WO2003032422A1

WO2003032422A1 - Fuel cell system, and fuel cell power generating method

Info

Publication number: WO2003032422A1
Application number: PCT/JP2002/010154
Authority: WO
Inventors: Yoshihiro Nishizuru; Akinari Nakamura; Tatsuo Nakayama
Original assignee: Matsushita Electric Industrial Co., Ltd.; Matsushita Seiko Co., Ltd.
Priority date: 2001-10-02
Filing date: 2002-09-30
Publication date: 2003-04-17
Also published as: JP2005108436A

Abstract

It has been impossible to fully bring out the function the fuel cell main body inherently has. A fuel cell system that is fed with fuel gas and an oxidant to effect power generation utilizing a fuel cell (1), comprising a temperature-humidity exchange type heat exchanger (16) having a temperature-humidity exchange surface formed of a polyelectrolytic film separating a chamber to which the oxidant fed is introduced from a chamber to which the oxidant discharged from the fuel cell (1) is introduced, to effect temperature and humidity exchange between the oxidant fed and the oxidant discharged from the fuel cell (1), wherein the impurities contained in the oxidant fed are adsorbed by the polyelectrolytic film during temperature and humidity exchange.

Description

Description Fuel cell system and fuel cell power generation method

The present invention relates to a fuel cell system and a fuel cell power generation method. Background art

First, the configuration of a conventional fuel cell system will be described with reference to FIG. 7, which is a configuration diagram of a conventional fuel cell system.

As shown in FIG. 7, the conventional fuel cell system includes a fuel cell 1 and a fuel processing device 2 ′ that reforms a raw material such as natural gas, generates hydrogen-rich gas, and supplies the gas to the fuel cell 1. A burner 3 for raising the temperature of the fuel processor 2 to a temperature required for the reforming reaction, a fuel humidifier 4 for humidifying the fuel gas supplied to the fuel cell 1, and a fuel gas discharged from the fuel cell 1. A fuel-side water recovery unit 5 that recovers the contained water vapor, an air supply unit 6 that supplies oxidant air to the fuel cell 1, and an oxidization-side humidifier 7 'that humidifies the supply air by supplying water to the heating iron plate. An oxidizing water recovery unit 8 for recovering water vapor contained in air discharged from the fuel cell 1, a fuel-side water recovery unit 5, and a water storage tank 9 for storing water recovered by the oxidizing-side water recovery unit 8. The fuel water pump 10 that sends the recovered water to the fuel humidifier 4 and the acid And a side humidifier 7 'oxidation side water pump 1 1 to be sent to the'.

Further, a cooling pipe 12 for sending water to the fuel cell 1 for cooling, a cooling pump 13 for circulating water in the pipe, and a cooling radiator 14 for releasing heat generated in the fuel cell 1 to the outside And Next, the operation of the conventional fuel cell system will be described.

The fuel gas converted into a hydrogen-rich gas by the fuel processor 2 ′ is humidified by the fuel humidifier 4 using water supplied from the water storage tank 9 by the fuel water pump 10, and the fuel cell 1 Sent to. The fuel gas discharged from the fuel cell 1 and not used for power generation is dehumidified by the fuel-side water collector 5, and then released to the atmosphere.

On the other hand, the air used for the oxidizing agent is sent to the oxidizing humidifier T by the air supply device 6 and humidified by the water supplied from the water storage tank 9 by the oxidizing water pump 11 ′ to the fuel cell 1 Sent to. The air not used for power generation discharged from the fuel cell 1 is dehumidified by the oxidizing water recovery unit 8 and then released to the atmosphere.

In addition, in order to keep the temperature of the fuel cell 1 that generates power constant, water is circulated by the cooling pump 13 through the cooling pipe 12, and the heat generated by the fuel cell 1 is cooled by the cooling radiator 14. Release to

In addition, there is a fuel cell system provided with an impurity gas removing means for removing impurity gas contained in the air, which causes a decrease in fuel cell performance (for example, see Patent Document 1 below).

[Patent Document 1]

JP-A-8-138703

However, as described above, the air supplied to the fuel cell system as an oxidizing agent is composed of fine particles and ions (such as sodium ions in seawater in coastal areas) in the air. May contain many impurities.

More specifically, (1) Dust, dust, and grease block the flow path (these large particles may damage MEA (membrane electrodease mbly, membrane / electrode assembly)) ), ( 2) organic molecules such as C 0 ₂ is poisoned catalyst, (3) metallic ions are traps that reduce the ionic conductivity, the inventors are not noticed. Disclosure of the invention

The inventor of the present invention has conceived that the above-mentioned impurities induce poisoning of the polymer film which leads to deterioration of the performance of the fuel cell main body. We thought that we could bring out the performance that we had.

An object of the present invention is to provide a fuel cell system and a fuel cell power generation method that can sufficiently bring out the inherent performance of a fuel cell body in consideration of the above-described conventional problems. is there.

A first aspect of the present invention is a fuel cell system including a fuel cell that is supplied with a fuel gas and an oxidant to generate power,

A room into which the supplied oxidant is introduced and an exhausted gas from the fuel cell for exchanging temperature and humidity between the supplied oxidant and the oxidant discharged from the fuel cell. A humidity-exchange type heat exchanger having a temperature-humidity exchange surface formed of a predetermined ion exchange material that separates the room into which the oxidizing agent is introduced.

In the fuel cell system, the impurities contained in the supplied oxidant are adsorbed on the ion exchange material when the temperature and humidity are exchanged.

A second invention is the fuel cell system according to the first invention, wherein the ion exchange material is a polymer electrolyte membrane.

In a third aspect of the present invention, the temperature and humidity exchange surface is freely replaceable. 1 is a fuel cell system of the present invention.

The fourth invention is a fuel cell power generation method for generating power using a fuel cell by supplying a fuel gas and an oxidant,

A room into which the supplied oxidant is introduced and an exhausted gas from the fuel cell for performing temperature and humidity exchange between the supplied oxidant and the oxidant discharged from the fuel cell. Using a humidity exchange type heat exchanger having a temperature / humidity exchange surface formed of a predetermined ion exchange material that separates the room into which the oxidant is introduced, impurities contained in the supplied oxidant are removed. When the temperature and humidity are exchanged, the ions adsorbed on the ion exchange material

-This is a fuel cell power generation method. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a configuration diagram of a fuel cell system in Embodiment 1 related to the present invention.

FIG. 2 is a configuration diagram of the humidifier 7 in Embodiment 1 related to the present invention.

FIG. 3 is a configuration diagram of a humidifier in Embodiment 2 related to the present invention.

FIG. 4 is a configuration diagram of a fuel cell system according to Embodiment 3 of the present invention.

FIG. 5 is a configuration diagram of a temperature / humidity exchange type heat exchanger 16 according to Embodiment 3 of the present invention.

FIG. 6 is a configuration diagram of a temperature / humidity exchange type heat exchanger according to Embodiment 4 of the present invention.

FIG. 7 is a configuration diagram of a conventional fuel cell system. (Explanation of code)

. Fuel cell

2 Reformer

3 Norner

4 Fuel humidifier

5 Fuel side water recovery unit

6

7 Oxidation side humidifier

8 Oxidation side water recovery unit

9

1 0 Fuel side water pump

1 1 Collected water supply pump

1 2 Cooling piping

1 3 Cooling pump

1 4 Cooling radiator

1 5 Heat sink

1 6 Heat and humidity exchange type heat exchanger

1 7 Temperature and humidity exchange unit

1 8 Polyelectrolyte cutout BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present embodiment will be described with reference to the drawings.

(Embodiment 1)

First, a fuel cell system according to Embodiment 1 related to the present invention The configuration of the fuel cell system according to the present embodiment will be described with reference to FIG. 1 which is a configuration diagram of the fuel cell system and FIG. 2 which is a configuration diagram of the humidifier 7 in the first embodiment related to the present invention. I do.

The fuel cell system according to the present embodiment includes a fuel cell 1 that generates power using a fuel gas and an oxidizing gas, a reformer 2 that reforms a raw material to generate a hydrogen-rich reformed gas, An air supply device 6 for supplying the air to the fuel cell 1, a humidifier 7 (see FIG. 2) for humidifying the supply air supplied by the air supply device 6, and an air and fuel gas discharged from the fuel cell. A heat dissipator 15 for condensing and recovering the water vapor contained therein, a water storage tank 9 for storing the recovered water collected by the heat dissipator 15, and a humidifier 7 stored in the stock water tank 9. The recovered water supply pump 11 for supplying the recovered water, the cooling pipe 12 for cooling the fuel cell 1 by circulating water between the fuel cell 1 and the heat sink 15, and the cooling pump 1 3 It is composed of

Of course, as will be described in detail later, the fuel cell system according to the present embodiment raises the temperature of the recovered water by a heater or the like, and humidifies and purifies the supply air by passing the heated water through the recovered water. A major feature is that it is equipped with a humidifier 7 that operates.

Among the means described above, the means having the same functions as those of the conventional fuel cell system (see FIG. 7) are given the same reference numerals, and those functions are the same as those of the conventional fuel cell system. According to the function of.

In the present embodiment, the cooling pipe 12, the cooling pump 13, and the heat radiator 15 constitute a cooling circuit, and the heat radiator 15 is a cooling radiator, an oxidizing side. It integrates a water recovery unit and a fuel-side water recovery unit. Next, the operation of the fuel cell system according to the present embodiment will be described. Note that while describing the operation of the fuel cell system of the present embodiment, an embodiment of a fuel cell power generation method related to the present invention will also be described. (The same applies to the following embodiment).

The reformer 2 reforms a raw material (for example, natural gas) to generate a hydrogen-rich gas, which is then supplied to the fuel cell 1. On the other hand, the air supplied to the fuel cell 1 by the air supply device 3 as the oxidizing gas is humidified by the humidifier 7 and supplied to the fuel cell 1 as described later. The temperature of the fuel and air discharged without being consumed from the fuel cell 1 is lowered by the heat rejector 15, and the water vapor contained therein is recovered and then released to the atmosphere. The recovered water is stored in a water storage tank 9 and then supplied to a humidifier 7 by a recovered water supply pump 11 to be stored and used for humidification. Water for cooling the fuel cell 1 is circulated through a cooling pipe 12 by a cooling pump 13, and the heat generated in the fuel cell 1 is released to the outside by exchanging heat with outside air by a heat exchanger 15. Put out.

The humidifier 7 (see FIG. 2) in the present embodiment raises the temperature of the recovered water supplied and stored by a recovered water supply pump 11 by a heater or the like inside the humidifier 7 and stores the heated recovered water inside the humidifier 7 The supply air is humidified by being fed through a hole provided below the surface of the collected water (bubbling). (The oxidizing agent is used when passing the recovered water that has been heated. Humidification is also performed).

When the supply air is humidified, it passes through the recovered water, and impurities and ions contained in the supply air are purified by being taken into the recovered water. It is possible to reduce ions and the like, and it is possible to operate the fuel cell 1 without deteriorating its inherent performance (especially, suppressing flow path blockage due to dust, dirt, and grease). It becomes possible).

In the above-described embodiment, the cooling radiator is described as being integrated with the oxidizing-side water collector and the fuel-side water collecting unit. Either or both of them may be used alone, and there is no difference in the operation and effect.

(Embodiment 2)

Next, the configuration and operation of the fuel cell system according to the present embodiment will be described with reference to FIG. 3, which is a configuration diagram of the humidifier in the second embodiment related to the present invention. '

The configuration and operation of the fuel cell system according to the present embodiment are similar to the configuration and operation of the fuel cell system according to the first embodiment described above.

However, in the humidifier in the present embodiment, the supply air inside the humidifier is heated by a heater or the like, and the recovered water supplied by the recovered water supply pump 11 (see FIG. 1) is supplied to the heated supply air. Humidification of the supplied air by spraying in the form of an appropriate fog (mist) (The oxidizer supplied is also humidified when the recovered water is sprayed by raising the temperature. ).

When the supply air is humidified, by spraying the mist-like recovery water into the supply air, impurities and ions contained in the supply air are taken into the recovery water, and moisture not used for humidification is condensed again. By removing impurities and ions at the time of supply, the supply air is purified and impurities and ions in the supply air supplied to the fuel cell 1 can be reduced, which lowers the inherent performance of the fuel cell 1. It is possible to operate without causing the catalyst (especially, poisoning of the catalyst by organic molecules such as co ₂ can be suppressed).

(Embodiment 3)

First, FIG. 4 is a configuration diagram of the fuel cell system according to the third embodiment of the present invention, and FIG. 5 is a configuration diagram of a temperature-humidity exchange type heat exchanger 16 according to the third embodiment of the present invention. The configuration of the fuel cell system according to the present embodiment will be described with reference to FIG.

The fuel cell system according to the present embodiment uses fuel gas and oxidizing gas. A fuel cell 1 for generating electric power by generating electricity, a reformer 2 for reforming a raw material to generate a hydrogen-rich reformed gas, an air supply device 6 for supplying air as an oxidant to the fuel cell 1, and the air A temperature-humidity exchange type heat exchanger that exchanges temperature and humidity between the supply air supplied by the supply device 6 and the exhaust air from the fuel cell 1

(It may be simply referred to as a humidity exchange type heat exchanger) 16 (see Fig. 5) and condensate water vapor contained in air and fuel gas discharged from the temperature and humidity exchange type heat exchanger 16 Heat collector 15 for collecting and recovering water, a water storage tank 9 for storing the recovered water collected by the heat sink 15, and a fuel cell by circulating water between the fuel cell 1 and the heat sink 15. It is composed of a cooling pipe 12 for cooling 1 and a cooling pump 13.

Of course, as will be described in detail later, the fuel cell system according to the present embodiment performs humidification of supply air and dehumidification of discharge air simultaneously by exchanging temperature and humidity between supply air and discharge air. In addition, a temperature / humidity exchange type heat exchanger 16 that purifies by introducing impurities contained in the supply air into a polymer electrolyte membrane such as Nafion Pore Select (both are trade names) is provided. The point is a big feature.

The fuel cell system according to the first embodiment described above among the above-described units.

Means having the same functions as those of FIG. 1 are denoted by the same reference numerals, and those functions are in accordance with the functions of each means of the fuel cell system according to the first embodiment.

In the present embodiment, the cooling pipe 12, the cooling pump 13, and the heat radiator 15 constitute a cooling circuit, and the heat radiator 15 is a cooling radiator, an oxidizing side. It integrates a water recovery unit and a fuel-side water recovery unit.

Next, the operation of the fuel cell system according to the present embodiment will be described. The reformer 2 reforms a raw material (eg, natural gas) to generate a hydrogen-rich gas, and then supplies the gas to the fuel cell 1. On the other hand, in the present embodiment, the air supplied to the fuel cell 1 by the air supply device 6 as the oxidizing gas is different from the exhaust air discharged from the fuel cell 1 by the temperature / humidity exchange type heat exchanger 16. By exchanging the temperature and humidity between the two, the humidification of the supply air and the dehumidification of the discharge air are performed at the same time, and then the fuel is supplied to the fuel cell 1.

Exhaust air discharged without being consumed from the fuel cell 1 and dehumidified by the temperature / humidity exchange heat exchanger 16 and exhausted fuel not consumed by the fuel cell 1 are cooled by the exhaust heatr 15 After the water vapor contained inside is recovered, it is released to the atmosphere. The recovered water collected is stored in a water storage tank 9 and then supplied to a reformer 2 by a recovered water supply pump 11 to be used for reforming. Water for cooling the fuel cell 1 is circulated through a cooling pipe 12 by a cooling pump 13, and the heat generated by the fuel cell 1 is released to the outside by exchanging heat with the outside air at a heat exchanger 15. I do.

The temperature-humidity exchange heat exchanger 16 uses the polymer electrolyte membrane used for the fuel cell 1 on the temperature-humidity exchange surface to humidify the supply air without using any power and supply Purification can be achieved by taking in impurities such as ions contained in the air into the polymer electrolyte membrane (in particular, a reduction in ion conductivity due to trapping of metal ions can be suppressed). Thus, the fuel cell 1 can be operated without deteriorating its inherent performance.

In the above-described embodiment, the cooling radiator is described as being integrated with the oxidizing-side water collector and the fuel-side water collecting unit. However, either or both of them may be used alone. It may be composed, and there is no difference in the effects.

(Embodiment 4)

Next, a temperature-humidity exchange type heat exchanger according to Embodiment 4 of the present invention. The configuration and operation of the fuel cell system according to the present embodiment will be described with reference to FIG.

The configuration and operation of the fuel cell system according to the present embodiment are similar to the configuration and operation of the fuel cell system according to the third embodiment described above.

However, the temperature / humidity exchange type heat exchanger in the present embodiment includes a temperature / humidity exchange unit 17 and a polymer electrolyte membrane unit 18. The temperature / humidity exchange unit 17 has a structure in which the polymer electrolyte membrane unit 18 can be removed by sliding, so that the exchange of the polymer electrolyte membrane unit 18 can be performed easily.

If the operation of the fuel cell system is continued and humidification is performed by the temperature-humidity exchange type heat exchanger and the adsorption and removal of ions and the like contained in the supply air are continued, the ions in the supply air will be adsorbed in the polymer electrolyte membrane. However, the temperature and humidity exchange performance of the polymer electrolyte membrane decreases.

In the conventional temperature-humidity exchange heat exchanger, if the polymer electrolyte membrane deteriorates, the temperature-humidity exchange performance cannot be restored unless the entire temperature-humidity exchange heat exchanger is replaced.

In the temperature-humidity exchange type heat exchanger according to the present embodiment, even when the polymer electrolyte membrane is deteriorated due to the continuous adsorption and removal of ions and the like contained in the supply air by the polymer electrolyte membrane butt 18. By simply replacing the polymer electrolyte cut 18, the original temperature and humidity exchange performance can be restored. This eliminates the need to replace the temperature and humidity exchange type heat exchanger when the polymer electrolyte membrane has deteriorated, and at the same time reduces maintenance costs due to replacing only the polymer electrolyte unit 18. In other words, reduction can be achieved.

In the above-described embodiment, the polymer electrolyte unit 18 is replaced by sliding, but only the polymer electrolyte unit is replaced. Any structure may be used as long as the structure can be replaced, and no difference is produced in the operation and effect. In the above, the first to fourth embodiments have been described in detail.

Although the impurity removing means related to the present invention is a means including a humidifier in the above-described embodiment, the present invention is not limited to this. In other words, the impurity removing means is included in the gas discharged from the fuel cell. Any means may be used as the means for removing impurities contained in the supplied oxidant by using the recovered water from which the water vapor is recovered.

In short, the present invention relates to a fuel cell system which is supplied with a fuel gas and an oxidizing agent (air) to generate electric power using a fuel cell, wherein the gas discharged from the fuel cell (discharged from the fuel cell) This is a fuel cell system equipped with an impurity removing unit that removes impurities contained in the supplied oxidant by using recovered water from which steam contained in air and fuel gas is recovered.

Further, the present invention relates to a fuel cell system which is supplied with a fuel gas and an oxidizing agent (air) to generate electric power using a fuel cell, wherein the oxidizing agent discharged from the fuel cell is used. This is a fuel cell system provided with impurity removing means for removing impurities contained in the supplied oxidizing agent.

Further, the ion exchange material is a polymer electrolyte membrane in the present embodiment described above, but is not limited thereto, and may be, for example, an ion exchange resin.

Of course, the oxidizing agent according to the present invention may be humidified while removing impurities contained therein.

Therefore, according to the present invention, for example, while humidifying the supply air, impurities, ions, and the like contained in the supply air are removed, and the performance inherent in the fuel cell can be sufficiently obtained.

In addition, a temperature-humidity exchange heat exchanger is used for temperature adjustment and humidification of the supply air. By using a polymer electrolyte membrane for the temperature and humidity exchange surface, it is possible to achieve temperature control and humidification of the supply air using the heat and steam contained in the air discharged from the fuel cell without using any power. At the same time, ions contained in the supply air can be adsorbed and removed, and the inherent performance of the fuel cell can be fully exploited.

Furthermore, in the temperature / humidity exchange heat exchanger, the polymer electrolyte membrane used for the temperature / humidity exchange surface is unitized to have a shape that can be removed from the temperature / humidity exchange heat exchanger, so that it is included in the supply air. By absorbing and removing ions and the like, the deteriorated polymer electrolyte unit can be easily replaced, and even if the temperature / humidity exchange performance deteriorates, the performance can be easily recovered at low cost.

Next, the invention which was invented by the inventor and which is related to the above-mentioned invention will be described.

The first invention is a fuel cell system including a fuel cell that is supplied with a fuel gas and an oxidizing agent to generate power,

A room into which the supplied oxidant is introduced and an exhausted gas from the fuel cell for performing temperature and humidity exchange between the supplied oxidant and the oxidant discharged from the fuel cell. A humidity-exchange type heat exchanger having a temperature-humidity exchange surface formed of a predetermined ion exchange material that separates the room into which the oxidizing agent is introduced.

The impurities contained in the supplied oxidizing agent can be obtained by a fuel cell system that is adsorbed on the ion exchange material when the temperature and humidity are exchanged.

In a third aspect, the temperature / humidity exchange surface is freely replaceable. It is a fuel cell system of the invention.

A fourth invention is a fuel cell power generation method for performing power generation using a fuel cell by supplying a fuel gas and an oxidant,

A room into which the supplied oxidant is introduced and an exhausted gas from the fuel cell for performing temperature and humidity exchange between the supplied oxidant and the oxidant discharged from the fuel cell. Using a humidity exchange type heat exchanger having a temperature / humidity exchange surface formed of a predetermined ion exchange material that separates the room into which the oxidant is introduced, impurities contained in the supplied oxidant are removed. A fuel cell power generation method comprising a step of adsorbing to the ion exchange material when the temperature and humidity are exchanged.

A fifth invention is a fuel cell system including a fuel cell that is supplied with a fuel gas and an oxidant to generate power,

A fuel cell system comprising an impurity removing means for removing impurities contained in the supplied oxidant by using recovered water in which water vapor contained in gas discharged from the fuel cell is recovered. '

A sixth aspect of the present invention is the fuel cell system according to the fifth aspect, wherein using the recovered water means passing the recovered water through the supplied oxidizing agent.

In a seventh aspect, the impurity removing means includes: a storage portion for storing the recovered water; a hole provided in a portion below the surface of the stored recovered water, for feeding the oxidizing agent; A fuel cell system according to a sixth aspect of the present invention, comprising a heater for raising the temperature of the recovered water.

An eighth invention is the fuel cell system according to the fifth invention, wherein the use of the recovered water is to inject the recovered water into the supplied oxidant. The fuel cell according to the eighth aspect of the present invention includes: a spray section for spraying the recovered water; and a heater for heating the oxidant. Pond system.

A tenth invention is a fuel cell power generation method for performing power generation using a fuel cell by supplying a fuel gas and an oxidizing agent,

A fuel cell power generation method comprising a step of removing impurities contained in the supplied oxidant by using recovered water in which water vapor contained in gas discharged from the fuel cell is recovered.

The entire disclosure of the above-mentioned documents is incorporated by reference (referred to as such) here. Industrial applicability

As is apparent from the above description, the present invention has an advantage that the inherent performance of the fuel cell body can be sufficiently brought out.

Claims

Sought

1. A fuel cell system including a fuel cell that is supplied with a fuel gas and an oxidant to generate power,

A room in which the supplied oxidant is introduced and an oxidation discharged from the fuel cell for exchanging temperature and humidity between the supplied oxidant and the oxidant discharged from the fuel cell. A humidity-exchange type heat exchanger having a temperature-humidity exchange surface formed of a predetermined ion exchange material that separates the room into which the agent is introduced,

The fuel cell system according to claim 1, wherein the impurities contained in the supplied oxidant are adsorbed on the ion exchange material when the temperature and humidity are exchanged.

2. The fuel cell system according to claim 1, wherein the ion exchange material is a polymer electrolyte membrane.

3. The fuel cell system according to claim 1, wherein the temperature and humidity exchange surface is freely replaceable.

4. A fuel cell power generation method in which fuel gas and an oxidant are supplied to generate power using a fuel cell,

A room in which the supplied oxidant is introduced and an oxidation discharged from the fuel cell for exchanging temperature and humidity between the supplied oxidant and the oxidant discharged from the fuel cell. Using a humidity exchange type heat exchanger having a temperature / humidity exchange surface formed of a predetermined ion exchange material that separates the room into which the agent is introduced, impurities contained in the supplied oxidant are removed by the temperature And a step of adsorbing the ion exchange material when the humidity is exchanged.