Fuel cell power generation system

Abstract

To provide a fuel cell power generation system that suppresses the generation of white smoke in exhaust emissions.SOLUTION: A fuel cell power generation system includes a fuel cell unit that generates power by causing a chemical reaction between hydrogen and oxygen, a coolant supply unit that supplies coolant to cool the fuel cell unit, and an exhaust cooling unit that cools the exhaust from the fuel cell unit using the coolant.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to fuel cell power generation systems. [Background technology]

[0002] Patent Document 1 discloses a packaged fuel cell power generation system that houses in one package a reformer, a battery that reacts hydrogen and oxygen to obtain electric energy, a heat exchanger for maintaining reaction conditions and increasing plant efficiency, and a control system. Patent Document 1 discloses that the fuel cell power generation system is provided with a cooling means that cools the plant exhaust after recovering heat and water from the reformer exhaust gas and the battery exhaust air before releasing it into the atmosphere, and condenses and recovers water vapor in the plant exhaust.

[0003] Patent Document 2 discloses a fuel cell power generation system that includes all of the main equipment of the power generation system, including a fuel cell, a fuel reformer, etc., and a generated water recovery device that condenses and recovers generated water contained in the air off-gas of the fuel cell and the combustion exhaust gas of the fuel reformer. Patent Document 2 discloses that all of the main equipment in the fuel cell power generation system and the generated water recovery device are housed together in a package that is forcibly ventilated by a ventilation fan. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 09-223510 [Patent Document 2] Japanese Patent Application Publication No. 08-293316 Summary of the Invention [Problem to be solved by the invention]

[0005] Stationary fuel cell power generation systems are often installed in places where they are visible to the public. When stationary fuel cell power generation systems emit white smoke during exhaust, some people may find it unpleasant.

[0006] The present disclosure provides a fuel cell power generation system that suppresses the generation of white smoke in the exhaust. [Means for solving the problem]

[0007] According to one aspect of the present disclosure, there is provided a fuel cell power generation system comprising a fuel cell section that generates power by chemically reacting hydrogen and oxygen, a coolant supply section that supplies a coolant for cooling the fuel cell section, and an exhaust cooling section that cools exhaust gas from the fuel cell section using the coolant. Effect of the Invention

[0008] According to the fuel cell power generation system of the present disclosure, the generation of white smoke in the exhaust can be suppressed. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing an outline of the configuration of a fuel cell power generation system according to a first embodiment. [Diagram 2] FIG. 2 is a diagram showing an outline of the configuration of a fuel cell power generation system according to the second embodiment. [Diagram 3] FIG. 3 is a diagram showing an outline of the configuration of a fuel cell power generation system according to the third embodiment. [Figure 4] FIG. 4 is a diagram showing an outline of the configuration of a fuel cell power generation system according to a fourth embodiment. [Diagram 5] FIG. 5 is a diagram showing an outline of the configuration of a fuel cell power generation system according to a fifth embodiment. [Figure 6] FIG. 6 is a diagram showing an outline of the configuration of a fuel cell power generation system according to a sixth embodiment. [Figure 7] FIG. 7 is a diagram showing an outline of the configuration of a fuel cell power generation system according to a seventh embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments will be described with reference to the accompanying drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0011] In addition, in the description of the specification and drawings of each embodiment, components having substantially the same or corresponding functional configurations may be denoted by the same reference numerals to avoid redundant explanation. In addition, in order to facilitate understanding, the scale of each part in the drawings may differ from the actual scale.

[0012] First Embodiment We will now explain the fuel cell power generation system according to the first embodiment. The fuel cell power generation system according to the first embodiment includes a fuel cell unit that generates electricity by chemically reacting hydrogen and oxygen, a coolant supply unit that supplies a coolant for cooling the fuel cell unit, and an exhaust gas cooling unit that cools the exhaust gas from the fuel cell unit with the coolant.

[0013] A fuel cell power generation system according to a first embodiment will be described with reference to the drawings. Fig. 1 is a diagram showing an outline of the configuration of a fuel cell power generation system 1, which is an example of the fuel cell power generation system according to the first embodiment.

[0014] The fuel cell power generation system 1 is a system that generates electricity using a fuel cell unit 10 that generates electricity by chemically reacting hydrogen and oxygen. The fuel cell power generation system 1 supplies the generated electricity to a destination.

[0015] The fuel cell power generation system 1 includes a fuel cell section 10, a coolant supply section 20, and an exhaust gas cooling section 30.

[0016] [Fuel cell section 10] The fuel cell unit 10 generates electricity by chemically reacting hydrogen and oxygen. The fuel cell unit 10 includes a fuel cell stack 11, a heat exchanger 12, and a pump 13.

[0017] The fuel cell stack 11 provided in the fuel cell section 10 generates heat when generating electricity. A coolant RF1 is supplied to the fuel cell section 10 from a coolant supply section 20. The coolant RF1 flows from the coolant supply section 20 to the exhaust cooling section 30 and then to the fuel cell section 10 in this order.

[0018] The fuel cell section 10 includes a fuel cell stack 11 that generates electricity by chemically reacting hydrogen with oxygen. The fuel cell stack 11 generates electricity by chemically reacting supplied hydrogen with oxygen contained in the air. The fuel cell stack 11 is, for example, a polymer electrolyte fuel cell (PEFC). The fuel cell stack 11, which is a polymer electrolyte fuel cell, has a stack structure in which a large number of unit cells are stacked.

[0019] A single cell in the fuel cell stack 11, which is a solid polymer electrolyte fuel cell, includes a membrane electrode assembly (MEA) including a polymer electrolyte membrane and a pair of electrodes provided on both sides of the polymer electrolyte membrane. The polymer electrolyte membrane selectively transports hydrogen ions. Each of the pair of electrodes is formed of a porous material. Each of the pair of electrodes includes a catalyst layer mainly composed of carbon powder supporting a platinum-based metal catalyst (electrode catalyst), for example, and a gas diffusion layer having both air permeability and electronic conductivity. Furthermore, the single cell includes a pair of separators that sandwich the membrane electrode assembly (MEA) from both sides.

[0020] The electricity generated by the fuel cell stack 11 is boosted and output to the outside.

[0021] The fuel cell stack 11 generates electricity by chemically reacting hydrogen SH supplied from the outside with air SA. Then, exhaust EH containing hydrogen that remains unreacted is exhausted from the hydrogen electrode side of the fuel cell stack 11. Also, exhaust EA, which is air SA from which oxygen has been consumed, is exhausted from the oxygen electrode side of the fuel cell stack 11. Then, the exhaust EH and the exhaust EA are mixed and exhausted as exhaust EX. Note that a portion of the exhaust EH may be returned to the inlet side of the hydrogen electrode.

[0022] The fuel cell section 10 is cooled by a coolant RF1 supplied from a coolant supply section 20. In the fuel cell section 10, the fuel cell stack 11 is cooled by a coolant RF2 that has exchanged heat with the coolant RF1 by a heat exchanger 12. In other words, the fuel cell stack 11 is not directly cooled by the coolant RF1, but is indirectly cooled by the coolant RF1 via the coolant RF2.

[0023] The heat exchanger 12 exchanges heat between the coolant RF1 and the coolant RF2. The heat exchanger 12 includes a heat exchanger that exchanges heat between the coolant RF1 and the coolant RF2.

[0024] The fuel cell section 10 is supplied with coolant RF1c, which is the coolant RF1 that is supplied from the coolant supply section 20 to the exhaust cooling section 30 and discharged from the exhaust cooling section 30. The heat exchanger 12 exchanges heat between the supplied coolant RF1c and coolant RF2. The coolant RF1c that has exchanged heat in the heat exchanger 12 increases in temperature and is discharged as coolant RF1d. The discharged coolant RF1d is collected in the coolant supply section 20.

[0025] Furthermore, the coolant RF2 cooled in the heat exchanger 12 is discharged as coolant RF2a from the heat exchanger 12 to the fuel cell section 10. The coolant RF2a is sent to the fuel cell section 10 by the pump 13. The coolant RF2 sent to the fuel cell section 10 is heated by cooling the fuel cell stack 11. The coolant RF2 heated in the fuel cell section 10 is discharged to the heat exchanger 12 as coolant RF2b.

[0026] The heat exchanger 12 heats the cooling liquid RF1c and discharges it as the cooling liquid RF1d, and also cools the cooling liquid RF2b and discharges it as the cooling liquid RF2a.

[0027] It should be noted that the fuel cell section 10 may not include the heat exchanger 12 and the fuel cell stack 11 may be directly cooled by the coolant RF1.

[0028] [Cooling fluid supply section 20] The coolant supply unit 20 supplies coolant RF1 for cooling the fuel cell unit 10. More specifically, the coolant supply unit 20 supplies coolant RF1 for cooling the fuel cell stack 11 in the fuel cell unit 10. In the fuel cell unit 10, the coolant RF1 exchanges heat with coolant RF2 by the heat exchanger 12. As a result of the heat exchange between the coolant RF1 and the coolant RF2, the coolant RF1 indirectly cools the fuel cell stack 11.

[0029] The coolant supply unit 20 is, for example, a chiller (coolant circulation device) or a cooling tower. The coolant supply unit 20 discharges the cooled coolant RF1 as coolant RF1a. The coolant RF1a discharged from the coolant supply unit 20 is supplied to the exhaust cooling unit 30. The coolant supply unit 20 recovers coolant RF1d, which is the coolant RF1 discharged from the fuel cell unit 10.

[0030] [Exhaust Cooling Section 30] The exhaust cooling section 30 cools the exhaust EX discharged from the fuel cell section 10. The exhaust cooling section 30 includes a heat exchanger that exchanges heat between the coolant RF1 and the exhaust EX. The cooled coolant RF1a is supplied to the exhaust cooling section 30 from the coolant supply section 20. The exhaust cooling section 30 exchanges heat between the supplied coolant RF1a and the exhaust EX.

[0031] The low-temperature coolant RF1a supplied to the exhaust gas cooling section 30 is heated by heat exchange with the exhaust gas EX. Meanwhile, the exhaust gas EX that has exchanged heat with the coolant RF1a is cooled. When the exhaust gas EX is cooled, condensed water CW, which is the water vapor contained in the exhaust gas EX that is condensed, is discharged.

[0032] The coolant RF1a that has exchanged heat with the exhaust gas EX in the exhaust gas cooling section 30 is discharged as coolant RF1c whose temperature is higher than that of the coolant RF1a. The coolant RF1c is supplied to the fuel cell section 10.

[0033] Furthermore, exhaust gas EXa cooled by the coolant RF1a is discharged from the exhaust gas cooling section 30. The exhaust gas EXa is mixed with and diluted by the air RA in the space in which the fuel cell section 10 is installed. The exhaust gas EXa diluted by the air RA is discharged to the outside as exhaust gas EXb.

[0034] According to the fuel cell power generation system of the first embodiment, the exhaust gas is cooled in the exhaust gas cooling section, and the water vapor contained in the exhaust gas is condensed, thereby suppressing the generation of white smoke. Also, according to the fuel cell power generation system of the first embodiment, the exhaust gas in the fuel cell section is cooled by the cooling liquid for cooling the fuel cell section, so that there is no need to provide a separate cooling device for cooling the exhaust gas, and therefore the system can be made compact.

[0035] Second Embodiment A fuel cell power generation system according to the second embodiment will be described. The fuel cell power generation system according to the second embodiment further includes an exhaust heat recovery unit that recovers exhaust heat from the coolant whose temperature has increased due to heat in the fuel cell unit, in addition to the components of the fuel cell power generation system according to the first embodiment.

[0036] A fuel cell power generation system according to a second embodiment will be described with reference to the drawings. Fig. 2 is a diagram showing an outline of the configuration of a fuel cell power generation system 2, which is an example of a fuel cell power generation system according to the second embodiment. Note that for configurations common to the fuel cell power generation system 1, the description of the fuel cell power generation system 1 should be referred to, and description thereof will be omitted here. The same applies to the following embodiments.

[0037] The fuel cell power generation system 2 further includes an exhaust heat recovery section 40 in addition to the components of the fuel cell power generation system 1 .

[0038] [Waste heat recovery section 40] The exhaust heat recovery unit 40 recovers exhaust heat from the coolant RF1, more specifically, from the coolant RF1d, whose temperature has increased due to the heat in the fuel cell unit 10. The exhaust heat recovery unit 40 is, for example, a water heater, a space heater, a boiler feed water heater, an absorption chiller, or a binary power generation device.

[0039] The exhaust heat recovery section 40 discharges the coolant RF1a supplied from the coolant supply section 20 as coolant RF1b to the exhaust cooling section 30. The exhaust heat recovery section 40 may, for example, heat or cool the coolant RF1a while the supplied coolant RF1a is being discharged as coolant RF1b.

[0040] In the fuel cell power generation system 2, the exhaust cooling section 30 exchanges heat between the exhaust EX and a coolant RF1b supplied from the exhaust heat recovery section 40. In addition, the fuel cell section 10 discharges a coolant RF1d to the exhaust heat recovery section 40.

[0041] The exhaust heat recovery unit 40 discharges the coolant RF1d supplied from the fuel cell unit 10 as coolant RF1e to the coolant supply unit 20. While discharging the supplied coolant RF1d as coolant RF1e, the exhaust heat recovery unit 40 recovers exhaust heat, for example, from the coolant RF1 to heat, for example, water or air.

[0042] In addition to the advantageous effects of the fuel cell power generation system according to the first embodiment, the fuel cell power generation system according to the second embodiment can recover heat in the fuel cell section as exhaust heat. Furthermore, the fuel cell power generation system according to the second embodiment can recover heat in the fuel cell section as exhaust heat, thereby enabling efficient use of energy.

[0043] Third Embodiment A fuel cell power generation system according to the third embodiment will be described. In the fuel cell power generation system according to the third embodiment, in the fuel cell power generation system according to the second embodiment, a coolant cools the auxiliary unit for operating the fuel cell unit between the exhaust cooling unit and the fuel cell unit.

[0044] A fuel cell power generation system according to a third embodiment will be described with reference to the drawings. Fig. 3 is a diagram showing an outline of the configuration of a fuel cell power generation system 3, which is an example of the fuel cell power generation system according to the third embodiment.

[0045] The fuel cell power generation system 3 further includes an auxiliary unit 70 in addition to the components of the fuel cell power generation system 2 .

[0046] [Auxiliary Equipment Section 70] The auxiliary section 70 includes an auxiliary 71 for operating the fuel cell section 10. The auxiliary section 70 includes, as the auxiliary 71, for example, an air compressor and a boost converter. The auxiliary 71 in the auxiliary section 70 is cooled by the coolant RF21 that has exchanged heat with the coolant RF1. The auxiliary section 70 includes a heat exchanger 72 that exchanges heat between the coolant RF1 and the coolant RF21.

[0047] In the fuel cell power generation system 3, the coolant RF1c is supplied from the exhaust cooling section 30 to the auxiliary section 70. The heat exchanger 72 exchanges heat between the coolant RF21 that cools the auxiliary section 71 and the coolant RF1. The heat exchanger 72 discharges the coolant RF1c after heat exchange to the fuel cell section 10 as the coolant RF1c1.

[0048] In addition, in the auxiliary section 70, the heat exchanger 72 may not be provided, and the auxiliary 71 may be directly cooled by the coolant RF1.

[0049] According to the fuel cell power generation system of the third embodiment, in addition to the advantageous effects of the fuel cell power generation system of the second embodiment, the auxiliary parts for operating the fuel cell part can also be cooled.

[0050] In this embodiment, the coolant RF1 cools the exhaust cooling section 30, the auxiliary section 70, and the fuel cell section 10 in that order, but the order may be different.

[0051] Fourth Embodiment A fuel cell power generation system according to the fourth embodiment will be described. The fuel cell power generation system according to the fourth embodiment includes an exhaust heating section that heats the exhaust gas cooled in the exhaust gas cooling section with the cooling liquid after cooling the fuel cell section in the fuel cell power generation system according to the third embodiment.

[0052] A fuel cell power generation system according to a fourth embodiment will be described with reference to the drawings. Fig. 4 is a diagram showing an outline of the configuration of a fuel cell power generation system 4, which is an example of the fuel cell power generation system according to the fourth embodiment.

[0053] The fuel cell power generation system 4 further includes an exhaust heating section 31 in addition to the components of the fuel cell power generation system 3 .

[0054] [Exhaust Heater 31] The exhaust heating section 31 heats the exhaust EXa cooled in the exhaust cooling section 30. The exhaust heating section 31 includes a heat exchanger that exchanges heat between the coolant RF1 and the exhaust EX. Heated coolant RF1d is supplied to the exhaust heating section 31 from the fuel cell section 10. The exhaust heating section 31 exchanges heat between the supplied coolant RF1d and the exhaust EXa.

[0055] The high-temperature coolant RF1d supplied to the exhaust heating section 31 is cooled by exchanging heat with the exhaust EXa. Meanwhile, the exhaust EXa that has exchanged heat with the coolant RF1d is heated. When the exhaust EXa1 is heated, the relative humidity decreases, so that the generation of white smoke can be further suppressed.

[0056] The coolant RF1 that has exchanged heat with the exhaust gas EX in the exhaust gas heating section 31 is discharged as coolant RF1d1 whose temperature is higher than that of the coolant RF1a. The coolant RF1d1 is supplied to the exhaust heat recovery section 40. Furthermore, the exhaust gas EXa1 heated by the coolant RF1d is discharged from the exhaust gas heating section 31. The exhaust gas EXa1 is mixed with and diluted by the air RA in the space in which the fuel cell section 10 is installed. The exhaust gas EXa1 diluted by the air RA is discharged to the outside as exhaust gas EXb1.

[0057] According to the fuel cell power generation system of the fourth embodiment, in addition to the advantageous effects of the fuel cell power generation system of the third embodiment, the generation of white smoke can be further suppressed.

[0058] Fifth embodiment A fuel cell power generation system according to a fifth embodiment will be described. The fuel cell power generation system according to the fifth embodiment includes a fuel cell section that generates power by chemically reacting hydrogen and oxygen, an auxiliary section for operating the fuel cell section, an exhaust cooling section that cools exhaust gas in the fuel cell section, and a coolant supply section that supplies a coolant for cooling. The fuel cell power generation system according to the fifth embodiment further includes an exhaust heat recovery section that individually supplies a coolant to each of the fuel cell section, the auxiliary section, and the exhaust cooling section, and individually recovers exhaust heat discharged by the coolant from each of the fuel cell section, the auxiliary section, and the exhaust cooling section.

[0059] A fuel cell power generation system according to a fifth embodiment will be described with reference to the drawings. Fig. 5 is a diagram showing an outline of the configuration of a fuel cell power generation system 5, which is an example of the fuel cell power generation system according to the fifth embodiment.

[0060] The fuel cell power generation system 5 includes an exhaust heat recovery section 45 instead of the exhaust heat recovery section 40 in the fuel cell power generation system 3 .

[0061] [Waste heat recovery section 45] The exhaust heat recovery unit 45 supplies the coolant RF1 to each of the fuel cell unit 10, the exhaust cooling unit 30, and the auxiliary unit 70. The exhaust heat recovery unit 45 then individually recovers the exhaust heat discharged by the coolant RF1 from each of the fuel cell unit 10, the exhaust cooling unit 30, and the auxiliary unit 70. The exhaust heat recovery unit 45 is, for example, a water heater, a heating appliance, a boiler feed water heater, an absorption chiller, or a binary power generation device.

[0062] The exhaust heat recovery unit 45 supplies the coolant RF1a supplied from the coolant supply unit 20 as the coolant RF1b1 to the fuel cell unit 10. The exhaust heat recovery unit 45 may, for example, heat or cool the coolant RF1a while discharging the supplied coolant RF1a as the coolant RF1b1. The exhaust heat recovery unit 45 supplies the coolant RF1a supplied from the coolant supply unit 20 as the coolant RF1b2 to the auxiliary unit 70. The exhaust heat recovery unit 45 may, for example, heat or cool the coolant RF1a while discharging the supplied coolant RF1a as the coolant RF1b2. The exhaust heat recovery unit 45 supplies the coolant RF1a supplied from the coolant supply unit 20 to the exhaust cooling unit 30 as the coolant RF1b3. The exhaust heat recovery unit 45 may, for example, heat or cool the supplied coolant RF1a while discharging the coolant RF1a as the coolant RF1b3.

[0063] The exhaust heat recovery unit 45 recovers exhaust heat from the coolant RF1d discharged from the fuel cell unit 10, and heats, for example, water or air. The exhaust heat recovery unit 45 also recovers exhaust heat from the coolant RF1c2 discharged from the auxiliary unit 70, and heats, for example, water or air. The exhaust heat recovery unit 45 also recovers exhaust heat from the coolant RF1c3 discharged from the exhaust cooling unit 30, and heats, for example, water or air.

[0064] According to the fuel cell power generation system of the fifth embodiment, in addition to the advantageous effects of the fuel cell power generation system of the third embodiment, the fuel cell section, the exhaust cooling section, and the auxiliary section can each be efficiently cooled. According to the fuel cell power generation system of the fifth embodiment, the exhaust heat can each be efficiently recovered from the fuel cell section, the exhaust cooling section, and the auxiliary section.

[0065] Although not shown in Fig. 5, an adjustment mechanism for adjusting the flow rate distribution ratio of the coolant RF1b1, the coolant RF1b2, and the coolant RF1b3 may be provided. Specific examples of the adjustment mechanism include an adjustment valve, an orifice, and a flow rate controller.

[0066] Sixth Embodiment A fuel cell power generation system according to the sixth embodiment will be described. The fuel cell power generation system according to the sixth embodiment includes a fuel cell unit that generates electricity by chemically reacting hydrogen and oxygen, a coolant supply unit that supplies a coolant, and an exhaust cooling unit that sprays the coolant directly onto the exhaust gas in the fuel cell unit for cooling.

[0067] A fuel cell power generation system according to a sixth embodiment will be described with reference to the drawings. Fig. 6 is a diagram showing an outline of the configuration of a fuel cell power generation system 6, which is an example of the fuel cell power generation system according to the sixth embodiment.

[0068] The fuel cell power generation system 6 includes an exhaust cooling section 130 instead of the exhaust cooling section 30 in the fuel cell power generation system 2. The fuel cell power generation system 6 further includes a coolant supply section 120 and an exhaust heat recovery section 140.

[0069] [Cooling fluid supply section 120] The coolant supply unit 120 supplies a coolant RF3 for cooling the exhaust gas EX discharged from the fuel cell unit .

[0070] The coolant supply unit 120 is, for example, a chiller (coolant circulation device), a cooling tower, or an air-cooled cooler. The coolant supply unit 120 discharges the cooled coolant RF3 as coolant RF3a. The coolant RF3a discharged from the coolant supply unit 120 is supplied to the exhaust heat recovery unit 140. The coolant supply unit 120 recovers coolant RF3d, which is high-temperature coolant RF3, from the exhaust heat recovery unit 140.

[0071] [Exhaust cooling section 130] The exhaust cooling section 130 includes a direct contact heat exchanger. The exhaust cooling section 130 directly sprays the coolant RF3 into the exhaust EX. The exhaust cooling section 130 exchanges heat with the exhaust EX by directly spraying the coolant RF3 into the exhaust EX.

[0072] The exhaust cooling section 130 is supplied with coolant RF3b, which is a low-temperature coolant RF3, from the exhaust heat recovery section 140. The low-temperature coolant RF3b supplied to the exhaust cooling section 130 is heated by heat exchange with the exhaust EX. The exhaust EX that has exchanged heat with the coolant RF3 is cooled. When the exhaust EX is cooled, the water vapor contained in the exhaust EX condenses and mixes with the sprayed coolant RF3b. The condensed water mixed with the coolant RF3b is used as the coolant RF3. In other words, the coolant RF3b contains condensed water obtained by cooling and condensing the exhaust EX. By using the condensed water obtained by cooling and condensing the exhaust EX as the coolant RF3, the water vapor generated by the fuel cell section 10 can be reused. In addition, a part of the coolant RF3 is discharged as wastewater WW.

[0073] The coolant RF3 that has exchanged heat with the exhaust gas EX in the exhaust gas cooling section 130 is discharged as coolant RF3c whose temperature is higher than that of the coolant RF3b. The coolant RF3c is supplied to the exhaust heat recovery section 140. Furthermore, the exhaust gas EXa cooled by the coolant RF3 is discharged from the exhaust gas cooling section 130. The exhaust gas EXa is mixed with the air RA in the space in which the fuel cell section 10 is installed, and is discharged to the outside as exhaust gas EXb.

[0074] [Waste heat recovery section 140] The exhaust heat recovery unit 140 recovers the exhaust heat of the coolant RF3 that has exchanged heat with the exhaust gas EX. The exhaust heat recovery unit 140 is, for example, a water heater, a heating appliance, a heater for boiler feed water, an absorption chiller, or a binary power generation device.

[0075] The exhaust heat recovery unit 140 discharges the coolant RF3a supplied from the coolant supply unit 120 as the coolant RF3b to the exhaust cooling unit 130. The exhaust heat recovery unit 140 may, for example, heat or cool the coolant RF3a while the supplied coolant RF3a is being discharged as the coolant RF3b.

[0076] The exhaust heat recovery unit 140 discharges the coolant RF3c supplied from the exhaust cooling unit 130 as coolant RF3d to the coolant supply unit 120. While discharging the supplied coolant RF3c as coolant RF3d, the exhaust heat recovery unit 140 recovers, for example, exhaust heat from the coolant RF3c to heat, for example, water or air.

[0077] According to the fuel cell power generation system of the sixth embodiment, the exhaust gas is cooled in the exhaust gas cooling section, and the water vapor contained in the exhaust gas is condensed, thereby suppressing the generation of white smoke. Also, according to the fuel cell power generation system of the sixth embodiment, the condensed water condensed in the exhaust gas cooling section 130 can be reused as a coolant.

[0078] Seventh Embodiment <Fuel cell power generation system> A description will now be given of a fuel cell power generation system according to a seventh embodiment. The fuel cell power generation system according to the seventh embodiment cools exhaust gas from a plurality of fuel cell units.

[0079] A fuel cell power generation system according to a seventh embodiment will be described with reference to the drawings. Fig. 7 is a diagram showing an outline of the configuration of a fuel cell power generation system 7, which is an example of the fuel cell power generation system according to the seventh embodiment.

[0080] The fuel cell power generation system 7 includes two fuel cell sections 10. The exhaust cooling section 130 cools the exhaust gases from the two fuel cell sections 10. In the fuel cell power generation system according to the seventh embodiment, the number of fuel cell sections is not limited to two, and may be three or more.

[0081] In the example of Figure 7, an example has been described in which a fuel cell power generation system according to the sixth embodiment is provided with multiple fuel cell sections 10, but the fuel cell power generation systems according to the first to fifth embodiments may also be provided with multiple fuel cell sections.

[0082] According to the fuel cell power generation system of the seventh embodiment, in addition to the advantageous effects of the fuel cell power generation systems of the first to sixth embodiments, by providing multiple fuel cell sections, the output of the fuel cell power generation system can be improved.

[0083] As described above, the embodiment has been described, but the above embodiment is presented as an example, and the present invention is not limited to the above embodiment. The above embodiment can be implemented in various other forms, and various combinations, omissions, substitutions, modifications, etc. can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0084] 1, 2, 3, 4, 5, 6, 7 Fuel cell power generation system 10 Fuel cell section 11 Fuel Cell Stack 12 Heat exchanger 20, 120 Coolant supply section 30, 130 Exhaust cooling section 31 Exhaust Heating Section 40, 45, 140 Exhaust heat recovery section 70 Auxiliary Machinery Section 71 Auxiliary Machine 72 Heat exchanger CW Condensed water EX, EXa, EXa1, EXb, EXb1 Exhaust RA Air RF1, RF3 Coolant SA Air SH Hydrogen

Claims

1. A fuel cell unit that generates electricity by chemically reacting hydrogen and oxygen; a coolant supply unit that supplies a coolant for cooling the fuel cell unit; an exhaust cooling unit that cools exhaust gas from the fuel cell unit by the cooling liquid; Equipped with Fuel cell power generation system.

2. a heat recovery unit that recovers heat from the cooling liquid whose temperature has increased due to heat in the fuel cell unit; The fuel cell power generation system according to claim 1 .

3. The cooling liquid discharged from the cooling liquid supply unit flows in the order of the exhaust cooling unit and the fuel cell unit. The fuel cell power generation system according to claim 2 .

4. The cooling liquid cools an auxiliary unit for operating the fuel cell unit between the exhaust cooling unit and the fuel cell unit. The fuel cell power generation system according to claim 3 .

5. an exhaust gas heating section that heats the exhaust gas cooled in the exhaust gas cooling section by the cooling liquid after cooling the fuel cell section; The fuel cell power generation system according to claim 2 .

6. A plurality of the fuel cell units are provided, The exhaust cooling unit cools the exhaust of the plurality of fuel cell units. The fuel cell power generation system according to any one of claims 1 to 5.

7. The exhaust gas cooled in the exhaust gas cooling section is further diluted with air. The fuel cell power generation system according to any one of claims 1 to 5.

8. A fuel cell unit that generates electricity by chemically reacting hydrogen and oxygen; an auxiliary unit for operating the fuel cell unit; an exhaust cooling unit that cools exhaust gas from the fuel cell unit; A coolant supply unit that supplies a coolant for cooling; an exhaust heat recovery unit that supplies the cooling liquid to each of the fuel cell unit, the auxiliary unit, and the exhaust cooling unit, and recovers exhaust heat discharged by the cooling liquid from each of the fuel cell unit, the auxiliary unit, and the exhaust cooling unit, respectively; Equipped with Fuel cell power generation system.

9. A fuel cell unit that generates electricity by chemically reacting hydrogen and oxygen; a coolant supply unit that supplies a coolant; an exhaust cooling unit that directly sprays the cooling liquid onto the exhaust gas in the fuel cell unit to cool it; Equipped with Fuel cell power generation system.

10. The cooling liquid includes condensed water obtained by cooling and condensing the exhaust gas. The fuel cell power generation system according to claim 9.

11. A plurality of the fuel cell units are provided, The exhaust cooling unit cools the exhaust of the plurality of fuel cell units. The fuel cell power generation system according to any one of claims 8 to 10.

12. The exhaust gas cooled in the exhaust gas cooling section is further diluted with air. The fuel cell power generation system according to any one of claims 8 to 10.

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