WO2012091096A1

WO2012091096A1 - Fuel cell system

Info

Publication number: WO2012091096A1
Application number: PCT/JP2011/080401
Authority: WO
Inventors: 暁山本
Original assignee: Ｊｘ日鉱日石エネルギー株式会社
Priority date: 2010-12-28
Filing date: 2011-12-28
Publication date: 2012-07-05
Also published as: JPWO2012091096A1

Abstract

A fuel cell system is provided with: a system body that has a power generation unit containing a fuel cell stack for generating power using hydrogen-containing gas, and a chassis for housing the power generation unit; a heat supply unit for supplying an amount of heat according to heat demand, and including a combustion unit; and an air channel for circulating outside air within the chassis, and cooling the interior of the chassis. A first branch channel for supplying air to the fuel cell stack in the power generation unit, and a second branch channel for supplying air to the combustion unit in the heat supply unit are included in the downstream side of the air channel. A first ventilation unit for pumping air toward the fuel cell stack in the power generation unit, and a second ventilation unit for pumping air toward the combustion unit in the heat supply unit are provided in the air channel.

Description

Fuel cell system

The present invention relates to a fuel cell system.

Conventionally, for example, a fuel cell system described in Patent Document 1 is known. In such a fuel cell system, a power generation unit including a cell stack that generates power using a hydrogen-containing gas is housed in a casing, and an external fan is operated by operating a fan (blower unit) installed in the casing. The air is taken into the housing to cool the inside of the housing, and the outside air is supplied to the cell stack of the power generation unit.

JP 2007-207441 A

Here, in recent fuel cell systems, for example, with the miniaturization and high density of the system, it is particularly required that the inside of the housing can be sufficiently cooled. In this regard, in the fuel cell system as described above, for example, the amount of air circulating in the housing is limited to the amount of cathode air supplied to the power generation unit, and thus there is a risk that cooling in the housing will be insufficient.

Therefore, an object of the present invention is to provide a fuel cell system that can sufficiently cool the inside of the casing.

In order to solve the above-described problem, a fuel cell system according to one aspect of the present invention includes a power generation unit including a cell stack that generates power using a hydrogen-containing gas, and a system main body including a housing that houses the power generation unit. And a heat supply section that includes a combustion section inside and supplies heat according to heat demand, and an air flow path that cools the inside of the casing by circulating external air inside the casing. And a downstream side of the air flow path includes a first branch flow path that supplies air to the cell stack of the power generation unit, and a second branch flow path that supplies air to the combustion unit of the heat supply unit. The path is provided with a first blower that pumps air toward the cell stack of the power generation unit and a second blower that pumps air toward the combustion unit of the heat supply unit.

In the fuel cell system of the present invention, the inside of the casing can be selectively and sequentially (efficiently) cooled by the air flow path, instead of being uniformly ventilated and cooled. In addition, the inside of the housing can be cooled not only by the air supplied to the cell stack of the power generation unit but also by the air supplied to the combustion unit of the heat supply unit. Therefore, according to the present invention, the inside of the housing can be sufficiently cooled.

1 is a schematic block diagram showing a fuel cell system according to a first embodiment. It is a schematic block diagram which shows the principal part of the fuel cell system which concerns on 1st Embodiment. It is a schematic block diagram which shows the principal part in the modification of the fuel cell system shown in FIG. It is a schematic block diagram which shows the principal part in the other modification of the fuel cell system shown in FIG. It is a schematic block diagram which shows the principal part of the fuel cell system which concerns on 2nd Embodiment. 6 is a flowchart showing an example of an operation when the control based on the temperature in the housing is not performed in the fuel cell system of FIG. 5. 6 is a flowchart showing an example of an operation in the case of performing control based on the temperature in the casing in the fuel cell system of FIG. 5. It is a schematic block diagram which shows the principal part in the modification of the fuel cell system shown in FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

FIG. 1 is a schematic block diagram showing a fuel cell system according to the first embodiment. As shown in FIG. 1, the fuel cell system 1 includes a desulfurization unit 2, a water vaporization unit 3, a hydrogen generation unit 4, a cell stack 5, an offgas combustion unit 6, a hydrogen-containing fuel supply unit 7, A supply unit 8, an oxidant supply unit 9, a power conditioner 10, and a control unit 11 are provided.

The fuel cell system 1 generates power in the cell stack 5 using a hydrogen-containing fuel and an oxidant. The type of the cell stack 5 in the fuel cell system 1 is not particularly limited, and examples thereof include a polymer electrolyte fuel cell (PEFC), a solid oxide fuel cell (SOFC), and phosphoric acid. A fuel cell (PAFC: Phosphoric Acid Fuel Cell), a molten carbonate fuel cell (MCFC: Molten Carbonate Fuel Cell), and other types can be employed. 1 may be appropriately omitted depending on the type of cell stack 5, the type of hydrogen-containing fuel, the reforming method, and the like.

As the hydrogen-containing fuel, for example, a hydrocarbon fuel is used. As the hydrocarbon fuel, a compound containing carbon and hydrogen in the molecule (may contain other elements such as oxygen) or a mixture thereof is used. Examples of hydrocarbon fuels include hydrocarbons, alcohols, ethers, and biofuels. These hydrocarbon fuels are derived from conventional fossil fuels such as petroleum and coal, and synthetic systems such as synthesis gas. Those derived from fuel and those derived from biomass can be used as appropriate. Specific examples of hydrocarbons include methane, ethane, propane, butane, natural gas, LPG (liquefied petroleum gas), city gas, town gas, gasoline, naphtha, kerosene, and light oil. Examples of alcohols include methanol and ethanol. Examples of ethers include dimethyl ether. Examples of biofuels include biogas, bioethanol, biodiesel, and biojet.

As the oxidizing agent, for example, air, pure oxygen gas (which may contain impurities that are difficult to remove by a normal removal method), or oxygen-enriched air is used.

The desulfurization unit 2 desulfurizes the hydrogen-containing fuel supplied to the hydrogen generation unit 4. The desulfurization part 2 has a desulfurization catalyst for removing sulfur compounds contained in the hydrogen-containing fuel. As the desulfurization method of the desulfurization unit 2, for example, an adsorptive desulfurization method that adsorbs and removes sulfur compounds and a hydrodesulfurization method that removes sulfur compounds by reacting with hydrogen are employed. The desulfurization unit 2 supplies the desulfurized hydrogen-containing fuel to the hydrogen generation unit 4.

The water vaporization unit (water vaporizer) 3 generates water vapor supplied to the hydrogen generation unit 4 by heating and vaporizing water. For the heating of the water in the water vaporization unit 3, for example, heat generated in the fuel cell system 1 such as recovering the heat of the hydrogen generation unit 4, the heat of the off-gas combustion unit 6, or the heat of the exhaust gas may be used. Moreover, you may heat water using other heat sources, such as a heater and a burner separately. In FIG. 1, only heat supplied from the off-gas combustion unit 6 to the hydrogen generation unit 4 is described as an example, but the present invention is not limited to this. The water vaporization unit 3 supplies the generated water vapor to the hydrogen generation unit 4.

The hydrogen generation unit 4 generates a hydrogen rich gas (hydrogen-containing gas) using the hydrogen-containing fuel from the desulfurization unit 2. The hydrogen generator 4 has a reformer that reforms the hydrogen-containing fuel with a reforming catalyst. The reforming method in the hydrogen generating unit 4 is not particularly limited, and for example, steam reforming, partial oxidation reforming, autothermal reforming, and other reforming methods can be employed. The hydrogen generator 4 may have a configuration for adjusting the properties in addition to the reformer reformed by the reforming catalyst depending on the properties of the hydrogen rich gas required for the cell stack 5. For example, when the type of the cell stack 5 is a polymer electrolyte fuel cell (PEFC) or a phosphoric acid fuel cell (PAFC), the hydrogen generation unit 4 is configured to remove carbon monoxide in the hydrogen-rich gas. (For example, a shift reaction part and a selective oxidation reaction part). The hydrogen generation unit 4 supplies a hydrogen rich gas to the anode 12 of the cell stack 5.

The cell stack 5 generates power using the hydrogen rich gas from the hydrogen generation unit 4 and the oxidant from the oxidant supply unit 9. The cell stack 5 includes an anode 12 to which a hydrogen-rich gas is supplied, a cathode 13 to which an oxidant is supplied, and an electrolyte 14 disposed between the anode 12 and the cathode 13. The cell stack 5 supplies power to the outside via the power conditioner 10. The cell stack 5 supplies the hydrogen rich gas and the oxidant, which have not been used for power generation, to the off gas combustion unit 6 as off gas. Note that a combustion section (for example, a combustor that heats the reformer) provided in the hydrogen generation section 4 may be shared with the off-gas combustion section 6.

The off gas combustion unit 6 burns off gas supplied from the cell stack 5. The heat generated by the off-gas combustion unit 6 is supplied to the hydrogen generation unit 4 and used for generation of a hydrogen rich gas in the hydrogen generation unit 4.

The hydrogen-containing fuel supply unit 7 supplies hydrogen-containing fuel to the desulfurization unit 2. The water supply unit 8 supplies water to the water vaporization unit 3. The oxidant supply unit 9 supplies an oxidant to the cathode 13 of the cell stack 5. The hydrogen-containing fuel supply unit 7, the water supply unit 8, and the oxidant supply unit 9 are configured by a pump, for example, and are driven based on a control signal from the control unit 11. When the hydrogen-containing fuel supply unit 7 supplies a hydrogen-containing fuel that does not require a reforming process, such as pure hydrogen gas or hydrogen-enriched gas, the desulfurization unit 2, the water supply unit 8, the water vaporization unit 3 and one or more of the hydrogen generators 4 can be omitted.

The power conditioner 10 adjusts the power from the cell stack 5 according to the external power usage state. For example, the power conditioner 10 performs a process of converting a voltage and a process of converting DC power into AC power.

The control unit 11 performs control processing for the entire fuel cell system 1. The control unit 11 is configured by a device including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and an input / output interface, for example. The control unit 11 is electrically connected to a hydrogen-containing fuel supply unit 7, a water supply unit 8, an oxidant supply unit 9, a power conditioner 10, and other sensors and auxiliary equipment not shown. The control unit 11 acquires various signals generated in the fuel cell system 1 and outputs a control signal to each device in the fuel cell system 1.

FIG. 2 is a schematic block diagram showing a main part of the fuel cell system according to the first embodiment. As shown in FIG. 2, the fuel cell system 1 includes a system main body 20 and a backup boiler (heat supply unit) 30.

The system main body 20 includes a power generation unit 21, the power conditioner 10, and first and second

auxiliary machine modules

22 and 23, and these are airtightly accommodated so as to be installed in the housing 24. . In the system body 20 here, the first auxiliary machine module 22, the power generation unit 21, the second auxiliary machine module 23, and the power conditioner 10 are arranged in this order from the upper side to the lower side, and have a tandem arrangement structure.

The power generation unit 21 is a module that generates power, and includes the desulfurization unit 2, the water vaporization unit 3, the hydrogen generation unit 4, the cell stack 5, the offgas combustion unit 6, the hydrogen-containing fuel supply unit 7, and the water At least a supply unit 8 and the oxidant supply unit 9 are provided. The power generation unit 21 is accommodated in a box (chamber) 21a and modularized.

The power conditioner 10 adjusts the electric power generated by the cell stack 5 of the power generation unit 21 as described above. The power conditioner 10 has a control panel as the control unit 11 that controls the operation of the power generation unit 21. The power conditioner 10 is housed in a box (chamber) 10a and modularized, like the power generation unit 21.

The first and second

auxiliary machine modules

22 and 23 are peripheral devices for generating power in the power generation unit. As with the power generation unit 21 and the power conditioner 10, each of the

auxiliary machine modules

22 and 23 is housed and modularized in box bodies (chambers) 22 a and 23 a.

Each

box

10a, 21a, 22a, 23a includes an air inlet (not shown) and an air outlet (not shown). And the air inflow part and air outflow part of

adjacent box

10a, 21a, 22a, 23a are connected so that the inflow / outflow of air is possible, and the air flow path is formed.

The backup boiler 30 supplies a deficient amount of heat with respect to heat demand to water in a heat recovery system (not shown) (so-called additional hot water supply is performed). The backup boiler 30 has a combustion part 30a such as a burner. The backup boiler 30 is provided so as to be coupled to the system main body 20. That is, the system main body 20 and the backup boiler 30 are integrated with each other.

Further, the fuel cell system 1 includes an air flow path 25, a cathode blower (first air blowing unit) 26, and a combustion unit blower (second air blowing unit) 27. The air flow path 25 circulates external air inside the housing 24 and cools the inside of the housing 24. The cathode blower 26 is provided in the air flow path 25, and feeds air to the cathode 13 (see FIG. 1) of the cell stack 5 in the power generation unit 21 to send air. The combustion section blower 27 is provided in the air flow path 25, and feeds air to the combustion section 30 a in the backup boiler 30 by pressure.

The air flow path 25 circulates air so that the power conditioner 10, the second auxiliary module 23, the power generation unit 21, and the first auxiliary module 22 are cooled in this order in the housing 24. Specifically, as shown below, air is sequentially circulated in the plurality of

boxes

10a, 23a, 21a, and 22a so as to cool the plurality of modules (equipment) in order from the lowest guaranteed operating temperature. .

That is, in the air flow path 25, external air (outdoor air) is first taken into the housing 24 through the flue pipe (air pipe) T by the operation of the cathode blower 26 and the combustion section blower 27. . And the said air flows in into the box 10a which accommodates the power conditioner 10, and the power conditioner 10 is cooled. Subsequently, the air after cooling the power conditioner 10 flows into the box body 23a that houses the second auxiliary machine module 23, and the second auxiliary machine module 23 is cooled. Subsequently, the air after cooling the second auxiliary equipment module 23 flows into the box 21 a that houses the power generation unit 21, and the power generation unit 21 is cooled. Subsequently, the air after cooling the power generation unit 21 flows into the box 22 a that houses the first auxiliary machine module 22, and the second auxiliary machine module 22 is cooled.

Here, the air channel 25 of the present embodiment has a first branch channel 51 that supplies air to the cell stack of the power generation unit 21 and a first gas channel that supplies air to the combustion unit 30a of the backup boiler 30 on the downstream side. A two-branch channel 52. The air flow path 25 here is bifurcated into first and second

branch flow paths

51 and 52 inside the first auxiliary machine module 22. The first branch passage 51 is provided with the cathode blower 26, and the second branch passage 52 is provided with the combustion section blower 27.

As a result, the air after cooling the first auxiliary machine module 22 is supplied to the cathode 13 of the cell stack 5 (see FIG. 1) via the cathode blower 26, and at the same time, the combustion section 30a of the backup boiler 30 is combusted. It will be supplied through the blower 27 for use.

As mentioned above, in this embodiment, the inside of the housing | casing 24 can be cooled not only with the air supplied to the cell stack 5 of the electric power generation part 21, but with the air supplied to the combustion part 30a of the backup boiler 30. FIG. Therefore, according to this embodiment, the inside of the housing 24 can be sufficiently cooled. In addition, instead of uniformly ventilating and cooling the inside of the casing 24, the inside of the casing 24 can be selectively and sequentially (efficiently) cooled by the air flow path 25.

In the present embodiment, as described above, the air flow path 25 allows the plurality of modules (the power conditioner 10, the first and second

auxiliary equipment modules

22 and 23, and the power generation unit 21) in the housing 24 to operate at a guaranteed temperature. Air is circulated so as to cool in ascending order. Therefore, a plurality of modules can be efficiently cooled in the casing 24, the necessity of the cathode blower 26 and the combustion portion blower 27 having an excessive air blowing capacity can be reduced, and the economic efficiency of the system can be improved. It becomes.

In addition, since the cathode blower 26 and the combustion portion blower 27 having an excessive blowing capacity are not required in this way, it is possible to suppress excessive power consumption and noise of the cathode blower 26 and the combustion portion blower 27. . Further, in the present embodiment, as described above, external air is supplied to the cell stack 5 and the combustion unit 30a on the downstream side of the air flow path 25, so that it is possible to suppress heat from being accumulated in the casing 24. it can. Further, the air whose temperature has been increased by cooling the inside of the housing 24 can be supplied to the cell stack 5.

Further, in the present embodiment, it is possible to suppress occurrence of pressure loss more than necessary in the air flow path 25. Furthermore, each module can be cooled according to the temperature required by each module.

FIG. 3 is a schematic block diagram showing a main part in a modification of the fuel cell system shown in FIG. As shown in FIG. 3, in the fuel cell system 1, the branch point P of the first and

second branch channels

51, 52 is located outside the first auxiliary module 22 in the air channel 25, and the branch point P A manifold portion 53 may be provided. The manifold portion 53 is a space portion having a flow area larger than that of the air flow path 25, and functions as a buffer tank that temporarily stores air.

In the fuel cell system 1 of this modification, the manifold portion 53 can suppress pulsation of air supplied to the cell stack 5 and air supplied to the combustion portion 30a.

FIG. 4 is a schematic block diagram showing a main part in another modification of the fuel cell system shown in FIG. As shown in FIG. 4, the fuel cell system 1 may include a combined blower 28 instead of the combustion portion blower 27.

The combined blower 28 also serves as the first and second air blowing sections, and is provided upstream of the branch point P of the first and second

branch flow paths

51 and 52 in the air flow path 25. Here, the dual-purpose blower 28 is installed in an intake port which is a connection portion with the flue pipe T in the housing 24. The combined blower 28 pumps and blows air having an air amount corresponding to the sum of the air amount supplied to the cell stack 5 and the air amount supplied to the combustion unit 30a.

In the fuel cell system according to another modified example, a part of the air pressure-fed by the dual-purpose blower 28 is supplied to the cell stack 5 by the cathode blower 26, and the remaining part is supplied to the combustion unit 30a as combustion air. It becomes. This makes it possible to supply more accurate air to the cell stack 5.

Next, a second embodiment will be described. In the description of the present embodiment, differences from the first embodiment will be mainly described.

FIG. 5 is a schematic block diagram showing the main part of the fuel cell system according to the second embodiment. As shown in FIG. 5, the fuel cell system 50 of this embodiment includes a hot water tank 19, a heat medium circulation channel 55, a first heat exchange unit 16 a, a second heat exchange unit (heat exchange unit) 30 b, and a temperature measurement unit. 18 and a control unit 15 are further provided.

The hot water storage tank 19 stores water such as clean water supplied from outside, collects heat from the heat medium flowing through the heat medium circulation passage 55 passing through the inside, and stores the heat in the stored water. Moreover, this hot water storage tank 19 discharge | releases the water stored via the hot water supply line 19a as warm water according to a user's etc. demand, for example. The hot water supply line 19a is provided so as to pass through the combustion unit 30a. Thus, when the temperature of the upper part of the hot water storage tank 19 is low, for example, the heat quantity of the hot water is increased by heating the combustion unit 30a so that the hot water becomes a desired temperature. Be compensated.

The heat medium circulation channel 55 circulates the heat medium between the hot water tank 19 and the fuel cell system 50. The heat medium circulation channel 55 here circulates the heat medium among the hot water tank 19, the first heat exchange unit 16a, and the second heat exchange unit 30b. As the heat medium, for example, antifreeze or high boiling point oil is used. In this case, the hot water storage tank 19 of FIG. 5 may be provided with a flow path / heat exchange section as indicated by a broken line, and the heat medium circulation path 55 may be a closed system. According to this, the heat recovered by the heat medium circulation path 55 moves to the water in the hot water storage tank 19, and the heat medium flows again toward the first heat exchange unit 16a. In addition, when using water as a heat medium, the water of the hot water tank 19 can also be used as a heat medium. In this case, the broken line part in the hot water storage tank 19 of FIG. 5 can be made unnecessary.

The first heat exchanging unit 16a recovers heat in the exhaust gas from the cell stack 5 to the heat medium, on the first exhaust gas passage 61 through which the exhaust gas from the cell stack 5 circulates, and in the heat medium circulation flow It is provided on the path 55. In the present embodiment, the first heat exchanging part 16a is arranged in the first auxiliary machine module 22, but the arrangement place is not limited to this. For example, it may be in the second accessory module 23 or in the power generation unit 21.

The second heat exchanging unit 30b recovers heat in the exhaust gas of the combustion unit 30a from the heat medium or / and the hot water storage tank 19 to hot water flowing through the hot water supply line 19a, and the second heat exchange unit 30b distributes the exhaust gas from the combustion unit 30a. 2 on the exhaust gas flow path 62 and on the heat medium circulation flow path 55. The second heat exchange unit 30 b is disposed in the backup boiler 30. In the present embodiment, the heat recovery for the hot water supply line 19a and the heat recovery for the heat medium circulation passage 55 are performed by one heat exchange unit (here, the second heat exchange unit 30b). A heat exchange unit for the hot water supply line 19a may be provided separately.

In addition, the heat medium circulation channel 55 is provided with a bypass channel 17b provided so as to bypass the second heat exchange unit 30b. The bypass flow path 17b communicates the upstream and downstream of the second heat exchange unit 30b in the heat medium circulation flow path 55. Hereinafter, the heat medium circulation passage 55 that passes through the second heat exchange section 30b (does not bypass) is referred to as a heat exchange passage 17a. In addition, a switching valve 17 that switches the flow of the heat medium between the heat exchange flow path 17a and the bypass flow path 17b is provided in the merging portion on the upstream side of the bypass flow path 17b in the heat medium circulation flow path 55. .

The temperature measuring unit 18 measures the temperature in the housing 24. In the present embodiment, the temperature measuring unit 18 is arranged in the first auxiliary machine module 22, but the arrangement location is not limited to this. For example, it may be in the second accessory module 23 or in the power generation unit 21. The control unit 15 controls the fuel cell system 50, and here controls at least the operations of the cathode blower 26, the combustion unit blower 27, and the switching valve 17. Specifically, the control unit 15 operates the cathode blower 26 so that air having an air flow rate corresponding to the power generation amount of the cell stack 5 flows through the first branch flow path 51. In addition, the control unit 15 causes the combustion unit blower so that air flows through the second branch flow path 52 when the temperature in the casing 24 measured by the temperature measurement unit 18 exceeds a predetermined upper limit temperature. 27 is operated. Further, when the backup boiler 30 is operated, the control unit 15 operates the combustion unit blower 27 so that the air flow rate flowing through the second branch flow path 52 becomes the air flow rate necessary for the combustion of the combustion unit 30a.

Furthermore, when the backup boiler 30 is operating and the heat recovered from the second heat exchange unit 30b cannot be stored in the hot water storage tank 19, the control unit 15 switches so that the heat medium flows into the bypass channel 17b. The valve 17 is operated. Moreover, the control part 15 operates the switching valve 17 so that a heat medium may distribute | circulate to the bypass flow path 17b, when the backup boiler 30 has stopped.

The air introduced from the flue pipe T by operating the cathode blower 26 and / or the combustor blower 27 is a box 10a in which the power conditioner 10 is contained, a second auxiliary machine module 23a, a power generation unit 21a, Each of the first accessory module 22a is cooled while passing through the air inflow portion and the air outflow portion. Then, it reaches the branch point P and flows to the first branch channel 51 and / or the second branch channel 52.

In this embodiment, the system main body 20 and the backup boiler 30 are included in the outer case 56 with the upper surface of the system main body 20 and the lower surface of the backup boiler 30 in contact with each other. Further, a merged gas flow channel 57 formed by merging them is connected to the downstream side of the first and second exhaust

gas flow channels

61 and 62. The merged gas flow path 57 joins the exhaust gas from the cell stack 5 and the exhaust gas from the combustion unit 30 a and discharges the outer case 56 to the outside. Further, the configuration of the cathode blower 26, the combustion section blower 27, and the first and second

branch flow paths

51 and 52 in FIG. 5 is the configuration shown in FIG. 3, but the configuration of FIG. 2 or FIG. May be applied.

Next, an example of the operation of the fuel cell system 50 will be described with reference to FIGS. FIG. 6 is a flowchart showing an example of the operation when the control based on the temperature inside the casing is not performed in the fuel cell system of FIG. 5, and FIG. 7 is the case where the control based on the temperature inside the casing is performed in the fuel cell system of FIG. It is a flowchart which shows an example of operation | movement.

As shown in FIG. 6, when the operation control based on the temperature in the casing 24 is not performed, first, air is supplied to the second branch flow path 52 by the combustion section blower 27 and supplied from the hot water supply line 19a. It is determined whether or not there is a shortage of heat (heat demand for the combustion unit 30a) in the hot water (S1, S2). In the case of No in S2, the switching valve 17 is operated so that the heat medium flows through the bypass flow path 17b, and the backup boiler 30 is stopped (S3, S4). Thereby, a heat medium bypasses the 2nd heat exchange part 30b (S3). That is, when there is no shortage of heat in the hot water supplied from the hot water supply line 19a, air is circulated from the second branch flow path 52 to the combustion unit 30a without operating the backup boiler 30. And it transfers again to the determination process of said S2.

On the other hand, in the case of Yes in S2, it is further determined whether or not the hot water tank 19 is fully stored (a state where the heat storage amount has reached the upper limit) (S5). In the case of Yes in S5, the switching valve 17 is operated so that the heat medium flows into the bypass flow path 17b, and the heat medium bypasses the second heat exchange unit 30b (S6). On the other hand, in the case of No in S5, the switching valve 17 is operated so that the heat medium flows through the heat exchange flow path 17a, whereby the heat medium passes through the second heat exchange unit 30b and the exhaust gas from the combustion unit 30a. The heat is recovered to the heat medium (S7). Simultaneously with the execution of S6 or S7, the backup boiler 30 is operated (S8). That is, when there is a shortage of heat in the hot water supplied from the hot water supply line 19a, the combustion section blower 27 is set so that the amount of combustion air necessary for the operation of the backup boiler 30 flows through the second branch flow path 52. Control and operate the backup boiler 30. And it transfers again to the determination process of said S2.

Alternatively, as shown in FIG. 7, when performing the operation control based on the temperature in the housing 24, first, it is determined whether or not there is a shortage of heat in the hot water supplied from the hot water supply line 19a (S11). . In the case of Yes in S11, it is further determined whether or not the hot water tank 19 is fully stored (S12). In the case of Yes in S12, the switching valve 17 is operated so that the heat medium flows through the bypass flow path 17b, and thereby the heat medium bypasses the second heat exchange unit 30b (S13). On the other hand, in the case of No in S12, the switching valve 17 is operated so that the heat medium flows through the heat exchange flow path 17a, whereby the heat medium passes through the second heat exchange unit 30b and the exhaust gas from the combustion unit 30a. The heat is recovered into the heat medium (S14).

With the execution of S13 or S14, air is supplied to the second branch flow path 52 by the combustion section blower 27, and the backup boiler 30 is operated (S15, S16). That is, when there is a shortage of heat in the hot water supplied from the hot water supply line 19a, the combustion section blower 27 is set so that the amount of combustion air necessary for the operation of the backup boiler 30 flows through the second branch flow path 52. Control and operate the backup boiler 30. And it transfers again to the determination process of said S11.

On the other hand, in the case of No in S11, the temperature measurement unit 18 acquires the temperature R in the casing 24, and it is further determined whether or not the measured temperature R in the casing 24 exceeds the upper limit temperature Rmax. (S17). In the case of No in S17, the combustion section blower 27 is stopped and the air supply to the second branch flow path 52 is stopped (S18). In the case of Yes in S17 described above, the switching valve 17 is operated so that the heat medium flows into the bypass flow path 17b, whereby the heat medium bypasses the second heat exchange unit 30b (S19). And air is supplied to the 2nd branch flow path 52 by the blower 27 for combustion parts, and the backup boiler 30 is drive | operated (S20). At this time, the output of the combustion section blower 27 may be increased or decreased according to the acquired temperature R in the casing 24 to adjust the amount of air flowing through the second branch flow path 52.

The backup boiler 30 is stopped simultaneously with the execution of S18 or S20 (S21). That is, when there is no shortage of heat in the hot water supplied from the hot water supply line 19a and the temperature R in the housing 24 is higher than the upper limit temperature Rmax, the second boiler is not operated. Air is circulated from the branch flow path 52 to the combustion section 30a. And it transfers again to the determination process of said S11.

As described above, also in this embodiment, the same effects as those of the first embodiment are obtained. Furthermore, in the present embodiment, the cathode blower 26 is operated so that air having an air flow rate corresponding to the power generation amount of the fuel cell system 50 flows through the first branch flow path 51. Therefore, air always flows through the first branch channel 51 when the fuel cell system 50 generates power.

In this embodiment, when the temperature in the casing 24 exceeds the upper limit temperature Rmax, the combustion section blower 27 is operated so that air flows through the second branch flow path 52. Therefore, when the temperature in the housing 24 is high, air can be circulated through the second branch flow path 52.

In the present embodiment, when the backup boiler 30 is operated (actuated), the combustion unit blower 27 operates so that the air flow rate flowing through the second branch flow path 52 becomes the air flow rate necessary for the combustion of the combustion unit 30a. Is done. Therefore, it is possible to control the air flow rate of the second branch flow path 52 as being dominant for the combustion of the combustion unit 30a.

Further, in the present embodiment, the backup medium 30 is in operation, and the heat medium flows through the bypass flow path 17b during full storage when the heat recovered from the second heat exchange unit 30b cannot be stored in the hot water storage tank 19. The switching valve 17 can be switched to.

In the present embodiment, as described above, when the backup boiler 30 is stopped, the switching valve 17 can be switched so that the heat medium flows into the bypass flow path 17b. As a result, it is possible to suppress heat from being deprived from the heat medium passing through the second heat exchange unit 30b.

FIG. 8 is a schematic block diagram showing a main part in a modification of the fuel cell system shown in FIG. The fuel cell system 50 of the present embodiment can also employ the configuration shown in FIG. Specifically, components with high cooling priority (auxiliary module, power conditioner, power generation unit, etc.) are preferentially installed below the system body, and the entire surface or one of the plates or boxes on which the components are arranged. You may form the surface of a part with the member (for example, net | network or a punching board) which can ventilate. The air introduced from the flue pipe T cools the inside of the system main body 20, and the air itself rises toward the upper side of the system main body 20 while being heated. And it distribute | circulates to the 1st branch flow path 51 or / and the 2nd branch flow path 52. FIG. The configuration of the cathode blower 26, the combustion section blower 27, and the first and second

branch flow paths

51 and 52 in FIG. 8 is the configuration shown in FIG. 4, but the configuration of FIG. 2 or FIG. 3 is applied. May be. Further, in place of the combustion section blower 27, the above-described combined blower 28 may be provided.

The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments. The present invention is modified without departing from the scope described in the claims or applied to others. It may be.

For example, in the said embodiment, although the air flow path was formed in the order of the power conditioner 10, the 2nd auxiliary machine module 23, the electric power generation part 21, and the 1st auxiliary machine module, the order and auxiliary machine which form an air flow path are changed. The number of compartments such as modules to be stored is not limited to this. It can be arbitrarily determined in consideration of the priority of arrangement of components constituting the fuel cell system or the cooling priority.

Moreover, in the said embodiment, although outdoor air is distribute | circulated in the housing | casing 24 via the flue pipe T, when indoor air is distribute | circulated in the housing | casing 24 as external air, the flue pipe T Is no longer necessary. Moreover, although the said embodiment is equipped with the backup boiler 30 as a heat supply part, the heat supply part should just be for supplying heat quantity according to a heat demand, for example, a normal boiler (main boiler) May be included).

Moreover, in the said embodiment, although the air is distribute | circulated in the module by the air flow path 25, the air flow path 25 touches the outer surface (outer wall of

box

10a, 21a, 22a, 23a) of a module. Air may be circulated, thereby cooling the module (cooling the outer surface). Further, the first gas flow path 61 and the second gas flow path 62 do not necessarily have to be merged, and may be independently discharged outside the outer case 56. In the above description, the “module” means, for example, one in which one or a plurality of elements (parts or devices) are aggregated in terms of function or configuration as a function for realizing a predetermined function.

In the second embodiment, a heat exchanging part provided on the merged gas flow path 57 may be provided instead of the first and second

heat exchanging parts

16a and 30b. That is, the heat exchange part that recovers the heat discharged from the combustion part can also serve as the heat exchange part that recovers the heat discharged from the power generation part.

In the heat medium circulation channel 55 of the second embodiment, the heat exchange of the second heat exchange unit 30b is performed after the heat exchange of the first heat exchange unit 16a. However, when a plurality of heat exchange units are provided, the heat recovery order on the heat medium circulation channel is not limited. In the second embodiment, for example, when a hot water storage tank 19 having a high heat recovery rate is used, the second heat exchange unit 30b, the bypass flow path 17b, and the switching valve 17 are not necessary.

According to the present invention, the inside of the housing can be sufficiently cooled.

DESCRIPTION OF SYMBOLS 1 ... Fuel cell system, 5 ... Cell stack, 10 ... Power conditioner (control part, apparatus), 15 ... Control part, 17 ... Switching valve, 17b ... Bypass flow path, 18 ... Temperature measurement part, 19 ... Hot water storage tank, 20 ... System body, 21 ... Power generation unit (equipment), 22 ... First auxiliary equipment module (equipment), 23 ... First auxiliary equipment module (equipment), 24 ... Case, 25 ... Air flow path, 26 ... Cathode blower ( First blower), 27 ... Blower for combustion section (second blower), 28 ... Blower (first and second blower), 30 ... Backup boiler (heat supply section), 30a ... Combustion section, 30b ... 2nd heat exchange part (heat exchange part), 51 ... 1st branch flow path, 52 ... 2nd branch flow path, 53 ... Manifold part, 55 ... Heat-medium circulation flow path, P ... Branch location.

Claims

A system main body including a power generation unit including a cell stack that generates power using a hydrogen-containing gas, and a housing that houses the power generation unit;
A heat supply part for including a combustion part inside and supplying heat according to heat demand;
An external air flow in the housing to cool the inside of the housing, and
On the downstream side of the air flow path, a first branch flow path that supplies the air to the cell stack of the power generation unit, a second branch flow path that supplies the air to the combustion unit of the heat supply unit, Including
In the air flow path, a first air blowing unit that pumps the air toward the cell stack of the power generation unit, a second air blowing unit that pumps the air toward the combustion unit of the heat supply unit, and A fuel cell system provided with
A control unit for controlling the fuel cell system;
2. The fuel cell system according to claim 1, wherein the control unit operates the first air blowing unit so that air having an air flow rate according to the power generation amount of the fuel cell system flows through the first branch flow path.
The fuel cell system according to claim 2, wherein the control unit operates the second air blowing unit so that air flows through the second branch flow path.
A temperature measuring unit for measuring the temperature in the housing;
3. The fuel according to claim 2, wherein the control unit operates the second air blowing unit so that air flows through the second branch flow path when the temperature in the housing exceeds a predetermined upper limit temperature. 4. Battery system.
The said control part operates the said 2nd ventilation part so that the air flow volume distribute | circulated to the said 2nd branch flow path may turn into the air flow rate required for the combustion of the said combustion part, when operating the said heat supply part. The fuel cell system according to any one of 2 to 4.
A hot water storage tank that stores heat recovered from the fuel cell system in water stored inside, and discharges the water according to demand,
A heat medium circulation passage for circulating a heat medium between the hot water storage tank and the fuel cell system;
A heat exchange section provided in the heat medium circulation channel so as to recover heat from the exhaust heat discharged from the heat supply section;
A bypass flow path for communicating the upstream of the heat exchange section and the downstream of the heat exchange section in the heat medium circulation flow path so as to bypass the heat exchange section;
A switching valve that is provided in the heat medium circulation flow path and switches the flow of the heat medium in the bypass flow path;
The controller is
The said switching valve is operated so that the said heat medium distribute | circulates to the said bypass flow path when the said heat supply part is operate | moving and the heat | fever collect | recovered from the said heat exchange part cannot be stored in the said hot water storage tank. 6. The fuel cell system according to any one of 2 to 5.
The fuel cell system according to claim 6, wherein when the heat supply unit is stopped, the control unit operates the switching valve so that the heat medium flows through the bypass flow path.
A cathode blower provided in the first branch flow path and constituting the first air blowing section;
The fuel cell system according to any one of claims 1 to 7, further comprising a combustion section blower provided in the second branch flow path and constituting the second blower section.
A cathode blower provided in the first branch flow path and constituting the first air blowing section;
7. The air blower according to claim 1, further comprising: a dual-purpose blower that is provided upstream of a branching location of the first and second branch channels and that constitutes the first and second air blowing units. The fuel cell system according to one item.
The fuel cell system according to any one of claims 1 to 9, wherein a manifold portion is provided at a branch point of the first and second branch channels in the air channel.
The fuel cell system according to any one of claims 1 to 10, wherein the air flow channel circulates the air so as to cool a plurality of devices in the casing in order of a low operation guarantee temperature.