JP2003017098A - Fuel cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make hot water supply possible in a fuel cell system humidifying raw gas by the combustion of exhaust gas from a hydrogen electrode. SOLUTION: A water circulation passage 65 is installed in the fuel cell system. A first heat exchanger 71 and a second heat exchanger 74 are connected to the water circulation passage 65. Exhaust heat of a fuel cell 10 is added to heat transfer water in the first heat exchanger 71. Combustion gas obtained by combustion of exhaust gas from a hydrogen electrode in a combustor 51 is introduced into the second heat exchanger 74. Combustion heat of the exhaust gas from the hydrogen electrode is added to heat transfer water in the second heat exchanger 74. Heat transfer water heated with the first heat exchanger 71 and the second heat exchanger 74 is stored in a hot water storage tank as hot water. Combustion gas heat radiated with the second heat exchanger 74 is supplied to a gas humidifier 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell system, and more particularly to a system for performing both power generation and hot water supply by exhaust heat.

[0002]

2. Description of the Related Art Conventionally, as disclosed in US Pat. No. 6,0079,31, a fuel cell system in which a fuel cell and a reformer are combined is known. In this fuel cell system, a reformer reforms a raw material gas to produce a fuel gas, and the obtained fuel gas is supplied to a gas passage on the hydrogen electrode side of the fuel cell. Further, the hydrogen electrode exhaust gas discharged from the gas passage on the hydrogen electrode side is burned, and the combustion heat heats water to generate water vapor. This steam is mixed with the raw material gas and sent to the reforming device, where it is used for reforming the raw material gas.

[0003]

However, the above fuel cell system is mainly intended for in-vehicle use, and no consideration has been given to hot water supply using exhaust heat. On the other hand, when the above fuel cell system is installed in a house or building and used as an individual distributed power generation system, the energy efficiency of the entire system is improved by using a cogeneration system that uses hot water to supply hot water. It is required to raise it.

The present invention has been made in view of the above points, and an object of the present invention is to enable hot water supply in the above fuel cell system in which the hydrogen electrode exhaust gas is burned to humidify the raw material gas and the like. Especially.

[0005]

A first solution provided by the present invention is a reformer (30) for a fuel cell system, which reforms a supplied raw material gas to produce a fuel gas.
And a fuel cell (10) in which the oxidant gas is supplied to the gas passage (11) on the oxygen electrode side and the fuel gas produced by the reformer (30) is supplied to the gas passage (12) on the hydrogen electrode side. ), A combustor (51) for combusting the hydrogen electrode exhaust gas discharged from the gas passage (12) on the hydrogen electrode side of the fuel cell (10) to generate combustion gas, and for generating hot water for hot water supply. A heat recovery means (70) for recovering heat from the combustion gas, and at least the raw material using the steam separated by the steam permeable membrane (41) from the combustion gas recovered by the heat recovery means (70). And a gas humidifying means (45) for humidifying the gas.

A second means for solving the problems of the present invention is directed to a fuel cell system, and a reformer (30) for reforming a supplied raw material gas to produce a fuel gas, and an oxidant gas containing oxygen. The fuel gas supplied to the gas passage (11) on the electrode side and produced in the reformer (30) is the gas passage (1) on the hydrogen electrode side.
2) the fuel cell (10) supplied to the above fuel cell (1)
Combustion unit (51) for combusting the hydrogen electrode exhaust gas discharged from the gas passage (12) on the hydrogen electrode side of (0) to generate combustion gas.
A gas humidifying means (45) for humidifying at least the raw material gas by utilizing the steam separated from the combustion gas by the steam permeable membrane (41), and the reforming device for generating hot water for hot water supply ( Heat recovery means (7)
0) and.

The third means for solving the problems by the present invention is the above-mentioned second means, wherein the heat recovery means (70) also includes combustion gas sent from the combustion section (51) to the gas humidification means (45). It is configured to recover heat.

A fourth solution means taken by the present invention is, in the first or second solution means, the heat recovery means so that the temperature of the combustion gas sent to the gas humidification means (45) becomes a predetermined value. The (70) is provided with an adjusting means (91) for adjusting the amount of heat recovered from the combustion gas.

A fifth solution provided by the present invention is the reformer (30) according to the second or third solution described above, wherein the reformer (33), the shift converter (34), and the CO remover. The heat recovery means (70) is configured so as to produce a fuel gas by circulating the gas in the order of (35), and the heat recovery means (70) is the reformer (33) or exits the reformer (33) and is the transformer. While being configured to recover heat from the gas sent to (34), the amount of heat recovered by the heat recovery means (70) is adjusted so that the temperature of the gas flowing into the transformer (34) becomes a predetermined value. The adjusting means (92) is provided.

A sixth solution provided by the present invention is the above-mentioned second or third solution, wherein the reformer (30) comprises a reformer (33), a shift converter (34) and a CO remover. The heat recovery circuit is configured so as to produce the fuel gas by circulating the gas in the order of (35), and the heat recovery circuit outputs the shift converter (34) or the shift converter (34) to the CO remover (35). The heat recovery means (70) is configured to recover heat from the sent gas and adjusts the amount of heat recovered by the heat recovery means (70) so that the temperature of the gas flowing into the CO remover (35) becomes a predetermined value. (92) is provided.

A seventh means for solving the problems according to the present invention is the reformer (30) according to the second or third means, wherein the reformer (33), the shift converter (34), and the CO remover. The gas is circulated in the order of (35) to produce the fuel gas, and the heat recovery circuit includes the CO remover (35) or the CO remover (35) to the fuel cell (10). The heat recovery means (70) is configured to recover heat from the sent fuel gas, and adjusts the amount of heat recovered by the heat recovery means (70) so that the temperature of the fuel gas flowing into the fuel cell (10) becomes a predetermined value. Means (92)
It is equipped with.

An eighth solution means provided by the present invention is the heat recovery means (70) according to the first or second solution means.
The fuel cell (10) is also configured to recover heat.

A ninth means for solving the problems according to the present invention is that, in the first or the third means, the oxygen electrode exhaust gas is discharged from a gas passage (11) on the oxygen electrode side of the fuel cell (10). The heat recovery means (70) is configured to heat the air or the oxygen electrode exhaust gas by the exhaust heat of the reforming device (30) and supply it to the combustion section (51).

-Operation- In the first and second solving means, the reformer (30) reforms the raw material gas to produce hydrogen-based fuel gas. The obtained fuel gas is supplied to the gas passage (12) on the hydrogen electrode side of the fuel cell (10). Further, oxygen-containing air or the like is supplied as an oxidant gas to the gas passage (11) on the oxygen electrode side of the fuel cell (10). In the fuel cell (10), a cell reaction that oxidizes hydrogen in the fuel gas is performed. Hydrogen gas exhaust gas containing unreacted hydrogen is discharged from the gas passage (12) on the hydrogen electrode side. This hydrogen electrode exhaust gas is sent to the combustion section (51).

In the combustion part (51), hydrogen in the hydrogen electrode exhaust gas is burned to generate high temperature combustion gas. This combustion gas contains water vapor generated by the combustion of hydrogen. Water vapor in the combustion gas passes through the water vapor permeable membrane (41) in the gas humidifying means (45) and is separated from the combustion gas. The gas humidifying means (45) uses the steam separated from the combustion gas to humidify at least the raw material gas. Therefore, the raw material gas containing steam is supplied to the reformer (30), and this steam is used for reforming the raw material gas.

In the first solving means, the heat recovery means (70) recovers the exhaust heat from the combustion gas generated in the combustion section (51). The heat recovery by the heat recovery means (70) is performed to obtain hot water for hot water supply. The heat recovery means (70) exchanges heat between the combustion gas and water to generate hot water, or exchanges heat between the heat medium heated by the combustion gas and water to generate hot water. In the present solution means, the combustion gas after heat recovery by the heat recovery means (70) is sent to the gas humidification means (45). That is, the combustion gas whose temperature has been lowered due to heat recovery is supplied to the gas humidifying means (45).

In the second solving means, the heat recovery means (70) recovers the exhaust heat from the reformer (30). The heat recovery by the heat recovery means (70) is performed to obtain hot water for hot water supply. The heat recovery means (70) is, for example, a reformer (3
The gas flowing through (0) and water are heat-exchanged to generate hot water,
Alternatively, the heat medium heated by the exhaust heat of the reformer (30) and water are heat-exchanged to generate hot water.

In the third means, the reformer (30)
The heat recovery means (70) recovers exhaust heat not only from the exhaust gas but also from the combustion gas generated in the combustion section (51). Heat recovery means (7
In 0), for example, the combustion gas and water are heat-exchanged to generate hot water, or the heat medium heated by the combustion gas and water are heat-exchanged to generate hot water. In the present solution means, the combustion gas after heat recovery by the heat recovery means (70) is sent to the gas humidification means (45). That is, the combustion gas whose temperature has been lowered due to heat recovery is supplied to the gas humidifying means (45).

In the above-mentioned fourth solution means, the adjusting means (91)
Adjusts the amount of heat recovered from the combustion gas by the heat recovery means (70). For example, when the heat recovery means (70) is configured to recover heat from the combustion gas by the circulating heat medium, the adjusting means (91) changes the recovered heat amount by increasing or decreasing the circulation amount of the heat medium. . The adjustment of the amount of recovered heat by the adjusting means (91) is performed so that the temperature of the combustion gas sent to the gas humidifying means (45) becomes a predetermined value.

In the fifth, sixth, and seventh means for solving the problems, in the reformer (30), the reformer (33), the transformer (34),
Gas flows in the order of the CO remover (35). Reformer (30)
The raw material gas supplied to is introduced into the reformer (33).
In the reformer (33), hydrogen (H ₂ ) is produced from the raw material gas by a steam reforming reaction or the like. The gas emitted from the reformer (33) is sent to the shift converter (34). In the transformer (34),
Hydrogen is produced from carbon monoxide (CO) and H ₂ O by the shift reaction. The gas emitted from the shift converter (34) is sent to the CO remover (35). In the CO remover (35), carbon monoxide in the gas is oxidized to carbon dioxide (CO ₂ ). Then, the gas emitted from the CO remover (35) is supplied to the fuel cell (10) as fuel gas.

Then, in the fifth solving means, the exhaust heat of the reformer (33) in the reformer (30) or the reformer (3
The exhaust heat of the gas sent from 3) to the transformer (34) is recovered by the heat recovery means (70). This heat recovery means (70)
The amount of exhaust heat recovered by is appropriately adjusted by the adjusting means (92). From the reformer (33) to the shift converter (34), the gas whose temperature is lowered by heat recovery by the heat recovery means (70) is sent. The amount of recovered heat is adjusted by the adjusting means (92) so that the temperature of the gas sent to the transformer (34) becomes a predetermined value.

In the sixth means, the reformer (30)
Heat from the transformer (34) in C, or C from the transformer (34)
The exhaust heat of the gas sent to the O remover (35) is recovered by the heat recovery means (70). The amount of exhaust heat recovered by the heat recovery means (70) is appropriately increased or decreased by the adjustment means (92). From the shift converter (34) to the CO remover (35), the gas whose temperature is lowered by heat recovery by the heat recovery means (70) is sent. The adjustment of the amount of heat recovered by the adjusting means (92) is performed so that the temperature of the gas sent to the CO remover (35) becomes a predetermined value.

In the seventh means, the reformer (30)
Exhaust heat of the CO remover (35) or the CO remover (3
The exhaust heat of the fuel gas sent from the 5) to the fuel cell (10)
It is recovered by the heat recovery means (70). The amount of exhaust heat recovered by the heat recovery means (70) is appropriately increased or decreased by the adjustment means (92). From the CO remover (35) to the fuel cell (10), the fuel gas whose temperature is lowered by heat recovery by the heat recovery means (70) is sent. The adjustment of the amount of recovered heat by the adjusting means (92) is performed so that the temperature of the fuel gas sent to the fuel cell (10) becomes a predetermined value.

In the eighth solution means, the heat recovery means (7
0) also recovers the exhaust heat of the fuel cell (10). The recovered exhaust heat of the fuel cell (10) is used to generate hot water for hot water supply.

In the ninth solution means, the heat recovery means (7
0) recovers the exhaust heat of the reformer (30) by using air or oxygen electrode exhaust gas. The air or the oxygen electrode exhaust gas heated by the exhaust heat of the reforming device (30) is supplied to the combustion section (51). Then, oxygen contained in the air or the oxygen electrode exhaust gas is used to burn hydrogen in the hydrogen electrode exhaust gas. The exhaust heat of the reformer (30) recovered by air and oxygen exhaust gas is
It is recovered as part of the exhaust heat of the combustion gas and is used to generate hot water for hot water supply.

[0026]

According to the present invention, since the heat recovery means (70) is provided in the fuel cell system, exhaust heat can be recovered from the combustion gas and the reformer (30), and further recovered. The waste heat can be used to generate hot water for hot water supply.

In particular, in the first and third solving means, the combustion gas whose temperature has been lowered due to the exhaust heat recovery by the heat recovery means (70) is supplied to the gas humidification means (45). Here, in the gas humidifying means (45), the combustion gas comes into contact with the water vapor permeable membrane (41) in order to separate the water vapor from the combustion gas. The water vapor permeable membrane (41) generally does not have such high heat resistance, and deteriorates when the high temperature combustion gas is brought into direct contact therewith. On the other hand, in these solving means, the combustion gas whose temperature has been lowered due to heat recovery is sent to the gas humidifying means (45). Therefore, according to these solving means, by lowering the temperature of the combustion gas supplied to the gas humidifying means (45), it is possible to prevent the water vapor permeable membrane (41) from being deteriorated by being exposed to high temperature. The reliability of the gas humidifying means (45) can be improved.

Further, in the above-mentioned fourth solution means, the temperature of the combustion gas supplied to the gas humidification means (45) is substantially changed by the adjustment means (91) changing the amount of heat recovered by the heat recovery means (70). It is kept at a predetermined value. Therefore, according to the present solution,
The temperature of the combustion gas supplied to the gas humidifying means (45) can be maintained at a temperature at which the deterioration of the water vapor permeable membrane (41) can be avoided, and the deterioration of the water vapor permeable membrane (41) can be prevented. It is possible to reliably improve the reliability of the humidifying means (45).

[0029]

Embodiment 1 of the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 1, the fuel cell system according to Embodiment 1 includes a fuel cell (10) and a reformer (30). Further, this fuel cell system is provided with a water circulation path (65) and constitutes a so-called cogeneration system.

The fuel cell (10) is of a solid polymer electrolyte type. In this fuel cell (10), a unit cell is constructed by forming electrodes by dispersing catalyst particles on both sides of an electrolyte membrane made of a fluorine-based polymer film. One of the electrodes on the surface of the electrolyte membrane serves as a hydrogen electrode (anode) and the other serves as an oxygen electrode (cathode). The fuel cell (10) constitutes a stack (assembled cell) in which unit cells are stacked via bipolar plates. The structure of the fuel cell (10) described above is omitted in FIG.

In the fuel cell (10), the oxygen electrode side gas passage (11) is formed by the bipolar plate and the oxygen electrode of the electrolyte membrane, and the hydrogen electrode side gas passage (12) is formed by the bipolar plate and the hydrogen electrode of the electrolyte membrane. ) Has been formed. An air supply pipe (20) is connected to the inlet side of the oxygen electrode side gas passageway (11) and an oxygen electrode exhaust pipe (24) is connected to the outlet side thereof. On the other hand, in the hydrogen electrode side gas passageway (12), a reforming device (30) is connected to its inlet side by piping, and a hydrogen electrode exhaust pipe (25) is connected to its outlet side.

A cooling water circuit (60) is connected to the fuel cell (10). The cooling water circuit (60) is a closed circuit filled with cooling water, and the cooling water pump (61)
And the first heat exchanger (71) are connected. By circulating the cooling water in the cooling water circuit (60), the fuel cell (10) is maintained at a predetermined operating temperature.

The air supply pipe (20) has a starting end open to the outside and an ending end connected to the oxygen electrode side gas passage (11) of the fuel cell (10). The air supply pipe (20) is provided with a blower (23) and a gas humidifier (40) in this order from the start end to the end.

The air supply pipe (20) is provided with a first branch pipe (21) and a second branch pipe (22). The start end of the first branch pipe (21) is connected between the gas humidifier (40) and the fuel cell (10). On the other hand, the second branch pipe (22)
The start end of the first branch pipe (21) and the fuel cell (1
Connected between 0). The details of the gas humidifier (40) will be described later.

The reformer (30) is configured to produce a hydrogen-based fuel gas from the natural gas supplied as the raw material gas. In this reforming device (30), a desulfurizer (31), a reformer (33), in order along the flow of gas,
A transformer (34) and a CO remover (35) are provided. Further, the first branch pipe (21) of the air supply pipe (20) is connected to the reformer (30) between the desulfurizer (31) and the reformer (33), and is connected to the transformer (34). The second branch pipe (22) of the air supply pipe (20) is connected between the CO removers (35).

The desulfurizer (31) is configured to adsorb and remove the sulfur content from the natural gas supplied as the raw material gas.

The reformer (33) comprises a catalyst which is active for the partial oxidation reaction and a catalyst which is active for the steam reforming reaction. In the reformer (33), methane (CH ₄ ) is generated by partial oxidation reaction and steam reforming reaction.
Hydrogen is generated from natural gas (that is, raw material gas) whose main component is hydrogen. At that time, the reformer (33) uses the reaction heat of the partial oxidation reaction which is an exothermic reaction as the reaction heat of the steam reforming reaction which is an endothermic reaction.

The shift converter (34) is provided with a catalyst that is active in the shift reaction (carbon monoxide shift reaction). In the shift converter (34), the shift reaction reduces carbon monoxide in the gas and simultaneously increases hydrogen.

The CO remover (35) is equipped with a catalyst that is active in the CO selective oxidation reaction. CO remover (35)
Then, CO in the gas is further reduced by the CO selective oxidation reaction. Then, the hydrogen-based gas discharged from the CO remover (35) is supplied as a fuel gas to the hydrogen electrode side gas passage (12) of the fuel cell (10).

The reformer (30) is provided with a combustor (51) which is a combustor. The end of the combustion air pipe (52) is connected to the combustor (51). The combustion air pipe (52) has a start end connected between the first branch pipe (21) and the second branch pipe (22) in the air supply pipe (20), and air flowing through the air supply pipe (20). Is supplied to the combustor (51). The combustor (51) is configured to burn oxygen (O ₂ ) in the air supplied from the combustion air pipe (52) to burn hydrogen (H ₂ ) remaining in the hydrogen electrode exhaust gas. ing.

Further, the combustion gas pipe (2
6) is connected. The combustion gas pipe (26) is for discharging combustion gas generated by the combustion of hydrogen, and its end is open to the outside. Combustion gas pipe (2
In 6), the 2nd heat exchanger (74) and the gas humidifier (40) are provided in order along the flow of combustion gas. Furthermore,
The end of the oxygen electrode exhaust pipe (24) is connected between the second heat exchanger (74) and the gas humidifier (40) in the combustion gas pipe (26).

The gas humidifier (40) has a water vapor permeable membrane (41). The water vapor permeable film (41) is a water vapor permeable film, and is composed of a hydrophilic film such as a polyvinyl alcohol film or an alginate film. A polymer film having a sulfonic acid group, for example, a perfluorosulfonic acid polymer film may be used as the water vapor permeable film (41).

The gas humidifier (40) is divided into a humidified passage (42) and a combustion gas passage (43).
The humidified side passage (42) and the combustion gas passage (43) are partitioned by the water vapor permeable membrane (41). An air supply pipe (20) is connected to the humidified passage (42), and the air taken into the air supply pipe (20) is introduced therein. A combustion gas pipe (26) is connected to the combustion gas passage (43), and the combustion gas from the combustor (51) is supplied to the oxygen electrode exhaust pipe (2).
Introduced after mixing with the oxygen electrode exhaust gas from 4).

In the first embodiment, in the gas humidifier (40), the air in the humidified side passage (42) is humidified by the steam in the combustion gas, and the air humidified in the gas humidifier (40) is subjected to the first branch. It is supplied to the raw material gas of the reformer (30) through the pipe (21). Therefore, in the first embodiment, the gas humidifier (4
0) and the first branch pipe (21) of the air supply pipe (20) form a gas humidifying means (45).

The water circulation path (65) is a closed circuit filled with heat transfer water. In the first embodiment, this water circulation path (6
5) constitutes the heat recovery means (70). Water circuit (6
5) has a circulation pump (6
6), the first heat exchanger (71), and the second heat exchanger (74)
And a hot water storage tank (67) are provided in order. The heat transfer water circulating in the water circulation path (65) is heated by the first heat exchanger (71) and the second heat exchanger (74) and becomes hot water and is stored in the hot water storage tank (67). The hot water in the hot water storage tank (67) is used for hot water supply as needed.

A cooling water passage (72) and a water passage (73) are defined in the first heat exchanger (71). In the first heat exchanger (71), the cooling water channel (72) is connected to the cooling water circuit (60), and the water channel (73) is the water circulation channel (65).
It is connected to the. The first heat exchanger (71) is configured to exchange heat between the cooling water in the cooling water channel (72) and the heat transfer water in the water channel (73).

A combustion gas passage (75) and a water passage (76) are defined in the second heat exchanger (74). Second
In the heat exchanger (74), the combustion gas passage (75) is connected to the combustion gas pipe (26), and the water passage (76) is the water circulation passage (6).
5) connected to. The second heat exchanger (74) is configured to exchange heat between the combustion gas in the combustion gas passage (75) and the heat transfer water in the water passage (76).

The fuel cell system is further provided with a first temperature sensor (81) and a controller (90). The first temperature sensor (81) is attached to the combustion gas pipe (26) between the second heat exchanger (74) and the end of the oxygen electrode exhaust pipe (24). This 1st temperature sensor (81)
Is for measuring the temperature of the combustion gas that has flowed out of the second heat exchanger (74) and has not been mixed with the oxygen electrode exhaust gas.

The controller (90) includes a first temperature adjusting section (91). The temperature detected by the first temperature sensor (81) is input to the first temperature controller (91). First
The temperature controller (91) receives the input first temperature sensor (81).
Based on the detected temperature, the rotation speed of the circulation pump (66) is changed to increase or decrease the circulation amount of the heat transfer water in the water circulation path (65). The first temperature adjusting section (91) adjusts the heat absorption amount of the heat transfer water in the second heat exchanger (74) so that the temperature detected by the first temperature sensor (81) becomes a predetermined value. Constitutes a means.

-Driving operation- The operation of the fuel cell system will be described.

When the blower (23) is operated, air is taken into the air supply pipe (20). This air is introduced into the humidified side passageway (42) of the gas humidifier (40). On the other hand, the combustor (51) is provided in the combustion gas passage (43) of the gas humidifier (40).
Combustion gas from is introduced. Then, the water vapor in the combustion gas that has permeated the water vapor permeable membrane (41) is supplied to the air in the humidified side passageway (42).

Part of the air humidified by the gas humidifier (40) is sent to the reformer (30) through the first branch pipe (21), and the rest flows through the air supply pipe (20). After that, a part of the air in the air supply pipe (20) is burned into the combustion air pipe (52).
Is sent to the combustor (51) through the air supply pipe (2
0) flow. Then, a part of the air in the air supply pipe (20) is sent to the reformer (30) through the second branch pipe (22), and the rest is used as an oxidant gas on the oxygen electrode side of the fuel cell (10). It is introduced into the gas passage (11). As described above, the gas humidifier (4) is connected to the oxygen electrode side gas passage (11) of the fuel cell (10).
The air humidified in 0) is sent in as oxidant gas,
The electrolyte membrane of the fuel cell (10) is kept in a wet state.

Natural gas containing methane as a main component is supplied to the reformer (30) as a raw material gas. This raw material gas is first introduced into the desulfurizer (31). In the desulfurizer (31), the sulfur content contained in the raw material gas is removed. Air from the first branch pipe (21) is mixed with the raw material gas discharged from the desulfurizer (31). The air sent from the first branch pipe (21) has been humidified by the gas humidifier (40),
Contains water vapor. That is, by mixing the raw material gas with the air from the first branch pipe (21), oxygen (O ₂ ) required for the partial oxidation reaction in the reformer (33) and the reformer (33) are mixed.
The amount of H ₂ O required for the steam reforming reaction in step 1 and the shift reaction in the shift converter (34) is added to the raw material gas.

The raw material gas mixed with air from the first branch pipe (21) is introduced into the reformer (33). That is, the reformer (33) is supplied with the raw material gas which is a mixture of natural gas, air and steam. In the reformer (33),
A partial oxidation reaction of methane (CH ₄ ) and a steam reforming reaction are performed to generate hydrogen (H ₂ ) and carbon monoxide (CO). The reaction formulas of the partial oxidation reaction and the steam reforming reaction in the reformer (33) are as shown below. CH ₄ + 1 / 2O ₂ → CO + 2H ₂ … Partial oxidation reaction CH ₄ + H ₂ O → CO + 3H ₂ … Steam reforming reaction

The reacted gas flowing out from the reformer (33) is sent to the shift converter (34). The gas introduced into the shift converter (34) contains hydrogen and carbon monoxide produced in the reformer (33). In addition, the first branch pipe (2
The steam that was supplied through 1) but was not used in the steam reforming reaction remains. In the transformer (34),
A shift reaction takes place, with a decrease in carbon monoxide and an increase in hydrogen. The reaction formula of the shift reaction is as follows. CO + H ₂ O → CO ₂ + H ₂ … Shift reaction

The gas from the shift converter (34) is mixed with the air from the second branch pipe (22) and then introduced into the CO remover (35). Here, the CO remover (3
The gas sent to 5) contains hydrogen as a main component, but still contains carbon monoxide. This carbon monoxide becomes a catalyst poison of the hydrogen electrode. Therefore, CO remover (35)
Further reduces carbon monoxide in the gas by CO selective oxidation reaction. The reaction formula of the CO selective oxidation reaction is as follows. CO + 1 / 2O ₂ → CO ₂ CO selective oxidation reaction, and the gas whose carbon monoxide has been reduced by the CO remover (35) is supplied to the hydrogen electrode side gas passage (12) of the fuel cell (10) as fuel gas. To be done.

At this time, the CO remover (3
Air humidified by the gas humidifier (40) is supplied to the gas flowing toward 5) through the second branch pipe (22).
The water vapor contained in the air passes through the CO remover (35) and is supplied to the hydrogen electrode side gas passage (12) of the fuel cell (10) as one component of the fuel gas. As a result, the electrolyte membrane of the fuel cell (10) is kept in a wet state.

As described above, in the fuel cell (10), the fuel gas is supplied to the hydrogen electrode side gas passage (12) and the oxidant gas (air) is supplied to the oxygen electrode side gas passage (11). . The fuel cell (10) uses hydrogen in a fuel gas as a fuel and oxygen in an oxidant gas (air) as an oxidant to generate electricity. Specifically, in the fuel cell (10), the following cell reactions are performed on the electrode surfaces of the hydrogen electrode and the oxygen electrode. Hydrogen electrode: 2H ₂ → 4H ⁺ + 4e ⁻ Oxygen electrode: O ₂ + 4H ⁺ + 4e ⁻ → 2H ₂ O This cell reaction converts the chemical energy of the combustion reaction of hydrogen contained in the fuel gas into electric energy.

Gas passage (11) on the oxygen electrode side of the fuel cell (10)
Oxygen electrode exhaust gas is discharged as battery exhaust gas from.
This oxygen electrode exhaust gas contains H ₂ O generated by the cell reaction.
Exists in the state of water vapor. This oxygen electrode exhaust gas is
It flows through the oxygen electrode exhaust pipe (24) and is mixed with the combustion gas in the combustion gas pipe (26).

On the other hand, the hydrogen electrode exhaust gas is discharged as the cell exhaust gas from the hydrogen electrode side gas passage (12) of the fuel cell (10). In this hydrogen electrode exhaust gas, hydrogen that has not been used in the cell reaction remains. Further, H ₂ O generated by the cell reaction exists in the hydrogen gas exhaust gas in the form of water vapor. The hydrogen electrode exhaust gas is sent to the combustor (51) through the hydrogen electrode exhaust pipe (25).

The combustor (51) burns hydrogen in the hydrogen electrode exhaust gas by using oxygen contained in the air from the combustion air pipe (52). Combustion of this hydrogen electrode exhaust gas produces high-temperature combustion gas. In this combustion gas, H ₂ O produced by the combustion of hydrogen exists in the form of water vapor. The combustion gas generated in the combustor (51) flows through the combustion gas pipe (26) and the combustion gas flow path (7) of the second heat exchanger (74).
Introduced to 5). In the second heat exchanger (74), the combustion gas in the combustion gas passage (75) radiates heat to the heat transfer water in the water passage (76).

The combustion gas radiates heat to the heat transfer water in the water channel (76) and then flows out from the combustion gas channel (75). The temperature of the combustion gas flowing out from the combustion gas passage (75) is detected by the first temperature sensor (81). This combustion gas is
After being mixed with the oxygen electrode exhaust gas from the oxygen electrode exhaust pipe (24), it is introduced into the combustion gas passage (43) of the gas humidifier (40).

The combustion gas flowing into the combustion gas passage (43) contains water vapor produced by the cell reaction in the fuel cell (10) and water vapor produced by the combustion of hydrogen in the combustor (51). ing. Then, the water vapor in the combustion gas passes through the water vapor permeable membrane (41) and is supplied to the air in the humidified side passageway (42). The combustion gas deprived of water vapor in the gas humidifier (40) is then discharged outdoors.

When the cooling water pump (61) is operated, the cooling water circulates in the cooling water circuit (60). The cooling water discharged from the cooling water pump (61) is sent to the fuel cell (10) and absorbs heat. Due to the heat absorption of this cooling water, the fuel cell (1
0) is maintained at a predetermined operating temperature (for example, about 85 ° C.). The cooling water that has absorbed heat in the fuel cell (10) is introduced into the cooling water flow path (72) of the first heat exchanger (71). The cooling water radiates heat to the heat transfer water in the water flow path (73) while flowing through the cooling water flow path (72). The cooling water that radiates heat in the first heat exchanger (71) is sucked into the cooling water pump (61). Then, the cooling water pump (61) again sends the cooling water after heat radiation toward the fuel cell (10), and this circulation is repeated.

When the circulation pump (66) is operated, the heat transfer water circulates in the water circulation passage (65). The heat transfer water flowing out from the bottom of the hot water storage tank (67) is sent to the water flow path (73) of the first heat exchanger (71) by the circulation pump (66). In the first heat exchanger (71), the heat transfer water absorbs heat from the cooling water in the cooling water passage (72) while flowing through the water passage (73). That is, the exhaust heat of the fuel cell (10) is recovered by the heat transfer water.

After that, the heat transfer water is introduced into the water flow path (76) of the second heat exchanger (74). In the second heat exchanger (74), the heat transfer water absorbs heat from the combustion gas in the combustion gas passage (75) while flowing through the water passage (76). That is, the heat of combustion of hydrogen remaining in the hydrogen electrode exhaust gas is recovered in the heat transfer water. Then, the heat transfer water discharged from the second heat exchanger (74) is sent back to the hot water storage tank (67) and stored as hot water. The heat transfer water stored as hot water in the hot water storage tank (67) is used for hot water supply.

The first temperature controller (9) of the controller (90)
In 1), the circulation amount of the heat transfer water in the water circulation passage (65) is increased or decreased so that the temperature detected by the first temperature sensor (81) becomes a predetermined value (for example, 90 ° C.). Specifically, when the detected temperature of the first temperature sensor (81) is higher than a predetermined value, the first temperature adjusting section (91) increases the circulation amount of the heat transfer water in the water circulation path (65) to increase the second heat. The heat absorption amount of the heat transfer water in the exchanger (74) is increased. On the contrary, when the detected temperature of the first temperature sensor (81) is lower than the predetermined value, the first temperature control section (91) reduces the circulation amount of the heat transfer water in the water circulation path (65) and the second heat exchange. The heat absorption amount of the heat transfer water in the container (74) is reduced.

-Effects of First Embodiment- According to the first embodiment, since the fuel cell system is provided with the water circulation passage (65) as the heat recovery means (70), the combustion gas and the reformer (30) are provided. Exhaust heat can be recovered from
Furthermore, the recovered exhaust heat can be used to generate hot water for hot water supply.

Further, in the first embodiment, the combustion gas whose temperature is lowered by radiating heat to the heat transfer water in the second heat exchanger (74) is
Supplying to the gas humidifier (40). Here, in the gas humidifier (40), the combustion gas comes into contact with the water vapor permeable membrane (41) in order to separate the water vapor from the combustion gas. The water vapor permeable membrane (41) generally does not have such high heat resistance, and deteriorates when the high temperature combustion gas is brought into direct contact therewith. On the other hand, in the first embodiment, the combustion gas whose temperature is lowered by radiating heat to the heat transfer water is sent to the gas humidifier (40). Therefore, according to the first embodiment, by lowering the temperature of the combustion gas supplied to the gas humidifier (40), it is possible to prevent the water vapor permeable membrane (41) from deteriorating due to being exposed to high temperature. The reliability of the humidifier (40) can be improved.

Further, in the first embodiment, the first temperature control section (91) of the controller (90) increases or decreases the circulation amount of the heat transfer water in the water circulation path (65), so that the gas humidifier (4
The temperature of the combustion gas supplied to 0) is maintained at a predetermined value. Therefore, according to the first embodiment, the gas humidifier (40)
With respect to the combustion gas supplied to the gas humidifier (40), the temperature of the combustion gas can be maintained at a temperature at which deterioration of the water vapor permeable membrane (41) can be avoided and deterioration of the water vapor permeable membrane (41) is prevented. It is possible to reliably improve reliability.

[0072]

Embodiment 2 In Embodiment 2 of the present invention, the arrangement of the combustion air pipe (52) in Embodiment 1 is changed, and an air heating section (57) is installed in the combustion air pipe (52). )
Is provided. In the second embodiment, the second temperature sensor (82) is provided and the controller (9
The second temperature control section (92) is provided in (0). Here, the differences between the second embodiment and the first embodiment will be described.

As shown in FIG. 2, the combustion air pipe (5
The start end of 2) is connected between the second branch pipe (22) in the air supply pipe (20) and the fuel cell (10). The end of the combustion air pipe (52) is connected to the combustor (51) as in the first embodiment.

The air heating section (57) is provided in the middle of the combustion air pipe (52). This air heating unit (57)
Is a reformer (33), a shift converter (34), and a CO remover (3
An air passage formed in the vicinity of 5), wherein the air flowing inside absorbs the exhaust heat of the reformer (33), the transformer (34) and the CO remover (35). ing. And in this Embodiment 2, this air heating part (57) comprises the heat recovery means (70) with the water circulation path (65).

The second temperature sensor (82) is attached to a pipe connecting the CO remover (35) of the reformer (30) and the fuel cell (10). This second temperature sensor (8
2) is for measuring the temperature of the fuel gas before flowing out of the CO remover (35) and being introduced into the hydrogen electrode side gas passage (12).

The temperature detected by the second temperature sensor (82) is input to the second temperature controller (92) of the controller (90). The second temperature control section (92) changes the rotation speed of the blower (23) based on the input detected temperature of the second temperature sensor (82) to increase or decrease the flow rate of air in the air heating section (57). Is configured. The second temperature adjusting section (92) constitutes an adjusting means for adjusting the amount of heat absorbed by the air in the air heating section (57) so that the temperature detected by the second temperature sensor (82) becomes a predetermined value. ing.

-Operational Behavior-In the second embodiment, part of the air taken into the air supply pipe (20) is passed through the first branch pipe (21) and the second branch pipe (22) to the reformer ( 30), a part of the rest is supplied as an oxidant gas to the oxygen electrode side gas passage (11) of the fuel cell (10), and the rest is introduced to the air heating section (57). While this air flows through the air heating section (57), the CO remover (35), the transformer (34), and the reformer (3).
3) The exhaust heat from 3) is absorbed in order and heated. The air heated by the air heating section (57) is sent to the combustor (51).

In the combustor (51), the hydrogen electrode exhaust gas and the air from the combustion air pipe (52) are mixed, and the hydrogen in the hydrogen electrode exhaust gas burns to generate combustion gas. The air supplied from the combustion air pipe (52) to the combustor (51) absorbs the exhaust heat of the reformer (30) in the air heating section (57). Therefore, the temperature of the combustion gas generated in the combustor (51) rises by the amount of heat absorbed by the air in the air heating section (57). Then, in the second heat exchanger (74), the combustion heat of hydrogen in the hydrogen electrode exhaust gas and the exhaust heat of the reformer (30) are applied to the heat transfer water in the water flow path (76).

The second temperature controller (9) of the controller (90)
In 2), the flow rate of air in the air heating section (57) is increased or decreased so that the temperature detected by the second temperature sensor (82) becomes a predetermined value (for example, 85 ° C.). Specifically, when the detected temperature of the second temperature sensor (82) is higher than a predetermined value, the second temperature adjusting section (92) increases the flow rate of air in the air heating section (57) to increase the air heating section (57). ) Increase the endothermic amount of air. When the amount of absorbed heat of air in the air heating section (57) increases, the temperature of the fuel gas flowing out from the CO remover (35) decreases. On the contrary, when the detected temperature of the second temperature sensor (82) is lower than the predetermined value, the second temperature adjusting section (92) reduces the flow rate of air in the air heating section (57), and the air heating section (57). The endothermic amount of air at. When the amount of heat absorbed by the air in the air heating unit (57) decreases, the temperature of the fuel gas flowing out from the CO remover (35) rises.

[0080]

Third Embodiment A third embodiment of the present invention differs from the second embodiment in that the combustion air pipe (52) is omitted and the oxygen electrode exhaust pipe (24) is modified.
Here, the differences between the third embodiment and the second embodiment will be described.

As shown in FIG. 3, the oxygen electrode exhaust pipe (24) of the third embodiment has its end connected to the combustor (51). A heat recovery unit (27) is provided in the middle of the oxygen electrode exhaust pipe (24). The heat recovery section (27) is a gas passage formed in the vicinity of the reformer (33), the shift converter (34), and the CO remover (35), and the oxygen electrode exhaust gas flowing inside is modified. It is configured to absorb the exhaust heat of the quality device (33), the transformer (34), and the CO remover (35). Then, in the third embodiment, the heat recovery section (27) constitutes the heat recovery means (70) together with the water circulation path (65).

In the second embodiment, the oxygen electrode exhaust gas discharged from the oxygen electrode side gas passage (11) of the fuel cell (10) flows through the oxygen electrode exhaust pipe (24) and is introduced into the heat recovery section (27). To be done. In the oxygen electrode exhaust gas, H ₂ O generated by the cell reaction in the fuel cell (10) and oxygen not used in the cell reaction remain. While flowing through the heat recovery section (27), the oxygen electrode exhaust gas absorbs the exhaust heat from the CO remover (35), the shift converter (34), and the reformer (33) in order and is heated. The oxygen electrode exhaust gas heated in the heat recovery section (27) is then sent to the combustor (51).

The combustor (51) of the third embodiment uses the oxygen remaining in the oxygen electrode exhaust gas to burn hydrogen in the hydrogen electrode exhaust gas. Here, the oxygen electrode exhaust gas supplied to the combustor (51) is reformed (30) in the heat recovery section (27).
It absorbs the exhaust heat of. Therefore, the temperature of the combustion gas generated in the combustor (51) rises by the amount of heat absorbed by the oxygen electrode exhaust gas in the heat recovery section (27). Then, in the second heat exchanger (74), the combustion heat of hydrogen in the hydrogen electrode exhaust gas and the exhaust heat of the reformer (30) are applied to the heat transfer water in the water flow path (76).

The second temperature controller (9) of the controller (90)
2) is a supply of an oxidant gas (air) to the oxygen electrode side gas passage (11) of the fuel cell (10) so that the temperature detected by the second temperature sensor (82) becomes a predetermined value (for example, 85 ° C.). The amount is changed to increase or decrease the flow rate of the oxygen electrode exhaust gas in the heat recovery section (27). Specifically, when the detected temperature of the second temperature sensor (82) is higher than a predetermined value, the second temperature adjusting section (92)
Increase the flow rate of oxygen electrode exhaust gas in the heat recovery section (27),
The heat absorption amount of the oxygen electrode exhaust gas in the heat recovery section (27) is increased. When the heat absorption amount of the oxygen electrode exhaust gas in the heat recovery section (27) increases, the temperature of the fuel gas flowing out from the CO remover (35) decreases. On the contrary, when the detected temperature of the second temperature sensor (82) is lower than the predetermined value, the second temperature adjusting section (92)
Reduce the flow rate of oxygen electrode exhaust gas in the heat recovery section (27),
The endothermic amount of the oxygen electrode exhaust gas in the heat recovery section (27) is reduced. When the heat absorption amount of the oxygen electrode exhaust gas in the heat recovery section (27) decreases, the temperature of the fuel gas flowing out from the CO remover (35) rises.

[0085]

[Fourth Embodiment of the Invention] A fourth embodiment of the present invention is the same as the above-described first embodiment, except that a heat recovery section (77) is provided in the water circulation path (65). Further, in the fourth embodiment, the second temperature sensor (82) is provided and the controller (90) is provided.
The second temperature control section (92) is provided in the. here,
The differences between the fourth embodiment and the first embodiment will be described.

As shown in FIG. 4, the heat recovery section (77)
Is the first heat exchanger (71) and the second in the water circuit (65).
It is provided between the heat exchangers (74). The heat recovery section (77) is a passage for the heat transfer water formed in the vicinity of the reformer (33), the shift converter (34), and the CO remover (35), and the heat transfer water flowing inside the heat transfer water Is configured to absorb the exhaust heat of the reformer (33), the shift converter (34), and the CO remover (35).

The second temperature sensor (82) is attached to a pipe connecting the CO remover (35) of the reformer (30) and the fuel cell (10). This second temperature sensor (8
2) is for measuring the temperature of the fuel gas before flowing out of the CO remover (35) and being introduced into the hydrogen electrode side gas passage (12).

The temperature detected by the second temperature sensor (82) is input to the second temperature controller (92) of the controller (90). The second temperature adjusting section (92), based on the input temperature detected by the second temperature sensor (82), the circulation pump (66).
Is changed to increase or decrease the flow rate of the heat transfer water in the heat recovery section (77). The second temperature adjusting section (92) has an adjusting means for adjusting the heat absorption amount of the heat transfer water in the heat recovery section (77) so that the temperature detected by the second temperature sensor (82) becomes a predetermined value. I am configuring.

-Operational Behavior- The heat transfer water circulating in the water circulation path (65) first exchanges heat with the cooling water circulating in the cooling water circuit (60) in the first heat exchanger (71), and the fuel cell ( It absorbs the exhaust heat of 10). Then, the heat transfer water is introduced into the heat recovery section (77). While flowing through the heat recovery section (77), the exhaust heat from the CO remover (35), the shift converter (34), and the reformer (33) is sequentially absorbed.
Then, the heat transfer water is introduced into the second heat exchanger (74) and absorbs heat from the combustion exhaust gas. And a 1st heat exchanger (71),
The heat transfer water heated in the heat recovery section (77) and the second heat exchanger (74) is stored in the hot water storage tank (67) as hot water.

The second temperature controller (9) of the controller (90)
In 2), the flow rate of the heat transfer water in the heat recovery section (77) is increased or decreased so that the temperature detected by the second temperature sensor (82) becomes a predetermined value (for example, 85 ° C.). Specifically, when the detected temperature of the second temperature sensor (82) is higher than a predetermined value, the second temperature adjustment section (92) increases the flow rate of the heat transfer water in the heat recovery section (77) to increase the heat recovery section. Increase the endothermic amount of heat transfer water in (77). When the heat absorption amount of the heat transfer water in the heat recovery section (77) increases, the temperature of the fuel gas flowing out from the CO remover (35) decreases. On the contrary, when the detected temperature of the second temperature sensor (82) is lower than the predetermined value, the second temperature adjustment section (92) reduces the flow rate of the heat transfer water in the heat recovery section (77), and the heat recovery section ( Decrease the endothermic amount of heat transfer water in 77). When the heat absorption amount of the heat transfer water in the heat recovery section (77) decreases, the temperature of the fuel gas flowing out from the CO remover (35) rises.

[0091]

Other Embodiments of the Invention-First Modification-In the water circulation passageway (65) of each of the above-mentioned embodiments, as shown in FIG. 5, instead of the second heat exchanger (74), a water heating section ( 78) may be provided. Note that FIG. 5 is a diagram in which this modification is applied to the first embodiment. The water heating section (78) is a passage for the heat transfer water formed in the vicinity of the combustor (51) so that the heat transfer water flowing inside absorbs the heat released from the combustor (51). Is configured.

-Second Modification- In each of the above embodiments, the combustion gas pipe (26) may be provided with an auto heat exchanger. This self heat exchanger is a combustor (51)
It is configured to preheat the air or the hydrogen electrode exhaust gas by exchanging heat with the combustion gas or the air or the hydrogen electrode exhaust gas introduced into the. When the air or the hydrogen electrode exhaust gas introduced into the combustor (51) is preheated in this way, the temperature of the combustion gas generated in the combustor (51) rises and the heat medium at the outlet of the second heat exchanger (74) is increased. The water temperature rises. Therefore, according to this modification, the temperature of the heat transfer water stored as hot water in the hot water storage tank (67) can be increased.

-Third Modification- In the second, third and fourth embodiments, the air heating section (57) and the heat recovery section (27, 77) are provided, and the reformer (33), the transformer (34),
Exhaust heat is recovered from all of the CO and CO removers (35), but it is not always necessary to recover exhaust heat from all of them. For example, only the exhaust heat of the CO remover (35) may be recovered by the air heating section (57) or the heat recovery section (27, 77).

-Fourth Modification- In the second, third and fourth embodiments, the air heating section (57) and the heat recovery section (27, 77) are provided, and the reformer (33), the transformer (34),
Alternatively, the exhaust heat is recovered from the CO remover (35), but instead of this, the gas discharged from the reformer (33) and sent to the shift converter (34), and the CO discharged from the shift converter (34). Gas sent to the scavenger (35) or CO gas scavenger (35) exits the fuel cell (1
The exhaust heat may be recovered from the gas sent to 0). Of course, the reformer (33), the shift converter (34), the CO remover (35), the gas discharged from the reformer (33) to the shift converter (34), and the gas discharged from the shift converter (34) to CO. Gas sent to the eliminator (35), and gas from the CO eliminator (35) (1)
The exhaust heat may be recovered from all the gas sent to (0).

-Fifth Modification- In the second, third and fourth embodiments, the second temperature sensor (82) is connected to the pipe connecting the CO remover (35) of the reformer (30) and the fuel cell (10). ) Is attached, and the amount of exhaust heat recovered by the air heating part (57) and the heat recovery parts (27, 77) is adjusted to the second value so that the temperature of the fuel gas supplied to the fuel cell (10) reaches a predetermined value.
Although the temperature is adjusted appropriately by the temperature controller (92), the following configuration may be used instead.

That is, the transformer (34) and the CO remover (35)
Attach the second temperature sensor (82) to the pipe connecting to
The amount of exhaust heat recovered by the air heating part (57) and the heat recovery parts (27, 77) is adjusted to the second temperature control part (92) so that the temperature of the gas supplied to the CO remover (35) becomes a predetermined value. ). Similarly, the second temperature sensor (82) is attached to the pipe connecting the reformer (33) and the transformer (34), and the temperature of the gas supplied to the transformer (34) reaches a predetermined value. Therefore, the amount of exhaust heat recovered by the air heating part (57) and the heat recovery parts (27, 77) may be adjusted by the second temperature adjustment part (92).

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a fuel cell system according to a first embodiment.

FIG. 2 is a schematic configuration diagram of a fuel cell system according to a second embodiment.

FIG. 3 is a schematic configuration diagram of a fuel cell system according to a third embodiment.

FIG. 4 is a schematic configuration diagram of a fuel cell system according to a fourth embodiment.

FIG. 5 is a schematic configuration diagram of a fuel cell system according to another embodiment (first modification).

[Explanation of symbols]

(10) Fuel cell (11) Oxygen electrode side gas passage (12) Hydrogen side gas passage (30) Reformer (33) Reformer (34) Transformer (35) CO remover (41) Water vapor permeable membrane (45) Gas humidification means (51) Combustor (combustion section) (70) Heat recovery means (91) First temperature control section (control means) (92) Second temperature control section (control means)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shuji Ikegami             Daikin, 3-12, Chikkoshinmachi, Sakai City, Osaka Prefecture             Sakai Works Co., Ltd. (72) Inventor Eisaku Okubo             1304 Kanaoka-cho, Sakai City, Osaka Prefecture Daikin Industries             Sakai Plant Kanaoka Factory (72) Inventor Toshiyuki Kurihara             1304 Kanaoka-cho, Sakai City, Osaka Prefecture Daikin Industries             Sakai Plant Kanaoka Factory F-term (reference) 5H026 AA06 CX04                 5H027 AA06 BA01 BA05 BA09 DD06                       KK41

Claims (9)

[Claims] 1. A reforming device (30) for reforming the supplied raw material gas to produce a fuel gas, and an oxidant gas supplied to a gas passage (11) on the oxygen electrode side and the reforming device (30). The fuel gas produced in 30) is supplied to the gas passage (12) on the hydrogen electrode side, and the hydrogen discharged from the gas passage (12) on the hydrogen electrode side of the fuel cell (10). A combustion part (51) for combusting polar exhaust gas to generate combustion gas, a heat recovery means (70) for recovering heat from the combustion gas to generate hot water for hot water supply, and the heat recovery means (70). A fuel cell system comprising: a gas humidifying means (45) for humidifying at least the above-mentioned raw material gas by utilizing the water vapor separated by the water vapor permeable membrane (41) from the combustion gas recovered in heat. 2. A reformer (30) for reforming the supplied raw material gas to produce a fuel gas, and an oxidant gas supplied to a gas passage (11) on the oxygen electrode side and said reformer ( The fuel gas produced in 30) is supplied to the gas passage (12) on the hydrogen electrode side, and the hydrogen discharged from the gas passage (12) on the hydrogen electrode side of the fuel cell (10). A combustor (51) for combusting polar exhaust gas to generate combustion gas, and a gas humidifying means (45) for humidifying at least the raw material gas by using the steam separated from the combustion gas by the steam permeable membrane (41). And a heat recovery means (70) for recovering heat from the reforming device (30) to generate hot water for hot water supply. 3. The fuel cell system according to claim 2, wherein the heat recovery means (70) is configured to also recover heat from the combustion gas sent from the combustion section (51) to the gas humidification means (45). Fuel cell system. 4. The fuel cell system according to claim 1 or 3, wherein the heat recovery means (70) recovers from the combustion gas so that the temperature of the combustion gas sent to the gas humidification means (45) becomes a predetermined value. A fuel cell system comprising an adjusting means (91) for adjusting the amount of heat. 5. The fuel cell system according to claim 2 or 3, wherein the reformer (30) comprises a reformer (33), a shift converter (34), and a CO.
The heat recovery means (70) is configured to produce a fuel gas by circulating the gas in the order of the remover (35), and the heat recovery means (70) or the reformer (33) leaving the reformer (33). The amount of heat recovered by the heat recovery means (70) so as to recover the heat from the gas sent to the transformer (34) so that the temperature of the gas flowing into the converter (34) becomes a predetermined value. A fuel cell system comprising adjusting means (92) for adjusting the fuel cell. 6. The fuel cell system according to claim 2 or 3, wherein the reformer (30) comprises a reformer (33), a shift converter (34) and a CO.
The heat recovery circuit is configured such that the gas is circulated in the order of the remover (35) to produce the fuel gas, and the heat recovery circuit is the above-mentioned transformer (34) or the transformer (34).
Is configured to recover heat from the gas discharged from the CO and sent to the CO remover (35), while the heat recovery means (so that the temperature of the gas flowing into the CO remover (35) reaches a predetermined value ( A fuel cell system comprising a control means (92) for controlling the amount of heat recovered by the (70). 7. The fuel cell system according to claim 2 or 3, wherein the reformer (30) comprises a reformer (33), a shift converter (34), and a CO.
The heat recovery circuit is configured to produce a fuel gas by circulating the gas in the order of the remover (35), and the heat recovery circuit outputs the CO remover (35) or the CO remover (35). ), While adjusting the amount of heat recovered by the heat recovery means (70) so that the temperature of the fuel gas flowing into the fuel cell (10) reaches a predetermined value. A fuel cell system provided with adjusting means (92) for controlling. 8. The fuel cell system according to claim 1 or 2, wherein the heat recovery means (70) is also configured to recover heat from the fuel cell (10). 9. The fuel cell system according to claim 1, wherein the oxygen electrode exhaust gas is discharged from the gas passage (11) on the oxygen electrode side of the fuel cell (10), while the heat recovery means (70) comprises: A fuel cell system configured to heat air or the oxygen electrode exhaust gas by exhaust heat of a reforming device (30) and supply the heated exhaust gas to a combustion section (51).