JP4911879B2 - Fuel cell exhaust heat utilization system capable of effectively utilizing exhaust heat of fuel cell, and building - Google Patents

Description

  The present invention relates to a fuel cell exhaust heat utilization system capable of effectively utilizing exhaust heat of a fuel cell, and a building. In particular, the present invention relates to a fuel cell exhaust heat utilization system that can further obtain electric power from the exhaust heat of the fuel cell, and a building.

  Conventionally, a fuel cell or the like has been considered as an auxiliary power source for a power system in a house. Since a fuel cell generates heat with power generation, a system that generates hot water from the generated heat and uses the generated hot water in a building is known (for example, see Non-Patent Document 1).

Written by Hiroshi Ishii, supervised by the Fuel Cell Development Information Center, "Book that understands fuel cells", 1st edition, Ohm Corporation, September 25, 2001

  However, when extra hot water is generated due to exhaust heat of the fuel cell, the extra hot water is discarded without being used in the building. As described above, there is a problem that the exhaust heat of the fuel cell is not necessarily utilized effectively.

  In order to solve such problems, the fuel cell exhaust heat utilization system according to the first aspect of the present invention supplies a fuel cell, a cold water tank that stores cold water supplied from a water pipe, and supplies cold water from the cold water tank. A cold water pipe, a heat generation amount generated by the fuel cell, and a temperature difference power generation device that generates power using a temperature difference between the cold water stored in the cold water tank are provided. Thereby, further electric power can be obtained from the exhaust heat of the fuel cell, and the exhaust heat of the fuel cell can be used effectively.

  The cold water tank may be connected to the cold water pipe at the top. Thereby, the water of the upper part of a cold water tank warmed by the temperature difference power generation device can be discharged | emitted from a cold water tank.

  The cold water tank may be connected to the water pipe at the bottom. Thereby, cooler water can be stored in the lower part of a cold water tank.

  The cold water tank may be open to both the cold water pipe and the water pipe. Thereby, since the water of cold water piping is pressurized with the pressure of a water pipe, the user of a building can obtain cold water only by twisting a faucet.

  The fuel cell further includes a hot water tank for storing hot water generated by the fuel cell and a hot water pipe for supplying hot water from the hot water tank to the home. Power generation may be performed using the temperature difference between Thereby, further electric power can be obtained using the hot water generated from the exhaust heat of the fuel cell.

  The upper part of the cold water tank may be connected to the lower part of the hot water tank. Thereby, the water heated by the power generation of the temperature difference power generation device can be released from the cold water to the hot water tank.

  The hot water tank may be open to the cold water tank. Thereby, since a warm water tank is pressurized with the pressure of a cold water tank, the user of a building can obtain warm water only by twisting a faucet.

  The hot water tank is provided integrally with the cold water tank on the cold water tank, and the cold water pipe may be connected to the cold water tank above the water pipe and below the hot water pipe. Thereby, when there is much quantity of warm water, warm water can be stored in a cold water tank, and when there is much quantity of cold water, cold water can be stored in a warm water tank.

  The building according to the second aspect of the present invention includes a fuel cell, a cold water tank that stores cold water supplied from a water pipe, a cold water pipe that supplies cold water from the cold water tank, an amount of heat generated by the fuel cell, and a cold water tank. And a temperature difference power generation device that generates power using a temperature difference from the stored cold water.

  The building in this embodiment further includes a hot water tank that stores hot water generated by the fuel cell, and a hot water pipe that supplies hot water from the hot water tank to the home, and the temperature difference power generation device includes hot water stored in the hot water tank, cold water You may generate electric power using the temperature difference with the cold water stored in the tank.

  The hot water tank is provided integrally with the cold water tank on the cold water tank, and the cold water pipe may be connected to the cold water tank above the water pipe and below the hot water pipe.

  The above summary of the invention does not enumerate all necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

  Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the claimed invention, and all the combinations of features described in the embodiments are not included in the invention. It is not always essential for development means.

  FIG. 1 shows a building 800 equipped with a fuel cell exhaust heat utilization system 100 according to an embodiment of the present invention. The fuel cell waste heat utilization system 100 includes a fuel cell 40, a cold water tank 42, a hot water tank 44, a temperature difference power generation device 46, a water pipe 48, a cold water pipe 50, a hot water pipe 52, a control unit 54, and two temperature sensors 56, 58. And a fuel cell cooling pump 60.

  The fuel cell 40 is, for example, a polymer electrolyte fuel cell, which generates electric power and generates heat. The fuel cell 40 of this example may be one that reforms city gas or propane gas supplied to the building 800 to generate hydrogen gas as fuel, and uses hydrogen gas supplied from the outside. It may be a fuel.

  The water pipe 48 is connected to a cold water tank 42, and the cold water tank 42 stores cold water supplied from the water pipe 48. In the present embodiment, the hot water tank 44 is integrally provided on the cold water tank 42, and in this case, the upper side of the cold water tank 42 is connected to the lower side of the hot water tank 44 by the connection pipe 51. Thereby, the hot water tank 44 is opened with respect to the cold water tank 42. The hot water tank 44 is supplied with water from the cold water tank 42 via the connection pipe 51. As another form, the cold water tank 42 and the hot water tank 44 may be physically separated and connected by a connection pipe 51.

  Here, the hot water tank 44 stores the hot water generated by the fuel cell 40. In this case, the fuel cell cooling pump 60 discharges heat generated in the fuel cell 40 to the hot water tank 44 by circulating a coolant such as water in each of the fuel cell 40 and the hot water tank 44. In this case, the exhaust heat of the fuel cell 40 is exhausted above the hot water tank 44. Thus, in this example, since the tap water is supplied from the lower side of the cold water tank 42 by the water pipe 48 and the hot water is generated above the hot water tank 44, the cold water is stored in the cold water tank 42. The tank 44 stores hot water that is warmer than the cold water stored in the cold water tank 42.

  The temperature difference power generation device 46 of this example performs power generation using the temperature difference between the hot water stored in the hot water tank 44 and the cold water stored in the cold water tank 42. The temperature difference power generation device 46 of this example includes two evaporators 62 and 64, a condenser 66, a working medium circulation pump 68, a working medium pipe 70, a turbine 72 and a generator 76. The working medium pipe 70 connects the condenser 66, the working medium circulation pump 68, the two evaporators 64 and 62, and the turbine 72 in series in this order. The condenser 66 includes a working medium containing alcohol, ammonia, or the like in advance. The working medium circulation pump 68 supplies the working medium to the condenser 66, the evaporators 64 and 62, and the turbine 72. Cycle in order.

  The condenser 66 of this example is disposed inside the cold water tank 42. Then, the working medium circulation pump 68 sends the liquefied working medium to the evaporator 64. The evaporator 64 is disposed inside the hot water tank 44. The evaporator 64 evaporates the liquefied working medium using the hot water stored in the hot water tank 44. Further, in this example, the evaporator 62 is arranged downstream of the fuel cell 40 and upstream of the hot water tank 44 along the direction of the refrigerant circulated by the fuel cell cooling pump 60. Here, the evaporator 62 evaporates the liquefied working medium using a refrigerant for exchanging the exhaust heat between the fuel cell 40 and the hot water tank 44, the temperature of which increases due to the exhaust heat from the fuel cell 40. Let

  The working medium pipe 70 supplies the working medium evaporated in the evaporator 62 and the evaporator 64 to the turbine 72. The turbine 72 is connected to a generator 76, and the generator 76 generates electric power. Here, the evaporated working medium is sent to the condenser 66 through the working medium pipe 70. Then, the condenser 66 condenses the evaporated working medium using the cold water stored in the cold water tank 42. As described above, the temperature difference power generation device 46 of this example can further obtain electric power by using the hot water generated from the exhaust heat of the fuel cell 40.

  Here, the condenser 66 raises the temperature of the cold water in the cold water tank when the evaporated working medium is condensed. In this case, the water heated by the temperature difference power generation device 46 is stored above the cold water tank. Here, the cold water tank 42 of the present invention is connected to the cold water pipe 50 at the upper side, and the cold water pipe 50 supplies cold water from the cold water tank 42 to the home. Thereby, the cold water piping 50 can discharge the warm cold water from the cold water tank 42. The cold water tank 42 is connected to the water pipe 48 at the lower side. Thereby, the cold water tank 42 can store cooler water in the lower part of the cold water tank 42. In this example, the cold water tank 42 is open to both the cold water pipe 50 and the water pipe 48. Thereby, since the water of the cold water piping 50 is pressurized by the pressure of the water pipe 48, the user of the building 800 can obtain cold water only by twisting the faucet.

  Further, the hot water pipe 52 is connected to the hot water tank 44. In this case, the cold water pipe 50 is connected to the cold water tank 42 above the water pipe 48 and below the hot water pipe 52. The hot water pipe 52 supplies hot water from the hot water tank 44 to the home. In this case, since the hot water tank 44 is open to the cold water tank 42, the hot water tank 44 is pressurized by the pressure of the cold water tank 42. Thereby, the user of the building 800 can obtain hot water only by twisting the faucet. Further, when the amount of hot water is large, the hot water can be stored in the cold water tank 42, and when the amount of cold water is large, the cold water can be stored in the hot water tank 44. In this example, since the upper part of the cold water tank 42 is connected to the lower part of the hot water tank 44, the water heated by the power generation of the temperature difference power generation device 46 can be released from the cold water tank 42 to the hot water tank 44.

  In this example, the working medium is a medium that condenses at a temperature higher than the temperature of the cold water in the cold water tank 42 and evaporates at a temperature lower than the temperature of the hot water in the hot water tank 44. For example, when a polymer electrolyte fuel cell is used as the fuel cell 40, the temperature of the hot water in the hot water tank 44 is about 60 ° C. to 80 ° C., and the temperature of the cold water in the cold water tank 42 is the temperature of tap water, for example, Since the temperature is about 5 ° C to 25 ° C, a medium having a boiling point between 25 ° C and 60 ° C may be used as the working medium.

  When power generation is performed using the temperature difference power generation device 46, the temperature of the hot water in the evaporator 64 is higher than the boiling point of the working medium, and the temperature of the cold water in the condenser 66 is equal to that of the working medium. The temperature must be lower than the boiling point. Therefore, the temperature sensor 56 of this example detects the temperature of the cold water stored in the cold water tank 42, and the temperature sensor 58 detects the temperature of the hot water stored in the hot water tank 44. The control unit 54 controls the operation of the fuel cell 40 and the temperature difference power generator 46 based on the temperature of the cold water stored in the cold water tank 42 and the temperature of the hot water stored in the hot water tank 44. In this example, the temperature difference is determined when the temperature of the hot water in the hot water tank 44 is higher than the boiling point of the working medium by a predetermined value or more and the temperature of the cold water in the cold water tank 42 is lower than the boiling point of the working medium by a predetermined value or more. Use it to generate electricity. Details of the control will be described with reference to FIG.

FIG. 2 is a state diagram showing an example of the operation of the fuel cell exhaust heat utilization system 100. Here, the current household power consumption P is greater than the maximum power value P ₂ that the fuel cell 40 can generate, and the temperature Ta of the hot water tank 44 is higher than the boiling point of the working medium by a predetermined temperature. a the temperature above T ₁ and the temperature Tb of the cold water tank 42, when it is low temperature T ₂ less by a predetermined temperature than the boiling point of the working medium, the control unit 54, the fuel cell 40 and the temperature difference Both of the generators 46 are operated. Here, the predetermined temperature may be 10 ° C., for example. Thereby, the building 800 of the present invention can obtain larger electric power than the case where only the fuel cell 40 is operated.

When the current household power consumption P is greater than the maximum power P ₁ that can be generated by the temperature difference power generation device 46 and equal to or less than P ₂ , the control unit 54 determines whether the temperature Ta of the hot water tank 44 and Regardless of the temperature Tb of the cold water tank 42, the fuel cell 40 generates power without generating power by the temperature difference power generation device 46. In addition, when the temperature Ta of the hot water tank 44 is lower than T ₁ or the temperature Tb of the cold water tank 42 is higher than T ₂ , the control unit 54 may The fuel cell 40 generates power without generating power by the temperature difference power generation device 46. In this case, for example, when the power consumption P of the home is greater than P _2, the water pipe 48, as a minute power shortage in the fuel cell 40, to supply the external commercial power to the home.

When the power consumption P is P ₁ or less, the temperature Ta of the hot water tank 44 is T ₁ or more, and the temperature Tb of the cold water tank 42 is T ₂ or less, the control unit 54 Power generation is performed only by the differential power generation device 46. Thereby, consumption of the raw fuel in the fuel cell 40 can be suppressed. When there is no demand for power, neither the fuel cell 40 nor the temperature difference power generation device 46 generates power.

In the present embodiment, when the fuel cell 40 are operated, the temperature of the evaporator 62 is higher than always T _1. Therefore, for example, when the power consumption P is larger than P _{2 and} the temperature Tb of the cold water tank 42 is lower than T ₂ , the evaporator 62 can be operated even if the temperature of the hot water in the hot water tank 44 is lower than T _1. Therefore, the control unit 54 can start the operation of the temperature difference power generation device 46. As described above, the fuel cell exhaust heat utilization system 100 according to the present invention can obtain more power from the exhaust heat of the fuel cell 40, and therefore can effectively utilize the exhaust heat of the fuel cell 40.

  In another example, the temperature difference power generation device 46 may further include a decompression unit that decompresses the working medium. In this case, the depressurizing means is provided between the evaporator 62 and the turbine 72, for example, and evaporates the working medium by depressurizing the working medium warmed by the hot water in the hot water tank 44. Here, for example, the evaporators 62 and 64 may pressurize and heat the working medium in a liquid state, and the decompression unit may decompress the working medium to a pressure lower than the pressurized pressure. Thereby, the working medium that has become steam or the working medium that has become a mixture of steam and liquid is supplied to the turbine 72, and the generator 76 can obtain electric power. The pressure reducing means may be a pressure reducing valve, for example.

  Further, the fuel cell exhaust heat utilization system 100 of this example performs power generation by operating the turbine 72 using a working medium. However, in other examples, power generation may be performed by using a thermoelectric element. . In this case, the temperature difference power generation device 46 has a thermoelectric element instead of the turbine 72, the generator 76, the two evaporators 62 and 64, the condenser 66, the working medium pipe 70, and the working medium circulation pump 68. Here, in the thermoelectric element of this example, two different kinds of metals are coupled at one end, and terminals for extracting an electromotive force are connected to the other uncoupled ends. The coupling portion and each other end are installed in the cold water tank 42 and the hot water tank 44, respectively. Here, the cold water in the cold water tank 42 and the hot water in the hot water tank 44 cause a temperature difference between the coupling portion and each other end, so that the thermoelectric element generates an electromotive force according to the temperature difference. The generated electromotive force is taken out to the outside by a terminal connected to each other end, subjected to appropriate transformation, and then supplied to the home. Thus, the fuel cell exhaust heat utilization system 100 of this example can obtain electric power using a thermoelectric element.

  In addition, since the thermoelectric element generates a larger electromotive force when the temperature difference is large, it is preferable that the coupling portion of the thermoelectric element and each of the other ends are provided at locations where the temperature difference is large. For example, the coupling portion of the thermoelectric element and each of the other ends may be provided below the cold water tank 42 and above the hot water tank 44, respectively. Thereby, the thermoelectric element can obtain larger electric power. Note that each of the coupling portion and each of the other ends may be appropriately provided in either the cold water tank 42 or the hot water tank 44 depending on the direction of the generated electromotive force. Thus, by using the thermoelectric element, the fuel cell exhaust heat utilization system 100 can obtain electric power using the temperature difference power generation device 46 having a simpler configuration.

  FIG. 3 shows a building 800 equipped with a fuel cell exhaust heat utilization system 105 according to another embodiment of the present invention. The fuel cell exhaust heat utilization system 105 includes a fuel cell 40, a hot water storage tank 67, a cold water pipe 50, a hot water pipe 52, a water pipe 48, a control unit 54, two temperature sensors 57 and 59, and a temperature difference power generation device 80. The temperature difference power generation device 80 includes a working medium circulation pump 69, an evaporator 64, a working medium pipe 70, a turbine 72, a generator 76, and a condenser 66. In FIG. 3, the components denoted by the same reference numerals as those in FIG. 1 have the same or similar functions as the components in FIG.

  A working medium pipe 70 included in the temperature difference power generation device 80 is connected in series with an evaporator 64, a turbine 72, a condenser 66, and a working medium circulation pump 69 in this order. Here, the evaporator 64 is disposed inside the fuel cell 40, and the condenser 66 is disposed inside the hot water storage tank 67. The working medium pipe 70 has a working medium therein, and the working medium circulation pump 69 converts the working medium contained in the working medium pipe 70 into a condenser 66, a working medium circulation pump 68, It is circulated through the evaporator 64, the evaporator 62, and the turbine 72.

  The condenser 66 of this example is disposed inside the hot water storage tank 67. Thereby, the condenser 66 condenses the evaporated working medium using the water stored in the hot water storage tank 67. In this case, the condenser 66 is arranged inside the hot water storage tank 67 so that the working medium circulates from the upper part to the lower part of the hot water storage tank 67. Warm hot water is stored in the upper part of the hot water storage tank 67, and colder water is stored in the lower part of the hot water storage tank 67, so that the evaporated working medium can be efficiently condensed. The working medium circulation pump 69 sends the liquid working medium to the evaporator 64.

  The evaporator 64 is disposed inside the fuel cell 40. The evaporator 64 uses the exhaust heat from the fuel cell 40 to evaporate the condensed working medium. The working medium pipe 70 supplies the evaporated working medium to the turbine 72. The vaporized working medium is sent to the condenser 66 through the working medium pipe 70 and is condensed again by the water in the hot water storage tank 67. Thus, the temperature difference power generation device 80 of the present invention generates power using the temperature difference between the fuel cell 40 and the hot water storage tank 67 and discharges the heat generated in the fuel cell 40 to the hot water storage tank 67.

  The hot water storage tank 67 is connected to the hot water pipe 52 at the upper part and to the cold water pipe 50 and the water pipe 48 at the lower part. Here, the water pipe 48 is connected to the hot water storage tank 67 further below the cold water pipe 50. In this case, the hot water storage tank 67 stores water at a higher temperature from the lower part of the hot water storage tank 67 toward the upper part of the hot water storage tank 67. Since the hot water pipe 52, the cold water pipe 50, and the water pipe 48 are arranged in this order from the upper part to the lower part of the hot water storage tank 67, the hot water pipe 52 can provide hot water to the user, and the cold water pipe. 50 can provide the user with colder water than the hot water supplied by the hot water pipe 52.

  The temperature sensor 57 measures the temperature of the cold water in the hot water storage tank 67, and the temperature sensor 59 measures the temperature inside the fuel cell 40. The control unit 54 controls the operation of the fuel cell 40 and the temperature difference power generator 80 based on the temperature of the water stored in the hot water storage tank 67 and the temperature inside the fuel cell 40. Details of the control will be described with reference to FIG.

FIG. 4 is a state diagram showing an example of the operation of the fuel cell exhaust heat utilization system 105. The control unit 54 of this example calculates the amount of heat of the hot water storage tank 67 based on the temperature Td of the hot water storage tank 67. As an example, the control unit 54 calculates the amount of heat of the control unit 54 by multiplying the value obtained by subtracting the temperature supplied by the water pipe 48 from the temperature Td of the hot water storage tank 67 by the amount of stored hot water. Further, the control unit 54 has a reference value Q ₁ for the amount of heat of the hot water storage tank 67 in advance. Incidentally, the reference value to Q ₁ heat may be a maximum amount of heat that can store the exhaust heat of the fuel cell 40 in the hot water storage tank 67 as hot water, hot water storage exhaust heat of the fuel cell 40 as a hot water tank 67 It may be the amount of heat obtained by subtracting a predetermined amount of heat from the maximum amount of heat that can be stored.

Here, the power consumption P of the current home, greater than the maximum power P ₃ that can be the fuel cell 40 generates electric power, and quantity Q of the hot water storage tank 67 is a smaller than Q _1, and, temperature Tc of the fuel cell 40, be only a temperature above T ₁ predetermined temperature than the boiling point of the working medium and the temperature Td of the hot water storage tank 67, a predetermined temperature above the boiling point of the working medium only lower temperature T ₂ In the following cases, the control unit 54 generates power with the fuel cell 40 and the temperature difference power generation device 80.

Further, the power consumption P is a P ₃ or less, and when the amount of heat Q of the hot water storage tank 67 is less than Q ₁ is, regardless of the temperature Td of the temperature Tc and the hot water storage tank 67 of the fuel cell 40, the control unit 54 Then, the power generation of the temperature difference power generation device 80 is stopped and the fuel cell 40 generates power.

Alternatively, when the heat quantity Q of the hot water storage tank 67 is smaller than Q ₁ and the temperature Tc of the fuel cell 40 is lower than T ₁ or the temperature Td of the hot water storage tank 67 is higher than T _2. The control unit 54 stops the power generation of the working medium pipe 70 and causes the fuel cell 40 to generate power. In this example, when the power generation of the temperature difference power generation device 80 is stopped, the control unit 54 stops the power generation by the generator 76, but does not stop the circulation of the working medium by the working medium circulation pump 69. In this example, the temperature T ₁ is 10 ° C. higher than the boiling point of the working medium, and the temperature T ₂ is 10 ° C. lower than the boiling point of the working medium. Therefore, the temperature difference power generator 80 cannot generate power using the temperature difference. Even in this case, the fuel cell exhaust heat utilization system 105 can continue the power generation by the fuel cell 40 by circulating the working medium inside the working medium pipe 70.

Then, had when heat Q of the hot water storage tank 67 is greater than Q ₁ is, the control unit 54 stops the power generation of the fuel cell 40 and the temperature difference power generator 80. As described above, the fuel cell exhaust heat utilization system 105 of the present invention can further obtain electric power by utilizing the exhaust heat of the fuel cell 40. When there is no demand for power, neither the fuel cell 40 nor the temperature difference power generation device 80 generates power.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements are also included in the technical scope of the present invention.

1 shows a building 800 equipped with a fuel cell exhaust heat utilization system 100 according to an embodiment of the present invention. 3 is a state diagram showing an example of the operation of the fuel cell exhaust heat utilization system 100. FIG. 1 shows a building 800 with a fuel cell waste heat utilization system 105 according to another embodiment of the invention. It is a state diagram showing an example of operation of fuel cell exhaust heat utilization system 105.

Explanation of symbols

DESCRIPTION OF SYMBOLS 40 ... Fuel cell, 42 ... Cold water tank, 44 ... Hot water tank, 46 ... Temperature difference power generation device, 48 ... Water pipe, 50 ... Cold water piping, 51 ... Connection piping 52 ... Hot water piping, 54 ... Control unit, 56, 57, 58, 59 ... Temperature sensor, 60 ... Fuel cell cooling pump, 62 ... Evaporator, 64 ... Evaporation , 66 ... condenser, 67 ... hot water storage tank, 68, 69 ... pump for working medium circulation, 70 ... piping for working medium, 72 ... turbine, 76 ... generator, 80 ... Temperature difference power generator, 100, 105 Fuel cell exhaust heat utilization system, 800 ... Building

Claims (9)

A fuel cell;
A cold water tank for storing cold water supplied from a water pipe;
Cold water piping for supplying cold water from the cold water tank;
A hot water tank for storing hot water generated by the fuel cell;
Hot water piping for supplying hot water to the home from the hot water tank;
A fuel cell exhaust heat utilization system comprising: a temperature difference power generation device that generates power using a temperature difference between hot water stored in the hot water tank and cold water stored in the cold water tank.   The fuel cell exhaust heat utilization system according to claim 1, wherein the cold water tank is connected to the cold water pipe at an upper side. The fuel cell waste heat utilization system according to claim 1 or 2, wherein the cold water tank is connected to the water pipe at a lower side. The fuel cell exhaust heat utilization system according to any one of claims 1 to 3, wherein the cold water tank is open to both the cold water pipe and the water pipe. The fuel cell exhaust heat utilization system according to any one of claims 1 to 4, wherein an upper part of the cold water tank is connected to a lower part of the hot water tank. The fuel cell waste heat utilization system according to any one of claims 1 to 5, wherein the hot water tank is open to the cold water tank. The hot water tank is provided integrally with the cold water tank on the cold water tank,
The fuel cell exhaust heat utilization system according to any one of claims 1 to 6 , wherein the cold water pipe is connected to the cold water tank above the water pipe and below the hot water pipe. A fuel cell;
A cold water tank for storing cold water supplied from a water pipe;
Cold water piping for supplying cold water from the cold water tank;
A hot water tank for storing hot water generated by the fuel cell;
Hot water piping for supplying hot water to the home from the hot water tank;
A building comprising a temperature difference power generation device that generates power using a temperature difference between hot water stored in the hot water tank and cold water stored in the cold water tank. The hot water tank is provided integrally with the cold water tank on the cold water tank,
The building according to claim 8 , wherein the cold water pipe is connected to the cold water tank above the water pipe and below the hot water pipe.

Images