JP2012219008A - Thermal treatment system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To excellently control the loss of a heat energy from a combustor and aim to promote heat independence, thereby miniaturizing a system and reducing a cost.SOLUTION: Both ends of a plurality of oxidizer gas conduits 78 communicate to an oxidizer gas supply chamber 76a and an oxidizer gas discharging chamber 76b constituting a heat exchanger 50. A combustion chamber 84 comprising space where the plurality of the oxidizer gas conduits 78 are housed is formed inside the heat exchanger 50. One end of an oxidizing agent exhaust gas supply tube 86 and one end of a fuel exhaust gas supply tube 88 are disposed from the oxidizer gas discharging chamber 76b side in a combustion chamber 84. The tube length in which the fuel exhaust gas outlet 88a side of the fuel exhaust gas supply tube 88 projects inside the combustion chamber 84 is constituted longer than the tube length in which the oxidizing agent exhaust gas outlet 86a side of the oxidizing agent exhaust gas supply tube 86 projects inside the combustion chamber 84.

Description

  The present invention relates to a heat treatment system including a heat exchanger for heating a fluid.

  Usually, a heat treatment system including a heat exchanger for heating a fluid is used as a peripheral device of a solid oxide fuel cell (SOFC). This fuel cell uses an oxide ion conductor, for example, stabilized zirconia, as a solid electrolyte, and an electrolyte / electrode assembly (hereinafter also referred to as MEA) in which an anode electrode and a cathode electrode are disposed on both sides of the solid electrolyte. ) Is sandwiched between separators (bipolar plates). This fuel cell is normally used as a fuel cell stack in which a predetermined number of electrolyte / electrode assemblies and separators are laminated.

  In a heat treatment system, in general, a raw fuel mainly composed of hydrocarbon is reformed, and an oxidant gas is increased by heat exchange between a reformer that generates fuel gas supplied to a fuel cell stack and a combustion gas. A heat exchanger for supplying the oxidant gas to the fuel cell stack, and burning the fuel exhaust gas as the fuel gas and the oxidant exhaust gas as the oxidant gas discharged from the fuel cell stack. An exhaust gas combustor for generating the combustion gas is provided.

  For example, the fuel cell system disclosed in Patent Document 1 includes a combustor 1 as shown in FIG. The combustor 1 includes a combustion chamber 2 having a casing, a fuel off-gas supply pipe 3 having one end connected to an exhaust pipe on the fuel electrode side of the cell stack and the other end disposed inside the combustion chamber 2. One end of the fuel off-gas supply pipe 3 is opposed to the other end of the fuel off-gas supply pipe 3 at a predetermined distance from the other end, and the other end is led out of the combustion chamber 2 so that an exhaust device or other fuel recycle device is provided. And the other end of the fuel exhaust pipe 4 connected to the air electrode side exhaust pipe of the cell stack, the axis of which is perpendicular to the axis of the fuel off-gas supply pipe 3, and the fuel An oxidant off-gas supply pipe 5 disposed inside the combustion chamber 2 so as to open toward a region between the other end of the off-gas supply pipe 3 and one end of the fuel exhaust pipe 4, and one end of the combustion. The chamber 2 is disposed at a position away from the combustion area and the interference area. The other end and an oxidant exhaust pipe 6 connected to a mechanism for high-temperature holding the derived reformer and the cell stack to the outside of the combustion chamber 2.

JP 2010-277876 A

  In the above-mentioned Patent Document 1, the fuel off-gas supply pipe 3 and the oxidant off-gas supply pipe 5 are arranged orthogonally to the inside of the combustion chamber 2, and the axis of the fuel off-gas supply pipe 3 and the oxidant off-gas are arranged. Only the intersection with the axis of the supply pipe 5 is the ignition point. For this reason, a combustion position cannot be controlled and there exists a possibility of backfire by flame propagation etc., for example. In addition, inside the combustion chamber 2, there is a problem that the central portion becomes high temperature, but the end portion is hardly heated, and the difference in temperature distribution becomes large.

  The present invention solves this type of problem, and in particular, provides a heat treatment system that can suppress heat energy loss well, promote thermal independence, and can be reduced in size and cost. Objective.

  The present invention relates to a heat treatment system including a heat exchanger for heating a fluid.

  In this heat treatment system, the heat exchanger is provided in the heat exchanging part having a plurality of fluid passages for circulating a fluid and in the heat exchanging part, and circulates through each fluid passage by a combustion reaction of fuel gas and oxidant gas. A combustion section that serves as a heat source for raising the temperature of the fluid, a fluid supply chamber that is provided on the upstream side of the heat exchange section, and that supplies the fluid evenly to the fluid passages; and a downstream of the heat exchange section A fuel gas supply pipe provided on the side and having a fluid discharge chamber for discharging the fluid from each of the fluid passages uniformly and a fuel gas outlet communicating with the combustion section and supplying the fuel gas to the combustion section And an oxidant gas supply pipe having an oxidant gas outlet that communicates with the combustion part and supplies the oxidant gas to the combustion part.

  And, the length of the pipe line in which the fuel gas outlet side of the fuel gas supply pipe projects into the combustion part is longer than the pipe length in which the oxidant gas outlet side of the oxidant gas supply pipe projects into the combustion part. Yes.

  In this heat treatment system, the fuel gas supply pipe and the oxidant gas supply pipe are preferably arranged in parallel to each other. For this reason, the combustion range can be spread over the whole area in the combustion part, the temperature distribution in the combustion part becomes small, and the fluid flowing through each fluid passage is heated uniformly.

  Furthermore, in this heat treatment system, it is preferable that the fuel gas supply pipe and the oxidant gas supply pipe are disposed on both sides of the center position with the center position of the combustion portion interposed therebetween. Accordingly, since the combustion range is more reliably spread over the entire combustion part, the temperature distribution in the combustion part becomes as small as possible, and the temperature of the fluid flowing through each fluid passage can be increased evenly.

  Furthermore, in this heat treatment system, it is preferable that a combustion catalyst is provided in the combustion section. As a result, ignitability can be ensured even when a small amount of fuel gas is supplied to the combustion section, and the temperature of the fluid flowing through each fluid passage can be stably increased.

  In this heat treatment system, it is preferable that the fuel gas supply pipe is provided with a slit as a fuel gas outlet for supplying the fuel gas to the combustion section. For this reason, it can suppress that fuel gas burns at a stretch in a combustion part, and does not exceed the heat-resistant temperature of a component, and an improvement in durability is achieved.

  Further, in this heat treatment system, the tip of the fuel gas supply pipe is closed, and a plurality of slits whose opening areas are set small along the direction away from the tip are formed on the outer periphery of the fuel gas supply pipe. Preferably it is formed. Therefore, the fuel gas in the combustion section is not supplied at a stretch, and the flow rate of the fuel gas supplied into the combustion section is evenly distributed along the axial direction of the fuel gas supply pipe. As a result, the combustion range is more reliably spread over the entire combustion section, so that the temperature distribution in the combustion section becomes as small as possible, and the temperature of the fluid flowing through each fluid passage can be increased evenly.

  Furthermore, in this heat treatment system, the heat exchanger is adjacent to a gas combustor for generating combustion gas by a combustion reaction of fuel gas and oxidant gas and supplying the combustion gas to the combustion section. It is preferable to be provided. For this reason, a heat exchange part, a combustion part, and a gas combustor are substantially integrated, and heat dissipation of a heat treatment system can be minimized.

  Therefore, it becomes possible to suppress the loss of heat energy, and the heat independent operation is promoted. Here, the heat self-sustained means that the operating temperature of the fuel cell is maintained only by the heat generated by itself without applying heat from the outside. In addition, since the combustion circuit (piping and the like) is simplified and the number of parts is reduced, the size and cost can be reduced.

  In this heat treatment system, it is preferable that the heat exchanger is provided adjacent to a reformer that reforms raw fuel mainly composed of hydrocarbons and generates fuel gas. As a result, the reformer, the heat exchange unit, and the combustor are substantially integrated, and heat dissipation of the heat treatment system can be minimized. For this reason, it becomes possible to suppress the loss of thermal energy, and the thermal self-sustaining operation is promoted. In addition, since the combustion circuit (piping and the like) is simplified and the number of parts is reduced, the size and cost can be reduced.

  Furthermore, in this heat treatment system, the heat treatment system is combined with a solid oxide fuel cell, and a fuel exhaust gas discharged from the fuel cell as a fuel gas, an oxidant exhaust gas discharged from the fuel cell as an oxidant gas, In addition, an oxidant gas is preferably used as the fluid.

  Therefore, it is most suitable for high-temperature fuel cells such as SOFC (solid oxide fuel cell). In particular, the thermal self-sustaining operation of the SOFC can be promoted.

  According to the present invention, the heat exchange part and the combustion part are integrally provided in the heat exchanger. For this reason, the temperature of the fluid flowing through each fluid passage is efficiently increased, and the heat exchange efficiency is effectively improved.

  In particular, even in a fuel cell having a large A / F (air / fuel gas), the supplied oxidant gas (air) can be effectively heated. Therefore, the heat self-sustaining operation is reliably performed while suppressing the loss of heat energy.

  Further, no piping is required for the heat exchange section and the combustion section. As a result, the combustion circuit (piping, etc.) is simplified and the number of parts is reduced, so that the size and cost can be reduced.

  In addition, a fluid supply chamber is provided on the upstream side of the heat exchanger section, and a fluid discharge chamber is provided on the downstream side of the heat exchange section. Therefore, the fluid can flow evenly along each fluid passage, and the temperature of the fluid can be raised evenly.

  Further, the fuel gas outlet side protrudes into the combustion part from the oxidant gas outlet side. Thereby, when the fluid flows in the direction opposite to the fuel gas (opposite flow), the heat exchange efficiency is further improved. On the other hand, when the fluid flows in the same direction (parallel flow) as the fuel gas, the self-ignition temperature of the fuel gas can be maintained, and misfiring in the combustion part can be avoided.

1 is a schematic configuration explanatory diagram of a fuel cell system incorporating a heat treatment system according to a first embodiment of the present invention. FIG. 3 is a schematic perspective explanatory view of FC peripheral devices constituting the fuel cell system. It is principal part perspective explanatory drawing of the said FC peripheral device. It is a principal part disassembled perspective explanatory drawing of the said FC peripheral device. It is a partial cross section front view of the reformer which comprises the said FC peripheral device. It is a partial cross section front view of the heat exchanger and exhaust gas combustor which comprise the said FC peripheral device. It is a partial cross section side view of the starting gas combustor which comprises the said FC peripheral device. It is a partial cross section front view of the heat processing system which concerns on the 2nd Embodiment of this invention. It is a partial cross section front view of the heat processing system which concerns on the 3rd Embodiment of this invention. 1 is a schematic perspective explanatory view of a fuel cell system disclosed in Patent Document 1. FIG.

  As shown in FIG. 1, the fuel cell system 10 incorporating the heat treatment system according to the first embodiment of the present invention is used for various uses such as in-vehicle use as well as stationary use.

  The fuel cell system 10 includes a fuel cell module (SOFC module) 12 that generates power by an electrochemical reaction between a fuel gas (a gas in which methane and carbon monoxide are mixed in hydrogen gas) and an oxidant gas (air), and the fuel cell. A raw fuel supply device (including a fuel gas pump) 14 for supplying raw fuel (for example, city gas) to the module 12 and an oxidant gas supply device (including an air pump) for supplying the oxidant gas to the fuel cell module 12 ) 16, a water supply device (including a water pump) 18 that supplies water to the fuel cell module 12, and a control device 20 that controls the power generation amount of the fuel cell module 12.

  The fuel cell module 12 includes a solid oxide fuel cell stack (FC stack) 24 in which a plurality of solid oxide fuel cells 22 are stacked in the vertical direction (or horizontal direction). The fuel cell 22 includes, for example, an electrolyte / electrode assembly (MEA) 32 in which a cathode electrode 28 and an anode electrode 30 are provided on both surfaces of an electrolyte 26 made of an oxide ion conductor such as stabilized zirconia.

  On both sides of the electrolyte / electrode assembly 32, a cathode side separator 34 and an anode side separator 36 are disposed. The cathode side separator 34 is formed with an oxidant gas flow path 38 for supplying an oxidant gas to the cathode electrode 28, and the anode side separator 36 is supplied with a fuel gas flow path 40 for supplying fuel gas to the anode electrode 30. Is formed. As the fuel cell 22, various SOFCs conventionally used can be used.

  In the fuel cell stack 24, an oxidant gas inlet communication hole 42 a that communicates integrally with the inlet side of each oxidant gas flow path 38, and an oxidant gas outlet communication that communicates integrally with the outlet side of the oxidant gas flow path 38. A hole 42b, a fuel gas inlet communication hole 44a that communicates integrally with the inlet side of each fuel gas flow path 40, and a fuel gas outlet communication hole 44b that communicates integrally with the outlet side of the fuel gas flow path 40 are provided.

  The fuel cell module 12 reforms a mixed gas of raw fuel (for example, city gas) mainly composed of hydrocarbons and water vapor, and generates a fuel gas to be supplied to the fuel cell stack 24. While evaporating water, the temperature of the oxidant gas is raised by heat exchange with an evaporator 48 that supplies water vapor to the reformer 46 and the combustion gas, and the oxidant gas is supplied to the fuel cell stack 24. A heat exchanger 50, an exhaust gas combustor 52 for burning the fuel exhaust gas as the fuel gas discharged from the fuel cell stack 24 and the oxidant exhaust gas as the oxidant gas, and generating the combustion gas; And a starting gas combustor 54 for generating the combustion gas by combusting raw fuel and the oxidant gas.

  The fuel cell module 12 basically includes a fuel cell stack 24 and an FC peripheral device (heat treatment system according to the first embodiment) 56. The FC peripheral device 56 includes a reformer 46, an evaporator 48, a heat exchanger 50, an exhaust gas combustor (combustion unit) 52, and a start-up gas combustor 54. As will be described later, the reformer 46 The exhaust gas piping is not provided between the heat exchanger 50, the exhaust gas combustor 52, and the starting gas combustor 54.

  In the FC peripheral device 56, an exhaust gas combustor 52 is integrally provided in the heat exchanger 50, and an activation gas combustor 54 is provided adjacent to one end of the heat exchanger 50. The reformer 46 is provided adjacent to the other end of the heat exchanger 50.

  As shown in FIGS. 2 to 4, the heat exchanger 50 is arranged in a standing posture, and circulates the oxidant gas from vertically downward to vertically upward, as will be described later. The reformer 46 is disposed in a standing posture and distributes the reformed gas from the vertically downward direction to the vertically upward direction. A starting gas combustor 54 is directly attached to one side (one end) of the heat exchanger 50, and a reformer 46 is provided to the other side (other end) of the heat exchanger 50. Mounted directly. The reformer 46, the heat exchanger 50 (including the exhaust gas combustor 52), and the starting gas combustor 54 are stacked in the horizontal direction (arrow A direction).

  As shown in FIG. 2, an evaporator 48 and a desulfurizer 58 for removing sulfur compounds contained in city gas (raw fuel) are disposed below the heat exchanger 50 and the reformer 46. Is done.

The reformer 46 converts higher hydrocarbons (C ₂₊ ) such as ethane (C ₂ H ₆ ), propane (C ₃ H ₈ ) and butane (C ₄ H ₁₀ ) contained in city gas (raw fuel), This is a pre-reformer for steam reforming to a fuel gas mainly containing methane (CH ₄ ), hydrogen, and CO, and is set at an operating temperature of several hundred degrees Celsius.

  The operating temperature of the fuel cell 22 is as high as several hundred degrees Celsius. In the anode electrode 30, methane in the fuel gas is reformed to obtain hydrogen and CO. The hydrogen and CO are the anode electrode 30 of the electrolyte 26. Supplied to the side.

  As shown in FIG. 1, a raw fuel passage 60 a constituting the raw fuel supply device 14 is connected to the inlet of the desulfurizer 58, and a raw fuel supply path 60 b is connected to the outlet of the desulfurizer 58. The The raw fuel supply path 60 b is connected to the reformed gas supply chamber 62 a of the reformer 46.

  As shown in FIGS. 3 and 5, the reformed gas supply chamber 62 a communicates with the lower ends of the plurality of reforming pipelines 64, and the reformed gas discharge chamber 62 b is located at the upper end of the reforming pipelines 64. Communicate. One end of the fuel gas passage 66 communicates with the reformed gas discharge chamber 62b, and the other end of the fuel gas passage 66 communicates with the fuel gas inlet communication hole 44a of the fuel cell stack 24 (see FIG. 1). Each reforming line 64 is filled with a pellet-shaped catalyst (not shown) for reforming.

  A heating space 68 is formed between the reforming pipes 64. One end of the exhaust gas pipe 70a is opened in the heating space 68, while the other end of the exhaust gas pipe 70a is connected to the inlet of the heating path 72 of the evaporator 48, as shown in FIG. An exhaust pipe 70 b is connected to the outlet of the heating path 72 of the evaporator 48.

  A water passage 74 a constituting the water supply device 18 is connected to the inlet of the evaporator 48, and the water flowing through the water passage 74 a is heated by the exhaust gas flowing along the heating path 72 to generate water vapor. One end of the water vapor passage 74b is connected to the outlet of the evaporator 48, and the other end of the water vapor passage 74b joins the downstream position of the desulfurizer 58 with respect to the raw fuel supply passage 60b.

  As shown in FIGS. 4 and 6, the heat exchanger 50 is provided with an oxidant gas supply chamber (fluid supply chamber) 76a on the lower side (upstream side) and exhausts oxidant gas on the upper side (downstream side). A chamber (fluid discharge chamber) 76b is provided. Both ends of a plurality of oxidant gas pipes (fluid passages) 78 communicate with the oxidant gas supply chamber 76a and the oxidant gas discharge chamber 76b. A plurality of oxidant gas pipes 78 constitute a heat exchange unit 79.

  One end of the first oxidant gas supply path 80a is disposed in the oxidant gas supply chamber 76a. One end of the oxidant gas passage 82 is disposed in the oxidant gas discharge chamber 76b, and the other end of the oxidant gas passage 82 is connected to the oxidant gas inlet communication hole 42a of the fuel cell stack 24. (See FIG. 1).

  Inside the heat exchanger 50, a combustion chamber (combustion part) 84 that constitutes the exhaust gas combustor 52 is formed as well as a space in which a plurality of oxidant gas pipes 78 are accommodated. The combustion chamber 84 functions as a heat source that raises the temperature of the oxidant gas by a combustion reaction between the fuel gas (specifically, the fuel exhaust gas) and the oxidant gas (specifically, the oxidant exhaust gas).

  One end of an oxidant exhaust gas supply pipe (oxidant gas supply pipe) 86 and one end of a fuel exhaust gas supply pipe (fuel gas supply pipe) 88 are disposed in the combustion chamber 84 from the oxidant gas discharge chamber 76b side. As shown in FIG. 6, the pipe length L1 at which the fuel exhaust gas outlet 88a side of the fuel exhaust gas supply pipe 88 projects into the combustion chamber 84 is such that the oxidant exhaust gas outlet 86a side of the oxidant exhaust gas supply pipe 86 is inside the combustion chamber 84. It is configured to be longer than the pipe line length L2 projecting to the end.

  The oxidant exhaust gas outlet 86a is disposed in the vicinity of the oxidant gas discharge chamber 76b, while the fuel exhaust gas outlet 88a is disposed in the vicinity of the oxidant gas supply chamber 76a. The fuel exhaust gas outlet 88 a and the oxidant exhaust gas outlet 86 a are disposed at substantially diagonal positions in the combustion chamber 84.

  The fuel exhaust gas supply pipe 88 and the oxidant exhaust gas supply pipe 86 are arranged in parallel to each other. The fuel exhaust gas supply pipe 88 and the oxidant exhaust gas supply pipe 86 are disposed on both sides of the center position O across the center position O of the combustion chamber 84. In the combustion chamber 84, a combustion position FP where a combustion reaction is generated by the supplied fuel exhaust gas and oxidant exhaust gas is set on the lower side of the combustion chamber 84.

  In the combustion chamber 84, for example, a combustion catalyst 89 is provided at the fuel exhaust gas outlet 88a of the fuel exhaust gas supply pipe 88. The combustion catalyst 89 is applied to the inner wall of the combustion chamber 84, installed in the combustion chamber 84, or provided on the outer peripheral surface of the fuel exhaust gas supply pipe 88 or the outer peripheral surface of the oxidant exhaust gas supply pipe 86. be able to.

  As shown in FIG. 1, the other end of the oxidant exhaust gas supply pipe 86 is connected to the oxidant gas outlet communication hole 42b of the fuel cell stack 24, and the other end of the fuel exhaust gas supply pipe 88 is connected to the fuel cell stack. 24 fuel gas outlet communication holes 44b.

  As shown in FIG. 4, a wall plate (wall portion) 90 is disposed between the reformer 46 and the heat exchanger 50. A wall plate 90 is sandwiched between the flange portion 92 of the reformer 46 and the flange portion 94 of the heat exchanger 50, and these are integrally fixed by a plurality of bolts 96 and nuts 97. An opening 98 for supplying the combustion gas generated in the combustion chamber 84 of the heat exchanger 50 to the heating space 68 of the reformer 46 is formed on the upper side of the wall plate 90.

  As shown in FIG. 7, the startup gas combustor 54 has a combustion chamber 102 formed through an inner casing 100, and cooling for cooling the combustion chamber 102 outside the inner casing 100. A passage 104 is formed. A first oxidant gas passage 106 a constituting the oxidant gas supply device 16 is connected to the upper portion of the cooling passage 104, while a second oxidant gas passage 106 b is connected to the lower portion of the cooling passage 104. (See FIG. 1).

  In the combustion chamber 102, a rectangular flame region S is set corresponding to the combustion chamber 84 constituting the exhaust gas combustor 52 (see FIG. 4). A premixed fuel passage 108 is connected to the combustion chamber 102, and a second oxidant gas supply passage 80b and a raw fuel branch passage 110 are connected to the premixed fuel passage 108 as shown in FIG. Connected. As shown in FIG. 4, the starting gas combustor 54 and the heat exchanger 50 are integrally fixed with flange portions 92 and 94 provided by a plurality of bolts 96 and nuts 97, respectively.

  As shown in FIG. 1, the oxidant gas supply device 16 supplies the oxidant gas from the second oxidant gas passage 106b to the heat exchanger 50 and the starter gas combustor 54, that is, the first oxidant gas supply path. A regulating valve 112 for oxidant gas to be distributed is provided in 80a and the second oxidant gas supply path 80b.

  The raw fuel supply device 14 includes a raw fuel regulating valve 114 that distributes the raw fuel to the reformer 46 and the starting gas combustor 54, that is, to the raw fuel supply path 60 b and the raw fuel branch path 110. .

  The operation of the fuel cell system 10 configured as described above will be described below.

  When the fuel cell system 10 is activated, air (oxidant gas) and raw fuel are supplied to the activation gas combustor 54. Specifically, in the oxidant gas supply device 16, air is supplied to the first oxidant gas passage 106a under the driving action of the air pump. This air is introduced into the second oxidant gas passage 106 b through the cooling passage 104 of the starter gas combustor 54, and then the second oxidant gas under the action of adjusting the opening of the oxidant gas adjustment valve 112. The premixed fuel passage 108 is supplied from the supply passage 80b.

On the other hand, in the raw fuel supply device 14, for example, city gas (including CH ₄ , C ₂ H ₆ , C ₃ H ₈ , C ₄ H ₁₀ ) or the like is provided upstream of the raw fuel passage 60 a under the operation of the fuel gas pump. The raw fuel is supplied. The raw fuel is introduced into the raw fuel branch passage 110 under the action of opening adjustment of the raw fuel adjustment valve 114. The raw fuel is supplied to the premixed fuel passage 108 and mixed with air, and is supplied to the combustion chamber 102 in the starter gas combustor 54.

  For this reason, a mixed gas of raw fuel and air is supplied into the combustion chamber 102, and combustion is started when this mixed gas is ignited. Therefore, in the heat exchanger 50 directly connected to the starter gas combustor 54, as shown in FIG. 4, the combustion chamber 84 constituting the exhaust gas combustor 52 from the flame region S of the starter gas combustor 54. Is supplied with combustion gas.

  The combustion gas supplied to the combustion chamber 84 heats the heat exchanger 50 and moves to the heating space 68 of the reformer 46 through the opening 98 formed in the wall plate 90. Thereby, the reformer 46 is heated. An exhaust gas pipe 70 a is disposed in the heating space 68, and the exhaust gas pipe 70 a communicates with the heating path 72 of the evaporator 48. For this reason, after raising the temperature of the evaporator 48, the combustion gas is discharged from the exhaust pipe 70b.

  Next, when the evaporator 48 and the reformer 46 are heated to the set temperature, the opening degree of the oxidant gas adjustment valve 112 is adjusted, and the amount of air supplied to the second oxidant gas supply path 80b is reduced. At the same time, the opening degree of the raw fuel adjustment valve 114 is adjusted to reduce the amount of raw fuel supplied to the raw fuel branch passage 110. As a result, the amount of heat generated by reducing the amount of combustion by the starting gas combustor 54 is reduced. In the water supply device 18, the amount of water supplied to the evaporator 48 is adjusted.

  Therefore, in the oxidant gas supply device 16, the flow rate of air supplied to the first oxidant gas supply path 80a via the oxidant gas adjustment valve 112 increases, and the oxidant gas supply chamber 76a of the heat exchanger 50 increases. Air is introduced into the.

  As shown in FIG. 6, the air introduced into the oxidant gas supply chamber 76 a moves into the plurality of oxidant gas pipes 78 from the lower end side to the upper end side, and the combustion gas introduced into the combustion chamber 84. Is heated (heat exchange). The heated air is once supplied to the oxidant gas discharge chamber 76b and then supplied to the oxidant gas inlet communication hole 42a of the fuel cell stack 24 through the oxidant gas passage 82 (see FIG. 1).

  In the fuel cell stack 24, the heated air flows through the oxidant gas flow path 38 and is then discharged from the oxidant gas outlet communication hole 42 b to the oxidant exhaust gas supply pipe 86. As shown in FIG. 6, the oxidant exhaust gas supply pipe 86 has an oxidant exhaust gas outlet 86 a opened in a combustion chamber 84 constituting the exhaust gas combustor 52, and air is introduced into the combustion chamber 84.

  Further, in the raw fuel supply device 14, as shown in FIG. 1, the flow rate of the raw fuel supplied from the raw fuel passage 60 a to the desulfurizer 58 via the raw fuel adjustment valve 114 is increased. The raw fuel desulfurized by the desulfurizer 58 is supplied to the reformed gas supply chamber 62a of the reformer 46 through the raw fuel supply path 60b. On the other hand, the water supplied from the water supply device 18 is evaporated by the evaporator 48 and then flows through the raw fuel supply path 60b and is supplied to the reformed gas supply chamber 62a.

As shown in FIG. 5, the mixed gas of raw fuel and water vapor supplied to the reformed gas supply chamber 62a moves in the plurality of reformed pipes 64 from the lower end side to the upper end side. In the meantime, the mixed gas is heated by the combustion gas introduced into the heating space 68 and is steam-reformed through a pellet-shaped catalyst to remove (reform) C ₂₊ hydrocarbons to mainly produce methane. A reformed gas as a component is obtained. This reformed gas is once supplied to the reformed gas discharge chamber 62b as heated fuel gas, and then supplied to the fuel gas inlet communication hole 44a of the fuel cell stack 24 through the fuel gas passage 66 (FIG. 1).

  In the fuel cell stack 24, the heated fuel gas flows through the fuel gas passage 40 and is then discharged from the fuel gas outlet communication hole 44 b to the fuel exhaust gas supply pipe 88. As shown in FIG. 6, the fuel exhaust gas supply pipe 88 has a fuel exhaust gas outlet 88 a opened in a combustion chamber 84 constituting the exhaust gas combustor 52, and the fuel gas is introduced into the combustion chamber 84.

  As described above, the temperature of the fuel cell stack 24 is increased by circulating the heated air and the heated fuel gas. On the other hand, the combustion chamber 84 constituting the exhaust gas combustor 52 is supplied with air through an oxidant exhaust gas supply pipe 86 and fuel gas through a fuel exhaust gas supply pipe 88 as shown in FIG. Has been. Therefore, when the inside of the exhaust gas combustor 52 exceeds the self-ignition temperature of the fuel gas under the temperature rising action by the starter gas combustor 54, combustion by the air and the fuel gas is started in the combustion chamber 84.

  When combustion in the exhaust gas combustor 52 is started, the opening degree of the oxidant gas regulating valve 112 and the opening degree of the raw fuel regulating valve 114 are adjusted, and supply of air and raw fuel to the starting gas combustor 54 is performed. Is stopped.

  Next, when the fuel cell stack 24 reaches a state where power generation is possible, the fuel cell stack 24 starts generating power. During power generation of the fuel cell stack 24, air flows through the oxidant gas flow path 38 while fuel gas flows through the fuel gas flow path 40 in the same manner as at the time of startup. Accordingly, air is supplied to the cathode electrode 28 of each fuel cell 22 and fuel gas is supplied to the anode electrode 30 to generate power by a chemical reaction.

  Air used for the reaction (including unreacted air) is discharged to the oxidant exhaust gas supply pipe 86 as oxidant exhaust gas. Further, the fuel gas (including unreacted fuel gas) used for the reaction is discharged to the fuel exhaust gas supply pipe 88 as fuel exhaust gas. The oxidant exhaust gas and the fuel exhaust gas are sent to the exhaust gas combustor 52 and burned.

  In this case, in the first embodiment, as shown in FIG. 6, the heat exchanger 50 includes a space in which a plurality of oxidant gas pipes 78 are accommodated, and an exhaust gas combustor 52 is configured. A combustion chamber 84 is formed. For this reason, in the heat exchanger 50, the heat exchange part 79 and the combustion chamber (combustion part) 84 are provided integrally. Therefore, the temperature of the oxidant exhaust gas (fluid) flowing through each oxidant gas pipe 78 is efficiently increased, and the heat exchange efficiency is effectively improved.

  In particular, even in the fuel cell 22 having a large A / F (air / fuel gas), the supplied oxidant gas (air) can be effectively heated. As a result, the heat self-sustaining operation is reliably performed while suppressing the loss of heat energy.

  Further, no piping is required for the heat exchange unit 79 and the combustion chamber 84. For this reason, the combustion circuit (pipe etc.) is simplified and the number of parts is reduced, so that the size and cost can be reduced.

  In addition, an oxidant gas supply chamber 76 a is provided on the upstream side of the heat exchange unit 79, and an oxidant gas discharge chamber 76 b is provided on the downstream side of the heat exchange unit 79. Accordingly, the oxidant gas can be evenly distributed along each oxidant gas pipe line 78, and the oxidant gas can be heated uniformly.

  In addition, the fuel exhaust gas outlet 88a side protrudes into the combustion chamber 84 from the oxidant exhaust gas outlet 86a side. Thereby, since oxidant gas distribute | circulates in the opposite direction (opposite flow) with fuel gas, the heat exchange efficiency with the said oxidant gas distribute | circulated along each oxidant gas pipe line 78 further improves. Since the oxidant gas is heated satisfactorily, the temperature increase rate of the fuel cell stack 24 is increased, and the efficiency of the temperature increase process of the fuel cell stack 24 is improved.

  The fuel exhaust gas supply pipe 88 and the oxidant exhaust gas supply pipe 86 are arranged in parallel to each other. For this reason, the combustion position FP can be spread over the entire area in the combustion chamber 84, the temperature distribution in the combustion chamber 84 becomes smaller, and the oxidant gas flowing through each oxidant gas pipe line 78 rises evenly. Be warmed.

  Further, the fuel exhaust gas supply pipe 88 and the oxidant exhaust gas supply pipe 86 are disposed on both sides of the center position O across the center position O of the combustion chamber 84. Accordingly, since the combustion range is more reliably spread over the entire combustion portion, the temperature distribution in the combustion chamber 84 becomes as small as possible, and the oxidant gas flowing through each oxidant gas pipe 78 is heated evenly. It becomes possible to make it.

  Furthermore, a combustion catalyst 89 is provided in the combustion chamber 84. As a result, ignitability can be ensured even when the amount of fuel exhaust gas supplied to the combustion chamber 84 is small, and the oxidant gas flowing through each oxidant gas pipe 78 can be stably heated. Is possible.

  In addition, the heat exchanger 50 generates a combustion gas by a combustion reaction between a fuel exhaust gas (fuel gas) and an oxidant exhaust gas (oxidant gas) and supplies the combustion gas to the combustion chamber 84. A gas combustor 54 is provided adjacently (see FIGS. 2 to 4). For this reason, the heat exchanger 50, the exhaust gas combustor 52, and the starter gas combustor 54 are substantially integrated, and heat dissipation of the FC peripheral device (heat treatment system) 56 can be minimized.

  Therefore, it becomes possible to suppress the loss of heat energy, and the heat independent operation is promoted. Here, the heat self-sustained means that the operating temperature of the fuel cell is maintained only by the heat generated by itself without applying heat from the outside. In addition, since the combustion circuit (piping and the like) is simplified and the number of parts is reduced, the size and cost can be reduced.

  Further, the heat exchanger 50 is provided with a reformer 46 adjacent to reforming raw fuel mainly composed of hydrocarbons to generate fuel gas. Thereby, the reformer 46, the heat exchanger 50, and the exhaust gas combustor 52 are substantially integrated, and the heat radiation of the FC peripheral device (heat treatment system) 56 can be minimized. For this reason, it becomes possible to suppress the loss of thermal energy, and the thermal self-sustaining operation is promoted. In addition, since the combustion circuit (piping and the like) is simplified and the number of parts is reduced, the size and cost can be reduced.

  Furthermore, the heat exchanger 50 is incorporated in the solid oxide fuel cell stack 24, and the fuel exhaust gas discharged from the fuel cell stack 24 as fuel gas, the fuel cell stack 24 as oxidant gas, and the temperature rise An oxidant exhaust gas discharged from the oxidant gas is used as the fluid to be discharged.

  Therefore, it is most suitable for the high temperature fuel cell 22 such as SOFC (solid oxide fuel cell). In particular, the thermal self-sustaining operation of the SOFC can be promoted.

  FIG. 8 is a partial cross-sectional front view of the heat exchanger 120 constituting the heat treatment system according to the second embodiment of the present invention.

  In addition, the same reference number is attached | subjected to the component same as the heat exchanger 50 which concerns on 1st Embodiment, and the detailed description is abbreviate | omitted. Similarly, in the third embodiment described below, detailed description thereof is omitted.

  The heat exchanger 120 is provided with an oxidant gas discharge chamber 76b on the lower side and an oxidant gas supply chamber 76a on the upper side. The oxidant gas flows from the vertically upward direction to the vertically downward direction. One end of the first oxidant gas supply passage 122 is disposed in the oxidant gas supply chamber 76a, and one end of the oxidant gas passage 124 is disposed in the oxidant gas discharge chamber 76b.

  In the second embodiment configured as described above, the oxidant exhaust gas flowing through the oxidant exhaust gas supply pipe 86, the fuel exhaust gas flowing through the fuel exhaust gas supply pipe 88, and the oxidant gas flowing through each oxidant gas pipe line 78. Are set in the same direction (parallel flow). Thereby, in the second embodiment, the self-ignition temperature of the fuel gas can be maintained, and misfire in the combustion chamber 84 can be avoided.

  FIG. 9 is a partial cross-sectional front view of the heat exchanger 130 constituting the heat treatment system according to the third embodiment of the present invention.

  The heat exchanger 130 includes a fuel exhaust gas supply pipe (fuel gas supply pipe) 132, and the fuel exhaust gas supply pipe 132 is inserted into the combustion chamber 84 from the oxidant gas discharge chamber 76 b side to be supplied to the oxidant gas supply chamber. It extends to the vicinity of 76a. The fuel exhaust gas supply pipe 132 is provided with a slit 134 for supplying fuel gas to the combustion chamber 84 as a fuel gas outlet.

  The fuel exhaust gas supply pipe 132 has a front end (bottom) 132a closed, and a plurality of slits whose opening area is set small along the direction away from the front end 132a in the outer peripheral portion of the fuel exhaust gas supply pipe 132. 134a, 134b, 134c and 134d are formed. In addition, the slit 134 should just have at least 1 or more slit.

  In the third embodiment configured as described above, the fuel exhaust gas supply pipe 132 is provided with a slit 134 for supplying fuel gas to the combustion chamber 84 as a fuel gas outlet. For this reason, it can suppress that fuel gas burns in the combustion chamber 84 at a stretch, and the effect that durability is improved is obtained, without exceeding the heat-resistant temperature of a component.

  Furthermore, the fuel exhaust gas supply pipe 132 is closed at the tip 132a, and a plurality of slits 134a whose opening area is set small along the direction away from the tip 132a at the outer periphery of the fuel exhaust gas supply pipe 132. , 134b, 134c and 134d are formed.

  Therefore, the fuel gas in the combustion chamber 84 is not supplied all at once, and the flow rate of the fuel gas supplied into the combustion chamber 84 is evenly distributed along the axial direction of the fuel exhaust gas supply pipe 132. The As a result, the combustion range is more reliably spread over the entire combustion chamber 84, so that the temperature distribution in the combustion chamber 84 becomes as small as possible, and the oxidant exhaust gas flowing through each oxidant gas pipe 78 is evenly distributed. It becomes possible to raise the temperature.

DESCRIPTION OF SYMBOLS 10 ... Fuel cell system 12 ... Fuel cell module 14 ... Raw fuel supply device 16 ... Oxidant gas supply device 18 ... Water supply device 20 ... Control device 22 ... Fuel cell 24 ... Fuel cell stack 26 ... Electrolyte 28 ... Cathode electrode 30 ... Anode electrode 38 ... Oxidant gas channel 40 ... Fuel gas channel 46 ... Reformer 48 ... Evaporator 50, 120, 130 ... Heat exchanger 52 ... Exhaust gas combustor 54 ... Startup gas combustor 56 ... FC peripheral device 58 ... Desulfurizer 60a ... Raw fuel passage 60b ... Raw fuel supply passage 62a ... Reformed gas supply chamber 62b ... Reformed gas discharge chamber 64 ... Reformed pipe 66 ... Fuel gas passage 68 ... Heating space 70a ... Exhaust gas pipe 70b ... Exhaust pipe 72 ... Heating passage 74a ... Water passage 74b ... Water vapor passage 76a ... Oxidant gas supply chamber 76b ... Oxidant gas discharge chamber 78 ... Oxidant gas conduits 80a, 80b 122 ... Oxidant gas supply passage 82, 106a, 106b, 124 ... Oxidant gas passage 84 ... Combustion chamber 86 ... Oxidant exhaust gas supply pipe 86a ... Oxidant exhaust gas outlet 88, 132 ... Fuel exhaust gas supply pipe 88a ... Fuel exhaust gas outlet 89 ... Combustion catalyst 90 ... Wall plate 98 ... Opening portion 102 ... Combustion chamber 104 ... Cooling passage 108 ... Mixed fuel passage 110 ... Raw fuel branch passage 112 ... Oxidant gas adjustment valve 114 ... Raw fuel adjustment valves 134, 134a to 134d …slit

Claims (9)

A heat treatment system comprising a heat exchanger for raising the temperature of a fluid,
The heat exchanger includes a heat exchange section having a plurality of fluid passages for circulating the fluid;
A combustion section that is provided in the heat exchange section and serves as a heat source for raising the temperature of the fluid flowing through each fluid passage by a combustion reaction between the fuel gas and the oxidant gas;
A fluid supply chamber provided on the upstream side of the heat exchanging section, for supplying the fluid evenly to the fluid passages;
A fluid discharge chamber provided on the downstream side of the heat exchanging portion, for discharging the fluid from each fluid passage equally;
A fuel gas supply pipe communicating with the combustion section and having a fuel gas outlet for supplying the fuel gas to the combustion section;
An oxidant gas supply pipe communicating with the combustion part and having an oxidant gas outlet for supplying the oxidant gas to the combustion part;
With
The length of the pipe line in which the fuel gas outlet side of the fuel gas supply pipe projects into the combustion part is longer than the pipe length in which the oxidant gas outlet side of the oxidant gas supply pipe projects into the combustion part. A heat treatment system characterized by comprising.   2. The heat treatment system according to claim 1, wherein the fuel gas supply pipe and the oxidant gas supply pipe are arranged in parallel to each other.   3. The heat treatment system according to claim 1, wherein the fuel gas supply pipe and the oxidant gas supply pipe are disposed on both sides of the center position across the center position of the combustion section. Heat treatment system.   The heat processing system of any one of Claims 1-3 WHEREIN: A combustion catalyst is provided in the said combustion part, The heat processing system characterized by the above-mentioned.   5. The heat treatment system according to claim 1, wherein a slit for supplying the fuel gas to the combustion unit is provided as the fuel gas outlet in the fuel gas supply pipe. Heat treatment system. The heat treatment system according to claim 5, wherein a tip of the fuel gas supply pipe is closed.
A heat treatment system, wherein a plurality of slits whose opening areas are set small along a direction away from the tip are formed in an outer peripheral portion of the fuel gas supply pipe.   7. The heat treatment system according to claim 1, wherein the heat exchanger generates a combustion gas by a combustion reaction between the fuel gas and the oxidant gas, and the combustion gas is burned. A heat treatment system characterized in that a gas combustor for supplying to the section is provided adjacently.   The heat treatment system according to any one of claims 1 to 7, wherein the heat exchanger is adjacent to a reformer that reforms a raw fuel mainly composed of hydrocarbons and generates the fuel gas. A heat treatment system characterized by being provided. The heat treatment system according to any one of claims 1 to 8, wherein the heat treatment system is combined with a solid oxide fuel cell,
A heat treatment system using fuel exhaust gas discharged from the fuel cell as the fuel gas, oxidant exhaust gas discharged from the fuel cell as the oxidant gas, and oxidant gas as the fluid.

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