JP2008047444A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell system that suppresses performance deterioration of a humidifier. <P>SOLUTION: The fuel cell system is provided with a fuel cell 10 which generates power by an electrochemical reaction with a reaction gas, and the humidifier 20 for humidifying the reaction gas supplied to the fuel cell 10. The system is also provided with a refrigerant circulation device 71 for suppressing a temperature rise of the humidifier 20. By this, it is possible to suppress the humidifier 20 from being exposed under a high-temperature condition. A refrigerant in common with the refrigerant cooling the fuel cell 10 can be used for the refrigerant circulation device 71. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel cell system including a fuel cell that generates electric power by electrochemical reaction of a reaction gas.

In recent years, a fuel cell system that uses a fuel cell that generates electric power by an electrochemical reaction between a fuel gas and an oxidizing gas (hereinafter referred to as a reactive gas) has attracted attention. Some of such fuel cell systems include a humidifier that humidifies the reaction gas to the fuel cell, and further, a bypass that can bypass the humidifier to control the humidity of the reaction gas. Some have a passage (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 2003-31245

  In the fuel cell system including the humidifier that humidifies the reaction gas to the fuel cell as described above, the performance may be deteriorated when the humidifier is exposed to a high temperature condition. For example, in a humidifier that exchanges water vapor by circulating a reaction gas as a humidified gas on one of the inside and outside of the hollow fiber and a reaction off gas as a humidified gas on the other, the hollow fiber deteriorates at high temperatures. .

  Then, an object of this invention is to provide the fuel cell system which can suppress the performance degradation of a humidifier.

  In order to achieve the above object, the present invention provides a fuel cell system comprising a fuel cell for generating electricity by electrochemical reaction of a reaction gas, and a humidifier for humidifying the reaction gas to the fuel cell, wherein the humidification Temperature rise suppression means for suppressing the temperature rise of the vessel.

  By setting it as this structure, since a temperature rise suppression means will suppress the temperature rise of a humidifier, it can suppress that a humidifier is exposed to high temperature conditions.

  In this case, the temperature rise suppression means may be a refrigerant circulation device that suppresses the temperature rise of the humidifier by circulating refrigerant.

  Further, the temperature rise suppression means may be a radiating fin provided outside the humidifier to exchange heat with the outside air.

  In addition, when a cooling system that controls the temperature of the fuel cell with a refrigerant is provided, the refrigerant circulation device may use a common refrigerant with the fuel cell.

  Furthermore, the temperature rise suppression means may control the temperature rise of the humidifier according to the temperature of the humidifier.

  In this case, the temperature rise suppression means may suppress the temperature rise of the humidifier by bypassing the gas toward the humidifier to the humidifier.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to suppress that a humidifier is exposed to high temperature conditions, and can suppress the performance deterioration of a humidifier.

  Next, a first embodiment of a fuel cell system according to the present invention will be described with reference to FIGS.

  FIG. 1 is a system configuration diagram of the fuel cell system 1. The fuel cell system 1 is used as an in-vehicle power generation system for fuel cell vehicles, a power generation system for any moving body such as a ship, an aircraft, a train, or a walking robot, and also as a power generation facility for buildings (housing, buildings, etc.). Although it can be applied to stationary power generation systems, it is specifically for automobiles.

  The fuel cell system 1 includes a fuel cell 10 that generates power by receiving supply of reaction gas (oxidation gas and fuel gas), and a cathode system that adjusts gas supply of the oxidation gas (air) to the fuel cell 10. The oxidizing gas piping system 2, the anode fuel gas piping system 3 that adjusts the gas supply of the fuel gas (hydrogen gas), and the cooling system that circulates the cooling water as the refrigerant in order to control the temperature of the fuel cell 10. 4 is provided.

  The oxidizing gas piping system 2 includes an oxidizing gas supply pipe 21 that supplies the oxidizing gas (air) humidified by the humidifier 20 to the fuel cell 10, and a lead-out piping that guides the oxidizing off gas discharged from the fuel cell 10 to the humidifier 20. 22 and a discharge pipe 23 for guiding the oxidizing off gas from the humidifier 20 to the outside. The oxidizing gas supply pipe 21 is provided with a compressor 24 that takes in the oxidizing gas (air) in the atmosphere and pumps it to the humidifier 20.

  The fuel gas piping system 3 supplies fuel gas supplied from a fuel supply source (not shown) to the fuel cell 10 and returns or dilutes off-gas of the fuel gas discharged from the fuel cell 10 to the fuel cell 10 again. Exhaust to the outside air.

  The fuel gas supplied from the fuel gas piping system 3 to the fuel cell 10 and the oxidizing gas humidified by the humidifier 20 via the oxidizing gas supply piping 21 by pressure feeding by the compressor 24 and introduced into the fuel cell 10 are: The fuel cell 10 generates an electrochemical reaction to generate electricity.

  The cooling system 4 includes a cooling pipe 41 that is connected to the fuel cell 10 and circulates cooling water. The cooling pipe 41 is provided with a fuel cell cooling radiator 42 that radiates heat of the cooling water to the outside, and a pump 43 that pressurizes and circulates the cooling water. The fuel cell cooling radiator 42 includes A cooling fan 42a that is rotationally driven by a motor is provided.

  In the first embodiment, the branch pipe that branches from the downstream side of the pump 43 and the upstream side of the fuel cell 10 in the cooling pipe 41 and joins the downstream side of the fuel cell 10 and the upstream side of the radiator 42 for cooling the fuel cell. 51. The branch pipe 51 includes, in order from the upstream side, a valve 52 that opens and closes the branch pipe 51, a humidifier cooling radiator 53 that radiates heat of cooling water flowing through the branch pipe 51 to the outside, and A humidifier 20 is arranged. The humidifier cooling radiator 53 is provided with a cooling fan 53a that is rotationally driven by a motor.

  As shown in FIG. 2, the humidifier 20 includes a case 60 and a hollow fiber bundle 61 accommodated in the case 60. Here, the case 60 is formed mainly of aluminum, for example, and the outer shell as a whole has a double structure so as to form the refrigerant flow path 62 therebetween. One end of the case 60 is provided with a refrigerant introduction port 63 that is connected to the humidifier cooling radiator 53 side of the branch pipe 51 to guide the cooling water to the refrigerant flow path 62, and the other end of the case 60 is provided with the branch pipe 51. A refrigerant discharge port 64 for discharging the cooling water after being connected to the side opposite to the humidifier cooling radiator 53 and flowing through the refrigerant flow path 62 is provided.

  In addition, the case 60 is provided at one end of the same case 60 as the refrigerant introduction port 63, and an off-gas introduction port 65 through which high-humidity high-temperature oxidizing off-gas from the fuel cell 10 is introduced into the case 60. At the other end of the same case 60 as the refrigerant discharge port 64 and a cylindrical chamber 66 that absorbs moisture from the oxidizing off-gas introduced by the hollow fiber bundle 61 in the center of the cylindrical hollow fiber bundle 61. The hollow fiber bundle 61 has an off-gas discharge port 67 for exhausting the oxidized off-gas after moisture absorption to the outside air.

  Furthermore, the case 60 is supplied with the oxidizing gas pumped by the compressor 24, and the oxidizing gas inlet 68 that leads the introduced oxidizing gas to the hollow fiber bundle 61 for humidification is provided on the opposite side of the oxidizing gas inlet 68. It has an oxidizing gas outlet 69 that is provided and discharges the humidified oxidizing gas toward the fuel cell 10 by the hollow fiber bundle 61.

  In this humidifier 20, the oxidizing off gas introduced from the off gas introduction port 65 circulates through the hollow portions (inside) of the hollow fibers constituting the hollow fiber bundle 61 and is introduced from the oxidizing gas introduction port 68. The oxidizing gas humidified by the oxidizing off gas circulates on the outer peripheral side (outside) of each hollow fiber, but these oxidizing off gas and oxidizing off gas are not mixed with each other by a seal (contamination prevention) mechanism (not shown). .

  Then, for example, when the cooling fan 42a of the fuel cell cooling radiator 42 and the pump 43 are in a driving state for cooling the fuel cell 10, the valve 52 is set while the cooling fan 53a of the humidifier cooling radiator 53 is stopped. When opened, a part of the cooling water which flows through the cooling pipe 41 and exchanges heat with the outside air by the fuel cell cooling radiator 42 and is pumped to the fuel cell 10 by the pump 43 is branched and flows into the branch pipe 51. It will be.

  Then, the tributary of the cooling water passes through the humidifier 20 and passes through the refrigerant flow path 62 of the humidifier 20 to exchange heat with the humidifier 20 to suppress the temperature rise, and after cooling the fuel cell 10 Will join the main cooling water.

  Further, for example, when the cooling fan 42a of the fuel cell cooling radiator 42 and the pump 43 are in a driving state to cool the fuel cell 10, the cooling fan 53a of the humidifier cooling radiator 53 is driven to open the valve 52. Then, a part of the cooling water that flows through the cooling pipe 41 and exchanges heat with the outside air by the fuel cell cooling radiator 42 and is pumped to the fuel cell 10 by the pump 43 flows through the branch pipe 51 as a tributary for cooling the humidifier. The heat is exchanged with the outside air by the radiator 53 and then passes through the humidifier 20, and the heat is exchanged with the humidifier 20 through the refrigerant flow path 62 of the humidifier 20, thereby further suppressing the temperature rise.

  Therefore, the cooling pipe 41, the fuel cell cooling radiator 42, the pump 43, the branch pipe 51, the valve 52, the humidifier cooling radiator 53, and the control device 70 that controls them are circulated cooling water and fuel. A coolant circulation device (temperature increase suppression means) 71 that suppresses the temperature increase of the humidifier 20 by using the cooling water common to the battery 10 is configured.

  For example, based on a signal from a sensor that directly detects the temperature of the humidifier 20, the control device 70 opens / closes the valve 52 and drives the cooling fan 53 a of the humidifier cooling radiator 53, that is, increases the temperature of the humidifier 20. The suppression control is performed. The heat source for the temperature increase of the humidifier 20 is mainly the fuel cell 10, and the temperature of the humidifier 20 increases as the temperature of the fuel cell 10 increases. Alternatively, the temperature on the fuel cell 10 side can be detected as a substitute for the temperature of the humidifier 20, and control can be performed based on the temperature on the fuel cell 10 side.

  That is, if the temperature of the fuel cell 10 which is one heat source of the temperature rise of the humidifier 20 is high, the temperature of the oxidizing off gas discharged from the fuel cell 10 becomes higher accordingly, and the humidifying into which the oxidizing off gas is introduced. Since the temperature of the vessel 20 increases accordingly, the control can be performed by the temperature of the fuel cell 10.

  Here, the temperature of the fuel cell 10 is detected from the outlet temperature of the cooling water immediately after passing through the fuel cell 10 or the outlet temperature of the oxidizing off gas immediately after passing through the fuel cell 10, and the refrigerant is based on the temperature of this fuel cell 10. The valve 52 of the circulation device 71 is opened and closed and the cooling fan 53a of the humidifier cooling radiator 53 is driven, that is, the temperature rise control of the humidifier 20 is controlled.

  For example, the control device 70 drives the pump 43 except during a predetermined warm-up operation of the fuel cell 10, and circulates cooling water to the fuel cell 10. Then, the driving of the cooling fan 42 a of the fuel cell cooling radiator 42 is controlled according to the temperature of the fuel cell 10. If the detected temperature of the fuel cell 10 is higher than a predetermined value, for example, the cooling fan 42a is driven, and the cooling water in the cooling pipe 41 is heat-exchanged (cooled) with the outside air by the fuel cell cooling radiator 42. If it is lower, the cooling fan 42a is stopped.

  For example, when the detected temperature of the fuel cell 10 is lower than the first predetermined value, the control device 70 stops the cooling fan 53a of the humidifier cooling radiator 53 and closes the valve 52. . That is, the control for suppressing the temperature rise of the humidifier 20 by the refrigerant circulation device 71 is not performed. In this state, only the temperature control of the fuel cell 10 is performed.

  On the other hand, when the temperature of the fuel cell 10 is equal to or higher than the first predetermined value, the control device 70 performs the first suppression control of the temperature increase of the humidifier 20 by the refrigerant circulation device 71. That is, the cooling fan 53a of the humidifier cooling radiator 53 is stopped and the valve 52 is opened.

  Then, in order to cool the fuel cell 10, a part of the cooling water that flows through the cooling pipe 41 and appropriately exchanges heat with the outside air by the fuel cell cooling radiator 42 and is pumped to the fuel cell 10 by the pump 43 is branched and branched. And flows through the branch pipe 51, passes through the refrigerant flow path 62 in the case 60 of the humidifier 20, and performs heat exchange (cooling) with the humidifier 20.

  Furthermore, when the temperature of the fuel cell 10 is equal to or higher than a second predetermined value higher than the first predetermined value, the control device 70 performs the second suppression control of the temperature increase of the humidifier 20 by the refrigerant circulation device 71. Do. That is, the cooling fan 53a of the humidifier cooling radiator 53 is driven and the valve 52 is opened.

  Then, in order to cool the fuel cell 10, one of the cooling water that flows through the cooling pipe 41 and exchanges heat with the outside air by the fuel cell cooling radiator 42 in which the cooling fan 42 a is in the driven state and is pumped toward the fuel cell 10 by the pump 43. The portion branches and becomes a tributary flow into the branch pipe 51, and after further heat exchange (cooling) by the humidifier cooling radiator 53, passes through the refrigerant flow path 62 in the humidifier 20 and the humidifier 20. Perform heat exchange (cooling).

  In addition, as a case where the temperature of the fuel cell 10 becomes equal to or higher than the second predetermined value, for example, when the fuel cell 10 continues to be in a high load operation (operation when the power generation request is relatively high), or the fuel cell 10 This is a case where the resistance is increased and the heat generation amount is increased, and the fuel cell cooling radiator 42 cannot expect a sufficient temperature drop.

  Note that not only the temperature is compared with the reference value as described above, but also the temperature of the humidifier 20 from the temperature increase rate at the time when the temperature exceeds the reference value during the predetermined time in the future. In the case where it is estimated that the temperature will be equal to or higher than the predetermined value, the first suppression control described above is performed, and the temperature of the humidifier 20 is estimated to be equal to or higher than the second predetermined value in a predetermined time in the future. The above-described second suppression control may be performed.

  According to 1st Embodiment described above, since the refrigerant | coolant circulation apparatus 71 will suppress the temperature rise of the humidifier 20 as needed, it suppresses that the humidifier 20 is exposed to high-temperature conditions for a long time. be able to. Therefore, the performance deterioration of the hollow fiber bundle 61 that is particularly damaged by heat of the humidifier 20 can be suppressed, and the durability of the humidifying performance can be ensured.

  Moreover, since the temperature rise of the humidifier 20 is suppressed using the refrigerant | coolant circulation apparatus 71 which suppresses the temperature rise of the humidifier 20 with the circulating refrigerant | coolant, the temperature rise of the humidifier 20 can be suppressed stably. In addition, since the refrigerant circulation device 71 that suppresses the temperature rise of the humidifier 20 uses the cooling water common to the fuel cell 10, the system configuration such as the pump 43 can be shared, and the cost can be reduced.

  Furthermore, since the refrigerant circulation device 71 performs the suppression control of the temperature rise of the humidifier 20 according to the temperature of the fuel cell 10 that changes according to the temperature of the humidifier 20, the temperature rise of the humidifier 20 properly without waste. Can be suppressed.

  In the fuel cell system 1 according to the first embodiment, the temperature rise suppression control (first suppression control) of the humidifier 20 is performed only by the fuel cell cooling radiator 42 without providing the humidifier cooling radiator 53. May be.

  Moreover, in the fuel cell system 1 which concerns on 1st Embodiment, you may change the humidifier 20 as shown in FIGS.

  In the humidifier 20 of FIG. 3, the case 60 is placed around the offgas introduction port 65 so that heat exchange is intensively performed in the vicinity of the offgas introduction port 65 into which high-temperature oxidizing offgas having high humidity is introduced from the fuel cell 10. And only the vicinity thereof has a double structure, and a refrigerant flow path 80 connected to the refrigerant inlet 63 and the refrigerant outlet 64 is formed in this portion. If comprised in this way, cost reduction and size reduction of the case 60 can be achieved compared with the case where the whole case 60 is made into a double structure.

  In the humidifier 20 of FIG. 4, a refrigerant flow path 82 connected to the refrigerant introduction port 63 and the refrigerant discharge port 64 is formed between the case 60 and the hollow fiber bundle 61 by a plurality of branched pipes 81, and is hollow. Heat is exchanged with the hollow fiber bundle 61 at a closer position so that the cooling water flows around the yarn bundle 61. If comprised in this way, cost reduction and size reduction of the case 60 can be achieved compared with the case where the whole case 60 is made into a double structure.

  In the humidifier 20 of FIG. 5, a refrigerant flow path connected to the refrigerant inlet 63 and the refrigerant outlet 64 through the pipe 83 in the case 60 so as to penetrate the central axis of the hollow fiber bundle 61 having a hollow cylindrical shape. 84, and heat exchange with the hollow fiber bundle 61 is performed so that the cooling water flows through the hollow portion at the center of the hollow fiber bundle 61. If comprised in this way, cost reduction and size reduction of the case 60 can be achieved compared with the case where the whole case 60 is made into a double structure. Moreover, compared with the humidifier 20 of FIG. 4, the heat accumulation in the center of the hollow fiber bundle 61 can be suppressed, and the cooling performance can be improved.

  In the humidifier 20 of FIG. 6, a heat radiating fin (temperature rise suppression means) 85 capable of promoting heat exchange with the outside air is further provided outside the case 60 of the humidifier 20 of FIG. The performance of suppressing the temperature rise is improved by being applied to the heat radiating fins 85.

  In the humidifier 20 of FIG. 7, a radiating fin 86 for exchanging heat with outside air is provided only around and near the off-gas inlet 65 of the case 60 of the humidifier 20 of FIG. The temperature rise suppression performance is improved.

  In addition, you may combine the above structure suitably. For example, in the humidifier 20 of FIG. 8, the entire case 60 has a double structure to form the refrigerant flow path 62, and branch from the refrigerant flow path 62 so as to penetrate the central axis of the hollow fiber bundle 61. A refrigerant flow path 84 is formed through the pipe 83 so that cooling water flows through the entire case 60 and the center of the hollow fiber bundle 61 to exchange heat with the case 60 and the hollow fiber bundle 61.

  That is, the configuration of the humidifier 20 in FIG. 2 and the configuration of the humidifier 20 in FIG. 5 are combined. If comprised in this way, while being able to improve a heat exchange performance further, the hollow fiber bundle 61 can be cooled more uniformly. Therefore, deterioration due to heat can be uniformly suppressed in the entire hollow fiber bundle 61.

  Further, in the humidifier 20 of FIG. 9, the refrigerant flow path 82 is formed between the case 60 and the hollow fiber bundle 61 by the pipe 81 having the refrigerant introduction port 63A and the refrigerant discharge port 64A, and the hollow fiber bundle 61 is formed. A refrigerant flow path 84 is formed through a pipe 83 having a refrigerant introduction port 63B and a refrigerant discharge port 64B so as to pass through the central axis, and heat exchange is performed between the periphery and the center of the hollow fiber bundle 61.

  That is, the configuration of the humidifier 20 in FIG. 4 and the configuration of the humidifier 20 in FIG. 5 are combined. If comprised in this way, while being able to improve a heat exchange performance further, the hollow fiber bundle 61 can be cooled more uniformly. Therefore, deterioration due to heat can be uniformly suppressed in the entire hollow fiber bundle 61.

  In this case, as shown in FIG. 10, the branch pipe 51 is connected to the pipe 81 around the hollow fiber bundle 61, and the branch pipe 88 further branched from the position immediately before the humidifier 20 of the branch pipe 51 is connected to the hollow fiber bundle 61. Are connected to a pipe 83 on the central axis.

  Then, a separate valve 89 is provided downstream of the branch pipe 88 in the branch pipe 51. For example, when the temperature of the fuel cell 10 is lower than a predetermined value, the valve 89 is closed and the central axis of the hollow fiber bundle 61 is closed. When cooling water is allowed to flow only to the upper pipe 83 and the temperature of the fuel cell 10 is equal to or higher than a predetermined value, the valve 89 is opened to add to the pipe 83 on the central axis of the hollow fiber bundle 61, and around the hollow fiber bundle 61. The cooling capacity is adjusted by flowing cooling water through the pipe 81.

  Next, a second embodiment of the fuel cell system according to the present invention will be described with reference to FIG. 11, focusing on the differences from the first embodiment. In the second embodiment, the cooling line that suppresses the temperature increase of the humidifier 20 is provided independently of the cooling line that suppresses the temperature increase of the fuel cell 10.

  That is, the cooling pipe 41, the fuel cell cooling radiator 42, and the pump 43 are provided to circulate the cooling water in the closed circuit in the fuel cell 10, and separately from these, the refrigerant inlet 63 and the refrigerant outlet 64 of the humidifier 20 are provided. Are connected by an external refrigerant pipe 91, and the refrigerant pipe 91 is provided with a valve 52 and a humidifier cooling radiator 53 similar to those of the first embodiment, and a separate pump 92, and a closed circuit for the humidifier 20 is provided. The refrigerant circulation device (temperature rise suppression means) 93 is configured.

  Also in the second embodiment, the control device 70 changes according to the temperature of the humidifier 20 from, for example, the outlet temperature of the cooling water immediately after passing through the fuel cell 10 or the oxidizing off-gas temperature immediately after passing through the fuel cell 10. The temperature of the fuel cell 10 to be detected is detected, and based on the temperature of the fuel cell 10, the valve 52 of the refrigerant circulation device 71 is opened and closed, the cooling fan 53a of the humidifier cooling radiator 53 is driven, and the pump 92 is driven. 20 to suppress the temperature rise.

  For example, when the detected temperature of the fuel cell 10 is lower than the first predetermined value, the control device 70 stops the cooling fan 53a of the humidifier cooling radiator 53 and also closes the valve 52. That is, the control for suppressing the temperature rise of the humidifier 20 by the refrigerant circulation device 93 is not performed.

  On the other hand, when the temperature of the fuel cell 10 is equal to or higher than the first predetermined value, the control device 70 performs the first suppression control of the temperature increase of the humidifier 20 by the refrigerant circulation device 93. That is, the cooling fan 53a of the humidifier cooling radiator 53 is stopped, the valve 52 is opened, and the pump 92 is driven. Then, the cooling water in the refrigerant pipe 91 pumped by the pump 92 passes through the refrigerant flow path 62 in the case 60 of the humidifier 20 and performs heat exchange (cooling) with the humidifier 20.

  Furthermore, when the temperature of the fuel cell 10 is equal to or higher than a second predetermined value higher than the first predetermined value, the control device 70 performs the second suppression control of the temperature increase of the humidifier 20 by the refrigerant circulation device 71. Do. That is, the cooling fan 53a of the humidifier cooling radiator 53 is driven, the valve 52 is opened, and the pump 92 is driven.

  Then, after the cooling water in the refrigerant pipe 91 pumped by the pump 92 is heat-exchanged (cooled) by the humidifier cooling radiator 53, it passes through the refrigerant flow path 62 in the humidifier 20 and is heated with the humidifier 20. Replace (cool).

  According to such 2nd Embodiment, similarly to 1st Embodiment, the temperature rise of the humidifier 20 is controlled using the refrigerant | coolant circulation apparatus 93 which suppresses the temperature rise of the humidifier 20 with the circulating refrigerant | coolant. In order to suppress according to the temperature of the fuel cell 10 that changes according to the temperature of the fuel cell, it is possible to suppress the deterioration of the performance of the hollow fiber bundle 61 that is particularly damaged by heat of the humidifier 20 stably and appropriately without waste. In addition, since the refrigerant circulation device 93 that suppresses the temperature rise of the humidifier 20 is provided independently of the cooling line of the fuel cell 10, the temperature rise of the humidifier 20 can be more precisely suppressed. Control can be performed.

  Also in 2nd Embodiment, it is possible to use the humidifier 20 shown in FIGS. 2-9 similarly to 1st Embodiment.

  Note that, in both the first embodiment and the second embodiment, the temperature rise of the humidifier 20 may be suppressed by bypassing the high-temperature oxidizing off gas toward the humidifier 20 to the humidifier 20. That is, a bypass pipe that bypasses the humidifier 20 is provided, and when the temperature of the humidifier 20 is higher than a predetermined value, by switching the valve, a high-temperature oxidant off-gas flows through the bypass pipe and does not flow into the humidifier 20. When the temperature of the vessel 20 is lower than a predetermined value, it is possible to control such that the oxidizing off gas flows through the humidifier 20 by switching the valve and does not flow through the bypass pipe.

  In order to further reduce the cost, there is no configuration for flowing the cooling water to the humidifier 20, and as shown in FIG. 12, only the radiating fins 85 are provided on the body portion of the case 60, or as shown in FIG. Only the heat radiation fins 86 may be provided around and in the vicinity of the off gas inlet 65 of the case 60.

1 is a schematic configuration diagram of a first embodiment of a fuel cell system according to the present invention. Sectional drawing of the humidifier of the embodiment. Sectional drawing of the modification of the humidifier of the embodiment. Sectional drawing of the modification of the humidifier of the embodiment. Sectional drawing of the modification of the humidifier of the embodiment. Sectional drawing of the modification of the humidifier of the embodiment. Sectional drawing of the modification of the humidifier of the embodiment. Sectional drawing of the modification of the humidifier of the embodiment. Sectional drawing of the modification of the humidifier of the embodiment. The partial block diagram of the fuel cell system at the time of using the humidifier of FIG. The schematic block diagram of 2nd Embodiment of the fuel cell system which concerns on this invention. Sectional drawing of the modification of a humidifier. Sectional drawing of the modification of a humidifier.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Fuel cell system, 10 ... Fuel cell, 20 ... Humidifier, 71, 93 ... Refrigerant circulation apparatus (temperature rise suppression means), 85, 86 ... Radiation fin (temperature rise suppression means).

Claims (6)

A fuel cell system comprising a fuel cell for generating electricity by electrochemical reaction of a reaction gas, and a humidifier for humidifying the reaction gas to the fuel cell,
The fuel cell system which has a temperature rise suppression means which suppresses the temperature rise of the said humidifier.   2. The fuel cell system according to claim 1, wherein the temperature rise suppression unit is a refrigerant circulation device that suppresses a temperature rise of the humidifier by circulating refrigerant.   3. The fuel cell system according to claim 1, wherein the temperature rise suppression means is a radiating fin that is provided outside the humidifier and exchanges heat with outside air. 4. A cooling system for controlling the temperature of the fuel cell with a refrigerant;
The fuel cell system according to claim 2, wherein the refrigerant circulation device uses a common refrigerant with the fuel cell.   The fuel cell system according to any one of claims 1 to 4, wherein the temperature rise suppression means controls the temperature rise of the humidifier according to the temperature of the humidifier.   6. The fuel cell system according to claim 5, wherein the temperature rise suppression unit suppresses a temperature rise of the humidifier by bypassing a gas toward the humidifier with respect to the humidifier.

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