Heat source supply device and method for heat pump using a rainwater tank

Abstract

The present invention relates to a heat source supply device and method for a heat pump using a rainwater tank, wherein the effluent from a sump that stores and discharges effluent groundwater is stored in a rainwater tank during the winter and used as a heat source for a heat pump, thereby reducing the cost of effluent discharge and facilitating the supply of a heat source for a heat pump. The device comprises: a plurality of sumps that collect effluent groundwater and discharge it as effluent; a rainwater tank that collects the effluent discharged from the plurality of sumps only during a specific period and supplies it as a heat source for heat exchange of a circulating medium; a heat exchanger that heat-exchanges the circulating medium with the heat supplied through the rainwater tank; a heat pump that performs a heat storage or cooling storage operation to supply circulating water for cooling or heating to the cooling or heating unit, and is connected to the heat exchanger and a cooling / heating unit through a circulation line through which the circulating medium flows to form a closed loop, and a control unit that controls the operation of the rainwater tank, the heat exchanger, and the heat pump.

Description

Technology Field

[0001] The present invention relates to a heat source supply for a heat pump using a rainwater tank, and more specifically, to a heat source supply device and method for a heat pump using a rainwater tank in which the effluent from a sump that stores and discharges groundwater to the outside is stored in the rainwater tank during the winter and used as a heat source for the heat pump, thereby reducing the cost of effluent discharge and facilitating the supply of a heat source for the heat pump. Background Technology

[0002] In order to prevent flooding caused by groundwater runoff, sumps, which are collection structures that collect runoff groundwater and channel it into the sewer system, are installed in buildings such as apartments, airports, hospitals, and schools, as well as roads and other structures of a certain size or larger.

[0003] A sump stores runoff groundwater and discharges the stored runoff groundwater outside the building using a drainage pump. However, there is a disadvantage in that there are high discharge costs, such as electricity consumption, due to the use of a drainage pump to discharge the collected runoff groundwater outside the building.

[0004] In addition, a rainwater tank has been installed to store summer rainwater, but it is practically neglected during the winter as it is not utilized.

[0005] Meanwhile, energy sources used for heating and cooling primarily consist of fossil fuels such as coal, oil, and natural gas, or electricity generated using these fossil fuels or nuclear power. However, since fossil fuels have the disadvantage of polluting water and the environment due to various pollutants generated during combustion, the development of alternative energy sources to replace them has been actively underway in recent years. Among these alternative energies, research on wind, solar, and geothermal energy—which possess infinite energy resources—and the use of heating and cooling devices utilizing them are being conducted. While these energy sources have the advantage of generating energy with minimal impact on air pollution and climate change, they suffer from the disadvantage of having extremely low energy density.

[0006] With the depletion of fossil fuels and the emergence of environmental pollution issues, research and development for the utilization of clean energy—specifically natural energies such as solar, geothermal, and wind power—are actively underway, and in practice, the use of heat pump cooling and heating systems utilizing solar and geothermal energy is increasing.

[0007] A cooling and heating system utilizing a heat pump, which uses the exothermic or condensation heat of a refrigerant to transfer heat from a low-temperature source to a high temperature or from a high-temperature source to a low temperature, has the advantage of being able to perform both cooling and heating with a single system.

[0008] A heat pump consists of an evaporator, a compressor, a condenser, and an expansion valve.

[0009] In heating mode, the refrigerant, compressed to a high temperature and high pressure by the compressor, is liquefied in the condenser while releasing heat; this heat is utilized for heating and hot water supply, and the system operates by depressurizing the refrigerant to a low temperature and low pressure liquid state via the expansion valve before flowing into the evaporator.

[0010] In cooling mode, the refrigerant absorbs heat and evaporates in the evaporator; cooling is achieved by utilizing the heat absorption of the evaporator, and the operation proceeds in a manner where the evaporated refrigerant flows back into the compressor.

[0011] Due to these advantages, there is an increasing number of cases where cooling and heating systems using heat pumps are installed in places requiring cooling and heating; however, such heat pumps also require a heat source supply, and their efficiency is determined by the temperature and ease of supply of the heat source, as well as the characteristics of the heat source.

[0012] Therefore, technology is required to reduce discharge costs associated with operating drainage pumps to drain effluent stored in sumps during the winter, to enable the utilization of rainwater tanks left neglected during the winter, to facilitate the supply of heat sources for heat pumps, and to reduce energy consumption for heating and cooling. Prior art literature

[0013] Republic of Korea Registered Patent 10-0978800 (Registered Aug. 24, 2010) (Auxiliary heat source supply device for a heat pump system and control method thereof) Republic of Korea Registered Patent 10-1027164 (Registered Mar. 29, 2011) (Hot water and cooling / heating supply system) Republic of Korea Registered Patent 10-2411637 (Registered June 16, 2022) (Geothermal heat pump system including a water collection structure) Republic of Korea Registered Patent 10-2436338 (Registered Aug. 22, 2022) (Filter unit for a geothermal heat pump system using groundwater) The problem to be solved

[0014] Accordingly, the present invention is proposed to solve the problem of the cost of effluent discharge in a sump system that stores general effluent and discharges it outside the building as described above, the problem of leaving the rainwater tank unattended during the winter, and the problem of the cost of constructing a separate facility for supplying heat source to a heat pump, as well as the problem of energy consumption. The purpose of the invention is to provide a heat source supply device and method for a heat pump using a rainwater tank, wherein the effluent from a sump that stores groundwater and discharges it to the outside is stored in the rainwater tank during the winter and used as a heat source for the heat pump.

[0015] Another objective of the present invention is to provide a heat source supply device and method for a heat pump using a rainwater tank, which can reduce the cost of effluent discharge by storing effluent groundwater and discharging it outside the building.

[0016] Another objective of the present invention is to provide a heat source supply device and method for a heat pump using a rainwater tank, which facilitates the supply of a heat source to the heat pump and reduces energy consumption associated with heating and cooling of buildings, etc. means of solving the problem

[0017] In order to achieve the above-mentioned purpose, the "heat source supply device for a heat pump using a rainwater tank" according to the present invention is,

[0018] Multiple collection wells that collect runoff groundwater and discharge it as runoff;

[0019] A rainwater tank that collects effluent discharged from the aforementioned plurality of sumps only during a specific period and supplies it as a heat source for heat exchange of a circulating medium;

[0020] A heat exchanger that heat exchanges a circulating medium with a heat source supplied through the above-mentioned rainwater tank;

[0021] A heat pump that forms a closed loop by being connected to the above-mentioned heat exchanger and cooling / heating unit through a circulation line through which a circulating medium flows, and performs a heat storage or cooling storage operation to supply circulating water for cooling or heating to the above-mentioned cooling / heating unit;

[0022] It is characterized by including a control unit that controls the operation of the above-mentioned excellent tank, heat exchanger, and heat pump.

[0023] Preferably, a water treatment device for removing foreign substances from the heat source supplied from the rainwater tank to the heat exchanger is provided between the heat exchanger and the rainwater tank.

[0024] Preferably, the plurality of sumps are equipped with a drainage pump for discharging collected groundwater runoff, and the drainage pump is characterized by reducing power consumption for discharging groundwater runoff outside the building and for discharging groundwater runoff into a supply pipe connected to a rainwater tank.

[0025] Preferably, the control unit is,

[0026] It is characterized by controlling the effluent inlet valve of the rainwater tank so that the effluent discharged from the plurality of sumps is stored in the rainwater tank only during the winter.

[0027] In addition, the "method for supplying a heat source of a heat pump using a rainwater tank" according to the present invention is,

[0028] (a) A step of setting a season to use the effluent discharged from the sump as a heat source for the heat pump;

[0029] (b) a step of comparing the season set in step (a) above with the current season, and if the current season is not winter, closing the effluent inlet valve for supplying effluent discharged from the sump;

[0030] (c) a step of comparing the season set in step (a) above with the current season, and if the current season is winter, opening the effluent inlet valve to receive the effluent discharged from the sump and storing the effluent discharged from the sump in a rainwater tank;

[0031] (d) a step of controlling the heat source supply device in a heating mode when the effluent stored in the above-mentioned rainwater tank is above a set level;

[0032] (e) The method is characterized by including the step of performing heating by supplying heating heat generated using effluent to a heating and cooling unit while in the state of switching to the heating mode.

[0033] Preferably, the above step (d) is,

[0034] It is characterized by controlling the heat exchanger and heat pump in a heating mode, and controlling the heat dissipation pump / circulation pump / waste heat pump in an open state. Effects of the invention

[0035] According to the present invention, by storing the effluent from a collection well that collects and discharges groundwater to the outside in a rainwater tank during the winter and using it as a heat source for a heat pump, there is an advantage in reducing the energy consumption for heating and cooling.

[0036] In addition, according to the present invention, there is also the advantage of reducing the cost of effluent discharge by collecting the effluent groundwater and discharging it outside the building.

[0037] In addition, according to the present invention, by supplying the effluent collected in the rainwater tank as a heat source for the heat pump, there is also an effect of facilitating the supply of heat source to the heat pump. Brief explanation of the drawing

[0038] FIG. 1 is an example of using the effluent from a collection well that collects groundwater in the present invention as a heat source for a heat pump by storing it in a rainwater tank. FIG. 2 is a configuration diagram of a heat source supply device for a heat pump using a rainwater tank according to the present invention, and FIG. 3 is a flowchart showing a method for supplying a heat source to a heat pump using a rainwater tank according to the present invention. Specific details for implementing the invention

[0039] Hereinafter, a heat source supply device and method for a heat pump using a rainwater tank according to a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0040] The terms or words used in the present invention described below should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0041] Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely preferred embodiments of the present invention and do not represent all technical concepts of the present invention; thus, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0042] FIG. 1 is an example of a heat source supply device for a heat pump using a rainwater tank according to a preferred embodiment of the present invention, in which runoff groundwater collected in a sump is stored in the rainwater tank for a specific period and used as a heat source for the heat pump.

[0043] In the basement of the building, etc., there are multiple collection wells (11, 12, 13 ~ N) for collecting outflowing groundwater, and each collection well is equipped with a drainage pump for discharging the collected outflowing groundwater outside the building.

[0044] Since the configuration and operation of each sump are identical, for the convenience of the following explanation, we will describe only one sump (e.g., 11).

[0045] In the summer, the runoff groundwater collected in the sump (11) is discharged outside the building using a drainage pump (11a), and in the winter, the collected runoff groundwater is stored in the rainwater tank (1) through the runoff water supply pipe (2).

[0046] Here, the rainwater tank (1) is generally used to store rainwater during the summer and is not utilized during the winter, prior to collecting runoff water. However, in the present invention, the rainwater tank (1) that is not utilized during the winter is utilized to collect and store runoff water discharged from the collection well (11).

[0047] Although not shown in the drawing, the rainwater tank (1) is equipped with an effluent inlet valve. In the summer, the effluent inlet valve is closed to prevent the effluent discharged from the sump (11) from entering the rainwater tank (1), and in the winter, the effluent inlet valve is opened to collect the effluent discharged from the sump (11) in the rainwater tank (1).

[0048] This effluent inlet valve can be implemented as an electronic valve, and opening and closing control can be performed through automatic control by the control unit (30) described later.

[0049] In addition, the rainwater tank (1) is equipped with a water level sensor that measures the water level of the collected effluent, although this is not indicated in the drawing. The water level detection value of this water level sensor is provided to the control unit (30) in real time so that the control unit (30) can use the effluent as a heat source for the heat pump without any hindrance.

[0050] In the present invention, the rainwater tank (1) is described as being utilized only during the winter to serve as a heat source for heating energy, but it is not limited to this. Depending on the needs, it is also possible to store runoff water in the rainwater tank (1) at all times to serve as a heat source for cooling, or to supply it as water for use in the building's restrooms, etc., through water treatment.

[0051] FIG. 2 is a configuration diagram of a “heat source supply device for a heat pump using a rainwater tank” according to the present invention, and may include a rainwater tank (1), a heat pump (10), a heat exchanger (20), a control unit (30), a water treatment device (40), a heating and cooling unit (100), a heat dissipation pump (200), a circulation pump (300), a waste heat pump (400), etc.

[0052] The rainwater tank (1) collects the effluent from multiple collection wells (11, 12, 13 ~ N) that collect the effluent and discharge it as effluent, and then collects the effluent for a specific period and supplies it as a heat source for heat exchange of the circulation medium.

[0053] The water treatment device (40) is placed between the heat exchanger (20) and the rainwater tank (1) and serves to remove foreign substances (e.g., soil) from the heat source supplied from the rainwater tank (1) to the heat exchanger (20) using a filter.

[0054] The treated heat source is supplied to the heat exchanger (20) through the circulation line (L5), and a waste heat pump (400) is installed in the circulation line (L5) to efficiently supply the effluent to the heat exchanger (20), and the waste heat pump (400) performs a pumping operation under the control of the control unit (30).

[0055] The heat exchanger (20) serves to heat exchange a circulating medium with a heat source supplied through the rainwater tank (1). This heat exchanger (20) is connected to the heat pump (10) through supply and return circulation lines (L3, L4) that form a closed loop while a circulating medium (e.g., hot water or cold water) flows through it to enable the heat storage or cooling operation of the heat pump (10), and heat exchanges the circulating medium according to the seasonal operation mode.

[0056] Here, a circulation pump (300) is formed in the circulation line (L3) to rapidly supply the circulation medium, which is heat-exchanged by the heat exchanger (20), to the heat pump (10), and the pumping operation of the circulation pump (300) is performed under the control of the control unit (30).

[0057] The heat pump (10) is connected to the cooling and heating unit (100) via a circulation line (L1, L2) through which a circulation medium flows, forming a closed loop, and performs a heat storage or cooling storage operation to supply circulating water for cooling or heating to the cooling and heating unit (100).

[0058] Here, a heat dissipation pump (200) is formed in the circulation line (L1) to rapidly supply circulating water, which is stored for heat or cold by the heat pump (10), to the cooling and heating unit (100), and the pumping operation of the heat dissipation pump (200) is performed under the control of the control unit (30).

[0059] This heat pump (10) is equipped with an evaporator, a condenser, etc. to enable heat storage or cooling operation.

[0060] The control unit (30) controls the operation of the above-mentioned rainwater tank (1), heat exchanger (20), and heat pump (30), etc.

[0061] This control unit (30) can control the effluent inlet valve of the rainwater tank (1) so that the effluent discharged from the plurality of sumps is stored in the rainwater tank (1) only during the winter.

[0062] FIG. 3 is a flowchart showing a "method for supplying a heat source of a heat pump using a rainwater tank" according to the present invention, wherein a heat source supply device of a heat pump is controlled software-wise by a control unit (30) to ensure smooth supply of a heat source using a rainwater tank, comprising: (a) a step of setting a season to use the effluent discharged from a sump (e.g., 11) as a heat source for the heat pump (10) (S101); (b) a step of comparing the season set in step (a) with the current season, and if the current season is not winter, closing the effluent inlet valve to receive the effluent discharged from the sump (S102 - S103); (c) a step of comparing the season set in step (a) with the current season, and if the current season is winter, opening the effluent inlet valve to receive the effluent discharged from the sump to store the effluent discharged from the sump in the rainwater tank (1) (S102, S104 - S105); and (d) the If the effluent stored in the rainwater tank (1) is above a set level, the method may include the step of controlling the heat source supply device in a heating mode (S107 - S109), and (e) the step of supplying heating heat generated using the effluent to the heating unit (100) to perform heating while in the state of switching to the heating mode (S110 - S111).

[0063] The above step (d) can control the heat exchanger (20) and heat pump (10) in a heating mode and control the heat dissipation pump (200), circulation pump (300), and waste heat pump (400) in an open state.

[0064] The operation of the "heat source supply device and method for a heat pump using a rainwater tank" according to the present invention configured as described above is specifically explained as follows.

[0065] First, in order to control the heat source of the heat source supply device of the heat pump, the season is set using an input device (S101). For example, as a season for heating, the period from November to March can be set as the winter heating season. The input device may be linked with the control unit (30) or formed integrally with the control unit (30), and when the season is set through the input device, the control unit (30) can distinguish the season based on the current date. To this end, the control unit may be equipped with a timer for checking the date or a GPS module capable of obtaining time and date information in real time.

[0066] The control unit (30) stores the season for heating control in internal memory when the season is set, compares the set season (November to March) with the current season (date), and if the current season is not the set winter season, closes the effluent inlet valve to receive the effluent discharged from the sump (10) (S102 - S103).

[0067] In contrast, when comparing the set season with the current season (date), if the current season is the set winter season, the effluent inlet valve for supplying the effluent discharged from the sump (11) is opened to store the effluent discharged from the sump (11) in the rainwater tank (1) (S102, S104 - S105).

[0068] Here, the sump (11) collects and stores the runoff groundwater, and discharges the stored runoff groundwater outside the building using a drainage pump (11a). At this time, the drainage pump (11a) reduces the power consumption for discharge of runoff water during the winter by differentiating the power consumption when discharging the runoff groundwater outside the building and when discharging the runoff groundwater into the supply pipe (2) connected to the rainwater tank (1).

[0069] That is, when collecting and discharging the effluent groundwater outside the building during seasons other than winter, the drainage pump (11a) is operated with the same power as before to discharge the collected effluent groundwater outside the building, and when it is winter, the drainage pump is controlled to discharge the collected effluent groundwater into the supply pipe (2). At this time, assuming that the power to discharge the collected effluent groundwater outside the building is 100, the power to discharge the collected effluent groundwater into the supply pipe (2) is used at 50 or less, thereby reducing the power to discharge the effluent water.

[0070] Meanwhile, the control unit (30) obtains a water level detection value by communicating in real time with a water level sensor installed in the rainwater tank (1) in the winter heating mode, and compares the obtained water level detection value with a reference detection value stored in an internal memory; if the water level detection value is greater than the reference detection value, it closes the outflow water inlet valve to prevent the outflow water stored in the rainwater tank (1) from overflowing.

[0071] In addition, the control unit (30) compares the water level detection value with the heat source reference value for heating, and when the water level detection value is greater than or equal to the heat source reference value, it operates the heat source supply device in a heating mode so that heating is performed using the effluent water as a heat source (S106 ~ S107).

[0072] When the heating mode is operated, the control unit (30) operates the heat exchanger (20) and the heat pump (10) in the heating mode, and simultaneously controls the heat dissipation pump (200), the circulation pump (300), and the waste heat pump (400) to be in an open state (S108 - S109).

[0073] When the heating mode is in operation, the effluent discharged from the rainwater tank (1) is supplied to the heat exchanger (20) after foreign substances are removed through the water treatment device (40).

[0074] Here, a waste heat pump (400) is installed in the circulation line (L5) of the heat source supply, and the waste heat pump (400) pumps under the control of the control unit (30) and pumps the effluent collected in the rainwater tank (1) to the heat exchanger (20).

[0075] At this time, the heat exchanger (20) is connected to the heat pump (10) through another supply and return circulation line (L3)(L4), and the supply and return circulation line (L3)(L4) has a circulation medium for hot water and cold water circulated according to the seasonal operation mode. When the circulation medium passes through the heat exchanger (20) from the pumping operation of the circulation pump (300) controlled by the control unit (30), the circulation medium is heat-exchanged from the heat source of the effluent flowing through the heat exchanger (20) and then circulated to the heat pump (10) including an evaporator and a condenser.

[0076] Then, the evaporator and condenser of the heat pump (10) are controlled by the control unit (30) and their operation is selectively performed in a seasonal operation mode, thereby performing heat storage or cold storage operations from the circulation medium of the hot or cold water where the heat exchange takes place. Accordingly, the circulating water that performs heat storage or cold storage circulates in the supply and return circulation lines (L1) (L2) connecting the heat pump (10) and the cooling / heating unit (100), and thus the cooling / heating unit (100) can perform heating operation in winter and cooling operation in summer.

[0077] For example, when the above-mentioned heating and cooling unit (100) is in heating operation, the circulating medium passing through the heat exchanger (20) is heated while absorbing the heat source of the effluent water, and the heated circulating medium transfers heat to the heat pump (10) along the circulation line (L3) from the pumping operation of the circulating pump (300) controlled by the control unit (30).

[0078] Then, the evaporator in the heat pump (10) vaporizes the low-temperature liquid refrigerant into a low-temperature gas and transfers it to the compressor, and the compressor generates a high-temperature high-pressure gas, and accordingly, the condenser in the heat pump (10) converts the circulating water flowing into the heat pump (10) from the cooling and heating unit (100) along the circulation line (L2) into high-temperature water, and then recirculates it to the cooling and heating unit (100) through another circulation line (L1), thereby making heating by the cooling and heating unit (100) possible (S110 - S111).

[0079] Cooling operation is controlled by controlling the operation of the heat pump in the same way as conventional cooling. Since the core of the present invention is to perform heating by utilizing the effluent (effluent groundwater) stored in the rainwater tank (1) during winter, a detailed explanation of the cooling operation will be omitted.

[0080] According to the present invention described above, the effluent from a collection well that collects and discharges groundwater to the outside is stored in a rainwater tank during the winter, and by using this as a heat source for a heat pump, the energy consumption for heating and cooling can be reduced.

[0081] In addition, according to the present invention, the cost of effluent discharge can be reduced by collecting groundwater runoff during the winter and discharging it outside the building.

[0082] In addition, according to the present invention, by supplying the effluent collected in the rainwater tank as a heat source for the heat pump, it is possible to facilitate the supply of a heat source for the heat pump.

[0083] Although the invention made by the inventors has been specifically described according to the above embodiments, it is obvious to those skilled in the art that the invention is not limited to the above embodiments and can be modified in various ways without departing from the gist thereof. Explanation of the symbols

[0084] 1: Excellent Team 2: Supply pipe 11, 12, 13, N: Catch basin 11a, 12a, 13a, Na: Drainage pump 10: Heat pump 20: Heat exchanger 30: Control unit 40: Water treatment device 100: Heating and cooling unit 200: Heat pump 300: Circulation pump 400: Waste heat pump

Claims

Claim 1 A heat source supply device for a heat pump using a rainwater tank, characterized by comprising: a plurality of collection wells for collecting runoff groundwater and discharging it as runoff; a rainwater tank for collecting runoff discharged from the plurality of collection wells only during a specific period and supplying it as a heat source for heat exchange of a circulating medium; a heat exchanger for heat exchange of a circulating medium using the heat source supplied through the rainwater tank; a heat pump that forms a closed loop by connecting the heat exchanger and the cooling / heating unit to a circulating line through which the circulating medium flows, and performs a heat storage or cooling storage operation to supply circulating water for cooling or heating to the cooling / heating unit; and a control unit for controlling the operation of the rainwater tank, the heat exchanger, and the heat pump. Claim 2 A heat source supply device for a heat pump using a rainwater tank, characterized in that, in claim 1, a water treatment device for removing foreign substances from the heat source supplied from the rainwater tank to the heat exchanger is disposed between the heat exchanger and the rainwater tank. Claim 3 A heat source supply device for a heat pump using a rainwater tank, wherein, in claim 1, the plurality of sumps are equipped with a drainage pump for discharging collected groundwater runoff, and the drainage pump is characterized by having a difference in power consumption when discharging groundwater runoff outside the building and when discharging groundwater runoff into a supply pipe connected to a rainwater tank, thereby reducing power consumption for discharging groundwater runoff during the winter. Claim 4 A heat source supply device for a heat pump using a rainwater tank, wherein, in claim 1, the control unit controls the effluent inlet valve of the rainwater tank to store the effluent discharged from the plurality of sumps in the rainwater tank only during the winter. Claim 5 A method for controlling the heat source supply of a heat pump using a heat source supply device utilizing a rainwater tank as described in any one of claims 1 to 4, comprising: (a) a step of setting a season for using effluent discharged from a sump as a heat source for the heat pump; (b) a step of comparing the season set in step (a) with the current season, and if the current season is not winter, closing an effluent inlet valve for receiving effluent discharged from the sump; (c) a step of comparing the season set in step (a) with the current season, and if the current season is winter, opening an effluent inlet valve for receiving effluent discharged from the sump to store the effluent discharged from the sump in a rainwater tank; (d) a step of controlling the heat source supply device to a heating mode if the effluent stored in the rainwater tank is above a set level; and (e) a step of supplying heating heat generated using the effluent to a cooling and heating unit to perform heating while in a state switched to the heating mode. Claim 6 Claim 1, wherein step (d) is characterized by controlling the heat exchanger and the heat pump to a heating mode during the heating mode, and controlling the heat dissipation pump, the circulation pump, and the waste heat pump to an open state, in a method for supplying a heat source to a heat pump using a rainwater tank.

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