JP2008020163A - Humidifier device and fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a humidifier device and a fuel cell system capable of improving low temperature starting performance in the winter, a cold district, or the like. <P>SOLUTION: The fuel cell system is provided with fuel cells for generating power by electrochemical reaction of oxidation gas and fuel gas, and the humidifier device 19 for humidifying at least one of the oxidation gas or the fuel gas supplied to the fuel cell. The humidifier device 19 is provided with a humidification module 15 humidifying and exhausting the supplied gas, piping 11a, 11b connected to the humidification module 15, and adjusting means 17, 18 for adjusting a gas supply amount to the humidification module 15 provided on the piping 11a, 11b. The adjusting means 17, 18 are arranged at a height higher than the humidification module 15 in a gravitational direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a humidifier and a fuel cell system, and more particularly to a technique effective for improving low-temperature startability in winter or cold districts.

  In recent years, a fuel cell system that uses a fuel cell (cell) that generates electric power by an electrochemical reaction between a fuel gas and an oxidizing gas (hereinafter referred to as a reactive gas) attracts attention. The fuel cell system supplies high-pressure fuel gas from a fuel tank to the fuel cell and pressurizes and supplies air to cause an electrochemical reaction between the fuel gas and the oxidizing gas in the fuel cell to generate an electromotive force.

Some of the fuel cell systems include a humidification module (humidifier) that humidifies the oxidizing gas supplied to the fuel cell (for example, see Patent Document 1 below). As the humidification module, for example, there is a module that replenishes moisture from the outside in addition to a module that utilizes moisture contained in the oxidizing off gas discharged from the fuel cell.
JP 2005-322508 A

  When a fuel cell system equipped with such a humidifying module is used in winter or cold regions, water remaining in the humidifying module is connected to the humidifying module while the fuel cell system is stopped. When it flows into the valve, the water freezes and the valve stops moving, and there is a problem that smooth low-temperature start-up cannot be performed.

  Then, an object of this invention is to provide the humidification apparatus and fuel cell system which can improve the low temperature starting property in winter, a cold region, etc.

  In order to solve the above problems, a humidifier according to the present invention includes a humidifying module that humidifies and discharges a supplied gas, a pipe connected to the humidifying module, and the humidifying module provided in the pipe. A humidifying apparatus comprising: an adjusting unit that adjusts a gas supply amount to the humidifying module, wherein the adjusting unit is disposed higher in a gravitational direction than the humidifying module.

  The pipe includes an upstream pipe for supplying gas to the humidification module, and a downstream pipe for discharging the gas humidified by the humidification module from the humidification module. You may provide the communicating path which connects the said upstream piping and the said downstream piping in the upstream of a humidification module, and the valve which adjusts the open / close state of the said communicating path.

  The fuel cell system of the present invention includes a fuel cell that generates electric power by an electrochemical reaction between an oxidizing gas and a fuel gas, and a humidifier that humidifies at least one of the oxidizing gas and the fuel gas supplied to the fuel cell. In the fuel cell system provided, a humidifier having the above-described configuration is used as the humidifier.

  According to the above configuration, since the adjusting means (communication path and valve) is provided at a higher position than the humidification module, even when used in a low temperature environment such as a winter or a cold district, The remaining water does not flow into the adjusting means when the operation is stopped. Therefore, even if the outside air temperature falls below, for example, 0 ° C. (water freezing temperature), it is possible to suppress the occurrence of malfunction due to the consolidation of the adjusting means.

  According to the present invention, it is possible to improve low-temperature startability in winter or cold regions.

  Hereinafter, a fuel cell system according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram of a fuel cell system.

  The fuel cell system 1 includes a fuel cell 2, an oxidizing gas piping system 3 that supplies air (oxygen) as an oxidizing gas to the fuel cell 2, and a fuel gas piping system 4 that supplies hydrogen as a fuel gas to the fuel cell 2. And a refrigerant piping system 5 that supplies the refrigerant to the fuel cell 2 to cool the fuel cell 2, a power system 6 that charges and discharges the power of the system, and a control unit 7 that controls the entire system. .

  The fuel cell 2 is formed of, for example, a solid polymer electrolyte type and has a stack structure in which a large number of single cells are stacked. A single cell of the fuel cell 2 has an air electrode on one surface of an electrolyte made of an ion exchange membrane, a fuel electrode on the other surface, and a pair of separators so as to sandwich the air electrode and the fuel electrode from both sides. have. The fuel gas is supplied to the fuel gas flow path of one separator and the oxidizing gas is supplied to the oxidizing gas flow path of the other separator, and the fuel cell 2 generates electric power by this gas supply.

  The oxidizing gas piping system 3 has a supply path 11 through which the oxidizing gas supplied to the fuel cell 2 flows, and a discharge path 12 through which the oxidizing off gas discharged from the fuel cell 2 flows. The supply path 11 is provided with a compressor 14 that takes in the oxidizing gas via the filter 13 and a humidification module 15 that humidifies the oxidizing gas fed by the compressor 14. The oxidizing off-gas flowing through the discharge path 12 passes through the back pressure regulating valve 16 and is finally exhausted into the atmosphere outside the system as exhaust gas. The compressor 14 takes in the oxidizing gas in the atmosphere by driving the motor 14a.

  The fuel gas piping system 4 includes a hydrogen supply source 21, a supply path 22 through which hydrogen gas supplied from the hydrogen supply source 21 to the fuel cell 2 flows, and a supply path for supplying hydrogen offgas (fuel offgas) discharged from the fuel cell 2. 22, a circulation path 23 for returning to the junction point A of 22, a pump 24 that pumps the hydrogen off-gas in the circulation path 23 to the supply path 22, and a discharge path 25 that is branched and connected to the circulation path 23. .

  The hydrogen supply source 21 is composed of, for example, a high-pressure tank or a hydrogen storage alloy, and is configured to be able to store, for example, 35 MPa or 70 MPa of hydrogen gas. When the main valve 26 of the hydrogen supply source 21 is opened, hydrogen gas flows out into the supply path 22. The hydrogen gas is finally depressurized to about 200 kPa, for example, by the pressure regulating valve 27 and other pressure reducing valves, and supplied to the fuel cell 2.

  A shutoff valve 28 is provided on the upstream side of the junction point A of the supply path 22. The hydrogen gas circulation system is configured by sequentially communicating a flow path downstream from the confluence point A of the supply path 22, a fuel gas flow path formed in the separator of the fuel cell 2, and the circulation path 23. Yes. The hydrogen pump 24 circulates and supplies hydrogen gas in the circulation system to the fuel cell 2 by driving the motor 24a.

  The discharge path 25 is provided with a purge valve 33 that is a shut-off valve. By appropriately opening the purge valve 33 when the fuel cell system 1 is operating, impurities in the hydrogen off gas are discharged together with the hydrogen off gas to a hydrogen diluter (not shown). By opening the purge valve 33, the concentration of impurities in the hydrogen off-gas in the circulation path 23 decreases, and the concentration of hydrogen in the hydrogen off-gas supplied in circulation increases.

  The refrigerant piping system 5 includes a refrigerant channel 41 communicating with the cooling channel in the fuel cell 2, a cooling pump 42 provided in the refrigerant channel 41, and a radiator 43 that cools the refrigerant discharged from the fuel cell 2. And a bypass flow path 44 that bypasses the radiator 43 and a switching valve 45 that sets the flow of cooling water to the radiator 43 and the bypass flow path 44. The cooling pump 42 circulates and supplies the refrigerant in the refrigerant passage 41 to the fuel cell 2 by driving the motor 42a.

  The control unit 7 is configured as a microcomputer including a CPU, a ROM, and a RAM inside. The CPU executes a desired calculation according to the control program, and performs various processes and controls such as opening and closing of a valve body 18a by a drive unit 18b described later.

  The ROM stores control programs and control data processed by the CPU. The RAM is mainly used as various work areas for control processing. The control unit 7 inputs detection signals such as various pressure sensors, temperature sensors, and outside air temperature sensors used in the gas systems 3 and 4 and the refrigerant system 5, and outputs control signals to each component.

  The humidification module 15 humidifies the oxidizing gas by, for example, replenishing the oxidizing gas supplied to the fuel cell 2 with moisture supplied from the outside. The humidifying module 15 includes an upstream pipe 11a for supplying an oxidizing gas to the humidifying module 15 and an oxidizing gas humidified in the humidifying module 15 for discharging the humidifying module 15 from the humidifying module 15 and supplying it to the fuel cell 2. The downstream side pipe 11b is connected. The upstream side pipe 11 a and the downstream side pipe 11 b communicate with each other via the humidification module 15 and constitute the supply path (pipe) 11 described above.

  Between the upstream side pipe 11a and the downstream side pipe 11b, a communication path 17 is provided on the upstream side of the humidification module 15 so as to communicate with the upstream side pipe 11a and the downstream side pipe 11b. The communication path 17 is provided with a valve 18 that adjusts the open / closed state of the communication path 17. The communication passage 17 and the valve 18 are an embodiment of the adjusting means according to the present invention, and a part or all of the oxidizing gas flowing in the upstream pipe 11a is bypassed from the humidification module 15 as necessary, and then the downstream side. A bypass circuit that flows through the pipe 11b is configured.

  The humidifying device 19 of the present embodiment includes the upstream side pipe 11a, the downstream side pipe 11b, the humidifying module 15, the communication path 17, and the valve 18.

  As shown in FIGS. 2 and 3, the valve 18 is disposed higher in the direction of gravity than the humidification module 15. Further, the upstream pipe 11a and the downstream pipe 11b disposed between the humidification module 15 and the valve 18 are extended obliquely upward from the humidification module 15 and then bent, and are arranged substantially horizontally. It is installed. In the middle of both pipes 11a and 11b arranged substantially horizontally, a valve 18 made of, for example, an electromagnetic valve, provided with a valve body 18a and a drive unit 18b for driving the valve body 18a is provided. .

  The upstream pipe 11a is arranged higher in the direction of gravity than the downstream pipe 11b, and the communication path 17 is provided so as to connect both pipes 11a and 11b having different heights. The valve body 18a is provided so as to open and close a connection (communication) portion between the downstream side pipe 11b and the communication passage 17, and can be driven by a drive unit 18b such as a solenoid. The drive unit 18b operates based on a control signal output from the control unit 7.

  When it is necessary to reduce the humidification amount of the oxidizing gas supplied to the fuel cell 2, the valve body 18 a is driven so as to open a connection portion between the downstream side pipe 11 b and the communication path 17. When the valve body 18a is opened, part or all of the oxidizing gas bypasses the humidification module 15 having a relatively large pressure loss, depending on the open / closed state (opening degree). The bypassed oxidizing gas joins the downstream pipe 11 b through the communication path 17 and is supplied to the fuel cell 2 without being added (humidified) with the humidifying module 15.

  In the fuel cell system 1 configured as described above, the valve 18 and the communication passage 17 provided by the valve 18 are provided at a position higher than the humidification module 15. Even when used in a low temperature environment, water remaining in the humidification module 15 does not flow into the valve 18 and the communication passage 17 disposed above the humidification module 15 in the gravitational direction when the operation is stopped.

  Therefore, even if the outside air temperature falls below the freezing temperature of water (for example, 0 ° C.), the occurrence of malfunction due to the consolidation of the valve 18 (valve element 18a) is suppressed. As described above, according to the fuel cell system 1 described above, it is possible to operate the valve 18 attached to the humidification module 15 without any trouble even in winter or cold regions, so that low temperature startability can be improved. Can do.

  In addition, the said embodiment is an illustration for demonstrating this invention, This invention is not limited to this, A change can be suitably added unless it deviates from the summary. For example, the humidifier 19 of the above embodiment humidifies the oxidizing gas supplied to the fuel cell 2, but instead of or in addition to humidifying the oxidizing gas, the fuel gas supplied to the fuel cell 2 is used. It may be humidified.

1 is a configuration diagram schematically showing one embodiment of a fuel cell system according to the present invention. FIG. It is the schematic for demonstrating the positional relationship of the humidification module provided in the fuel cell system of FIG. 1, the piping connected to this humidification module, and the valve provided in this piping. It is a perspective view which shows the humidification module provided in the fuel cell system of FIG. 1, the piping connected to this humidification module, and the valve provided in this piping.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Fuel cell system, 2 ... Fuel cell, 11 ... Supply path (piping), 11a ... Upstream piping, 11b ... Downstream piping, 15 ... Humidification module, 17 ... Communication path (adjustment means), 18 ... Valve (adjustment) Means), 19 ... Humidifier

Claims (3)

A humidification module that humidifies and discharges the supplied gas;
Piping connected to the humidification module;
A humidifying device provided with adjusting means for adjusting a gas supply amount to the humidifying module provided in the pipe,
The humidifying device in which the adjusting means is disposed higher in the gravity direction than the humidifying module. The pipe comprises an upstream pipe for supplying gas to the humidification module, and a downstream pipe for discharging gas humidified by the humidification module from the humidification module.
The said adjustment means is provided with the communicating path which connects the said upstream piping and the said downstream piping in the upstream of the said humidification module, and the valve which adjusts the open / close state of the said communicating path. The humidifier described. A fuel cell system comprising: a fuel cell that generates electricity by an electrochemical reaction between an oxidizing gas and a fuel gas; and a humidifier that humidifies at least one of the oxidizing gas and the fuel gas supplied to the fuel cell,
A fuel cell system in which the humidifier according to claim 1 or 2 is used as the humidifier.

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