-air mixture contacts the catalyst layer (3090) coated on the inner surface of the catalytic fuel passage. The catalyst layer (3090) initiates the CPOX chemical reaction at a CPOX reaction temperature of 600-900°C. Without the catalyst layer (3090), the CPOX reaction temperature would be 1000-1200°C.

C _n H _m + (n/2)O ₂ →nCO + m/2H ₂ equivalent 6

Based on Equation 6, when the hydrocarbon fuel is methane (CH ₄ ), the fuel-air mixture has an O:C ratio equal to 1.0 and a CO:H ₂ power ratio of 0.5. When the hydrocarbon fuel is ethane (C ₂ H ₆ ), the fuel-air mixture has an O:C ratio equal to 1.0 and a CO:H ₂ power ratio of 0.66. When the hydrocarbon fuel is propane (C ₃ H ₈ ), the fuel-air mixture has an O:C ratio equal to 1.0 and a CO:H ₂ power ratio of 0.75.

However, in Equation 6, the air is replaced by an oxidizer instead of pure oxygen or to use a heterogeneous hydrocarbon fuel source containing a mixture of hydrocarbon molecules of different chain lengths and/or other contaminants. There is no explanation of how to use it as. Furthermore, Equation 6 assumes precise molar ratios of the reactants, which is difficult to achieve in practice. Without the correct molar ratio of fuel-air mixture, the syngas reaction can be incomplete. In one example, if the fuel-air mixture has a low O:C ratio, e.g. less than 1.0, i.e., there are more hydrocarbon fuel molecules than available oxygen molecules to react, the synthesis gas will contain unreacted hydrocarbons. It may contain fuel molecules CnHm. When this occurs, unreacted hydrocarbon fuel is flushed from the fuel cell without producing any electrical power. In the other case, when the fuel-air mixture has a high O:C ratio above 1.0, i.e. when there are more oxygen molecules than hydrocarbon fuel molecules, the synthesis gas combines with the H ₂ and CO components of the synthesis gas. The anode gas may contain excess oxygen gas (O ₂ ), which reduces the available anode gas reactants to contribute to the power generated. Therefore, an important aspect of the present disclosure is to balance the components of the fuel-air mixture of Equation 6 from syngas that can react to form methane to unreacted hydrocarbon fuel, such as free carbon atoms and excess oxygen gas. ( _CH4 ). As explained below, the present disclosure uses removed methane from the syngas formed by the CPOX reaction as a control indicator to establish the desired O:C ratio.

Other known problems associated with CPOX chemistry include coke formation and undesirable reactions due to fuel contamination. Coke formation occurs when carbon molecules combine with the surface of the catalyst layer (3090) during the CPOX reaction. Carbon molecules contained in the syngas output can also contaminate the surface of the solid oxide anode electrode layer (150), reducing the efficiency of the anode electrode layer. In both cases, coke formation tends to reduce the overall efficiency of the SOFC system. Also, as mentioned above, a low O:C ratio can further contribute to unreacted hydrocarbon atoms and/or free carbon atoms that can contribute to coke formation.

Coke formation is temperature dependent and tends to be more thermodynamically favorable at CPOX reaction temperatures below about 800°C. Therefore, it is important to maintain a minimum CPOX reaction temperature above about 800°C, preferably about 850-950°C, to avoid coke formation. As mentioned above, the maximum CPOX reaction temperature occurs proximate the interface (3032) where the incoming fuel-air mixture makes initial contact with the catalyst layer. However, a portion of the fuel-air mixture will likely have initial contact with the catalyst layer more distal to the interfacial layer (3032) and react at a CPOX reaction temperature that is lower than the CPOX reaction temperature at the interface. Therefore, maintaining a minimum CPOX reaction temperature of approximately 800°C proximal to the interface (3032) does not necessarily eliminate coke formation distal to the interface (3032), where the reaction temperature may be less than 800°C. Not exclusively. Coke formation is also stimulated by low O:C ratios, e.g. less than 1.0, but when the oxidizer is air, the actual O:C ratio of the fuel/air mixture exiting the mixing chamber is somewhat poor. To be certain, it is desirable to provide another indicator, such as the lack or minimization of methane in the syngas, as an indication that the desired O:C ratio is being provided.

A CPOX reaction control method is discussed and addressed in US Pat. No. 8,337,757 by Roychoubhury et al. entitled Nuclear Reactor Control Method. Roychoubhury et al. disclose a CPOX reactor control method that includes periodically measuring the CPOX reaction temperature at three separate locations in the CPOX reactor. A nuclear reactor control method includes selecting a steady state operating temperature and a maximum safe operating temperature. Based on the measured CPOX reaction temperatures at each of three separate locations, the reactor control method determines the maximum temperature, the minimum temperature, and the difference between the maximum and minimum temperatures. The reactor control method then changes the O:C ratio of the incoming fuel-air mixture in a manner that prevents the maximum temperature from exceeding the maximum safe operating temperature while minimizing the difference between the maximum and minimum temperatures. Change three control parameters. The three control parameters that are changed to effectively change the O:C ratio are changing only the fuel input flow rate, changing only the air input flow rate, and changing the fuel input flow rate and the air input flow rate. Including alternating changes.

Roychoubhury et al. disclose a CPOX reactor control method that addresses the need to vary the O:C ratio to minimize the difference between the highest and lowest temperatures of three separate locations in the CPOX reactor; One problem with the control method disclosed by Roychoubhury et al. is that it requires three different thermal sensors to be placed, one at each of three separate locations within the reactor. Another problem with the CPOX reactor control method disclosed by Roychoubhury et al. is that changes in the O:C ratio used to change the CPOX reaction temperature may affect the overall power conversion of the SOFC system relative to the SOFC reaction temperature. This does not take into consideration the possibility that it may have an adverse effect to the extent that efficiency may be impaired. Specifically, using CPOX reaction temperature alone as an indicator of the desired O:C ratio can compromise system power conversion. Fuel contaminants such as tar (C ₁₀ H ₈ ) and other long chain hydrocarbon molecules can contribute to coke formation. Sulfur is a fuel contaminant that forms sulfides either in the fuel/air mixture or in the syngas. Sulfides, including carbon disulfide (CS ₂ ), hydrogen sulfide (H ₂ S), sulfur dioxide (SO ₂ ), etc., can poison the catalyst layer in CPOX reactors as well as in SOFC stacks. There is a possibility of competing for oxygen sites in the solid oxide anode electrode layer (150). Therefore, it is desirable that the hydrocarbon fuel source have a low sulfur content, eg, less than about 50 parts per million (PPM). Another problem that reduces CPOX conversion efficiency is catalyst layer burn-through, which occurs when sections or catalyst layers are permanently damaged by prolonged exposure to excessive reaction temperatures. Therefore, it is important that the CPOX reaction temperature does not exceed the melt-through temperature.

Despite the complexities of syngas generation, when air is used as the oxidant, syngas consists primarily of major parts N ₂ , H ₂ , and various proportions, with a small proportion of CO ₂ . Contains CO. However, the weight percentages of each of the syngas components, including the weight percentages of the reactants _H2 and CO, vary depending on changes in the O:C ratio, changes in the CPOX reaction temperature, changes in the type of hydrocarbon fuel, and the homogeneity of the hydrocarbon fuel. changes in nature and contaminant content. Thus, syngas may contain minor proportions of other components such as unreacted hydrocarbons, oxygen gas, sulfides, water, and the weight percent of each major proportion of the syngas components is O: It changes with changes in C ratio as well as changes in CPOX reaction temperature.

Accordingly, an objective of one aspect of the present disclosure is to maximize the conversion efficiency of the CPOX reaction by maximizing the weight percent of the anode gas reactants _H2 and CO, while The weight percent of unreacted hydrocarbons (eg, methane (CH ₄ ) and oxygen gas (O ₂ )) in the syngas is also minimized.

8.12.8 First Thermal Sensor and Thermal Conductive Coupling Referring now to FIGS. A number of different non-limiting exemplary embodiments of the attached first thermal sensor (8030) are shown. In each of the non-limiting exemplary embodiments, the corresponding heat transfer element is supported in mating contact with the longitudinal surface of the cylindrical catalyst body (3030) and has a heat transfer coefficient of 50 W/m°K or greater; Preferably, it is formed from a material having a thermal conductivity coefficient of 100 W/m°K or more. This compares to the thermal conductivity of ceramic catalyst bodies of about 2-7 W/m°K. Additionally, each of the heat transfer elements has a contact area between the heat transfer element and the catalyst body sufficient to promote a high conductive thermal energy transfer rate from the catalyst body (3030) to the heat transfer element across the contact area. It is formed accordingly. If the temperature difference between the catalyst body and the heat transfer element is large, for example during initial start-up, the thermal conductivity across the contact zone is large. However, as the temperature difference approaches zero, the largest influence on the thermal conductivity between the catalytic body and the heat transfer element is the thermal conductivity of the heat transfer element, the contact area between the heat transfer element and the catalytic body, and the is the thermal mass of the heat transfer element (see equation 5 above). However, for materials with high thermal conductivity coefficients, such as copper and aluminum, which are mainly metals, the difference in thermal mass is more simply expressed as the difference in material volume. Therefore, apart from selecting a material with a high heat transfer coefficient, the heat transfer element of the present disclosure is formed with sufficient contact area between the catalyst body and the heat transfer element, and the catalyst body ( 3030) with a volume of material to rapidly transfer thermal energy from the heat transfer element to the heat transfer element. Preferably, the contact surface area is sized to promote sufficiently high thermal conductivity between the catalyst body and the heat transfer element such that the temperature of the contact zone surface is substantially matched by the temperature of the heat transfer element. be done.

Each heat transfer element is supported in mating contact with either the outer or inner longitudinal surface of the cylindrical catalyst body (3030). The contact area between the catalyst body and the heat transfer element is defined as the product of the circumferential contact area and the longitudinal contact area, where the longitudinal contact area extends along the longitudinal axis of the catalyst body and the circumferential contact area The directional contact zone extends along the circumferential surface of the catalyst body orthogonal to the longitudinal axis. Other contact area shapes and orientations can be used without departing from this disclosure.

When formed with sufficient thermal mass and contact area, the heat transfer element will maintain its temperature across the contact area until the temperature of the heat transfer element is substantially equal to the average or bulk surface temperature of the catalyst body over the contact surface area. Configured to rapidly transfer thermal energy. Furthermore, due to the high thermal conductivity provided over the contact surface area, a change in the bulk or average temperature of the contact surface area of the catalyst body is rapidly followed by a similar change in the temperature of the heat transfer element. The temperature sensed by the first thermal sensor (8030) thus provides a reliable and repeatable indication of the average or bulk surface temperature of the catalyst body over the contact zone.

The first thermal sensor (8030) is connected to an electronic controller at a sampling frequency that generates a continuous stream of first temperature signal values each corresponding to an instantaneous temperature as a surface of the heat transfer element to which the first thermal sensor is attached. A first temperature signal (8031) is generated which is sampled by. The temperature sensed by the first thermal sensor (8030) provides a reliable and repeatable indication of the average or bulk surface temperature of the catalyst body over the contact zone, and thus the first temperature signal (8031). The change corresponds, for example, to a proportional change in the CPOX reaction temperature as the O:C ratio of the incoming fuel changes. Viewed another way, the change in the first temperature signal (8031) is proportional to the change in heat flux density (W/m ² ) carried out thermally across the contact area.

As mentioned above, the temperature of the CPOX reaction is likely to vary along the longitudinal length of the cylindrical catalyst body. According to a conventional nuclear reactor control method disclosed by Roychoubhury et al., three temperature sensors are placed at three separate longitudinal locations to sense three different temperatures along the longitudinal length of the catalyst body. will be placed in The algorithm determines the maximum and minimum temperatures corresponding to the temperatures output by the three sensors, and based on the temperature distribution, the O:C ratio of the incoming fuel-air mixture is determined by the maximum and minimum temperatures sensed by the three temperature sensors. Changes in a manner that minimizes temperature differences. However, the present disclosure provides only one temperature sensor coupled with a heat transfer element supported in contact with the catalyst body over the contact area, extending along a portion of the longitudinal dimension of the catalyst body. use. By sensing only the first temperature signal (8031), the present disclosure reduces complexity and improves reliability by reducing the number of sensors and eliminating algorithms for calculating temperature spread. let The thermally conductive elements of any of the embodiments shown in FIGS. 9-12 and 13A and 13B may be any of copper, aluminum, nickel, brass, beryllium, iridium, magnesium, molybdenum, tungsten and zinc and/or alloys thereof. or one. Additionally, for materials susceptible to oxidative damage at operating temperatures above about 400° C., the external surface of the thermally conductive element is coated with an oxidation-resistant material, such as nickel plating, for example.

Referring to FIG. 9 in a first exemplary non-limiting embodiment, the first heat transfer element includes a prismatic rod ( 9005). The longitudinal axis (9015) of the prism rod (9005) is oriented substantially parallel to the longitudinal axis (9020) of the catalyst body (3030). The catalyst body (3030) is a cylindrical element comprising a ceramic substrate with a diameter of 25.4 mm and a longitudinal length of 25.4 mm. When installed in the cylindrical catalyst cavity (3035), the catalyst body (3030) has an input end at the interface (3032) and syngas (2027) into the fuel inlet manifold (3055), as shown in FIG. It has an output end (3034) for delivering.

The prismatic rod (9005) of the first heat transfer element has a diameter of 3.2 mm, which is approximately one-eighth (1/8) of the diameter of the catalyst body (3030). The prism rod (9005) has a longitudinal length of 6.3 to 12.7 mm, which is about one quarter (1/4) to half the longitudinal length of the catalyst body (3030). 1 (1/2). The prism rod (9005) extends longitudinally so as to contact the outer surface (9010) of the catalyst body (3030) at any longitudinal position between the input or interface end (3032) and the output end (3034). can be positioned in the direction. The optimal longitudinal contact position of the prism rod (9005) may be determined experimentally, for example during system calibration, or a support provided to support the prism rod (9005) in mating contact with the contact surface. It may also be determined by the structure, etc. Other prism rods (9005) having different longitudinal and outer diameter dimensions can be used without departing from this disclosure.

A first thermal sensor (8030) is attached to or supported by the prism rod (9005) between at least one surface of the prism rod (9005) and the first thermal sensor (8030). Provides a thermally conductive bond. In the exemplary embodiment of FIG. 9, the prism rod (9005) includes a through hole or blind hole (9025) extending along the longitudinal axis (9015) of the prism rod. A first thermal sensor (8030) is installed in the through or blind hole (9025) and held in place. Alternatively, the first thermal sensor (8030) can be thermally attached to any external or internal surface of the prism rod (9005) by brazing with a thermally conductive adhesive, such as by one or more mechanical fasteners or clamps. conductively coupled.

The prismatic rod (9005) is attached to or engaged with the outer surface (9010) of the catalyst body (3030) by means of radially internal pressure exerted by an insulating element (3080) disposed inside the catalyst cavity (3035). They are supported in contact with each other. As best shown in FIG. 3, the insulation element (3080) is an annular ring disposed inside the catalyst cavity (3035) between the annular enclosure wall (3060) and the cylindrical catalyst body (3030). is formed as. The insulation element (3080) is installed by installing a prism rod (9005) and a first thermal sensor (8030) in the catalyst cavity (3035) between the insulation element (3080) and the outer surface of the catalyst body (3030). , providing sufficient radially directed compressive force to support the prism rod (9005) in mating contact with the cylindrical catalyst body (3030). The compressive force is sufficient to thermally conductively couple the prismatic rod with the cylindrical catalyst body (3030) over the contact area. Alternatively, prism rod (9005) is coupled to the outer surface of catalyst body (3030), such as by brazing, a thermally conductive adhesive, one or more fasteners or clamps, or the like. Preferably, the configuration of the prismatic rod (9005), the configuration of the first thermal sensor (8030), the longitudinal position between the interface (3032) and the output end (3034), and the configuration of the prismatic rod relative to the outer surface of the catalyst body are preferred. The contact method used to secure the rod (9005) is primarily sensitive to temperature changes in the bulk or average temperature of the contact area associated with changes in the flow rate of oxidant delivered to the mixing chamber (8015). A first temperature signal output from a first thermal sensor (8030) is provided that is repeatable and fully responsive.

Referring now to FIG. 10, the second thermally conductive element embodiment (10010) includes a cylindrical segment (10005). The cylindrical segment (10005) includes a contact surface area (10008) formed with a radius of curvature that matches the radius of curvature of the outer circumferential surface of the cylindrical catalyst body (3030). The cylindrical segment (10005) includes a longitudinal axis (10015) oriented parallel to the longitudinal axis (10020) of the cylindrical catalyst body (3030). The cylindrical segment (10005) is formed from a prismatic rod having a diameter of approximately 6.4 mm, which is approximately one-quarter (1/4) of the diameter of the cylindrical catalyst body (3030). The cylindrical segment (10005) has a longitudinal length of 6.3 to 12.7 mm, which is approximately one-fourth (1/4) to 2 of the longitudinal length dimension of the catalyst body (3030). It is one-half (1/2). The cylindrical segment (10005) is longitudinally configured to contact the outer surface (10010) of the catalyst body (3030) at any longitudinal location between the input or interface end (3032) and the output end (3034). can be positioned at Other cylindrical segments (10005) having other rod diameters and longitudinal length dimensions can be used without departing from this disclosure.

A first thermal sensor (8030) is attached to or supported by the cylindrical segment (10005) and generates a first temperature signal corresponding to the temperature of the cylindrical segment (10005) proximate a surface in contact therewith. (8031) is provided. In the exemplary embodiment of FIG. 10, the cylindrical segment (10005) includes a through hole or blind hole (10025) extending along its longitudinal axis (10015), and the first thermal sensor (8030) Installed in a hole or blind hole (10025). Alternatively, the first thermal sensor (8030) can be thermally conductive by brazing to any external or internal surface of the cylindrical segment (10005) with a thermally conductive adhesive, such as by one or more fasteners of a clamp. are combined.

The cylindrical segment (10005) is attached to or engaged with the outer surface (10010) of the catalyst body (3030) by means of radially internal pressure exerted by an insulating element (3080) disposed inside the catalyst cavity (3035). They are supported in contact with each other. As best shown in FIG. 3, the insulation element (3080) is an annular ring disposed inside the catalyst cavity (3035) between the annular enclosure wall (3060) and the cylindrical catalyst body (3030). is formed as. An insulating element (3080) is provided between the insulating element (3080) and the outer surface of the catalyst body (3030) by attaching a cylindrical segment (10005) and a first thermal sensor (8030) to the catalyst cavity (3035). provides sufficient radial compressive force to support the cylindrical segment (10005) in mating contact with the cylindrical catalyst body (3030). The compressive force is sufficient to thermally conductively couple the cylindrical segment (10005) with the cylindrical catalyst body (3030) over the entire surface contact area (10008). Alternatively, cylindrical segment (10005) is coupled to the outer surface of catalyst body (3030), such as by brazing, thermally conductive adhesive, one or more fasteners or clamps, or the like. Preferably, the configuration of the cylindrical segment (10005), the configuration of the first thermal sensor (8030), the longitudinal position between the interface (3032) and the output end (3034), and the outer surface of the catalyst body The contact method used to secure the cylindrical segment (10005) primarily depends on temperature changes in the bulk of the contact area, or the average temperature associated with changes in the flow rate of oxidant delivered to the mixing chamber (8015). In contrast, providing a repeatable and fully responsive first temperature signal output from the first thermal sensor (8030).

Referring now to FIG. 11, in a third exemplary non-limiting embodiment, the third heat transfer element is sized to provide mating contact with the outer diameter of the catalyst body (3030). a hollow cylinder (11005) having an inner diameter and an outer diameter sized to provide the desired thickness or material volume of the annular wall formed by the hollow cylinder (11005). The hollow cylinder (11005) has a longitudinal axis (11015) oriented substantially coaxially with the longitudinal axis (11020) of the catalyst body (3030). The contact area between the hollow cylinder (11005) and the catalyst body (3030) extends above the surface of the inner diameter of the hollow cylinder (11005).

The hollow cylinder (11005) has an annular wall thickness of about 1.6 mm and about one-fourth (1/4) to one-half (1/2) of the longitudinal length of the catalyst body (3030). It is formed with a longitudinal length of 6.3 to 12.7 mm. The hollow cylinder (11005) is longitudinally positioned to contact the outer surface (10010) of the catalyst body (3030) at any longitudinal position between the input and output ends (3034) of the interface end (3032). may be done. The hollow cylinder (11005) is held in mating contact with the outer surface (11010) of the catalyst body (3030), such as by soldering, by a thermally conductive adhesive, by crimping, by fasteners or clamps, by an interference fit, etc. be done. Other hollow cylinders (11005) having different longitudinal lengths or material thicknesses can be used without departing from this disclosure.

A first thermal sensor (8030) is attached to the outer surface of the hollow cylinder (11005) to provide a thermally conductive coupling between the outer surface of the hollow cylinder (11005) and the first thermal sensor (8030). or alternatively supported in mating contact therewith. In the exemplary embodiment of FIG. 11, the first thermal sensor (8030) is applied by a thermal insulation element (3080) disposed inside the catalyst cavity (3035), as shown in FIG. 3 and described above. in mating contact with the outer surface of the hollow cylinder (11005) by one of the following: by brazing, by a thermally conductive adhesive, by one or more fasteners or clamps, etc. thermally conductively coupled or supported.

Referring now to FIG. 12, a fourth exemplary non-limiting conductive element embodiment includes a hollow cylinder helical portion (12005). The helical portion (12005) has an inner radius sized to provide mating contact with the outer surface (12010) of the catalyst body (3030) and a desired thickness of the helical portion (12005). and an outer radius sized to. The helical portion has a longitudinal axis (12015) oriented substantially coaxially with the longitudinal axis (12020) of the catalyst body (3030).

The helical portion (12005) has an annular wall thickness of about 1.6 mm and a longitudinal length of 12.7 to 25.4 mm, or about one-half (1/2) of the total longitudinal length of the catalyst body (3030). ) is formed with The helical portion (12005) is longitudinally positioned to contact the outer surface (11010) of the catalyst body (3030) at any longitudinal location between the interface end (3032) and the output end (3034). can be done. Other helical portions (12005) having different longitudinal length and thickness dimensions can be used without departing from this disclosure.

A first thermal sensor (8030) is attached to or supported in mating contact with the outer surface of the helical portion (12005), with a thermal Provides conductive coupling. In the exemplary embodiment of FIG. 12, the first thermal sensor (8030) is applied by a thermal insulation element (3080) disposed inside the catalyst cavity (3035), as shown in FIG. 3 and described above. Heat is applied in mating contact with the outer surface of the helical portion (12005) by one of the following: by an inward radial pressure of the helical portion (12005), by brazing, by a thermally conductive adhesive, by one or more fasteners or clamps, etc. conductively coupled or supported.

Referring now to FIGS. 13A and 13B, cylindrical catalyst body (13030) includes a plurality of catalytic fuel passages (3085) each providing an individual conduit extending longitudinally through cylindrical catalyst body (13030). The central cavity (13007) is formed by a through or blind hole extending completely or partially through the cylindrical catalyst body (13030) along its longitudinal axis (13020). As shown in the cross-sectional view of FIG. 13B, a fifth exemplary non-limiting conductive element embodiment includes a solid cylinder (13005) disposed inside a central cavity (13007). A solid cylinder (13005) is supported within and in mating contact with the inner diameter of the central cavity (13007). The solid cylinder (13005) has a longitudinal axis that extends substantially coaxially with the longitudinal axis (13020) of the catalyst body (13030).

A solid cylinder (13005) is formed with an outer diameter sized equal to, slightly larger, or slightly smaller than the inner diameter of the central cavity (13007). A non-limiting example diameter of the solid cylinder (13005) is a diameter of 1.5-6.4 mm with a longitudinal length of 6.3-12.7 mm, which is equal to the longitudinal length of the catalyst body (13030). It is approximately one-fourth (1/4) to one-half (1/2) of the length. The solid cylinder (13005) may be longitudinally positioned to contact the central cavity (13007) at any longitudinal location between the input or interface end (3032) and the output end (3034). Other solid cylinder (13005) embodiments having different longitudinal lengths and outer cylinder diameter dimensions can be used without departing from this disclosure.

A first thermal sensor (8030) is attached to the solid cylinder (13005) or provides a thermally conductive coupling between at least one surface of the solid cylinder (13005) and the first thermal sensor (8030). do. In the exemplary embodiment of FIG. 13B, the solid cylinder (13005) includes a through hole or blind hole (13025) that extends along or parallel to the longitudinal axis (13020) of the solid cylinder (13005). A first thermal sensor (8030) is installed in the through or blind hole (13025) and held in place. Alternatively, the first thermal sensor (8030) can be attached to any external or internal surface of the solid cylinder (13005) by brazing, such as with a thermally conductive adhesive or one or more mechanical fasteners or clamps. thermally conductively coupled.

Referring to FIG. 14 in a sixth exemplary non-limiting embodiment, a solid, non-porous, ceramic foam formed with a plurality of interconnected open cells distributed throughout the solid ceramic foam structure. A cylindrical catalyst body (14030) formed as an open cell solid foam structure containing material is provided. The open cell extends between the input or interface end (3032) and the output end (3034). However, some open cells may extend from the input or interface end (3032) to the sidewall of the cylindrical catalyst body (14030). Each of the plurality of open cells (14031) includes its inner surface coated with a catalyst layer (3090). The open cell solid foam structure is formed as a cylindrical catalyst body (14030) with a circumferential diameter of 25.4 mm and a longitudinal length of 25.4 mm. Once installed in the cylindrical catalyst cavity (3035), the input end (14032) of the cylindrical catalyst body (14030) is inserted and contacts the reactor shield base wall (3015) at the interface (3032) and the reactor The fuel-air mixture (2025, 3025) exiting the shield base wall (3015) enters the input end of the solid foam structure through its open cells (14031) and passes through the open cells to the output end (14034) or the circumferential outer surface (14010). ) through an open cell opening. While passing through the open cell, the fuel air mixture (2025, 3025) contacts the catalyst layer (3090) to initiate the CPOX reaction. After exiting the open cell, the reformate or syngas (2027) passes from the catalyst cavity to the fuel inlet manifold (3055).

Prism rods (9005) can be used as heat transfer elements. As mentioned above, prism rod (9005) has a diameter of 3.2 mm, which is approximately one-eighth (1/8) of the diameter of cylindrical catalyst body (14030), and It has a longitudinal length of 6.3 to 12.7 mm, which is about one-quarter (1/4) to one-half (1/2) of the longitudinal length. Prism rod (9005) may be longitudinally positioned to contact circumferential outer surface (14010) at any longitudinal location between interface end (13032) and output end (13034). Similarly, any of the heat transfer elements described above (10005, 11005, 12005, 13005) can be used in combination with the open cell solid foam structure of the catalyst body (14030).

A first thermal sensor (8030) is attached to or supported by the prism rod (9005) between at least one surface of the prism rod (9005) and the first thermal sensor (8030). Provides a thermally conductive bond. In the exemplary embodiment of FIG. 14, the prism rod (9005) includes a through hole or a blind hole (9025) extending along its longitudinal axis (9015), and the first thermal sensor (8030) Or installed in a blind hole (9025). Alternatively, the first thermal sensor (8030) can be thermally conductively attached to any external or internal surface of the prism rod (9005), such as by brazing, by thermally conductive adhesive, by fasteners in one or more clamps, etc. is combined with

The prism rod (9005) is thermally conductive by radial pressure applied by an insulating element (3080) disposed inside the catalyst cavity (3035) or by brazing, as shown in FIG. 3 and described above. attached or supported by mating contact with the circumferential outer surface (14010) of the cylindrical catalyst body (14030), such as by a adhesive or one of one or more fasteners or clamps; .

Second Thermal Sensor Referring now to FIG. 8, the second thermal sensor (8040) is located on the outer surface of one of the hot zone enclosure walls (115), such as the longitudinal cylindrical side wall shown in FIG. (2015) is thermally conductively coupled to the outer surface of the (2015). Alternatively, the second thermal sensor (8040) can be positioned on the inner or outer surface of any one of the hot zone enclosure walls forming the first heat transfer path. A second thermal sensor (8040) generates second temperature signals sampled by the electronic controller at a sampling frequency, each corresponding to an instantaneous temperature of a surface of one of the hot zone enclosure walls (115). A continuous stream of second temperature signal values is generated. However, because the hot zone enclosure wall (115) is thermally conductively coupled to the disc-shaped support walls (2082, 2084) that support opposite ends of each tubular fuel cell (2080) of the SOFC stack, the The change in temperature represented by the change in the temperature signal of 2 corresponds to or is proportional to the change in SOFC reaction temperature, for example, when the O:C ratio of the incoming fuel changes. Alternatively, in other non-limiting embodiments, the second thermal sensor (8040) detects that the change in temperature represented by the change in the second temperature signal causes, for example, a change in the O:C ratio of the incoming fuel. At times, any surface of the intermediate enclosure (2510) that forms the second heat transfer path, or the third heat transfer path, as long as it is responsive to or proportional to a change in SOFC reaction temperature, may be removed from the present disclosure. It is thermally conductively coupled to any one of the outer enclosure walls (2514, 2516, 2518) forming a non-deviating form.

Third thermal sensor:
Referring now to FIG. 3, a third thermal sensor (3135) is thermally conductively coupled to a surface of the heat sink flange 3100 shown in FIG. Alternatively, the third thermal sensor (3135) is located on any surface of the fuel reactor body (3040) that extends outside of the outer enclosure wall (2514, 2516, 2518) forming a third heat transfer path. Can be positioned. A third thermal sensor (3135) generates a continuous stream of third temperature signal values each corresponding to an instantaneous temperature corresponding to a surface of a third heat transfer path associated with a surface of the fuel reactor body (3040). A third temperature signal is generated which is sampled by the electronic controller at a sampling frequency of . However, because the third heat conduction path also extends to elements that do not extend outside the outer enclosure wall, such as the annular peripheral wall (3010) and the reactor shield base wall (3015), the third temperature The change in the signal ideally corresponds to a temperature change in the fuel reactor body as the temperature inside the fuel chamber approaches the fuel auto-ignition temperature, which ranges from 295 to 580 degrees Celsius, depending on the type of hydrocarbon fuel, for example. , or proportionally.
Alternative operating mode CPOX reaction temperature

Referring now to FIG. 8, in a non-limiting exemplary mode of operation, a first temperature signal (8031) is received by the electronic controller (190) from the first thermal sensor (8030). The first temperature signal (8030) may include analog or digital signals corresponding to voltage or current amplitudes, normalized voltage or current amplitudes, etc., such that each of the first temperature signals (8031) has a different voltage or The current amplitude value corresponds to the actual instantaneous temperature or the relative instantaneous temperature sensed by the first thermal sensor (8030). The electronic controller (190) stores a plurality of first temperature set point values. The plurality of first temperature set point values may include different first temperature set point values for each type of hydrocarbon fuel used by the SOFC system _, e.g., a first temperature set point value for propane ( _C3H8 ). and different first temperature set points for natural gas or methane ( _CH4 ), and the like. The plurality of first temperature set point values may include different first temperature set point values for each operating mode of the SOFC system, e.g., a first temperature set point value associated with a startup mode when the fuel is propane; and a different first temperature set point value associated with a steady state operating mode when the fuel is propane. The plurality of first temperature set point values may also include a first temperature set point value associated with a maximum safe operating temperature, for example when the fuel is methane or the like. In addition, each first temperature set point value includes a range of values, e.g., defined by a maximum and minimum first temperature set point value, defined by a median value with a plus or minus range, etc. obtain.

Based on the calibration process described below, each first temperature set point value or range of first set point values is determined such that, for example, the syngas composition is unreacted hydrocarbon fuel and/or hydrogen and Free or substantially free of carbon-based CPOX reaction by-products corresponds to a desired synthesis gas composition. As an example, if the hydrocarbon fuel used is methane, the desired first temperature set point value is methane ( _CH4 ) and other by-products of the _CPOX reaction, such as _{C2H 10} H ₈ ), and other long-chain hydrocarbon molecules, especially those that can contribute to coke formation, sulfides, such as carbon disulfide (CS ₂ ), hydrogen sulfide (H ₂ S), sulfur dioxide ( does not contain anything that can compete for oxygen sites in the solid oxide anode electrode layer (150) and/or damage the solid oxide anode electrode layer (150) in the SOFC stack, such as SO ₂ ); Produces a substantially free syngas composition. In another example, if the hydrocarbon fuel used is propane (C ₃ H ₈ ), the desired first temperature set point value may contain propane, methane, and other byproducts of the CPOX reaction described above. Produces a substantially free syngas composition.

FIG. 15A is a graphical representation (1500) of the calibration data listed in the table (1505) of FIG. 15b. The data is the O:C or oxygen to carbon ratio _of the incoming hydrocarbon fuel air mixture (2025, 3025), T_CPOX, or the first temperature in degrees Celsius based on weight percent, % _CH4 and % _C2Hx . include. Referring to FIG. 15A, the O:C ratio is shown along the horizontal axis over a range of 1.2 to 1.5, and the O:C ratio is shown on the left vertical axis of FIG. 15A over a range of 608 to 630 degrees Celsius. T_CPOX(c) shown above or plotted against the first temperature. The data further includes the weight percent of undesirable hydrocarbon components such as methane (CH ₄ ) and (C ₂ H _x ) shown over the range 0.0 to 0.3 percent, or the right vertical axis of FIG. 15A. . Thus, _the right axis _contains various undesirable by-products of the CPOX _reaction , such as C ₂ H Sulfides such as carbon disulfide (CS ₂ ), hydrogen sulfide (H ₂ S), sulfur oxide (SO ₂ ), etc., which contain oxygen sites in the solid oxide anode electrode layer (150) in the SOFC stack. represents a measurement of what can compete with and/or damage the solid oxide anode electrode layer (150).

As best seen in Figure 15A, the plot (1510) of O:C ratio versus T_CPOX (°C) is linear. The plot (1510) shows that the temperature T_CPOX (°C), which corresponds to the instantaneous temperature sensed by the first thermal sensor (8030), increases linearly with increasing O:C ratio. In other words, as air is added to the hydrocarbon fuel air mixture (2025, 3025), the temperature T_CPOX (°C) increases.

Also, in FIG. 15A, the plot of O:C ratio versus % _CH4 (1515) is nonlinear. Plot (1515) shows that the proportion of methane remaining in the syngas composition decreases non-linearly with increasing O:C ratio. Therefore, when the proportion of unreacted methane is essentially zero, as the O:C ratio increases and T_CPOX increases, the proportion of unreacted methane decreases until the O:C ratio reaches 1.4 or more. do. As further shown in FIG. 15A, an O:C ratio of 1.4 corresponds to a T_CPOX temperature of 628°C. Also, in FIG. 15A, the plot of O:C ratio versus %C ₂ H _X (1520) is clearly not non-linear. Plot (1520) shows that the percentage of %C ₂ H _X remaining in the syngas composition is undetectable.

Accordingly, FIG. 15A shows that by detecting the temperature T_CPOX corresponding to the first temperature signal (8031), the O:C ratio and the syngas composition are determined based on the T_CPOX value alone, at least the T_CPOX temperature setpoint value or setpoint. The range of point values (1530) corresponds to _the exclusion of undesirable hydrocarbon components such as methane ( _CH4 ) ( _C2Hx ) and other long chain hydrocarbon molecules from the produced syngas. It clearly shows that it is characterized to such an extent that it can be selected as such. More specifically, the CPOX reaction supported while the T_CPOX temperature is maintained at a set point value within the range of set point values (1530) shown in FIG. 15A is free of undesirable hydrocarbon components. Additionally, T_CPOX temperature can be controlled simply by varying the oxidant flow rate. Therefore, based on the plot shown in FIG. 15A and the data listed in FIG. 15B, the first temperature set point range (1530) corresponds to an O:C ratio range of approximately 1.38 to 1.42. Corresponding to a set point temperature T_CPOX(C) of approximately 618-623°C. During steady-state operation, the electronic controller (190) samples the first temperature signal (8031) at a sampling frequency to produce a continuous stream of first temperature signal values (8031), each of which corresponds to the figure above. 9 to 14 corresponds to the instantaneous temperature of the heat transfer element supported in mating contact with the catalyst body. The electronic controller compares each first temperature signal value (8031) to a suitable set point temperature value or range of suitable set point values. The set point value is stored by an electronic controller, and different set point values or set point value ranges can be used for different hydrocarbon fuel types, different SOFC system configurations, different heat transfer element types, and operating modes, oxidizer types, fuel air mixtures. Other operating parameters such as temperature, DC power output of the SOFC system, etc. may be accommodated. The electronic controller does not operate when the sampled first temperature signal value (8031) is equal to or within the appropriate first temperature set point value. When the sampled first temperature signal value is not equal to or within the appropriate first temperature set point value, the electronic controller controls the mixing chamber (8015). to either increase or decrease the oxidant delivered to the oxidant flow modulator (8025) and then send one or more command and control signals to the oxidant flow modulator (8025) to The signal corresponds to either an increase or decrease in oxidant flow rate as required by its logical conclusion.

In one non-limiting exemplary mode of operation, when the sampled first temperature signal value (8031) is less than the minimum allowed first signal value, the electronic controller (190) controls the oxidant flow rate. Directs the modulator (8025) to increase the mass or volumetric flow rate of oxidant entering the mixing chamber (8015), thereby increasing the O:C ratio, resulting in an increase in the CPOX reaction temperature and a temperature T_CPOX (°C ) and the corresponding first temperature signal value (8031) increases correspondingly. Alternatively, when the sampled first temperature signal is greater than the maximum allowed first temperature signal value (8031), the electronic controller (190) instructs the oxidant flow modulator (8025) to Reducing the mass or volumetric flow rate of oxidant entering the chamber (8015) reduces the CPOX reaction temperature. In each case, an increase or decrease in the CPOX reaction temperature causes a change in the temperature of the heat transfer element thermally conductively coupled between the catalyst body (9005, 10005, 11005, 12005, 13005) and the first thermal sensor (8030). The temperature increases or decreases correspondingly. In a non-limiting exemplary embodiment, the sampling rate of the first signal ranges from approximately 5Hz to 100KHz. In a non-limiting exemplary embodiment, the minimum incremental change in oxidant volumetric flow rate is in the range of 0.1 to 2.0 standard cubic centimeters per minute (SCCM).

8.12.11.2 SOFC Reaction Temperature In an exemplary mode of operation, a second temperature signal (8041) is received by the electronic controller (190) from the second thermal sensor (8040). The second temperature signal (8041) may include analog or digital signals corresponding to voltage or current amplitudes, normalized voltage or current amplitudes, etc., such that each different voltage of the second temperature signal (8041) Or the current amplitude values correspond to different temperatures sensed by the second thermal sensor (8040). The electronic controller (190) stores one or more second temperature set point values. Each second temperature set point value corresponds to a second temperature signal value or range of values that corresponds to a SOFC reaction temperature that produces a desired result.

The desired result is any one of a DC power or current output value corresponding to a threshold, or a median, maximum, or other DC power or current amplitude output of DC power or current production by the SOFC fuel cell stack. may include. Other desired outcome criteria are, for example, if the exhaust gas composition is substantially free of unreacted anode gas components, _H2 and CO, and/or indicates incomplete conversion of the anode gas to electrical power. The composition of the exhaust gas exiting the system exhaust port (2165) or the exhaust gas exiting the SOFC tube into the combustion chamber (2135) when free of byproducts obtained. Still other desired outcome criteria are various measurable characteristics of fuel cell efficiency, such as electrical energy output per unit volume of hydrocarbon fuel input.

As discussed above with respect to the first set point temperature value, each fuel type and each mode of operation of the SOFC system has a different second temperature set point value that corresponds to only one hydrocarbon fuel type or only one mode of operation. The electronic controller (190) preferably stores a different second temperature set point value, etc. for each mode of operation for each of a plurality of different hydrocarbon fuel types. Accordingly, the electronic controller (190) may also sense the hydrocarbon fuel type being used by the SOFC system, or the user may input the hydrocarbon fuel type and other parameters of the SOFC system. . In any case, the electronic controller selects the appropriate second temperature set point value corresponding to the fuel type and mode of operation.

The second temperature set point value stored by the electronic controller (190) may include a second temperature signal value or a range of second temperature signal values corresponding to the second temperature set point. The correlation between the desired DC power and the second temperature set point value or second temperature signal value range is determined by system calibration described below. In addition to storing multiple secondary set point values or ranges corresponding to different hydrocarbon fuel types, the electronic controller can store other set point values or ranges, such as a safe maximum operating temperature, a minimum or threshold temperature for DC power, etc. Other temperature signal values corresponding to desired operating conditions may also be stored.

The electronic controller (190) periodically samples the second temperature signal (8041) received thereby and converts the sampled second temperature signal value to an appropriate second temperature set point or second temperature set point. Compare with the range of temperature set point values. If the sampled second temperature signal is equal to the second temperature set point or within the second set point range, the electronic controller is inoperative. If the sampled second temperature signal is not equal to the second temperature set point value or is not within the second set point value range, the electronic controller controls the amount of hydrocarbons delivered to the mixing chamber (8015). increases or decreases the flow rate of fuel and then sends one or more control and command signals to the hydrocarbon fuel flow modulator (8035), where the control signals are connected to the mixing chamber (8015). ) corresponds to either increasing or decreasing the flow rate of hydrocarbon fuel to ).

In one non-limiting exemplary mode of operation, when the second temperature signal value is less than the minimum allowed second temperature signal value, the electronic controller (190) causes the hydrocarbon flow modulator (8035) to , commands an increase in the mass or volumetric flow rate of hydrocarbon fuel entering the mixing chamber (8015). Alternatively, when the sampled second temperature signal is greater than the maximum allowed second temperature signal value, the electronic controller (190) instructs the hydrocarbon fuel flow modulator (8035) to 8015). In the first example, an increase in the flow rate of hydrocarbon fuel entering the mixing chamber (8015) increases the volume of hydrocarbon fuel that is converted to syngas and ultimately increases the temperature of the syngas and tubular SOFC rods. This increase in temperature ultimately increases the temperature of the outer enclosure wall sensed by the second thermal sensor (8040). In a second example, a reduction in the flow rate of hydrocarbon fuel entering the mixing chamber (8015) reduces the volume of hydrocarbon fuel that is converted to syngas and ultimately increases the temperature of the syngas and tubular SOFC rods. This decrease in temperature ultimately reduces the temperature of the outer enclosure wall sensed by the second thermal sensor (8040).

In this manner, the electronic controller (190) periodically samples the second signal (8041) generated by the second thermal sensor (8040) at a second signal sampling rate and controls the mixing chamber (8015) to Appropriate adjustments are made to increase or decrease the temperature sensed by the second thermal sensor (8040) by increasing or decreasing the mass or volumetric flow rate of the hydrocarbon fuel entering. The second signal sampling rate is in the range of approximately 5Hz to 100KHz. The minimum incremental change in hydrocarbon fuel volumetric flow rate ranges from 0.1 to 2.0 standard cubic centimeters per minute (SCCM).

As will be understood by those skilled in the art, changing the flow rate of oxidant to the mixing chamber (8015) without also changing the flow rate of the hydrocarbon fuel changes the O:C ratio. Similarly, when the flow rate of hydrocarbon fuel to the mixing chamber (8015) changes without changing the flow rate of oxidant, the O:C ratio also changes. As demonstrated by the plot in Figure 15A, changes in the O:C ratio, whether due to changing only the oxidant flow rate or only the hydrocarbon fuel flow rate, , resulting in a change in the temperature sensed by the first thermal sensor (8030). Similarly, changes in the O:C ratio, whether due solely to changing the oxidant flow rate or to changing the hydrocarbon fuel flow rate, result in changes in the composition of the syngas. This results in an increase in methane content as the O:C ratio becomes less than about 1.35.

According to one non-limiting exemplary method of operation of the present disclosure, the first control loop is operated by an electronic controller (190). In the first control loop, the first thermal sensor (8030) is sampled at a first sampling rate, e.g. Provide value. Additionally, an oxidant flow modulator (8025) is controlled to adjust the oxidant flow rate to increase or decrease the oxidant flow rate as needed to adjust the first temperature signal value to the set point value. or within a set point value corresponding to a first temperature signal stored by an electronic controller. The oxidant flow modulator (8025) may be adjusted at the same rate as the first sampling rate of 50Hz, but the first sampling rate of the first temperature signal value and the adjustment rate of the oxidant flow modulator (8025) are May be different. Preferably, the first control loop operates independently of the second control loop described below.

The exemplary non-limiting method of operation further includes operating a second control loop with an electronic controller (190). In a second control loop, the second thermal sensor (8040) is sampled at a second sampling rate, e.g. Provide value. In addition, a hydrocarbon fuel flow modulator (8035) is controlled to adjust the flow rate of the hydrocarbon fuel to increase or decrease the flow rate of the hydrocarbon fuel as needed to generate a second temperature signal value. The temperature is maintained at a set point value or within a range of a set point value corresponding to a second temperature signal stored by the electronic controller. The hydrocarbon fuel flow modulator (8035) may be adjusted at the same rate as the second sampling rate of 50 Hz, but the sampling rate of the second temperature signal value and the adjustment rate of the hydrocarbon fuel flow modulator (8035) are different. You can leave it there. Preferably, the second control loop operates independently of the first control loop described above.

The non-limiting exemplary operating method further includes operating a third control loop with an electronic controller (190). A third control loop converts each second temperature signal value corresponding to the second thermal sensor (8040) into a control failsafe corresponding to the position of the second thermal sensor stored by the electronic controller (190). Compare with temperature. The control fail-safe temperature corresponding to the second thermal sensor location is the highest safe operating temperature for the second thermal sensor (8040) location, and in this exemplary embodiment, the surface of the hot zone enclosure wall, or Any other surface of the first heat transfer path. When a control fail-safe temperature corresponding to the position of the second thermal sensor is detected by the electronic controller, the electronic controller closes the hydrocarbon fuel flow modulator (8035) to allow additional fuel to the mixing chamber (8015). configured to stop the flow of. While the hydrocarbon fuel flow modulator is closed, the electronic controller is configured to fully open the oxidant and cathode gas flow modulators (8025, 8050) to pump oxidant through the SOFC system for cooling. Ru.

The non-limiting exemplary operating method further includes operating a fourth control loop by an electronic controller (190). In the fourth control loop, the SOFC system operates at an intentionally high O:C ratio, for example, in response to the first elevated heat sensor value T_CPOX, as shown in plot (1510) of FIG. 15A. The temperature increase sensor value T_CPOX selected for the fourth control loop is greater than the range of setpoint value T_CPOX or sensor value T_CPOX (1530) used during normal operation. The fourth control loop may be used during startup mode, for example, to more rapidly heat the SOFC system to, for example, the SOFC reaction temperature sensed by the second thermal sensor (8040). A fourth control loop may also be used to intentionally overheat the SOFC system to clean, e.g., tar deposits, as a means to clean the catalyst layer (3090) and solid oxide anode electrode layer (150). You can also burn it down.

A fourth control loop is initiated to operate the SOFC system at an O:C ratio corresponding to the first elevated temperature sensor signal T_CPOX. In the example calibration chart of FIG. 15A, the first elevated temperature sensor signal T_CPOX corresponds to an O:C ratio of at least greater than about 1.4. In one non-limiting embodiment, the fourth control loop controls O for a predetermined period of time or until the first elevated thermal sensor signal T_CPOX reaches an upper setpoint corresponding to the maximum first thermal sensor signal T_CPOX. : Configured to run a SOFC system with a C ratio of 1.5 or higher.

The fourth control loop includes an increased value or range of values associated with the first elevated temperature sensor signal T_CPOX. The T_CPOX rise value provides a corresponding elevated O:C ratio that is greater than the O:C ratio corresponding to the setpoint temperature or setpoint temperature range (1530) used for normal operation. Preferably, the elevated O:C ratio is in the range of 2.0 to 2.2. Alternatively, the elevated temperature T_CPOX is a range of temperature values corresponding to the first temperature signal (8031) providing an O:C ratio between approximately 2.0 and 2.2.

One non-limiting exemplary embodiment of the fourth control loop sets the setpoint value or range of values (1530) corresponding to the first thermal sensor signal used for normal operation to the desired temperature increase O: changing to an increased T_CPOX setpoint value or range of values corresponding to the C ratio, and then a fourth control loop adjusts the oxidizer flow rate as needed without changing the hydrocarbon fuel flow rate. and increase the first temperature signal value to a temperature increase set point value or range of values of T_CPOX. After the desired period of time at the temperature increase or O:C ratio, the fourth control loop terminates its operation and returns the increased T_CPOX temperature setpoint value or range of values to be used for normal operation. A set point value or range of values (1530) corresponding to the first thermal sensor signal is returned and control is returned to the first and second control loops. Other parameters that can be used to terminate operation of the fourth control loop include monitoring the second temperature signal (8041) and as a means of determining when the SOFC stack has reached an acceptable operating temperature. Examples include monitoring the DC power or current amplitude produced by the SOFC stack.

Calibration Procedure According to the present disclosure, the weight percent of the anode gas components H ₂ and CO of the syngas is maximized, while unreacted hydrocarbons (e.g., CH ₄ , C ₂ H _X , and ethane (C ₂ H ₆ ) An optimization process is performed to minimize the weight percent of other long hydrocarbon chains, including propane (C ₃ H ₈ ), butane (C ₄ H ₁₀ ), etc. In some calibration procedures, the optimization The process also uses oxygen gas, water, nitrogen gas, carbon monoxide, carbon dioxide, tar (C ₁₀ H ₈ ), and carbon disulfide (CS ₂ ), hydrogen sulfide (H ₂ S), sulfur dioxide (SO ₂ ). More generally, the optimization process includes characterizing the weight percentages of other components of the syngas (2027), such as: The primary set point value or range of set point values corresponds to the value produced by the first thermal sensor (8030) and is a repeatable desired range associated with the characteristics of the CPOX response. As mentioned above, the desired result is the desired syngas composition, but a different, simpler desired result is a weight percent methane of less than 0.01%.

An optimization process is performed to qualify the system design based on a particular hydrocarbon fuel type. The system design includes the configuration and location of the heat transfer elements (9005, 10005, 11005, 12005, 13005), the configuration and location of the first thermal sensor (8031) relative to the heat transfer element, and the configuration and physics of the catalyst body (3030). dimensions, configuration and location of the second thermal sensor (8040), and repeatable desired results selected to characterize the CPOX reaction.

In a first calibration step, the SOFC system calibrates the current generated in, e.g., conduits (8017) and (8022), e.g. , the cathode gas flow rate in the conduit (8055), e.g., the syngas composition in the input manifold (3055), and the outlet of the SOFC stack, e.g., the exhaust gas composition in the combustion chamber (2135) of the SOFC system. installed within a calibration tool or instrument containing elements provided for measuring various operating parameters of the

The calibration tool or equipment includes at least one gas chromatograph probe positioned on the sample syngas exiting the catalyst body (3030) and a gas chromatograph configured to perform a desired syngas composition analysis. Optionally, a second gas chromatograph probe is positioned to sample the exhaust gas exiting the SOFC stack, e.g., disposed inside the combustion chamber (2135), and the second gas chromatograph probe samples the exhaust gas exiting the SOFC stack. configured to perform compositional analysis. A calibration tool or fixture provides a volumetric flow rate associated with each of the oxidant flow modulator (8025) and the hydrocarbon fuel modulator (8035) and, optionally, the cathode flow modulator (8050) for measuring appropriate gas flow rates. The mass of the meter is also provided. Calibration tools or supplies may, for example, measure sample thermal sensor signals (8031) and (8040), oxidant, hydrocarbon fuel, and cathode air flow rates to sample DC power values (e.g., current and/or power amplitude). Set point values or value ranges for each of thermal sensor signals (8031) and (8040) to regulate, sample flow meters, store set point values, and analyze and store gas composition data. A calibration controller configured to operate the SOFC system, such as to determine and select. A calibration controller is associated with collecting gas chromatograph sample data, flow meter data, and first and second thermal sensor data to achieve one or more repeatable desired results regarding characteristics of the CPOX reaction. and/or configured to perform logical operations associated with performing a calibration process by analyzing data associated with achieving repeatable desired results related to characteristics of the SOFC reaction. be done.

In a second calibration step, the SOFC system is brought into a steady state operating mode where the SOFC reaction is initiated and the SOFC system is producing DC power. The operating parameters of the SOFC system are then varied by the calibration controller as necessary to achieve repeatable desired results related to the characteristics of the SOFC reaction. As mentioned above, the desired results related to the characteristics of the SOFC reaction may be related to the characteristics of the DC power or current output. In one example, the second signal value output by the second thermal sensor (8040) is monitored over a range of hydrocarbon fuel flow rates while the oxidizer flow rate is constant, and over a range of O:C ratios. Plot the output DC power. In one non-limiting exemplary embodiment, the calibration system has a set point corresponding to the onset of DC power output, a set point corresponding to the maximum obtainable DC power output, and a set point corresponding to the center DC power output. A second temperature signal set point value or a range of second temperature signal set point values may be selected that corresponds to a DC power output characteristic such as .

In another non-limiting exemplary embodiment, the calibration system determines a second temperature signal set point value or a composition of the exhaust gas exiting the SOFC stack that demonstrates that the exhaust gas is substantially free of anode gas components. A range of second temperature signal set point values may be selected that corresponds to the object. In yet another non-limiting exemplary embodiment, the calibration system comprises a second temperature signal set point value, or a range of second temperature signal set point values, or a ratio of the flow rate of the hydrocarbon fuel to the direct current output. etc. can be selected. Regardless of which desired output of the SOFC system is being evaluated to determine the second signal value output by the second thermal sensor (8040), the second signal value output by the second thermal sensor (8040) A second signal value is monitored over a range of hydrocarbon fuel flow rates while the oxidant flow rate is constant to plot the desired output power of the SOFC system versus the O:C ratio. In addition, these plots show that one or more different oxidants are May be repeated for flow rate.

In the third calibration step, the weight percent of each or selected syngas components is determined by analyzing a sample of syngas by gas chromatography over a plurality of different O:C ratios. The O:C ratio is varied by modifying only the oxidant flow rate, a process performed by the calibration controller. During the third calibration step, the hydrocarbon fuel flow rate is not changed. The calibration controller also samples the first temperature signal (8031) and oxidant flow meter data over a plurality of different O:C ratios and stores the first signal value and the oxidant flow value. The calibration controller is configured to analyze the syngas component weight percent for each O:C ratio and to associate a first temperature signal value and an oxidant flow value with each O:C ratio. Additionally, during the third calibration step, the calibration controller is configured to monitor and record data associated with the desired output of the SOFC system. Data related to the desired output of the SOFC system includes at least a second temperature signal (8041) at each O:C ratio, hydrocarbon fuel and cathode air flow rates, DC output power characteristics of the SOFC stack, gas chromatography data. and the composition of the exhaust gas exiting the SOFC stack as determined from the SOFC stack.

In a fourth calibration step, the weight percent of each syngas component corresponding to each of the plurality of different O:C ratios produced by the third calibration step is analyzed to determine which O:C ratios correspond to the desired syngas. Determine if the composition always produces, for example, if the weight percent of methane is less than 0.01%. A fourth calibration step includes determining, by the calibration controller, a first temperature signal value or a first temperature signal value modified by the first thermal sensor (8030) associated with providing the desired syngas composition. further comprising determining a range of. As shown by the plot (1510) of FIG. 15A, the first set point value or range of values (1530) corresponds to the lowest temperature of the first temperature signal value T_CPOX that satisfies the desired syngas composition. However, other higher temperature values may be selected without departing from this disclosure. Once the first set point value or range of set point values (1530) is selected, a fixed hydrocarbon fuel corresponding to the second set point value or range of values corresponding to the second thermal sensor (8040) is selected. Using other fixed hydrocarbon fuel flow rates to refine the SOFC system operation by making small changes to each of the first and second set point values. 4 calibration process can be re-run.

When using a calibration fixture, the calibration procedure is performed only once for a given SOFC system configuration using a given hydrocarbon fuel type, and the CPOX associated with the first thermal sensor (8030) The reaction temperature set point and the SOFC stack temperature set point associated with the second thermal sensor (8040) need to be determined.

The calibration fixture optionally also includes a plurality of different hydrocarbon fuel sources, each corresponding to a different hydrocarbon fuel type, to calibrate the SOFC system for each of the plurality of different hydrocarbon fuel types. Accordingly, the fifth calibration step includes repeating the calibration step two to four times for each of a plurality of different hydrocarbon fuel types, thereby providing a different CPOX reaction temperature set point and a different The SOFC stack temperature set point can now be selected.

Although the invention has been described above in terms of preferred embodiments, those skilled in the art will also appreciate that it is not limited thereto. The various features and aspects of the invention described above can be used individually or together. Additionally, while the invention has been described in a particular environment and in the context of a particular application (e.g., a solid oxide fuel system including a fuel reformer module that performs an exothermic reaction), those skilled in the art will appreciate that It is recognized that its usefulness is not limited thereto, and that the present invention may be beneficially utilized in any number of environments and implementations in which it is desirable to manage thermal energy in high temperature corrosive environments, where combustible materials are processed. You will recognize it. Therefore, the following claims should be construed in light of the full scope and spirit of the invention disclosed herein.

Claims (15)

A fuel reformer module for initiating catalytic partial oxidation (CPOX) to reform a hydrocarbon fuel oxidizer mixture and delivering a syngas reformate therefrom, the fuel reformer module comprising:
a catalyst body having an input end and an output end, the catalyst body extending between the input end and one of the output end of the catalyst body and a fuel passage output end not at the output end of the catalyst body; a catalytic body comprising a solid non-porous ceramic substrate formed to include a plurality of catalytic fuel passages;
a catalyst layer formed on an inner surface of each of the plurality of catalytic fuel passages, the layer comprising a material selected to initiate the CPOX reaction;
a thermally conductive element comprising a material having a thermal conductivity coefficient of 50 W/m°K or more and thermally conductively coupled to the catalyst body over a contact surface area;
a first thermal sensor, the first thermal sensor being thermally conductively coupled to the thermally conductive element for generating a first temperature signal corresponding to a temperature sensed by the first thermal sensor; A fuel reformer module comprising: The input end and the output end are separated by a first longitudinal dimension extending along the longitudinal axis of the catalyst body, and the contact surface area is separated by a second longitudinal dimension extending along the longitudinal axis of the catalyst body. The fuel reformer of claim 1, having a longitudinal dimension, the second longitudinal dimension being at least one quarter of the first longitudinal dimension. 3. The fuel reformer of claim 2, wherein the second longitudinal dimension is within a range of one quarter to one half of the first longitudinal dimension. 3. The fuel reformer of claim 2, wherein the second longitudinal dimension is within a range from one quarter to equal to the first longitudinal dimension. The catalyst body has a first longitudinal dimension extending between the input end and the output end along a first longitudinal axis of the catalyst body, and an outer diameter about the longitudinal axis. The fuel reformer according to claim 1, wherein the fuel reformer has a cylindrical shape having dimensions, the first longitudinal dimension is 25 mm or more, and the outer dimension is 25 mm or more. The contact surface area promotes a sufficiently high thermal conductivity between the catalytic body and the heat transfer element such that the first thermal sensor detects a change in the contact surface area with an average temperature of 1 to 2 degrees Celsius. is sized to sense in less than 30 seconds, the material volume of the heat transfer element is sized to promote a sufficiently high thermal conductivity between the catalyst body and the heat transfer element, and the material volume of the first The fuel reformer of claim 1, wherein the thermal sensor is sized to sense a change in the contact surface area at an average temperature of 1 to 2 degrees Celsius in less than 30 seconds. Each of the contact surface area and the material volume of the heat transfer element promotes a sufficiently high thermal conductivity between the catalyst body and the heat transfer element such that the first thermal sensor a first electrode sized to sense a change in average temperature of 1 to 2 degrees Celsius in less than 30 seconds, the input end and the output end extending along the longitudinal axis of the catalyst body; separated by a longitudinal dimension of said plurality of catalytic fuel passages, each of said plurality of catalytic fuel passages extending between said input end and said output end along a longitudinal axis of a different fuel passage parallel to said first longitudinal axis. 2. The fuel reformer of claim 1, wherein the fuel reformer extends between. The non-porous ceramic substrate includes a solid non-porous ceramic foam material, and the plurality of catalytic fuel passageways are located at the input end, the output end of the catalyst body, and the fuel not at the output end of the catalyst body. 6. The fuel reformer of claim 5, comprising a plurality of interconnected open cells extending between one of the passageway output ends. the heat transfer element comprises a prism rod disposed in mating contact with the outer diameter of the catalyst body, the longitudinal axis of the prism rod oriented substantially parallel to the first longitudinal axis; and the heat transfer element comprises a prism rod disposed in mating contact with the outer diameter of the catalyst body, the longitudinal axis of the prism rod being substantially the first longitudinal axis. 6. The fuel reformer of claim 5, wherein the fuel reformer is parallel oriented. The heat transfer element includes a cylindrical segment disposed in mating contact with the outer diameter of the catalyst body, the longitudinal axis of the cylindrical segment being substantially parallel to the first longitudinal axis. 6. The fuel reformer of claim 5, wherein the cylindrical segments are parallel oriented and include contact surface areas formed with a radius of curvature that matches the radius of curvature of the outer peripheral surface of the cylindrical catalyst body. The heat transfer element comprises a hollow cylinder having an inner diameter disposed in mating contact with the outer diameter of the catalyst body, the longitudinal axis of the hollow cylinder being in contact with the first longitudinal axis. oriented substantially parallel to said hollow cylinder, said hollow cylinder being formed with an inner diameter sized to substantially match said outer diameter of said catalyst body, said hollow cylinder being formed by said hollow cylinder; 6. The fuel reformer of claim 5 formed with an outer diameter sized to provide a desired thickness of the annular wall. The heat transfer element comprises a helical portion of a hollow cylinder having an inner diameter disposed in mating contact with the outer diameter of the catalytic body, the longitudinal axis of the helical portion of the hollow cylinder comprising: oriented substantially parallel to the first longitudinal axis, the helical portion of the hollow cylinder having an inner diameter sized to substantially match the outer diameter of the catalyst body; 4. The helical portion of the hollow cylinder is formed with an outer diameter sized to provide a desired thickness of the helical annular wall formed by the helical portion of the hollow cylinder. 5. The fuel reformer according to 5. the catalyst body is formed to include a central cylindrical cavity extending completely or partially through the cylindrical catalyst body, the central cylindrical cavity being formed with an inner diameter and configured to the element comprises a solid cylindrical element disposed inside the central cylindrical cavity, the internal diameter of the central cylindrical cavity being sized to substantially match the external diameter of the solid cylindrical element; , the contact surface area formed between the solid cylindrical element and the central cylindrical cavity and the material volume of the solid cylindrical element are respectively sufficient to provide sufficient space between the catalyst body and the heat transfer element. 5. The first thermal sensor is sized to sense an average temperature change of 1 to 2 degrees Celsius of the contact surface area in less than 30 seconds. The fuel reformer described in . A SOFC system comprising the fuel reformer module according to claim 1,
producing the hydrocarbon fuel oxidizer mixture by mixing a hydrocarbon fuel received from a hydrocarbon fuel source with an oxidizer received from an oxidizer source for delivery to the input end of the catalyst body; a fuel oxidizer control module configured to: a hydrocarbon fuel flow modulator disposed between the hydrocarbon fuel source and the input end; an oxidizer flow modulator disposed in the fuel oxidizer control module;
an electronic controller operative to send independent command and control signals to each of the hydrocarbon fuel flow modulator and the oxidizer flow modulator;
A solid oxide fuel cell (SOFC) stack comprising a plurality of individual SOFC fuel cells each comprising a solid oxide anode electrode layer, the syngas reformate output from the fuel reformer module comprising: a solid oxide fuel cell (SOFC) stack with flow over the solid oxide anode electrode layer to initiate and maintain the SOFC reaction;
A hot zone enclosure comprising a plurality of hot zone enclosure walls joined together to enclose a hot zone cavity surrounding the SOFC stack, the hot zone enclosure being formed from a material having a thermal conductivity coefficient of greater than or equal to 100 W/m°K. , a hot zone enclosure joined together to form a first continuous heat transfer path;
a second thermal sensor thermally conductively coupled to a surface of the first heat transfer path for generating a second temperature signal corresponding to a temperature of the surface of the first heat transfer path;
a first setpoint temperature value range stored by the electronic controller, the first temperature signal value range known to produce the syngas reformate having a desired syngas composition; a first set point value range corresponding to a calibrated operating temperature range corresponding to;
a second setpoint temperature value range stored by the electronic controller, the calibrated operating temperature range of a second temperature signal value being known to produce desired performance characteristics of the SOFC stack; further comprising a second set point value range corresponding to
The electronic controller operates a first control loop based on sampling the first thermal sensor signal value, the first control loop converting the sampled first temperature signal value to the first temperature signal value. instructing the oxidant flow modulator to increase or decrease the oxidant flow rate to maintain the oxidant flow rate within a set point value of
The electronic controller operates a second control loop based on the sampled second thermal sensor signal value, and the second control loop operates the second sampled temperature signal value on the second sampled temperature signal value. The SOFC system instructs the hydrocarbon fuel flow modulator to increase or decrease the flow rate of the hydrocarbon fuel to maintain it within a set point value of . delivering the hydrocarbon fuel oxidizer mixture to the fuel reformer of claim 1 by a fuel oxidizer control module, wherein the fuel oxidizer control modulator is configured to communicate the hydrocarbon fuel oxidizer mixture with the hydrocarbon fuel source; a hydrocarbon fuel flow modulator disposed between the input end of the media and an oxidant flow modulator disposed between the oxidant source and the input end of the catalyst body;
delivering a first command and control signal from an electronic controller to the oxidant flow modulator to adjust the flow rate of oxidant;
delivering a second command and control signal from an electronic controller to the hydrocarbon fuel flow modulator to adjust the flow rate of the hydrocarbon fuel;
delivering the syngas reformate output from the catalytic body to a solid oxide fuel cell (SOFC) stack, each SOFC stack delivering the syngas reformate output from the catalytic body; comprising a plurality of individual SOFC fuel cells including a solid oxide anode electrode layer in fluid communication, the synthesis gas reacting with the solid oxide anode electrode layer to initiate a SOFC reaction at a SOFC reaction temperature;
sampling, by the electronic controller, a first temperature control signal value generated by the first temperature sensor;
sampling, by the electronic controller, a second temperature control signal value generated by a second temperature sensor, the second thermal sensor increasing the temperature in proportion to a temperature change in the SOFC reaction temperature; being arranged to detect a temperature of a surface that causes a change in temperature;
storing, by the electronic controller, a range of first set point temperature values, the first range of set point values producing the syngas reformate having a desired syngas composition; corresponding to a calibrated operating temperature range corresponding to a range of first temperature signal values known to be
storing, by the electronic controller, a range of second set point temperature values, the range of second set point values known to produce desired performance characteristics of the SOFC stack; a calibrated operating temperature range corresponding to a range of second temperature signal values;
operating a first control loop by the electronic controller based on the sampling of the first temperature sensor signal value, the first control loop increasing or decreasing the oxidant to increase or decrease the oxidant; commanding the oxidant flow modulator to maintain a sampled first temperature signal value within the first set point value;
operating a second control loop by the electronic controller based on the sampling of the second thermal sensor signal value, the second control loop increasing or decreasing the flow rate of the hydrocarbon fuel; commanding the hydrocarbon fuel flow modulator to maintain the sampled second temperature signal value within the second set point value; storing, by the electronic controller, a range of first set point temperature values corresponding to a desired composition of the syngas reformate output from the first set point temperature value corresponding to a plurality of different hydrocarbon fuel types; further comprising storing a plurality of first set point temperature values having respective ranges of set point values, _wherein the plurality of different hydrocarbon fuel types include methane, ( _CH4 ), ethane ( _C2H6 ). , propane (C ₃ H ₈ ), and butane (C ₄ H ₁₀ ).