JP7556445B1 - Fuel Cell Power Generation System - Google Patents

Abstract

The present disclosure provides a fuel cell power generation system that suppresses the generation of white smoke in the exhaust.
[Solution] A fuel cell power generation system comprising a fuel cell section that generates electricity 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 the exhaust gas from the fuel cell section using the coolant.
[Selected Figure] Figure 1

Description

This disclosure relates to a fuel cell power generation system.

Patent Document 1 discloses a packaged fuel cell power generation system that houses in a single package a reformer, a battery that reacts hydrogen and oxygen to obtain electrical energy, a heat exchanger for maintaining reaction conditions and increasing plant efficiency, and a control system. Patent Document 1 also 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 the water vapor in the plant exhaust.

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 the 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.

Japanese Patent Application Publication No. 09-223510 Japanese Patent Application Publication No. 08-293316

Stationary fuel cell power generation systems may be installed in places where they are visible to the public. When stationary fuel cell power generation systems are exhausted, they give off white smoke that some people find unpleasant.

This disclosure provides a fuel cell power generation system that suppresses the generation of white smoke in the exhaust.

According to one aspect of the present disclosure, a fuel cell power generation system is provided that includes a fuel cell unit that generates power by chemically reacting hydrogen and oxygen, a coolant supply unit that supplies a coolant for cooling the fuel cell unit, and an exhaust cooling unit that cools the exhaust gas from the fuel cell unit with the coolant.

The fuel cell power generation system disclosed herein can suppress the generation of white smoke in the exhaust.

FIG. 1 is a diagram showing an outline of the configuration of a fuel cell power generation system according to a first embodiment. FIG. 2 is a diagram showing an outline of the configuration of a fuel cell power generation system according to the second embodiment. FIG. 3 is a diagram showing an outline of the configuration of a fuel cell power generation system according to the third embodiment. FIG. 4 is a diagram showing an outline of the configuration of a fuel cell power generation system according to the fourth embodiment. FIG. 5 is a diagram showing an outline of the configuration of a fuel cell power generation system according to a fifth embodiment. FIG. 6 is a diagram showing an outline of the configuration of a fuel cell power generation system according to a sixth embodiment. FIG. 7 is a diagram showing an outline of the configuration of a fuel cell power generation system according to a seventh embodiment.

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

In addition, with regard to the description of the specification and drawings relating to each embodiment, components having substantially the same or corresponding functional configurations may be given the same reference numerals to avoid redundant explanation. Also, to facilitate understanding, the scale of each part in the drawings may differ from the actual scale.

First Embodiment
A fuel cell power generation system according to the first embodiment will be described below. 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 exhaust gas from the fuel cell unit with the coolant.

The fuel cell power generation system according to the 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 a fuel cell power generation system according to the first embodiment.

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.

The fuel cell power generation system 1 comprises a fuel cell section 10, a coolant supply section 20, and an exhaust cooling section 30.

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

The fuel cell stack 11 in the fuel cell section 10 generates heat when generating electricity. Coolant RF1 is supplied to the fuel cell section 10 from the 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.

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 many single cells are stacked.

The unit cell in the fuel cell stack 11, which is a solid polymer electrolyte fuel cell, includes a membrane electrode assembly (MEA) that includes 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, for example, a catalyst layer whose main component is carbon powder that supports a platinum-based metal catalyst (electrode catalyst), and a gas diffusion layer that is both breathable and electronically conductive. Furthermore, the unit cell includes a pair of separators that sandwich the membrane electrode assembly (MEA) from both sides.

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

The fuel cell stack 11 generates electricity by chemically reacting hydrogen SH and air SA supplied from the outside. 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 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.

The fuel cell section 10 is cooled by the coolant RF1 supplied from the coolant supply section 20. In the fuel cell section 10, the fuel cell stack 11 is cooled by the coolant RF2 that has undergone heat exchange with the coolant RF1 by the 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.

Heat exchanger 12 exchanges heat between cooling liquid RF1 and cooling liquid RF2. Heat exchanger 12 is equipped with a heat exchanger that exchanges heat between cooling liquid RF1 and cooling liquid RF2.

The fuel cell section 10 is supplied with coolant RF1c, which is coolant RF1 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.

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

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

In addition, the fuel cell section 10 may not include a heat exchanger 12 and the fuel cell stack 11 may be directly cooled by the coolant RF1.

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

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

[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.

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

Then, the cooling liquid RF1a that has exchanged heat with the exhaust EX in the exhaust cooling section 30 is discharged as cooling liquid RF1c whose temperature is higher than that of the cooling liquid RF1a. The cooling liquid RF1c is supplied to the fuel cell section 10.

In addition, exhaust EXa cooled by the cooling liquid RF1a is discharged from the exhaust cooling section 30. The exhaust EXa is mixed with and diluted by the air RA in the space in which the fuel cell section 10 is installed. The exhaust EXa diluted by the air RA is discharged to the outside as exhaust EXb.

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. Furthermore, according to the fuel cell power generation system of the first embodiment, the exhaust gas in the fuel cell section is cooled by a cooling liquid for cooling the fuel cell section, which eliminates the need to provide a separate cooling device for cooling the exhaust gas, thereby enabling the system to be made more compact.

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.

The fuel cell power generation system according to the second embodiment will be described with reference to the drawings. FIG. 2 is a diagram showing an outline of the configuration of 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 configuration common to fuel cell power generation system 1, the description of fuel cell power generation system 1 should be referred to and will not be repeated here. The same applies to the following embodiments.

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

[Exhaust 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 heater for boiler feed water, an absorption chiller, or a binary power generation device.

The exhaust heat recovery unit 40 discharges the cooling liquid RF1a supplied from the cooling liquid supply unit 20 to the exhaust cooling unit 30 as cooling liquid RF1b. The exhaust heat recovery unit 40 may, for example, heat or cool the cooling liquid RF1a while discharging the supplied cooling liquid RF1a as cooling liquid RF1b.

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

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

In addition to the 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, allowing for efficient use of energy.

Third Embodiment
A fuel cell power generation system according to a 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.

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

The fuel cell power generation system 3 further includes an auxiliary unit 70 in addition to the fuel cell power generation system 2.

[Auxiliary machinery section 70]
The auxiliary section 70 includes auxiliary devices 71 for operating the fuel cell section 10. The auxiliary devices 71 include, for example, an air compressor and a boost converter. The auxiliary devices 71 in the auxiliary section 70 are cooled by the cooling liquid RF21 that has exchanged heat with the cooling liquid RF1. The auxiliary section 70 includes a heat exchanger 72 that exchanges heat between the cooling liquid RF1 and the cooling liquid RF21.

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

In addition, the auxiliary section 70 may not be provided with a heat exchanger 72, and the auxiliary 71 may be directly cooled by the coolant RF1.

The fuel cell power generation system according to the third embodiment has the same effects as the fuel cell power generation system according to the second embodiment, and can also cool the auxiliary parts for operating the fuel cell section.

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 can be different.

Fourth Embodiment
A fuel cell power generation system according to a 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.

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

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

[Exhaust Heating Section 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.

The high-temperature cooling liquid 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 cooling liquid RF1d is heated. When the exhaust EXa1 is heated, the relative humidity decreases, which further suppresses the generation of white smoke.

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

The fuel cell power generation system according to the fourth embodiment has the same effects as the fuel cell power generation system according to the third embodiment, and further suppresses the generation of white smoke.

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 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.

The fuel cell power generation system according to the 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 a fuel cell power generation system according to the fifth embodiment.

The fuel cell power generation system 5 is equipped with an exhaust heat recovery section 45 instead of the exhaust heat recovery section 40 in the fuel cell power generation system 3.

[Exhaust 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.

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

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.

The fuel cell power generation system according to the fifth embodiment has the same effects as the fuel cell power generation system according to the third embodiment, and can efficiently cool the fuel cell section, exhaust cooling section, and auxiliary section. The fuel cell power generation system according to the fifth embodiment can efficiently recover exhaust heat from the fuel cell section, exhaust cooling section, and auxiliary section.

Although not shown in FIG. 5, an adjustment mechanism may be provided for adjusting the flow distribution ratio of the cooling liquid RF1b1, the cooling liquid RF1b2, and the cooling liquid RF1b3. Specific examples of the adjustment mechanism include an adjustment valve, an orifice, and a flow controller.

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 from the fuel cell unit for cooling.

The fuel cell power generation system according to the 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 a fuel cell power generation system according to the sixth embodiment.

The fuel cell power generation system 6 includes an exhaust cooling section 130 in place 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.

[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 10 .

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

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

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 portion of the coolant RF3 is discharged as wastewater WW.

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

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

The exhaust heat recovery unit 140 discharges the cooling liquid RF3a supplied from the cooling liquid supply unit 120 to the exhaust cooling unit 130 as cooling liquid RF3b. The exhaust heat recovery unit 140 may, for example, heat or cool the cooling liquid RF3a while discharging the supplied cooling liquid RF3a as cooling liquid RF3b.

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

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. Furthermore, 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.

Seventh embodiment
<Fuel cell power generation system>
A fuel cell power generation system according to a seventh embodiment will be described below. The fuel cell power generation system according to the seventh embodiment cools exhaust gas from a plurality of fuel cell units.

The fuel cell power generation system according to the 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 a fuel cell power generation system according to the seventh embodiment.

The fuel cell power generation system 7 includes two fuel cell sections 10. The exhaust cooling section 130 cools the exhaust gas 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.

In the example of FIG. 7, an example is described in which the fuel cell power generation system according to the sixth embodiment is provided with multiple fuel cell units 10, but the fuel cell power generation systems according to the first to fifth embodiments may also be provided with multiple fuel cell units.

In the fuel cell power generation system according to the seventh embodiment, in addition to the effects of the fuel cell power generation systems according to the first to sixth embodiments, the output of the fuel cell power generation system can be improved by providing multiple fuel cell units.

Although the embodiments have been described above, they are presented as examples, and the present invention is not limited to the above embodiments. The above embodiments 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 variations 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.

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 section 71 Auxiliary 72 Heat exchanger CW Condensed water EX, EXa, EXa1, EXb, EXb1 Exhaust RA Air RF1, RF3 Coolant SA Air SH Hydrogen

Claims (12)

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 section that cools a mixture of a first exhaust gas discharged from a hydrogen electrode side in a fuel cell stack included in the fuel cell section and a second exhaust gas discharged from an oxygen electrode side in the fuel cell stack using the cooling liquid;
Equipped with
Fuel cell power generation system. 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 . 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 . 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 . 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 . 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. 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. 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 a mixture of a first exhaust gas discharged from a hydrogen electrode side in a fuel cell stack included in the fuel cell unit and a second exhaust gas discharged from an oxygen electrode side in the fuel cell stack ;
a coolant supply unit for supplying 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. A fuel cell unit that generates electricity by chemically reacting hydrogen and oxygen;
a coolant supply unit for supplying a coolant;
an exhaust cooling section that sprays the cooling liquid directly onto a mixture of a first exhaust gas discharged from a hydrogen electrode side in a fuel cell stack provided in the fuel cell section and a second exhaust gas discharged from an oxygen electrode side in the fuel cell stack, thereby cooling the mixture;
Equipped with
Fuel cell power generation system. The cooling liquid includes condensed water obtained by cooling and condensing the exhaust gas.
The fuel cell power generation system according to claim 9. 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. 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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