JP2007048595A - Fuel cell cogeneration system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cogeneration system capable of supplying hot water produced by utilizing exhaust heat from a fuel cell to a plurality of heat loads, and reducing consuming energy for heating the hot water to temperature required for the heat load, in spite of simple constitution. <P>SOLUTION: The fuel cell cogeneration system 10 is equipped with a hot water storage tank 52, first to third hot water supply pipes 58a, 58b, 58c connected to the hot water storage tank 52, and supplying stored hot water to first to third heat loads 56a, 56b, 56c, and first to third electric heaters 66a, 66b, 66c arranged in the vicinities of the first to third hot water supply pipes 58a, 58b. 58c, and operation of the first to third electric heaters is controlled so that temperatures T1, T2, T3 of the hot water in the first to third hot water supply pipes 58a, 58b, 58c become temperatures required for the heat loads being supplied. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel cell cogeneration system.

  Conventionally, there has been a fuel cell cogeneration system that generates hot water using exhaust heat of a fuel cell, stores the generated hot water in a hot water storage tank, and then supplies it to a thermal load (for example, hot water supply equipment). Various proposals have been made (see, for example, Patent Document 1). These fuel cell cogeneration systems generate hot water at the temperature required by the heat load even when the amount of power generated by the fuel cell is relatively small or when the fuel cell is not operating. An electric heater is attached.

  By the way, there are generally a plurality of heat loads to which hot water is supplied, for example, a hot water supply facility for bathing or a hot water supply facility for floor heating. Therefore, the temperature of the hot water required by the heat load differs depending on the type of the heat load, and the electric heater heats the hot water in the hot water tank according to the highest temperature required for each heat load. Was. As a result, there arises a disadvantage that the electric power (energy) consumed by the electric heater increases.

Thus, for example, in the technique described in Patent Document 2, hot water is stored in two hot water tanks, that is, a first hot water tank that stores hot hot water and a second hot water that stores low temperature hot water. A hot water storage tank is provided, and hot water is supplied from the first hot water tank for a heat load that requires high-temperature hot water, and hot water is supplied from a second hot water tank to a heat load that requires low-temperature hot water. .
JP 2001-68125 A (paragraph 0036, FIG. 1, etc.) JP 2002-75390 A (paragraph 0019, FIG. 1, etc.)

  However, since the technique disclosed in Patent Document 2 is configured to include two hot water storage tanks, pipes (hot water supply pipes) for connecting the two hot water storage tanks to the fuel cell or the thermal load are required. The problem that becomes complicated occurs.

  Therefore, the object of the present invention is to solve the above-described problems and to supply hot water generated by utilizing the exhaust heat of the fuel cell to a plurality of heat loads while having a simple configuration, An object of the present invention is to provide a fuel cell cogeneration system capable of reducing energy consumption when warm water is heated to a temperature required by the above.

  In order to solve the above-described object, the present invention includes a fuel cell that generates power by being supplied with air and fuel, and a hot water supply unit that generates hot water using exhaust heat of the fuel cell. In the fuel cell cogeneration system, the hot water storage tank in which the hot water is stored, a plurality of hot water supply pipes connected to the hot water storage tank and respectively supplying the stored hot water to a plurality of thermal loads, A plurality of heating means respectively disposed in the vicinity of the hot water supply pipes and the plurality of heating means so that the temperature of the hot water in the plurality of hot water supply pipes is a temperature required by the heat load to be supplied. And a control means for controlling the operation.

  According to a second aspect of the present invention, the heating means is constituted by an electric heater.

  In the fuel cell cogeneration system according to claim 1, a hot water tank that stores hot water generated by using the exhaust heat of the fuel cell, and a hot water tank that is connected to the hot water tank and stores the stored hot water are a plurality of A plurality of hot water supply pipes respectively supplied to the heat load and a plurality of heating means respectively disposed in the vicinity of the plurality of hot water supply pipes, the temperature of the hot water in the plurality of hot water supply pipes being the heat load to be supplied The operation of the plurality of heating means is controlled so that the required temperature is obtained, that is, the hot water in the plurality of hot water pipes is required by a thermal load by the corresponding heating means provided in the vicinity of each hot water pipe. Since it heated so that it might become temperature, it was a simple structure, but the hot water produced | generated using the exhaust heat of a fuel cell can be supplied to several heat load. Further, the heating means only needs to heat the hot water in the hot water supply pipe until the temperature required by the corresponding heat load is reached. That is, as in the prior art, the hot water in the hot water storage tank is heated within the temperature required by each heat load. Therefore, the energy consumed when the temperature of the hot water is raised can be reduced. Furthermore, since the heating means is arranged in the vicinity of the plurality of hot water supply pipes, the temperature of the hot water in the plurality of hot water supply pipes can be individually adjusted, so that the temperature of the hot water can be accurately adjusted to the temperature required by the heat load. The temperature can be increased.

  In the fuel cell cogeneration system according to claim 2, since the heating means is configured to be an electric heater, in addition to the above-described effects, hot water in the hot water supply pipe is supplied with a simpler configuration. The temperature can be raised to the temperature required by the power load.

  The best mode of the fuel cell cogeneration system according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram showing the configuration of a fuel cell cogeneration system according to a first embodiment of the present invention.

  In FIG. 1, reference numeral 10 denotes a fuel cell cogeneration system. The fuel cell cogeneration system 10 is a stationary system installed at home or the like. The fuel cell cogeneration system 10 is a fuel cell (stack) 12 that is supplied with air (cathode gas) and fuel (anode gas) to generate electric power, A hot water supply unit 14 that generates hot water using exhaust heat.

  The fuel cell 12 includes an electrolyte membrane (solid polymer membrane), a cathode electrode (air electrode) and an anode electrode (fuel electrode) sandwiching the electrolyte membrane, and a separator (none of which is shown) disposed outside each electrode. It is a known solid polymer fuel cell formed by stacking a plurality of unit cells composed of

  An air blower 16 that sucks air is connected to the cathode electrode of the fuel cell 12 via a cathode gas pipe 18. The air sucked by the air blower 16 is supplied to the cathode electrode of the fuel cell 12 via the cathode gas pipe 18 as cathode gas (reaction air). Further, a cathode offgas pipe 20 that discharges cathode gas discharged from the fuel cell 12 (hereinafter referred to as “cathode offgas”) to the atmosphere is connected to the cathode electrode of the fuel cell 12.

  The anode electrode of the fuel cell 12 includes an anode gas pipe 24 through which fuel to be supplied to the anode electrode flows, and a cathode that recirculates the anode gas discharged from the fuel cell 12 (hereinafter referred to as “anode offgas”) to the anode gas pipe 24. An off-gas pipe 26 is connected. The anode gas pipe 24 is connected to a fuel supply source (not shown) such as city gas upstream of the anode gas flow.

  The cathode gas pipe 18 is connected to a humidifier for humidifying the cathode gas, and the anode gas pipe 24 is connected to a desulfurizer, a reformer, a carbon monoxide converter, and the like. Since they have no direct relationship with the subject matter of the present application, the illustration and description thereof are omitted.

  The fuel cell 12 includes an output terminal 30 that outputs electric power generated by the fuel cell 12, and an inverter 32 that converts electric power (DC current) generated by the fuel cell 12 into an AC current having a predetermined frequency. Is connected. The inverter 32 is connected to an electronic control unit (Electronic Control Unit; hereinafter referred to as “ECU”) 34 formed of a microcomputer and an electrical load (for example, AC electrical equipment such as a lighting fixture) 36. The ECU 34 is connected to a power source (for example, a commercial power source), and is supplied with an alternating current when the amount of power generated by the fuel cell 12 is relatively small or when the fuel cell 12 is not operating.

  Connected to the fuel cell 12 is a first cooling system 40 a that circulates cooling water to cool the fuel cell 12. The first cooling system 40a includes a first cooling water pipe 42a through which the cooling water flows, and a first cooling water pump that pumps the cooling water to the fuel cell 12 in the middle of the first cooling water pipe 42a. 44a and a first heat exchanger 46a are arranged. The cooling water in the first cooling water pipe 42a is pumped to the first cooling water pump 44a, so that it flows through the fuel cell 12 and the first heat exchanger 46a, and again flows to the first cooling water pump 44a. Can be circulated.

  The aforementioned hot water supply unit 14 is connected to the first heat exchanger 46a. The hot water supply unit 14 cools the cooling water of the first cooling system 42a, which has been heated by cooling the fuel cell 12, by circulating the cooling water through the first heat exchanger 46a. 40b is connected to the second cooling system 40b via the second heat exchanger 46b, and hot water is supplied from the cooling water of the second cooling system 40b that has been heated by the first heat exchanger 46a. A hot water supply system 50 that generates and supplies the hot water to a heat load (described later).

  The second cooling system 40b includes a second cooling water pipe 42b through which cooling water flows. The second cooling water pipe 42b includes the first and second heat exchangers 46a and 46b, the third heat exchanger 46c connected to the heat load, and the cooling water from the first to the third heat. A second cooling water pump 44b that is pumped to the exchangers 46a, 46b, and 46c is disposed. The cooling water in the second cooling water pipe 42b flows through the first heat exchanger 46a, the second heat exchanger 46b, and the third heat exchanger 46c by being pumped to the second cooling water pump 44b. Then, it flows again to the second cooling water pump 44b and is circulated.

  The hot water supply system 50 is connected to the hot water storage tank 52 in which hot water is stored, the first and second hot water pipes 54a and 54b connecting the hot water storage tank 52 and the second heat exchanger 46b, and the hot water storage tank 52. And a hot water supply pipe 58 that supplies the stored hot water to the heat load 56.

  A warm water pump 60 that pumps warm water is disposed in the first warm water pipe 54a. The hot water is circulated in the order of the first hot water pipe 54a, the second heat exchanger 46b, the second hot water pipe 54b, the hot water tank 52, and the first hot water pipe 54a by being pumped to the hot water pump 60. It is done. Further, a water supply pipe 64 is connected to the first hot water pipe 54a, and when the amount of hot water stored in the hot water storage tank 52 decreases, water is supplied (supplemented) to the first hot water pipe 54a.

  The hot water supply pipe 58 includes a first hot water supply pipe 58a and a first hot water supply pipe 58a for supplying the hot water in the hot water storage tank 52 to a heat load (hereinafter referred to as “first heat load”) 56a such as a hot water tap of a kitchen, for example. The hot water is branched from a first hot water supply pipe 58a and a second hot water supply pipe 58b that supplies hot water to a hot water supply facility (hereinafter referred to as a “second heat load”) 56b for bathing, for example. For example, a third hot water supply pipe 58c that supplies hot water supply equipment for floor heating (hereinafter referred to as "third heat load") 56c.

  Near the first hot water supply pipe 58a, a first electric heater (heating means) 66a for heating the hot water in the first hot water supply pipe 58a is disposed. The first hot water supply pipe 58a is arranged between the first electric heater 66a and the first thermal load 56a. The first hot water temperature sensor 70a outputs a signal corresponding to the temperature T1 of the hot water in the first hot water supply pipe 58a.

  In the vicinity of the second hot water supply pipe 58b, a second electric heater (heating means) 66b for heating the hot water in the second hot water supply pipe 58b is disposed. Further, a second hot water temperature sensor 70b is disposed on the downstream side of the second electric heater 66b in the hot water flow in the second hot water supply pipe 58b. The second hot water temperature sensor 70b outputs a signal corresponding to the temperature T2 of the hot water in the second hot water supply pipe 58b.

  A fourth heat exchanger 46d is disposed downstream of the second hot water temperature sensor 70b in the second hot water supply pipe 58b. The fourth heat exchanger 46d is connected to the hot water pipe 56b1 of the second heat load 56b, and heat is transferred between the hot water in the second hot water supply pipe 58b and the hot water in the hot water pipe 56b1. The hot water pipe 56b1 is provided with a second hot load hot water pump 56b2 that pumps the hot water to the fourth heat exchanger 46d and circulates the hot water pipe 56b1.

  Near the third hot water supply pipe 58c, a third electric heater (heating means) 66c for heating the hot water in the third hot water supply pipe 58c is disposed. A signal corresponding to the temperature T3 of the hot water in the third hot water supply pipe 58c is output in the middle of the third hot water supply pipe 58c, specifically, downstream of the third electric heater 66c in the flow of hot water. 3 hot water temperature sensors 70c are arranged.

  A fifth heat exchanger 46e is disposed on the downstream side of the third hot water temperature sensor 70c in the third hot water supply pipe 58c. A hot water pipe 56c1 of the third heat load 56c is connected to the fifth heat exchanger 46e. That is, the hot water in the third hot water supply pipe 58c and the hot water in the hot water pipe 56c1 are exchanged of heat in the fifth heat exchanger 46e. The hot water pipe 56c1 is provided with a third heat load hot water pump 56c2 for pumping hot water to the fifth heat exchanger 46e and the third heat exchanger 46c to circulate the hot water pipe 56c1.

  The first to third electric heaters 66a, 66b, 66c are made of a heating wire such as a nichrome wire, an insulating material and a protective tube for covering the heating wire, and a current is supplied to the heating wire from a power source (not shown). It is an electric heater that sometimes generates heat.

  As described above, the plurality of hot water supply pipes, specifically, the first to third hot water supply pipes 58a, 58b, 58c) are connected to the hot water storage tank 52, and the stored hot water is supplied with a plurality of thermal loads (first 1 to third heat loads 56a, 56b, 56c), and a plurality of electric heaters (first to third electric heaters 66a, 66a, 66b, 66c) are arranged.

  The second and third hot water supply pipes 58b and 58c join at the end portion on the most downstream side, and are connected to the fourth hot water supply pipe 58d. The fourth hot water supply pipe 58d is connected to the first hot water pipe 54a.

  As shown in the figure, the ECU 34 connects the air blower 16, the first and second cooling water pumps 44 a and 44 b, the hot water pump 60, the first to third electric heaters 66 a, 66 b and 66 c, and the signal line 72. Connected and control their operation. Further, the ECU 34 is connected to the first to third hot water temperature sensors 70a, 70b, 70c via a signal line 74, and signals output from these sensors are input. The second heat load 56b and the second heat load hot water pump 56b2, and the third heat load 56c and the third heat load hot water pump 56c2 are connected via signal lines 76 and 78, respectively. When the second and third heat loads 56b and 56c are used, the heat load hot water pumps 56b2 and 56c2 are driven.

  Next, the operation of the fuel cell cogeneration system 10 will be outlined.

  When an instruction to start the fuel cell cogeneration system 10 is given (more specifically, when a start switch (not shown) is turned on by an operator), fuel is supplied from the fuel supply source to the anode gas pipe 24. The fuel is reformed into a reformed gas containing hydrogen by a reformer (not shown) disposed in the anode gas pipe 24 and then supplied to the anode electrode of the fuel cell 12 as an anode gas. When the anode gas is supplied to the fuel cell 12, the air blower 16 is then driven, and the power generation of the fuel cell 12 is started.

More specifically, the cathode gas (air) sucked by the air blower 16 is supplied to the cathode electrode of the fuel cell 12 via the cathode gas pipe 18. The cathode gas supplied to the cathode electrode of the fuel cell 12 causes an electrochemical reaction with the anode gas supplied to the anode electrode. The electrode reaction occurring at the cathode and anode is specifically as follows.
Anode electrode: H ₂ → 2H ⁺ + 2e ⁻
Cathode electrode: 1 / 2O ₂ + 2H ⁺ + 2e ⁻ → H ₂ O
Therefore, the overall reaction is:
Overall: H ₂ + 1 / 2O ₂ → H ₂ O

  The electric power generated by the fuel cell 12 by the above reaction is taken out from the output terminal 30 and converted into an alternating current having a predetermined frequency by the inverter 32, and then a part of the electric power is supplied to the auxiliary equipment such as the ECU 34 and the air blower 16. And the remainder is supplied to the electrical load 36.

  The cathode offgas discharged from the fuel cell 12 is discharged into the atmosphere via the cathode offgas pipe 20. Further, the anode off gas (unreacted gas) discharged from the fuel cell 12 is refluxed from the anode off gas pipe 26 to the anode gas pipe 24 and supplied to the fuel cell 12 again.

  The cooling water in the first cooling water pipe 42 a is pumped to the fuel cell 12 by the first cooling water pump 44 a and passes through the inside of the fuel cell 12 to cool the fuel cell 12. A part of the cooling water raised in temperature by cooling the fuel cell 12 is supplied to the first heat exchanger 46a, where heat is exchanged with the cooling water in the second cooling water pipe 42b. The remaining portion passes through a radiator (not shown) and is radiated to the atmosphere.

  The cooling water in the second cooling water pipe 42b that has been raised in temperature by the first heat exchanger 46a is supplied to the second heat exchanger 46b by the second cooling water pump 44b. Therefore, heat is exchanged between the cooling water in the second cooling water pipe 42b and the hot water in the hot water supply system 50. In other words, the water in the hot water supply system 50 is heated to generate hot water. That is, the exhaust heat of the fuel cell 12 is supplied to the second heat exchanger 46b through the first and second cooling systems 40a and 40b, and hot water is generated there.

  The cooling water in the second cooling water pipe 42b passes through the second heat exchanger 46b and is then supplied to the third heat exchanger 46c. The cooling water in the second cooling water pipe 42b is exchanged with the hot water in the hot water pipe 56c1 in the third heat exchanger 46c to increase the temperature of the hot water in the hot water pipe 56c1. That is, the exhaust heat of the fuel cell 12 is supplied to the third heat exchanger 46c via the first and second cooling systems 40a and 40b, and the hot water in the hot water pipe 56c1 is raised there.

  The hot water generated in the second heat exchanger 46b is supplied to the hot water tank 52 via the second hot water pipe 54b by the hot water pump 60 and stored. Further, since the stored hot water is circulated by the hot water pump 60, the hot water is supplied again to the second heat exchanger 46b via the first hot water pipe 54a to be heated.

  When the first heat load 56a is used, the hot water in the hot water storage tank 52 is supplied to the first heat load 56a through the first hot water supply pipe 58a. The hot water in the hot water tank 52 is supplied to the fourth heat exchanger 46d by the hot water pump 60 via the second hot water supply pipe 58b. In the fourth heat exchanger 46d, heat is transferred between the hot water in the second hot water supply pipe 58b and the hot water in the hot water pipe 56b1, and the hot water in the hot water pipe 56b1 is heated.

  The hot water in the hot water storage tank 52 is further supplied to the fifth heat exchanger 46e by the hot water pump 60 via the third hot water supply pipe 58c. Therefore, heat is exchanged between the hot water in the third hot water supply pipe 58c and the hot water pipe 56c1, and the temperature of the hot water in the hot water pipe 56c1 is increased. Therefore, the temperature of the hot water in the hot water pipe 56c1 is raised by both the fifth heat exchanger 46e and the third heat exchanger 46c.

  The hot water in the second and third hot water supply pipes 58b and 58c that has passed through the fourth and fifth heat exchangers 46d and 46e flows into the fourth hot water supply pipe 58c and is returned to the hot water tank 52 again by the hot water pump 60. Is done.

  As described above, the hot water stored in the hot water tank 52 is supplied to the first to third thermal loads 56a, 56b, and 56c. However, when the amount of power generated by the fuel cell 12 is relatively small (that is, when the amount of heat generated by the fuel cell 12 is relatively small) or when the fuel cell 12 is not in operation, the hot water stored in the hot water storage tank 52 is There is a risk that the temperature will drop and hot water at the temperature required by each of the thermal loads 56a, 56b, 56c cannot be supplied. Therefore, it is conceivable to provide an electric heater in the hot water tank, but with such a configuration, when the temperature of the hot water required by the heat load differs, the temperature of the hot water in the hot water tank is the temperature required by each heat load. It heats so that it may become the highest temperature among these, and the electric power consumed with an electric heater increases. Therefore, in the fuel cell cogeneration system 10 according to the present invention, the first to third electric heaters 66a, 66b, and 66c are provided in the vicinity of the first to third hot water supply pipes 58a, 58b, and 58c, respectively. I did it.

  FIG. 2 is a flowchart showing processing related to control of operations of the first to third electric heaters 66a, 66b, and 66c, which is executed by the ECU.

  First, in S10, the output of the first hot water temperature sensor 70a is read, and the temperature T1 of the hot water in the first hot water supply pipe 58a is detected. Next, the process proceeds to S12, in which the detected temperature T1 of the hot water in the first hot water supply pipe 58a is the first predetermined value, more precisely the temperature required by the first thermal load 56a (for example, about 36 [° C.]). It is judged whether or not it exceeds.

  When the result in S12 is affirmative, that is, when the hot water in the first hot water supply pipe 58a exceeds the temperature required by the first heat load 56a, the process proceeds to S14, and the first electric heater 66a is de-energized. The hot water in the first hot water supply pipe 58a is not heated. On the other hand, when the result in S12 is negative, the program proceeds to S16, in which the first electric heater 66a is energized to heat the hot water in the first hot water supply pipe 58a, so that the temperature T1 of the hot water becomes the first predetermined value. To.

  Next, the process proceeds to S18, the output of the second hot water temperature sensor 70b is read, the temperature T2 of the hot water in the second hot water supply pipe 58b is detected, the process proceeds to S20, and the temperature T2 of the hot water detected in S18 is the second temperature T2. More specifically, it is determined whether or not a temperature required by the second thermal load 56b (for example, about 40 [° C.]) is exceeded.

  When the result in S20 is affirmative, specifically, when the hot water in the second hot water supply pipe 58b exceeds the temperature required by the second heat load 56b, the process proceeds to S22 and the second electric heater 66b. Is not energized, and the hot water in the second hot water supply pipe 58b is not heated. When the result in S20 is negative, the program proceeds to S24, and the second electric heater 66b is energized. That is, the hot water in the second hot water supply pipe 58b is heated by the second electric heater 66b so that the temperature T2 of the hot water becomes the second predetermined value.

  Next, in S26, the output of the third temperature sensor 70c is read, and the temperature T3 of the hot water in the third hot water supply pipe 58c is detected. Next, the process proceeds to S28, where it is determined whether or not the detected temperature T3 of the hot water exceeds a third predetermined value, more precisely, a temperature required by the third heat load 56c (for example, about 65 [° C.]). .

  When the result in S28 is affirmative, the process proceeds to S30, the third electric heater 66c is de-energized, and the hot water in the third hot water supply pipe 58c is not heated. On the other hand, when the result in S28 is negative, in other words, when the hot water in the third hot water supply pipe 58c does not exceed the temperature required by the third heat load 56b, the process proceeds to S32, where the third electric heater The hot water in the third hot water supply pipe 58c is heated by energizing 66c so that the temperature T3 of the hot water becomes the above-mentioned third predetermined value.

  As described above, in the fuel cell cogeneration system 10 according to the first embodiment, the fuel cell 12 is supplied with air and fuel to generate power, and the hot water is generated using the exhaust heat of the fuel cell 12. The hot water supply unit 14, a hot water storage tank 52 in which hot water is stored, and the hot water storage tank 52 are connected to supply the stored hot water to a plurality of heat loads (first to third heat loads 56a, 56b, 56c). A plurality of hot water pipes, specifically, a plurality of first to third hot water pipes 58a, 58b, 58c and a plurality of hot water pipes arranged in the vicinity of the first to third hot water pipes 58a, 58b, 58c, respectively. Heating means (that is, first to third electric heaters 66a, 66b, 66c) and temperatures T1, T2, T3 of hot water in the first to third hot water supply pipes 58a, 58b, 58c should be supplied. Required by heat load Control means (ECU 34) for controlling the operation of the first to third electric heaters 66a, 66b, 66c so as to become the degree (first to third predetermined value), that is, each hot water supply pipe 58a, 58b. , 58c is configured to heat the hot water in the first to third hot water supply pipes 58a, 58b, 58c to a temperature required by the heat load by corresponding electric heaters 66a, 66b, 66c. did.

  Thereby, although it is a simple structure, the warm water produced | generated using the exhaust heat of the fuel cell 12 can be supplied to several thermal load 56a, 56b, 56c from which the temperature of the required warm water differs. . Further, each of the electric heaters 66a, 66b, and 66c only needs to heat the hot water in the hot water supply pipes 58a, 58b, and 58c until the temperature required by the corresponding heat load is reached, that is, the electric heater provided in the hot water storage tank. As described above, since the hot water in the hot water tank is not heated to the highest temperature among the temperatures required by each heat load, the power consumption (energy) when raising the temperature of the hot water can be reduced. Furthermore, since the electric heaters 66a, 66b, 66c are arranged in the vicinity of the first to third hot water supply pipes 58a, 58b, 58c, respectively, the temperature of the hot water in each of the hot water supply pipes 58a, 58b, 58c is individually set. Therefore, the temperature of the hot water can be accurately raised to the temperature required by the heat load.

  In addition, since the heating means disposed in the vicinity of each hot water supply pipe 58a, 58b, 58c is constituted by the electric heaters 66a, 66b, 66c, the hot water supply pipes 58a, 58b, 58c can be made even simpler. The hot water inside can be heated (heated up) to the temperature of the hot water required by the heat load to be supplied.

  In addition, in the above, although the temperature of the hot water requested | required by each thermal load 56a, 56b, 56c was shown concretely, those numerical values are illustrations and are not limited. Moreover, although it comprised so that three heat loads might be provided, two or four or more may be sufficient.

  Further, although the heating means is constituted by an electric heater, in addition to that, a heat exchanger such as the third heat exchanger 46c to which the exhaust heat of the fuel cell 12 is supplied is provided for each hot water supply pipe 58a, 58b, The hot water in each of the hot water supply pipes 58a, 58b, and 58c may be further heated in the vicinity of 58c.

  In addition, although the fuel cell 12 is a solid polymer type, the present invention is not limited thereto, and other types may be used.

  Moreover, although it comprised so that city gas might be used as a fuel, LP gas, kerosene, methanol, naphtha, biomass, gasoline, etc. may be sufficient.

It is the schematic which shows the structure of the fuel cell cogeneration system which concerns on 1st Example of this invention. FIG. 4 is a flowchart showing processing related to control of operations of first to third electric heaters, which is executed by an electronic control unit (ECU) shown in FIG. 1. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Fuel cell cogeneration system, 12 Fuel cell, 14 Hot water supply unit, 34 Electronic control unit (ECU. Control means), 52 Hot water storage tank, 56a 1st thermal load (thermal load), 56b 2nd thermal load (thermal load) ), 56c third heat load (heat load), 58a first hot water pipe (hot water pipe), 58b second hot water pipe (hot water pipe), 58c third hot water pipe (hot water pipe), 66a first Electric heater (heating means), 66b Second electric heater (heating means), 66c Third electric heater (heating means)

Claims (2)

  In a fuel cell cogeneration system comprising a fuel cell that is supplied with air and fuel to generate electricity, and a hot water supply unit that generates hot water using exhaust heat of the fuel cell, a hot water storage tank in which the hot water is stored; A plurality of hot water pipes connected to the hot water tank and supplying the stored hot water to a plurality of heat loads, respectively, a plurality of heating means respectively disposed in the vicinity of the plurality of hot water pipes; and And a control means for controlling the operation of the plurality of heating means so that the temperature of the hot water in the plurality of hot water supply pipes is a temperature required by the heat load to be supplied. Generation system. 2. The fuel cell cogeneration system according to claim 1, wherein the heating means is constituted by an electric heater.

Images