JP2009115426A - Hot water supply system and hot water supply method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water supply system and a hot water supply method capable of carrying out miniaturization of the system. <P>SOLUTION: The hot water supply system is equipped with a first unit 12 having a heat pump 20 passing a first fluid, and a second unit 30 having tanks 34, 36 arranged with a heat storage material 100 and storing a second fluid at least temporarily. In the second unit 30, the second fluid is heated by heat transferred from at least one of the heat storage material 100 or the first fluid. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hot water supply system and a hot water supply method using a heat pump.

Since a hot water supply system equipped with a heat pump (heat pump circuit) uses the heat of the atmosphere, the energy utilization efficiency during water heating is relatively high compared to other general hot water heaters such as electric water heaters. Known (see, for example, Patent Documents 1 and 2).
JP 2004-28479 A JP 2005-16759 A

  Conventionally, heat pump hot water supply systems have a problem that the capacity of a hot water storage space (tank) is relatively large. In order to further spread the heat pump hot water supply system to general households, downsizing of the system is desired. In addition, further improvement in energy efficiency is desired.

  An object of the present invention is to provide a hot water supply system and a hot water supply method capable of downsizing the system.

  According to an aspect of the present invention, a first unit having a heat pump through which a first fluid flows, and a second unit having a tank in which a heat storage material is disposed and a second fluid is stored at least temporarily, the heat storage material and There is provided a hot water supply system comprising: the second unit that heats the second fluid by heat transferred from at least one of the first fluids.

  According to another aspect of the present invention, there is provided a hot water supply method using a heat pump and a heat storage material, the step of storing the heat from the heat pump in the heat storage material disposed in a tank, and the heat pump Storing the first hot water in the tank, supplying the first hot water stored in the tank to a predetermined facility, and supplying the second hot water heated by the heat storage material in the tank to the predetermined facility. There is provided a hot water supply method including a step of supplying and a step of supplying third hot water heated by the heat pump directly to the predetermined facility.

  According to the aspect of the present invention, it is possible to reduce the size of the system by using the heat storage material as compared with the conventional case.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing the first embodiment. In FIG. 1, a hot water supply system 10 includes a heat pump unit (first unit) 12 having a heat pump (heat pump circuit) 20 through which a working fluid (working medium, first fluid) flows, and a heated fluid (heated medium, second fluid). ) As a water supply unit (second unit) 30 and a control device 70. The control device 70 comprehensively controls the entire system. The configuration of the hot water supply system 10 can be variously changed according to design requirements.

  The heat pump 20 is a circuit that transfers heat between a plurality of objects by using a change in the state of the working fluid by a cycle including evaporation, compression, condensation, and expansion processes. Heat pumps generally have the advantage of being relatively energy efficient. In the present embodiment, the heat pump 20 pumps heat from the atmosphere and heats water using it as a heat source.

  In the present embodiment, the heat pump 20 includes a heat absorbing part 21, a compressing part 22, a heat radiating part (first heat radiating part 23A, second heat radiating part 23B), and an expanding part 24, which are connected via a conduit. Yes.

  In the heat absorption part 21, the working fluid flowing in the main path 25 absorbs the heat of the heat source outside the cycle. In this embodiment, the heat absorption part 21 of the heat pump 20 absorbs atmospheric heat. The heat absorption part 21 of the heat pump 20 can also be configured to absorb the heat of a heat source other than the atmosphere (for example, a cold energy supply device).

  The compression unit 22 compresses the working fluid by a compressor or the like. At this time, the temperature of the working fluid usually increases. The compressing unit 22 has a structure for compressing the working fluid into a single stage or a plurality of stages. The number of compression stages is set according to the specifications of the hot water supply system 10 and is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 or more. Among the various compressors such as an axial flow compressor, a centrifugal compressor, a reciprocating compressor, and a rotary compressor, a compressor suitable for compressing the working fluid is applied. Power is supplied to the compressor.

  In this embodiment, the compression part 22 has a structure which compresses a working fluid in multiple stages. The compression unit 22 shown in FIG. 1 has a two-stage compression structure including a first compression unit 22A and a second compression unit 22B. The compression unit 22 can have a multiaxial compression structure in which the rotation speeds corresponding to the compression units 22A and 22B are individually controlled. Alternatively, the compression unit 22 can have a coaxial compression structure. In the present embodiment, the compression unit 22 has a multi-axis structure corresponding to the compression units 22A and 22B, and power is supplied to each of the two shafts. The compression ratios (pressure ratios) of the compression units 22 </ b> A and 22 </ b> B are set according to the specifications of the hot water supply system 10.

  The heat radiating portions 23A and 23B have a conduit through which the working fluid compressed by the compressing portion 22 flows, and gives the heat of the working fluid flowing in the main path 25 to an object outside the cycle. In the present embodiment, the first heat radiating portion 23A and the second heat radiating portion 23B are arranged in that order along the flow direction of the working fluid. The number of heat radiation units is set according to the specifications of the hot water supply system 10 and is 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11 or more. The first heat radiating portion 23A is disposed at a downstream position of the second compression portion 22B, and the second heat radiating portion 23B is disposed at a downstream position of the first heat radiating portion 23A. Each of the heat radiating portions 23 </ b> A and 23 </ b> B is thermally connected to a part of the supply unit 30.

  The expansion unit 24 expands the working fluid by a pressure reducing valve, a turbine, or the like. When a turbine is used, power can be taken out from the expansion unit 24, and the power may be supplied to the compression unit 22, for example. As the working fluid used in the heat pump 20, various known heat media such as a chlorofluorocarbon medium (HFC 245fa, etc.), ammonia, water, carbon dioxide, air, and the like are used according to the specifications and heat balance of the hot water supply system 10. It is done. At least a part of the working fluid flowing through the heat radiating portions 22A and 22B of the heat pump 20 may be in a supercritical state.

  In the present embodiment, the heat pump 20 further includes a bypass path 27 and a regenerator 28. The inlet end of the bypass path 27 is fluidly connected to a conduit between the first heat radiating part 23A and the second heat radiating part 23B in the main path 25 of the heat pump 20. An outlet end of the bypass path 27 is fluidly connected to a pipe between the second heat radiation part 23 </ b> B and the expansion part 24 in the main path 25. A flow rate control valve for controlling the bypass flow rate of the working fluid can be provided at the inlet of the bypass passage 27. In the bypass path 27, part of the working fluid from the first heat radiating portion 23 </ b> A bypasses the second heat radiating portion 23 </ b> B and merges with the working fluid from the second heat radiating portion 23 </ b> B before the expansion portion 24. The remaining working fluid from the first heat radiating portion 23A flows through the second heat radiating portion 23B, and the heat from the second heat radiating portion 23B is transmitted to the water in the supply unit 30.

  The regenerator 28 has a configuration in which a part of the conduit of the bypass path 27 and a part of the conduit of the main path 25 of the heat pump 20 (the conduit between the heat absorption part 21 and the compression part 22) are thermally connected. Have. For example, both conduits are placed in contact with or adjacent to each other. In the heat pump 20, the working fluid from the first heat radiating unit 23 </ b> A is hotter than the working fluid from the heat absorbing unit 21. In the regenerator 28, the working fluid from the first heat radiating part 23 </ b> A flowing through the bypass path 27 and the working fluid from the heat absorbing part 21 flowing through the main path 25 of the heat pump 20 exchange heat. By this heat exchange, the temperature of the working fluid in the bypass path 27 is lowered, and the temperature of the working fluid in the main path 25 is raised. The regenerator 28 can have a countercurrent heat exchange structure in which a low-temperature fluid (working fluid in the main passage 25) and a high-temperature fluid (working fluid in the bypass passage 27) flow in opposition. Alternatively, the regenerator 28 may have a parallel flow type heat exchange structure in which a high-temperature fluid and a low-temperature fluid flow in parallel.

  The supply unit 30 includes a water supply source 15, a hot water storage tank 32, a first heat storage tank 34, and a second heat storage tank 36. The supply unit 30 further includes a conduit, a pump, and a valve as required. In the present embodiment, water from the supply source 15 is sent to the path 51 and / or the path 52 via the valve 41. Under the control of the control device 70, the flow rate of water flowing through the path 51 and the flow rate of water flowing through the path 52 are controlled via the valve 41 and / or other flow rate control means.

  The path 51 includes a first heating conduit 51A that is thermally connected to the second heat radiating portion 23B of the heat pump 20 and through which water from the supply source 15 flows, and a second heating conduit 51B. A first heat exchanger 61 is configured by the first heating conduit 51A and the second heat radiating portion 23B. The first heat exchanger 61 may have a countercurrent heat exchange method in which a low-temperature fluid (water in the first heating conduit 51A) and a high-temperature fluid (working fluid in the heat pump 20) flow in opposition. it can. Alternatively, the first heat exchanger 61 may have a parallel flow type heat exchange method in which a high-temperature fluid and a low-temperature fluid flow in parallel. In the present embodiment, various known ones can be adopted as the heat exchange structure of the first heat exchanger 61. The first heating conduit 51A and the conduit of the second heat radiating portion 23B are arranged in contact with or adjacent to each other. For example, the conduit of the second heat radiating portion 23B can be disposed on the outer peripheral surface or inside of the conduit of the first heating conduit 51A. Due to the heat transferred from the second heat radiating portion 23B of the heat pump 20, the temperature of the water in the first heating conduit 51A rises.

  Moreover, the 2nd heat exchanger 63 is comprised by the 2nd heating conduit | pipe 51B and the 1st thermal radiation part 23A. Similarly to the first heat exchanger 61, the second heat exchanger 63 has a direction in which a low-temperature fluid (water in the second heating conduit 51 </ b> B) and a high-temperature fluid (working fluid in the heat pump 20) face each other. It can have a flow-type heat exchange system. Alternatively, the second heat exchanger 63 may have a parallel flow type heat exchange method in which a high-temperature fluid and a low-temperature fluid flow in parallel. In the present embodiment, various known ones can be adopted as the heat exchange structure of the second heat exchanger 63. The second heating conduit 51B and the conduit of the first heat radiating portion 23A are disposed in contact with or adjacent to each other. For example, the conduit of the first heat radiating portion 23A can be disposed on the outer peripheral surface or inside of the conduit of the second heating conduit 51B. The heat in the second heating conduit 51B (hot water from the first heating conduit 51A) further rises in temperature due to the heat transferred from the first heat radiating portion 23A of the heat pump 20.

  The path 52 is fluidly connected to the first heat storage tank 34 and the second heat storage tank 36. Water from the valve 41 is sent to the first heat storage tank 34 and the second heat storage tank 36 via the path 52. The path 52 may include a valve that controls the amount of water supplied to the first heat storage tank 34 and the second heat storage tank 36.

  A valve 42 for controlling the amount of hot water supplied to the hot water storage tank 32 is disposed on the path 51. The arrangement position of the valve 42 is between the first heating conduit 51 </ b> A and the second heating conduit 51 </ b> B in the path 51. Path 53 is fluidly connected to path 51 via valve 42. The water whose temperature has increased in the first heat exchanger 61 is supplied to the hot water storage tank 32 via the path 53. Hot water stored in the hot water storage tank 32 is appropriately guided to a discharge pipe 54 fluidly connected to the hot water storage tank 32 through a valve (not shown).

  A valve 43 and a valve 44 for controlling the amount of hot water supplied to the first heat storage tank 34 and the second heat storage tank 36 are further arranged on the path 51, respectively. The arrangement position of the valve 43 that controls the amount of hot water supplied to the second heat storage tank 36 is a downstream position of the second heating conduit 51 </ b> B in the path 51. Similarly, the arrangement position of the valve 44 for controlling the amount of hot water supplied to the first heat storage tank 34 is also a downstream position of the second heating conduit 51B in the path 51. In FIG. 1, the valve 43 and the valve 44 may be integrated into one, and the positional relationship between the valve 43 and the valve 44 on the path 51 may be reversed to that of FIG.

  Branch paths 55 and 56 are fluidly connected to path 51 via valves 43 and 44, respectively. Water whose temperature has risen in the second heat exchanger 63 is supplied to the second heat storage tank 36 and the first heat storage tank 34 via the branch paths 55 and 56, respectively.

  As described above, in the first and second heat storage tanks 34 and 36, unheated water from the supply source 15 and heated water (hot water) from the first and second heat radiating units 23A and 23B are provided. It can be supplied.

  Furthermore, the working fluid from the first compression unit 22A can be supplied to the first heat storage tank 34. A valve 71 that selectively guides the working fluid from the first compression unit 22A to the first heat storage tank 34 or the second compression unit 22B is disposed in the path between the first compression unit 22A and the second compression unit 22B. The The working fluid compressed by the first compression unit 22 </ b> A is supplied to the first heat storage tank 34 via the valve 71 and the path 81. The working fluid from the first heat storage tank 34 is guided to a path between the first compression part 22A and the second compression part 22B via the path 82 and the valve 72.

  On the other hand, the working fluid from the second compression section 22B can be supplied to the second heat storage tank 36. A valve 73 that selectively guides the working fluid from the second compression unit 22B to the second heat storage tank 36 or the first heat dissipation unit 23A is disposed in the path between the second compression unit 22B and the first heat dissipation unit 23A. The The working fluid compressed by the second compression unit 22 </ b> B is supplied to the second heat storage tank 36 via the valve 73 and the path 83. The working fluid from the second heat storage tank 36 is guided to a path between the first heat radiating part 23A and the second heat radiating part 23B via the path 84 and the valve 74.

  A heat storage material 100 is disposed in the first and second heat storage tanks 34 and 36. The heat storage material 100 of the first heat storage tank 34 can store heat transferred from the working fluid from the first compression unit 22A. On the other hand, the heat storage material 100 of the second heat storage tank 36 can store the heat transferred from the working fluid from the second compression section 22B.

  The material characteristics of the heat storage material 100 are determined according to the specifications of the hot water supply system 10. In this embodiment, the heat storage material 100 includes a latent heat storage material (PCM: Phase Change Material) that stores and radiates heat with a liquid-solid phase change. That is, the heat storage material 100 stores heat when melting and dissipates heat when solidified. Melting | fusing point of a latent heat storage material is set according to the specification of the hot water supply system 10, for example, 20-30 degreeC, 30-40 degreeC, 40-50 degreeC, 50-60 degreeC, 60-70 degreeC, 70-80 degreeC, It is 80-90 degreeC, 90-100 degreeC, or 100 degreeC or more. Examples of the latent heat storage material include materials mainly composed of hydrocarbons such as erythritol and alkanes, wax systems (paraffin wax, microcrystalline wax, etc.), sodium acetate, sodium acetate trihydrate, or inorganic hydrate salts. It is done. Examples include the RUBITHERM RT series (registered trademark) manufactured by RUBITHRM, the PULSE ICE E series (registered trademark) manufactured by ENVIRONMENTAL PROCESS SYSTEMS, and the STL series (registered trademark) manufactured by Mitsubishi Chemical Engineering. The latent heat storage material has a small volume change accompanying a phase change (that is, a high stored energy density), and is advantageous for downsizing the apparatus. As the heat storage material 100, other materials such as a sensible heat storage material, a chemical reaction heat storage material, and a heat storage material using a supercritical fluid may be used.

  In the present embodiment, a plurality of containers 102 in which the heat storage material 100 is accommodated are arranged in the tanks 34 and 36. The plurality of containers 102 may have the same shape or different shapes. 2A and 2B are schematic cross-sectional views illustrating an example of the container 102 of the heat storage material 100. As shown in FIGS. 2A and 2B, the outer shape of each container 102 may have, for example, a substantially spherical shape or a substantially spherical shape having protrusions and / or depressions. The shape of the container 102 is not limited to the above example. The outer shape of each container 102 can have various shapes such as a substantially elliptical shape and a substantially rectangular shape. Since the container 102 has a shape in which the ratio of the surface area to the inner volume is relatively large, the heat exchange efficiency between the heat storage material 100 and another object can be improved.

  Returning to FIG. 1, the plurality of containers 102 are arranged relatively dispersed in the tanks 34 and 36. For example, the plurality of containers 102 are disposed at least partially spaced from each other. The compressed high-temperature working fluid from the first compression unit 22A or the second compression unit 22B can flow through the gaps between the plurality of containers 102 and / or the flow paths located in the gaps. In each of the tanks 34 and 36, the heat storage material 100 that has received heat from the working fluid changes from a solid to a liquid. In this embodiment, in each tank 34 and 36, each of the some container 102 in which the thermal storage material 100 was accommodated heat-exchanges with a working fluid. That is, since the heat storage material 100 (container 102) is distributed, the heat of the working fluid can be transmitted to the solid heat storage material 100 in a short time over almost the entire inside of each of the tanks 34 and 36. As a result, the entire heat storage material 100 in the tanks 34 and 36 changes in phase relatively uniformly, and the deviation of the phase change positions and / or partial phase change delays in the tanks 34 and 36 are suppressed.

  Moreover, the water from the supply source 15 and the path | route 52 can flow through the clearance gap between the some container 102 which has the liquefied thermal storage material 100, and / or the flow path located in the clearance gap. In each of the tanks 34 and 36, the heat storage material 100 can transmit heat to the low-temperature water. The water that has received the heat transferred from the heat storage material 100 rises in temperature and is appropriately guided to the discharge pipes 54 that are fluidly connected to the tanks 34 and 36 via valves (not shown).

  In the heat storage tanks 34 and 36, the heat storage material 100 deprived of heat changes from a liquid to a solid. Even in this phase change, due to the dispersive arrangement of the heat storage material 100 (container 102), the entire heat storage material 100 in the tanks 34 and 36 changes in phase relatively uniformly, and the phase change position in the tanks 34 and 36 is biased. // Partial phase change delay is suppressed.

  The heat storage material 100 changes in volume along with the phase change. In the present embodiment, since the heat storage material 100 is dispersedly arranged in the plurality of containers 102 in the tanks 34 and 36, the volume change of the heat storage material 100 in each container 102 is relatively small. Therefore, damage to the container 102 and the tanks 34 and 36 due to the volume change of the heat storage material 100 is prevented.

  The container 102 can be composed of various materials. For example, the container 102 can be made of a material having high rigidity or a deformable material (for example, a resin material). When the container 102 is deformed (for example, elastically deformed) in accordance with the volume change of the heat storage material 100, the container 102 and the tanks 34 and 36 due to the volume change of the heat storage material 100 are more reliably prevented.

  In addition, the shape, arrangement | sequence, material, etc. of the thermal storage tanks 34 and 36 and the container 102 can be set arbitrarily, and various aspects are applicable. In the present embodiment, the capacity (size) of the second heat storage tank 36 is set larger than that of the first heat storage tank 34, but the present invention is not limited to this. The plurality of containers 102 may be arranged at fixed positions in the tanks 34 and 36, or may be arranged to flow. A heat insulating material is disposed in the heat storage tanks 34 and 36 as necessary. The heat storage tanks 34 and 36 may have heat transfer promoting members such as fins as necessary.

  The control device 70 performs overall control of the hot water supply system 10 by controlling each device in the heat pump 20 and various piping devices including a pump and a valve. In addition to a calculation unit that performs calculation and control, A storage unit, an input / output unit, and the like are included. The hot water supply system 10 appropriately includes measuring instruments such as a temperature sensor and a flow rate sensor (not shown). The control device 70 performs the above control based on the measurement results of these measuring instruments, for example.

  Next, the operation of the hot water supply system 10 will be described. In the present embodiment, the hot water supply system 10 has at least a first heat storage mode, a second heat storage mode, a first hot water supply mode, a second hot water supply mode, and a third hot water supply mode. FIG. 3 is a diagram schematically showing a temperature change of the working fluid of the heat pump in the first heat storage mode. FIG. 4 is a diagram schematically showing a temperature change of the working fluid of the heat pump in the second heat storage mode and the third hot water supply mode. FIG. 5 is a diagram schematically illustrating a temperature change of water in the second hot water supply mode.

<First heat storage mode>
In the first heat storage mode, the heat pump 20 of the hot water supply system 10 is operated using, for example, nighttime power (midnight power). The operation of the heat pump 20 can be, for example, a time zone in which the power rate is set low. The energy cost can be reduced by using the power in such a time zone.

  In the first heat storage mode, the temperature of the working fluid compressed by the first compression unit 22A rises (m1 in FIG. 3). The valve 71 of the heat pump 20 guides the working fluid from the first compression unit 22 </ b> A to the first heat storage tank 34. The temperature of the compressed working fluid from the first compression unit 22A is, for example, about 90 ° C. In the first heat storage tank 34, the heat transferred from the working fluid is stored in the heat storage material 100. That is, as shown in FIG. 3A, the heat storage material 100 (PCM) in the container 102 is heated by the heat transmitted from the working fluid from the first compression unit 22A, and the heat storage material 100 changes from the solid phase to the liquid phase. Change. In the 1st heat storage tank 34, melting | fusing point of a latent heat storage material is about 50-65 degreeC, for example. The control device 70 comprehensively controls the system. In the first heat storage tank 34, the latent heat of fusion of the heat storage material 100 is stored as the heat storage material 100 is liquefied. In the first heat storage tank 34, the heat storage material 100 is deprived of heat, so that the temperature of the working fluid decreases.

  In the first heat storage mode, the working fluid from the first heat storage tank 34 whose temperature has dropped is introduced into the second compression unit 22B. The valve 73 guides the working fluid from the second compression unit 22 </ b> B to the second heat storage tank 36. The temperature of the compressed working fluid from the second compression unit 22B rises (m2 in FIG. 3). The temperature of the working fluid compressed by the second compression unit 22B is approximately the same as the temperature of the working fluid from the first compression unit 22A, and is about 90 ° C., for example. In the second heat storage tank 36, the heat transferred from the working fluid is stored in the heat storage material 100. That is, as shown in FIG. 3B, the heat storage material 100 in the container 102 is heated by the heat transmitted from the working fluid from the second compression section 22B, and the heat storage material 100 changes from a solid phase to a liquid phase. Also in the 2nd heat storage tank 36, melting | fusing point of a latent heat storage material is about 50-65 degreeC, for example. The control device 70 comprehensively controls the system. In the second heat storage tank 36, the latent heat of fusion of the heat storage material 100 is stored as the heat storage material 100 is liquefied.

  In the first heat storage mode, hot water is stored in the hot water storage tank 32 using the first heat exchanger 61 in parallel with the heat storage in the first and second heat storage tanks 34, 36. That is, as shown in FIG. 3C, water is introduced from the supply source 15 into the path 51 in the operating state of the heat pump 20. The water flowing through the first heating conduit 51A of the path 51 is heated by the heat transferred from the second heat radiating portion 23B. The valve 42 guides hot water from the second heat radiating unit 23 </ b> B to the hot water storage tank 32. The hot water is stored in the hot water storage tank 32. The temperature of water from the supply source 15 is, for example, about 20 ° C., and the temperature of hot water in the hot water storage tank 32 is, for example, about 50-65 ° C.

  When a predetermined time elapses, a predetermined amount of heat is stored in the heat storage material 100 and a predetermined amount of hot water is stored in the hot water storage tank 32. For example, the end of the first heat storage mode is determined based on the time, the processing time, the temperature of the first and second heat storage tanks 34 and 36, and / or the amount of stored water in the hot water storage tank 32, and the like.

<Second heat storage mode>
Next, in the second heat storage mode, the heat pump 20 of the hot water supply system 10 is operated using, for example, night power (midnight power). In the second heat storage mode, the valve 71 of the heat pump 20 guides the working fluid from the first compression unit 22A to the second compression unit 22B. The temperature of the working fluid rises by two-stage compression at the first and second compression portions 22A and 22B (m1 + m2 in FIG. 4). The temperature of the working fluid is, for example, about 105 ° C. The valve 73 guides the working fluid from the second compression part 22B to the first heat radiating part 23A. As shown to (e) of FIG. 4, in the 1st heat exchanger 61, the water from the supply source 15 which flows through the 1st heating conduit | pipe 51A of the path | route 51 is heated by the transmitted heat from the 2nd thermal radiation part 23B. Further, as shown in FIG. 4 (d), in the second heat exchanger 63, water (hot water) from the first heating conduit 51A flowing through the second heating conduit 51B of the path 51 flows from the first heat radiating portion 23A. Heated by transfer heat. The temperature of water (hot water) from the second heat exchanger 63 is, for example, about 95 ° C.

  In the second heat storage mode, hot water from the second heat exchanger 63 is introduced into the second heat storage tank 36 via the valve 43 and the path 55. Further, hot water from the second heat exchanger 63 is introduced into the first heat storage tank 34 via the valve 44 and the path 56. That is, in the first and second heat storage tanks 34 and 36, in addition to the latent heat of the heat storage material 100, the sensible heat of the hot water from the second heat exchanger 63 is stored. The temperature of the heat storage material 100 may be further increased by the hot water supplied to the tanks 34 and 36. The temperature of the hot water in the heat storage tanks 34 and 36 is, for example, about 80 to 95 ° C.

  When a predetermined time has elapsed, a predetermined amount of hot water is stored in the first and second heat storage tanks 34 and 36. For example, the end of the second heat storage mode is determined based on the time, the processing time, and / or the amount of water stored in the first and second heat storage tanks 34 and 36.

<First hot water supply mode>
In the first hot water supply mode, hot water from the hot water storage tank 32 and / or the first and second heat storage tanks 34 and 36 is introduced into the water distribution unit 95 in accordance with the hot water demand by controlling valves and pumps. The warm water is supplied from the water distribution unit 95 to various facilities such as a bath, a kitchen, and a washroom. The hot water may be supplied to a manufacturing plant, a cooking facility, an air conditioning facility, a power plant, and the like. As described above, the temperature of the hot water in the hot water storage tank 32 is, for example, about 50 to 65 ° C., and the temperature of the hot water in the heat storage tanks 34 and 36 is, for example, about 80 to 95 ° C. By appropriately combining both hot waters, the supply hot water temperature can be changed within a predetermined range. In the first hot water supply mode, the heat pump 20 is normally in a non-operating state. This mode is preferably used at the start of hot water supply. In this mode, the time required for hot water supply from the instruction is relatively short, and hot water can be continuously supplied within the range of the hot water storage capacity of the heat storage tanks 34 and 36.

<Second hot water supply mode>
In the second hot water supply mode, water from the supply source 15 is introduced into the first and second heat storage tanks 34 and 36 via the path 52 in accordance with hot water demand by controlling valves and pumps. As shown in FIG. 5, the temperature of the water heated by the heat storage material 100 rises. Hot water from the first and second heat storage tanks 34 and 36 is supplied to facilities such as a bath, a kitchen, and a washroom through a water distribution unit 95. Even in the second hot water supply mode, the heat pump 20 is normally in a non-operating state. This mode has a hot water supply capacity (hot water storage amount) corresponding to the heat storage capacity of the heat storage material 100.

<Third hot water supply mode>
In the third hot water supply mode, the heat pump 20 is operated according to the hot water demand. The valve 71 of the heat pump 20 guides the working fluid from the first compression unit 22A to the second compression unit 22B. The working fluid compressed in two stages by the first and second compression sections 22A and 22B rises in temperature (m1 + m2 in FIG. 4). The temperature of the working fluid is, for example, about 105 ° C. The valve 73 guides the working fluid from the second compression part 22B to the first heat radiating part 23A. As shown to (e) of FIG. 4, in the 1st heat exchanger 61, the water from the supply source 15 which flows through the 1st heating conduit | pipe 51A of the path | route 51 is heated by the transmitted heat from the 2nd thermal radiation part 23B. Further, as shown in FIG. 4 (d), in the second heat exchanger 63, water (hot water) from the first heating conduit 51A flowing through the second heating conduit 51B of the path 51 flows from the first heat radiating portion 23A. Heated by transfer heat. The temperature of water (hot water) from the second heat exchanger 63 is, for example, about 95 ° C. Hot water from the second heat exchanger 63 is supplied to facilities such as a bath, a kitchen, and a washroom through a water distribution unit 95. This mode is assisted when the heat storage by the hot water storage tank 32, the first heat storage tank 34, and the second heat storage tank 36 cannot meet the demand for hot water, for example, the amount of heat stored in the heat storage tanks 34, 36 falls below a predetermined amount. Used.

  Thus, in this embodiment, the hot water supply system 10 operates the heat pump 20 at night when the electricity rate is low, and supplies hot water to the outside according to demand. In the heat storage mode, heat is stored in the hot water storage tank 32, the first heat storage tank 34, and the second heat storage tank 36. In addition, storing at least one hot water in the tanks 32, 34, and 36 is advantageous for shortening the rising time of hot water supply.

  In this embodiment, since at least a part of the function of the conventional hot water storage tank is supplemented by the heat storage tanks 34 and 36 having the latent heat storage material 100 having a high stored energy density, the entire apparatus can be made compact.

  Heat storage using the heat storage material 100 (latent heat storage material) having a high heat capacity (accumulated energy density) is advantageous in reducing the heat storage space. Here, the case where sodium acetate trihydrate is used as the heat storage material 100 is considered. Sodium acetate trihydrate has a heat capacity of about 255 kJ / kg (heat of fusion), a specific gravity of about 1.3, and a heat storage temperature of about 58 ° C. On the other hand, the heat capacity of water is 251 kJ / kg (30 to 90 ° C.) and the specific gravity is 1.0. That is, sodium acetate trihydrate has substantially the same heat capacity and a specific gravity 1.3 times that of water. This indicates that the space efficiency of heat storage using sodium acetate trihydrate is 30% higher than that of water.

  When the heat storage temperature of the heat storage material 100 is relatively low (heat storage temperature of sodium acetate trihydrate: 58 ° C.), the temperature of the working fluid introduced from the first heat storage tank 34 to the second compression unit 22B in the first heat storage mode. Is kept relatively low. This is advantageous in improving the compression efficiency of the second compression unit 22B and improving the performance of the heat pump 20.

  Further, in the first heat storage mode, the working fluid from the first and second compression units 22 </ b> A and 22 </ b> B only needs to have a relatively low temperature that can melt the heat storage material 100. This is advantageous for improving COP.

  In the present embodiment, the heat storage tanks 34 and 36 store latent heat from the heat storage material 100 and sensible heat from hot water. By storing the heat storage material 100 and the hot water in the tanks 34 and 36, the temperature of the heat storage material 100 is maintained at a predetermined value or more by the heat of the hot water, and as a result, solidification of the heat storage material 100 is prevented. This is advantageous for stable use of heat of the heat storage material 100.

  Moreover, in this embodiment, the heat storage material 100 is accommodated in the some container 102 by the heat storage tanks 34 and 36, Therefore, the whole heat storage material 100 in the tanks 34 and 36 changes a phase comparatively uniformly. Spaces other than the plurality of containers 102 in the heat storage tanks 34 and 36 can be filled with hot water for sensible heat storage, which is advantageous for improving space utilization efficiency and reducing the size of the system.

  In the present embodiment, in the second heat storage mode, the hot water heated by the first and second heat exchangers 61 and 63 has a relatively high temperature. The fact that the hot water for sensible heat storage has a relatively high temperature (a large amount of heat) is advantageous for efficient use of space.

  In this embodiment, the heating temperature of water is close to the actual use temperature on the demand side, which leads to the suppression of the temperature level of the entire system. The low temperature level of the system is advantageous for reducing the equipment cost and heat loss and improving the COP of the system.

  The heat storage by the latent heat storage material 100 is advantageous for suppressing the initial cost as compared with the heat storage using a battery, and the heat storage efficiency equal to or higher than that can be expected. As a modification of the present embodiment, a battery can be used in a power complementary manner. For example, the energy stored in the battery can be used for heating water at the start of hot water supply.

  In the present embodiment, a part of the working fluid bypasses the first heat exchanger 61 via the bypass path 27, so that the flow rate of the working fluid entering the first heat exchanger 61 is optimized. This is advantageous in effectively using the retained heat of the working fluid. The amount of bypass of the working fluid is determined according to each physical property value (such as specific heat) of water and the working fluid.

  The working fluid flowing through the bypass path 27 exchanges heat with the working fluid from the heat absorbing section 21 flowing through the main path 25 of the heat pump 20 in the regenerator 28. By this heat exchange, the temperature of the working fluid in the bypass path 27 is lowered, and the temperature of the working fluid in the main path 25 of the heat pump 20 is raised. Due to the increase in the input temperature of the working fluid to the compression unit 22, the power of the compression unit 22 is reduced.

  In the present embodiment, the working fluid in the bypass passage 27 whose temperature has dropped in the regenerator 28 is the first heat exchanger 61 (second heat radiating portion 23B) flowing in the main passage 25 of the heat pump 20 before the expansion portion 24. ) And the working fluid from Due to the effect of the flow rate optimization described above, the output temperature of the working fluid from the first heat exchanger 61 is also sufficiently low. Therefore, a working fluid having a relatively low temperature is introduced into the expansion portion 24. The decrease in the input temperature of the working fluid to the expansion section 24 is advantageous for optimizing the liquid gas ratio of the working fluid. As a result, the heat absorption unit 21 effectively absorbs heat from a heat source (atmosphere) outside the cycle. As described above, in the present embodiment, the working fluid after being used for heating the heat storage material 100 is used for warming water and regenerating the working fluid, thereby effectively using heat.

  The numerical value used in the above description is an example, and the present invention is not limited to this.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment. The numerical value used in the above description is an example, and the present invention is not limited to this. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit of the present invention. The present invention is not limited by the above description, but only by the appended claims.

It is the schematic which shows 1st Embodiment. It is a schematic cross section which shows an example of the container of a thermal storage material. It is a schematic cross section which shows another example of the container of a thermal storage material. It is a figure which shows typically the temperature change of the working fluid of a heat pump in 1st thermal storage mode. It is a figure which shows typically the temperature change of the working fluid of a heat pump in the 2nd thermal storage mode and the 3rd hot water supply mode. It is a figure which shows typically the temperature change of the water in 2nd hot-water supply mode.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 12 ... Heat pump unit (1st unit), 15 ... Supply source, 20 ... Heat pump, 21 ... Endothermic part, 22 ... Compression part, 22A ... First compression part, 22B ... Second compression part, 23A ... First heat radiation part, 23B ... 2nd heat radiation part, 24 ... expansion part, 25 ... main path, 27 ... bypass path, 28 ... regenerator, 30 ... supply unit (second unit), 32 ... hot water storage tank, 34 ... first heat storage tank, 36 ... 2nd heat storage tank, 51A ... 1st heating conduit, 51B ... 2nd heating conduit, 61 ... 1st heat exchanger, 63 ... 2nd heat exchanger, 70 ... control apparatus, 95 ... Water distribution part, 100 ... Heat storage material 102. Container.

Claims (15)

A first unit having a heat pump through which the first fluid flows;
A second unit having a tank in which a heat storage material is disposed and a second fluid is stored at least temporarily, wherein the second fluid is heated by heat transferred from at least one of the heat storage material and the first fluid; A second unit;
A hot water supply system comprising:   The hot water supply system according to claim 1, wherein the tank has a heat storage tank that stores both latent heat of the heat storage material and sensible heat of the second fluid heated by the heat pump.   The hot water supply system according to claim 1 or 2, wherein the heat storage material is accommodated in a plurality of containers arranged in the tank.   The heat pump includes: a compression unit that compresses the first fluid; a heat dissipating unit that supplies heat of the first fluid from the compression unit to the second fluid toward the tank; and the first fluid from the compression unit. A hot water supply system according to any one of claims 1 to 3, further comprising a valve that guides the heat to the at least one of the heat radiating section and the tank. The tank has first and second tanks,
The heat pump includes first and second compression units that compress the first fluid, and a first valve that selectively guides the first fluid from the first compression unit to the first tank or the second compression unit. A first heat dissipating part that gives heat of the first fluid from the second compressing part to the second fluid toward the second tank, and the second fluid from the second compressing part to the second tank. Or a second valve that selectively leads to the first heat radiation part,
The said supply unit further has the path | route which guide | induces the said 2nd fluid which received the heat | fever from the said 1st thermal radiation part to the said 1st tank and the said 2nd tank, Any one of Claim 1 to 3 characterized by the above-mentioned. Hot water supply system according to crab.   The heat pump is configured to receive heat from the first heat radiating portion from the first fluid to the second fluid that travels toward the first heat radiating portion, and to receive the heat from the second heat radiating portion. The hot water supply system according to claim 5, further comprising a third tank in which at least a part of the two fluids is stored at least temporarily.   The heat pump includes a bypass path in which a part of the first fluid from the first heat radiating part bypasses the second heat radiating part, and heat from the first fluid in the bypass path is generated by the first compression part. The hot water supply system according to claim 5, further comprising a regenerator that is transmitted to the first fluid upstream.   The hot water supply system according to any one of claims 1 to 7, further comprising a control device that controls an operating state of the heat pump according to a time zone.   The hot water supply system according to any one of claims 1 to 8, wherein the heat storage material is a latent heat storage material. A hot water supply method using a heat pump and a heat storage material,
Storing heat from the heat pump in the heat storage material disposed in the tank;
Storing the first hot water heated by the heat pump in the tank;
Supplying the first hot water stored in the tank to a predetermined facility;
Supplying the second hot water heated by the heat storage material in the tank to the predetermined facility;
Supplying a third hot water heated by the heat pump directly to the predetermined facility.   The hot water supply method according to claim 10, wherein the step of storing the first hot water in the tank is performed after the heat storage to the heat storage material.   The hot water supply method according to claim 10 or 11, wherein an operating state of the heat pump is controlled according to a time zone.   The hot water supply method according to any one of claims 10 to 12, wherein the heat storage material is accommodated in a plurality of containers disposed in the tank.   The hot water supply method according to claim 10, wherein the heat storage material is a latent heat storage material.   The hot water supply method according to any one of claims 10 to 14, further comprising a step of storing the fourth hot water heated by the heat pump in another tank not having the heat storage material.

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