Fuel cell system and vehicle

Abstract

The present invention relates to a fuel cell system and a vehicle, in which the generation of white mist and splashing water can be suppressed in the fuel cell system, and the fuel gas can be diluted and the exhaust and liquid discharge to the outside of the system can be realized. In the fuel cell system, a gas-liquid separator is respectively provided in the anode exhaust gas flow path and the cathode exhaust gas flow path, and on the basis of separating the exhaust path and the liquid discharge path, the gas in the anode exhaust gas is mixed with the gas in the cathode exhaust gas for exhaust, and on the other hand, the liquid in the anode exhaust gas is mixed with the liquid in the cathode exhaust gas for liquid discharge. The gas-liquid separator provided in the anode exhaust gas flow path controls the liquid level by a control unit, and the liquid level does not become zero during liquid discharge. Thus, in the gas-liquid separator, the gas in the anode exhaust gas can be suppressed from flowing out to the liquid discharge side. In this way, by independently providing the exhaust system and the liquid discharge system, the generation of white mist and splashing water can be suppressed. In addition, by mixing the anode exhaust gas with the cathode exhaust gas in the exhaust system, the fuel gas can be diluted.

Description

Technical Field

[0001] The present application discloses a fuel cell system and a vehicle. Background Art

[0002] When power is generated by a fuel cell, water is discharged from the fuel cell to the outside of the system. When water is discharged from the fuel cell to the outside of the system, there are cases where the generation of white mist becomes a problem. For example, white mist may be generated in the following cases. That is, when water captured by the gas-liquid separator provided in the anode exhaust gas flow path is mixed with the cathode exhaust gas flow path, it is vaporized by the high-temperature cathode exhaust gas. When the vaporized water is discharged from the cathode exhaust gas flow path to the outside of the system, it is cooled by the external temperature and becomes a white mist.

[0003] In the technology disclosed in Patent Document 1, the anode exhaust gas discharged from the fuel cell is separated into gas and liquid by a gas-liquid separator, and the liquid is discharged to the outside air along with the cathode exhaust gas, and when it is determined that white mist is generated when the cathode exhaust gas is discharged to the outside air, the flow rate and flow velocity of the cathode exhaust gas are controlled. In this way, the generation of white mist can be suppressed.

[0004] Furthermore, Patent Documents 2 and 3 also disclose technologies for separating exhaust gas from a fuel cell into gas and liquid using a gas-liquid separator.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2009-037870

[0006] Patent Document 2: Japanese Patent Application Publication No. 2011-170978

[0007] Patent Document 3: Japanese Patent Application Publication No. 2017-174753

[0008] The technology disclosed in Patent Document 1 is a technology that attempts to mix the moisture in the anode exhaust gas with the cathode exhaust gas to dilute all the drainage from the fuel cell using the cathode exhaust gas. However, depending on the operating conditions of the fuel cell, the flow rate of the cathode exhaust gas may change, and there is a concern that the moisture cannot be properly diluted using the cathode exhaust gas. In addition, when the flow rate of the cathode exhaust gas is increased for dilution, the total volume of the gas increases, so although it can be considered that the white mist itself becomes thinner, there is a concern that the fuel efficiency will decrease.

[0009] When water is discharged from the fuel cell to the outside of the system, it is preferred that in addition to suppressing the generation of white mist as described above, the scattering of water around the fuel cell (splashing) is also suppressed. Splashing becomes a problem, for example, when the fuel cell is mounted on a vehicle. That is, when water is discharged from the fuel cell while the vehicle is running, it is necessary to avoid splashing the water onto the following vehicle as much as possible. In the technology disclosed in Patent Document 1, water is discharged to the outside of the system together with the cathode exhaust gas as described above, and the water and the cathode exhaust gas are scattered together, which easily causes the problem of splashing.

[0010] Furthermore, in addition to the above-mentioned water, the anode exhaust gas of the fuel cell may also include fuel gas. When the fuel gas is discharged to the outside of the system, it is preferable to dilute the fuel gas as much as possible. Summary of the invention

[0011] As one of the means for solving the above-mentioned problems, the present application discloses a fuel cell system, which comprises:

[0012] Fuel cells;

[0013] A first flow path, in which anode exhaust gas is discharged from the fuel cell;

[0014] A second flow path for receiving cathode exhaust gas discharged from the fuel cell;

[0015] an anode gas-liquid separator connected to the first flow path and separating the anode exhaust gas into an anode separation gas and an anode separation liquid;

[0016] a cathode gas-liquid separator connected to the second flow path and separating the cathode exhaust gas into cathode separation gas and cathode separation liquid;

[0017] A third flow path, in which the anode separation gas is discharged from the anode gas-liquid separator;

[0018] a fourth flow path, into which the anode separated liquid is discharged from the anode gas-liquid separator;

[0019] a fifth flow path, in which the cathode separated gas is discharged from the cathode gas-liquid separator;

[0020] a sixth flow path, into which the cathode separated liquid is discharged from the cathode gas-liquid separator;

[0021] The first connection portion between the third flow path and the fifth flow path is used for mixing the anode separation gas and the cathode separation gas;

[0022] a seventh flow path for discharging the mixed anode separation gas and cathode separation gas from the first connection portion;

[0023] The second connection portion between the fourth flow path and the sixth flow path is used for mixing the anode separation liquid and the cathode separation liquid;

[0024] an eighth flow path for discharging the mixed anode separated liquid and cathode separated liquid from the second connecting portion; and

[0025] A control unit controls the liquid level of the anode gas-liquid separator.

[0026] The anode separated liquid is discharged from the lower part of the anode gas-liquid separator.

[0027] The control unit performs control so that the liquid level in the anode gas-liquid separator does not become zero when the anode separated liquid is discharged from the anode gas-liquid separator.

[0028] In the fuel cell system of the present disclosure, the anode gas-liquid separator may include a liquid level sensor.

[0029] In the fuel cell system of the present disclosure, the anode off-gas may contain hydrogen.

[0030] In the fuel cell system of the present disclosure, the fuel cell may be a solid polymer fuel cell.

[0031] As one of means for solving the above-mentioned problems, the present application discloses a vehicle including the fuel cell system of the present disclosure.

[0032] In the vehicle of the present disclosure, the drain port of the fuel cell system may be provided at the center in the width direction of the vehicle in a downward manner.

[0033] In the fuel cell system disclosed in the present invention, the anode separation gas contained in the anode exhaust gas is mixed with the cathode separation gas contained in the cathode exhaust gas and discharged outside the system. On the other hand, the anode separation liquid contained in the anode exhaust gas is mixed with the cathode separation liquid contained in the cathode exhaust gas and discharged outside the system. In addition, by controlling the liquid level of the anode gas-liquid separator, the mixing of the anode separation gas into the drainage system can be suppressed. In this way, in the fuel cell system disclosed in the present invention, since the exhaust system and the drainage system are independently provided, it is difficult to produce the above-mentioned white mist and splashing problems. In addition, in the fuel cell system disclosed in the present invention, by mixing the anode separation gas with the cathode separation gas, the fuel gas in the anode separation gas can be diluted. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram for explaining the structure of the fuel cell system 100 .

[0035] Figure 2 This is a schematic diagram for explaining an example of another configuration included in the fuel cell system 100 .

[0036] Figure 3A2 is a schematic diagram for explaining the vehicle 200. 2 is a diagram of the vehicle 200 as seen from the side.

[0037] Figure 3B 2 is a schematic diagram for explaining the vehicle 200. The vehicle 200 is viewed from the rear.

[0038] Description of reference numerals:

[0039] 1…fuel cell; 11…first flow path; 12…second flow path; 13…third flow path; 14…fourth flow path; 15…fifth flow path; 16…sixth flow path; 17…seventh flow path; 18…eighth flow path; 19…anode gas supply flow path; 20…cathode gas supply flow path; 20a…bypass flow path; 21…anode gas-liquid separator; 21a…drain valve; 21b…exhaust valve; 22…cathode gas-liquid separator; 31…first connection portion; 32…second connection portion; 40…control portion; 50…injector; 51, 52…coolant flow path; 53, 54…coolant branch flow path; 60…compressor; 61…heat exchanger; 62…intercooler; 70…humidifier; 81…flow regulating valve; 82, 83, 84…valves; 100…fuel cell system; 101…drain port; 200…vehicle. DETAILED DESCRIPTION

[0040] 1. Fuel cell system

[0041] Figure 1 The structure of the fuel cell system 100 is briefly shown in FIG. Figure 1 As shown, the fuel cell system 100 comprises:

[0042] Fuel cell 1;

[0043] The first flow path 11 discharges the anode exhaust gas from the fuel cell 1;

[0044] The second flow path 12 discharges cathode exhaust gas from the fuel cell 1;

[0045] The anode gas-liquid separator 21 is connected to the first flow path 11 and separates the anode exhaust gas into an anode separation gas and an anode separation liquid;

[0046] The cathode gas-liquid separator 22 is connected to the second flow path 12 and separates the cathode exhaust gas into cathode separation gas and cathode separation liquid;

[0047] The third flow path 13 discharges the anode separated gas from the anode gas-liquid separator 21;

[0048] The fourth flow path 14 discharges the anode separated liquid from the anode gas-liquid separator 21;

[0049] The fifth flow path 15 discharges the cathode separated gas from the cathode gas-liquid separator 22;

[0050] The sixth flow path 16 discharges the cathode separated liquid from the cathode gas-liquid separator 22;

[0051] The first connection portion 31 between the third flow path 13 and the fifth flow path 15 is used for mixing the anode separated gas and the cathode separated gas;

[0052] The seventh flow path 17 discharges the mixed anode separation gas and cathode separation gas from the first connection portion 31;

[0053] The second connection portion 32 between the fourth flow path 14 and the sixth flow path 16 is used for mixing the anode separated liquid and the cathode separated liquid;

[0054] The eighth flow path 18 discharges the mixed anode separated liquid and cathode separated liquid from the second connecting portion 32; and

[0055] The control unit 40 controls the liquid level of the anode gas-liquid separator 21 .

[0056] The anode separated liquid is discharged from the lower portion of the anode gas-liquid separator 21 .

[0057] The control unit 40 performs control so that the liquid level in the anode gas-liquid separator 21 does not reach zero when the anode separated liquid is discharged from the anode gas-liquid separator 21 .

[0058] 1.1 Fuel Cell

[0059] The fuel cell 1 receives supply of cathode gas and anode gas to generate electricity. The cathode gas can be an oxygen-containing gas such as air. On the other hand, the anode gas can be hydrogen, or a fuel gas other than hydrogen. As a specific example of the fuel cell 1, a solid polymer fuel cell (PEFC) can be cited. The operating temperature of PEFC is relatively low, and it is considered that the above-mentioned white mist and splashing problems are prone to occur, but according to the fuel cell system 100 disclosed in the present invention, the white mist and splashing can be suppressed. The fuel cell 1 can also be a fuel cell stack. The connection method of the fuel cell 1 and the flow path described later is not particularly limited, for example, as long as it is a general piping connection.

[0060] 1.2 1st flow path

[0061] The anode exhaust gas is discharged from the fuel cell 1 to the first flow path 11. In addition, the first flow path 11 is connected to the anode gas-liquid separator 21. That is, the first flow path 11 is a flow path for guiding the anode exhaust gas discharged from the fuel cell 1 to the anode gas-liquid separator 21. For example, one end of the upstream side of the first flow path 11 can be connected to the anode exhaust gas outlet of the fuel cell 1, and the other end of the downstream side can be connected to the anode gas-liquid separator 21. The anode exhaust gas may contain the above-mentioned hydrogen, for example. In the fuel cell system 100 of the present disclosure, even if the anode exhaust gas contains hydrogen, the hydrogen can be diluted and exhausted. Alternatively, the anode exhaust gas may also contain a fuel gas other than hydrogen. Furthermore, water may also be contained.

[0062] 1.3 Second flow path

[0063] The cathode exhaust gas is discharged from the fuel cell 1 to the second flow path 12. In addition, the second flow path 12 is connected to the cathode gas-liquid separator 22. That is, the second flow path 12 is a flow path for guiding the cathode exhaust gas discharged from the fuel cell 1 to the cathode gas-liquid separator 22. For example, one end of the upstream side of the second flow path 12 can be connected to the cathode exhaust gas outlet of the fuel cell 1, and the other end of the downstream side can be connected to the cathode gas-liquid separator 22. The cathode exhaust gas may contain oxygen and water, for example.

[0064] 1.4 3rd flow path

[0065] The anode separation gas is discharged from the anode gas-liquid separator 21 to the third flow path 13. In addition, in order to mix the anode separation gas with the cathode separation gas, the third flow path 13 is connected to the fifth flow path 15 at the first connection portion 31. That is, the third flow path 13 is a flow path for guiding the anode separation gas discharged from the anode gas-liquid separator 21 to the cathode separation gas discharge flow path, that is, the fifth flow path 15. For example, one end of the upstream side of the third flow path 13 can be connected to the exhaust valve 21b provided in the anode gas-liquid separator 21, and the other end of the downstream side can be connected to the first connection portion 31. The anode separation gas may contain, for example, hydrogen or a fuel gas other than hydrogen. In addition, the anode separation gas may contain water, but the water content is less than that of the above-mentioned anode exhaust gas, and it is difficult to cause problems such as white mist and splashing water.

[0066] 1.5 4th flow path

[0067] Anode separated liquid is discharged from the anode gas-liquid separator 21 to the fourth flow path 14. In addition, in order to mix the anode separated liquid with the cathode separated liquid, the fourth flow path 14 is connected to the sixth flow path 16 at the second connection portion 32. That is, the fourth flow path 14 is a flow path for guiding the anode separated liquid discharged from the anode gas-liquid separator 21 to the cathode separated liquid discharge flow path, that is, the sixth flow path 16. For example, one end of the upstream side of the fourth flow path 14 can be connected to the drain valve 21a provided in the anode gas-liquid separator 21, and the other end of the downstream side can be connected to the second connection portion 32. The anode separated liquid may contain water, for example. In addition, in the fuel cell system 100, as described later, the liquid level control of the control unit 40 is used to suppress the anode separated gas from flowing into the fourth flow path 14 together with the anode separated liquid. That is, in the fuel cell system 100 of the present disclosure, only the anode separated liquid actually flows in the fourth flow path 14.

[0068] 1.6 5th flow path

[0069] The cathode separated gas is discharged from the cathode gas-liquid separator 22 to the fifth flow path 15. In addition, as described above, in order to mix the anode separated gas with the cathode separated gas, the third flow path 13 and the fifth flow path 15 are connected at the first connection portion 31. Thus, the cathode separated gas discharged from the cathode gas-liquid separator 21 can be used to dilute the anode separated gas discharged from the anode gas-liquid separator 21 and discharge it to the outside of the system. For example, one end of the upstream side of the fifth flow path 15 can be connected to the exhaust valve (not shown) provided in the cathode gas-liquid separator 22, and the first connection portion 31 with the third flow path 13 can be present at the other end of the downstream side of the fifth flow path 15, and the seventh flow path 17 is provided on the downstream side of the first connection portion 31, and the downstream side of the seventh flow path 17 is open to the outside of the system. The cathode separated gas may contain oxygen, for example. In addition, the cathode separated gas may contain water, but the water content is less than that of the cathode exhaust gas described above, and it is difficult to cause the problem of white mist and splashing water.

[0070] 1.7 6th flow path

[0071] The cathode separated liquid is discharged from the cathode gas-liquid separator 22 to the sixth flow path 16. In addition, as described above, in order to mix the anode separated liquid and the cathode separated liquid, the fourth flow path 14 is connected to the sixth flow path 16 at the second connection portion 32. Thus, the anode separated liquid discharged from the anode gas-liquid separator 21 and the cathode separated liquid discharged from the cathode gas-liquid separator 22 can be discharged to the outside of the system together. For example, one end of the upstream side of the sixth flow path 16 can be connected to a drain valve (not shown) provided in the cathode gas-liquid separator 22, and a second connection portion 32 with the fourth flow path 14 is present at the other end on the downstream side of the sixth flow path 16, and an eighth flow path 18 is provided on the downstream side of the second connection portion 32, and the downstream side of the eighth flow path 18 is open to the outside of the system. The cathode separated liquid may contain water, for example. In addition, gases such as oxygen may be mixed into the cathode separated liquid.

[0072] 1.8 7th flow path and 8th flow path

[0073] As described above, the seventh flow path 17 is provided on the downstream side of the first connection portion 31, and the eighth flow path 18 is provided on the downstream side of the second connection portion 32. The mixed anode separation gas and cathode separation gas are discharged from the first connection portion 31 to the seventh flow path 17. In addition, the mixed anode separation liquid and cathode separation liquid are discharged from the second connection portion 32 to the eighth flow path 18.

[0074] 1.9 First connection part and second connection part

[0075] The connection method of each flow path in the first connection portion 31 and the second connection portion 32 is not particularly limited, and for example, a general piping connection can be adopted.

[0076] 1.10 Anode gas-liquid separator

[0077] The anode gas-liquid separator 21 is connected to the first flow path 11 and separates the anode exhaust gas into an anode separated gas and an anode separated liquid. The anode gas-liquid separator 21 discharges the anode separated liquid from its lower portion.

[0078] In the present application, the position of the "lower part" of the anode gas-liquid separator 21 is actually the same as the position where the liquid level is zero in the anode gas-liquid separator 21. That is, when the liquid level inside the anode gas-liquid separator 21 exceeds zero, at least the lower part of the anode gas-liquid separator 21 is filled with the anode separation liquid. In other words, as long as the liquid level inside the anode gas-liquid separator 21 exceeds zero, the anode separation liquid functions as a barrier between the anode gas-liquid separator 21 and the fourth flow path 14, and it is difficult for the anode separation gas to flow into the fourth flow path 14.

[0079] like Figure 1As shown, the anode gas-liquid separator 21 may have a drain port at the lower part, and the drain port can be opened and closed by a drain valve 21a. In addition, the anode gas-liquid separator 21 may have an exhaust port in a portion other than the lower part, and the exhaust port can be opened and closed by an exhaust valve 21b. The position of the drain valve 21a in the anode gas-liquid separator 21 is the lower part of the anode gas-liquid separator 21 as described above. On the other hand, the specific position of the exhaust valve 21b in the anode gas-liquid separator 21 is not particularly limited, as long as it is located above the drain valve 21a provided at the lower part. When the internal space of the anode gas-liquid separator 21 is divided into an upper half and a lower half, an exhaust valve 21b can be provided in the space of the upper half, and a drain valve 21a can be provided at the lower part of the lower half. In the anode gas-liquid separator 21, for example, a structure similar to that of the gas-liquid separator disclosed in Patent Document 2 can be adopted. Furthermore, in order to circulate and reuse the hydrogen in the anode separated gas, the anode gas-liquid separator 21 may be provided with an additional hydrogen discharge path, and the downstream of the hydrogen discharge path may be connected to the ejector 50 .

[0080] 1.11 Cathode gas-liquid separator

[0081] The cathode gas-liquid separator 22 is not particularly limited as long as it can separate gas and liquid. As the cathode gas-liquid separator 22, any of the known gas-liquid separators can be used. However, in the cathode gas-liquid separator 22, from the viewpoint of suppressing the cathode separated gas from mixing into the fifth flow path 15, as the cathode gas-liquid separator 22, a gas-liquid separator having the same structure as the anode gas-liquid separator 21 can be used. In addition, in the cathode gas-liquid separator 22, the liquid level can be controlled by the control unit 40.

[0082] 1.12 Control Unit

[0083] The control unit 40 controls so that the liquid level in the anode gas-liquid separator 21 does not reach zero when the anode separated liquid is discharged from the anode gas-liquid separator 21. The control unit 40 may be configured similarly to a general control mechanism. That is, the control unit 40 may include a CPU, a RAM, a ROM, and the like.

[0084] As described above, when the anode gas-liquid separator 21 is drained, the liquid level inside the anode gas-liquid separator 21 is maintained above zero, so that the anode gas-liquid separator 21 and the fourth flow path 14 are blocked by the anode separation liquid. As a result, the anode separation gas can be suppressed from flowing into the fourth flow path 14, and the exhaust system and the drain system on the anode side can be more clearly separated.

[0085] The specific control action of the control unit 40 is not particularly limited. For example, the anode gas-liquid separator 21 may be provided with a liquid level sensor. When the drain valve 21a of the anode gas-liquid separator 21 is opened to drain the liquid, the liquid level sensor may be used to monitor the displacement of the liquid level of the anode gas-liquid separator 21, and the information of the liquid level obtained by the liquid level sensor is transmitted to the control unit 40. In this case, the control unit 40 may determine whether the liquid level obtained by the liquid level sensor is above the threshold value. When the liquid level exceeds the threshold value, the drain valve 21a is maintained in an open state to continue the drainage to the fourth flow path 14. On the other hand, when the liquid level obtained by the liquid level sensor is lower than the threshold value, the drain valve 21a is closed to stop the drainage of the anode separated liquid. Thus, when the anode separated liquid is discharged from the anode gas-liquid separator 21, the liquid level in the anode gas-liquid separator 21 can be maintained above zero. Alternatively, the liquid level of the anode gas-liquid separator 21 may be indirectly controlled without using a liquid level sensor.

[0086] 1.13 Other structures

[0087] In addition to the above-described configuration, the fuel cell system 100 may further include, for example, the following configuration.

[0088] 1.13.1 Anode gas supply flow path

[0089] As described above, the fuel cell 1 receives the supply of anode gas to generate electricity. Figure 1 as well as Figure 2 As shown, the fuel cell system 100 may include an anode gas supply flow path 19 for supplying anode gas to the fuel cell 1 from the outside. The anode gas supply flow path 19 may be configured, for example, such that one end on the upstream side is connected to the anode gas source, and the other end on the downstream side is connected to the anode gas supply port of the fuel cell 1. The type of the anode gas source is not particularly limited. A tank containing fuel gas, an alloy absorbing fuel gas, etc. may be used. The type of the anode gas supply flow path 19 may be the same as in the past. In addition, as Figure 1 as well as Figure 2 As shown, the anode gas supply flow path 19 may include various devices such as an ejector 50 and a circulation pump.

[0090] 1.13.2 Cathode gas supply flow path

[0091] As described above, the fuel cell 1 receives the supply of cathode gas to generate electricity. Figure 1 as well as Figure 2As shown, the fuel cell system 100 may include a cathode gas supply flow path 20 for supplying cathode gas to the fuel cell 1 from the outside. The cathode gas supply flow path 20 may be configured, for example, such that one end on the upstream side is connected to the cathode gas source, and the other end on the downstream side is connected to the cathode gas supply port of the fuel cell 1. The cathode gas source is not particularly limited. When air is used as the cathode gas, one end on the upstream side of the cathode gas supply flow path 20 may be open to the atmosphere.

[0092] 1.13.3 Bypass Flow

[0093] like Figure 2 As shown, the fuel cell system 100 may include a bypass flow path 20a branching from the cathode gas supply flow path 20 and connected to the cathode exhaust gas discharge flow path (the fifth flow path 15). For example, when the flow rate and pressure of the cathode gas in the flow path 20 are too large, the bypass flow path 20a can function as a flow path for discharging an excessive amount of cathode gas from the flow path 20 to the fifth flow path 15. In addition, when the compressor 60 described later is a turbo compressor (such as a centrifugal compressor), the bypass flow path 20a can also function as a flow path for avoiding surge of the turbo compressor. That is, when the cathode gas flow rate required by the fuel cell 1 is lower than the lower limit flow rate of the turbo compressor, the bypass flow path 20a is used to maintain the cathode gas flow rate of the turbo compressor at a lower limit flow rate to avoid surge, and by diverting a part of the cathode gas through the bypass flow path 20a, the cathode gas flow rate supplied to the fuel cell 1 can be adjusted. Furthermore, when it is desired to reduce or cut off the supply of cathode gas to the fuel cell 1 for some reason, the bypass flow path 20a can also function as a flow path for discharging the cathode gas. Figure 2 As shown, in the fuel cell 100 , the flow rate of the cathode gas in the bypass flow path 20 a can be adjusted by the flow rate adjustment valve 81 .

[0094] 1.13.4 Compressor

[0095] like Figure 2As shown, a compressor 60 can be provided in the cathode gas supply flow path 20. The compressor 60 can be arranged at a position closer to the upstream side than the bypass flow path 20a. The compressor 60 has the function of increasing the pressure of the cathode gas supplied to the fuel cell 1. The type of the compressor 60 is not particularly limited. The compressor 60 can be, for example, a turbine type, a scroll type, or a spiral roots type. In addition, a compressor 60 with an expander can be used, and the compressor 60 with the expander is connected to the 5th flow path 15. As described above, in the fuel cell system 100 disclosed in the present invention, since the water content in the 5th flow path 15 is reduced by performing gas-liquid separation on the cathode exhaust gas, the mixing of liquid water into the expander can be suppressed.

[0096] 1.13.5 Coolant Flow and Heat Exchanger

[0097] like Figure 2 As shown, in the fuel cell system 100, coolant flow paths 51 and 52 for circulating coolant can be provided between the fuel cell 1 and the heat exchanger 61. The coolant flow paths 51 and 52 and the heat exchanger 61 can be configured in the same manner as in the past. For example, a radiator, an intercooler, an oil cooler, or a combination thereof can be used as the heat exchanger 61. In the case of considering mounting on a vehicle, the heat exchanger 61 can be a heat exchanger including at least a radiator.

[0098] 1.13.6 Intercooler

[0099] like Figure 2 As shown, in the fuel cell system 100, an intercooler 62 can be provided on the downstream side of the compressor 60. That is, the cathode gas whose temperature rises due to the pressure increase of the compressor 60 can be cooled by the intercooler 62 while maintaining a predetermined pressure. The intercooler 62 can be connected to the above-mentioned coolant flow paths 51, 52, for example. That is, by diverting a part of the coolant circulating in the coolant flow paths 51, 52 to the intercooler 62 via the flow path 53, the required cooling performance in the intercooler 62 can be easily ensured. The coolant supplied to the intercooler 62 can be returned to the coolant flow path 52 via the flow path 54.

[0100] 1.13.7 Humidifier

[0101] like Figure 2 As shown in FIG. 1 , in the fuel cell system 100, a humidifier 70 may be provided in the cathode gas supply flow path 20. The humidifier 70 may be disposed between the fuel cell 1 and the bypass flow path 20a. Figure 2As shown, the humidifier 70 can be connected to both the cathode gas supply flow path 20 and the cathode exhaust gas discharge flow path (fifth flow path 15). Specifically, the humidifier 70 can use the moisture in the cathode exhaust gas discharged from the fuel cell 1 to the fifth flow path 15 to humidify the inside of the fuel cell 1. In other words, in the fuel cell system 100, moisture can be circulated through the fuel cell 1, the cathode gas supply flow path 20, the fifth flow path 15, and the humidifier 70.

[0102] 1.13.8 Valve

[0103] Each flow path may be provided with valves other than those mentioned above. Figure 2 As shown, the fifth flow path 15 may be provided with a valve 82 at a position upstream of the bypass flow path 20a (between the fuel cell 1 and the bypass flow path 20a). By adjusting the opening of the valve 82, the flow rate and pressure of the cathode gas can be adjusted. For example, when the pressure inside the fuel cell 1 decreases, the opening of the valve 82 may be reduced and the pressure inside the cathode gas supply flow path 20 may be increased by the compressor 60.

[0104] like Figure 2 As shown, the cathode gas supply flow path 20 may be provided with a valve 83 at a position downstream of the bypass flow path 20a (between the fuel cell 1 and the bypass flow path 20a). By adjusting the opening of the valve 83, the flow rate and pressure of the cathode gas can be adjusted. For example, when the cathode gas flow rate supplied to the fuel cell 1 is larger than the required amount, the cathode gas flow rate supplied to the fuel cell 1 can be reduced by reducing the opening of the valve 83 and increasing the opening of the flow regulating valve 81 without changing the cathode gas flow rate of the compressor 60.

[0105] like Figure 2 As shown, when the humidifier 70 is provided in the fuel cell system 100, the cathode gas supply flow path 20 may include a flow path bypassing the humidifier 70, and a valve 84 may be provided in the bypass flow path. Figure 2 As shown in FIG. 8 , the valve 83 may be disposed at a position upstream of the humidifier 70 (between the bypass flow path and the humidifier 70). Figure 2 As shown, when the interior of the fuel cell 1 is humidified by the humidifier 70, the opening of the valve 83 can be increased and the opening of the valve 84 can be decreased. When humidification by the humidifier 70 is not required, the opening of the valve 83 can be decreased and the opening of the valve 84 can be increased.

[0106] In addition, in the fuel cell system 100, the opening and closing of the valves 81 to 84 can be controlled by the above-mentioned control unit 40. That is, the control unit 40 only needs to control the liquid level in the anode gas-liquid separator 21 at least when the anode gas-liquid separator 21 is drained, and in addition, the gas flow rate in each flow path, the humidity of the fuel cell 1, and other controls can also be performed.

[0107] 1.13.9 Others

[0108] The fuel cell system 100 may include other structures not shown. For example, the fuel cell system 100 may include a cleaner for removing dust and dirt contained in the cathode gas before the cathode gas flows into the compressor 60. In addition, of course, wiring extending from the fuel cell 1 to the outside may also be included. These structures may be the same as those in the past.

[0109] also, Figure 2 The structures shown are examples of structures that the fuel cell system of the present disclosure can have. The fuel cell system of the present disclosure can have Figure 1 The basic structure shown is omitted Figure 2 It may also include a part of each structure shown in the figure. Figure 2 Structures other than those shown.

[0110] 2. Vehicles

[0111] The technology disclosed herein also has an aspect as a vehicle. Figure 3A as well as Figure 3B As shown, a vehicle 200 of the present disclosure includes a fuel cell system 100 .

[0112] The mounting position of the fuel cell system 100 in the vehicle is not particularly limited. Figure 3A As shown, the fuel cell system 100 is mounted in the front part of the vehicle 200. Alternatively, the fuel cell system may be mounted in the center of the front-rear direction of the vehicle 200 or in the rear of the vehicle. In addition, in the vehicle 200, the position of the outlet of the waste liquid discharged from the fuel cell system 100 is not particularly limited. Figure 3B As shown, when the drain port 101 of the fuel cell system 100 is disposed downwardly at the center of the width direction of the vehicle 200, it is possible to prevent the waste liquid from the fuel cell system 100 from contacting the wheels when the vehicle is running, and to suppress the scattering of the waste liquid. Furthermore, it is possible to suppress the waste liquid from accumulating in the rut-forming portion of the road surface, and to suppress the freezing of the road surface at the rut-forming portion and the skidding of the vehicle caused by the freezing in cold regions. The drain port 101 can be disposed, for example, at the downstream end of the eighth flow path 18 described above.

[0113] In the vehicle 200, the position of the outlet of the exhaust gas discharged from the fuel cell system 100 is not particularly limited. It can be set at a position that has little impact on other vehicles, pedestrians, passengers, etc. For example, the outlet of the exhaust body can be set downward in the central part of the front-to-back direction of the vehicle 200. The outlet of the exhaust gas can also be set at the end of the downstream side of the above-mentioned 5th flow path 15. In addition, in the fuel cell system 100 disclosed in the present invention, since the exhaust system and the drainage system are independent, it is difficult to produce problems such as white mist and splashing caused by the gas discharged from the exhaust system. Therefore, even if the outlet of the exhaust gas is arranged at the rear part of the vehicle, the impact on the following vehicle is less.

[0114] As described above, according to the fuel cell system 100 of the present disclosure, the gas (anode separation gas) contained in the anode exhaust gas and the gas (cathode separation gas) contained in the cathode exhaust gas can be mixed and discharged outside the system. On the other hand, the liquid water (anode separation liquid) contained in the anode exhaust gas and the liquid water (cathode separation liquid) contained in the cathode exhaust gas can be mixed and discharged outside the system. In addition, by controlling the liquid level of the anode gas-liquid separator 21, the mixing of the anode separation gas into the drainage system can be suppressed. In this way, in the fuel cell system 100 of the present disclosure, since the exhaust system and the drainage system are independently provided, the amount of water in the exhaust system can be reduced, so even if the flow rate of the exhaust gas in the exhaust system is not controlled, it is difficult to generate white mist. In addition, by reducing the amount of water in the exhaust system, it is difficult for water to fly together with the exhaust gas and it is difficult to cause the problem of splashing water. In addition, in the fuel cell system 100 of the present disclosure, by mixing the anode separation gas with the cathode separation gas, the fuel gas in the anode separation gas can be diluted.

Claims

1. A fuel cell system, wherein: have: Fuel cells; A first flow path, in which anode exhaust gas is discharged from the fuel cell; A second flow path for receiving cathode exhaust gas discharged from the fuel cell; an anode gas-liquid separator connected to the first flow path and separating the anode exhaust gas into an anode separation gas and an anode separation liquid; a cathode gas-liquid separator connected to the second flow path and separating the cathode exhaust gas into cathode separation gas and cathode separation liquid; A third flow path, in which the anode separation gas is discharged from the anode gas-liquid separator; a fourth flow path, into which the anode separated liquid is discharged from the anode gas-liquid separator; a fifth flow path, in which the cathode separated gas is discharged from the cathode gas-liquid separator; a sixth flow path, into which the cathode separated liquid is discharged from the cathode gas-liquid separator; The first connection portion between the third flow path and the fifth flow path is used for mixing the anode separation gas and the cathode separation gas; a seventh flow path for discharging the mixed anode separation gas and cathode separation gas from the first connection portion; The second connection portion between the fourth flow path and the sixth flow path is used for mixing the anode separation liquid and the cathode separation liquid; an eighth flow path for discharging the mixed anode separated liquid and cathode separated liquid from the second connecting portion; A first coolant flow path and a second coolant flow path for circulating the coolant between the fuel cell and the heat exchanger; an anode gas supply flow path for supplying anode gas to the fuel cell from the outside; a cathode gas supply flow path for supplying cathode gas to the fuel cell from the outside; a bypass flow path branched from the cathode gas supply flow path and connected to the fifth flow path; a compressor arranged in the cathode gas supply flow path at a position upstream of the bypass flow path; an intercooler disposed on the downstream side of the compressor, which diverts a portion of the coolant circulating in the first coolant flow path and the second coolant flow path through a ninth flow path and returns the supplied coolant to the second coolant flow path through a tenth flow path; a humidifier, arranged between the fuel cell and the bypass flow path, connected to both the cathode gas supply flow path and the fifth flow path, and humidifying the interior of the fuel cell by using moisture in the cathode exhaust gas discharged from the fuel cell to the fifth flow path; a flow regulating valve for regulating the flow of cathode gas in the bypass flow path; a first valve located upstream of the bypass flow path in the fifth flow path and between the fuel cell and the bypass flow path; A bypass flow path bypassing the humidifier and having a second valve; a third valve provided upstream of the humidifier and between the bypass flow path and the humidifier; and A control unit controls the liquid level of the anode gas-liquid separator. The anode gas-liquid separator has a liquid discharge port at the bottom. The above-mentioned drain port can be opened and closed by a drain valve. The anode separated liquid is discharged from the drain port at the bottom of the anode gas-liquid separator. The control unit performs control so that the liquid level in the anode gas-liquid separator does not become zero when the anode separated liquid is discharged from the anode gas-liquid separator.

2. The fuel cell system according to claim 1, wherein: The above-mentioned anode gas-liquid separator is equipped with a liquid level sensor. The control unit controls to close the drain valve and stop draining the anode separated liquid when the liquid level obtained by the liquid level sensor is lower than a threshold value.

3. The fuel cell system according to claim 1 or 2, wherein: The anode off-gas contains hydrogen.

4. The fuel cell system according to claim 1 or 2, wherein: The above-mentioned fuel cell is a solid polymer fuel cell.

5. A vehicle, wherein: A fuel cell system comprising the fuel cell system according to any one of claims 1 to 4.

6. The vehicle according to claim 5, wherein: The drain port of the fuel cell system is provided at the center in the width direction of the vehicle so as to face downward.

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