Fuel cell system

Abstract

This specification provides a technology that can avoid or suppress the charging of auxiliary equipment. [Solution] The fuel cell system disclosed herein comprises a cooling channel through which cooling water circulates, a fuel cell stack provided on the cooling channel, and a first auxiliary device provided on the cooling channel and including metal parts that come into contact with the cooling water. The cooling channel includes a stack channel in which the fuel cell stack is arranged and a first channel in which the first auxiliary device is arranged. A portion of the first channel is composed of a first metal pipe and a second metal pipe. The first auxiliary device is arranged between the first metal pipe and the second metal pipe in the first channel. The first metal pipe and the second metal pipe are configured to be grounded.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a fuel cell system.

Background Art

[0002] Patent Document 1 discloses a fuel cell system including a cooling flow path through which cooling water circulates, a fuel cell stack provided on the cooling flow path, and auxiliary equipment provided on the cooling flow path and including metal parts that come into contact with the cooling water. The cooling flow path includes a stack flow path in which the fuel cell stack is disposed and an auxiliary equipment flow path in which the auxiliary equipment is disposed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a fuel cell system, auxiliary equipment arranged in the same cooling flow path as the fuel cell stack may be charged through the cooling water. In the fuel cell system of Patent Document 1, the auxiliary equipment is electrically connected to the ground via wiring. That is, the auxiliary equipment is configured to be grounded. This suppresses the charging of the auxiliary equipment. However, it may be difficult to directly ground the auxiliary equipment.

[0005] This specification provides a technology capable of avoiding or suppressing the charging of auxiliary equipment.

Means for Solving the Problems

[0006] In a first aspect of this technology, the fuel cell system may include a cooling channel through which cooling water circulates, a fuel cell stack provided on the cooling channel, and a first auxiliary device provided on the cooling channel and including metal parts that come into contact with the cooling water. The cooling channel may include a stack channel in which the fuel cell stack is arranged and a first channel in which the first auxiliary device is arranged. Part of the first channel may consist of a first metal pipe and a second metal pipe. The first auxiliary device may be arranged in the first channel between the first metal pipe and the second metal pipe. The first metal pipe and the second metal pipe may be configured to be grounded.

[0007] In the above configuration, the first and second metal tubes are arranged in a cooling channel located between the fuel cell stack and the first auxiliary equipment. Since the first and second metal tubes are configured to be grounded, the first auxiliary equipment can be indirectly grounded via the cooling water. Therefore, it is possible to avoid or suppress the static electricity buildup of the first auxiliary equipment, which is located in the same cooling channel as the fuel cell stack.

[0008] In a second embodiment, the fuel cell system in the first embodiment may further include a second auxiliary component provided on the cooling channel and including a metal component that comes into contact with the cooling water. The cooling channel may further include a second channel on which the second auxiliary component is located. The first metal tube may be a metal joint component that connects one end of the stack channel, one end of the first channel, and one end of the second channel to each other.

[0009] In the second flow path, it is desirable to have a metal pipe configured to be grounded on one end of the second flow path, beyond the second auxiliary equipment. With the above configuration, the number of metal pipes can be reduced compared to a configuration in which metal pipes are provided both on one end of the second flow path beyond the second auxiliary equipment and on one end of the first flow path beyond the first auxiliary equipment.

[0010] In a third embodiment, the fuel cell system may further include a third auxiliary component provided on the second flow path and having a metal component that comes into contact with the cooling water. The third auxiliary component may be configured to be grounded. The second auxiliary component may be located in the second flow path between the third auxiliary component and the first metal pipe.

[0011] In the above configuration, the first metal pipe and the third auxiliary equipment are arranged in a cooling channel located between the fuel cell stack and the second auxiliary equipment. Since the first metal pipe and the third auxiliary equipment are configured to be grounded, the second auxiliary equipment can be indirectly grounded via the cooling water. This prevents or suppresses the charging of the second auxiliary equipment, which is located in the same cooling channel as the fuel cell stack. For this reason, it is not necessary to provide a metal pipe on the other end of the second channel beyond the second auxiliary equipment. Consequently, the number of metal pipes can be reduced.

[0012] In a fourth embodiment, in the second embodiment, the second metal tube may be a metal joint component that connects the other end of the stacked flow path, the other end of the first flow path, and the other end of the second flow path to each other.

[0013] With the above configuration, the number of metal pipes can be reduced compared to a configuration in which metal pipes are provided both on the other end of the second auxiliary device in the second flow path and on the other end of the first auxiliary device in the first flow path.

[0014] In the fifth embodiment, in any one of the first to fourth embodiments described above, the first auxiliary device may be an intercooler, a radiator, or other heat exchanger. [Brief explanation of the drawing]

[0015] [Figure 1] This figure schematically shows the configuration of the fuel cell system 2 according to the first embodiment. [Figure 2] This figure schematically shows the configuration of the fuel cell system 202 according to the second embodiment. [Figure 3]This figure schematically shows the configuration of the fuel cell system 302 according to the third embodiment. [Figure 4] This figure schematically shows the configuration of the fuel cell system 402 according to the fourth embodiment. [Modes for carrying out the invention]

[0016] (First embodiment) Referring to Figure 1, the fuel cell system 2 of this embodiment will be described. Hereafter, "fuel cell" will be abbreviated as "FC". For example, FC system 2 is installed in a fuel cell vehicle.

[0017] The FC system 2 comprises a cooling passage 10 through which coolant circulates, an FC stack 12, a three-way valve 14, a radiator 16, a pump 18, and an intercooler 20.

[0018] The FC stack 12, three-way valve 14, radiator 16, pump 18, and intercooler 20 are installed on the cooling passage 10. The radiator 16, pump 18, and intercooler 20 include metal parts that come into contact with the coolant. The three-way valve 14 is made of resin. That is, the three-way valve 14 does not include any metal parts that come into contact with the coolant. In a modified version, the three-way valve 14 may include metal parts that come into contact with the coolant.

[0019] The FC stack 12 is equipped with multiple fuel cell cells. Each fuel cell generates electricity by chemically reacting hydrogen and oxygen. In other words, the FC stack 12 generates electricity by converting the chemical energy of hydrogen and oxygen into electrical energy. The radiator 16 cools the coolant through heat exchange with the outside air. The intercooler 20 is supplied with coolant as well as compressed air supplied from the air compressor. The intercooler 20 cools the compressed air through heat exchange with the coolant.

[0020] The cooling flow path 10 includes a stack flow path 30, a first flow path 32, a second flow path 34, and a first bypass flow path 36. The cooling flow path 10 is composed of a plurality of insulating tubes 38 and a plurality of metal tubes. In FIGS. 1 to 4, the insulating tubes 38 are shown by thin lines and the metal tubes are shown by thick lines. The metal tube is a joint component that connects two or more insulating tubes 38. The insulating tube 38 is made of an insulating material such as synthetic resin. The metal tube is made of a metal material such as steel, stainless steel, or aluminum.

[0021] The stack flow path 30 is provided with an FC stack 12. The stack flow path 30 is composed of a plurality of insulating tubes 38.

[0022] The stack flow path 30 and the first flow path 32 are connected in parallel with each other. The first flow path 32 is provided with an intercooler 20. The first flow path 32 is composed of a plurality of insulating tubes 38, a first metal tube 40, and a second metal tube 42. That is, a part of the first flow path 32 is composed of the first metal tube 40 and the second metal tube 42. The second metal tube 42 is provided upstream of the first metal tube 40. The first metal tube 40 and the second metal tube 42 connect two insulating tubes 38 that constitute the first flow path 32. The intercooler 20 is disposed between the first metal tube 40 and the second metal tube 42. The first metal tube 40 and the second metal tube 42 are configured to be grounded. Specifically, the first metal tube 40 and the second metal tube 42 are electrically connected to the grounds 40A and 42A, respectively. As an example, ground wires are connected to the first metal tube 40 and the second metal tube 42 using nuts or the like.

[0023] The second flow path 34 is equipped with a three-way valve 14, a radiator 16, and a pump 18. The radiator 16 is located downstream of the three-way valve 14. The pump 18 is located downstream of the radiator 16. The upstream end of the second flow path 34 is connected to the downstream end of the stack flow path 30 and the downstream end of the first flow path 32. The downstream end of the second flow path 34 is connected to the upstream end of the stack flow path 30 and the upstream end of the first flow path 32. The second flow path 34 is composed of a plurality of insulating tubes 38 and a third metal tube 44. That is, a portion of the second flow path 34 is composed of the third metal tube 44. The third metal tube 44 is located upstream of the three-way valve 14. The third metal tube 44 and the pump 18 are configured to be grounded. Specifically, the third metal tube 44 and the pump 18 are electrically connected to earths 44A and 18A, respectively.

[0024] The upstream end of the first bypass channel 36 is connected to the three-way valve 14. The downstream end of the first bypass channel 36 is connected to the second channel 34 between the radiator 16 and the pump 18. The first bypass channel 36 is made of an insulating pipe 38. The three-way valve 14 is switchable between a first communication state in which the second channel 34 upstream of the three-way valve 14 and the first bypass channel 36 are in communication, and a second communication state in which the second channel 34 upstream of the three-way valve 14 and the second channel 34 downstream of the three-way valve 14 are in communication.

[0025] The effects of the first metal pipe 40, the second metal pipe 42, and the third metal pipe 44 will be explained. In the FC system 2, auxiliary equipment such as the radiator 16, pump 18, and intercooler 20, which are located in the same cooling passage 10 as the FC stack 12, may become electrically charged via the coolant.

[0026] In the FC system 2 of this embodiment, a first metal pipe 40 is provided between the inlet of the FC stack 12 and the inlet of the intercooler 20, and a second metal pipe 42 is provided between the outlet of the FC stack 12 and the outlet of the intercooler 20. The first metal pipe 40 and the second metal pipe 42 are configured to be grounded. As a result, the intercooler 20 is indirectly grounded via the cooling water. Consequently, the intercooler 20 does not become charged.

[0027] Furthermore, the pump 18 is directly grounded. Therefore, the pump 18 does not become charged.

[0028] Furthermore, in FC system 2, a third metal pipe 44 is provided between the outlet of the FC stack 12 and the inlet of the radiator 16, and a pump 18 is provided between the inlet of the FC stack 12 and the outlet of the radiator 16. The third metal pipe 44 and the pump 18 are configured to be grounded. As a result, the radiator 16 is indirectly grounded via the coolant. Consequently, the radiator 16 does not become charged.

[0029] As described above, the FC system 2 comprises a cooling channel 10 through which cooling water circulates, an FC stack 12 provided on the cooling channel 10, and an intercooler 20 (an example of the "first auxiliary equipment") provided on the cooling channel 10 and including metal parts that come into contact with the cooling water. The cooling channel 10 includes a stack channel 30 in which the FC stack 12 is located, and a first channel 32 in which the intercooler 20 is located. Part of the first channel 32 is composed of a first metal pipe 40 and a second metal pipe 42. The intercooler 20 is located in the first channel 32 between the first metal pipe 40 and the second metal pipe 42. The first metal pipe 40 and the second metal pipe 42 are configured to be grounded.

[0030] In the above configuration, the first metal pipe 40 and the second metal pipe 42 are arranged in the cooling channel 10 located between the FC stack 12 and the intercooler 20. Since the first metal pipe 40 and the second metal pipe 42 are configured to be grounded, the intercooler 20 can be indirectly grounded via the cooling water. Therefore, the intercooler 20, which is located in the same cooling channel 10 as the FC stack 12, can avoid or suppress static electricity buildup.

[0031] (Second example) Referring to Figure 2, the FC system 202 according to the second embodiment will be described. In the second embodiment, the configuration of the cooling channel 210 differs from the configuration of the cooling channel 10 in the first embodiment. In the following, components common to both embodiments are denoted by the same reference numerals and their descriptions are omitted.

[0032] As shown in Figure 2, the cooling channel 210 is composed of a plurality of insulating tubes 38 and a plurality of metal tubes. The plurality of metal tubes include a first metal tube 240 and a second metal tube 42. The first metal tube 240 is a three-way joint that connects the downstream end of the stack channel 230, the downstream end of the first channel 232, and the upstream end of the second channel 234 to each other. That is, the first metal tube 240 connects three insulating tubes 38. The stack channel 230 is composed of the insulating tubes 38 and the first metal tube 240. The first channel 232 is composed of the insulating tubes 38, the first metal tube 240, and the second metal tube 42. Furthermore, the second channel 234 is composed of the insulating tubes 38 and the first metal tube 240.

[0033] As described above, the FC system 2 includes a radiator 16 (an example of a "second auxiliary device") which is located on the cooling passage 10 and includes metal parts that come into contact with the cooling water. The cooling passage 10 includes a second passage 234 in which the radiator 16 is located. The first metal pipe 240 is a metal joint component that connects the downstream end of the stack passage 230 (an example of "one end of the stack passage"), the downstream end of the first passage 232 (an example of "one end of the first passage"), and the upstream end of the second passage 234 (an example of "one end of the second passage") to each other.

[0034] With the above configuration, the number of metal pipes can be reduced compared to a configuration in which metal pipes are provided both upstream of the radiator 16 in the second flow path 234 and downstream of the intercooler 20 in the first flow path 232.

[0035] Furthermore, the FC system 202 is provided on the second flow path 234 and further includes a pump 18 (an example of a "third auxiliary device") having metal parts that come into contact with the cooling water. The pump 18 is configured to be grounded. The radiator 16 is located in the second flow path 234 between the pump 18 and the first metal pipe 240.

[0036] According to the above configuration, the first metal pipe 240 and the pump 18 are arranged in the cooling passage 210 located between the FC stack 12 and the radiator 16. Since the first metal pipe 240 and the pump 18 are configured to be grounded, the radiator 16 can be indirectly grounded via the cooling water. This prevents or suppresses the charging of the radiator 16, which is located in the same cooling passage 210 as the FC stack 12. For this reason, it is not necessary to provide a metal pipe downstream of the radiator 16 in the second passage 234. Consequently, the number of metal pipes can be reduced.

[0037] (Third embodiment) Referring to Figure 3, the FC system 302 according to the third embodiment will be described. In the third embodiment, the configuration of the cooling channel 310 differs from the configuration of the cooling channel 10 in the first embodiment. Also, in the third embodiment, the pump 18 is not configured to be grounded.

[0038] As shown in Figure 3, the cooling channel 310 is composed of a plurality of insulating tubes 38 and a plurality of metal tubes. The plurality of metal tubes include a first metal tube 340 and a second metal tube 342. The first metal tube 340 is a three-way joint that connects the downstream end of the stack channel 330, the downstream end of the first channel 332, and the upstream end of the second channel 334 to each other. The second metal tube 342 is a three-way joint that connects the upstream end of the stack channel 330, the upstream end of the first channel 332, and the downstream end of the second channel 334 to each other. In other words, the first metal tube 340 and the second metal tube 342 connect three insulating tubes 38. The stack channel 330, the first channel 332, and the second channel 334 are composed of a plurality of insulating tubes 38, the first metal tube 340, and the second metal tube 342. The first metal pipe 340 and the second metal pipe 342 are electrically connected to grounds 340A and 342A, respectively.

[0039] As described above, the second metal pipe 342 may be a metal joint component that connects the downstream end of the stacked channel 330 (an example of the "other end of the stacked channel"), the downstream end of the first channel 332 (an example of the "other end of the first channel"), and the upstream end of the second channel 334 (an example of the "other end of the second channel") to each other.

[0040] With the above configuration, the number of metal pipes can be reduced compared to a configuration in which metal pipes are provided both downstream of the radiator 16 in the second flow path 334 and upstream of the intercooler 20 in the first flow path 332.

[0041] (Fourth embodiment) Referring to Figure 4, the FC system 402 according to the fourth embodiment will be described. In the fourth embodiment, the configuration of the cooling channel 410 differs from the configuration of the cooling channel 10 in the first embodiment. Furthermore, the FC system 402 of the fourth embodiment further includes an ion exchanger 422. The ion exchanger 422 removes ions from the cooling water.

[0042] As shown in Figure 4, the cooling channel 410 includes a stack channel 30, a first channel 32, a second channel 34, a first bypass channel 36, and a second bypass channel 439.

[0043] The second bypass channel 439 bypasses the second channel 34. The upstream end of the second bypass channel 439 is connected to the second channel 34 between the pump 18 and the connection point between the downstream end of the first bypass channel 36 and the second channel 34. The downstream end of the second bypass channel 439 is connected to the second channel 34 between the pump 18 and the connection point between the stack channel 30, the first channel 32, and the second channel 34. An ion exchanger 422 is provided in the second bypass channel 439. The second bypass channel 439 is composed of a plurality of insulating tubes 38, a third metal tube 444, and a fourth metal tube 446. The fourth metal tube 446 is provided upstream of the third metal tube 444. The third metal tube 444 and the fourth metal tube 446 connect the two insulating tubes 38 that constitute the second bypass channel 439. The ion exchanger 422 is located between the third metal tube 444 and the fourth metal tube 446. The third metal pipe 444 and the fourth metal pipe 446 are configured to be grounded. Specifically, the third metal pipe 444 and the fourth metal pipe 446 are electrically connected to earths 444A and 446A, respectively.

[0044] The specific examples of the technology disclosed in this specification have been described in detail above, but these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes to the specific examples described above.

[0045] (First Modification) In the first to third embodiments, an ion exchanger may be provided in the first bypass channel 36.

[0046] (Second Modification) In the first and second embodiments, the pump 18 does not necessarily have to be configured to be grounded. In this modification, it is preferable that a grounded metal pipe is provided downstream of the pump 18 in the second flow paths 34 and 234.

[0047] (Third Modification) In the first and second embodiments, the intercooler 20 is configured to be grounded, and the pump 18 is not necessarily configured to be grounded. In this modification, the FC systems 2 and 202 do not need to have the first metal pipe 40 and the second metal pipe 42. In this modification, it is preferable that a grounded metal pipe is provided downstream of the pump 18 in the second flow paths 34 and 234. In this modification, the radiator 16 and pump 18 are examples of the "first auxiliary equipment," and the third metal pipe 44 and the metal pipe provided downstream of the pump 18 in the second flow paths 34 and 234 are examples of the "first metal pipe" and the "second metal pipe," respectively.

[0048] (Fourth Modification) In the fourth embodiment, the intercooler 20 and the radiator 16 may be configured to be grounded. In this modification, the FC system 402 does not need to have the first metal tube 40, the second metal tube 42, and the third metal tube 44. In this modification, the ion exchanger 422 is an example of the "first auxiliary equipment," and the third metal tube 444 and the fourth metal tube 446 are examples of the "first metal tube" and the "second metal tube," respectively.

[0049] The technical elements described herein or in the drawings demonstrate technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated herein or in the drawings can achieve multiple objectives simultaneously, and achieving even one of these objectives constitutes technical usefulness in itself. [Explanation of Symbols]

[0050] 2: Fuel cell system, 10: Cooling channel, 12: FC stack, 14: Three-way valve, 16: Radiator, 18: Pump, 18A: Ground, 20: Intercooler, 30: Stack channel, 32: First channel, 34: Second channel, 36: First bypass channel, 38: Insulating tube, 40: First metal tube, 40A: Ground, 42: Second metal tube, 42A: Ground, 44: Third metal tube, 44A: Ground, 202: Fuel cell system, 210: Cooling channel, 230: Stack channel, 232: First channel, 234: Second channel, 240: First metal tube, 302: Fuel cell system, 310: Cooling channel, 330: Stack channel, 332: First channel, 334: Second channel, 340: First metal tube, 340A: Ground, 342: Second metal tube, 342A: Ground, 402: Fuel cell system, 410: Cooling channel, 422: Ion exchanger, 439: Second bypass channel, 444: Third metal tube, 444A: Ground, 446: Fourth metal tube, 446A: Ground

Claims

1. A cooling channel through which cooling water circulates, A fuel cell stack provided on the aforementioned cooling channel, The system includes a first auxiliary device provided on the cooling channel and containing a metal part that comes into contact with the cooling water, The cooling channel includes a stack channel in which the fuel cell stack is arranged and a first channel in which the first auxiliary equipment is arranged. A portion of the first flow path is composed of a first metal tube and a second metal tube. The first auxiliary device is positioned between the first metal pipe and the second metal pipe in the first flow path. The first metal pipe and the second metal pipe are configured to be grounded. Fuel cell system.

2. The system further comprises a second auxiliary device which is provided on the cooling channel and includes a metal component that comes into contact with the cooling water, The cooling channel further includes a second channel in which the second auxiliary device is located. The fuel cell system according to claim 1, wherein the first metal tube is a metal joint component that connects one end of the stack flow path, one end of the first flow path, and one end of the second flow path to each other.

3. The system further comprises a third auxiliary device provided on the second flow path and having a metal component that comes into contact with the cooling water, The third auxiliary device is configured to be grounded, The fuel cell system according to claim 2, wherein the second auxiliary device is disposed in the second flow path between the third auxiliary device and the first metal pipe.

4. The fuel cell system according to claim 2, wherein the second metal tube is a metal joint component that connects the other end of the stack flow path, the other end of the first flow path, and the other end of the second flow path to each other.

5. The fuel cell system according to any one of claims 1 to 4, wherein the first auxiliary device is an intercooler, a radiator, or other heat exchanger.

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