JP2021018943A - Fuel cell system - Google Patents

Abstract

To obtain a fuel cell system capable of increasing the amount of condensed water produced by an increase instruction to increase the amount of condensed water produced by a user.SOLUTION: A fuel cell is supplied with fuel, air supplied by using an air control unit, and reformed water for reforming the fuel to generate electricity. An exhaust heat exchange unit cools an exhaust gas discharged from the fuel cell with a refrigerant to generate condensed water. The control device increases the amount of heat exchange between the exhaust gas and the refrigerant at least by a user's instruction to increase the amount of condensed water produced.SELECTED DRAWING: Figure 1

Description

The present invention relates to a fuel cell system that generates electricity using gas.

There is a fuel cell system that obtains condensed water from the exhaust as it generates electricity.

JP-A-2014-229402

Conventionally, exhaust gas discharged from a fuel cell is cooled by a refrigerant to generate condensed water, and this condensed water is used as reforming water used for power generation of a fuel cell. However, most of the condensed water is used as reformed water and there is almost no surplus water. Therefore, when it becomes difficult to secure miscellaneous water in a house due to a disaster, for example, this condensed water cannot be used as miscellaneous water.

An object of the present invention is to increase the amount of condensed water produced by a user's instruction to increase the amount of condensed water produced.

The fuel cell system according to the first aspect includes a fuel cell to generate power by supplying fuel, air supplied by using an air control unit, and reformed water for reforming the fuel, and exhaust gas from the fuel cell. Heat exchange between the exhaust gas and the refrigerant by an exhaust heat exchange unit that cools the exhaust water with a refrigerant to generate condensed water, a cooling unit that cools the refrigerant, and at least an increase instruction for increasing the amount of condensed water generated by the user. It is characterized by having a control device that increases the amount.

According to this configuration, the control device increases the amount of heat exchange between the exhaust gas and the refrigerant, at least by the user's instruction to increase the amount of condensed water produced.

As the control device increases the amount of heat exchange between the exhaust gas and the refrigerant, the amount of condensed water generated by the heat exchange with the refrigerant increases.

In this way, the amount of condensed water produced can be increased by the user's instruction to increase the amount of condensed water produced.

The fuel cell system according to the second aspect has a reformed water storage unit that stores the condensed water as the reformed water in the fuel cell system according to the first aspect, and is stored in the reformed water storage unit. It has a water amount sensor that detects the amount of reformed water, and when the amount of reformed water detected by the water amount sensor becomes less than a predetermined reference value, the control device uses the exhaust gas and the refrigerant. It is characterized by increasing the amount of heat exchange of.

According to this configuration, when the amount of reformed water detected by the water amount sensor becomes less than a predetermined reference value, the control device increases the amount of heat exchange between the exhaust gas and the refrigerant. As a result, the condensed water can supply the reformed water supplied to the fuel cell.

The fuel cell system according to the third aspect is characterized in that, in the fuel cell system according to the first or second aspect, it has an input unit capable of inputting an increase instruction for increasing the amount of condensed water generated from the user. ..

According to this configuration, the user can increase the amount of condensed water generated by inputting an increase instruction for increasing the amount of condensed water generated to the input unit.

The fuel cell system according to the fourth aspect is the circulation unit that circulates the refrigerant so that the refrigerant passes through the exhaust heat exchange unit in the fuel cell system according to any one of the first to third aspects. The control device controls the cooling unit to increase the cooling amount of the refrigerant, and controls the circulation unit to increase the amount of the refrigerant passing through the exhaust heat exchange unit per unit time. And, controlling the air control unit to reduce the amount of air supplied to the fuel cell, at least one of them is executed to increase the amount of heat exchange between the exhaust gas and the refrigerant. ..

According to this configuration, the control device controls the cooling unit to increase the cooling amount of the refrigerant, controls the circulation unit to increase the amount of the refrigerant passing through the exhaust heat exchange unit per unit time, and air control. Control the unit to reduce the amount of air supplied to the fuel cell, at least one of which is performed to increase the amount of heat exchange between the exhaust gas and the refrigerant.

In this way, the control device can increase the amount of condensed water generated by controlling at least one of the cooling unit, the circulation unit, and the air control unit.

The fuel cell system according to the fifth aspect is the fuel cell system according to the fourth aspect, wherein the control device controls the cooling unit to increase the cooling amount of the refrigerant, and controls the circulation unit. Increasing the amount of refrigerant passing through the exhaust heat exchange unit per hour, and controlling the air control unit to reduce the amount of air supplied to the fuel cell are all executed to perform the exhaust gas and the above. It is characterized by increasing the amount of heat exchange with the refrigerant.

According to this configuration, the control device controls the cooling unit to increase the cooling amount of the refrigerant, controls the circulation unit to increase the amount of the refrigerant passing through the exhaust heat exchange unit per unit time, and air control. The unit is controlled to reduce the amount of air supplied to the fuel cell, all of which are performed to increase the amount of heat exchange between the exhaust gas and the refrigerant.

As a result, the amount of condensed water produced can be increased as compared with the case where the control device executes only one of them.

In the fuel cell system according to the sixth aspect, in the fuel cell system according to any one of the first to fifth aspects, the refrigerant circulates with the exhaust heat exchange unit and the refrigerant is stored. In the pressurized refrigerant storage section, the first flow path member through which the clean water warmed by the refrigerant storage section flows, the second flow path member through which the clean water supplied to the refrigerant storage section flows, and the refrigerant storage section. A first blocking member that blocks the warmed clean water from flowing through the first flow path member, and a second blocking member that blocks the clean water supplied to the refrigerant storage unit from flowing through the second flow path member. And, characterized by having.

According to this configuration, the first blocking member blocks the flow of clean water warmed by the refrigerant storage section, and the second blocking member blocks the flow of clean water supplied to the refrigerant storage section. As a result, the pressure holding state of the pressurized refrigerant storage unit can be maintained even when the water supply is cut off when clean water is not supplied from the outside.

The fuel cell system according to the seventh aspect is the fuel cell system according to the sixth aspect, characterized by claim 7 copy.

According to this configuration, the control device controls the first blocking member and blocks the clean water warmed by the refrigerant storage part from flowing through the first flow path member by the increase instruction for increasing the amount of condensed water generated by the user. Then, the second blocking member is controlled to block the clean water supplied to the refrigerant storage unit from flowing through the second flow path member. As a result, the flow of clean water can be blocked without the user operating the first blocking member and the second blocking member.

In this aspect, it is possible to obtain a fuel cell system capable of increasing the amount of condensed water produced, if necessary.

It is a schematic block diagram which showed the fuel cell system which concerns on 1st Embodiment of this invention. It is a schematic block diagram which showed the fuel cell module provided in the fuel cell system which concerns on 1st Embodiment of this invention. It is a block diagram which showed the control system of the control device provided in the fuel cell system which concerns on 1st Embodiment of this invention. It is a block diagram which showed the reforming water tank, the water amount sensor, and the discharge mechanism provided in the fuel cell system which concerns on 1st Embodiment of this invention. FIG. 5 is a flow chart showing a step of shifting from a normal mode to an increasing mode or from an increasing mode to a normal mode in the fuel cell system according to the first embodiment of the present invention. It is a block diagram which showed the reforming water tank, the water amount sensor, and the discharge mechanism provided in the fuel cell system which concerns on 2nd Embodiment of this invention. It is a block diagram which showed the reforming water tank, the water amount sensor, and the discharge mechanism provided in the fuel cell system which concerns on 3rd Embodiment of this invention. (A) (B) It is a block diagram which showed the refrigerant tank, the clean water heat exchanger and the like provided in the fuel cell system which concerns on 4th Embodiment of this invention.

<First Embodiment>
The fuel cell system 10 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 5. The fuel cell system 10 of the present embodiment is used in a house as an example. The arrow UP shown in each figure indicates the upper part in the vertical direction.

As shown in FIG. 1, the fuel cell system 10 includes a fuel cell unit 12 with a refrigerant tank (hereinafter, “battery unit 12”)) and a backup heat source unit (not shown) that is separate from the battery unit 12. Hereinafter, it is composed of two units (“heat source unit)”). Further, the fuel cell system 10 includes a control device 70 that controls various electrical components provided in the fuel cell system 10. As an example, the battery unit 12 and the heat source unit 14 can be installed on a foundation made of concrete or the like outdoors, or on a veranda or the like.

(Configuration of battery unit 12)
Inside the housing 16 of the battery unit 12, a power generation unit 17 that generates electricity and discharges exhaust gas, a refrigerant heating unit 19 that heats the refrigerant W2 with the exhaust gas, and a clean water heating unit 21 that heats the clean water with the refrigerant W2. Is provided.

-Power generation unit 17-
The power generation unit 17 includes a fuel cell module 18 (hereinafter referred to as “battery module 18”) to which city gas, air (oxygen) and reformed water W1 are supplied to generate electricity, and a fuel gas pipe for supplying city gas to the battery module 18. It has 20 and. Further, the power generation unit 17 is provided in the middle portion of the fuel gas pipe 20 and stores a desulfurizer 22 for removing sulfur compounds contained in the city gas and a reformed water tank for storing the reformed water W1 supplied to the battery module 18. 24, a water amount sensor 214 for detecting the amount of reformed water W1 in the reformed water tank 24, and a take-out mechanism 220 for taking out the reformed water W1 stored in the reformed water tank 24 to the outside are provided. Further, the power generation unit 17 includes an input unit 210 that allows the user to input an increase instruction for increasing the amount of condensed water generated by the remote controller. The details of the input unit 210, the reforming water tank 24, the water amount sensor 214, and the take-out mechanism 220 will be described later.

Further, the power generation unit 17 is provided in the intermediate portion between the reforming water supply pipe 26 connecting the reforming water tank 24 and the battery module 18 and the reforming water supply pipe 26, and the reforming water of the reforming water tank 24 is provided. It is provided with a reforming water pump 28 for supplying W1 to the battery module 18. Further, the power generation unit 17 is provided with a wiring 66 for transmitting the electric power generated by the battery module 18 to the outside, an inverter 68 provided in the middle portion of the wiring 66 and converting DC power into AC power, and an air blower 86. The oxide gas tube 88 is provided. The air blower 86 is an example of an air control unit.

-Refrigerant heating unit 19-
The refrigerant heating unit 19 includes a refrigerant tank 30 for storing the refrigerant W2, an exhaust heat exchanger 31 for exchanging heat between the exhaust gas discharged from the battery module 18 and the refrigerant W2, and a battery module 18 and an exhaust heat exchanger. It is provided with a first exhaust gas pipe 32 that connects to 31. Further, the refrigerant heating unit 19 is a drain pipe for discharging the moisture generated inside the exhaust heat exchanger 31 (moisture in the exhaust gas condensed inside the exhaust heat exchanger 31) to the reformed water tank 24. A second exhaust gas pipe 34 for branching from the middle of the drain pipe 35 and discharging the exhaust gas that has passed through the exhaust heat exchanger 31 to the outside of the housing 16 is provided. Further, the refrigerant heating unit 19 is provided with a pipe 36 for connecting the bottom of the refrigerant tank 30 and the exhaust heat exchanger 31 and supplying the refrigerant W2 of the refrigerant tank 30 to the exhaust heat exchanger 31.

Further, the refrigerant heating unit 19 connects the ceiling wall 30a of the refrigerant tank 30 and the exhaust heat exchanger 31, and a pipe 38 and a pipe 38 for returning the refrigerant W2 that has passed through the exhaust heat exchanger 31 to the refrigerant tank 30. It is provided with a temperature sensor 37 which is arranged in the middle of the above and detects the temperature of the refrigerant W2 returned to the refrigerant tank 30.

Further, the refrigerant heating unit 19 is provided in the pipe 36 to send the refrigerant W2 of the refrigerant tank 30 to the exhaust heat exchanger 31 side, and the heat recovery pump 40 provided in the pipe 36 to send the heat of the refrigerant W2 to the outside. It is provided with a cooling unit 42 provided with a radiator or the like capable of discharging. The heat recovery pump 40 is an example of a circulation unit, and the exhaust heat exchanger 31 is an example of an exhaust heat exchange unit.

In this embodiment, water (tap water or the like as an example) is used as the refrigerant W2 of the refrigerant tank 30.

Further, the ceiling wall 30a of the refrigerant tank 30 is not formed with an opening, and the refrigerant tank 30 is a pressurized tank filled with the refrigerant W2.

As described above, a path through which the refrigerant W2 circulates between the refrigerant tank 30 and the exhaust heat exchanger 31, that is, a first circulation path 118 is formed in the pipes 36 and 38 inside the housing 16. Has been done.

-Water heating unit 21-
The end of the clean water heating unit 21 is connected to a portion on the lower end side of the refrigerant tank 30 in order to exchange heat between the refrigerant W2 of the refrigerant tank 30 and the clean water supplied from the outside of the housing 16. It is provided with a water pipe 52 and a discharge pipe 54 whose end is connected to a portion on the upper end side of the refrigerant tank 30.

The water pipe 52 is a pipe that supplies clean water from the outside of the housing 16 to 30, and the discharge pipe 54 is a pipe that discharges the clean water warmed by the refrigerant tank 30 to the outside of the housing 16.

Further, a blocking member 56 for blocking the flow of clean water is arranged in the middle of the water pipe 52, and a blocking member 58 for blocking the flow of clean water is arranged in the middle of the discharge pipe 54. Further, the clean water heating unit 21 includes a portion of the clean water pipe 52 on the upstream side of the shutoff member 56 in the flow direction of clean water and a drainage pipe 54 on the downstream side of the cutoff member 58 in the flow direction of clean water. A connecting pipe 60 is provided to connect the portion of the above.

(Structure of battery module 18)
Next, the battery module 18 provided in the power generation unit 17 will be specifically described. As shown in FIG. 2, a reforming catalyst 72, a burner 74, and a fuel cell stack 76 are provided inside the housing 71 of the battery module 18. The battery module 18 is an example of a fuel cell.

The reforming catalyst 72 is connected to the fuel gas pipe 20. To the reforming catalyst 72, city gas from which the sulfur compound is adsorbed and removed by the desulfurizer 22 is supplied through the fuel gas pipe 20. The reforming catalyst 72 steam reforms the supplied city gas (raw material gas) using the reformed water (condensed water) W1 supplied through the reformed water supply pipe 26.

A stack exhaust gas pipe 80, which will be described later, is connected to the burner 74. The burner 74 burns the burner gas (stack exhaust gas containing unreacted hydrogen gas) supplied through the stack exhaust gas pipe 80 to heat the reforming catalyst 72. Then, in the reforming catalyst 72, a fuel gas containing hydrogen gas is generated from the city gas (raw material gas) supplied from the desulfurization device 22. This fuel gas is supplied to the fuel pole 78 of the fuel cell stack 76, which will be described later, through the fuel gas pipe 75.

The fuel cell stack 76 is a solid oxide fuel cell stack, and has a plurality of stacked fuel cell cells 81 (only one is shown in FIG. 2). Each fuel cell 81 has an electrolyte layer 82, and fuel poles 78 and air poles 84 laminated on the front and back surfaces of the electrolyte layer 82, respectively.

Oxidizing gas (air outside the housing 16) is supplied to the air electrode 84 (cathode electrode) through an oxidizing gas pipe 88 provided with an air blower 86. In the air electrode 84, as represented by the following formula (1), oxygen in the oxidizing gas reacts with the electrons generated in the fuel electrode 78 described later to generate oxygen ions. The oxygen ions reach the fuel electrode 78 through the electrolyte layer 82.

(Air pole reaction)
^{_{1 / 2O 2 + 2e - →}} O 2- ··· (1)

On the other hand, in the fuel electrode 78, as represented by the following formulas (2) and (3), oxygen ions passing through the electrolyte layer 82 react with hydrogen and carbon monoxide in the fuel gas, and water (water vapor). And carbon dioxide and electrons are generated. The electrons generated at the fuel pole 78 reach the air pole 84 through an external circuit. Then, the electrons move from the fuel pole 78 to the air pole 84 in this way, so that power is generated in each fuel cell 81. Further, each fuel cell 81 generates heat during power generation due to the above reaction.

(Fuel electrode reaction)
^{_{H 2 + O 2- → H 2}} O + 2e - ··· (2)
^{_{CO + O 2- → CO 2 +}} 2e - ··· (3)

The upstream side of the stack exhaust gas pipe 80 connected to the fuel cell stack 76 is branched into a fuel electrode exhaust gas pipe 90 and an air electrode exhaust gas pipe 92, and the fuel electrode exhaust gas pipe 90 and the air electrode exhaust gas pipe 92 are fuel poles. It is connected to 78 and an air electrode 84, respectively. The fuel electrode exhaust gas discharged from the fuel electrode 78 and the air electrode exhaust gas discharged from the air electrode 84 are discharged through the fuel electrode exhaust gas pipe 90 and the air electrode exhaust gas pipe 92, and are mixed in the stack exhaust gas pipe 80. It is made into stack exhaust gas. This stack exhaust gas contains unreacted hydrogen gas contained in the fuel electrode exhaust gas, and is supplied to the burner 74 as burner gas as described above. A first exhaust gas pipe 32 for discharging the burner exhaust gas to the exhaust heat exchanger 31 is connected to the burner 74.

(Control device 70)
As shown in FIG. 3, the control device 70 is supplied with system power or power from the inverter 68, and includes electrical components of the battery unit 12, such as a reforming water pump 28, a heat recovery pump 40, and a cooling unit 42. Take control.

(Action)
Next, the operation of the fuel cell system 10 of the present embodiment will be described.
In the fuel cell system 10, fuel gas is supplied from the reforming catalyst 72 shown in FIG. 2 to the fuel pole 78 of the fuel cell stack 76, and the air blower 86 operates to release air as oxide gas from the oxide gas pipe 88. It is supplied to the air electrode 84 of the fuel cell stack 76. As a result, the fuel gas and the oxide gas react in the fuel cell stack 76 to generate electricity.

Along with this power generation, a stack exhaust gas containing unreacted hydrogen gas is discharged from the fuel cell stack 76, and the stack exhaust gas is burned in the burner 74 as a burner gas. Burner exhaust gas is discharged from the burner 74. This burner exhaust gas contains water vapor and is supplied to the exhaust heat exchanger 31 through the first exhaust gas pipe 32 shown in FIG.

In the exhaust heat exchanger 31, heat exchange is performed between the burner exhaust gas and the refrigerant W2 supplied from the refrigerant tank 30, the refrigerant W2 is heated, and the water vapor contained in the burner exhaust gas is condensed. The condensed water (distilled water) generated in the exhaust heat exchanger 31 is collected in the reformed water tank 24 as reformed water W1. The reformed water W1 recovered in the reformed water tank 24 is supplied to the reforming catalyst 72 through the reforming water supply pipe 26, and is used as steam for steam reforming in the reforming catalyst 72 shown in FIG. .. The burner exhaust gas from which the water has been removed is discharged to the outside through the second exhaust gas pipe 34.

Further, by operating the heat recovery pump 40 shown in FIG. 1, the first circulation path 118 circulates the refrigerant W2 between the refrigerant tank 30 and the exhaust heat exchanger 31. Therefore, the lower refrigerant W2 in the refrigerant tank 30 is supplied to the exhaust heat exchanger 31 via the pipe 36, is heated by the exhaust heat exchanger 31, and then returns to the upper side of the refrigerant tank 30, thereby causing the refrigerant. The temperature of the refrigerant W2 in the tank gradually rises from the upper side to the lower side.

Here, in the fuel cell system 10, the reformed water W1 used for power generation is recovered from the burner exhaust gas containing water vapor, so that it is necessary to cool the burner exhaust gas. At that time, in order to recover a sufficient amount of water, it is necessary to cool the burner exhaust gas to a certain temperature (for example, 47 ° C.) or less.

To cool the burner exhaust gas, a method of exchanging heat with heat recovery water (refrigerant W2) is used. For example, when power is being generated and hot water is used in a small amount, the refrigerant tank 30 becomes full. When the heat recovery water temperature rises due to such a situation, the burner exhaust gas cannot be sufficiently cooled, and a sufficient amount of reformed water W1 cannot be secured. Therefore, it is necessary to keep the temperature of the heat recovery water below a certain level (for example, 44 ° C), and a cooling unit 42 that can release the heat of the refrigerant W2 to the outside is arranged in the pipe 36, and the refrigerant W2 is required. Cool down.

Further, when the user opens a faucet (not shown) and requests hot water, the refrigerant W2 of the warmed refrigerant tank 30 exchanges heat with the clean water supplied from the outside in the refrigerant tank 30. .. Further, the clean water warmed in the refrigerant tank 30 flows through the discharge pipe 54 and is discharged to the outside of the housing 16 to be discharged.

When it is not necessary to heat the clean water, the blocking members 56 and 58 block the flow of the clean water, and the clean water flows through the connecting pipe 60 and is discharged to the outside of the housing 16.

(Main part composition)
Next, the input unit 210, the reforming water tank 24, the water amount sensor 214, the take-out mechanism 220, and the configuration in which the control device 70 controls each unit by receiving an increase signal for increasing the amount of condensed water generated will be described.

-Input unit 210-
The input unit 210 is outside the housing 16 as shown in FIG. 1 so that the user can input an increase instruction for increasing the amount of condensed water generated and an operation instruction for operating the take-out pump 224, which will be described later, with the remote controller. It is located in.

In this configuration, when an increase instruction for increasing the amount of condensed water produced is input to the input unit 210 by the user, the control device 70 receives an increase signal for increasing the amount of condensed water produced. Upon receiving this increase signal, the amount of condensed water generated increases, and the increased condensed water is supplied from the housing 16 to the outside, which will be described in detail later. Then, the supplied water is used as miscellaneous water by the user.

-Modified water tank 24, water volume sensor 214-
As shown in FIG. 4, the reforming water tank 24 has a box shape with an open upper part. The water amount sensor 214 is, for example, a capacitance type water amount sensor, which detects the amount of reformed water W1 by detecting the water level of the reformed water W1.

In this configuration, the control device 70 acquires the amount of reformed water W1 in the reformed water tank 24 based on the detection result of the water amount sensor 214. Specifically, the control device 70 determines that the reformed water W1 has not reached or exceeded the reference value K1 (see FIG. 4) required to operate the power generation unit 17 based on the detection result of the water amount sensor 214. To get. When the amount of reformed water W1 in the reformed water tank 24 is less than the reference value K1, the control device 70 receives an increase signal that increases the amount of condensed water produced. Upon receiving this increase signal, the amount of condensed water produced increases, and the increased condensed water causes the reformed water W1 in the reforming water tank 24 to reach the reference value K1, which will be described in detail later.

− Extraction mechanism 220−
As shown in FIG. 4, the take-out mechanism 220 includes a take-out pipe 222, a take-out pump 224, and a take-out port 228.

The take-out pipe 222 has an L-shape, and has a horizontal portion 222a extending in the horizontal direction and a vertical portion 222b extending in the vertical direction. One end of the horizontal portion 222a is attached to an upper portion of the reference value K1 on the outside of the side plate 24a of the reforming water tank 24. Specifically, one end of the horizontal portion 222a is attached to the outside of the side plate 24a of the reforming water tank 24 so that the reforming water W1 exceeding the reference value K1 flows into the horizontal portion 222a. Further, the vertical portion 222b extends downward from the other end of the horizontal portion 222a, and the lower end of the vertical portion 222b reaches the bottom plate 16a of the housing 16.

The take-out pump 224 is provided in the horizontal portion 222a of the take-out pipe 222, and the reforming water W1 stored in the reforming water tank 24 is taken out from the reforming water tank 24. The take-out port 228 is attached to the lower end of the vertical portion 222b of the take-out pipe 222, and the lower end of the vertical portion 222b is attached to the bottom plate 16a of the housing 16.

In this configuration, when the amount of reformed water W1 stored in the reformed water tank 24 exceeds the reference value K1, when an operation instruction for operating the take-out pump 224 is input to the input unit 210, take-out is performed. The pump 224 takes out the reforming water W1 stored in the reforming water tank 24 from the reforming water tank 24. Further, the reforming water W1 taken out from the reforming water tank 24 flows through the take-out pipe 222, flows through the take-out port 228, and is supplied to the outside from the housing 16.

-Control device 70-
When the control device 70 shown in FIG. 3 does not receive an increase signal that increases the amount of condensed water produced, the amount of condensed water generated by the exhaust heat exchanger 31 is supplied to the battery module 18 for modification. Each part of the battery unit 12 is controlled in a normal mode determined based only on the amount of water W1.

Further, when the control device 70 receives the increase signal described above, the control device 70 switches the battery unit 12 from the normal mode to the increase mode in which the condensed water is increased. Specifically, the control device 70 controls the heat recovery pump 40, the cooling unit 42, and the air blower 86 to increase the condensed water. The details of the control of each part of the control device 70 will be described together with the operation of the main part configuration described later.

(Action of main part composition)
The operation of the main part configuration will be described together with the flow chart shown in FIG.

When the fuel cell system 10 is operated, in step S100, the control device 70 operates the battery unit 12 in the normal mode. In the normal mode, the take-out pump 224 is not operating.

Next, in step S200, it is determined whether or not the control device 70 has received an increase signal that increases the amount of condensed water produced. Specifically, the control device 70 is instructed to increase the amount of condensed water generated from the user when the amount of reformed water W1 stored in the reformed water tank 24 is less than the reference value K1. When input to the input unit 210, it receives an increase signal that increases the amount of condensed water produced.

When the increase signal is received, the process proceeds to step S300, and when it is determined that the increase signal is not received, the control device 70 makes the above-mentioned determination again in step S200. That is, if no increase signal is received, the normal mode is continued.

Next, in step S300, the control device 70 switches the battery unit 12 from the normal mode to the increasing mode in which the condensed water is increased. Specifically, the control device 70 controls the cooling unit 42 shown in FIG. 1 and increases the momentum of the cooling unit 42 to increase the cooling amount of the refrigerant W2. In the present embodiment, as an example, the momentum of the cooling unit 42 is increased by 20% from the momentum in the normal mode.

By increasing the momentum of the cooling unit 42, the temperature of the refrigerant W2 supplied to the exhaust heat exchanger 31 is lowered with respect to the temperature in the normal mode. As the temperature of the refrigerant W2 decreases, the amount of heat exchange between the burner exhaust gas and the refrigerant W2 in the exhaust heat exchanger 31 increases. As the amount of heat exchange between the burner exhaust gas and the refrigerant W2 increases, the condensed water generated in the exhaust heat exchanger 31 increases and is recovered in the reformed water tank 24 as reformed water W1.

Further, the control device 70 increases the rotation speed of the heat recovery pump 40 shown in FIG. In other words, the control device 70 increases the amount of refrigerant W2 passing through the exhaust heat exchanger 31 per unit time. In the present embodiment, as an example, the rotation speed of the heat recovery pump 40 is increased by 20% from the rotation speed in the normal mode.

By increasing the rotation speed of the heat recovery pump 40, the amount of the refrigerant W2 passing through the exhaust heat exchanger 31 per unit time increases. As the amount of the refrigerant W2 passing through the exhaust heat exchanger 31 increases, the amount of heat exchange between the burner exhaust gas and the refrigerant W2 in the exhaust heat exchanger 31 increases. As the amount of heat exchange between the burner exhaust gas and the refrigerant W2 increases, the condensed water generated in the exhaust heat exchanger 31 increases and is recovered in the reformed water tank 24 as reformed water W1.

Further, the control device 70 reduces the rotation speed of the air blower 86 shown in FIG. In other words, the control device 70 reduces the amount of air supplied to the air electrode 84 of the fuel cell stack 76. In the present embodiment, as an example, the rotation speed of the air blower 86 is reduced by 20% from the rotation speed in the normal mode.

By reducing the rotation speed of the air blower 86, the amount of air supplied to the air electrode 84 of the fuel cell stack 76 shown in FIG. 2 is reduced. As a result, the dew point of the burner exhaust gas rises. That is, the temperature at which the water vapor contained in the burner exhaust gas condenses rises.

As the temperature at which the water vapor contained in the burner exhaust gas condenses rises, the amount of heat exchange between the burner exhaust gas and the refrigerant W2 in the exhaust heat exchanger 31 increases. As the amount of heat exchange between the burner exhaust gas and the refrigerant W2 increases, the condensed water generated in the exhaust heat exchanger 31 increases and is recovered in the reformed water tank 24 as reformed water W1.

Then, the take-out pump 224 takes out the reforming water W1 exceeding the reference value K1 from the reforming water tank 24. The reforming water W1 taken out from the reforming water tank 24 flows through the take-out pipe 222, flows through the take-out port 228, and is supplied to the outside from the housing 16. Then, the water supplied to the outside is used by the user.

Next, in step S400, the control device 70 determines whether or not the increase signal that increases the amount of condensed water produced has been cancelled. Specifically, the control device 70 increases the amount of condensed water generated from the user when the amount of reformed water W1 stored in the reformed water tank 24 reaches the reference value K1. When the cancellation of the instruction is input to the input unit 210, it is determined that the increase signal has been canceled.

If it is determined that the increase signal has disappeared, the process proceeds to step S500, and if it is determined that the increase signal has not been canceled, the control device 70 makes the above-mentioned determination again in step S400. That is, if it is determined that the increase signal has not been canceled, the increase mode is continued.

Next, in step S500, the control device 70 switches the battery unit 12 from the increase mode to the normal mode.

Specifically, the control device 70 deactivates the take-out pump 224 when the take-out pump 224 shown in FIG. 4 is in operation. Further, the control device 70 reduces the momentum of the cooling unit 42 shown in FIG. 1 and returns it to the momentum of the normal mode. Further, the control device 70 reduces the rotation speed of the heat recovery pump 40 shown in FIG. 1 and returns it to the rotation speed of the normal mode. Further, the control device 70 increases the rotation speed of the air blower 86 shown in FIG. 1 and returns it to the rotation speed of the normal mode.

When the control device 70 switches the battery unit 12 from the increase mode to the normal mode in step S500, the process proceeds to step S200, and the above-described steps are repeated.

(Summary)
As described above, when the control device 70 receives the increase signal for increasing the amount of condensed water produced, the control device 70 switches the battery unit 12 from the normal mode to the increase mode. As a result, the condensed water generated in the exhaust heat exchanger 31 is increased and collected in the reformed water tank 24 as reformed water W1. In this way, the amount of condensed water produced can be increased by the user's instruction to increase the amount of condensed water produced.

Further, in the fuel cell system 10, the take-out mechanism 220 takes out the increased reformed water W1 stored in the reformed water tank 24 from the reformed water tank 24, and the reformed water W1 is supplied from the housing 16 to the outside. Will be done. As a result, the user can use the water supplied to the outside as miscellaneous water.

Further, when the control device 70 receives an increase signal for increasing the amount of condensed water produced, the control device 70 increases the momentum of the cooling unit 42, increases the rotation speed of the heat recovery pump 40, and increases the rotation speed of the air blower 86. All of the reduction of the number of revolutions was performed. Therefore, the amount of condensed water produced can be increased as compared with the case where any one of them is executed.

Further, when an increase instruction for increasing the amount of condensed water generated from the user is input to the input unit 210, the control device 70 receives an increase signal for increasing the amount of condensed water generated, and the control device 70 receives the increase signal for increasing the amount of condensed water generated. Switch from normal mode to increase mode. In this way, the amount of condensed water produced can be increased by inputting an increase instruction from the user to the input unit 210 to increase the amount of condensed water produced.

Further, when the amount of reformed water W1 stored in the reformed water tank 24 becomes less than the reference value K1, the control device 70 receives an increase signal for increasing the amount of condensed water produced. Then, the control device 70 switches the battery unit 12 from the normal mode to the increase mode. As a result, the condensed water can supply the reformed water W1 supplied to the battery module 18.

<Second Embodiment>
The fuel cell system 310 according to the second embodiment of the present invention will be described with reference to FIG. The fuel cell system 310 of the second embodiment will be mainly described as being different from the fuel cell system of the first embodiment.

(Constitution)
As shown in FIG. 6, the fuel cell system 310 includes a reforming water tank 324, a water amount sensor 314, and a take-out mechanism 320.

-Modified water tank 324
The reforming water tank 324 has a box shape with an open upper part. The water amount sensor 314 is, for example, a capacitance type water amount sensor, and detects the amount of the reforming water W1 by detecting the water level of the reforming water W1.

-Removal mechanism 320-
As shown in FIG. 6, the take-out mechanism 320 includes a take-out pipe 322, a take-out port 328, a take-out valve 330, and a discharge pipe 344.

The take-out pipe 322 is L-shaped and has a horizontal portion 322a extending in the horizontal direction and a vertical portion 322b extending in the vertical direction. One end of the horizontal portion 322a is attached to the upper portion of the reference value K1 in the side plate 324a of the reforming water tank 324. Specifically, one end of the horizontal portion 322a is attached to the side plate 324a of the reforming water tank 324 so that the reforming water W1 exceeding the reference value K1 flows into the horizontal portion 322a. Further, the vertical portion 322b extends downward from the other end of the horizontal portion 322a, and the lower end of the vertical portion 322b reaches the bottom plate 16a of the housing 16.

The take-out port 328 is attached to the lower end of the vertical portion 322b of the take-out pipe 322, and the lower end of the vertical portion 322b of the take-out pipe 322 is attached to the bottom plate 16a of the housing 16. The take-out valve 330 is provided in the vertical portion 322b of the take-out pipe 322, and opens and closes the flow path formed in the take-out pipe 322.

The discharge pipe 344 has an L-shape and has a horizontal portion 344a extending in the horizontal direction and a vertical portion 344b extending in the vertical direction. One end of the horizontal portion 344a is attached to the upper end portion of the side plate 324a of the reforming water tank 324. Specifically, one end of the horizontal portion 344a is attached to the side plate 324a of the reforming water tank 324 so that the reforming water W1 that is about to overflow from the reforming water tank 324 flows into the horizontal portion 344a.

Further, the vertical portion 344b extends downward from the other end of the horizontal portion 344a, and the lower end of the vertical portion 344b reaches the bottom plate 16a of the housing 16.

In this configuration, when the battery unit 12 is operated in the increase mode and the reforming water W1 stored in the reforming water tank 324 exceeds the reference value K1, the reforming water W1 exceeding the reference value K1 is taken out from the piping. It flows into 322. Then, when the user opens the take-out valve 330, the reforming water W1 flows through the take-out port 328 and is supplied from the housing 16 to the outside. Then, the water supplied to the outside is used by the user.

Further, when the reforming water W1 stored in the reforming water tank 324 increases and tries to overflow from the reforming water tank 324, the reforming water W1 to overflow flows into the discharge pipe 344. Then, the reforming water W1 that has flowed into the discharge pipe 344 is discharged from the housing 16.

In this way, in the fuel cell system 310, the reforming water W1 that is about to overflow from the reforming water tank 324 can be discharged from the housing 16. Other actions are the same as in the first embodiment.

<Third Embodiment>
The fuel cell system 410 according to the third embodiment of the present invention will be described with reference to FIG. The fuel cell system 410 of the third embodiment will be mainly described as being different from the fuel cell system of the first embodiment.

(Constitution)
As shown in FIG. 7, the fuel cell system 410 includes a reforming water tank 24, a water amount sensor 214, and a take-out mechanism 420.

− Extraction mechanism 420−
As shown in FIG. 7, the take-out mechanism 420 includes a relay pipe 422, a water storage tank 428, a take-out pipe 430, a take-out valve 434, and a discharge pipe 436.

The relay pipe 422 has a crank shape, and has a horizontal portion 422a extending in the horizontal direction, a horizontal portion 422b, and a vertical portion 422c extending in the vertical direction. One end of the horizontal portion 422a is attached to the upper portion of the reference value K1 in the side plate 24a of the reforming water tank 24. Specifically, one end of the horizontal portion 422a is attached to the side plate 24a of the reforming water tank 24 so that the reforming water W1 exceeding the reference value K1 flows into the horizontal portion 422a. Further, the vertical portion 422c extends downward from the other end of the horizontal portion 422a. Further, the horizontal portion 422b extends in the horizontal direction from the lower end of the vertical portion 422c, penetrates the side plate 16b of the housing 16, and the tip of the horizontal portion 422b projects to the outside of the housing 16.

The water storage tank 428 has a rectangular parallelepiped shape extending in the vertical direction, and is arranged on the side of the housing 16 outside the housing 16. The bottom plate 428a of the water storage tank 428 is arranged below the lower end of the reforming water tank 24 in the vertical direction. Further, the top plate 428b of the water storage tank 428 is arranged at the same position as the upper end of the reforming water tank 24 in the vertical direction. Further, the tip of the horizontal portion 422b of the relay pipe 422 is attached to the side plate 428c of the water storage tank 428.

The take-out pipe 430 is attached to the bottom plate 428a of the water storage tank 428, and extends downward from the bottom plate 428a. The take-out valve 434 is provided in the take-out pipe 430 so as to open and close the flow path formed in the take-out pipe 430.

The discharge pipe 436 is L-shaped and has a horizontal portion 436a extending in the horizontal direction and a vertical portion 436b extending in the vertical direction. One end of the horizontal portion 436a is attached to the upper end portion of the side plate 428d of the water storage tank 428 arranged on the opposite side to the side plate 428c of the water storage tank 428. Further, the vertical portion 436b extends downward from the other end of the horizontal portion 436a.

In this configuration, when the battery unit 12 is operated in the increase mode and the reforming water W1 stored in the reforming water tank 24 exceeds the reference value K1, the reforming water W1 exceeding the reference value K1 relays. It flows into the pipe 422. Then, the reformed water W1 that has flowed into the relay pipe 422 flows out to the water storage tank 428 arranged outside the housing 16 and is stored in the water storage tank 428. Further, when the user opens the take-out valve 434, the reformed water W1 stored in the water storage tank 428 flows through the take-out pipe 430 and is supplied to the outside of the water storage tank 428.

Further, when the reformed water W1 stored in the water storage tank 428 increases and the reformed water W1 reaches one end of the horizontal portion 436a of the discharge pipe 436 attached to the water storage tank 428, it reaches one end of the horizontal portion 436a. The reformed water W1 flows into the discharge pipe 436. Then, the reforming water W1 that has flowed into the discharge pipe 436 flows through the discharge pipe 436 and is discharged from the water storage tank 428.

In this way, in the fuel cell system 410, the increased reformed water W1 can be temporarily stored in the water storage tank 428. Other actions are the same as in the first embodiment.

<Fourth Embodiment>
The fuel cell system 510 according to the fourth embodiment of the present invention will be described with reference to FIG. The fuel cell system 510 of the fourth embodiment will be mainly described as being different from the fuel cell system of the first embodiment.

As shown in FIGS. 8A and 8B, the ceiling wall 530a of the refrigerant tank 530 of the fuel cell system 510 is not formed with an opening, and the refrigerant tank 530 is a pressurized type filled with the refrigerant W2. It is said to be a tank. Further, the fuel cell system 510 is not provided with a water heat exchanger. The refrigerant tank 530 is an example of a refrigerant storage unit.

In order to exchange heat between the refrigerant W2 of the refrigerant tank 530 and the clean water supplied from the outside of the housing 16, the water pipe 552 whose end is connected to the lower end side of the refrigerant tank 30 and the refrigerant A discharge pipe 554 whose end is connected to the upper end side of the tank 530 is provided.

The water pipe 552 is a pipe for supplying clean water from the outside of the housing 16 to the 530, and the discharge pipe 554 is a pipe for discharging the clean water warmed by the refrigerant tank 530 to the outside of the housing 16.

Further, a blocking member 556 that blocks the flow of clean water is arranged in the middle of the water pipe 552, and a blocking member 558 that blocks the flow of clean water is arranged in the middle of the discharge pipe 554. Further, in the water pipe 552, a connecting pipe connecting the portion on the upstream side of the water flow direction with respect to the blocking member 556 and the portion of the drainage pipe 554 on the downstream side of the blocking member 558 in the water flow direction. 560 is provided. The drainage pipe 554 is an example of the first flow path member, and the blocking member 558 is an example of the first blocking member. The water pipe 552 is an example of a second flow path member, and the blocking member 556 is an example of a second blocking member.

Then, in the normal mode, the control device 70 controls the blocking members 556 and 558 to allow clean water to flow into the refrigerant tank 530 as shown in FIG. 8 (A). On the other hand, when the normal mode is switched to the increase mode, the control device 70 controls the blocking members 556 and 558 to block the flow of clean water into the refrigerant tank 530 as shown in FIG. 8 (B). Allows clean water to flow into the connecting pipe 560.

In this way, when the mode is switched from the normal mode to the increase mode, the user does not operate the blocking members 556 and 558 to block the flow of clean water to the refrigerant tank 530, so that the refrigerant can be used even when the water is cut off. The pressure holding state of the tank 530 can be maintained.

Further, the power generation of the battery module 18 can be continued by maintaining the holding pressure state of the refrigerant tank 530.

Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments can be taken within the scope of the present invention. That is clear to those skilled in the art. For example, in the above embodiment, the air blower 86 is used to supply air to the battery module 18, but other control members may be used as long as the amount of air supplied to the battery module 18 can be controlled.

Further, in the above embodiment, the combustion exhaust gas, which is an example of the exhaust gas discharged from the fuel cell, is cooled by the refrigerant W2 to generate condensed water. For example, when water is generated at the air electrode 84, air is generated. As an example of the exhaust gas discharged from the pole 84, the cathode off gas may be cooled by the refrigerant W2 to generate condensed water, and when water is generated at the fuel pole 84, the exhaust gas is discharged from the fuel pole 78. As an example of the exhaust gas, the anode off gas may be cooled by the refrigerant W2 to generate condensed water.

Further, in the above embodiment, when the battery unit 12 is switched from the normal mode to the increase mode, the momentum of the cooling unit 42 is increased, the rotation speed of the heat recovery pump 40 is increased, and the air blower 86 is operated in step S300. I've done everything to reduce the number of revolutions, but at least one should be done. However, in this case, the effect of doing everything does not occur.

Further, in the first embodiment, the reforming water W1 stored in the reforming water tank 24 is taken out by operating the take-out pump 224, but by using gravity without using the take-out pump. , A certain amount or more of the reforming water W1 may be taken out from the reforming water tank.

Further, in the above embodiment, the fuel cell system 10 is divided into two units, but it may be divided into three or more units.

Further, although not particularly described in the above embodiment, for example, a water pressure gauge is provided in the pipe 122 through which clean water flows, and when the water pressure detected by the water pressure gauge becomes "0", the control device 70 causes the condensed water. You may receive an increase signal that increases the amount of production. As a result, when the water supply is cut off, the battery unit 12 can be switched from the normal mode to the increase mode.

10 Fuel cell system 18 Battery module (example of fuel cell)
24 Remodeling water tank (an example of reformed water storage unit)
31 Exhaust heat exchanger (an example of exhaust heat exchanger)
40 Heat recovery pump (example of circulation part)
42 Cooling unit 70 Control device 86 Air blower (Example of air control unit)
210 Input unit 214 Water volume sensor 310 Fuel cell system 314 Water volume sensor 324 Remodeling water tank (an example of reforming water storage unit)
410 Fuel cell system 510 Fuel cell system 530 Refrigerant tank (an example of refrigerant storage)
552 water pipe (second flow path member)
554 Drainage pipe (first flow path member)
556 Blocking member (second blocking member)
558 blocking member (first blocking member)

Claims (7)

Fuel, air supplied using the air control unit, and a fuel cell to which reformed water for reforming the fuel is supplied to generate electricity,
An exhaust heat exchange unit that cools the exhaust gas of the fuel cell with a refrigerant to generate condensed water,
A cooling unit that cools the refrigerant and
A control device that increases the amount of heat exchange between the exhaust gas and the refrigerant by at least an increase instruction for increasing the amount of condensed water produced by the user.
Fuel cell system with. It has a reformed water storage unit that stores the condensed water as the reformed water.
It has a water amount sensor that detects the amount of reformed water stored in the reformed water storage unit.
The fuel cell according to claim 1, wherein when the amount of reformed water detected by the water amount sensor becomes less than a predetermined reference value, the control device increases the amount of heat exchange between the exhaust gas and the refrigerant. system. The fuel cell system according to claim 1 or 2, further comprising an input unit capable of inputting an increase instruction for increasing the amount of condensed water produced from the user. It has a circulation unit that circulates the refrigerant so that the refrigerant passes through the exhaust heat exchange unit.
The control device controls the cooling unit to increase the cooling amount of the refrigerant, controls the circulation unit to increase the amount of the refrigerant passing through the exhaust heat exchange unit per unit time, and the air. Any one of claims 1 to 3 that controls the control unit to reduce the amount of air supplied to the fuel cell, and executes at least one of them to increase the amount of heat exchange between the exhaust gas and the refrigerant. The fuel cell system described in the section. The control device controls the cooling unit to increase the cooling amount of the refrigerant, controls the circulation unit to increase the amount of the refrigerant passing through the exhaust heat exchange unit per unit time, and the air. The fuel cell system according to claim 4, wherein the control unit is controlled to reduce the amount of air supplied to the fuel cell, all of which are performed to increase the amount of heat exchange between the exhaust gas and the refrigerant. A pressurized refrigerant storage unit that circulates the refrigerant between the exhaust heat exchange unit and stores the refrigerant, and
The first flow path member through which the clean water warmed in the refrigerant storage section flows, and
A second flow path member through which clean water supplied to the refrigerant storage unit flows, and
A first blocking member that blocks the clean water warmed in the refrigerant storage section from flowing through the first flow path member,
A second blocking member that blocks the clean water supplied to the refrigerant storage unit from flowing through the second flow path member,
The fuel cell system according to any one of claims 1 to 5. At least in response to an increase instruction by the user to increase the amount of condensed water produced, the control device controls the first blocking member and blocks the clean water warmed by the refrigerant storage unit from flowing through the first flow path member. The fuel cell system according to claim 6, wherein the second blocking member is controlled to block the clean water supplied to the refrigerant storage unit from flowing through the second flow path member.