System and method for providing domestic hot water and / or space heating within a building

Abstract

The present invention provides a system and a method for providing domestic hot water and / or space heating in a building. The system can be used in the method, characterized by comprising: a first storage device containing a first phase change material; a first detector for determining a charging state of the first storage device; and a first phase change material heat exchanger adapted to exchange heat between a refrigerant from a refrigeration circuit and the first phase change material. The system further comprises: a second storage device containing a second phase change material; a second detector for determining a charging state of the second storage device; and a second phase change material heat exchanger adapted to exchange heat between the second phase change material and water of a heating medium circuit. A controller is configured to control operation of the system based on at least the charging state of the first storage device and the charging state of the second storage device.

Description

Technical Field

[0001] This invention provides a system and method for providing domestic hot water and / or space heating within a building. The system, which can be used in the method, is characterized by comprising: a first storage device containing a first phase change material; a first detector for determining the thermal charge state of the first storage device; and a first phase change material heat exchanger adapted to exchange heat between a refrigerant from a refrigeration circuit and the first phase change material. The system further comprises: a second storage device containing a second phase change material; a second detector for determining the thermal charge state of the second storage device; and a second phase change material heat exchanger adapted to exchange heat between the second phase change material and water in a heat transfer medium circuit. A controller is configured to control the operation of the system based at least on the thermal charge states of the first and second storage devices. Background Technology

[0002] The main limitation of heat pump heating products for single-family homes compared to small combined boilers (typically 20-30kW) is their low heat transfer rate (typically 5-15kW). This means that heat pumps must typically be equipped with a storage tank for domestic hot water, which can be charged for extended periods when convenient. At a supply temperature of approximately 42°C, a typical shower uses about 7 liters of water per minute: assuming a tap water temperature of 10°C, this results in a heat load of approximately 16kW. A single shower uses approximately 50 liters of water and 6.5 MJ (1.8 kWh) of heat.

[0003] Phase change materials (PCMs) have been proposed as a more compact alternative to traditional water-based thermal storage for domestic heating applications, namely space heating and domestic hot water heating. These two applications have different temperature requirements. For domestic hot water (DHW), the point-of-use temperature is typically in the range of 40-55°C, while for space heating, the temperature range can be higher or lower, depending on the type and size of the heating system. Older district heating systems designed with fossil fuel boilers and traditional radiators can use water flow temperatures in the range of 60-80°C, while modern heating systems designed for electric heat pumps use water flow temperatures in the range of 35-45°C for large radiator areas.

[0004] Meanwhile, heat pumps are designed to operate year-round under various outdoor conditions. A typical mode of heat pump control in space heating operation uses a climate compensation curve, for which the water flow temperature increases as the outdoor ambient temperature decreases. This means that air source heat pumps need to operate under a wide range of "temperature rise" conditions; where "temperature rise" is the difference between the heat source temperature and the output temperature of the heat pump in heating mode. Therefore, when designed for higher peak load conditions in winter, air source heat pumps suffer from partial load inefficiency when the heat source temperature (outdoor air temperature) is very low and the required heat delivery temperature (water flow temperature) is very high. In other words, these heat pump systems have a lower coefficient of performance (COP).

[0005] A construction for improving heat pump efficiency and coefficient of performance is proposed, which divides the heat pumping process into two stages, each with a small temperature rise, and uses the ground surface as a heat storage tank to store heat energy pumped from the air (e.g., <0°C) at an intermediate temperature (e.g., 10°C) until needed, at which point the heat energy can be pumped through the second stage to reach its required delivery temperature (e.g., 40°C for space heating). The problem with this approach is that the cost and inconvenience of installing shallow coil or deep well-type ground heat exchangers are often high, making the method and system very expensive.

[0006] For demand-side flexibility services, there is a greater focus on increasing heat storage for both domestic hot water and space heating. In this regard, many heat pump systems are designed with heat storage units that can compensate for heat pump operating time from space heating demand. The problem with this approach is that, for many single-family homes, the space requirements for both domestic hot water storage tanks and space heating heat storage units (typically water tanks) can be excessive.

[0007] JP2008180473A discloses a system and method in which, when the heat source is insufficient or does not meet the user's needs, the atmosphere is used as a heat source to provide backup heating by operating a heat pump with electricity at night.

[0008] JP2012007796A discloses a system and method in which the thermal storage system includes: a thermal storage tank for storing latent heat storage materials separately; a circulation channel passing through the thermal storage tank in ascending order of the melting points of the latent heat storage materials in the thermal storage tank; a supply path for supplying a heating medium to one end of the circulation channel; and a distribution channel for removing the heating medium from the other end of the circulation channel.

[0009] In summary, existing systems and methods suffer from at least the following drawbacks. First, if a single-stage heat pump system is used, it must operate across a significant temperature difference between the outdoor air heat source and the required delivery temperature of the domestic hot water, making efficient operation, i.e., operation at a high coefficient of performance (COP), impossible. Second, if a two-stage heat pump system or two compressors is used, the system becomes more complex and costly to provide. Third, if a heat storage device, such as a water tank, is used, it occupies a large space, leaving less space in the room for other purposes, especially in indoor rooms. Summary of the Invention

[0010] Therefore, the purpose of this application is to provide a system and method for providing domestic hot water and space heating within a building, which avoids the disadvantages of existing systems and methods. Specifically, the system and method should enable the provision of domestic hot water and / or space heating within a building in a more efficient manner and with the minimum space required for implementation. Preferably, it should also provide a system and method for providing domestic hot water and space heating within a building, and implement the corresponding method at a low cost.

[0011] The objective is achieved by an apparatus having the features of technical solution 1 and a method having the features of technical solution 9. Dependent technical solutions describe advantageous embodiments of the invention.

[0012] According to the present invention, a system for providing domestic hot water and / or space heating in a building is provided, the system comprising:

[0013] a) A refrigeration circuit, the refrigeration circuit comprising:

[0014] As a heat transfer medium, refrigerant

[0015] compressor,

[0016] Expansion valve 1 and expansion valve 2,

[0017] The first three-way valve and the second three-way valve,

[0018] Four-way switching valve

[0019] An outdoor heat exchanger, the outdoor heat exchanger being adapted to perform heat exchange between the refrigerant and air, and

[0020] A first storage device, the first storage device comprising a first phase change material, wherein,

[0021] The first storage device includes a first detector for determining the thermal state of the first storage device, and includes a first phase change material heat exchanger adapted to perform heat exchange between the refrigerant and the first phase change material;

[0022] b) A heat transfer medium circuit, the heat transfer medium circuit comprising:

[0023] Water as a heat medium

[0024] A second storage device, thermally connected to a domestic hot water circuit and comprising a second phase change material, wherein the phase change temperature of the second phase change material is higher than that of the first phase change material, wherein the second storage device includes a second detector for determining the thermal charge state of the second storage device, and includes a second phase change material heat exchanger adapted to facilitate heat exchange between the water in the heat medium circuit and the second phase change material.

[0025] A third three-way valve, adapted to switch water flow to at least one radiator for space heating within a building or to the second phase change material heat exchanger, and

[0026] At least one conveying mechanism for circulating water through a heat medium heat exchanger;

[0027] c) A heat medium heat exchanger, which is configured via the refrigeration circuit and the heat medium circuit, and is adapted to transfer heat between the refrigerant and water; and

[0028] d) A controller configured to control the operation of the system based at least on the thermal state of the first storage device determined by information obtained from the first detector and the thermal state of the second storage device determined by information obtained from the second detector.

[0029] The system's advantage lies in its ability to provide domestic hot water and space heating within buildings more efficiently. Higher efficiency and coefficient of performance are achieved by arranging the first and second storage units, both of which contain phase change materials. These two storage units allow the heat pumping process to be divided into two stages with intermediate storage temperature conditions: a first heat pumping stage between low and intermediate temperatures, and a second heat pumping stage between intermediate and high temperatures. Higher efficiency and coefficient of performance are also achieved by controlling the system based at least on the charge states of the first and second storage units, as the system can reliably select an appropriate operating mode based on the corresponding charge states. For example, if the charge state of the first storage unit is high (e.g., at or above a set lower limit), the controller can select an operating mode in which the heat for heating the space or for charging the second storage unit is directly provided by the first storage unit, rather than directly by outside air (which would be inefficient, especially when the outside air temperature is low). Furthermore, if the heating state of the second storage device is low (e.g., below a set lower limit), the controller can select an operating mode in which heat is only transferred to the second storage device to heat it and enable the second storage device to efficiently provide a large amount of domestic hot water.

[0030] The system also has the advantage of providing domestic hot water and space heating within a building with minimal system space requirements. Because the system uses two storage devices containing phase change material (PCM), and PCM has a relatively high heat storage capacity, the total volume of these two storage devices can be smaller compared to, for example, using a storage tank without PCM (e.g., a conventional domestic hot water tank) to store heat energy. Preferably, the system does not include a storage tank lacking PCM.

[0031] According to the present invention, the thermal state of the storage devices (i.e., the first storage device and the second storage device, respectively) is the amount of thermal energy stored in the storage devices. In other words, the thermal state of the storage devices indicates the amount of thermal energy that the storage devices can provide. The thermal state of the storage devices also refers to the amount of thermal energy required to heat up the storage devices.

[0032] The detectors used to determine the thermal state of the storage devices (i.e., the first and second detectors for determining the thermal state, respectively) may include at least one temperature sensor (optionally more than one temperature sensor) adapted to detect the temperature inside the storage device. The at least one temperature sensor (optionally all temperature sensors) may be adapted (e.g., by placing it on or at the outer surface of the storage device) to detect the temperature of the outer surface of the storage device. The at least one temperature sensor (optionally all temperature sensors) or at least one additional temperature sensor besides the at least one temperature sensor may be adapted (e.g., by placing it within the internal volume of the storage device, such as inside the storage device or inside a phase change material heat exchanger within the storage device) to detect the temperature of the contents inside the storage device. In this respect, the thermal state of the storage device may be determined, for example, as described in European patent application EP21213459.7. Alternatively, the detector used to determine the thermal state may include at least one temperature sensor and at least one resistance sensor (e.g., individual sensors or a combination of temperature-resistance sensors), wherein at least the resistance sensor is adapted (e.g., by being placed within the internal volume of the storage device and by contacting the internal contents) to detect the resistance of the contents (specifically, a fluid comprising PCM or composed thereof) inside the storage device. In this respect, the thermal state of the storage device can be determined, for example, as described in European patent application EP21166193.9.

[0033] The conveying mechanism used to circulate water through a heat exchanger can be a pump.

[0034] In a preferred embodiment, the system according to the invention does not include a two-stage compressor and / or does not include another (i.e., at least a second) compressor. Lower complexity is achieved by using only a single compressor to pump heat in both the first and second stages, and the system can be provided at a lower cost. Furthermore, since heat can be pumped in both stages with a smaller temperature difference using the same single compressor, a smaller temperature rise and a higher coefficient of performance are achieved through the heat pump.

[0035] In another preferred embodiment, the first storage device is located outdoors, preferably within the outdoor unit of the heat pump, which includes the compressor, the first expansion valve, the second expansion valve, the first three-way valve, the second three-way valve, the four-way switching valve, the outdoor heat exchanger, and the heat transfer medium heat exchanger. The advantages of this embodiment are that the system requires only minimal space within a building's interior rooms, and the system can operate more efficiently. Furthermore, the outdoor location of the first storage device is not associated with higher heat loss because the first storage device contains a phase change material with a phase change temperature lower than that of the second storage device. Therefore, the temperature inside the first storage device can be kept lower, resulting in a lower temperature gradient to the outdoor environment compared to when the second storage device is located outdoors.

[0036] Therefore, in another preferred embodiment, the second storage device (containing a phase change material with a higher phase change temperature) is preferably located indoors (i.e., inside a building). Since a large portion of the required total heat storage can be provided by the low-temperature phase change material in the first storage device, the size of the second storage device can be smaller than that of the first storage device, which provides more free space in the room where the second storage device is located. This is particularly relevant if the room is inside a building.

[0037] The first phase change material may have a phase change temperature that is an intermediate value between the winter outdoor ambient air temperature at the location of the system and the phase change temperature of the second phase change material. For example, the phase change temperature of the first phase change material may be in the range of 10°C to 35°C, preferably in the range of 20°C to 30°C.

[0038] The phase transition temperature of the second phase change material can be in the range of 35°C to 60°C, preferably in the range of 40°C to 50°C.

[0039] The controller can be configured to control the operation of the system, which is further based on the defrosting operation requirements (of the outdoor heat exchanger). For this purpose, the outdoor heat exchanger may include a temperature sensor adapted to communicate with the controller, or the system may include a temperature sensor adapted to communicate with the controller for detecting the refrigerant temperature. In this embodiment, the outdoor heat exchanger may include an outdoor heat exchanger temperature sensor, and the controller may be configured to select a defrosting operation mode based on temperature information transmitted by the temperature sensor. The advantage of this configuration is that the controller can switch to a defrosting operation mode when defrosting operation is required. In the defrosting operation mode, the outdoor heat exchanger can be defrosted, allowing the outdoor heat exchanger to operate more efficiently after the defrosting operation.

[0040] The controller can be configured to control the operation of the system, which is further based on the heating needs of the space within the building. In this embodiment, the system may include an indoor air temperature sensor in the indoor space to be heated, and the controller may be configured to select a space heating operation mode based on temperature information transmitted by the temperature sensor. The advantage of this controller configuration is that if there is a space heating demand, the system can switch to a single-space heating operation mode. For example, in this heating mode, no heating energy is used to heat the first storage unit and / or the second storage unit and / or to provide domestic hot water. This is advantageous because heating the space to be heated becomes more efficient. If there is no space heating demand, the system can switch to an operation mode that does not use heat to provide space heating. For example, in this operation mode, heat is used to heat the first storage unit and / or the second storage unit and / or to provide domestic hot water. This is advantageous because heating domestic hot water and / or heating the first storage unit and / or the second storage unit becomes more efficient.

[0041] The controller can be configured to control the operation of the system, which is further based on the outdoor ambient air temperature. In this embodiment, the system may include an outdoor air temperature sensor in the outdoor space, and the controller can be configured to select the operating mode of the system based on the temperature information transmitted by the temperature sensor. The advantage of this controller configuration is that the outdoor ambient air temperature can be used to determine whether to heat the second storage device using heat from the outdoor air (if the outdoor ambient air temperature is at or above a set lower limit) or to heat the second storage device using heat from the first storage device (if the outdoor ambient air temperature is below the set lower limit). This allows for more efficient heating of the second storage device because heat is pumped into the second storage device through a shallower temperature gradient. Furthermore, the outdoor air temperature can be used to determine whether to use heat from the outdoor air for space heating (if the outdoor ambient air temperature is at or above a set lower limit) or to use heat from the first storage device for space heating (if the outdoor ambient air temperature is below the set lower limit). This allows for more efficient space heating because heat is pumped into the space to be heated through a shallower temperature gradient.

[0042] The first three-way valve is preferably located in the fluid line connecting the compressor to the first phase change material heat exchanger and the heat medium heat exchanger.

[0043] Furthermore, the second three-way valve is preferably located in the fluid line connecting the compressor to the first phase change material heat exchanger and the outdoor heat exchanger.

[0044] The refrigeration circuit of the system may include a receiving device (liquid reservoir). The receiving device may be located in the fluid line between the first expansion valve and the second expansion valve in the refrigeration circuit.

[0045] The first expansion valve of the refrigeration circuit of the system can be located in the fluid line between the outdoor heat exchanger and the receiving device of the refrigeration circuit.

[0046] The second expansion valve of the refrigeration circuit may be located in the fluid line between the receiving device of the refrigeration circuit and the fluid line branching to the first phase change material heat exchanger and the heat medium heat exchanger.

[0047] The controller of the system can be configured as follows:

[0048] If defrosting of the outdoor heat exchanger is required,

[0049] This allows heat from the first phase change material heat exchanger to be transferred to the outdoor heat exchanger.

[0050] The controller is preferably configured as follows:

[0051] i) Set the four-way switching valve to a position that allows refrigerant to flow from the first phase change material heat exchanger via the compressor to the outdoor heat exchanger;

[0052] ii) Configure the first three-way valve to direct refrigerant from the first phase change material heat exchanger to the compressor;

[0053] iii) Set the second three-way valve to direct refrigerant from the compressor to the outdoor heat exchanger; and

[0054] The orifice of the first expansion valve and the orifice of the second expansion valve are adjusted together to control evaporator overheating and compressor undercooling.

[0055] The advantage of this controller design is that the heat stored in the second storage device can be used to defrost the outdoor heat exchanger in colder environments without compromising the comfort of the interior living space or the supply temperature of domestic hot water.

[0056] The controller of the system can be configured as follows:

[0057] If defrosting of the outdoor heat exchanger is not required

[0058] If the determined heating state of the second storage device is lower than the set lower limit, and

[0059] If the determined heating state of the first storage device is lower than a set lower limit, or if the determined outdoor air temperature is at or above a set lower limit for the outdoor ambient air temperature,

[0060] This allows heat from the outdoor heat exchanger to be transferred to the heat medium heat exchanger, especially before the determined charging state of the second storage device is at or above a set upper limit.

[0061] The controller is preferably configured such that, especially before the determined heating state of the second storage device is at or above a set upper limit,

[0062] i) Set the four-way switching valve to a position that allows refrigerant to flow from the outdoor heat exchanger through the compressor to the heat medium heat exchanger;

[0063] ii) Set the first three-way valve to direct refrigerant from the compressor to the heat medium heat exchanger;

[0064] iii) Set the second three-way valve to direct refrigerant from the outdoor heat exchanger to the compressor;

[0065] iv) Jointly adjust the orifice of the first expansion valve and the orifice of the second expansion valve to control evaporator overheating and compressor undercooling; and

[0066] v) Set the third three-way valve to direct water to the second phase change material heat exchanger.

[0067] The advantage of this controller design is that the second storage device can be heated using thermal energy from the outside air.

[0068] The controller can be configured as follows:

[0069] If defrosting of the outdoor heat exchanger is not required

[0070] If the determined heating state of the second storage device is lower than the set lower limit, and

[0071] If the determined heating state of the first storage device is at or above a set lower limit, and if the determined outdoor air temperature is below a set lower limit for the outdoor ambient air temperature,

[0072] This allows heat from the first phase change material heat exchanger to be transferred to the heat medium heat exchanger, especially before the determined charging state of the second storage device is at or above a set upper limit.

[0073] The controller is preferably configured such that, especially before the determined heating state of the second storage device is at or above a set upper limit,

[0074] i) Set the four-way switching valve to a position that allows refrigerant to flow from the first phase change material heat exchanger via the compressor to the heat medium heat exchanger;

[0075] ii) Set the first three-way valve to direct refrigerant from the compressor to the heat medium heat exchanger;

[0076] iii) Set the second three-way valve to guide the refrigerant from the first phase change material heat exchanger to the compressor;

[0077] iv) Jointly adjust the orifice of the first expansion valve and the orifice of the second expansion valve to control evaporator overheating and compressor undercooling; and

[0078] v) Set the third three-way valve to direct water to the second phase change material heat exchanger.

[0079] The advantage of this controller configuration is that the second storage device can be heated using thermal energy from the first storage device.

[0080] The controller can be configured as follows:

[0081] If defrosting of the outdoor heat exchanger is not required

[0082] If the determined heating state of the second storage device is at or above a set lower limit...

[0083] If there is a need for heating within the building, and

[0084] If the determined heating state of the first storage device is below a set lower limit, or if the determined outdoor air temperature is at or above a set lower limit of the outdoor ambient air temperature, then heat from the outdoor heat exchanger is allowed to be transferred to the heat medium heat exchanger, wherein the controller is preferably configured as follows:

[0085] i) Set the four-way switching valve to a position that allows refrigerant to flow from the outdoor heat exchanger through the compressor to the heat medium heat exchanger;

[0086] ii) Set the first three-way valve to direct refrigerant from the compressor to the heat medium heat exchanger;

[0087] iii) Set the second three-way valve to direct refrigerant from the outdoor heat exchanger to the compressor;

[0088] iv) Jointly adjust the orifice of the first expansion valve and the orifice of the second expansion valve to control evaporator overheating and compressor undercooling; and

[0089] v) Configure the third three-way valve to direct water to at least one radiator used for space heating within the building.

[0090] The advantage of this controller design is that heat energy from the outside air can be (directly) transferred to at least one space within the building. Therefore, heat can be directly pumped from the outdoor air into the building's radiator circuit.

[0091] The controller can be configured as follows:

[0092] If defrosting of the outdoor heat exchanger is not required

[0093] If the determined heating state of the second storage device is at or above the set lower limit

[0094] If there is a need for heating within the building, and

[0095] If the determined heating state of the first storage device is at or above a set lower limit, and if the determined outdoor air temperature is below a set lower limit for the outdoor ambient air temperature,

[0096] This allows heat from the first phase change material heat exchanger to be transferred to the heat medium heat exchanger, especially before the determined charging state of the second storage device is at or above a set upper limit.

[0097] The controller is preferably configured such that, especially before the determined heating state of the second storage device is at or above a set upper limit,

[0098] i) Set the four-way switching valve to a position that allows refrigerant to flow from the first phase change material heat exchanger via the compressor to the heat medium heat exchanger;

[0099] ii) Set the first three-way valve to direct refrigerant from the compressor to the heat medium heat exchanger;

[0100] iii) Set the second three-way valve to guide the refrigerant from the first phase change material heat exchanger to the compressor;

[0101] iv) Jointly adjust the orifice of the first expansion valve and the orifice of the second expansion valve to control evaporator overheating and compressor undercooling; and

[0102] v) Configure the third three-way valve to direct water to at least one radiator used for space heating within the building.

[0103] The advantage of this controller configuration is that thermal energy from the first storage device can be (directly) transferred to at least one space in the building. Therefore, heat can be pumped directly from the first storage device (containing a lower-temperature phase change material) to the building's radiator circuit.

[0104] The controller can be configured as follows:

[0105] If defrosting of the outdoor heat exchanger is not required

[0106] If the determined heating state of the second storage device is at or above the set lower limit

[0107] If there is no need for indoor heating in the building, and

[0108] If the determined heating state of the first storage device is lower than the set lower limit...

[0109] This allows heat from the outdoor heat exchanger to be transferred to the first phase change material heat exchanger, especially before the determined charging state of the second storage device is at or above a set upper limit.

[0110] The controller is preferably configured such that, especially before the determined heating state of the second storage device is at or above a set upper limit,

[0111] i) Set the four-way switching valve to a position that allows refrigerant to flow from the outdoor heat exchanger through the compressor to the first phase change material heat exchanger;

[0112] ii) Set the first three-way valve to direct refrigerant from the compressor to the first phase change material heat exchanger;

[0113] iii) Set the second three-way valve to direct refrigerant from the outdoor heat exchanger to the compressor;

[0114] iv) Jointly adjust the orifice of the first expansion valve and the orifice of the second expansion valve to control evaporator overheating and compressor undercooling.

[0115] The advantage of this controller design is that the first storage device can be heated using thermal energy from the outside air.

[0116] The system's heat medium circuit may include another heat exchanger adapted to exchange heat between water (flowing in the heat medium circuit) and tap water (flowing in the domestic hot water circuit). The advantage of this other heat exchanger is that it can provide heat to the tap water near the second phase change material heat exchanger of the second storage device. For example, the other heat exchanger may be located upstream of the second phase change material heat exchanger of the second storage device. This positioning allows the other heat exchanger to preheat the tap water before it enters the second phase change material heat exchanger of the second storage device. Alternatively, the other heat exchanger may be located downstream of the second phase change material heat exchanger of the second storage device. This positioning allows the other heat exchanger to subsequently heat the tap water flowing out of the second phase change material heat exchanger of the second storage device. In this embodiment, the heat medium circuit preferably includes another three-way valve adapted to switch the water flow to flow via the other heat exchanger to the second phase change material heat exchanger of the second storage device, or to flow directly to the second phase change material heat exchanger of the second storage device by bypassing the other heat exchanger.

[0117] The first storage device of the system may include a renewable energy heat exchanger adapted to exchange heat between the first phase change material and a fluid receiving heat energy from a renewable energy source. An advantage of this embodiment is that heat energy from the renewable energy source can be delivered to the first storage device and stored by the first phase change material within the first storage device. The renewable energy source may be a solar thermal array. In this case, water can flow through the solar thermal array, absorb heat energy from the sun, and transport the absorbed heat energy to the first storage device via the renewable energy heat exchanger. In a particularly preferred embodiment, the renewable energy source is a solar photovoltaic thermal array. In this case, water can flow through the solar photovoltaic thermal array, absorb heat energy from the sun, and transport the absorbed heat energy to the first storage device via the renewable energy heat exchanger. Furthermore, the electrical energy generated by the solar photovoltaic thermal array can be used to power the system, i.e., it can be used to operate the entire system or at least some parts of the system (e.g., those related to a heat pump). In this embodiment, the system may also include an inverter to convert DC voltage to AC voltage.

[0118] According to the present invention, a method for providing domestic hot water (DHW) and / or space heating (SH) within a building is provided, the method comprising:

[0119] a) A system comprising:

[0120] Refrigeration circuit, the refrigeration circuit comprising:

[0121] As a heat transfer medium, refrigerant

[0122] compressor,

[0123] Expansion valve 1 and expansion valve 2,

[0124] The first three-way valve and the second three-way valve,

[0125] Four-way switching valve

[0126] An outdoor heat exchanger, the outdoor heat exchanger being adapted to perform heat exchange between the refrigerant and air, and

[0127] A first storage device, the first storage device comprising a first phase change material, wherein,

[0128] The first storage device includes a first detector for determining the thermal state of the first storage device, and includes a first phase change material heat exchanger adapted to perform heat exchange between the refrigerant and the first phase change material;

[0129] The heat transfer medium circuit includes:

[0130] Water as a heat medium

[0131] A second storage device, thermally connected to a domestic hot water circuit and comprising a second phase change material, wherein the phase change temperature of the second phase change material is higher than that of the first phase change material, wherein the second storage device includes a second detector for determining the thermal charge state of the second storage device, and includes a second phase change material heat exchanger adapted to facilitate heat exchange between the water in the heat medium circuit and the second phase change material.

[0132] A third three-way valve, adapted to switch water flow to at least one radiator for space heating within a building or to the second phase change material heat exchanger, and

[0133] At least one conveying mechanism for circulating water through a heat medium heat exchanger;

[0134] A heat exchanger for a heat medium, comprising the refrigeration circuit and the heat medium circuit, and adapted to transfer heat between the refrigerant and water; and

[0135] Controller

[0136] b) The operation of the system is controlled at least based on the thermal state of the first storage device determined by information obtained from the first detector and the thermal state of the second storage device determined by information obtained from the second detector.

[0137] The advantages of this method are at least that it can provide domestic hot water and space heating in buildings in a more efficient manner and with minimal space requirements.

[0138] The first storage device of the system used in the method can be located outdoors, preferably inside the outdoor unit of the heat pump, which includes the compressor, the first expansion valve, the second expansion valve, the first three-way valve, the second three-way valve, the four-way switching valve, the outdoor heat exchanger, and the heat medium heat exchanger. The advantages are that implementing the method requires less indoor space and results in more efficient operation.

[0139] The method is characterized in that, if defrosting of the outdoor heat exchanger is required...

[0140] This allows heat from the first phase change material heat exchanger to be transferred to the outdoor heat exchanger.

[0141] The preferred method includes the following steps:

[0142] i) Set the four-way switching valve to a position that allows refrigerant to flow from the first phase change material heat exchanger via the compressor to the outdoor heat exchanger;

[0143] ii) Configure the first three-way valve to direct refrigerant from the first phase change material heat exchanger to the compressor;

[0144] iii) Set the second three-way valve to direct refrigerant from the compressor to the outdoor heat exchanger; and

[0145] iv) Jointly adjust the orifice of the first expansion valve and the orifice of the second expansion valve to control evaporator overheating and compressor undercooling.

[0146] The advantage of this method is that the heat stored in the second storage device can be used to defrost the outdoor heat exchanger in colder environments without compromising the comfort of the interior living space or the supply temperature of domestic hot water.

[0147] The method may be characterized in that...

[0148] If defrosting of the outdoor heat exchanger is not required

[0149] If the determined heating state of the second storage device is lower than the set lower limit, and

[0150] If the determined heating state of the first storage device is lower than a set lower limit, or if the determined outdoor air temperature is at or above a set lower limit for the outdoor ambient air temperature,

[0151] This allows heat from the outdoor heat exchanger to be transferred to the heat medium heat exchanger, especially before the determined charging state of the second storage device is at or above a set upper limit.

[0152] Preferably, this includes the following steps: especially before the determined heating state of the second storage device is at or above a set upper limit,

[0153] i) Set the four-way switching valve to a position that allows refrigerant to flow from the outdoor heat exchanger through the compressor to the heat medium heat exchanger;

[0154] ii) Set the first three-way valve to direct refrigerant from the compressor to the heat medium heat exchanger;

[0155] iii) Set the second three-way valve to direct refrigerant from the outdoor heat exchanger to the compressor;

[0156] iv) Jointly adjust the orifice of the first expansion valve and the orifice of the second expansion valve to control evaporator overheating and compressor undercooling; and

[0157] v) Set the third three-way valve to direct water to the second phase change material heat exchanger.

[0158] The advantage of this method is that the second storage device can be heated using heat energy from the outside air.

[0159] The method may be characterized in that...

[0160] If defrosting of the outdoor heat exchanger is not required

[0161] If the determined heating state of the second storage device is lower than the set lower limit, and

[0162] If the determined heating state of the first storage device is at or above a set lower limit, and if the determined outdoor air temperature is below a set lower limit for the outdoor ambient air temperature,

[0163] This allows heat from the first phase change material heat exchanger to be transferred to the heat medium heat exchanger, especially before the determined charging state of the second storage device is at or above a set upper limit.

[0164] Preferably, this includes the following steps: especially before the determined heating state of the second storage device is at or above a set upper limit,

[0165] i) Set the four-way switching valve to a position that allows refrigerant to flow from the first phase change material heat exchanger via the compressor to the heat medium heat exchanger;

[0166] ii) Set the first three-way valve to direct refrigerant from the compressor to the heat medium heat exchanger;

[0167] iii) Set the second three-way valve to guide the refrigerant from the first phase change material heat exchanger to the compressor;

[0168] iv) Jointly adjust the orifice of the first expansion valve and the orifice of the second expansion valve to control evaporator overheating and compressor undercooling; and

[0169] v) Set the third three-way valve to direct water to the second phase change material heat exchanger.

[0170] The advantage of this method is that the second storage device can be heated using the heat energy from the first storage device.

[0171] The method may be characterized in that...

[0172] If defrosting of the outdoor heat exchanger is not required

[0173] If the determined heating state of the second storage device is at or above a set lower limit...

[0174] If there is a need for heating within the building, and

[0175] If the determined heating state of the first storage device is lower than a set lower limit, or if the determined outdoor air temperature is at or above a set lower limit for the outdoor ambient air temperature,

[0176] This allows heat from the outdoor heat exchanger to be transferred to the heat medium heat exchanger, wherein the following steps are preferably included:

[0177] i) Set the four-way switching valve to a position that allows refrigerant to flow from the outdoor heat exchanger through the compressor to the heat medium heat exchanger;

[0178] ii) Set the first three-way valve to direct refrigerant from the compressor to the heat medium heat exchanger;

[0179] iii) Set the second three-way valve to direct refrigerant from the outdoor heat exchanger to the compressor;

[0180] iv) Jointly adjust the orifice of the first expansion valve and the orifice of the second expansion valve to control evaporator overheating and compressor undercooling; and

[0181] v) Configure the third three-way valve to direct water to at least one radiator used for space heating within the building.

[0182] The advantage of this method is that heat energy from the outside air can be (directly) transferred to at least one space within the building. Therefore, heat can be directly pumped from the outdoor air into the building's radiator circuit.

[0183] The method may be characterized in that...

[0184] If defrosting of the outdoor heat exchanger is not required

[0185] If the determined heating state of the second storage device is at or above a set lower limit...

[0186] If there is a need for heating within the building, and

[0187] If the determined heating state of the first storage device is at or above a set lower limit, and if the determined outdoor air temperature is below a set lower limit for the outdoor ambient air temperature,

[0188] This allows heat from the first phase change material heat exchanger to be transferred to the heat medium heat exchanger, especially before the determined charging state of the second storage device is at or above a set upper limit.

[0189] Preferably, this includes the following steps: especially before the determined heating state of the second storage device is at or above a set upper limit,

[0190] i) Set the four-way switching valve to a position that allows refrigerant to flow from the first phase change material heat exchanger via the compressor to the heat medium heat exchanger;

[0191] ii) Set the first three-way valve to direct refrigerant from the compressor to the heat medium heat exchanger;

[0192] iii) Set the second three-way valve to guide the refrigerant from the first phase change material heat exchanger to the compressor;

[0193] iv) Jointly adjust the orifice of the first expansion valve and the orifice of the second expansion valve to control evaporator overheating and compressor undercooling; and

[0194] v) Set the third three-way valve to direct water to at least one radiator used for space heating within the building.

[0195] The advantage of this method is that the heat energy from the first storage device can be (directly) transferred to at least one space in the building. Therefore, heat can be directly pumped from the first storage device (containing a lower-temperature phase change material) to the building's radiator circuit.

[0196] The method may be characterized in that...

[0197] If defrosting of the outdoor heat exchanger is not required

[0198] If the determined heating state of the second storage device is at or above a set lower limit...

[0199] If there is no need for indoor heating in the building, and

[0200] If the determined heating state of the first storage device is lower than the set lower limit...

[0201] This allows heat from the outdoor heat exchanger to be transferred to the first phase change material heat exchanger, especially before the determined charging state of the second storage device is at or above a set upper limit.

[0202] Preferably, this includes the following steps: especially before the determined heating state of the second storage device is at or above a set upper limit,

[0203] i) Set the four-way switching valve to a position that allows refrigerant to flow from the outdoor heat exchanger through the compressor to the first phase change material heat exchanger;

[0204] ii) Set the first three-way valve to direct refrigerant from the compressor to the first phase change material heat exchanger;

[0205] iii) Set the second three-way valve to direct refrigerant from the outdoor heat exchanger to the compressor;

[0206] iv) Jointly adjust the orifice of the first expansion valve and the orifice of the second expansion valve to control evaporator overheating and compressor undercooling.

[0207] The advantage of this method is that the first storage device can be heated using heat energy from the outside air.

[0208] In the method, the system according to the invention can be set up and used; that is, the method can be implemented using the system according to the invention. The controller of the system can be configured to control the steps of the method, for example, to control the settings of some parts of the system. Attached Figure Description

[0209] Figure 1A system according to the present invention is shown.

[0210] Figure 2 The components associated with the refrigeration circuit 30 of the system according to the invention are shown schematically.

[0211] Figure 3 It shows Figure 2 The components shown are illustrated, and the refrigerant flow direction is displayed in the first operating mode (heat pump mode 1).

[0212] Figure 4 It shows Figure 2 The components shown also illustrate the refrigerant flow in the second operating mode (heat pump mode 2) and the fifth operating mode (heat pump mode 5).

[0213] Figure 5 It shows Figure 2 The components shown also illustrate the refrigerant flow in the third operating mode (heat pump mode 3) and the fourth operating mode (heat pump mode 4).

[0214] Figure 6 It shows Figure 2 The components shown are illustrated, and the refrigerant flow direction is displayed in the sixth heating operation mode (heat pump mode 6).

[0215] Figure 7 A decision tree is schematically illustrated for implementing the method according to the invention and can be implemented in the controller of the system according to the invention.

[0216] Figure 8 The invention is shown to have Figure 1 Another system with the features shown.

[0217] Figure 9 The invention is shown to have Figure 1 Another system with the features shown. Detailed Implementation

[0218] The subject matter according to the invention is to be described in more detail with reference to the following figures and embodiments, without limiting the subject matter to the specific embodiments shown herein.

[0219] Figure 1 A system according to the present invention is shown. From the... Figure 1As can be seen, the system includes a first storage device 5, which contains a first phase change material (not shown) and includes a first phase change material heat exchanger 6 and a first detector (not shown) for determining the thermal state of the first storage device. The system also includes a second storage device 7, which contains a second phase change material (not shown) having a higher phase change temperature than the first phase change material and includes a second phase change material heat exchanger 8. The heat medium circuit 22 includes a three-way valve to switch the direction of water flow to either the second phase change material heat exchanger 8 or the radiator 18. The heat medium circuit 22 also includes a pump 10 for conveying water through the heat medium circuit 22. The system also includes a heat medium heat exchanger 11, which is configured via a refrigeration circuit and the heat medium circuit, and is adapted to transfer heat between the refrigerant and the water in the heat medium circuit 22.

[0220] Figure 2 The components of the system according to the invention, related to the refrigeration circuit 30, are schematically shown. As can be seen from the figure, the refrigeration circuit 30 includes a compressor 1, a first expansion valve 2, a second expansion valve 2', a four-way switching valve 3, an outdoor heat exchanger 4, and a first storage device 5. The first storage device 5 contains a first phase change material (not shown) and includes a first phase change material heat exchanger 6 and a first detector (not shown) for determining the charge state of the first storage device. The refrigeration circuit also includes a first three-way valve 13, a second three-way valve 14, and a receiving device located between the first expansion valve 2 and the second expansion valve 2'. Furthermore, the system includes a heat medium heat exchanger 11, which is formed by the refrigeration circuit 30 and the heat medium circuit, and is adapted to transfer heat between the refrigerant in the refrigeration circuit 30 and the water in the heat medium circuit; that is, a cold water flow 28 from the heat medium circuit can be heated in the heat medium heat exchanger 11 and exit the heat medium heat exchanger 11 as a hot water flow 29 to reach the heat medium circuit.

[0221] Figure 3 It shows Figure 2 The components are shown, and the flow of refrigerant is illustrated in the first operating mode (heat pump mode (HP mode) 1). In heat pump mode 1, outside air 16 is used as a heat source. Heat is transferred to the first storage device 5 (to allow the first storage device 5 to be efficiently heated).

[0222] Figure 4 It shows Figure 2The components are shown, and the refrigerant flow is illustrated in the second operating mode (heat pump mode 2) and the fifth operating mode (heat pump mode 5). In heat pump modes 2 and 5, the first storage unit 5 is used as a heat source. In heat pump mode 2, heat is transferred to the second storage unit 7 to charge it (so that domestic hot water can be provided efficiently), while in heat pump mode 5, heat is transferred to one or more radiators 18 in the building (so that heat can be provided efficiently in one or more rooms in the building). Switching between heat pump mode 2 and heat pump mode 5 can be performed by switching the three-way valve 9 of the heat transfer medium circuit.

[0223] Figure 5 It shows Figure 2 The components shown illustrate the refrigerant flow in the third operating mode (heat pump mode 3) and the fourth operating mode (heat pump mode 4). In heat pump modes 3 and 4, outside air 16 is used as a heat source. In heat pump mode 3, heat is transferred to the second storage unit 7 to charge it (to allow for efficient provision of domestic hot water), while in heat pump mode 4, heat is transferred to one or more radiators 18 in the building (to allow for efficient provision of heat in one or more rooms in the building). Switching between heat pump mode 3 and heat pump mode 4 can be performed by switching the three-way valve 9 of the heat transfer medium circuit.

[0224] Figure 6 It shows Figure 2 The components are shown, and the refrigerant flow is illustrated in the sixth heating operation mode (heat pump mode 6). In heat pump mode 6, the first storage device 5 is used as a heat source. Heat is transferred to the outdoor heat exchanger 4 (to allow for efficient defrosting of the outdoor heat exchanger).

[0225] Figure 7 A decision tree is schematically illustrated for implementing the method according to the invention and can be implemented in the controller of the system according to the invention.

[0226] Figure 8 The invention is shown to have Figure 1Another system with the features shown includes a heat exchanger 23 (preheating heat exchanger) in which the heat medium circuit 22 further comprises a heat exchanger 23 adapted to directly exchange heat between the water in the heat medium circuit 22 and the tap water flow 19. The heat exchanger 23 is adapted to preheat the tap water before it enters the second storage device 7, in which the preheated tap water is further heated by the second phase change material heat exchanger 8 and exits the second storage device as the domestic hot water flow 20. Specifically, the second storage device 7 includes two heat exchanger coils in contact with the phase change material (PCM). One heat exchanger coil is used to transfer heat from the heat medium circuit to the phase change material, and the other heat exchanger coil is used to transfer the stored heat from the phase change material to the domestic hot water flow. The heat medium circuit 22 may include another three-way valve 24, which is adapted to switch the water flow in the heat medium circuit 22 to the second phase change material heat exchanger 8 or the heat exchanger 23, allowing selection of whether the tap water should be preheated.

[0227] Figure 9 The invention is shown to have Figure 1 Another system shown includes a solar photovoltaic thermal array 26 (PVT array). As shown, the solar photovoltaic thermal array 26 can provide heat to the first storage container 5 via a renewable energy heat exchanger 25 located in the first storage container 5, and can also provide electrical energy to these parts of the system associated with the heat pump 17. For this purpose, the system may include an inverter 27 adapted to convert DC voltage to AC voltage.

[0228] Example 1—Outdoor air as a heat source for heating the first storage container ( Figure 3 )

[0229] Heat pump mode 1—Heating the first storage device from the gas source

[0230] In this operating mode, the heat pump is used to pump heat from the outdoor air 16 to the first storage device 5 via the first phase change material heat exchanger 6 embedded in the first storage device 5. The flow configuration of the refrigeration circuit is based on... Figure 3 Configure the settings.

[0231] The four-way switching valve 3 is set to its normal "heating" position. The three-way valve 13 is configured to guide superheated refrigerant vapor from the discharge port of the compressor 1 to the first heat exchanger 6, where the superheated refrigerant vapor condenses and releases heat to melt the first phase change material. The three-way valve 14 is configured to guide the two-phase refrigerant leaving the linear expansion valve 2 to the outdoor heat exchanger 4, where the two-phase refrigerant evaporates and absorbs heat from the airflow. The orifice of the first linear expansion valve 2 is adjusted to control the superheated temperature at the evaporator outlet, while the second linear expansion valve 2' is set to be fully open.

[0232] Example 2—The first storage device serves as a heat source for providing domestic hot water and / or space heating within a building. Figure 4 )

[0233] Heat pump mode 2—Heating the second storage device from the first storage device source.

[0234] In this operating mode, the heat pump is used to pump heat from the first storage device 5 to the second storage device 7, which allows for the efficient supply of domestic hot water through the second storage device. This mode is used when the outdoor air temperature is low enough that using the heat stored in the first storage device 5 as a heat source significantly improves the performance parameters of the heat pump compared to using outdoor air 16 as a heat source. The flow configuration of the refrigeration circuit is based on... Figure 4 Configure the settings.

[0235] The four-way switching valve 3 is set to its normal "heating" position. The three-way valve 13 is configured to guide superheated refrigerant vapor from the discharge port of the compressor 1 to the heat medium heat exchanger 11, where the superheated refrigerant vapor condenses and releases heat to the primary circulating fluid. The three-way valve 14 is configured to guide the two-phase refrigerant leaving the linear expansion valve 2 to the first storage device 5, where the two-phase refrigerant evaporates and absorbs heat from the first phase change material, which changes from a liquid phase to a solid phase. The orifice of the first linear expansion valve 2 is adjusted to control the superheated temperature at the evaporator outlet, while the second linear expansion valve 2' is set to be fully open.

[0236] The three-way valve 9 (in) Figure 1 (As shown in the figure) is configured to direct the water in the heat medium circuit 22 to the second storage device 7, instead of to the radiator 18.

[0237] Heat pump mode 5—space heating from the first storage device source

[0238] In this operating mode, the heat pump is used to pump heat from the first storage device 5 to at least one radiator 18, allowing for efficient heating of at least one indoor room where the radiator is located. This mode is used when the outdoor air temperature is sufficiently low and the heat demand is sufficiently high, such that using the heat stored in the first storage device 5 as a heat source significantly improves the performance parameters of the heat pump compared to using outdoor air 16 as a heat source. The flow configuration of the refrigeration circuit is based on... Figure 4 Configure the settings.

[0239] The four-way switching valve 3 is set to its normal "heating" position. The three-way valve 13 is configured to guide superheated refrigerant vapor from the discharge port of the compressor 1 to the heat medium heat exchanger 11, where the superheated refrigerant vapor condenses and releases heat to the primary circulating fluid. The three-way valve 14 is configured to guide the two-phase refrigerant leaving the linear expansion valve 2 to the first storage device 5, where the two-phase refrigerant evaporates and absorbs heat from the first phase change material, which changes from a liquid phase to a solid phase. The orifice of the first linear expansion valve 2 is adjusted to control the superheated temperature at the evaporator outlet, while the second linear expansion valve 2' is set to be fully open.

[0240] Three-way valve 9 (in) Figure 1 (As shown in the figure) is configured to direct the water in the heat medium circuit 22 to the radiator 18, instead of to the second storage device 7.

[0241] Example 3—Outdoor air as a heat source for providing domestic hot water and / or space heating within a building ( Figure 5 )

[0242] Heat pump mode 3—Heating the second storage unit from outdoor air source

[0243] In this operating mode, the heat pump is used to pump heat from outdoor air 16 to the second storage unit 7. This mode is used when there is a direct demand for domestic hot water (DHW) but insufficient heat energy is stored in the first storage unit 5, or when the temperature of outdoor air 16 is high enough that using the heat stored in the first storage unit 5 as a heat source does not significantly improve the heat pump's performance parameters compared to using outdoor air 16 as a heat source. The flow configuration of the refrigeration circuit is based on... Figure 5 Configure the settings.

[0244] The four-way switching valve 3 is set to its normal "heating" position. The three-way valve 13 is configured to guide superheated refrigerant vapor from the compressor 1 discharge port to the heat medium heat exchanger 11, where the superheated refrigerant vapor condenses and releases heat to the primary circulation fluid. The three-way valve 14 is configured to guide the two-phase refrigerant leaving the linear expansion valve 2 to the outdoor heat exchanger 4, where the two-phase refrigerant evaporates and absorbs heat from the airflow. The orifice of the first linear expansion valve 2 is adjusted to control the superheated temperature at the evaporator outlet, while the second linear expansion valve 2' is set to be fully open.

[0245] The three-way valve 9 (in) Figure 1 (As shown in the figure) is configured to direct the water in the heat medium circuit 22 to the second storage device 7, instead of to the radiator 18.

[0246] Heat pump mode 4—Using outdoor air source for space heating

[0247] In this operating mode, the heat pump is used to pump heat from outdoor air 16 to radiator 18. This mode is used when the temperature of outdoor air 16 is sufficiently high and the heat demand is sufficiently low, such that using the heat stored in the first storage device 5 as a heat source does not significantly improve the performance parameters of the heat pump compared to using outdoor air 16 as a heat source. The flow configuration of the refrigeration circuit is based on... Figure 5 Configure the settings.

[0248] The four-way switching valve 3 is set to its normal "heating" position. The three-way valve 13 is configured to guide superheated refrigerant vapor from the compressor 1 discharge port to the heat medium heat exchanger 11, where the superheated refrigerant vapor condenses and releases heat to the primary circulation fluid. The three-way valve 14 is configured to guide the two-phase refrigerant leaving the linear expansion valve 2 to the outdoor heat exchanger 4, where the two-phase refrigerant evaporates and absorbs heat from the airflow. The orifice of the first linear expansion valve 2 is adjusted to control the superheated temperature at the evaporator outlet, while the second linear expansion valve 2' is set to be fully open.

[0249] The three-way valve 9 (in) Figure 1 (As shown in the figure) is configured to direct the water in the heat medium circuit to the radiator 18 instead of to the second storage device 7.

[0250] Example 4—The first storage device serves as a heat source for defrosting the outdoor heat exchanger. Figure 6 )

[0251] Heat pump mode 6—Defrosting the outdoor heat exchanger using the heat stored in the first storage device.

[0252] In this operating mode, the heat pump is used to pump heat from the first storage device 5 to defrost the outdoor heat exchanger 4 (periodically) during periods of colder outdoor temperatures. The flow configuration of the refrigeration circuit is based on... Figure 6 set up.

[0253] The four-way switching valve 3 is set in its reverse "defrost" position. Low-pressure two-phase refrigerant enters the first phase change material heat exchanger 6, where it evaporates and absorbs the latent heat released by the first phase change material. The three-way valve 13 is configured to guide the low-pressure vapor leaving the first phase change material heat exchanger 6 to the inlet of the compressor 1. The three-way valve 14 guides the high-pressure superheated vapor leaving the compressor 1 discharge port to the outdoor heat exchanger 4, where it condenses and releases heat to defrost the ice buildup on the outer surface of the outdoor heat exchanger 4. The orifice of the second linear expansion valve 2' is adjusted to control the superheated temperature at the outlet of the first phase change material heat exchanger 6, while the first linear expansion valve 2' is set to be fully open.

[0254] Example 5—Another heat exchanger for preheating tap water ( Figure 8 )

[0255] Figure 8 One possible implementation is shown in which the heat pump (using air or the first storage device 5 as a heat source), another heat exchanger (e.g., a plate heat exchanger), and another three-way valve 24 in the heat medium circuit are used to preheat tap water.

[0256] This arrangement is particularly advantageous during longer periods of domestic hot water dispensing (e.g., bathing or showering), reducing the proportion of domestic hot water heat load drawn from the second storage unit 7 by up to 20-50% (depending on the nominal capacity of the heat pump). Therefore, a larger volume of domestic hot water can be supplied before the second storage unit 7 needs to be charged, or the size of the second storage unit 7 can be smaller when a comparable volume of domestic hot water needs to be supplied, resulting in the second storage unit 7 occupying less indoor space.

[0257] Example 6—A solar thermal array or a solar PVT array as a heat source for heating the first storage device ( Figure 9 )

[0258] By incorporating a dual heat exchanger design into the first storage unit 5, a second renewable heat source, such as a solar collector array, can be used to provide heat input to the system. This has a particular advantage in this arrangement because, compared to conventional arrangements that require heating domestic hot water to a higher storage temperature of approximately 60°C using solar collectors, the solar collector array can operate at a lower melting temperature in the first storage unit 5. This means that, compared to those more expensive designs (such as evacuated tube collectors), lower-cost solar collector designs (such as unglazed flat plate collectors) can be used, which typically experience a more significant drop in efficiency at higher operating temperatures.

[0259] More preferably, instead of using a solar thermal array, a hybrid photovoltaic (PVT) collector array is used, in which photovoltaic cells and solar collectors are combined in the same module. These are typically designed for lower operating temperatures in order to maintain both high photovoltaic power generation efficiency and reasonable solar thermal efficiency. Figure 9 A recommended arrangement of a system incorporating a PVT array is shown. Using photovoltaic thermal collectors is highly advantageous because the electricity generated by the PVT array can be used to operate the entire system or at least some of its components (e.g., the portion associated with the heat pump). Therefore, the system can operate entirely or at least partially using renewable energy sources (i.e., solar energy).

[0260] List of reference numerals and abbreviations

[0261] 1: Compressor;

[0262] 2: First expansion valve;

[0263] 2': Second expansion valve;

[0264] 3: Four-way switching valve;

[0265] 4: Outdoor heat exchanger;

[0266] 5: A first storage device containing the first phase change material;

[0267] 6: First phase change material heat exchanger;

[0268] 7: A second storage device containing a second phase change material;

[0269] 8: Second phase change material heat exchanger;

[0270] 9: Third three-way valve (three-way valve for the hot medium circuit);

[0271] 10: Transport mechanism for heat medium circuits (e.g., pump);

[0272] 11: Heat exchanger for heat transfer medium;

[0273] 12: Controller;

[0274] 13: First three-way valve (first three-way valve in the refrigeration circuit);

[0275] 14: Second three-way valve (second three-way valve in the refrigeration circuit);

[0276] 15: Receiving device for the refrigeration circuit;

[0277] 16: Outdoor air;

[0278] 17: Dual heat source / dual heat sink heat pump;

[0279] 18: Radiators used for space heating;

[0280] 19: The flow of tap water;

[0281] 20: The flow of hot water for domestic use;

[0282] 21: Integrated outdoor unit;

[0283] 22: Heat transfer medium circuit;

[0284] 23: Preheating heat exchanger for the heat medium circuit;

[0285] 24: Another three-way valve in the heat medium circuit;

[0286] 25: Renewable energy heat exchangers;

[0287] 26: Renewable energy sources (PVT array);

[0288] 27: Inverter;

[0289] 28: Cold water flow from the heat medium loop;

[0290] 29: Hot water flow towards the heat medium circuit;

[0291] 30: Refrigeration circuit;

[0292] SOC1: The thermal state of the first phase change material;

[0293] SOC2: The thermal state of the second phase change material;

[0294] LL1: Lower limit of SOC1 setting;

[0295] LL2: Lower limit of SOC2 setting;

[0296] UL1: The upper limit of SOC1 setting;

[0297] UL2: The upper limit of SOC2 settings;

[0298] TOA Outdoor ambient air temperature;

[0299] LL TOA The lower limit for outdoor ambient air temperature;

[0300] DHW: Domestic hot water;

[0301] SH: (Interior) Heating;

[0302] HP mode: Heat pump mode.

Claims

1. A system for providing domestic hot water (DHW) and / or space heating (SH) within a building, the system comprising: a) A refrigeration circuit, the refrigeration circuit comprising: As a heat transfer medium, refrigerant Compressor (1), First expansion valve (2) and second expansion valve (2'). The first three-way valve (13) and the second three-way valve (14). Four-way switching valve (3). An outdoor heat exchanger (4), the outdoor heat exchanger being adapted to perform heat exchange between the refrigerant and the air, and A first storage device (5) comprising a first phase change material, wherein the first storage device (5) includes a first detector for determining the state of charge (SOC1) of the first storage device (5) and includes a first phase change material heat exchanger (6) adapted to perform heat exchange between the refrigerant and the first phase change material. b) A heat transfer medium circuit, the heat transfer medium circuit comprising: Water as a heat medium A second storage device (7) is thermally connected to a domestic hot water circuit and contains a second phase change material, wherein the phase change temperature of the second phase change material is higher than that of the first phase change material, wherein the second storage device (7) includes a second detector for determining the state of charge (SOC2) of the second storage device (7), and includes a second phase change material heat exchanger (8) adapted to perform heat exchange between the water in the heat medium circuit and the second phase change material. A third three-way valve (9), said third three-way valve being adapted to switch water flow to at least one radiator for space heating within the building or to the second phase change material heat exchanger (8), and At least one conveying mechanism (10) is provided for circulating water through a heat medium heat exchanger; c) A heat medium heat exchanger (11), which is configured via the refrigeration circuit and the heat medium circuit and is adapted to transfer heat between the refrigerant and the water; and d) Controller (12), the controller being configured to control the operation of the system based at least on the thermal state (SOC1) of the first storage device (5) determined by information obtained from the first detector and the thermal state (SOC2) of the second storage device (7) determined by information obtained from the second detector.

2. The system according to claim 1, characterized in that, The first storage device (5) is located outdoors and inside the outdoor heat pump unit, which includes the compressor (1), the first expansion valve (2), the second expansion valve (2'), the first three-way valve (13), the second three-way valve (14), the four-way switching valve (3), the outdoor heat exchanger (4), and the heat medium heat exchanger (11).

3. The system according to claim 1 or 2, characterized in that, The controller (12) is configured as follows: If defrosting of the outdoor heat exchanger (4) is required, This allows heat from the first phase change material heat exchanger (6) to be transferred to the outdoor heat exchanger (4). The controller (12) is configured as follows: i) Set the four-way switching valve (3) to a position that allows refrigerant to flow from the first phase change material heat exchanger (6) through the compressor (1) to the outdoor heat exchanger (4); ii) Set the first three-way valve (13) to guide the refrigerant from the first phase change material heat exchanger (6) to the compressor (1); iii) Set the second three-way valve (14) to direct refrigerant from the compressor (1) to the outdoor heat exchanger (4); and iv) Jointly adjust the orifice of the first expansion valve (2) and the orifice of the second expansion valve (2') to control evaporator overheating and compressor undercooling.

4. The system according to claim 1 or 2, characterized in that, The controller (12) is configured as follows: If defrosting of the outdoor heat exchanger (4) is not required, If the determined state of charge (SOC2) of the second storage device (7) is lower than the set lower limit (LL2), and If the determined state of charge (SOC1) of the first storage device (5) is lower than the set lower limit (LL1), or if the determined outdoor air temperature (T) OA ) at or above the set lower limit of outdoor ambient air temperature (LL) TOA ), This allows heat from the outdoor heat exchanger (4) to be transferred to the heat medium heat exchanger (11), especially before the determined state of charge (SOC2) of the second storage device (7) is at or above the set upper limit (UL2). The controller (12) is configured such that, particularly before the determined state of charge (SOC2) of the second storage device is at or above a set upper limit (UL2), i) Set the four-way switching valve (3) to a position that allows refrigerant to flow from the outdoor heat exchanger (4) through the compressor (1) to the heat medium heat exchanger (11); ii) Set the first three-way valve (13) to guide the refrigerant from the compressor (1) to the heat medium heat exchanger (11); iii) Set the second three-way valve (14) to direct refrigerant from the outdoor heat exchanger (4) to the compressor (1); iv) Jointly adjust the orifice of the first expansion valve (2) and the orifice of the second expansion valve (2') to control evaporator overheating and compressor undercooling; and v) Set the third three-way valve (9) to direct water to the second phase change material heat exchanger (8).

5. The system according to claim 1 or 2, characterized in that, The controller (12) is configured as follows: If defrosting of the outdoor heat exchanger (4) is not required, If the determined state of charge (SOC2) of the second storage device is lower than the set lower limit (LL2), and If the determined state of charge (SOC1) of the first storage device (5) is at or above the set lower limit (LL1), and if the determined outdoor air temperature (T) OA ) lower than the set lower limit of outdoor ambient air temperature (LL) TOA ), This allows heat from the first phase change material heat exchanger (6) to be transferred to the heat medium heat exchanger (11), especially before the determined state of charge (SOC2) of the second storage device (7) is at or above the set upper limit (UL2). The controller (12) is configured such that, particularly before the determined state of charge (SOC2) of the second storage device (7) is at or above a set upper limit (UL2), i) Set the four-way switching valve (3) to a position that allows refrigerant to flow from the first phase change material heat exchanger (6) via the compressor (1) to the heat medium heat exchanger (11); ii) Set the first three-way valve (13) to guide the refrigerant from the compressor (1) to the heat medium heat exchanger (11); iii) Set the second three-way valve (14) to guide the refrigerant from the first phase change material heat exchanger (6) to the compressor (1); iv) Jointly adjust the orifice of the first expansion valve (2) and the orifice of the second expansion valve (2') to control evaporator overheating and compressor undercooling; and v) Set the third three-way valve (9) to direct water to the second phase change material heat exchanger (8).

6. The system according to claim 1 or 2, characterized in that, The controller (12) is configured as follows: If defrosting of the outdoor heat exchanger (4) is not required, If the determined state of charge (SOC2) of the second storage device (7) is at or above the set lower limit (LL2). If there is a need for indoor space heating (SH) in the building, and If the determined state of charge (SOC1) of the first storage device (5) is lower than the set lower limit (LL1), or if the determined outdoor air temperature (T) OA ) at or above the set lower limit of outdoor ambient air temperature (LL) TOA ), This allows heat from the outdoor heat exchanger (4) to be transferred to the heat medium heat exchanger (11). The controller (12) is configured as follows: i) Set the four-way switching valve (3) to a position that allows refrigerant to flow from the outdoor heat exchanger (4) through the compressor (1) to the heat medium heat exchanger (11); ii) Set the first three-way valve (13) to guide the refrigerant from the compressor (1) to the heat medium heat exchanger (11); iii) Set the second three-way valve (14) to direct refrigerant from the outdoor heat exchanger (4) to the compressor (1); iv) Jointly adjust the orifice of the first expansion valve (2) and the orifice of the second expansion valve (2') to control evaporator overheating and compressor undercooling; and v) Set the third three-way valve (9) to direct water to at least one radiator for space heating within the building.

7. The system according to claim 1 or 2, characterized in that, The controller (12) is configured as follows: If defrosting of the outdoor heat exchanger (4) is not required, If the determined state of charge (SOC2) of the second storage device (7) is at or above the set lower limit (LL2). If there is a need for indoor space heating (SH) in the building, and If the determined state of charge (SOC1) of the first storage device (5) is at or above the set lower limit (LL1), and if the determined outdoor air temperature (T) OA ) lower than the set lower limit of outdoor ambient air temperature (LL) TOA ), This allows heat from the first phase change material heat exchanger (6) to be transferred to the heat medium heat exchanger (11), especially before the determined state of charge (SOC2) of the second storage device (7) is at or above the set upper limit (UL2). The controller (12) is configured such that, particularly before the determined state of charge (SOC2) of the second storage device (7) is at or above a set upper limit (UL2), i) Set the four-way switching valve (3) to a position that allows refrigerant to flow from the first phase change material heat exchanger (6) via the compressor (1) to the heat medium heat exchanger (11); ii) Set the first three-way valve (13) to guide the refrigerant from the compressor (1) to the heat medium heat exchanger (11); iii) Set the second three-way valve (14) to guide the refrigerant from the first phase change material heat exchanger (6) to the compressor (1); iv) Jointly adjust the orifice of the first expansion valve (2) and the orifice of the second expansion valve (2') to control evaporator overheating and compressor undercooling; and v) Set the third three-way valve (9) to direct water to at least one radiator for space heating within the building.

8. The system according to claim 1 or 2, characterized in that, The controller (12) is configured as follows: If defrosting of the outdoor heat exchanger (4) is not required, If the determined state of charge (SOC2) of the second storage device (7) is at or above the set lower limit (LL2). If there is no need for indoor space heating (SH), and If the determined state of charge (SOC1) of the first storage device (5) is lower than the set lower limit (LL1). This allows heat from the outdoor heat exchanger (4) to be transferred to the first phase change material heat exchanger (6), especially before the determined state of charge (SOC2) of the second storage device (7) is at or above the set upper limit (UL2). The controller (12) is configured such that, particularly before the determined state of charge (SOC2) of the second storage device (7) is at or above a set upper limit (UL2), i) Set the four-way switching valve (3) to a position that allows refrigerant to flow from the outdoor heat exchanger (4) through the compressor (1) to the first phase change material heat exchanger (6); ii) Set the first three-way valve (13) to guide the refrigerant from the compressor (1) to the first phase change material heat exchanger (6); iii) Set the second three-way valve (14) to direct refrigerant from the outdoor heat exchanger (4) to the compressor (1); iv) Jointly adjust the orifice of the first expansion valve (2) and the orifice of the second expansion valve (2') to control evaporator overheating and compressor undercooling.

9. A method for providing domestic hot water (DHW) and / or space heating (SH) within a building, the method comprising: a) A system comprising: Refrigeration circuit, the refrigeration circuit comprising: As a heat transfer medium, refrigerant Compressor (1), First expansion valve (2) and second expansion valve (2'). The first three-way valve (13) and the second three-way valve (14). Four-way switching valve (3). An outdoor heat exchanger (4), the outdoor heat exchanger being adapted to perform heat exchange between the refrigerant and the air, and A first storage device (5) comprising a first phase change material, wherein the first storage device (5) includes a first detector for determining the state of charge (SOC1) of the first storage device (5) and includes a first phase change material heat exchanger (6) adapted to perform heat exchange between the refrigerant and the first phase change material. The heat transfer medium circuit includes: Water as a heat medium A second storage device (7) is thermally connected to a domestic hot water circuit and contains a second phase change material, wherein the phase change temperature of the second phase change material is higher than that of the first phase change material, wherein the second storage device (7) includes a second detector for determining the state of charge (SOC2) of the second storage device (7), and includes a second phase change material heat exchanger (8) adapted to perform heat exchange between the water in the heat medium circuit and the second phase change material. A third three-way valve (9), said third three-way valve being adapted to switch water flow to at least one radiator for space heating within the building or to the second phase change material heat exchanger (8), and At least one conveying mechanism (10) is provided for circulating water through a heat medium heat exchanger; A heat exchanger (11) for a heat medium, comprising the refrigeration circuit and the heat medium circuit, and adapted to transfer heat between the refrigerant and water; and Controller (12), b) The operation of the system is controlled at least based on the thermal state (SOC1) of the first storage device (5) determined by information obtained from the first detector and the thermal state (SOC2) of the second storage device (7) determined by information obtained from the second detector.

10. The method according to claim 9, characterized in that, The first storage device (5) is located outdoors and inside the outdoor heat pump unit, which includes the compressor (1), the first expansion valve (2), the second expansion valve (2'), the first three-way valve (13), the second three-way valve (14), the four-way switching valve (3), the outdoor heat exchanger (4), and the heat medium heat exchanger (11).

11. The method according to claim 9 or 10, characterized in that, If defrosting of the outdoor heat exchanger (4) is required, This allows heat from the first phase change material heat exchanger (6) to be transferred to the outdoor heat exchanger (4). This includes the following steps: i) Set the four-way switching valve (3) to a position that allows refrigerant to flow from the first phase change material heat exchanger (6) through the compressor (1) to the outdoor heat exchanger (4); ii) Set the first three-way valve (13) to guide the refrigerant from the first phase change material heat exchanger (6) to the compressor (1); iii) Set the second three-way valve (14) to direct refrigerant from the compressor (1) to the outdoor heat exchanger (4); and iv) Jointly adjust the orifice of the first expansion valve (2) and the orifice of the second expansion valve (2') to control evaporator overheating and compressor undercooling.

12. The method according to claim 9 or 10, characterized in that, If defrosting of the outdoor heat exchanger (4) is not required, If the determined state of charge (SOC2) of the second storage device (7) is lower than the set lower limit (LL2), and If the determined state of charge (SOC1) of the first storage device (5) is lower than the set lower limit (LL1), or if the determined outdoor air temperature (T) OA ) at or above the set lower limit of outdoor ambient air temperature (LL) TOA ), This allows heat from the outdoor heat exchanger (4) to be transferred to the heat medium heat exchanger (11), especially before the determined state of charge (SOC2) of the second storage device (7) is at or above the set upper limit (UL2). This includes the following steps: especially before the determined state of charge (SOC2) of the second storage device is at or above a set upper limit (UL2), i) Set the four-way switching valve (3) to a position that allows refrigerant to flow from the outdoor heat exchanger (4) through the compressor (1) to the heat medium heat exchanger (11); ii) Set the first three-way valve (13) to guide the refrigerant from the compressor (1) to the heat medium heat exchanger (11); iii) Set the second three-way valve (14) to direct refrigerant from the outdoor heat exchanger (4) to the compressor (1); iv) Jointly adjust the orifice of the first expansion valve (2) and the orifice of the second expansion valve (2') to control evaporator overheating and compressor undercooling; and v) Set the third three-way valve (9) to direct water to the second phase change material heat exchanger (8).

13. The method according to claim 9 or 10, characterized in that, If defrosting of the outdoor heat exchanger (4) is not required, If the determined state of charge (SOC2) of the second storage device (7) is lower than the set lower limit (LL2), and If the determined state of charge (SOC1) of the first storage device (5) is at or above the set lower limit (LL1), and if the determined outdoor air temperature (T) OA ) lower than the set lower limit of outdoor ambient air temperature (LL) TOA ), This allows heat from the first phase change material heat exchanger (6) to be transferred to the heat medium heat exchanger (11), especially before the determined state of charge (SOC2) of the second storage device (7) is at or above the set upper limit (UL2). This includes the following steps: especially before the determined state of charge (SOC2) of the second storage device (7) is at or above the set upper limit (UL2), i) Set the four-way switching valve (3) to a position that allows refrigerant to flow from the first phase change material heat exchanger (6) via the compressor (1) to the heat medium heat exchanger (11); ii) Set the first three-way valve (13) to guide the refrigerant from the compressor (1) to the heat medium heat exchanger (11); iii) Set the second three-way valve (14) to guide the refrigerant from the first phase change material heat exchanger (6) to the compressor (1); iv) Jointly adjust the orifice of the first expansion valve (2) and the orifice of the second expansion valve (2') to control evaporator overheating and compressor undercooling; and v) Set the third three-way valve (9) to direct water to the second phase change material heat exchanger (8).

14. The method according to claim 9 or 10, characterized in that, If defrosting of the outdoor heat exchanger (4) is not required, If the determined state of charge (SOC2) of the second storage device (7) is at or above the set lower limit (LL2). If there is a need for indoor space heating (SH) in the building, and If the determined state of charge (SOC1) of the first storage device (5) is lower than the set lower limit (LL1), or if the determined outdoor air temperature (T) OA ) at or above the set lower limit of outdoor ambient air temperature (LL) TOA ), This allows heat from the outdoor heat exchanger (4) to be transferred to the heat medium heat exchanger (11). This includes the following steps: i) Set the four-way switching valve (3) to a position that allows refrigerant to flow from the outdoor heat exchanger (4) through the compressor (1) to the heat medium heat exchanger (11); ii) Set the first three-way valve (13) to guide the refrigerant from the compressor (1) to the heat medium heat exchanger (11); iii) Set the second three-way valve (14) to direct refrigerant from the outdoor heat exchanger (4) to the compressor (1); iv) Jointly adjust the orifice of the first expansion valve (2) and the orifice of the second expansion valve (2') to control evaporator overheating and compressor undercooling; and v) Set the third three-way valve (9) to direct water to at least one radiator for space heating within the building.

15. The method according to claim 9 or 10, characterized in that, If defrosting of the outdoor heat exchanger (4) is not required, If the determined state of charge (SOC2) of the second storage device (7) is at or above the set lower limit (LL2). If there is a need for indoor space heating (SH) in the building, and If the determined state of charge (SOC1) of the first storage device (5) is at or above the set lower limit (LL1), and if the determined outdoor air temperature (T) OA ) lower than the set lower limit of outdoor ambient air temperature (LL) TOA ), This allows heat from the first phase change material heat exchanger (6) to be transferred to the heat medium heat exchanger (11), especially before the determined state of charge (SOC2) of the second storage device (7) is at or above the set upper limit (UL2). This includes the following steps: especially before the determined state of charge (SOC2) of the second storage device (7) is at or above the set upper limit (UL2), i) Set the four-way switching valve (3) to a position that allows refrigerant to flow from the first phase change material heat exchanger (6) via the compressor (1) to the heat medium heat exchanger (11); ii) Set the first three-way valve (13) to guide the refrigerant from the compressor (1) to the heat medium heat exchanger (11); iii) Set the second three-way valve (14) to guide the refrigerant from the first phase change material heat exchanger (6) to the compressor (1); iv) Jointly adjust the orifice of the first expansion valve (2) and the orifice of the second expansion valve (2') to control evaporator overheating and compressor undercooling; and v) Set the third three-way valve (9) to direct water to at least one radiator for space heating within the building.

16. The method according to claim 9 or 10, characterized in that, If defrosting of the outdoor heat exchanger (4) is not required, If the determined state of charge (SOC2) of the second storage device (7) is at or above the set lower limit (LL2). If there is no need for indoor space heating (SH), and If the determined state of charge (SOC1) of the first storage device (5) is lower than the set lower limit (LL1). This allows heat from the outdoor heat exchanger (4) to be transferred to the first phase change material heat exchanger (6), especially before the determined state of charge (SOC2) of the second storage device (7) is at or above the set upper limit (UL2). This includes the following steps: especially before the determined state of charge (SOC2) of the second storage device (7) is at or above the set upper limit (UL2), i) Set the four-way switching valve (3) to a position that allows refrigerant to flow from the outdoor heat exchanger (4) through the compressor (1) to the first phase change material heat exchanger (6); ii) Set the first three-way valve (13) to guide the refrigerant from the compressor (1) to the first phase change material heat exchanger (6); iii) Set the second three-way valve (14) to direct refrigerant from the outdoor heat exchanger (4) to the compressor (1); iv) Jointly adjust the orifice of the first expansion valve (2) and the orifice of the second expansion valve (2') to control evaporator overheating and compressor undercooling.

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