Fuel cell system

Abstract

A fuel cell system is provided with: a fuel cell; an oxidizing gas supply line for conveying an oxidizing gas to the fuel cell; a compressor configured so as to be provided in the oxidizing gas supply line and to compress the oxidizing gas; a cold / hot medium supply line for supplying a cold / hot medium for cooling the fuel cell to the fuel cell; a cold / hot medium pump provided in the cold / hot medium supply line and configured to increase the pressure of the cold / hot medium; and an oxidizing gas cooler configured so as to exchange heat between a cold / hot medium that flows through a cold / hot medium supply line and an oxidizing gas that flows downstream of the compressor in the oxidizing gas supply line and that is compressed by the compressor.

Description

Technical Field

[0001] The present disclosure relates to a fuel cell system configured to supply an oxidizing gas compressed by a compressor to a fuel cell.

[0002] This application claims priority based on Tokugan Application No. 2022-134487 filed with the Japan Patent Office on August 25, 2022, the contents of which are cited herein. Background Art

[0003] A fuel cell vehicle (FCEV) is configured to use the electric energy generated by the chemical reaction between the fuel gas (hydrogen) and the oxidizing gas (oxygen) in the fuel cell to rotate the driving motor for driving. The hydrogen supplied to the fuel cell is stored in a hydrogen tank mounted on the fuel cell vehicle. The oxygen supplied to the fuel cell uses oxygen in the air. In order to be able to supply a large amount of air to the fuel cell or to maintain the pressure inside the fuel cell, an electric compressor is sometimes provided in the oxygen supply system for supplying oxygen to the fuel cell.

[0004] The air compressed by the electric compressor has a high temperature and needs to be cooled to a temperature suitable for the fuel cell before being supplied to the fuel cell. Patent document 1 discloses supplying the air compressed by the electric compressor to the fuel cell after cooling using an air-cooled heat exchanger or a water-cooled heat exchanger.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: (Japanese) Patent Publication No. 2014-120336

[0008] Patent Document 2: (Japanese) Patent Publication No. 2002-56865 Summary of the invention

[0009] Technical problem to be solved by the invention

[0010] The water-cooled heat exchangers described in Patent Documents 1 and 2 require dedicated pipes and pumps for supplying cooling water to the heat exchangers, which may complicate the structure of a fuel cell system including a fuel cell or an electric compressor.

[0011] In view of the above circumstances, an object of at least one embodiment of the present disclosure is to provide a fuel cell system capable of achieving simplification of its configuration.

[0012] Technical solutions for solving technical problems

[0013] A fuel cell system according to an embodiment of the present disclosure comprises: a fuel cell; an oxidizing gas supply pipeline for conveying oxidizing gas to the fuel cell; a compressor, which is arranged on the oxidizing gas supply pipeline and compresses the oxidizing gas; a cold and hot medium supply pipeline, which is arranged on the cold and hot medium supply pipeline and supplies a cold and hot medium for cooling the fuel cell to the fuel cell; a cold and hot medium pump, which is arranged on the cold and hot medium supply pipeline and increases the pressure of the cold and hot medium; and an oxidizing gas cooler, which is arranged on the cold and hot medium supply pipeline and performs heat exchange between the cold and hot medium and the oxidizing gas, wherein the cold and hot medium flows in the cold and hot medium supply pipeline, and the oxidizing gas flows in the oxidizing gas supply pipeline at a position downstream of the compressor and is compressed by the compressor.

[0014] Effects of the Invention

[0015] According to at least one embodiment of the present disclosure, a fuel cell system is provided that realizes a simplified configuration thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of a fuel cell system according to one embodiment.

[0017] Figure 2 This is a schematic diagram of a fuel cell system according to one embodiment.

[0018] Figure 3 This is a schematic diagram of a fuel cell system according to one embodiment.

[0019] Figure 4 This is a schematic diagram of a fuel cell system according to one embodiment.

[0020] Figure 5 This is a schematic diagram of a fuel cell system according to one embodiment.

[0021] Figure 6 This is a schematic diagram of a fuel cell system according to one embodiment.

[0022] Figure 7 This is a schematic diagram of a fuel cell system according to one embodiment.

[0023] Figure 8 This is a schematic diagram of a fuel cell system according to one embodiment.

[0024] Fig. 9 This is a schematic diagram of a fuel cell system according to one embodiment.

[0025] Fig.10 This is a schematic diagram of a fuel cell system according to one embodiment.

[0026] Fig.11 This is a schematic diagram of a fuel cell system according to one embodiment.

[0027] Fig.12 This is a schematic diagram of a fuel cell system according to one embodiment. DETAILED DESCRIPTION

[0028] Hereinafter, several embodiments of the present disclosure will be described with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present disclosure, but are merely simple illustrative examples.

[0029] (Fuel Cell System)

[0030] Figures 1 to 12 They are schematic diagrams of a fuel cell system 1 according to an embodiment of the present disclosure. It should be noted that: Figures 1 to 12 The temperature shown in is an example of the temperature of the fluid flowing in each flow path. Figures 1 to 12 As shown, the fuel cell system 1 of several embodiments includes a fuel cell (FC: FuelCell) 2 including at least an air electrode 21 and a fuel electrode 22, an oxidizing gas supply line 3 for supplying oxidizing gas to the air electrode 21 of the fuel cell 2, and a fuel gas supply line 4 for supplying fuel gas to the fuel electrode 22 of the fuel cell 2. The fuel cell system 1 supplies oxidizing gas or fuel gas to the fuel cell 2, and generates electricity using the fuel cell 2. The fuel cell system 1 can also be mounted on an electric vehicle (not shown) that is configured to be able to travel using the electricity generated by the fuel cell 2.

[0031] (Fuel Cell)

[0032] The fuel cell 2 supplies (supplements) an oxidizing gas (oxygen in the air in the example shown in the figure) that becomes a positive electrode active material and a fuel gas (hydrogen in the example shown in the figure) that becomes a negative electrode active material at room temperature or high temperature. The fuel cell 2 is configured to generate electricity through an electrochemical reaction between the supplied oxidizing gas and the fuel gas.

[0033] In the illustrated embodiment, the oxidizing gas supplied to the fuel cell 2 is composed of oxygen in the air, and the fuel gas supplied to the fuel cell 2 is composed of hydrogen. Figures 1 to 12 As shown, the fuel cell 2 has at least one power generation unit 20, which includes an air electrode 21 as an electron receiving side electrode (cathode), a fuel electrode 22 as an electron emitting side electrode (anode), and an electrolyte membrane 23 sandwiched between the air electrode 21 and the fuel electrode 22 in a manner of separating the air electrode 21 and the fuel electrode 22. It should be noted that the fuel cell 2 can also be constructed by stacking a plurality of power generation units 20 and a separator sandwiched between each of the plurality of power generation units 20. In the illustrated embodiment, the electrolyte membrane 23 is composed of a solid polymer electrolyte membrane.

[0034] The fuel cell 2 supplies oxygen-containing air to the catalyst layer on the air electrode 21 side of each of the plurality of power generation units 20 via the oxidizing gas supply line 3. In addition, the fuel cell 2 supplies hydrogen gas to the catalyst layer on the fuel electrode 22 side of each of the plurality of power generation units 20 via the fuel gas supply line 4. The fuel cell 2 supplies oxygen-containing air to the air electrode 21 and hydrogen gas to the fuel electrode 22, thereby generating the chemical reaction shown below, and thus being able to extract electric energy as an electromotive force generated between the electrodes (between the air electrode 21 and the fuel electrode 22).

[0035] Fuel electrode 22 (anode): H2→2H++2e-

[0036] Air electrode 21 (cathode): 1 / 2O2+2H++2e-→H2O

[0037] (Oxidizing gas supply line)

[0038] like Figures 1 to 12 As shown, the fuel cell system 1 further includes a compressor (compressor) 31, which is configured to be provided in the oxidizing gas supply line 3 and compress the oxidizing gas. The oxidizing gas supply line 3 includes an oxidizing gas introduction flow path (pipeline) 30 for guiding the oxygen-containing air (oxidizing gas) compressed by the compressor 31 to the air electrode 21 of the fuel cell 2. One end (upstream end) of the oxidizing gas introduction flow path 30 is connected to the compressor 31, and the other end (downstream end) thereof is connected to the air electrode 21 of the fuel cell 2.

[0039] By utilizing the suction force generated by rotating the compressor 31, the oxygen-containing air is guided to the compressor 31 from a position on the upstream side of the compressor 31 of the oxidizing gas supply line 3, and is compressed by the compressor 31. The oxygen-containing air compressed by the compressor 31 is supplied to the air electrode 21 (the catalyst layer on the air electrode 21 side) of the fuel cell 2 via the oxidizing gas introduction flow path 30.

[0040] In the illustrated embodiment, the compressor 31 includes an electric compressor 31A, which is configured to compress oxygen by being driven by an electric motor (electric motor) 32. The fuel cell system 1 further includes: the electric motor 32, which generates a rotational force to rotate the compressor 31; and a rotating shaft 33, which is mechanically connected to the compressor 31 and the electric motor 32, and transmits the above-mentioned rotational force generated by the electric motor 32 to the compressor 31.

[0041] (Fuel gas supply line)

[0042] like Figures 1 to 12As shown, the fuel cell system 1 further includes a fuel gas storage device (e.g., a hydrogen storage tank) 41 configured to store fuel gas (hydrogen gas). The fuel gas supply line 4 includes a flow path (pipeline) for supplying fuel gas from the fuel gas storage device 41 to the fuel electrode 22 (the catalyst layer on the fuel electrode 22 side) of the fuel cell 2. One end (upstream end) of the fuel gas supply line 4 is connected to the fuel gas storage device 41, and the other end (downstream end) thereof is connected to the fuel electrode 22 of the fuel cell 2. The fuel gas stored in the fuel gas storage device 41 is supplied to the fuel electrode 22 (the catalyst layer on the fuel electrode 22 side) of the fuel cell 2 via the fuel gas supply line 4.

[0043] like Figure 1 to Figure 7 , Fig.11 and Fig.12 As shown, the fuel cell system 1 may further include a first fuel gas flow rate regulating valve 42, which is configured to be provided in the fuel gas supply line 4 and capable of regulating the flow rate of the fuel gas passing through the fuel gas supply line 4. By adjusting the opening of the first fuel gas flow rate regulating valve 42, the flow rate of the fuel gas flowing in the fuel gas supply line 4 at a position downstream of the first fuel gas flow rate regulating valve 42 is adjusted.

[0044] When the first fuel gas flow rate regulating valve 42 is fully closed, the pressure on the upstream side of the fuel gas supply line 4 (the side where the fuel gas storage device 41 is located) of the first fuel gas flow rate regulating valve 42 is higher than the pressure on the downstream side of the fuel gas supply line 4 (the side where the fuel electrode 22 of the fuel cell 2 is located) of the first fuel gas flow rate regulating valve 42. Due to the pressure difference between the upstream side of the first fuel gas flow rate regulating valve 42 and the downstream side of the first fuel gas flow rate regulating valve 42 of the fuel gas supply line 4, when the first fuel gas flow rate regulating valve 42 is opened, the fuel gas flows from the upstream side to the downstream side of the fuel gas supply line 4.

[0045] (Fuel gas exhaust line)

[0046] like Figures 1 to 12 As shown, the fuel cell system 1 may also include a fuel gas exhaust line 7 for conveying the remaining fuel gas exhausted from the fuel electrode 22 of the fuel cell 2. One end (upstream end) of the fuel gas exhaust line 7 is connected to the fuel electrode 22 of the fuel cell 2. The fuel gas exhausted from the fuel cell 2 to the fuel gas exhaust line 7 is exhausted to the outside of the fuel cell system 1 via the fuel gas exhaust line 7.

[0047] like Figures 1 to 12As shown, the fuel cell system 1 may further include a second fuel gas flow rate regulating valve 71, which is configured to be provided in the fuel gas discharge line 7 and capable of regulating the flow rate of the fuel gas passing through the fuel gas discharge line 7. By adjusting the opening of the second fuel gas flow rate regulating valve 71, the flow rate of the fuel gas flowing in the fuel gas discharge line 7 at a position downstream of the second fuel gas flow rate regulating valve 71 is adjusted.

[0048] When the second fuel gas flow rate regulating valve 71 is fully closed, the pressure on the upstream side of the fuel gas discharge line 7 (the side where the fuel electrode 22 is located) of the second fuel gas flow rate regulating valve 71 is higher than the pressure on the downstream side of the fuel gas discharge line 7 of the second fuel gas flow rate regulating valve 71. Due to the pressure difference between the upstream side of the fuel gas discharge line 7 of the second fuel gas flow rate regulating valve 71 and the downstream side of the second fuel gas flow rate regulating valve 71, when the second fuel gas flow rate regulating valve 71 is opened, the fuel gas flows from the upstream side of the fuel gas discharge line 7 to the downstream side.

[0049] It should be noted that the first fuel gas flow regulating valve 42 and the second fuel gas flow regulating valve 71 can be either on-off valves capable of adjusting the opening to fully closed and fully open, or opening regulating valves capable of adjusting the opening to fully closed, fully open and at least one intermediate opening therebetween.

[0050] (Exhaust line)

[0051] like Figures 1 to 12 As shown, the fuel cell system 1 further includes an exhaust line 5 for conveying exhaust gas discharged from the air electrode 21 of the fuel cell 2. The exhaust gas discharged from the air electrode 21 of the fuel cell 2 includes exhaust gas (water vapor) generated by the electrochemical reaction of the fuel gas (hydrogen) and the oxidizing gas (oxygen) in the fuel cell 2. One end (upstream end) of the exhaust line 5 is connected to the air electrode 21 of the fuel cell 2. The exhaust gas discharged from the fuel cell 2 to the exhaust line 5 is discharged to the outside of the fuel cell system 1 via the exhaust line 5.

[0052] like Figures 1 to 12 As shown, the fuel cell system 1 further includes a turbine (expander) 51, which is arranged in the exhaust line 5 and driven by the exhaust gas. The exhaust gas discharged from the air electrode 21 of the fuel cell 2 is guided to the turbine 51 via the exhaust line 5. The turbine 51 is configured to rotate by the energy (expansion energy) of the exhaust gas guided to the turbine 51. The turbine 51 is configured to expand the exhaust gas guided to the turbine 51.

[0053] In the illustrated embodiment, the turbine 51 is mechanically connected to the compressor 31 via the rotating shaft 33. The compressor 31 and the turbine 51 are coaxially arranged with each other via the rotating shaft 33 which is the output shaft of the electric motor 32 for driving the compressor 31, and are respectively connected to the rotating shaft 33. The electric motor 32 is supplied with electric current from a power source (generator, etc.) not shown in the figure, and is driven by the electric current supplied from the power source to drive (rotate) the rotating shaft 33, the compressor 31 and the turbine 51. In the turbine 51, a part of the expansion energy generated when the exhaust gas expands is recovered, and the drive (rotation) of the compressor 31 is assisted by the recovered expansion energy. It should be noted that the electric motor 32 can also be driven by supplying electricity generated by the fuel cell 2.

[0054] (Cold and hot medium supply pipelines)

[0055] like Figures 1 to 12 As shown, the fuel cell system 1 further comprises: a cold and hot medium supply pipeline 6, which is used to supply the cold and hot medium for cooling the fuel cell 2 to the fuel cell 2; and a cold and hot medium pump 61, which is configured to be provided on the cold and hot medium supply pipeline 6 and to increase the pressure of the cold and hot medium. One end (upstream end) of the cold and hot medium supply pipeline 6 is connected to the cold and hot medium pump 61, and the other end (downstream end) thereof includes at least a cold and hot medium supply flow path (pipeline) connected to the fuel cell 2.

[0056] In the fuel cell 2, it is configured to perform heat exchange between the gas (oxidizing gas or fuel gas) inside the fuel cell 2 and a cold and hot medium (coolant such as water) which is guided to the fuel cell 2 and is lower in temperature than the gas inside the fuel cell 2. Through the heat exchange in the fuel cell 2, the gas inside the fuel cell 2 is cooled by the cold and hot medium guided to the fuel cell 2. The cold and hot medium may also flow in a flow path formed inside the partition and perform heat exchange with the gas inside the fuel cell 2 in the flow path. It should be noted that in the fuel cell 2, the gas inside the fuel cell 2 and the cold and hot medium are not mixed.

[0057] In the illustrated embodiment, the cold / hot medium supply line 6 includes a cold / hot medium circulation line 60A for circulating the cold / hot medium, that is, a cold / hot medium circulation line 60A provided with a cold / hot medium pump 61 and a fuel cell 2. The cold / hot medium is pressurized by the cold / hot medium pump 61 and circulates in the cold / hot medium circulation line 60A (cold / hot medium supply line 6).

[0058] The cold and hot medium pump 61 may also be configured to be connected to the drive shaft of the electric motor 62 and driven by the electric motor 62. The electric motor 62 is supplied with current from a power source (generator, etc.) not shown in the figure, and is driven by the current supplied from the power source to drive the cold and hot medium pump 61 (rotate the moving blades of the cold and hot medium pump 61). It should be noted that the electric motor 62 may also be driven by being supplied with electricity generated by the fuel cell 2.

[0059] (Oxidation Gas Cooler)

[0060] like Figures 1 to 12 As shown, the fuel cell system 1 of several embodiments further includes an oxidizing gas cooler 63, which is configured to perform heat exchange between a cold and hot medium and an oxidizing gas, wherein the cold and hot medium flows in the above-mentioned cold and hot medium supply pipeline 6, and the oxidizing gas flows in the above-mentioned oxidizing gas supply pipeline 3 at a position downstream of the compressor 31 and is compressed by the compressor 31.

[0061] The cold and hot medium pressurized by the cold and hot medium pump 61 is guided to the oxidizing gas cooler 63 via the cold and hot medium supply line 6. The cold and hot medium guided to the oxidizing gas cooler 63 is lower in temperature (e.g., about 50° C.) than the oxidizing gas guided to the oxidizing gas cooler 63. Therefore, the oxidizing gas is cooled and the cold and hot medium is heated by heat exchange in the oxidizing gas cooler 63. The oxidizing gas cooled in the oxidizing gas cooler 63 is guided to the air electrode 21 of the fuel cell 2.

[0062] According to the above structure, the oxidizing gas supplied to the fuel cell 2 can be cooled by heat exchange in the oxidizing gas cooler 63. Thus, the oxidizing gas compressed in the compressor 31 and reaching a relatively high temperature (e.g., about 200° C.) can be cooled to a temperature suitable for the chemical reaction in the fuel cell 2 (e.g., about 60° C.) before being supplied to the fuel cell 2. In the fuel cell system 1, since the cooling system of the fuel cell 2 such as the cooling medium supply pipeline 6 or the cooling medium pump 61 is used to supply the cooling medium to the oxidizing gas cooler 63, a dedicated pipeline and pump are not required, and the structure of the fuel cell system 1 can be simplified.

[0063] In some embodiments, such as Figures 1 to 12As shown, the cold and hot medium supply line 6 includes the cold and hot medium circulation line 60A and the bypass line 60B that bypasses the fuel cell 2. The bypass line 60B branches from the cold and hot medium circulation line 60A at a branching portion P1 on the upstream side of the fuel cell 2 and on the downstream side of the cold and hot medium pump 61 of the cold and hot medium circulation line 60A. The bypass line 60B merges with the cold and hot medium circulation line 60A at a confluence portion P2 on the downstream side of the fuel cell 2 and on the upstream side of the cold and hot medium pump 61 of the cold and hot medium circulation line 60A. The oxidizing gas cooler 63 is provided in the bypass line 60B. In this case, since the cold and hot medium that does not cool the other of the fuel cell 2 and the oxidizing gas cooler 63 is supplied to each of the fuel cell 2 and the oxidizing gas cooler 63, the fuel cell 2 and the oxidizing gas cooler 63 can be effectively cooled by the cold and hot medium. It should be noted that in other embodiments, the oxidizing gas cooler 63 may also be disposed upstream or downstream of the fuel cell 2 in the cold / hot medium circulation line 60A (cold / hot medium supply line 6 ).

[0064] like Figure 1 , Figure 2 , Figures 4 to 10 As shown, the fuel cell system 1 may further include a radiator (cooler) 64 for cooling the cold and hot medium flowing in the cold and hot medium supply line 6. In the illustrated embodiment, the radiator 64 is provided in the bypass line 60B, but may also be provided in the cold and hot medium circulation line 60A. The cold and hot medium whose temperature rises in the fuel cell 2 or the oxidizing gas cooler 63 is cooled in the radiator 64. Thus, the temperature of the cold and hot medium flowing in the cold and hot medium supply line 6 is maintained.

[0065] (First heat exchanger)

[0066] In some embodiments, such as Figure 1 As shown, the above-mentioned fuel cell system 1 also has a first heat exchanger 52, which is configured to perform heat exchange between exhaust gas and oxidizing gas, wherein the exhaust gas flows at a position on the exhaust pipeline 5 downstream of the turbine 51, and the oxidizing gas flows at a position on the oxidizing gas supply pipeline 3 downstream of the compressor 31.

[0067] The exhaust line 5 includes a first exhaust gas introduction flow path (pipe) 50A for guiding the exhaust gas expanded by the turbine 51 to the first heat exchanger 52. One end (upstream end) of the first exhaust gas introduction flow path 50A is connected to the turbine 51, and the other end (downstream end) thereof is connected to the first heat exchanger 52.

[0068] The exhaust gas expanded by the turbine 51 and having its temperature lowered is guided to the first heat exchanger 52 via the first exhaust gas introduction flow path 50A. The exhaust gas guided to the first heat exchanger 52 is lower in temperature (for example, about 10° C.) than the oxidizing gas guided to the first heat exchanger 52. Therefore, the oxidizing gas is cooled and the exhaust gas is heated by the heat exchange in the first heat exchanger 52. The oxidizing gas cooled in the first heat exchanger 52 and the oxidizing gas cooler 63 is guided to the air electrode 21 of the fuel cell 2.

[0069] exist Figure 1 In the illustrated embodiment, the first heat exchanger 52 is provided on the oxidizing gas supply line 3 at a position upstream of the oxidizing gas cooler 63. The oxidizing gas cooled in the first heat exchanger 52 is guided to the oxidizing gas cooler 63.

[0070] According to the above structure, the oxidant gas supplied to the fuel cell 2 can be cooled by heat exchange in the first heat exchanger 52. By utilizing the exhaust gas expanded in the turbine 51 and having a relatively low temperature (e.g., about 10° C.) in the cooling of the oxidant gas supplied to the fuel cell 2, the heat loss of the cooling system of the fuel cell 2 can be suppressed, and the structure of the fuel cell system 1 can be simplified. It should be noted that the fuel cell system 1 includes the first heat exchanger 52, but may be configured not to include at least one of the other heat exchangers and coolers such as the oxidant gas cooler 63.

[0071] (Fuel Cell Cooler)

[0072] In some embodiments, such as Figure 2 As shown, the fuel cell system 1 further includes a fuel cell cooler 53 configured to cool the fuel cell 2 using the exhaust gas flowing in the exhaust line 5 at a position downstream of the turbine 51 .

[0073] The exhaust line 5 includes a third exhaust gas introduction flow path (pipe) 50C for guiding the exhaust gas expanded by the turbine 51 to the fuel cell cooler 53. One end (upstream end) of the third exhaust gas introduction flow path 50C is connected to the turbine 51, and the other end (downstream end) thereof is connected to the fuel cell cooler 53. It should be noted that the first exhaust gas introduction flow path 50A and the third exhaust gas introduction flow path 50C may also serve as a flow path (pipe) from the end connected to the turbine 51 to the branch portion P4.

[0074] The exhaust gas that has been expanded and whose temperature has been reduced by the turbine 51 is guided to the fuel cell cooler 53 via the third exhaust gas flow path 50C. In the fuel cell cooler 53, it is configured to perform heat exchange between the gas (oxidizing gas, fuel gas) inside the fuel cell 2 and the exhaust gas that is lower in temperature than the gas inside the above-mentioned fuel cell 2 and is guided to the fuel cell cooler 53. Through the heat exchange in the fuel cell cooler 53, the gas inside the fuel cell 2 is cooled by the exhaust gas guided to the fuel cell cooler 53. The exhaust gas may also flow in a flow path formed inside the partition, and perform heat exchange with the gas inside the fuel cell 2 in the flow path. It should be noted that in the fuel cell cooler 53, the gas inside the fuel cell 2 and the exhaust gas inside the fuel cell cooler 53 are not mixed.

[0075] According to the above structure, the fuel cell 2 can be cooled in the fuel cell cooler 53. By utilizing the exhaust gas that has expanded in the turbine 51 and has a relatively low temperature (e.g., about 10° C.) in cooling the fuel cell 2, the heat loss of the cooling system of the fuel cell 2 can be suppressed, and the structure of the fuel cell system 1 can be simplified. It should be noted that the fuel cell system 1 includes the fuel cell cooler 53, but can also be configured not to include at least one of the other heat exchangers and coolers such as the oxidizing gas cooler 63.

[0076] (Second heat exchanger)

[0077] In some embodiments, such as Figure 3 As shown, the above-mentioned fuel cell system 1 also has a second heat exchanger 54, which is configured to perform heat exchange between exhaust gas and cold and hot media. The exhaust gas flows in the above-mentioned exhaust pipeline 5 at a position downstream of the turbine 51, and the cold and hot media flows in the cold and hot media supply pipeline 6.

[0078] The exhaust line 5 includes a fourth exhaust gas introduction flow path (pipe) 50D for guiding the exhaust gas expanded by the turbine 51 to the second heat exchanger 54. One end (upstream end) of the fourth exhaust gas introduction flow path 50D is connected to the turbine 51, and the other end (downstream end) thereof is connected to the second heat exchanger 54.

[0079] The second heat exchanger 54 is provided in the bypass line 60B (cold and hot medium supply line 6). The exhaust gas expanded by the turbine 51 and having its temperature lowered is guided to the second heat exchanger 54 via the fourth exhaust gas introduction flow path 50D. The exhaust gas guided to the second heat exchanger 54 is lower in temperature (for example, about 10° C.) than the cold and hot medium guided to the second heat exchanger 54. Therefore, through the heat exchange in the second heat exchanger 54, the cold and hot medium is cooled and the exhaust gas is heated.

[0080] According to the above structure, the cold and hot medium flowing in the cold and hot medium supply pipeline 6 can be cooled by heat exchange in the second heat exchanger 54. By using the exhaust gas that has expanded in the turbine 51 and has a relatively low temperature (about 10°C) in the cooling of the cooling medium, the cold and heat loss of the cooling system of the fuel cell 2 can be suppressed, and the structure of the fuel cell system 1 can be simplified. It should be noted that the fuel cell system 1 includes the second heat exchanger 54, but can also be configured without at least one of the other heat exchangers and coolers such as the oxidizing gas cooler 63.

[0081] (Third heat exchanger)

[0082] In some embodiments, such as Figure 4 As shown, the above-mentioned fuel cell system 1 also has a third heat exchanger 55, which is configured to perform heat exchange between exhaust gas and oxidizing gas, wherein the exhaust gas flows in the above-mentioned exhaust pipeline 5 at a position upstream of the turbine 51, and the oxidizing gas flows in the oxidizing gas supply pipeline 3 at a position downstream of the compressor 31.

[0083] The exhaust line 5 includes a fifth exhaust gas introduction flow path (pipe) 50E for guiding the exhaust gas discharged from the air electrode 21 of the fuel cell 2 to the turbine 51. One end (upstream end) of the fifth exhaust gas introduction flow path 50E is connected to the air electrode 21 of the fuel cell 2, and the other end (downstream end) thereof is connected to the turbine 51.

[0084] The exhaust gas before being introduced into the turbine 51 is guided to the third heat exchanger 55 via the fifth exhaust gas introduction flow path (pipe) 50E. The exhaust gas guided to the third heat exchanger 55 is lower in temperature (e.g., about 80° C.) than the oxidant gas guided to the third heat exchanger 55. Therefore, the oxidant gas is cooled and the exhaust gas is heated by the heat exchange in the third heat exchanger 55. The oxidant gas cooled in the third heat exchanger 55 and the oxidant gas cooler 63 is guided to the air electrode 21 of the fuel cell 2.

[0085] exist Figure 4 In the illustrated embodiment, the third heat exchanger 55 is provided on the upstream side of the oxidizing gas cooler 63 in the oxidizing gas supply line 3. The oxidizing gas cooled in the third heat exchanger 55 is guided to the oxidizing gas cooler 63.

[0086] According to the above structure, the oxidizing gas supplied to the fuel cell 2 can be cooled by heat exchange in the third heat exchanger 55. By utilizing the relatively low temperature (about 80° C.) exhaust gas before being introduced into the turbine 51 in cooling the oxidizing gas supplied to the fuel cell 2, the heat loss of the cooling system of the fuel cell 2 can be suppressed, and the structure of the fuel cell system 1 can be simplified.

[0087] According to the above structure, the exhaust gas before being introduced into the turbine 51 can be heated by heat exchange in the third heat exchanger 55. By increasing the temperature of the exhaust gas introduced into the turbine 51, the energy that can be recovered in the turbine 51 can be increased. In the case where the turbine 51 is connected to the compressor 31 via the rotating shaft 33, the amount of assistance provided by the turbine 51 to the drive (rotation) of the compressor 31 can be increased by increasing the energy that can be recovered in the turbine 51. As a result, the power required for the drive (rotation) of the compressor 31 (for example, the power consumption of the electric motor 32) can be reduced. It should be noted that the fuel cell system 1 has the third heat exchanger 55, but can also be configured to not have at least one of the other heat exchangers and coolers such as the oxidation gas cooler 63.

[0088] (Motor Cooler)

[0089] In some embodiments, Figure 1 to Figure 4 As shown, the compressor 31 includes an electric compressor 31A, which is driven by an electric motor 32 to compress the oxidizing gas. The fuel cell system 1 further includes a motor cooler 56, which is configured to cool the electric motor 32 using the exhaust gas flowing in the exhaust line 5 at a position downstream of the turbine 51.

[0090] The exhaust line 5 includes a second exhaust gas introduction flow path (pipe) 50B for guiding the exhaust gas expanded by the turbine 51 to the motor cooler 56. One end (upstream end) of the second exhaust gas introduction flow path 50B is connected to the turbine 51, and the other end (downstream end) thereof is connected to the motor cooler 56. Figure 1 and Figure 2 As shown in FIG. 1 , the first exhaust gas introduction flow path 50A and the second exhaust gas introduction flow path 50B may also be used as a flow path (pipe) from one end connected to the turbine 51 to the branch portion P3. Figure 3 As shown, the second exhaust gas introduction flow path 50B and the fourth exhaust gas introduction flow path 50D may also serve as a flow path (pipe) from one end connected to the turbine 51 to the branch portion P5.

[0091] The exhaust gas expanded by the turbine 51 and having its temperature lowered is guided to the motor cooler 56 via the second exhaust gas introduction flow path 50B. The motor cooler 56 is configured to perform heat exchange between the electric motor 32 and the exhaust gas guided to the motor cooler 56 and having a lower temperature than the electric motor 32. The electric motor 32 is cooled by the exhaust gas guided to the motor cooler 56 through the heat exchange in the motor cooler 56.

[0092] According to the above structure, the electric motor 32 can be cooled in the motor cooler 56. By utilizing the exhaust gas that has expanded in the turbine 51 and has a relatively low temperature (about 10° C.) to cool the electric motor 32, overheating of the electric motor 32 can be suppressed, and the structure of the fuel cell system 1 can be simplified. It should be noted that the fuel cell system 1 includes the motor cooler 56, but may be configured not to include at least one of the other heat exchangers and coolers such as the oxidizing gas cooler 63.

[0093] (Fourth Heat Exchanger)

[0094] In some embodiments, such as Figure 5 , Figure 6 , Figure 8 , Fig. 9 as well as Fig.11 As shown, the above-mentioned fuel cell system 1 also has a fourth heat exchanger 43, which is configured to perform heat exchange between fuel gas and oxidant gas, wherein the fuel gas flows in the above-mentioned fuel gas supply pipeline 4, and the oxidant gas flows in the oxidant gas supply pipeline 3 at a position upstream of the compressor 31.

[0095] The fuel gas guided to the fourth heat exchanger 43 is lower in temperature than the oxidizing gas guided to the fourth heat exchanger 43. Therefore, by heat exchange in the fourth heat exchanger 43, the oxidizing gas is cooled and the fuel gas is heated.

[0096] According to the above structure, the oxidizing gas before being introduced into the compressor 31 is cooled by heat exchange in the fourth heat exchanger 43, thereby reducing the temperature of the oxidizing gas supplied to the fuel cell 2. As a result, the oxidizing gas compressed in the compressor 31 and reaching a relatively high temperature can be cooled to a temperature (about 60° C.) suitable for the chemical reaction in the fuel cell 2 before being supplied to the fuel cell 2. The fourth heat exchanger 43 utilizes the cold and hot energy of the fuel gas before being supplied to the fuel cell 2, so that dedicated pipelines and pumps are not required, and the structure of the fuel cell system 1 can be simplified.

[0097] According to the above configuration, the oxidant gas before being introduced into the compressor 31 is cooled by heat exchange in the fourth heat exchanger 43, thereby reducing the power required for driving (rotating) the compressor 31 (for example, the power consumption of the electric motor 32). It should be noted that the fuel cell system 1 includes the fourth heat exchanger 43, but may be configured not to include at least one of the other heat exchangers and coolers such as the oxidant gas cooler 63.

[0098] (Fifth Heat Exchanger)

[0099] In some embodiments, such as Figure 6 as well as Fig. 9As shown, the above-mentioned fuel cell system 1 also includes: the above-mentioned fourth heat exchanger 43; a fifth heat exchanger 44, which is configured to perform heat exchange between fuel gas and oxidant gas, wherein the fuel gas flows in the fuel gas supply pipeline 4, and the oxidant gas flows in the oxidant gas supply pipeline 3 at a position downstream of the compressor 31.

[0100] The fuel gas guided to the fifth heat exchanger 44 is lower in temperature than the oxidizing gas guided to the fifth heat exchanger 44. Therefore, the oxidizing gas is cooled and the fuel gas is heated by heat exchange in the fifth heat exchanger 44. In the illustrated embodiment, the fifth heat exchanger 44 is provided at a position downstream of the fourth heat exchanger 43 in the fuel gas supply line 4. In addition, the fifth heat exchanger 44 is provided at a position downstream of the compressor 31 and upstream of the oxidizing gas cooler 63 in the oxidizing gas supply line 3.

[0101] According to the above structure, the oxidizing gas supplied to the fuel cell 2 can be cooled by heat exchange in the fifth heat exchanger 44. By utilizing the cold and heat energy of the fuel gas before being supplied to the fuel cell 2 in cooling the oxidizing gas supplied to the fuel cell 2, the cold and heat loss of the cooling system of the fuel cell 2 can be suppressed, and the structure of the fuel cell system 1 can be simplified.

[0102] In some embodiments, such as Figure 7 and Fig.10 As shown, the fuel cell system 1 further includes the fifth heat exchanger 44. Figure 7 and Fig.10 As shown, the fuel cell system 1 may not include the fourth heat exchanger 43 .

[0103] According to the above structure, the oxidizing gas supplied to the fuel cell 2 can be cooled by heat exchange in the fifth heat exchanger 44. By utilizing the cold and heat energy of the fuel gas before supplying to the fuel cell 2 in cooling the oxidizing gas supplied to the fuel cell 2, the cold and heat loss of the cooling system of the fuel cell 2 can be suppressed, and the structure of the fuel cell system 1 can be simplified. It should be noted that the fuel cell system 1 includes the fifth heat exchanger 44, but may be configured not to include at least one of the other heat exchangers and coolers such as the oxidizing gas cooler 63.

[0104] (Sixth Heat Exchanger)

[0105] In some embodiments, such as Fig.11As shown, the above-mentioned fuel cell system 1 also has: the above-mentioned fourth heat exchanger 43; the sixth heat exchanger 45, which is configured to perform heat exchange between the fuel gas and the cold and hot medium, the fuel gas flows in the fuel gas supply pipeline 4, and the cold and hot medium flows in the cold and hot medium supply pipeline 6.

[0106] The fuel gas guided to the sixth heat exchanger 45 is lower in temperature than the cold and hot medium guided to the sixth heat exchanger 45. Therefore, the cold and hot medium is cooled and the fuel gas is heated by heat exchange in the sixth heat exchanger 45. In the illustrated embodiment, the sixth heat exchanger 45 is provided at a position downstream of the fourth heat exchanger 43 in the fuel gas supply line 4. In addition, the sixth heat exchanger 45 is provided in the bypass line 60B (cold and hot medium supply line 6).

[0107] According to the above structure, the cold and hot medium flowing in the cold and hot medium supply pipeline 6 can be cooled by heat exchange in the sixth heat exchanger 45. By utilizing the cold and hot energy of the fuel gas before supplying to the fuel cell 2 in the cooling of the refrigerant, the cold and hot loss of the cooling system of the fuel cell 2 can be suppressed, and the structure of the fuel cell system 1 can be simplified.

[0108] In some embodiments, such as Fig.12 As shown, the above-mentioned fuel cell system 1 further includes the above-mentioned sixth heat exchanger 45. Fig.12 As shown, the fuel cell system 1 may not include the fourth heat exchanger 43 .

[0109] According to the above structure, the cold and hot medium flowing in the cold and hot medium supply pipeline 6 can be cooled by heat exchange in the sixth heat exchanger 45. By utilizing the cold and hot energy of the fuel gas before supplying to the fuel cell 2 in cooling the cold and hot medium, the cold and hot loss of the cooling system of the fuel cell 2 can be suppressed, and the structure of the fuel cell system 1 can be simplified. In addition, the fuel cell system 1 includes the sixth heat exchanger 45, but can also be configured not to include at least one of the other heat exchangers and coolers such as the oxidizing gas cooler 63.

[0110] (Fuel gas storage device)

[0111] In some embodiments, such as Figure 5 to Figure 7 , Fig.11 and Fig.12 As shown, the fuel gas storage device 41 is configured to store the fuel gas in a liquid state. Here, storing the fuel gas in a liquid state means that most of the fuel gas stored in the fuel gas storage device 41 is in a liquid state.

[0112] According to the above configuration, the fuel gas supplied to the fuel cell 2 can be heated by heat exchange in the heat exchanger 43, 44 or 45 using the fuel gas as a heat medium in the fuel gas supply line 4. Thus, the fuel gas supplied to the fuel cell 2 can be gasified and heated to a temperature close to that suitable for the chemical reaction in the fuel cell 2 before being supplied to the fuel cell 2.

[0113] In some embodiments, such as Figure 1 to Figure 4 , Figure 8 to Figure 10 As shown, the fuel gas storage device 41 is configured to store the fuel gas in a gaseous state. Here, storing the fuel gas in a gaseous state means that most of the fuel gas stored in the fuel gas storage device 41 is in a gaseous state. The fuel gas is stored in the fuel gas storage device 41 in a compressed state, and the pressure of the fuel gas in the fuel gas storage device 41 becomes relatively high.

[0114] According to the above configuration, the fuel gas supplied to the fuel cell 2 can be heated by heat exchange in the heat exchanger 43, 44 or 45 using the fuel gas as a heat medium in the fuel gas supply line 4. Thus, the fuel gas supplied to the fuel cell 2 can be heated to a temperature suitable for the chemical reaction in the fuel cell 2 before being supplied to the fuel cell 2.

[0115] (Pressure Reducing Device)

[0116] In some embodiments, such as Figure 8 to Figure 10 As shown, the fuel gas storage device 41 is configured to store the fuel gas in a gaseous state. The fuel cell system 1 is further provided with a pressure reducing device 46, which is configured to be arranged in the fuel gas supply line 4 at a position upstream of the heat exchanger 43, 44 or 45 that uses the fuel gas as a heat medium, and to reduce the pressure of the fuel gas. The pressure reducing device 46 is arranged at a position upstream of the heat exchanger located at the most upstream side among the multiple heat exchangers arranged in the fuel gas supply line 4. The pressure reducing device 46 can be a pressure reducing valve or an expansion turbine as long as it is configured to reduce the pressure of the fuel gas.

[0117] According to the above configuration, the temperature of the fuel gas can be reduced by reducing the pressure of the fuel gas in the pressure reducing device 46. In this case, the temperature of the fuel gas supplied to the heat exchanger 43, 44 or 45 using the fuel gas as a heat medium can be reduced in the fuel gas supply line 4, and in the heat exchanger 43, 44 or 45, the cold and heat energy of the fuel gas can be used to effectively cool the oxidizing gas.

[0118] In this specification, expressions such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" that indicate relative or absolute configurations strictly speaking not only indicate such configurations, but also indicate a state of relative displacement at an angle or distance with a tolerance or a degree that can achieve the same function.

[0119] For example, expressions such as “same”, “equal”, and “homogeneous” indicating a state in which things are equal not only indicate a state of being strictly equal, but also indicate a state in which there is a tolerance or a difference to the extent that the same function can be obtained.

[0120] In the present specification, expressions indicating shapes such as quadrilaterals and cylinders not only indicate shapes such as quadrilaterals and cylinders in a strict geometric sense, but also indicate shapes including concave-convex portions and chamfered portions within a range that can obtain the same effect.

[0121] In addition, in this specification, the expression “having”, “including” or “having” a component is not an exclusive expression that excludes the presence of other components.

[0122] The present disclosure is not limited to the above-described embodiments, and also includes modified embodiments of the above-described embodiments and embodiments in which these embodiments are appropriately combined.

[0123] The contents described in the above-mentioned several embodiments can be understood, for example, as follows.

[0124] 1) A fuel cell system (1) according to at least one embodiment of the present disclosure comprises: a fuel cell (2); an oxidizing gas supply line (3) for conveying oxidizing gas to the fuel cell (2); a compressor (31) arranged on the oxidizing gas supply line (3) and compressing the oxidizing gas; a cold and hot medium supply line (6) for supplying a cold and hot medium for cooling the fuel cell (2) to the fuel cell (2); a cold and hot medium pump (61) arranged on the cold and hot medium supply line (6) and pressurizing the cold and hot medium; and an oxidizing gas cooler (63) arranged to perform heat exchange between the cold and hot medium and the oxidizing gas, wherein the cold and hot medium flows in the cold and hot medium supply line (6), and the oxidizing gas flows at a position on the downstream side of the oxidizing gas supply line (3) relative to the compressor (31) and is compressed by the compressor (31).

[0125] According to the structure of 1) above, the oxidizing gas supplied to the fuel cell (2) can be cooled by heat exchange in the oxidizing gas cooler (63). Thus, the oxidizing gas compressed in the compressor (31) to a relatively high temperature (about 200°C) can be cooled to a temperature (about 60°C) suitable for the chemical reaction in the fuel cell (2) before being supplied to the fuel cell (2). The oxidizing gas cooler (63) uses the cooling system of the fuel cell (2) such as the cold and hot medium supply pipeline (6) and the cold and hot medium pump (61) to supply the cold and hot medium to the oxidizing gas cooler (63), so that dedicated pipelines and pumps are not required, and the structure of the fuel cell system (1) can be simplified.

[0126] 2) In some embodiments, the fuel cell system (1) described in 1) above further comprises: an exhaust pipeline (5) for conveying exhaust gas discharged from the fuel cell (2); a turbine (51) which is arranged on the exhaust pipeline (5) and driven by the exhaust gas; and a first heat exchanger (52) which is configured to perform heat exchange between the exhaust gas and the oxidizing gas, the exhaust gas flowing on the exhaust pipeline (5) at a position downstream of the turbine (51), and the oxidizing gas flowing on the oxidizing gas supply pipeline (3) at a position downstream of the compressor (31).

[0127] According to the structure of 2) above, the oxidizing gas supplied to the fuel cell (2) can be cooled by heat exchange in the first heat exchanger (52). By utilizing the exhaust gas expanded in the turbine (51) and having a relatively low temperature (about 10° C.) in cooling the oxidizing gas supplied to the fuel cell (2), the heat loss of the cooling system of the fuel cell (2) can be suppressed, and the structure of the fuel cell system (1) can be simplified.

[0128] 3) In some embodiments, the fuel cell system (1) described in 2) above further includes a fuel cell cooler (53) configured to cool the fuel cell (2) using the exhaust gas flowing in the exhaust line (5) at a position downstream of the turbine (51).

[0129] According to the structure of 3) above, the fuel cell (2) can be cooled in the fuel cell cooler (53). By utilizing the exhaust gas that has expanded in the turbine (51) and has a relatively low temperature (about 10° C.) in cooling the fuel cell (2), the heat loss of the cooling system of the fuel cell (2) can be suppressed, and the structure of the fuel cell system (1) can be simplified.

[0130] 4) In some embodiments, the fuel cell system (1) described in 1) above further comprises: an exhaust pipeline (5) for conveying exhaust gas discharged from the fuel cell (2); a turbine (51) which is arranged on the exhaust pipeline (5) and driven by the exhaust gas; and a second heat exchanger (54) which is configured to perform heat exchange between the exhaust gas and the cold and hot medium, wherein the exhaust gas flows on the exhaust pipeline (5) at a position downstream of the turbine (51), and the cold and hot medium flows in the cold and hot medium supply pipeline (6).

[0131] According to the structure of 4), the cold and hot medium flowing in the cold and hot medium supply pipeline (6) can be cooled by heat exchange in the second heat exchanger (54). By utilizing the exhaust gas that has expanded in the turbine (51) and has a relatively low temperature (about 10° C.) in cooling the cooling medium, the heat loss of the cooling system of the fuel cell (2) can be suppressed, and the structure of the fuel cell system (1) can be simplified.

[0132] 5) In some embodiments, the fuel cell system (1) described in 1) above further comprises: an exhaust pipeline (5) for conveying exhaust gas discharged from the fuel cell (2); a turbine (51) which is arranged on the exhaust pipeline (5) and driven by the exhaust gas; and a third heat exchanger (55) which is configured to perform heat exchange between the exhaust gas and the oxidizing gas, wherein the exhaust gas flows on the exhaust pipeline (5) at a position upstream of the turbine (51), and the oxidizing gas flows on the oxidizing gas supply pipeline (3) at a position downstream of the compressor (31).

[0133] According to the structure of 5), the oxidizing gas supplied to the fuel cell (2) can be cooled by heat exchange in the third heat exchanger (55). By utilizing the relatively low temperature (about 80° C.) exhaust gas before being introduced into the turbine (51) in cooling the oxidizing gas supplied to the fuel cell (2), the heat loss of the cooling system of the fuel cell (2) can be suppressed, and the structure of the fuel cell system (1) can be simplified.

[0134] According to the structure of 5) above, the exhaust gas before being introduced into the turbine (51) can be heated by heat exchange in the third heat exchanger (55). By raising the temperature of the exhaust gas introduced into the turbine (51), the energy that can be recovered in the turbine (51) can be increased. In the case where the turbine (51) is connected to the compressor (31) via the rotating shaft (33), the amount of assistance provided by the turbine (51) to the drive (rotation) of the compressor (31) can be increased by increasing the energy that can be recovered in the turbine (51). As a result, the power required for the drive (rotation) of the compressor (31) (for example, the power consumption of the electric motor 32) can be reduced.

[0135] 6) In some embodiments, in the fuel cell system (1) described in any one of 2) to 5) above, the compressor (31) includes an electric compressor (31A), and the electric compressor (31A) is configured to be driven by an electric motor (32) to compress the oxidizing gas. The fuel cell system (1) also has a motor cooler (56), and the motor cooler (56) is configured to cool the electric motor (32) by utilizing the exhaust gas flowing in the exhaust pipeline (5) at a position downstream of the turbine (51).

[0136] According to the structure of 6) above, the electric motor (32) can be cooled in the motor cooler (56). By utilizing the exhaust gas that has expanded in the turbine (51) and has a relatively low temperature (about 10° C.) in cooling the electric motor (32), overheating of the electric motor (32) can be suppressed, and the structure of the fuel cell system (1) can be simplified.

[0137] 7) In some embodiments, the fuel cell system (1) described in 1) above further comprises: a fuel gas storage device (41) configured to store fuel gas; a fuel gas supply pipeline (4) for transporting the fuel gas stored in the fuel gas storage device (41) to the fuel cell (2); and a fourth heat exchanger (43) configured to perform heat exchange between the fuel gas and the oxidizing gas, the fuel gas flowing in the fuel gas supply pipeline (4), and the oxidizing gas flowing in the oxidizing gas supply pipeline (3) at a position upstream of the compressor (31).

[0138] According to the structure of 7) above, the temperature of the oxidizing gas supplied to the fuel cell (2) can be lowered by cooling the oxidizing gas before it is introduced into the compressor (31) by utilizing heat exchange in the fourth heat exchanger (43). Thus, the oxidizing gas compressed in the compressor (31) and reaching a relatively high temperature (approximately 200° C.) can be cooled to a temperature (approximately 60° C.) suitable for the chemical reaction in the fuel cell (2) before being supplied to the fuel cell (2). The fourth heat exchanger (43) utilizes the cold and hot energy of the fuel gas before it is supplied to the fuel cell (2), so that dedicated pipelines and pumps are not required, and the structure of the fuel cell system (1) can be simplified.

[0139] According to the structure of 7) above, by utilizing heat exchange in the fourth heat exchanger (43) to cool the oxidizing gas before being introduced into the compressor (31), the power required to drive (rotate) the compressor (31) (for example, the power consumption of the electric motor 32) can be reduced.

[0140] 8) In some embodiments, the fuel cell system (1) described in 7) above further includes a fifth heat exchanger (44) configured to perform heat exchange between the fuel gas and the oxidizing gas, wherein the fuel gas flows in the fuel gas supply pipeline (4) and the oxidizing gas flows in the oxidizing gas supply pipeline (3) at a position downstream of the compressor (3).

[0141] According to the structure of 8), the oxidizing gas supplied to the fuel cell (2) can be cooled by heat exchange in the fifth heat exchanger (44). By utilizing the cold and heat energy of the fuel gas before supply to the fuel cell (2) in cooling the oxidizing gas supplied to the fuel cell (2), the cold and heat loss of the cooling system of the fuel cell (2) can be suppressed, and the structure of the fuel cell system (1) can be simplified.

[0142] 9) In some embodiments, the fuel cell system (1) described in 7) above further comprises a sixth heat exchanger (45) configured to perform heat exchange between the fuel gas and the cold / hot medium, wherein the fuel gas flows in the fuel gas supply pipeline (4) and the cold / hot medium flows in the cold / hot medium supply pipeline (6).

[0143] According to the structure of 9), the cold and hot medium flowing in the cold and hot medium supply pipeline (6) can be cooled by heat exchange in the sixth heat exchanger (45). By utilizing the cold and hot energy of the fuel gas before supplying to the fuel cell (2) in the cooling of the cold and hot medium, the cold and hot loss of the cooling system of the fuel cell (2) can be suppressed, and the structure of the fuel cell system (1) can be simplified.

[0144] 10) In some embodiments, the fuel cell system (1) described in 1) above further comprises: a fuel gas storage device (41) configured to store fuel gas; a fuel gas supply pipeline (4) for transporting the fuel gas stored in the fuel gas storage device (41) to the fuel cell (2); and a fifth heat exchanger (44) configured to perform heat exchange between the fuel gas and the oxidizing gas, the fuel gas flowing in the fuel gas supply pipeline (4), and the oxidizing gas flowing in the oxidizing gas supply pipeline (3) at a position downstream of the compressor (31).

[0145] According to the structure of 10), the oxidizing gas supplied to the fuel cell (2) can be cooled by heat exchange in the fifth heat exchanger (44). By utilizing the cold and heat energy of the fuel gas before supplying to the fuel cell (2) in cooling the oxidizing gas supplied to the fuel cell (2), the cold and heat loss of the cooling system of the fuel cell (2) can be suppressed, and the structure of the fuel cell system (1) can be simplified.

[0146] 11) In some embodiments, the fuel cell system (1) described in 1) above further comprises: a fuel gas storage device (41) configured to store fuel gas; a fuel gas supply pipeline (4) used to transport the fuel gas stored in the fuel gas storage device (41) to the fuel cell (2); and a sixth heat exchanger (45) configured to perform heat exchange between the fuel gas and the cold / hot medium, the fuel gas flowing in the fuel gas supply pipeline (4), and the cold / hot medium flowing in the cold / hot medium supply pipeline (6).

[0147] According to the structure of 11), the cold and hot medium flowing in the cold and hot medium supply pipeline (6) can be cooled by heat exchange in the sixth heat exchanger (45). By utilizing the cold and hot energy of the fuel gas before supplying to the fuel cell (2) in cooling the cold and hot medium, the cold and hot loss of the cooling system of the fuel cell (2) can be suppressed, and the structure of the fuel cell system (1) can be simplified.

[0148] 12) In some embodiments, in the fuel cell system (1) described in any one of 7) to 11) above, the fuel gas storage device (41) is configured to store the fuel gas in a liquid state.

[0149] According to the structure of 12) above, the fuel gas supplied to the fuel cell (2) can be heated by heat exchange in the heat exchanger (43, 44 or 45) using the fuel gas as a heat medium in the fuel gas supply line 4. As a result, the fuel gas supplied to the fuel cell (2) can be gasified and heated to a temperature close to that suitable for the chemical reaction in the fuel cell (2) before being supplied to the fuel cell (2).

[0150] 13) In some embodiments, in the fuel cell system (1) described in any one of 7) to 11) above, the fuel gas storage device (41) is configured to store the fuel gas in a gaseous state.

[0151] According to the structure of 13) above, the fuel gas supplied to the fuel cell (2) can be heated by heat exchange in the heat exchanger (43, 44 or 45) using the fuel gas as a heat medium in the fuel gas supply line 4. Thus, the fuel gas supplied to the fuel cell (2) can be heated to a temperature suitable for the chemical reaction in the fuel cell (2) before being supplied to the fuel cell (2).

[0152] 14) In some embodiments, the fuel cell system (1) described in 13) above is further provided with a pressure reducing device (46), which is configured to be arranged in the fuel gas supply pipeline (4) at a position upstream of the heat exchanger (43, 44 or 45) using the fuel gas as a heat medium, and to reduce the pressure of the fuel gas.

[0153] According to the structure of 14), the temperature of the fuel gas can be lowered by reducing the pressure of the fuel gas in the pressure reducing device (46). In this case, the temperature of the fuel gas supplied to the heat exchanger (43, 44 or 45) using the fuel gas as a heat medium in the fuel gas supply line 4 can be lowered, and in the heat exchanger (43, 44 or 45), the cold and heat energy of the fuel gas can be used to effectively cool the oxidizing gas.

[0154] Description of Reference Numerals

[0155] 1: Fuel cell system

[0156] 2. Fuel Cell

[0157] 3: Oxidizing gas supply line

[0158] 4: Fuel gas supply pipeline

[0159] 5: Exhaust pipeline

[0160] 6: Cold and hot medium supply pipelines

[0161] 20: Power generation unit

[0162] 21: Air pole

[0163] 22: Fuel pole

[0164] 23: Electrolyte membrane

[0165] 31: Compressor

[0166] 31A: Electric compressor

[0167] 32: Electric Motor

[0168] 41: Fuel gas storage device

[0169] 42: First fuel gas flow control valve

[0170] 43: The fourth heat exchanger

[0171] 44: Fifth heat exchanger

[0172] 45: Sixth heat exchanger

[0173] 46: Pressure relief device

[0174] 51: Turbine

[0175] 52: First heat exchanger

[0176] 53: Fuel cell cooler

[0177] 54: Second heat exchanger

[0178] 61: Pumps for hot and cold media

[0179] 62: Electric Motor

[0180] 63: Oxidation gas cooler

[0181] 64: Radiator

Claims

1. A fuel cell system, wherein: have: Fuel cells; an oxidizing gas supply pipeline for delivering oxidizing gas to the fuel cell; a compressor, which is arranged in the oxidizing gas supply line and is configured to compress the oxidizing gas; A cold and hot medium supply pipeline, which is used to supply cold and hot medium for cooling the fuel cell to the fuel cell; A cold and hot medium pump, which is arranged in the cold and hot medium supply pipeline and increases the pressure of the cold and hot medium; The oxidizing gas cooler is configured to perform heat exchange between the cold / hot medium and the oxidizing gas, the cold / hot medium flowing in the cold / hot medium supply line, and the oxidizing gas flowing in the oxidizing gas supply line at a position downstream of the compressor and compressed by the compressor.

2. The fuel cell system according to claim 1, wherein: Also available: an exhaust line for conveying exhaust gas exhausted from the fuel cell; a turbine configured to be disposed in the exhaust line and driven by the exhaust gas; The first heat exchanger is configured to perform heat exchange between the exhaust gas flowing in the exhaust line at a position downstream of the turbine and the oxidizing gas flowing in the oxidizing gas supply line at a position downstream of the compressor.

3. The fuel cell system according to claim 2, wherein: A fuel cell cooler is further provided, the fuel cell cooler being configured to cool the fuel cell using the exhaust gas flowing in the exhaust line at a position downstream of the turbine.

4. The fuel cell system according to claim 1, wherein: Also available: an exhaust line for conveying exhaust gas exhausted from the fuel cell; a turbine configured to be disposed in the exhaust line and driven by the exhaust gas; The second heat exchanger is configured to perform heat exchange between the exhaust gas flowing in the exhaust line at a position downstream of the turbine and the cold / heat medium flowing in the cold / heat medium supply line.

5. The fuel cell system according to claim 1, wherein: Also available: an exhaust line for conveying exhaust gas exhausted from the fuel cell; a turbine configured to be disposed in the exhaust line and driven by the exhaust gas; The third heat exchanger is configured to perform heat exchange between the exhaust gas flowing in the exhaust line at a position upstream of the turbine and the oxidizing gas flowing in the oxidizing gas supply line at a position downstream of the compressor.

6. The fuel cell system according to any one of claims 2 to 4, wherein: The compressor includes an electric compressor, and the electric compressor is configured to be driven by an electric motor to compress the oxidizing gas. The fuel cell system further includes a motor cooler configured to cool the electric motor using the exhaust gas flowing in the exhaust line at a position downstream of the turbine.

7. The fuel cell system according to claim 1, wherein: Also available: a fuel gas storage device configured to store fuel gas; a fuel gas supply pipeline for delivering the fuel gas stored in the fuel gas storage device to the fuel cell; The fourth heat exchanger is configured to perform heat exchange between the fuel gas flowing in the fuel gas supply line and the oxidizing gas flowing in the oxidizing gas supply line at a position upstream of the compressor.

8. The fuel cell system according to claim 7, wherein: A fifth heat exchanger is further provided, the heat exchanger being configured to perform heat exchange between the fuel gas flowing in the fuel gas supply line and the oxidizing gas flowing in the oxidizing gas supply line at a position downstream of the compressor.

9. The fuel cell system according to claim 7, wherein: A sixth heat exchanger is further provided, the heat exchanger being configured to perform heat exchange between the fuel gas flowing through the fuel gas supply line and the cold / heat medium flowing through the cold / heat medium supply line.

10. The fuel cell system according to claim 1, wherein: Also available: a fuel gas storage device configured to store fuel gas; a fuel gas supply pipeline for delivering the fuel gas stored in the fuel gas storage device to the fuel cell; The fifth heat exchanger is configured to perform heat exchange between the fuel gas flowing in the fuel gas supply line and the oxidizing gas flowing in the oxidizing gas supply line at a position downstream of the compressor.

11. The fuel cell system according to claim 1, wherein: Also available: a fuel gas storage device configured to store fuel gas; a fuel gas supply pipeline for delivering the fuel gas stored in the fuel gas storage device to the fuel cell; The sixth heat exchanger is configured to perform heat exchange between the fuel gas and the cold / heat medium, the fuel gas flowing in the fuel gas supply line and the cold / heat medium flowing in the cold / heat medium supply line.

12. The fuel cell system according to any one of claims 7 to 11, wherein: The fuel gas storage device is configured to store the fuel gas in a liquid state.

13. The fuel cell system according to any one of claims 7 to 11, wherein: The fuel gas storage device is configured to store the fuel gas in a gaseous state.

14. The fuel cell system according to claim 13, wherein: A decompression device is further provided, the decompression device being provided in the fuel gas supply line at an upstream side of the heat exchanger using the fuel gas as a heat medium and being configured to decompress the fuel gas.

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