JP2019009082A - Fuel cell system - Google Patents

Abstract

To provide an inexpensive fuel cell system, by simplifying the structure without lowering power generation efficiency.SOLUTION: A fuel cell system includes a raw material/water mixture regulator 18. The raw material/water mixture regulator 18 comprises a raw material jet pipe 18a having a nozzle 18c and jetting a pressed raw material for reforming to a reforming section 32, a reforming water outflow pipe 18b drawing out the reforming water for the opening 18c1 of the nozzle 18c at a position adjacent to the raw material pump 11a1, a needle valve 18e provided in the reforming water outflow pipe 18b, and changing the cross-sectional area of a flow path where the reforming water passes through a through hole 18d1, and a needle valve adjustment mechanism 18h for moving the needle valve 18e in the direction of the axis line. The raw material/water mixture regulator 18 supplies the raw material for reforming having a flow velocity increased by the nozzle 18c of the raw material jet pipe 18a, and the reforming water supplied from the reforming water outflow pipe 18b, while blending, to the reforming section 32.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fuel cell system.

  Conventionally, for example, a fuel cell system disclosed in Patent Document 1 below is known. In this conventional fuel cell system, the reforming water is supplied to the evaporation section by sucking the reforming water into the pump chamber by reciprocating the plunger and pressurizing the reforming water and discharging it from the pump chamber. It has a pump.

  Conventionally, for example, a humidifier disclosed in Patent Document 2 below is also known. This conventional humidifier has a heating element that includes a porous structure of electrically resistive and thermally conductive material and is configured to evaporate liquid that passes through the porous structure.

  Furthermore, conventionally, for example, a sprayer disclosed in Patent Document 3 below is also known. This conventional sprayer sprays a coating composition such as a cosmetic with compressed gas, a sprayer body having a nozzle that is a spray outlet of the coating composition, and a gas supply unit that supplies compressed gas to the sprayer body. And a composition supply tank for supplying the coating composition.

Japanese Patent Laid-Open No. 2006-72055 Special table 2014-506486 gazette Japanese Patent Laying-Open No. 2015-177922

  In general, in a fuel cell system, a reforming section to which a mixed gas in which a reforming raw material and steam are mixed is supplied, and the mixed gas is reformed by a steam reforming reaction generated inside the reforming section. Reformed gas (fuel) is generated. Then, the generated reformed gas (fuel) is supplied to the fuel cell to generate power.

  By the way, in the conventional fuel cell system, an evaporating section is provided to evaporate the reforming water to generate a mixed gas, and a raw material pump and reforming water for supplying a reforming raw material to the evaporating section. A reforming water pump is required to supply the water. Therefore, the conventional fuel cell system requires a space for providing the raw material pump and the reforming water pump, and also requires a space for providing an evaporation unit for generating the mixed gas. There is a concern that the size and manufacturing cost of the product will increase.

  In this regard, for example, it is conceivable to provide the conventional humidifier instead of the evaporation unit to generate water vapor from the reformed water. However, when the conventional humidifier is used, it is necessary to always supply power to the porous structure during the operation of the fuel cell system. Problem arises.

  In general, in the reforming section, in order to promote the steam reforming reaction, fuel off-gas and oxidant off-gas generated in power generation by the fuel cell are burned and heated. For this reason, when steam is generated from reformed water, for example, the reformed water atomized using the conventional sprayer is supplied to the reforming unit as a mixed gas together with the reforming raw material, It is conceivable to generate water vapor at By the way, when reforming a mixed gas to reformed gas (fuel) by a steam reforming reaction, the supply amount (flow rate) of reforming raw material and the supply amount (flow rate) of reforming water are precisely controlled. It is necessary to In this regard, the conventional sprayer simply sprays a coating composition made of powder, high-viscosity, or the like, and does not control the supply amount (flow rate) of the coating composition.

  The present invention has been made to solve the above problems. That is, an object of the present invention is to provide an inexpensive fuel cell system with a simplified structure without reducing power generation efficiency.

  In order to solve the above problems, a fuel cell system according to claim 1 is directed to a fuel cell that generates power from a fuel cell that generates power using fuel and an oxidant gas, a reforming raw material, and reformed water. A reforming section for supplying fuel to the fuel, a combustion section for deriving combustion exhaust gas by burning fuel off-gas and oxidant gas from the fuel cell, and a reforming material supply connected to a reforming material supply source A reforming material supply device that pumps the reforming material from the supply source to the reforming unit, a condenser that condenses water vapor contained in the combustion exhaust gas and generates condensed water, and reforming A reforming water tank that is disposed above the unit and below the condenser and stores the condensed water supplied from the condenser as reforming water, and the reforming water in the reforming water tank connected to the reforming water tank. Water reforming water supply pipe that supplies water to the reforming section by dropping water by its own weight and power generation of the fuel cell And a control device that performs overall control, the fuel cell system having a nozzle connected to the reforming material supply pipe and directed to the reforming unit, A raw material injection pipe for injecting into the reforming section and a reforming raw material supply apparatus side or a reforming section side with respect to the first opening which is connected to the reforming water supply pipe and is the nozzle opening of the raw material injection pipe A reforming water outflow pipe for flowing out the reforming water at a position adjacent to the inside of the reforming water outflow pipe, and the tip of the reforming water outflow pipe can be moved along the axis of the reforming water outflow pipe. The flow passage cross-sectional area of the flow passage formed by the outer peripheral surface of the tip portion and the inner peripheral surface of the second opening and passing through the reforming water is advanced and retracted with respect to the second opening which is the opening of the water outlet pipe. A shaft member to be changed, and a drive member connected to the proximal end portion of the shaft member to move the shaft member along the direction of the axis. The mixing unit is configured to mix the reforming raw material whose flow velocity is increased by the nozzle of the raw material injection pipe and the reforming water supplied from the reforming water outflow pipe into the reforming unit. Configured to supply.

  According to this, in the fuel cell system of the present invention, the reforming raw material pumped by the reforming raw material supply device passes through the nozzle of the raw material injection pipe and the flow velocity increases, so that the first opening of the nozzle The pressure in the vicinity, that is, the portion where the second opening is located, drops, and the reforming water is sucked out from the second opening of the reforming water outflow pipe. Thereby, in the fuel cell system of this invention, it is not necessary to pressurize and supply reforming water, and the reforming water pump provided in the conventional fuel cell system can be omitted. Therefore, the fuel cell system of the present invention can reduce the manufacturing cost compared to the conventional fuel cell system.

  In the mixing portion, the shaft-like member that is advanced and retracted by the drive member is formed by the cross-sectional area of the flow path, that is, the outer peripheral surface at the tip of the shaft-like member and the inner peripheral surface of the second opening of the reforming water outflow pipe. Since the channel cross-sectional area of the channel can be changed, the supply amount (flow rate) of the reforming water supplied to the reforming unit can be adjusted. Therefore, the mixing unit can supply a mixed gas in which the reforming raw material and the reforming water are adjusted to the reforming unit.

  Further, in the fuel cell system of the present invention, the driving member is operated only when the shaft member is moved in the axial direction in the mixing section to change the supply amount of the reforming water, so that the power consumption is extremely reduced. be able to. Thereby, the fuel cell system of this invention can prevent that power generation efficiency falls.

It is the schematic which shows the outline | summary of embodiment of the fuel cell system by this invention. It is sectional drawing which shows the structure of the fuel and water mixing regulator of FIG. FIG. 3 is a cross-sectional view illustrating stopping of reformed water in the fuel / water mixing regulator of FIG. 2. It is a graph for demonstrating a target supply amount. It is sectional drawing explaining the fuel and water mixing regulator which concerns on a 1st modification. It is sectional drawing explaining the fuel and water mixing regulator which concerns on a 2nd modification.

  Hereinafter, a fuel cell system 1 according to an embodiment of the present invention will be described with reference to the drawings. In the following embodiments and each modification, the same or equivalent parts are denoted by the same reference numerals in the drawings. Each figure used for explanation is a conceptual diagram, and the shape of each part may not necessarily be exact.

  The fuel cell system 1 includes a power generation unit 10 and a hot water tank 21 as shown in FIG. The power generation unit 10 includes a casing 10a, a fuel cell module 11 (30), a heat exchanger 12, an inverter device 13, a water purifier 14, a reforming water tank 15, a control device 16, and a raw material / water mixing adjustment as a mixing unit. A container 18 is provided. The fuel cell module 11 (30), the heat exchanger 12, the inverter device 13, the water purifier 14, the reforming water tank 15, the control device 16, the raw material / water mixing regulator 18 and the hot water tank 21 are provided in the housing 10a. Contained. The hot water storage tank 21 may be provided separately from the power generation unit 10, that is, outside the housing 10a.

  As will be described later, the fuel cell module 11 includes at least a fuel cell 33. The fuel cell module 11 is supplied with reforming raw material, reforming water, and cathode air. Specifically, the fuel cell module 11 has one end connected to the supply source Gs and the other end of the reforming material supply pipe 11a to which the reforming material is supplied. Connected through. The reforming raw material supply pipe 11 a is provided with a raw material pump 11 a 1 (reforming raw material supply device) that supplies the reforming raw material to the reforming unit 32. The fuel cell module 11 has one end connected to the reforming water tank 15 and the other end of the reforming water supply pipe 11b to which the reforming water is supplied via the raw material / water mixing adjuster 18. . The reforming water supply pipe 11b connects the reforming water tank 15 and the reforming unit 32 via the raw material / water mixing adjuster 18, and drops the reforming water in the reforming water tank 15 by its own weight. The raw material / water mixing regulator 18 is supplied.

  Further, the fuel cell module 11 has one end connected to the cathode air blower 11c1 and the other end of the cathode air supply pipe 11c to which the cathode air is supplied. The cathode air blower 11 c 1 is an oxidant gas supply device that supplies an oxidant gas (for example, air, oxygen) to the fuel cell 33.

  The heat exchanger 12 is supplied with combustion exhaust gas exhausted from the fuel cell module 11 and supplied with hot water from the hot water storage tank 21, and includes combustion exhaust gas (including exhaust heat from the fuel cell 33 and the reforming unit 32). Heat exchanger) and hot water storage. The heat exchanger 12 is a condenser that performs heat exchange between the combustion exhaust gas and the hot water storage, and condenses water vapor contained in the combustion exhaust gas to generate condensed water. The stored hot water is a heat medium (exhaust heat recovery water) that recovers exhaust heat of combustion exhaust gas.

  The heat exchanger 12 includes a casing 12b. An exhaust pipe 11d from the fuel cell module 11 is connected to the upper part of the casing 12b. A drain pipe 11e connected to the outside air (atmosphere) is connected to the lower part of the casing 12b. A condensed water supply pipe 12a connected to the water purifier 14 and then to the reformed water tank 15 is connected to the bottom of the casing 12b. A combustion exhaust gas passage through which the combustion exhaust gas passes is formed in the casing 12b. A heat exchanging portion (condensing portion) 12c connected to the hot water circulation line 22 is disposed in the combustion exhaust gas passage. Hot water is flowing in the heat exchanging portion 12c, and combustion exhaust gas is flowing outside the heat exchanging portion 12c. It is preferable that the hot water and the combustion exhaust gas flow in opposite directions.

  In the heat exchanger 12 configured as described above, the combustion exhaust gas from the fuel cell module 11 is introduced into the casing 12b through the exhaust pipe 11d, and passes through the heat exchange section 12c through which the hot water is circulated. Heat is exchanged with water to be condensed and cooled. Thereafter, the combustion exhaust gas is discharged to the outside through the exhaust pipe 11d. Condensed condensed water falls by its own weight and is supplied to the water purifier 14 and then to the reformed water tank 15 through the condensed water supply pipe 12a. On the other hand, the hot water stored in the heat exchange unit 12c is heated and discharged.

  The heat exchanger 12, the hot water tank 21, and the hot water circulation line 22 described above constitute an exhaust heat recovery system 20. The exhaust heat recovery system 20 recovers and stores the exhaust heat of the fuel cell module 11 in hot water storage.

  The hot water tank 21 is a sealed and pressure resistant container. The temperature distribution in the hot water storage tank 21 is basically divided into two layers having different temperatures. The upper layer is a layer having a relatively high temperature (for example, 50 degrees or more), and the lower layer is a layer having a relatively low temperature (for example, 20 degrees or less (temperature of tap water)). The upper and lower layers are at substantially the same temperature. The hot water storage tank 21 stores hot water, and is connected to a hot water circulation line 22 through which the hot water circulates (circulates in the direction of the arrow in the figure).

  A hot water circulating pump 22a, a heat exchanger hot water inlet temperature sensor 22b, a heat exchanger 12, and a heat exchanger hot water outlet temperature sensor 22c are arranged on the hot water circulating line 22 in order from the lower end to the upper end. Has been.

  The heat exchanger hot water inlet temperature sensor 22 b is provided in the hot water circulation line 22 between the hot water outlet of the hot water tank 21 and the hot water inlet of the heat exchanger 12. The heat exchanger hot water storage water inlet temperature sensor 22b is preferably provided in the vicinity of the hot water storage water inlet of the heat exchanger 12. The heat exchanger hot water inlet temperature sensor 22 b detects the temperature of hot water introduced into the heat exchanger 12 (hereinafter also referred to as hot water temperature) and transmits it to the control device 16.

  The heat exchanger hot water outlet temperature sensor 22 c is provided in the hot water circulation line 22 between the hot water outlet of the heat exchanger 12 and the hot water inlet of the hot water tank 21. The heat exchanger hot water outlet temperature sensor 22c is preferably provided in the vicinity of the hot water outlet of the heat exchanger 12. The heat exchanger hot water outlet temperature sensor 22 c detects the temperature of the hot water derived from the heat exchanger 12 and transmits it to the control device 16.

  The inverter device 13 receives DC power (voltage) output from the fuel cell 33, converts the DC power (voltage) into predetermined AC power (voltage), and connects it to an AC system power supply 17a and an external power load 17c (for example, an electrical appliance). Output to the power line 17b. The inverter device 13 is a power conversion device that converts DC power supplied from the fuel cell 33 into AC power. The external power load 17c is a load device to which power from the system power source 17a and power from the inverter device 13 are supplied. The inverter device 13 receives AC power (voltage) from the system power supply 17a via the power supply line 17b and converts it to predetermined DC power (voltage) to convert auxiliary equipment (each pump, blower, etc.) and control device. 16 is output.

  The water purifier 14 purifies condensed water with ion exchange resin. The water purifier 14 communicates with the reformed water tank 15 so that purified water that has been purified is supplied to the reformed water tank 15.

  The reforming water tank 15 stores the condensed water supplied from the heat exchanger 12 and thus the water purifier 14 as reforming water, and supplies the reforming water to the reforming unit 32. The reforming water tank 15 is disposed above the reforming unit 32 and below the heat exchanger 12 (condenser). In other words, the reforming water tank 15 is disposed below the heat exchanger 12 and above the reforming unit 32. In the reformed water tank 15, a water amount sensor 15a for detecting the amount of water in the reformed water tank 15 (water level: hereinafter also referred to as “tank water amount”) is disposed. The detection result of the water amount sensor 15 a is output to the control device 16. The water amount sensor 15a is, for example, a float sensor, and is a sensor that converts the vertical amount of the float into a resistance value using a variable resistor (potentiometer) and displays the water amount (residual water amount) by the vertical movement of the resistance value. .

  The control device 16 controls the operation of the fuel cell system 1 by driving the auxiliary machine. The control device 16 has a microcomputer (not shown). The microcomputer includes an input / output interface, a CPU, a RAM, and a ROM (all not shown) connected to each other via a bus. The CPU performs the overall operation of the fuel cell system 1. The RAM temporarily stores variables necessary for execution of the control program, and the ROM stores the control program.

  Next, the raw material / water mixing adjuster 18 as a mixing unit will be described. As shown in FIGS. 1 and 2, the raw material / water mixing regulator 18 is connected to the reforming raw material supply pipe 11a and to the reforming water supply pipe 11b. The raw material / water mixing adjuster 18 includes the reforming raw material pumped from the supply source Gs by the raw material pump 11a1 through the reforming raw material supply pipe 11a and the bottom (or lower side surface) of the reforming water tank 15. The reforming water supply pipe 11a connected to the reforming water dropped from the reforming water tank 15 by its own weight is adjusted to a predetermined ratio and mixed. Here, the reforming raw materials include natural gas (mainly composed of methane gas), gas fuel for reforming such as LP gas, and liquid fuel for reforming such as kerosene, gasoline, and methanol. Is explained in natural gas. The supply source Gs is, for example, a city gas supply pipe or an LP gas cylinder.

  As shown in FIG. 2, the raw material / water mixing adjuster 18 includes a raw material injection pipe 18a connected to the reforming raw material supply pipe 11a and a reforming water outflow pipe 18b connected to the reforming water supply pipe 11b. ing. In the present embodiment, as shown in FIG. 2, the reforming water outflow pipe 18b has an outer diameter smaller than the inner diameter of the raw material injection pipe 18a, and is disposed coaxially inside the raw material injection pipe 18a. Is done. That is, in the raw material / water mixing adjuster 18 of the present embodiment, the raw material injection pipe 18a and the reformed water outflow pipe 18b form a double pipe structure. The inner diameter and outer diameter of the raw material injection pipe 18a are set to be larger than the inner diameter and outer diameter of the reforming raw material supply pipe 11a.

  The raw material injection pipe 18 a has a nozzle 18 c having an opening 18 c 1 as a first opening that opens toward the reforming section 32. The nozzle 18c is mixed with a reforming raw material and mist-like reforming water (hereinafter, the mixed reforming raw material and mist-like reforming water are referred to as “mixed gas”), as will be described later. Is connected to a mixed gas supply pipe 11 f that supplies the reforming section 32.

  As shown in FIG. 2, the reforming water outflow pipe 18b is connected to the reforming water supply pipe 11b at a substantially central portion. The reforming water outflow pipe 18b has a pointed head 18d formed in a pointed shape on the tip side, and a through hole 18d1 as a second opening is formed in the tip portion. In the reforming water outflow pipe 18b, the through hole 18d1 is disposed adjacent to the raw material pump 11a1 side with respect to the opening 18c1 of the nozzle 18c of the raw material injection pipe 18a.

  Further, as shown in FIG. 2, a needle valve 18e, an O-ring 18f and a needle packing 18g as shaft-like members are accommodated in the reformed water outflow pipe 18b. Further, a needle valve adjusting mechanism 18h as a drive member is assembled on the base end side of the reforming water outflow pipe 18b. The outer dimension of the needle valve adjusting mechanism 18h is set to be smaller than the inner diameter of the raw material injection pipe 18a.

  The needle valve 18e is provided so as to be movable along the axial direction of the reforming water outflow pipe 18b. The distal end portion 18e1 of the needle valve 18e is formed in a pointed shape, and the proximal end portion 18e2 is connected to the needle valve adjusting mechanism 18h. Thus, the needle valve 18e is advanced by the needle valve adjusting mechanism 18h so as to approach the through hole 18d1 of the reforming water outflow pipe 18b along the axial direction of the reforming water outflow pipe 18b and from the through hole 18d1. The vehicle moves backward so as to be separated. The needle valve 18e moves forward or backward (advances / retreats) with respect to the through hole 18d1, and is formed by the outer peripheral surface of the tip end portion 18e1 and the inner peripheral surface of the through hole 18d1, and the flow path cross-sectional area of the flow path through which the reforming water flows. Change the size (opening). Thereby, the needle valve 18e adjusts the supply amount of the reforming water flowing out from the through hole 18d1.

  Further, as shown in FIG. 3, the needle valve 18e advances toward the through hole 18d1, and the outer peripheral surface of the tip 18e1 and the inner peripheral surface of the through hole 18d1 are brought into close contact with each other, whereby the needle valve 18e is modified from the through hole 18d1. Prohibit (stop) the flow of water. As will be described later, the needle valve 18e is configured such that the advance amount or the reverse amount is linearly controlled by a needle valve adjusting mechanism 18h. Accordingly, the needle valve 18e is a linear valve, and is formed by the outer peripheral surface of the tip end portion 18e1 and the inner peripheral surface of the through hole 18d1, and linearly changes the cross-sectional area (opening degree) through which the reforming water passes. The supply amount of reforming water can be adjusted linearly.

  Returning to FIG. 2 again, the O-ring 18f and the needle packing 18g prevent the reforming water in the reforming water outflow pipe 18b from leaking from the base end side (needle valve adjusting mechanism 18h) of the reforming water outflow pipe 18b. To do. For this reason, as shown in FIG. 2, the O-ring 18f and the needle packing 18g are located more than the connection position between the reforming water outflow pipe 18b and the reforming water supply pipe 11b (substantially the central portion of the reforming water outflow pipe 18b). It is juxtaposed on the base end side.

  The needle valve adjusting mechanism 18h moves the needle valve 18e along the axial direction. The needle valve adjusting mechanism 18h is electrically connected to the control device 16 (see FIG. 1), and is operated based on a command from the control device 16 to adjust the advance amount or reverse amount of the needle valve 18e. Thus, the supply amount of the reforming water is adjusted. The needle valve adjusting mechanism 18h is, for example, a solenoid, and an instruction current value (for example, a current value corresponding to the target supply amount) set in advance so as to correspond to a desired flow path cross-sectional area (opening) is a control device. The needle valve 18e is moved forward or backward by being supplied from 16 and operated.

  The operation of the raw material / water mixing adjuster 18 will be described. When the fuel cell module 11 is activated, the raw material pump 11a1 (reforming raw material supply device) is activated, and the raw material pump 11a1 pumps the reforming raw material from the supply source Gs into the reforming raw material supply pipe 11a. The reforming raw material pumped into the reforming raw material supply pipe 11a flows in the raw material injection pipe 18a of the raw material / water mixing adjuster 18, and the flow is throttled by the nozzle 18c to increase the flow velocity, thereby opening the opening. 18c1 is injected into the mixed gas supply pipe 11f.

  As described above, the through-hole 18d1 of the reforming water outflow pipe 18b is connected to the nozzle 18c on the side of the raw material pump 11a1, that is, inside the raw material injection pipe 18a, with respect to the opening 18c1 of the nozzle 18c of the raw material injection pipe 18a. It is adjacent inside. In this case, when the reforming raw material increases the flow rate and passes through the periphery of the through hole 18d1 of the reforming water outflow pipe 18b and is injected from the opening 18c1, the pressure around the through hole 18d1 adjacent to the opening 18c1 is increased. Decreases. For this reason, the reforming water present in the reforming water outflow pipe 18b is sucked out from the through hole 18d1 as the pressure decreases. That is, the reforming water present in the reforming water outflow pipe 18b is continuously sucked out without the need for pressurization as the reforming raw material is injected through the nozzle 18c.

  Incidentally, a needle valve 18e, which is a shaft-like member, is provided inside the reforming water outflow pipe 18b so as to be movable along the axial direction of the reforming water outflow pipe 18b. Further, the needle valve 18e is moved forward or backward so as to change the flow passage cross-sectional area (opening degree) of the reforming water in the through hole 18d1 by the needle valve adjusting mechanism 18h controlled by the control device 16. Thereby, the needle valve 18e and the needle valve adjusting mechanism 18h can appropriately adjust the supply amount (supply flow rate) of the reforming water supplied from the reforming water outflow pipe 18b. Here, the supply amount (supply flow rate) is a flow rate of reformed water to be supplied, and is a flow rate per unit time.

  Specifically, for example, the control device 16 acquires the magnitude of the power consumption of the external power load 17c, and corresponds to the magnitude of the acquired power consumption by referring to the map (or formula) shown in FIG. The supply amount of reforming water is determined as the target supply amount. As described above, the needle valve 18e can change linearly the flow passage cross-sectional area in the through hole 18d1, that is, the supply amount of reforming water, by moving forward or backward. For this reason, the control device 16 is associated in advance so as to realize the cross-sectional area of the flow path, that is, the advance amount (or reverse amount) of the needle valve 18e and this advance amount (or reverse amount). The magnitude of the command current is determined based on the relationship with the current supplied to the solenoid. Then, the control device 16 supplies a command current corresponding to the advance amount or the reverse amount of the needle valve 18e for realizing the flow path cross-sectional area corresponding to the target supply amount to the needle valve adjustment mechanism 18h.

  Here, for example, the control device 16 controls the flow rate of the reforming raw material pumped by the raw material pump 11a1 and the pressure sensor 32a serving as a physical quantity detection unit provided in the reforming unit 32 described later from the reforming unit 32. The pressure as a physical quantity representing the internal state is acquired, and the target supply amount can be corrected based on these flow rate and pressure. The pressure sensor 32 a transmits the detected pressure to the control device 16.

  In this case, the flow rate of the reforming raw material is related to the pressure drop generated by the flow of the reforming raw material through the nozzle 18c. The lower the flow rate, the smaller the generated pressure drop. That is, in this case, since the supply amount of the reforming water flowing out from the reforming water outflow pipe 18b decreases, the control device 16 corrects the flow path cross-sectional area so that the correction amount increases. Conversely, as the flow rate increases, the pressure drop increases and the supply amount of reforming water flowing out from the reforming water outflow pipe 18b increases. Therefore, the controller 16 reduces the flow path cross-sectional area so that the correction amount decreases. to correct.

  The internal pressure of the reforming unit 32 is such that the amount of mixed gas supplied from the raw material / water mixing regulator 18 and the amount of water vapor generated when the reformed water contained in the supplied mixed gas is vaporized. In relation to the amount, the higher the pressure, the smaller the amount of gas mixture supplied and the amount of water vapor generated. In particular, when the amount of generated water vapor decreases, carbon deposition (coking) may occur in a catalyst or the like disposed inside the reforming section 32 as will be described later. Therefore, when the internal pressure of the reforming unit 32 is higher than the reference pressure, the control device 16 corrects the target supply amount (that is, the flow path cross-sectional area) so that the correction amount becomes large, for example. On the contrary, when the pressure inside the reforming unit 32 is lower than the reference pressure, the control device 16 corrects the target supply amount (that is, the flow path cross-sectional area) so that the correction amount becomes small, for example.

  In the needle valve adjusting mechanism 18h, the needle valve 18e is moved forward or backward so as to have a flow path cross-sectional area that realizes the target supply amount in accordance with the supplied command current. Thereby, the reformed water corresponding to the adjusted channel cross-sectional area (opening degree) is sucked out, and becomes a mixed gas in which the reforming raw material and the reformed water are mixed. Here, the sucked-in reforming water is injected into the mixed gas supply pipe 11f from the opening 18c1 of the nozzle 18c of the raw material injection pipe 18a together with the reforming raw material having a large flow rate. At this time, the granular reforming water is pulverized by the injection force of the reforming raw material being pumped, and is atomized together with the reforming raw material in the mixed gas supply pipe 11f, and is supplied to the reforming unit 32 as a mixed gas. Is done.

  In the mixed gas supplied to the reforming section 32, it is preferable that the flow rate ratio is adjusted so that the reforming raw material and the reforming water are equal. Further, in the fuel cell system 1, when the reforming water is stopped from the reforming water outflow pipe 18b, as shown in FIG. 3, the inside of the outer peripheral surface of the needle valve 18e and the through hole 18d1 of the reforming water outflow pipe 18b. This is realized by closing the through-hole 18d1 in close contact with the peripheral surface.

  Returning again to FIG. 1, the fuel cell module 11 (30) includes a casing 31, a reforming unit 32, and a fuel cell 33. The casing 31 is formed in a box shape with a heat insulating material. A reforming section 32 and a fuel cell 33 are accommodated in the casing 31.

  The reforming unit 32 is heated by a combustion gas to be described later and supplied with heat necessary for the steam reforming reaction, so that the mixed gas (reforming raw material and steam) supplied from the raw material / water mixing controller 18 is supplied. The reformed gas is generated and derived from the gas. The reforming unit 32 is filled with a catalyst (for example, Ru or Ni-based catalyst), and the mixed gas reacts with the catalyst to be reformed to generate a gas containing hydrogen gas and carbon monoxide. (So-called steam reforming reaction). The reformed gas contains hydrogen, carbon monoxide, carbon dioxide, steam, unreformed natural gas (methane gas), and reformed water (steam) that has not been used for reforming. As described above, the reforming unit 32 generates reformed gas (fuel) from the reforming raw material (raw fuel) and the reformed water, and supplies the reformed gas to the fuel cell 33. The steam reforming reaction is an endothermic reaction.

  The fuel cell 33 is configured by laminating a fuel electrode, an air electrode (oxidant electrode), and a plurality of cells 33a made of an electrolyte interposed between the two electrodes. The fuel cell of this embodiment is a solid oxide fuel cell, and uses zirconium oxide, which is a kind of solid oxide, as an electrolyte. Hydrogen, carbon monoxide, methane gas or the like is supplied to the fuel electrode of the fuel cell 33 as fuel. The operating temperature is about 400-1000 ° C.

  On the fuel electrode side of the cell 33a, a fuel flow path 33b through which a reformed gas that is a fuel flows is formed. An air flow path 33c through which air (cathode air) that is an oxidant gas flows is formed on the air electrode side of the cell 33a.

  The fuel cell 33 is provided on the manifold 34. A reformed gas (anode gas) from the reforming unit 32 is supplied to the manifold 34 via a reformed gas supply pipe 37. The lower end (one end) of the fuel flow path 33b is connected to the fuel outlet of the manifold 34, and the reformed gas led out from the fuel outlet is introduced from the lower end and led out from the upper end. . The cathode air sent out by the cathode air blower 11c1 is supplied via the cathode air supply pipe 11c, is introduced from the lower end of the air flow path 33c, and is led out from the upper end.

In the fuel cell 33, power generation is performed by the reformed gas (anode gas) supplied to the fuel electrode and the oxidant gas (cathode gas) supplied to the air electrode. That is, the reaction shown in Chemical Formula 1 and Chemical Formula 2 below occurs at the fuel electrode, and the reaction shown in Chemical Formula 3 below occurs at the air electrode. Specifically, oxide ions (O ²⁻ ) generated at the air electrode permeate the electrolyte and react with hydrogen at the fuel electrode to generate electrical energy. Then, the reformed gas and the oxidant gas (air) that have not been used for power generation are derived from the fuel flow path 33b and the air flow path 33c.
(Chemical formula 1)
H ₂ + O ²⁻ → H ₂ O + 2e ⁻
(Chemical formula 2)
CO + O ²⁻ → CO ₂ + 2e ⁻
(Chemical formula 3)
1 / 2O ₂ + 2e ⁻ → O ²⁻

  Then, the reformed gas (anode off gas) that has not been used for power generation is led out from the fuel flow path 33b to the combustion section 35 (a space formed between the fuel cell 33 and the reforming section 32). Oxidant gas (air: cathode off gas) that has not been used for power generation is led to the combustion section 35 from the air flow path 33c. The anode off gas is combusted by the cathode off gas in the combustion unit 35, and the reforming unit 32 is heated by the combustion gas. Furthermore, the fuel cell module 11 is heated to the operating temperature by the combustion gas. Thereafter, the combustion gas is exhausted out of the fuel cell module 11 as combustion exhaust gas from an exhaust pipe 11d provided at the lower portion of the casing 12b. In this way, the combustion unit 35 introduces the fuel off-gas (anode off-gas) that is unused fuel (reformed gas) from the fuel cell 33 and burns with the oxidant gas to derive combustion exhaust gas (including water vapor). It is a combustion part. That is, the combustion unit 35 is a combustion unit that derives combustion exhaust gas by burning the combustion off gas and the oxidant gas from the fuel cell 33.

  In the combustion unit 35, the anode off-gas is burned and a flame 36 (combustion exhaust gas) is generated. The combustion unit 35 is provided with a pair of ignition heaters 35a1 and 35a2 for igniting the anode off gas.

  As can be understood from the above description, the fuel cell system 1 of the present embodiment generates fuel from the fuel cell 33 that generates power using fuel and oxidant gas, the reforming raw material, and reformed water. The reformer 32 that supplies fuel to the battery 33, the combustion unit 35 that burns fuel off-gas and oxidant gas from the fuel cell 33 to derive combustion exhaust gas, and the reforming material supply source Gs are connected. The reforming material supply pipe 11a is provided with a raw material pump 11a1 as a reforming raw material supply device that pumps the reforming raw material from the supply source Gs to the reforming unit 32, and the steam contained in the combustion exhaust gas. Heat exchanger 12 as a condenser that condenses to produce condensed water, and is disposed above reforming section 32 and below heat exchanger 12, and the condensed water supplied from heat exchanger 12 is used as reforming water. A reforming water tank 15 for storing water and a reforming water tank A reforming water supply pipe 11b that is connected to the reforming water 15 and drops the reforming water in the reforming water tank 15 by its own weight and supplies it to the reforming unit 32, and a control device that controls the power generation of the fuel cell 33 in an integrated manner. 16, and a nozzle 18c that is connected to the reforming raw material supply pipe 11a and directed toward the reforming unit 32, and supplies the reforming raw material that has been fed under pressure to the reforming unit. Adjacent to the raw material pump 11a1 side with respect to an opening portion 18c1 as a first opening which is connected to the raw material injection pipe 18a for injecting the gas 32 and the reforming water supply pipe 11b and which is an opening of the nozzle 18c of the raw material injection pipe 18a. A reforming water outflow pipe 18b for flowing out the reforming water at the position, and provided inside the reforming water outflow pipe 18b so as to be movable along the axial direction of the reforming water outflow pipe 18b. Is the opening of the reforming water outflow pipe 18b Advancing and retreating with respect to the through hole 18d1 as the second opening, the flow passage cross-sectional area of the flow passage formed by the outer peripheral surface of the tip end portion 18e1 and the inner peripheral surface of the through hole 18d1 through which the reforming water passes is changed. A needle valve 18e as a shaft-like member, and a needle valve adjustment mechanism 18h as a drive member that is connected to the base end portion 18e2 of the needle valve 18e and moves the needle valve 18e along the direction of the axis. The raw material / water mixing adjuster 18 is provided as a mixing unit, and the raw material / water mixing adjuster 18 is connected to the reforming raw material and the reforming water outflow pipe 18b whose flow velocity is increased by the nozzle 18c of the raw material injection pipe 18a. The supplied reforming water is mixed and supplied to the reforming unit 32.

  According to this, in the fuel cell system 1, when the reforming raw material pumped by the raw material pump 11a1 passes through the nozzle 18c of the raw material injection pipe 18a and the flow velocity increases, the vicinity of the opening 18c1 of the nozzle 18c, That is, the pressure of the portion where the through hole 18d1 of the reforming water outflow pipe 18b is located is lowered, and the reforming water is sucked out from the through hole 18d1 of the reforming water outflow pipe 18b. Thereby, in the fuel cell system 1, it is not necessary to pressurize and supply reforming water, and the reforming water pump provided in the conventional fuel cell system can be omitted. Therefore, the fuel cell system 1 can reduce the manufacturing cost as compared with the conventional fuel cell system.

  Further, in the raw material / water mixing adjuster 18, the needle valve 18e is formed by the cross-sectional area of the flow path, that is, the outer peripheral surface at the tip end portion 18e1 of the needle valve 18e and the inner peripheral surface of the through hole 18d1 of the reforming water outflow pipe 18b. Since the cross-sectional area of the reformed water channel can be changed, the supply amount (flow rate) of the reformed water supplied to the reforming unit 32 can be adjusted. Therefore, the raw material / water mixing adjuster 18 can supply the reformed portion 32 with the mixed gas in which the reforming raw material and the reformed water are adjusted.

  Further, in the fuel cell system 1, the needle valve adjustment mechanism 18h is operated only when the supply amount (flow rate) of the reforming water is changed by moving the needle valve 18e in the axial direction by the raw material / water mixing regulator 18. Therefore, power consumption can be extremely reduced. Thereby, the fuel cell system 1 can prevent the power generation efficiency from being lowered.

  Further, in the fuel cell system 1, since the mixed gas in which the reforming raw material and the reforming water are accurately adjusted can be supplied to the reforming unit 32, the reforming unit 32 is necessary and sufficiently modified. Quality water can be supplied. Thereby, it is possible to prevent the occurrence of water vapor shortage (reformed water shortage) in the reforming unit 32, and it is possible to suppress the occurrence of carbon deposition (coking) in the reforming unit 32.

  Furthermore, in the fuel cell system 1, the evaporation part provided in the conventional fuel cell system can be omitted. As a result, the fuel cell system 1 can reduce the manufacturing cost and realize downsizing as compared with the conventional fuel cell system.

  In this case, the reforming water outflow pipe 18b has an outer diameter smaller than the inner diameter of the raw material injection pipe 18a and is coaxially arranged inside the raw material injection pipe 18a. The vessel 18 can be composed of a double tube.

  According to this, the reforming water outflow pipe 18b can be arranged inside the raw material injection pipe 18a and the raw material / water mixing adjuster 18 can have a double pipe structure, so that space saving can be realized. it can. As a result, the fuel cell system 1 can be downsized.

  In these cases, as a physical quantity representing the internal state of the reforming section 32, a pressure sensor as a physical quantity detection section that detects a pressure that is at least one of pressure, humidity, and temperature inside the reforming section 32. 32a, and the control device 16 corrects the target supply amount of the reformed water supplied from the reforming water outflow pipe 18b using the pressure detected by the pressure sensor 32a, and the needle is based on the corrected target supply amount. It is possible to change the flow path cross-sectional area by controlling the operation of the valve adjusting mechanism 18h and moving the needle valve 18e along the axial direction.

  According to this, the control device 16 controls the operation of the needle valve adjusting mechanism 18h so that the supply amount of the reforming water supplied from the reforming water outlet pipe 18b becomes the target supply amount, that is, the needle valve 18e. It is possible to precisely change the cross-sectional area of the flow path changed by. Therefore, the raw material / water mixing adjuster 18 can supply the reforming unit 32 with a mixed gas in which the reforming raw material and the reformed water are accurately adjusted.

  Further, the pressure, which is a physical quantity representing the internal state of the reforming unit 32 to which the mixed gas is supplied from the raw material / water mixing regulator 18, can be detected, and the control device 16 supplies the target based on the detected pressure. The quantity (i.e., channel cross-sectional area) can be determined. As a result, the amount of reformed water supplied can be adjusted extremely accurately and precisely, and the reformed water that has become mist-like reformed water or steam with respect to the reformer 32 can be reliably mixed gas. Can be supplied. Therefore, it is possible to prevent the steam shortage (reforming water shortage) from occurring in the reforming unit 32, and to suppress the occurrence of carbon deposition (coking) in the reforming unit 32.

  Further, in these cases, the raw material / water mixing adjuster 18 can stop the supply of the reforming water by the tip 18e1 of the needle valve 18e closing the through hole 18d1 of the reforming water outflow pipe 18b. Thereby, supply of reforming water can be stopped with a very simple structure.

(First modification of embodiment)
In the above embodiment, the raw material / water mixing adjuster 18 has a double pipe structure in which the reforming water outflow pipe 18b is arranged inside the raw material injection pipe 18a. And the through-hole 18d1 of the reforming water outflow pipe 18b is arranged on the raw material pump 11a1 side with respect to the opening 18c1 of the nozzle 18c of the raw material injection pipe 18a. Instead, as shown in FIG. 5, the reforming water outflow pipe 18b is arranged so as to be substantially orthogonal to the direction of the axis of the raw material injection pipe 18a, and the through hole 18d1 of the reforming water outflow pipe 18b. However, it is also possible to use the raw material / water mixing adjuster 18 configured to be disposed on the reforming unit 32 side with respect to the opening 18c1 of the nozzle 18c of the raw material injection pipe 18a. In this case, the reforming water outflow pipe 18b is hermetically connected to the mixed gas supply pipe 11f. Further, in this case, unlike the above embodiment, the reforming water outflow pipe 18b is provided with a reservoir 18i for temporarily storing the reforming water, and the O-ring 18f and the needle packing 18g are omitted.

  Also in this first modification, when the fuel cell module 11 is activated, the raw material pump 11a1 (reforming raw material supply device) is operated, and the raw material for reforming is supplied from the supply source Gs by the raw material pump 11a1. 11a is pumped. The reforming raw material pumped into the reforming raw material supply pipe 11a flows in the raw material injection pipe 18a of the raw material / water mixing adjuster 18, and the flow is throttled by the nozzle 18c to increase the flow velocity, thereby opening the opening. 18c1 is injected into the mixed gas supply pipe 11f.

  In the first modification, the through hole 18d1 of the reforming water outlet pipe 18b is adjacent to the opening 18c1 of the nozzle 18c of the raw material injection pipe 18a on the reforming part 32 side. Also in this case, when the reforming raw material increases the flow rate and passes through the periphery of the through hole 18d1 of the reforming water outflow pipe 18b and is injected from the opening 18c1, the periphery of the through hole 18d1 adjacent to the opening 18c1 The pressure at decreases. For this reason, the reforming water present in the reforming water outflow pipe 18b is sucked out from the through hole 18d1 as the pressure decreases, as in the above embodiment. That is, also in this first modified example, the reforming water existing in the reforming water outflow pipe 18b is injected by the reforming raw material passing through the nozzle 18c without requiring pressurization. Is continuously sucked out.

  Also in this first modified example, a needle valve 18e, which is a shaft-like member, is provided inside the reforming water outflow pipe 18b so as to be movable along the axial direction of the reforming water outflow pipe 18b. . The needle valve 18e can be moved forward or backward so as to change the cross-sectional area (opening degree) of the reforming water in the through hole 18d1 by the needle valve adjusting mechanism 18h controlled by the control device 16. Thereby, the needle valve 18e and the needle valve adjusting mechanism 18h can appropriately adjust the supply amount of the reforming water supplied from the reforming water outflow pipe 18b so as to become the target supply amount. Therefore, also in this first modified example, the same effect as in the above embodiment can be obtained.

(Second modification of the embodiment)
In the above embodiment, when the supply of reforming water from the reforming water outflow pipe 18b is stopped, as shown in FIG. 3, the outer peripheral surface of the needle valve 18e and the through hole 18d1 of the reforming water outflow pipe 18b are provided. The through hole 18d1 was closed by closely contacting the inner peripheral surface. Instead, as shown in FIG. 6, for example, a sealing valve 18e3 having a radially expanded diameter is provided on the outer peripheral surface of the needle valve 18e, and the sealing valve 18e3 is provided inside the nozzle 18c of the raw material injection pipe 18a. It is also possible to provide a valve seat 18a1 that abuts. Here, the inner diameter of the valve seat 18a1 is set to be larger than the outer diameter of the needle valve 18e. Thereby, the outer peripheral surface of the needle valve 18e and the inner peripheral surface of the valve seat 18a1 do not come into contact with each other, and no friction is generated between the outer peripheral surface of the needle valve 18e and the inner peripheral surface of the valve seat 18a1. ing.

  In this case, the supply of the reforming water from the through hole 18d1 of the reforming water outflow pipe 18b can be stopped by the sealing valve 18e3 provided in the needle valve 18e sitting on the valve seat 18a1. Further, the sealing valve 18e3 provided in the needle valve 18e is separated from the valve seat 18a1, so that the reforming water can be supplied from the through hole 18d1 of the reforming water outflow pipe 18b. Therefore, also in this second modified example, the same effect as in the above embodiment can be obtained.

  In carrying out the present invention, the present invention is not limited to the above-described embodiments and modifications, and various modifications can be made without departing from the object of the present invention.

  For example, in the above embodiment, the raw material / water mixing adjuster 18 is provided outside the casing 31 of the fuel cell module 11 (30). That is, in the above embodiment, the raw material / water mixing adjuster 18 supplies the mixed gas to the reforming unit 32 via the mixed gas supply pipe 11f. Alternatively, the raw material / water mixing adjuster 18 may be configured to supply the mixed gas directly into the reforming unit 32. That is, in this case, the raw material / water mixing adjuster 18 is provided inside the casing 31, and the raw material / water mixing adjuster 18 supplies the mixed gas directly to the reforming unit 32 in the combustion unit 35. To do. Thereby, the mixed gas supply pipe 11f can be omitted, the manufacturing cost can be further reduced, and the downsizing can be achieved. When the raw material / water mixing regulator 18 is arranged in the casing 31 (combustion part 35) in this way, the reforming water supply pipe 11b that has entered the combustion part 35 from the upper part of the casing 31 and the raw material / water The reforming water outflow pipe 18b of the mixing adjuster 18 is connected. Thereby, the influence of the heat with respect to the reforming water supplied from the reforming water tank 15 can be eliminated as much as possible.

  In the above embodiment, a solenoid is used for the needle valve adjusting mechanism 18h. Instead of this, it is also possible to use, for the needle valve adjusting mechanism 18h, a motor or the like that generates power that can move the needle valve 18e forward or backward. In this case, in particular, when a motor is used for the needle valve adjusting mechanism 18h, it is preferable to bend the raw material injection pipe 18a and arrange the motor outside the raw material injection pipe 18a. As described above, by disposing the needle valve adjustment mechanism 18h outside the raw material injection pipe 18a, the flow of the reforming raw material is not hindered by the needle valve adjustment mechanism 18h, and the reforming raw material is inside the raw material injection pipe 18a. Can flow smoothly.

  In addition, a pressure sensor 32a is provided inside the reforming unit 32 as a physical quantity detection unit, and the pressure inside the reforming unit 32 is detected as a physical quantity. In addition to this, or instead of this, a humidity sensor or a temperature sensor is provided as a physical quantity detection unit inside the reforming unit 32, and the humidity or temperature inside the reforming unit 32 is detected as a physical quantity. good. As a result, the control device 16 can determine and correct the target supply amount (channel cross-sectional area) more accurately using the detected humidity and temperature inside the reforming unit 32.

  In the above embodiment, only the raw material / water mixing adjuster 18 supplies the reformed portion 32 with the mixed gas composed of the raw material for reforming and the reforming water. In this case, in addition to the raw material / water mixing adjuster 18, an evaporation unit as provided in the conventional fuel cell system is provided, and during normal operation, the evaporation unit is passed through like the conventional fuel cell system. It is also possible to use a normal line for supplying the mixed gas to the reforming section 32. In addition to the normal line, by providing a backup line that is supplied via the raw material / water mixing regulator 18 as described above, the fuel cell system 1 can be configured by using the backup line even when the normal line fails. It is also possible to ensure that it is activated.

  Furthermore, when the control device 16 determines the target supply amount, it is possible to correct the target supply amount according to the amount of reforming water stored in the reforming water tank 15. Specifically, the control device 16 can acquire the detection result of the water amount sensor 15a and correct the target supply amount so that the correction amount increases as the detected water amount decreases, for example. Here, the correction amount can be calculated as a value corresponding to the detected water amount by using a map or a mathematical expression showing the relationship between the detected water amount and the correction amount that is calculated and stored in advance by experiments or the like. Since the amount of water falling from the reforming water tank 15 is smaller as the tank water amount is smaller, the relationship between the detected water amount and the correction amount is such that the correction amount decreases as the detected water amount increases.

DESCRIPTION OF SYMBOLS 1 ... Fuel cell system, 10 ... Power generation unit, 10a ... Housing, 11 ... Fuel cell module, 11a ... Reforming raw material supply pipe, 11a1 ... Raw material pump, 11b ... Reformed water supply pipe, 11c ... Cathode air supply pipe 11c1 ... Cathode air blower, 11d ... Exhaust pipe, 11e ... Drain pipe, 11f ... Mixed gas supply pipe, 12 ... Heat exchanger, 12a ... Condensed water supply pipe, 12b ... Casing, 12c ... Heat exchange section, 13 ... Inverter Equipment, 14 ... water purifier, 15 ... reformed water tank, 15a ... water quantity sensor, 16 ... control device, 17a ... system power supply, 17b ... power line, 17c ... external power load, 18 ... raw material / water mixing regulator ( Mixing part), 18a ... Raw material injection pipe, 18a1 ... Valve seat, 18b ... Reformed water outflow pipe, 18c ... Nozzle, 18c1 ... Opening (first opening), 18d ... Pointed head, 18d1 ... Through (Second opening), 18e ... needle valve, 18e1 ... tip, 18e2 ... base end, 18e3 ... sealing valve, 18f ... O-ring, 18g ... needle packing, 18h ... needle valve adjustment mechanism (drive member), 18i DESCRIPTION OF SYMBOLS ... Storage part, 20 ... Waste heat recovery system, 21 ... Hot water tank, 22 ... Hot water circulation line, 22a ... Hot water circulation pump, 22b ... Heat exchanger hot water inlet temperature sensor, 22c ... Heat exchanger hot water outlet temperature sensor, DESCRIPTION OF SYMBOLS 31 ... Casing, 32 ... Reforming part, 32a ... Pressure sensor (physical quantity detection part), 33 ... Fuel cell, 33a ... Cell, 33b ... Fuel flow path, 33c ... Air flow path, 34 ... Manifold, 35 ... Combustion part, 35a1, 35a2 ... ignition heater, 36 ... flame, 37 ... reformed gas supply pipe, Gs ... supply source

Claims (5)

A fuel cell that generates electricity using fuel and oxidant gas;
A reforming unit that generates the fuel from a reforming raw material and reforming water and supplies the fuel to the fuel cell;
A combustion unit for deriving combustion exhaust gas by burning a fuel off-gas and an oxidant gas from the fuel cell;
A reforming material supply device that is provided in a reforming material supply pipe connected to the reforming material supply source and pumps the reforming material from the supply source to the reforming unit;
A condenser that condenses water vapor contained in the combustion exhaust gas to generate condensed water;
A reforming water tank disposed above the reforming unit and below the condenser and storing the condensed water supplied from the condenser as the reforming water;
A reforming water supply pipe connected to the reforming water tank and dropping the reforming water in the reforming water tank by its own weight and supplying the reforming section;
A fuel cell system comprising: a control device that performs overall control of power generation of the fuel cell;
A raw material injection pipe that is connected to the reforming raw material supply pipe and has a nozzle directed to the reforming section, and injects the reformed raw material that has been pumped into the reforming section;
Connected to the reforming water supply pipe and at a position adjacent to the reforming raw material supply apparatus side or the reforming section side with respect to the first opening which is the opening of the nozzle of the raw material injection pipe A reforming water outflow pipe for flowing out the reforming water;
It is provided inside the reforming water outflow pipe so as to be movable along the direction of the axis of the reforming water outflow pipe, and its tip part advances and retreats with respect to a second opening which is an opening of the reforming water outflow pipe. A shaft-shaped member that is formed by the outer peripheral surface of the tip portion and the inner peripheral surface of the second opening and that changes the cross-sectional area of the flow channel through which the reforming water passes,
A driving member connected to a base end portion of the shaft-shaped member and moving the shaft-shaped member along the direction of the axis,
The mixing unit mixes the reforming raw material whose flow velocity is increased by the nozzle of the raw material injection pipe and the reforming water supplied from the reforming water outflow pipe, and supplies the mixture to the reforming unit. A fuel cell system configured as described above. The reformed water outflow pipe is
2. The fuel cell system according to claim 1, wherein the fuel cell system has an outer diameter smaller than an inner diameter of the raw material injection pipe and is coaxially disposed inside the raw material injection pipe. A physical quantity detection unit for detecting a physical quantity representing an internal state of the reforming unit;
The control device includes:
Correcting the target supply amount of the reformed water supplied from the reforming water outflow pipe using the physical quantity detected by the physical quantity detection unit;
The operation of the drive member is controlled based on the corrected target supply amount, and the flow path cross-sectional area is changed by moving the shaft-shaped member along the direction of the axis. Fuel cell system. The physical quantity is
The fuel cell system according to claim 3, wherein the fuel cell system is at least one of pressure, humidity, and temperature inside the reforming unit. The mixing unit includes:
The said front-end | tip part of the said shaft-shaped member blocks the said 2nd opening of the said reforming water outflow pipe, and stops supply of the said reforming water as described in any one of Claim 1 thru | or 4. Fuel cell system.

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