JP4820115B2 - Heat storage system - Google Patents

Description

  The present invention relates to a heat storage system and a building. In particular, the present invention relates to a heat storage system and a building that store heat in the basement of the building at low cost.

As a cogeneration system that supplies electric power and hot water to a load from a cogeneration device, there is a system that determines the number of operating cogeneration devices based on the power consumption state and the hot water consumption state (for example, a patent) Reference 1). In this system, hot water heated by heat generated during fuel cell power generation is stored in a hot water storage tank, and the stored hot water is supplied to a hot water supply load.
JP 2003-199254 A

  The amount of hot water consumed in a house varies greatly from season to season or from day to day. If the adjustment of the number of operating heat / electricity supply devices and the amount of power generation is repeated in order to cope with such fluctuations in the consumption of hot water, the energy efficiency of the heat / electricity supply device will decrease. If a large-capacity hot water storage tank or a burner that generates hot water is installed in order to respond to fluctuations in the consumption of hot water while avoiding such a decrease in energy efficiency, the equipment costs for the hot water storage tank and burner will increase. Therefore, it is not preferable. Therefore, it is desirable that the cogeneration system is provided with a heat storage system that can store a larger amount of heat at a low cost from the heat and power supply device.

  Then, an object of this invention is to provide the thermal storage system and building which can solve said subject. This object is achieved by a combination of features described in the independent claims. The dependent claims define further advantageous specific examples of the present invention.

  A heat storage system according to a first aspect of the present invention includes a distributed power source that generates electric power and heat, a building that is supplied with electric power and heat from the distributed power source, and a building provided below the building. Underground piles to support and heat storage pipes installed near the outer periphery of the underground piles that store heat in the underground part below the building by flowing a heat medium heated by the amount of heat generated by the distributed power source With.

  The underground part has an aquifer that allows water to pass through and an impermeable layer that is below the aquifer and that is less likely to pass water than the aquifer, surrounds underground piles, and is impervious at least from below the building. It further includes an underground wall that reaches the layer and is less likely to pass water than the aquifer, and the heat storage pipe is located above the impermeable layer. The underground wall is a mountain stop that prevents the excavated wall from collapsing when excavating the underground.

  The underground part is more robust than the impermeable layer, has a supporting ground below the impermeable layer, the underground pile reaches the supporting ground, and the heat storage pipe is above the impermeable layer To position. A plurality of underground piles are provided below the building, and the heat storage pipes are provided on the underground piles inside the underground pile adjacent to the underground wall.

  When the amount of heat generated by the distributed power source is greater than the amount of heat consumed by the heat load, the control unit further stores heat in the underground portion by flowing a heat medium heated by the amount of heat generated by the distributed power source through the heat storage pipe. . When the amount of heat generated by the distributed power source is less than the amount of heat consumed by the heat load, the control unit applies a heat medium having a temperature lower than that of the heat medium heated by the heat amount of the distributed power source to the heat storage piping. The amount of heat of the heated heating medium is supplied to the heat load.

  In order to supply heat to the heat load, it is further provided with a hot water storage tank for storing hot water heated by the heat generated by the distributed power source, the heat storage pipe is connected to the hot water storage tank, and the control unit is connected to the hot water storage tank. When the amount of heat cannot be stored further, the hot water stored in the hot water storage tank is poured into the heat storage piping to store heat in the basement, and when the amount of heat stored in the hot water storage tank is less than the amount of heat required by the heat load, The water flowing through the heat storage pipe is heated by the amount of heat accumulated in the hot water, and the hot water obtained by heating is supplied to the hot water storage tank.

  The heat storage pipe is connected to a lower outlet for extracting hot water in the lower part of the hot water tank and an upper outlet for extracting hot water above the lower part in order to circulate the hot water in the hot water tank. When the amount of heat cannot be stored further, the hot water taken from the upper outlet is made to flow through the heat storage piping to provide heat to the underground, and then the hot water is returned from the lower outlet to the hot water tank and the amount of heat stored in the hot water tank When the amount of heat is less than the amount of heat required by the heat load, hot water is taken out from the lower outlet to the heat storage pipe and heated with the amount of heat accumulated in the basement, and the heated hot water is supplied from the upper outlet to the hot water tank To do.

  A hot water tank that stores hot water heated by the amount of heat generated by the distributed power source to supply heat to the heat load, a heat medium that is connected to the heat storage pipe and flows through the heat storage pipe, and hot water stored in the hot water tank And a heat exchanging unit that exchanges the amount of heat between the heat storage unit and the control unit, when the amount of heat cannot be further stored in the hot water storage tank, the heat medium heated by the hot water in the hot water storage tank through the heat exchange unit. If the amount of heat stored in the hot water storage tank is less than the amount of heat required by the heat load, the heat medium flowing through the heat storage piping is heated by the amount of heat stored in the basement. The warm water in the hot water tank is heated through the heat exchange unit.

  A hot water circulation pipe that circulates the hot water in the hot water tank is further connected by connecting a lower outlet for taking hot water at the lower part of the hot water tank and an upper outlet for taking hot water above the lower part. When the amount of heat cannot be further stored, the heat medium flowing through the heat storage pipe is heated by the hot water taken out from the upper outlet to the hot water circulation pipe through the heat exchange unit, and the amount of heat stored in the hot water storage tank is reduced by the heat load. When the amount of heat is less than the required amount of heat, the hot water taken out from the lower outlet to the hot water circulation pipe is heated by the heat medium flowing through the heat storage pipe via the heat exchange section.

  The distributed power source may be a fuel cell.

  According to the second aspect of the present invention, the building is supplied with electric power and heat from a distributed power source, and is provided below the building to support the building. And a heat storage pipe through which a heat medium heated by the amount of heat generated by the distributed power source is provided.

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

  According to the present invention, it is possible to provide a heat storage system and a building that store heat in the basement at low cost.

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

  FIG. 1 shows an example of the configuration of the heat storage system 100. The heat storage system 100 supplies heat and electric power to an electric load 54 and a thermal load 56 provided in the building 110, respectively. The heat storage system 100 stores the amount of heat discharged from the fuel cell 40 in the basement below the building 110, collects the amount of heat from the basement, and supplies it to the heat load 56. Here, the building 110 means a built object including a station, a tower, and the like in addition to a general building such as a house, an apartment house, a building, and a factory. A plurality of buildings 110 may be provided, and the fuel cells 40 may be provided in a distributed manner in each of the buildings 110. In this case, each of the fuel cells 40 may be provided to supply power to the power load 54 of any building 110. The fuel cell 40 is an example of a distributed power source according to the present invention, and the distributed power source according to the present invention may be a device that generates electric power and heat, such as a gas engine or a gas turbine.

  The heat storage system 100 includes a fuel cell 40, an exhaust heat pipe 88, an exhaust heat pump 80, a hot water storage heat exchanging unit 72, a hot water storage pipe 76, a hot water storage pump 78, a hot water tank 58, a hot water supply pipe 52, a hot water circulation pipe 86, and a hot water circulation pump. 98, a heat exchange unit 70, a heat storage pipe 44, a heat medium circulation pump 99, an underground pile 46, an underground wall 42, a wattmeter 90, a control unit 50, and a building 110. The fuel cell 40 generates electric power and heat. The electric power generated by the fuel cell 40 is supplied to the electric power load 54. The power load 54 operates by consuming the power generated by the fuel cell 40.

  The fuel cell 40 may be, for example, a polymer electrolyte fuel cell (PEFC). The fuel cell 40 may generate power using hydrogen gas supplied from a reformer that generates hydrogen gas by reforming city gas, propane gas, or the like, and uses hydrogen gas supplied from outside as fuel. You may generate electricity. The fuel cell 40 discharges heat from the power generation cell along with power generation. When the fuel cell 40 has a reformer, the fuel cell 40 discharges heat that was not used in the reformer.

  The hot water storage tank 58 stores hot water heated by the heat generated by the fuel cell 40 in order to supply heat to the heat load 56. Specifically, the hot water storage tank 58 stores hot water heated by receiving the exhaust heat of the fuel cell 40. The fuel cell 40 is connected to both ends of an exhaust heat pipe 88 through which cooling water for cooling the exhaust heat of the fuel cell 40 flows. The exhaust heat pipe 88 is connected to the hot water storage heat exchanging section 72, and the cooling water heated by receiving the exhaust heat of the fuel cell 40 is supplied to the hot water storage heat exchanging section 72 by the exhaust heat pump 80. After cooling, the fuel cell 40 is supplied again as cooling water for cooling the fuel cell 40. The hot water storage tank 58 is connected with a hot water storage pipe 76 that connects the lower and upper parts of the hot water storage tank 58 via a hot water storage heat exchanging section 72. A hot water storage pump 78 is connected to the hot water storage pipe 76, and hot water taken out from the lower part of the hot water storage tank 58 is supplied to the hot water storage heat exchanging section 72 by the hot water storage pump 78, and the hot water storage heat exchanging section 72 uses the fuel cell. After the amount of heat is received from the cooling water that has received 40 exhaust heat and heated, it is supplied from the upper part of the hot water storage tank 58.

  The hot water stored in the hot water storage tank 58 is supplied to the thermal load 56 through the hot water supply pipe 52. The heat load 56 may be, for example, a water heater including a bath, a shower, and a wash surface, an air conditioner, and the like, and consumes hot water supplied from the hot water supply pipe 52. Note that the heat load 56 may be a hot water floor heater that warms the floor using hot water or the like, and uses the heat quantity extracted from the hot water and discharges the hot water whose temperature has dropped. Then, the heat load 56 may return the hot water whose temperature has decreased to the hot water storage tank 58 from the lower part of the hot water storage tank 58.

  The underground pile 46 is provided below the building 110 in order to support the building 110. A heat storage pipe 44 is provided inside the underground pile 46. The heat storage pipe 44 stores heat in the underground portion 48 below the building 110 by flowing a heat medium heated by the amount of heat generated by the fuel cell 40. The heat storage pipe 44 collects heat from the underground portion 48 by flowing a heat medium heated by the amount of heat stored in the underground portion 48. Specifically, the heat storage pipe 44 stores a heat medium that has received heat from hot water stored in the hot water storage tank 58 through the underground portion 48 and stores the heat in the underground portion 48. The heat storage pipe 44 supplies heat to the hot water storage tank 58 by flowing a heat medium heated by the heat stored in the underground portion 48.

  More specifically, the hot water storage tank 58 has a lower outlet 82 for taking out hot water in the lower part of the hot water tank 58 and an upper outlet 84 for taking out hot water above the lower part. The upper outlet 84 is connected by a hot water circulation pipe 86. The heat exchange unit 70 is connected to the hot water circulation pipe 86 and the heat storage pipe 44, and exchanges heat between the heat medium flowing through the heat storage pipe 44 and the hot water stored in the hot water storage tank 58. For example, the hot water stored in the hot water storage tank 58 is directed from the lower outlet 82 to the upper outlet 84 or from the upper outlet 84 to the lower outlet 82 by the hot water circulation pump 98 connected to the hot water circulation pipe 86. Flowing. Then, the heat exchanging unit 70 heats the heat medium flowing through the heat storage pipe 44 with the hot water taken out from the upper outlet 84 to the hot water circulation pipe 86. In addition, the heat exchanging unit 70 heats the hot water taken out from the lower outlet 82 to the hot water circulation pipe 86 with a heat medium flowing through the heat storage pipe 44.

  Then, when the amount of heat generated by the fuel cell 40 is larger than the amount of heat consumed by the heat load 56, the control unit 50 causes the heat medium heated by the amount of heat generated by the fuel cell 40 to flow through the heat storage pipe 44. The part 48 stores heat. In addition, when the amount of heat generated by the fuel cell 40 is less than the amount of heat consumed by the heat load 56, the control unit 50 uses a heat storage pipe with a heat medium having a temperature lower than that of the heat medium heated by the amount of heat of the fuel cell 40. The heat amount of the heated heat medium is supplied to the heat load 56.

  Specifically, when the amount of heat cannot be further stored in the hot water storage tank 58, the control unit 50 causes the heat medium heated by the hot water in the hot water storage tank 58 to flow through the heat storage pipe 44 through the heat exchange unit 70 and underground. The part 48 stores heat. In addition, when the amount of heat stored in the hot water storage tank 58 is less than the amount of heat required by the heat load 56, the heat medium flowing through the heat storage pipe 44 is heated by the amount of heat accumulated in the underground portion 48, and the heat exchange unit 70. The hot water in the hot water storage tank 58 is heated via the.

  More specifically, when the amount of heat cannot be further stored in the hot water storage tank 58, the control unit 50 converts the heat medium flowing through the heat storage pipe 44 by the hot water taken out from the upper outlet 84 into the hot water circulation pipe 86. Heat through 70. In addition, when the amount of heat stored in the hot water storage tank 58 is less than the amount of heat required by the heat load 56, the control unit 50 takes out from the lower outlet 82 to the hot water circulation pipe 86 by the heat medium flowing through the heat storage pipe 44. The heated water is heated through the heat exchange unit 70. For example, the control unit 50 controls the direction of the hot water flowing through the hot water circulation pipe 86 by the hot water circulation pump 98 to supply the hot water taken out from the upper outlet 84 to the heat exchange unit 70 and store the heat in the underground part 48. The case where the hot water taken out from the lower outlet 82 is supplied to the heat exchanging unit 70 and the amount of heat is recovered from the underground part 48 is selected.

  A plurality of heat storage pipes 44 may be provided. A plurality of heat storage pipes 44 may be provided with one heat medium circulation pump 99, and each of the heat storage pipes 44 may be provided with a heat medium circulation pump 99. In addition, the underground pile 46 has a heat storage pipe 44 provided to store heat in the underground portion 48 and other heat storage provided to collect the heat received from the underground portion 48 and store it in the hot water storage tank 58 as hot water. A pipe 44 may be provided.

  In addition, in the underground part 48 below the building 110, there are an aquifer 62 through which water passes and an impermeable layer 64 that is below the aquifer 62 and is less likely to pass water than the aquifer 62. . In the underground portion 48, there is a supporting ground 66 that is more robust than the impermeable layer 64 and is below the impermeable layer 64. The underground pile 46 reaches the support ground 66. The supporting ground 66 may be a gravel layer or the like existing below the impermeable layer 64.

  The underground wall 42 surrounds the underground pile 46 and reaches at least the impermeable layer 64 from below the building 110. The underground wall 42 is less likely to pass water than the aquifer 62. For example, the underground wall 42 may be made of concrete. And the heat storage piping 44 is located above the impermeable layer 64 inside the underground pile 46.

  Thus, since the underground wall 42 reaches the impermeable layer 64, the underground part 48 surrounded by the underground wall 42 and the impermeable layer 64, and the aquifer 62 outside the underground wall 42, Access to and from the water is blocked. Furthermore, since the heat storage pipe 44 is located above the impermeable layer 64, the underground wall 48 is submerged from the underground portion 48 by the water of the aquifer 62 compared to the case where the underground pile 46 is not surrounded by the underground wall 42. The amount of heat that is carried to the outside of 42 can be reduced. Accordingly, the amount of heat can be kept in the underground part 48 for a long period of time.

  In addition, the underground wall 42 may be a mountain stop which prevents the wall surface formed by excavation from collapsing when excavating the underground part 48. For example, a mountain stopper built when the underground part 48 is excavated at the time of building the building 110 is made to reach the impermeable layer 64. And the cost which installs the underground wall 42 separately can be reduced by using the said mountain retaining as the underground wall 42. FIG. Moreover, the underground wall 42 may be a mountain retaining when excavating the ground, and may support the building 110 at the same time. For example, the underground wall 42 formed by inserting a steel frame or a reinforcing bar to support the building 110 in the concrete poured while drilling the ground may be used as a mountain stop. In this case, it is desirable that the underground wall 42 reaches the support ground 66 below the impermeable layer 64.

  In addition, it is good also considering the foundation of the lower part of the building 110 as a double floor, and the space enclosed by the double floor as the hot water storage tank 58. FIG. Further, each of the plurality of spaces surrounded by the double floor may be used as the hot water storage tank 58. Then, the hot water heated by the exhaust heat from the fuel cell 40 may be stored in the plurality of hot water storage tanks 58. Then, the control unit 50 may sequentially store hot water in the other hot water storage tanks 58 when it is no longer possible to store heat in one hot water storage tank 58.

  Moreover, the heat insulating material may be provided in the inner surface below the building 110 of the underground wall 42. Thereby, the amount of heat lost from the underground wall 42 to the outside can be reduced. In addition, the amount of heat lost from the underground wall 42 due to heat transfer to the building 110 can be reduced. In addition, the underground portion 48 below the building 110 may be provided with a heat storage body that stores heat.

  The water supply pipe 60 supplies water to the hot water storage tank 58. For example, when the heat load 56 is a hot water supply facility such as a shower and the like, and the hot water supplied from the hot water storage tank 58 is used and then the hot water after use is discharged to the outside of the hot water storage tank 58, the amount of discharged water is increased. Water is supplied to the hot water storage tank 58 through the water supply pipe 60. At this time, when the amount of heat stored in the hot water storage tank 58 is less than the amount of heat required by the heat load 56, the control unit 50 preheats clean water with the heat medium of the heat storage pipe 44 and then supplies the hot water to the hot water storage tank 58. You can do it. Specifically, the water supply pipe 60 supplies clean water to the hot water storage tank 58 via a water supply heat exchange section 74 to which a preheating pipe 75 branched from the heat storage pipe 44 is connected. The preheating pipe 75 is connected to the heat storage pipe 44 via a preheating valve 68 that controls the flow path of the heat medium of the heat storage pipe 44. When the control unit 50 preheats the clean water and supplies it to the hot water storage tank 58, the control unit 50 uses the preheating valve 68 to guide the heat medium of the heat storage pipe 44 to the preheating pipe 75, and heats it in the heat supply heat exchanger 74. Heat the water by heat exchange between the medium and the water. The preheating valve 68 is connected to a bypass pipe 43 that bypasses the heat medium of the preheating pipe 75 without supplying it to the heat exchange unit 70. The heat storage pipe 44 is provided with a backflow prevention valve 69 that prevents the heat medium from the bypass pipe 43 from being supplied to the heat exchanging section 70 at the connection portion with the bypass pipe 43. When the controller 50 preheats the clean water and supplies it to the hot water storage tank 58, the controller 50 closes the backflow prevention valve 69 and guides the heat medium from the bypass pipe 43 to the underground part 48, and the heat is stored in the underground part 48. The heating medium is heated by the amount of heat. Thereby, for example, in the winter season when demand for hot water supply expands, the water can be preheated by the amount of heat stored in the underground portion 48 and supplied to the hot water storage tank 58.

  According to the heat storage system 100 described above, when the amount of heat generated by the fuel cell 40 is larger than the amount of heat required by the heat load 56, even if heat cannot be stored as hot water in the hot water storage tank 58, the excess amount of heat is reduced. The underground part 48 can store heat. Further, since the fuel cell 40 can be continuously cooled, the fuel cell 40 can be stably driven without being stopped. When the amount of heat generated by the fuel cell 40 is smaller than the amount of heat consumed by the heat load 56, the amount of heat stored in the underground portion 48 can be recovered in the hot water storage tank 58 and provided to the heat load 56.

  Note that the control unit 50 may manage the history of the power consumption of the power load 54 and the heat consumption of the heat load 56. The control unit 50 detects the amount of power supplied from the fuel cell 40 to the power load 54 with the wattmeter 90 and stores it as a history of power consumption. Further, the control unit 50 calculates the amount of heat consumed by the heat load 56 based on the amount of hot water supplied from the hot water storage tank 58 to the heat load 56 and the temperature of the hot water, and stores it as a history of heat consumption. Keep it. Then, the control unit 50 predicts the amount of heat that the fuel cell 40 will generate in the future and the amount of heat that the heat load 56 will consume in the future based on the history of the power consumption and the amount of heat consumed.

  Moreover, the control part 50 calculates the calorie | heat amount which the hot water currently stored in the hot water storage tank 58 has by measuring the spatial distribution of the temperature of the hot water stored in the hot water storage tank 58, for example. The control unit 50 stores heat as hot water in the hot water storage tank 58 based on the amount of heat of hot water currently stored in the hot water storage tank 58, the amount of heat generated in the future by the fuel cell 40, and the amount of heat consumed by the heat load 56 in the future. It is determined whether or not the amount of heat required by the heat load 56 can be supplied from the hot water storage tank 58 by calculating the amount of heat. In this way, the control unit 50 can determine in advance whether or not the amount of heat generated by the fuel cell 40 is less than the amount of heat consumed by the heat load 56. When the control unit 50 determines that the amount of heat required by the heat load 56 cannot be supplied from the hot water storage tank 58, the control unit 50 controls the hot water circulation pump 98 to recover the heat amount from the underground part 48 to the hot water storage tank 58. Thus, the amount of heat required by the heat load 56 is stored in the hot water storage tank 58.

  FIG. 2 shows an example of a cross section of the underground pile 46. The underground pile 46 includes concrete having a heat storage pipe 44 and a reinforcing bar 94 therein. The heat storage pipe 44 is provided in the vicinity of the outer periphery inside the underground pile 46. Specifically, the heat storage pipe 44 is provided in a region 95 outside the region 96 where the strength for supporting the building 110 can be secured. For this reason, the underground pile 46 can provide heat to the underground portion 48 more efficiently than the case where the heat storage pipe 44 is provided on the inner side of the underground pile 46 and supports the building 110. It is possible to ensure the strength to do this.

  Further, when the underground pile 46 is constructed, a region including the region 95 that is wider than the region 96 in which the strength capable of supporting the building 110 is secured is excavated. And the underground pile 46 is built by arrange | positioning the reinforcement 94 and the thermal storage piping 44 in the area | region 96 and the area | region 95, respectively, and pouring concrete etc. into it. For this reason, the cost which installs the thermal storage piping 44 in the inside of the underground pile 46 can be reduced, ensuring the intensity | strength which supports the building 110. The heat storage pipe 44 may be, for example, a resin pipe made of cross-linked polyethylene, vinyl chloride, or the like having excellent heat resistance and corrosion resistance.

  The underground pile 46 may have one heat storage pipe 44a. For example, the heat medium that has passed through the heat exchanging unit 70 passes through the pipe cross section 45a, turns the inside of the underground pile 46 at a position above the impermeable layer 64, and passes through the pipe cross section 45b to exchange heat. Returned to unit 70. The underground pile 46 may include a plurality of heat storage pipes (44a and 44b). For example, the heat medium flowing through the heat storage pipe 44b passes through the pipe cross section 45d by passing through the pipe cross section 45c, folding back the inside of the underground pile 46 at a position above the impermeable layer 64. Further, the control unit 50 may determine the number of heat storage pipes 44 through which the heat medium should flow based on the amount of heat to be stored in the underground portion 48 or the amount of heat to be recovered from the underground portion 48. Further, the heat storage pipe 44 may be arranged in a spiral shape around the center of the underground pile 46 in the vicinity of the outer periphery of the underground pile 46.

  FIG. 3 shows an example of the arrangement of the underground piles 46. A plurality of underground piles 46 are provided below the building 110. And the heat storage piping 44 is provided in the underground pile (46a-46f) inside the underground pile 46 (for example, underground pile 46g) adjacent to the underground wall 42. As shown in FIG. For this reason, the amount of heat lost from the underground part 48 to the outside of the building 110 rather than the underground wall 42 can be reduced.

  The underground wall 42 may be provided with an underground wall 42b that divides the underground portion 48 below the building 110 into a plurality of partial areas, in addition to the underground wall 42a surrounding the outer periphery of the building 110. . In the example of FIG. 3, the underground portion 48 below the building 110 further includes a partial region 92a including the underground pile 46a and the underground pile 46b, the underground pile 46c, and the underground pile 46d by the underground wall 42b. It is divided into a partial region 92b and a partial region 92c including the underground pile 46e and the underground pile 46f. And the control part 50 gives priority to the underground part 48 of the partial area 92b most insulated from the exterior rather than the building 110 of the underground wall 42 over the underground part 48 of the other partial area 92a and the partial area 92c. The amount of heat of the fuel cell 40 may be stored. Note that the term “priority” as used herein may mean that heat is stored using the heat storage pipe 44 prior to the other partial area 92, and a larger amount of heat is used by the heat storage pipe 44 than the other partial area 92. It may mean that it is provided.

  FIG. 4 shows another example of a method of storing heat in the underground part 48 and / or recovering the amount of heat from the underground part 48. In the example of FIG. 4, the heat storage pipe 44 is connected to a hot water tank 58. Specifically, the heat storage pipe 44 is connected to the lower outlet 82 and the upper outlet 84. The heat medium circulation pump 99 causes the heat storage pipe 44 to flow using the hot water stored in the hot water storage tank 58 as a heat medium.

  When the amount of heat cannot be further stored in the hot water storage tank 58, the control unit 50 stores the hot water stored in the hot water storage tank 58 through the heat storage pipe 44 and stores the heat in the underground part 48. Further, when the amount of heat stored in the hot water storage tank 58 is less than the amount of heat required by the heat load 56, the control unit 50 heats the water flowing through the heat storage pipe 44 by the amount of heat accumulated in the underground portion 48, Warm water obtained by heating is supplied to the hot water storage tank 58.

  Specifically, when the amount of heat cannot be further stored in the hot water storage tank 58, the control unit 50 causes the hot water taken out from the upper outlet 84 to flow into the heat storage pipe 44 to provide the underground unit 48 with the amount of heat, and then takes the lower intake. Hot water is supplied from the outlet 82 to the hot water tank 58. In addition, when the amount of heat stored in the hot water storage tank 58 is less than the amount of heat required by the heat load 56, the control unit 50 takes hot water from the lower outlet 82 into the heat storage pipe 44 and accumulates it in the underground portion 48. Heated by the amount of heat, the heated hot water is supplied from the upper outlet 84 to the hot water storage tank 58. For example, the control unit 50 changes the direction of the hot water flowing through the heat storage pipe 44 by the heat medium circulation pump 99, thereby storing heat by supplying hot water taken out from the upper outlet 84 to the underground part 48, and lower outlet The recovery of the heat quantity from the underground part 48 by supplying the warm water taken out from 82 to the underground part 48 is selected.

  Note that when the heat load 56 is a hot water supply facility such as a shower and the like, and the hot water supplied from the hot water storage tank 58 is used and then the hot water after use is discharged outside the hot water storage tank 58, the amount of discharged water Clean water flows through the water supply pipe 60 and is supplied to the hot water storage tank 58. At this time, when the amount of heat stored in the hot water storage tank 58 is less than the amount of heat required by the heat load 56, the control unit 50 does not supply the hot water directly to the hot water storage tank 58 and supplies the hot water to the heat storage pipe 44. The hot water may be supplied to the hot water storage tank 58 after being preheated by the amount of heat guided and stored in the underground portion 48. Specifically, the water supply pipe 60 is connected to a preheating valve 68 provided in the heat storage pipe 44, and the control unit 50 guides clean water from the water supply pipe 60 to the heat storage pipe 44 using the preheating valve 68. . At this time, the control unit 50 closes the water supply blocking valve 67 that blocks the direct flow of clean water into the hot water storage tank 58 and removes the hot water from the hot water storage tank 58 from the lower outlet 82. Use to stop. Thereby, for example, in the winter season when demand for hot water supply expands, the water can be preheated by the amount of heat stored in the underground portion 48 and supplied to the hot water storage tank 58. In addition, the control part 50 does not supply hot water directly to the hot water storage tank 58 on the further conditions that the temperature of the warm water of the lower part of the hot water storage tank 58 is higher than the temperature of clean water, but guides fresh water to the heat storage piping 44. Then, after preheating with the amount of heat stored in the underground portion 48, the hot water tank 58 may be supplied. Thereby, the hot water storage efficiency of the hot water storage tank 58 can be increased.

  For example, when it is predicted that the amount of heat stored in the hot water storage tank 58 will be insufficient in the future, it is necessary to store as much hot water as possible in the hot water storage tank 58. And when the hot water storage tank 58 is filled with warm water, the temperature of the hot water in the lower part of the hot water storage tank 58 may be higher than the temperature of the clean water. In such a case, if the amount of clean water consumed by the heat load 56 is directly supplied to the lower part of the hot water storage tank 58, the hot water in the lower part of the hot water tank 58 and the hot water are mixed and the temperature is lowered. Cannot store hot water. In such a case, the hot water can be stored in the hot water storage tank 58 more efficiently by being heated in the underground part 48 and then supplied to the hot water storage tank 58.

  FIG. 5 shows another example of storing heat in the underground portion 48. The heat exchange unit 70 is connected to the exhaust heat pipe 88, and the heat medium flowing through the heat storage pipe 44 is heated by the amount of cooling water flowing through the exhaust heat pipe 88. Then, the heat medium flowing through the heat storage pipe 44 stores heat in the underground part 48 by providing the underground part 48 with the amount of heat of the heated heat medium. The exhaust heat pipe 88 is connected to the hot water storage heat exchanging unit 72 and the heat exchanger so as to supply cooling water to the heat exchanging unit 70 after the hot water storage heat exchanging unit 72 in the path of the cooling water flowing through the exhaust heat pipe 88. Connected to the unit 70. As a result, the cooling water flowing through the exhaust heat pipe 88 provides heat to the hot water storage tank 58 in the hot water storage heat exchanging section 72, and then provides heat to the heat medium flowing through the heat storage pipe 44 in the heat exchanging section 70. To do. Therefore, if the exhaust heat of the fuel cell 40 cannot be provided to the hot water storage tank 58, for example, when the hot water storage tank 58 is filled with hot water, the exhaust heat of the fuel cell 40 is automatically stored in the underground portion 48. It will be. Further, even when the cooling water flowing through the exhaust heat pipe 88 is not sufficiently cooled in the hot water storage heat exchanging portion 72, the cooling water can be further cooled in the heat exchanging portion 70, so that the fuel cell 40 is stably operated. be able to.

  Further, the control unit 50 may stop the hot water storage pump 78 when the amount of heat cannot be stored in the hot water storage tank 58 further. As a result, energy for driving the hot water storage pump 78 is not wasted. Further, the control unit 50 may stop the heat medium circulation pump 99 when it is not necessary to store the amount of heat in the underground portion 48. Note that the exhaust heat pipe 88 may have a bypass pipe without going through the heat exchange unit 70. And the control part 50 may pass the said piping, without supplying cooling water to the heat exchange part 70, when it is not necessary to store heat quantity in the underground part 48. FIG.

  In the above description, as an example of the heat storage system 100, the form in which the exhaust heat of the fuel cell 40 is once stored in the hot water storage tank 58 as hot water has been described. In another example of the heat storage system 100, the hot water storage tank 58 is not provided, and the heat exhausting heat of the fuel cell 40 is heated directly or by the heat exchanging unit 70 by heating the heat medium circulating in the heat storage pipe 44. 48 may store heat.

  According to the heat storage system 100 described above, when the fuel cell 40 generates surplus heat that is not consumed by the heat load 56, the surplus heat can be stored in the underground portion 48 at low cost. When the amount of heat supplied from the fuel cell 40 is insufficient compared to the amount of heat consumed by the heat load 56, the amount of heat can be recovered from the underground portion 48 and used. Therefore, it is possible to reduce equipment costs such as a burner provided to preliminarily heat when the hot water supplied to the building 110 is insufficient. Further, in the heat storage system 100, the capacity of the hot water storage tank 58 can be made smaller, or the hot water storage tank 58 can be omitted, so that the equipment cost of the hot water storage tank 58 can be reduced and the installation space of the hot water storage tank 58 can be reduced. Can be saved.

  In the present embodiment, the fuel cell 40 is used as an example of an apparatus for supplying heat and electric power. However, instead of the fuel cell 40, fossil fuel and / or hydrogen gas such as a gas engine or a gas turbine is used. May be a device that generates electricity using as a fuel. Also in the example of such a heat storage system 100, the effect similar to the effect described in the above description can be acquired.

  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. Various modifications or improvements can be added to the above embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

1 is a diagram illustrating an example of a configuration of a heat storage system 100. FIG. It is a figure which shows an example of the cross section of the underground pile 46. FIG. It is a figure which shows an example of arrangement | positioning of the underground pile 46. FIG. It is a figure which shows another example of the heat storage to the underground part 48, and / or the recovery method of the calorie | heat amount from the underground part 48. FIG. It is a figure which shows the other example which accumulates heat in the underground part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Thermal storage system 110 Building 40 Fuel cell 42 Underground wall 43 Bypass piping 44 Thermal storage piping 46 Underground pile 48 Underground part 50 Control part 52 Hot water supply pipe 54 Electric power load 56 Thermal load 58 Hot water storage tank 60 Water supply pipe 62 Aquifer 64 Not Water-permeable layer 66 Support ground 67 Water supply prevention valve 68 Preheating valve 69 Backflow prevention valve 70 Heat exchange part 72 Hot water storage heat exchange part 74 Water supply heat exchange part 75 Preheating pipe 76 Hot water storage pipe 78 Hot water pump 80 Waste heat pump 82 Lower outlet 84 Upper outlet 86 Hot water circulation pipe 88 Waste heat pipe 90 Wattmeter 98 Hot water circulation pump 99 Heat medium circulation pump

Claims (5)

A distributed power source that generates power and heat, and
An underground pile that is provided below the building to which power and heat are supplied from the distributed power source and supports the building;
A heat storage pipe that is provided near the outer periphery inside the underground pile and stores heat in the underground part below the building by flowing a heat medium heated by the amount of heat generated by the distributed power source, and
A diaphragm wall having a ground stake viewed circumference, second underground wall which divides the first diaphragm wall and the underground surrounding an outer periphery of the building into a plurality of partial regions,
Of the plurality of partial regions of the underground part, a control unit that preferentially stores the amount of heat of the distributed power source in a partial region most insulated from the outside of the first underground wall over other partial regions; <br/>
The underground part includes an aquifer through which water passes, an impermeable layer that is below the aquifer and is less likely to pass water than the aquifer, and is more robust than the impermeable layer and from the impermeable layer. Also has a supporting ground at the bottom,
The underground wall reaches at least the impermeable layer from below the building and is less likely to pass water than the aquifer,
The underground pile reaches the supporting ground,
The heat storage piping is a heat storage system in which the heat storage pipe passes through the heat medium by being folded back above the impermeable layer. The heat storage system according to claim 1 , wherein a heat insulating material is provided on an inner surface of the underground wall. When the amount of heat generated by the distributed power source is greater than the amount of heat consumed by a heat load, the control unit causes the heat medium heated by the amount of heat generated by the distributed power source to flow through the heat storage pipe. The heat storage system of Claim 1 or 2 which stores heat in an underground part. A hot water storage tank for storing hot water heated by the amount of heat generated by the distributed power source to supply heat to the heat load;
The heat storage pipe is connected to the hot water tank,
When the control unit cannot further store the amount of heat in the hot water storage tank, the hot water stored in the hot water storage tank flows through the heat storage pipe to store heat in the underground part, and the heat stored in the hot water storage tank is stored in the heat storage tank. If less than the amount of heat required by the load, warmed water flowing in the heat storage pipes by accumulated heat in the underground, heated hot water obtained in claim 3 to be supplied to the hot water storage tank The described heat storage system. The heat storage pipe is connected to a lower outlet for taking out hot water in the lower part of the hot water tank and an upper outlet for taking out hot water above the lower part in order to circulate the hot water in the hot water tank,
When the control unit is unable to further store the amount of heat in the hot water storage tank, the hot water taken out from the upper outlet is allowed to flow through the heat storage pipe to provide heat to the underground part, and then the hot water storage from the lower outlet. When the hot water is returned to the tank, and the amount of heat stored in the hot water storage tank is less than the amount of heat required by the heat load, the amount of heat accumulated in the underground portion by extracting hot water from the lower outlet to the heat storage pipe The heat storage system according to claim 4 , wherein the hot water heated by is supplied to the hot water storage tank from the upper outlet.

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