System for heating at least one space and for providing household hot water and method for operating system

Abstract

To provide a system for providing household hot water and heating at least one space, which has a small and compact design.SOLUTION: A system includes: a heat transfer device 19 for providing household hot water; at least one emitter 14 for heating at least one space; a fluid network for transferring a first heat transfer fluid; a first heat exchanger 15 for transferring heat between the first heat transfer fluid and a second heat transfer fluid; a second heat exchanger 21 for pre-heating water to be further heated by the heat transfer device to obtain household hot water; and a controller. The fluid network includes a heat pump unit 1, at least one valve, and pipes, and the heat pump unit includes a compressor and at least one expansion valve. The fluid network is configurable by the controller in a plurality of specific configurations, and the controller is configured such that it can operate the system in a plurality of specific modes.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a system for heating at least one space and providing domestic hot water. The system includes a heat transfer device for providing domestic hot water, at least one emitter provided in the at least one space for heating the at least one space, a reconfigurable fluid network for transporting a first heat transfer fluid, a first heat exchanger for transferring heat between the first heat transfer fluid and a second heat transfer fluid, a second heat exchanger for preheating water to be further heated by the heat transfer device to provide domestic hot water, and a controller. The reconfigurable fluid network includes a heat pump unit, at least one valve, and piping, the heat pump unit including a compressor and at least one expansion valve. The reconfigurable fluid network is configurable by the controller into a plurality of specific configurations, and the controller is configured to operate the system in a plurality of specific modes. The present invention also relates to a method for operating the system. [Background technology]

[0002] Water-to-water heat pumps are increasingly being installed in apartment buildings. They are installed in individual rooms to deliver hot water and space heating and can be connected to heat networks, such as fifth-generation ambient temperature district heating networks, that are deployed throughout the building. While typical air-to-water heat pumps have a heat pump refrigerant circuit in the outdoor unit and a domestic hot water (DHW) thermal energy storage (TES) in the indoor unit, these water-to-water heat pump systems combine the heat pump refrigerant circuit and TES in the indoor unit. In water-to-water heat pump systems, the heat pump is often located at the bottom of the indoor unit, and the cylinder at the top is used to provide domestic hot water (DHW).

[0003] Current water-to-water heat pump systems often have large indoor units and therefore require a lot of indoor space. This is mostly due to the DHW storage cylinder. However, because apartment buildings are very space-constrained, it may be difficult to install a heat pump indoor unit with an integrated DHW storage cylinder in an apartment building due to the lack of space. Summary of the Invention [Problem to be solved by the invention]

[0004] Starting from this, it was an object of the present invention to provide a system for providing domestic hot water and heating at least one space, which can be realized in a small and compact design so as to require a relatively small amount of indoor space (for installation). [Means for solving the problem]

[0005] This object is achieved with respect to a system for heating at least one space and providing domestic hot water by the features of claim 1 and with respect to a method for operating such a system by the features of claim 13. The dependent claims represent advantageous further developments.

[0006] According to the present invention, there is provided a system for heating at least one space and providing domestic hot water, comprising: a heat transfer device for providing domestic hot water; at least one emitter (heat radiator) provided in the at least one space for heating the at least one space; a reconfigurable fluid network for transporting a first heat transfer fluid, the reconfigurable fluid network including a heat pump unit, at least one valve, and piping, the heat pump unit including a compressor and at least one expansion valve, the reconfigurable fluid network being configurable by a controller into a plurality of configurations, the configurations including a first configuration in which the reconfigurable fluid network is configured to transport the first heat transfer fluid from the heat pump unit to a heat transfer device rather than to the at least one emitter (heat radiator), and a second configuration in which the reconfigurable fluid network is configured to transport the first heat transfer fluid from the heat pump unit to the at least one emitter (heat radiator) rather than to the heat transfer device; a first heat exchanger for transferring heat between a first heat transfer fluid and a second heat transfer fluid external to the reconfigurable fluid network, the first heat exchanger being external to the heat pump unit; a second heat exchanger for preheating mains water (to a preheated mains water temperature), which is further heated by a heat transfer device (to a domestic hot water outlet temperature) to obtain domestic hot water; the controller configured to operate the system in a plurality of modes, the plurality of modes including a (first) mode for providing domestic hot water, in which the reconfigurable fluid network is configured to be in a first configuration, and a (second) mode for heating at least one space, in which the reconfigurable fluid network is configured to be in a second configuration; A system is provided that includes:

[0007] The system according to the present invention includes a reconfigurable fluid network including a heat pump unit, a heat transfer device, at least one emitter for heating at least one space, and a first heat exchanger for transferring heat between a first heat transfer fluid and a second heat transfer fluid, all connected to the reconfigurable fluid network. The reconfigurable fluid network is configurable by a controller into a plurality of configurations capable of transporting the first heat transfer fluid through the piping of the reconfigurable fluid network between different components of the system. To change the configuration of the reconfigurable fluid network, for example, the controller can switch at least one valve (e.g., at least one three-way valve).

[0008] The plurality of configurations includes at least two configurations: In a first configuration, the reconfigurable fluid network is configured to transport the first heat transfer fluid from (a high pressure side of) the heat pump unit to (a back and forth) the heat transfer device but not to the at least one emitter; and In a second configuration, the reconfigurable fluid network is configured to transport the first heat transfer fluid from (a high pressure side of) the heat pump unit to (a back and forth) the at least one emitter but not to the heat transfer device.

[0009] In the system according to the invention, the mains water is preheated to the preheated mains water temperature by the second heat exchanger, after which the preheated mains water is further heated to the domestic hot water outlet temperature by the heat transfer device.

[0010] Since the system according to the present invention includes a second heat exchanger for preheating mains water to be further heated by the heat transfer device to provide domestic hot water, the heat transfer device does not need to be a large thermal energy storage device to provide domestic hot water, since the mains water heated by the heat transfer device to provide domestic hot water is already preheated and does not need to be heated significantly. Instead, it is sufficient to use a smaller device as the heat transfer device, such as a (third) heat exchanger or a small thermal energy storage device. As a result, since a small device can be used as the heat transfer device in the system according to the present invention, the system itself can also be designed to be more compact and compact. Therefore, the system can be realized in a small and compact design and requires a relatively small amount of indoor space (for installation). In particular, the system can be in the form of a small and compact unit, for example in the form of a small and compact indoor unit.

[0011] For example, chilled mains water could be preheated to a heat network temperature of, say, 25-40°C by a second heat exchanger that is itself heated by the heat network. In this exemplary case, the water-to-water heat pump does not require a 170 L DHW cylinder to provide DHW; instead, two alternatives are possible. The heat pump can directly heat the mains water to a supply temperature of at least 40°C via a (third) heat exchanger used as the heat transfer device. Alternatively, a small thermal energy storage device used as the heat transfer device can improve heat pump efficiency by preventing very short on-off cycling of the heat pump compressor for small DHW discharges. The small thermal energy storage device can be designed to discharge 5-50 L, preferably 5-20 L. The small thermal energy storage device preferably consists of a PCM as the thermal energy storage material, but can also consist of a sensible heat store such as a small DHW cylinder.

[0012] Because the specific reconfigurable fluid network includes a heat pump unit and is connected to a heat transfer device, at least one emitter, and a first heat exchanger, and because the first heat exchanger is external to the heat pump unit, a simplified, flexible system is obtained that can be operated in a number of specific modes, including a mode for providing domestic hot water and a mode for heating at least one space. Preferably, the multiple modes also include a mode for both cooling at least one space and providing domestic hot water (i.e., a mode in which at least one space is cooled and domestic hot water is provided), and heat removed from the at least one space is used to heat the domestic hot water.

[0013] The plurality of modes includes a (first) mode for providing domestic hot water and at least one (second) mode for heating at least one space, wherein in the at least one (first) mode for providing domestic hot water, the reconfigurable fluid network is configured to be in the first configuration, and in the (second) mode for heating at least one space, the reconfigurable fluid network is configured to be in the second configuration.

[0014] Due to the presence of a specific reconfigurable fluid network and a first heat exchanger external to the heat pump unit, a flexible system is obtained that can use a packaged heat pump (i.e., an integrated heat pump) or a split heat pump and can be used in several modes.

[0015] The first heat exchanger for transferring heat between the first heat transfer fluid and the second heat transfer fluid may also be referred to as a first external heat exchanger.

[0016] The second heat exchanger for preheating mains water to be further heated by the heat transfer device to obtain domestic hot water may also be called a second external heat exchanger.

[0017] The heat pump unit can include a complete heat pump, including a compressor, a first heat pump heat exchanger, at least one expansion valve, and a second heat pump heat exchanger, or the heat pump unit can be a heat pump subunit that includes only a portion of a heat pump (e.g., a compressor and at least one expansion valve, but no heat exchangers). When the heat pump unit is a heat pump subunit that does not include any heat exchangers, a system heat exchanger located external to the heat pump unit can act as the evaporator and condenser of the heat pump, providing a system similar to a split air conditioning system (i.e., a conventional air-to-air air conditioning system), where an outdoor unit (of a conventional air-to-air air conditioning system) supplies refrigerant to a (e.g., wall-mounted) heating and air conditioning unit that can act as an evaporator during cooling mode and a condenser during heating mode. Such a heat exchanger of the system located external to the heat pump unit may be, for example, a heat exchanger for transferring heat between a first heat transfer fluid and a second heat transfer fluid, at least one emitter, and / or a heat exchanger of a heat transfer device.

[0018] The piping of the reconfigurable fluid network can include piping external to the heat pump unit and piping internal to the heat pump unit. The piping internal to the heat pump unit can also be referred to as the (internal) piping of the heat pump unit. The piping external to the heat pump unit can also be referred to as the distribution circuit.

[0019] A preferred embodiment of the system according to the invention is characterized in that the heat pump unit is a water source heat pump unit.

[0020] A further preferred embodiment of the system according to the invention is characterized in that the first heat transfer fluid comprises water or comprises a refrigerant different from water, or consists of water or consists of a refrigerant different from water.

[0021] Further preferred embodiments of the system according to the invention are characterized in that the heat transfer device is a (third) heat exchanger, or the heat transfer device is a thermal energy storage device, preferably having a domestic hot water storage capacity of 50 L or less, more preferably 5-20 L, preferably containing a phase change material, more preferably having a domestic hot water storage capacity of 50 L or less, preferably 5-20 L, and / or allowing simultaneous charging (of the thermal energy storage device from the first hot fluid stream) and discharging (to a second cold fluid stream completely separated from the first hot fluid stream) of the thermal energy storage device. The use of a phase change material allows the system to have a higher energy storage density, which further reduces the system dimensions. The (third) heat exchanger that could be used as a heat transfer device can also be called a third external heat exchanger.

[0022] A further preferred embodiment of the system according to the invention is characterized in that when the heat transfer device is a thermal energy storage device, the system further comprises a state-of-fill analyzer for determining the state-of-fill of the thermal energy storage device, and preferably the controller is configured to operate the system taking into account the state-of-fill of the thermal energy storage device determined by the state-of-fill analyzer.

[0023] A further preferred embodiment of the system according to the invention is characterized in that the second heat transfer fluid comprises water, preferably comprises water from a heat network, more preferably comprises water from a district heat network (or is water, preferably is water from a heat network, more preferably is water from a district heat network). The district heat network is preferably a low temperature heat network, more preferably a low temperature heat network with a supply temperature of at least 20°C, even more preferably at least 30°C, most preferably at least 40°C.

[0024] A further preferred embodiment of the system according to the invention is characterized in that the first heat exchanger and / or the second heat exchanger are connected to a thermal network comprising a heat transfer fluid circuit (through which the second heat transfer fluid flows), the thermal network being preferably a low-temperature thermal network, more preferably a low-temperature thermal network with a supply temperature of at least 20°C, even more preferably at least 30°C, most preferably at least 40°C.

[0025] A further preferred embodiment of the system according to the invention is characterized in that the plurality of configurations further includes a further configuration in which the reconfigurable fluid network is configured to transport the first heat transfer fluid from the thermal network to the at least one emitter instead of to the heat pump unit, and the plurality of modes further includes a mode for heating at least one space by directly transporting thermal energy from the thermal network to the at least one emitter while bypassing the heat pump unit to save power, and in which mode the reconfigurable fluid network is configured to be in the further configuration.

[0026] A further preferred embodiment of the system according to the invention is characterized in that the system comprises at the domestic hot water outlet of the heat transfer device: - electric booster heaters, and / or - Adjustable valve for regulating the flow rate and / or temperature of domestic hot water It is characterized by further comprising:

[0027] An electric booster heater and / or an adjustable valve can be used to ensure a desired domestic hot water outlet temperature, for example the adjustable valve can adjust the domestic hot water flow rate to meet a domestic hot water set point, preferably between 40 and 50°C, for example 45°C.

[0028] A further preferred embodiment of the system according to the invention is characterized in that at least one valve is at least one three-way valve and / or at least one valve is switchable by a controller (to change the configuration of the reconfigurable fluid network).

[0029] A further preferred embodiment of the system according to the invention is characterized in that the reconfigurable fluid network comprises at least one pump, preferably at least two pumps, and / or the at least one valve comprises at least two valves, preferably at least four valves, preferably three-way valves and / or switchable by a controller (to change the configuration of the reconfigurable fluid network).

[0030] A further preferred embodiment of the system according to the invention is also capable of cooling at least one space, wherein: the heat pump unit is a reversible heat pump unit, and / or - the plurality of configurations further includes a third configuration in which the reconfigurable fluid network is configured to transport the first heat transfer fluid from the heat pump unit to the at least one emitter and from the heat pump unit to the heat transfer device, and the plurality of modes further includes a mode for cooling at least one space and providing domestic hot water, and the reconfigurable fluid network is configured to be in the third configuration.

[0031] In a third configuration, the reconfigurable fluid network is configured to transport (to and from) the first heat transfer fluid from (the low pressure side of) the heat pump unit to at least one emitter, and also to transport (to and from) the first heat transfer fluid from (the high pressure side of) the heat pump unit to the heat transfer device. To achieve the third configuration, the piping of the reconfigurable fluid network external to the heat pump unit can be connected (or be connected) to both sides of the heat pump unit (i.e., the high pressure and low pressure sides of the heat pump unit), for example to heat pump heat exchangers used as an evaporator and condenser, or to the heat pump unit's internal piping on both sides of the heat pump unit.

[0032] In a mode for cooling at least one space and providing domestic hot water, the reconfigurable fluid network is configured to a third configuration in which the reconfigurable fluid network is configured to transfer the first heat transfer fluid from the heat pump unit to the at least one emitter and from the heat pump unit to the first thermal energy storage device, so that the (thermal) energy (or heat) obtained by cooling the at least one space can be used to heat the heat transfer device and thus provide domestic hot water, rather than wasting the heat to the ambient air through the air heat exchanger, thereby providing domestic hot water energy efficiently without wasting the heat obtained by space cooling. Thus, the system according to the present invention is an energy-efficient system for providing domestic hot water, heating at least one space, and cooling the at least one space.

[0033] For example, a reversible heat pump can be obtained by the heat pump unit including a four-way valve arranged to allow the heat pump cycle to be reversed.

[0034] A further preferred embodiment of the system according to the invention is characterized in that the heat pump unit an internal refrigerant circuit for circulating a third heat transfer fluid, the internal refrigerant circuit comprising a compressor, a first heat pump heat exchanger, at least one expansion valve and a second heat pump heat exchanger, at least one of the first heat pump heat exchanger and the second heat pump heat exchanger being connected to piping of a reconfigurable fluid network external to the heat pump unit, preferably the first heat pump heat exchanger and the second heat pump heat exchanger each being connected to piping of a reconfigurable fluid network external to the heat pump unit, or - (a heat pump subunit) characterized in that it includes internal piping for transporting a first heat transfer fluid to and from the compressor and for transporting the first heat transfer fluid to and from the at least one expansion valve.

[0035] When the heat pump is a heat pump subunit, the heat pump subunit includes only a portion of the heat pump (e.g., a compressor and at least one expansion valve, but no heat exchanger). When the heat pump unit is a heat pump subunit that does not include any heat exchangers, a heat exchanger in a system located external to the heat pump unit can act as the evaporator and condenser of the heat pump, providing a system similar to a split air conditioning system (i.e., a conventional air-to-air air conditioning system) in which an outdoor unit (of a conventional air-to-air air conditioning system) supplies refrigerant to a (e.g., wall-mounted) heating and air conditioning unit that can act as an evaporator during a cooling mode and a condenser during a heating mode. Such a heat exchanger in a system located external to the heat pump unit can be, for example, a heat exchanger for transferring heat between a first heat transfer fluid and a second heat transfer fluid, at least one emitter, and / or a heat exchanger of a heat transfer device.

[0036] If the heat pump unit is a heat pump sub-unit and / or includes internal piping for transporting a first heat transfer fluid to and from the compressor and for transporting the first heat transfer fluid to and from at least one expansion valve, it is preferred that the first heat transfer fluid is a refrigerant other than water.

[0037] If the heat pump unit includes an internal refrigerant circuit for circulating a third heat transfer fluid, it is preferred that the first heat transfer fluid is water and / or that the third heat transfer fluid is a refrigerant different from water.

[0038] Preferably, the third heat transfer fluid (especially if a gas-liquid phase change is intended) is a refrigerant other than water.

[0039] A further preferred embodiment of the system according to the invention is characterized in that the system further comprises a further heat transfer device which is a solar heat transfer device, which is connected to the reconfigurable fluid network and preferably comprises at least one solar thermal collector and / or at least one PVT hybrid solar collector.

[0040] A further preferred embodiment of the system according to the invention is characterized in that the system further comprises an additional thermal energy storage device, which is connected to the reconfigurable fluid network and preferably comprises a phase change material. By using a phase change material in the additional thermal energy storage device, the system has a higher energy storage density, which further reduces the system dimensions.

[0041] A further preferred embodiment of the system according to the invention is characterized in that at least one emitter for heating or cooling at least one space comprises: - Fan coil units (FCUs), and / or - Wall-mounted HVAC (heating, ventilation, and air conditioning) units and / or ceiling cassettes, and / or - Underfloor heating The present invention is characterized in that it includes:

[0042] In systems featuring at least two heated space applications and / or dedicated heating applications, underfloor heating may also be advantageous. Underfloor heating is one of the most efficient radiator systems, but using underfloor heating for space cooling can result in uncomfortably cold feet. Thus, if there are at least two heated spaces, at least one space can be equipped with an FCU for heating and cooling, while at least one other space can be equipped with underfloor heating for space heating, which offers high efficiency and low fan noise.

[0043] A further preferred embodiment of the system according to the invention is characterized in that the heat transfer device, the reconfigurable fluid network (and therefore also the heat pump unit), the first heat exchanger and the second heat exchanger are arranged in one indoor unit.

[0044] The present invention also relates to a method for operating a system according to the present invention, wherein the controller operates the system at least in a mode for providing domestic hot water and / or in a mode for heating at least one space.

[0045] A further preferred embodiment of the method according to the invention is characterized in that the controller additionally operates the system in a mode for cooling at least one space, preferably in a mode for cooling at least one space and providing domestic hot water.

[0046] A further preferred embodiment of the method according to the invention is characterized in that the controller additionally operates the system in a mode for heating at least one space by transferring thermal energy directly from the thermal network to the at least one emitter while bypassing the heat pump unit to save power. Preferably, the first heat exchanger and / or the second heat exchanger are connected to a thermal network comprising a heat transfer fluid circuit (through which a second heat transfer fluid flows), the thermal network being more preferably a low-temperature thermal network, even more preferably a low-temperature thermal network with a supply temperature of at least 20°C, even more preferably at least 30°C, most preferably at least 40°C.

[0047] The preferred embodiments of the system described above apply correspondingly to the method according to the invention. [Brief explanation of the drawings]

[0048] [Figure 1] 1 shows a schematic diagram of a first embodiment (Example 1) of a system according to the invention. [Figure 2] 1 shows an exemplary arrangement of components. [Figure 3] 1 shows a control strategy for the system according to Example 1. [Figure 4] 1 shows a schematic diagram of mode DHW-1 of the system according to Example 1. [Figure 5] 1 shows a schematic diagram of mode DHW-2 of the system according to Example 1. [Figure 6a] FIG. 1 is a diagram showing the dependence of the system capacity on the desired DHW flow rate. [Figure 6b] FIG. 1 is a diagram showing the dependence of the system capacity on the desired DHW flow rate. DETAILED DESCRIPTION OF THE INVENTION

[0049] The present invention will now be described in more detail with reference to the following figures and examples, without being limited to the specific embodiments and parameters shown therein. [Example]

[0050] Figure 1 shows a schematic diagram of a first embodiment (Example 1) of a system according to the present invention. The system includes a heat transfer device 19 for providing domestic hot water, a radiator 14 for heating (and optionally cooling) at least one space, a reconfigurable fluid network for transporting a first heat transfer fluid, a first heat exchanger 15, a second heat exchanger 21, and a controller (not shown in Figure 1). In this example, the first heat transfer fluid is water.

[0051] The reconfigurable fluid network includes a heat pump unit 1, two pumps 8 and 9, four three-way valves, and piping. The heat pump unit 1 is a water-to-water heat pump unit including a (complete) water-to-water heat pump. The heat pump unit 1 includes an internal refrigerant circuit that circulates a third heat transfer fluid. The internal refrigerant circuit includes a first heat pump heat exchanger 2, two expansion valves 3a and 3b, a refrigerant receiver 4, a second heat pump heat exchanger 5, a four-way valve 6, and a compressor 7. The first heat pump heat exchanger 2 and the second heat pump heat exchanger 5 are each connected to piping of a reconfigurable fluid network outside the heat pump unit 1. The third heat transfer fluid is a refrigerant other than water.

[0052] The expansion valve is, for example, a linear expansion valve. The compressor is preferably of the hermetic scroll or reciprocating type. The first heat pump heat exchanger 2 and the second heat pump heat exchanger 5 are preferably plate heat exchangers for reasons of high efficiency and compactness.

[0053] The first heat exchanger 15 is a heat exchanger for transferring heat between a first heat transfer fluid and a second heat transfer fluid that is external to the reconfigurable fluid network, and the first heat exchanger 15 is external to the heat pump unit 1. In this embodiment, the second heat transfer fluid comprises (or is) water (e.g., from a district heat network).

[0054] The second heat exchanger 21 is a heat exchanger for preheating mains water to be further heated by the heat transfer device 19 to obtain domestic hot water.

[0055] The first heat exchanger 15 and / or the second heat exchanger 21 are connected via the same refrigerant circuit to a low temperature heat network 20 (e.g. a district heat network), which has a supply temperature of at least 20°C, preferably at least 30°C, more preferably at least 40°C.

[0056] The heat transfer device 19 is a compact thermal energy storage device (DHW-TES) or a heat exchanger having a storage capacity of 50 L or less. When the heat transfer device 19 is a compact thermal energy storage device, the compact thermal energy storage device preferably includes a phase change material (PCM) as an energy storage means. When the heat transfer device 19 is a compact thermal energy storage device, the compact thermal energy storage device can be coupled to a state of charge (SOC) analyzer (not shown in FIG. 1 ) configured to determine the state of charge of the first thermal energy storage device.

[0057] Furthermore, the system according to Example 1 allows to directly use the thermal energy from the thermal network for space heating while bypassing the heat pump unit to save electricity. The radiator 14 can be directly connected to the first heat exchanger 15 through the reconfigurable fluid network and the pump 8.

[0058] A portion of the system according to Example 1 is contained within a compact indoor unit. Specifically, the compact indoor unit includes a reconfigurable fluid network with a heat pump unit, a heat transfer device, and first and second heat exchangers. Figure 2 shows an exemplary arrangement of the components. According to this exemplary arrangement, the heat transfer device, which in this case is a compact thermal energy storage device (DHW-TES) with a storage capacity of 50 L or less, is located at the bottom of the indoor unit, and the first and second heat exchangers (HEX) are located adjacent to each other at the top of the indoor unit. Furthermore, a reconfigurable fluid network with a heat pump unit including a water-to-water heat pump is positioned in the middle of the indoor unit, i.e., between the heat transfer device and the two heat exchangers.

[0059] The controller of the system according to Example 1 is configured to operate the system in multiple modes (operation modes), and the reconfigurable fluid network can be configured into multiple configurations by the controller. Four three-way valves can be switched by the controller to change the configuration of the reconfigurable fluid network.

[0060] 3, 4, and 5 show a schematic diagram of the control strategy of the system according to Example 1 and the two operating modes DHW-1 and DHW-2. In this example, the heat transfer device 19 is a small thermal energy storage device (DHW-TES) with a domestic hot water discharge capacity of 50 L or less. FIG. 3 shows the control strategy. In FIG. 3, "Y" means "Yes," "N" means "No," "SOC" is the state of charge of the DHW-TES, "SOC-threshold" is the state of charge threshold of the DHW-TES, "T-HEX2" is the temperature of the first heat pump heat exchanger 2, and "T-Threshold" is the temperature threshold of the first heat pump heat exchanger 2. Furthermore, "Is charging?" refers to the current charging behavior of the DHW-TES, which was in mode DHW-2 in the previous loop iteration.

[0061] FIG. 4 shows a schematic diagram of mode DHW-1 of the system according to Example 1. In mode DHW-1, the state of charge of the DHW-TES falls below the SOC threshold. The SOC threshold can be in the range of 40-90%, but is preferably in the range of 40-70%. The heat pump unit is turned on, and the internal refrigerant circuit of the heat pump unit 1 is preheated until the temperature in the first heat pump heat exchanger 2 reaches the threshold temperature. The system then switches to mode DHW-2. In mode DHW-1, it may be beneficial to bypass the radiator in the radiator circuit. This bypass would allow the internal refrigerant circuit of the heat pump unit 1 to heat up faster and reach the temperature threshold in a shorter time.

[0062] Figure 5 shows a schematic diagram of mode DHW-2 of the system according to Example 1. In mode DHW-2, the heat pump charges the DHW-TES and / or heats the mains water to the desired domestic hot water outlet temperature.

[0063] The system's capabilities are Q HP =V w ρ w c p,w (T dhw -Tpm ) This depends on the desired DHW flow rate and preheat mains water temperature. Here, V w is the DHW flow rate, ρ w is the density of water, c p,w is the specific heat capacity of water, and T dhw is the DHW outlet temperature, i.e., 45°C in this example, T pm is the preheat main water temperature. In this example, the heat pump HP = 8 kW. The diagrams shown in Figures 6a and 6b also reveal the dependence of the system capacity on the desired DHW flow rate.

[0064] The diagrams in Figures 6a and 6b show the following: a) To achieve a DHW temperature of 45°C, the heat pump capacity depends on the DHW flow rate and the preheat mains water temperature. For example, to heat water to 45°C at the DHW outlet, if the DHW flow rate is 6 L / min, the preheat mains water temperature would have to be at least 26°C. In addition, the plot shows that to deliver DHW at 45°C at 8 L / min, without a preheat HEX, a 20 kW heat pump would be required. b) Heat source temperature requirement to achieve a DHW outlet temperature of 45°C, assuming 85% heat exchanger effectiveness in the preheating heat exchanger. This analysis shows that a heat source temperature of approximately 35°C would be required to achieve an outlet temperature of 45°C using an 8kW heat pump delivering 8 L / min without a storage tank.

[0065] For heat networks providing temperatures below 30°C, the system could be modified by the following measures to meet the DHW temperature requirements: - Increase the dimensions of the DHW-TES. - The DHW flow rate is adjusted by a proportional valve at the DHW outlet to meet the DHW set point, e.g. 45°C, according to the formula shown above. - An electric booster heater at the DHW outlet increases the temperature to the desired DHW set point, e.g. 45°C. A booster heater may be useful if no DHW-TES is present or to reduce the size of the DHW-TES even further.

[0066] Various aspects of the present disclosure are summarized below as appendices.

[0067] (Appendix 1) 1. A system for heating at least one space and providing domestic hot water, comprising: a heat transfer device (19) for providing domestic hot water; at least one emitter (14) provided within said at least one space for heating said at least one space; a reconfigurable fluid network for transporting a first heat transfer fluid, the reconfigurable fluid network including a heat pump unit (1), at least one valve, and piping, the heat pump unit (1) including a compressor (7) and at least one expansion valve (3a, 3b), the reconfigurable fluid network being configurable by a controller into a plurality of configurations, the configurations including a first configuration in which the reconfigurable fluid network is configured to transport the first heat transfer fluid from the heat pump unit (1) to the heat transfer device (19) but not to the at least one emitter (14), and a second configuration in which the reconfigurable fluid network is configured to transport the first heat transfer fluid from the heat pump unit (1) to the at least one emitter (14) but not to the heat transfer device (19); a first heat exchanger (15) for transferring heat between the first heat transfer fluid and a second heat transfer fluid external to the reconfigurable fluid network, the first heat exchanger being external to the heat pump unit (1); a second heat exchanger (21) for preheating mains water to be further heated by the heat transfer device (19) to obtain domestic hot water; the controller configured to operate the system in a plurality of modes, the plurality of modes including a mode for providing domestic hot water, in which the reconfigurable fluid network is configured in the first configuration, and a mode for heating the at least one space, in which the reconfigurable fluid network is configured in the second configuration; A system including: (Appendix 2) 2. The system according to claim 1, wherein the heat pump unit (1) is a water source heat pump unit. (Appendix 3) 3. The system of claim 1 or 2, wherein the first heat transfer fluid comprises water, comprises a refrigerant other than water, consists of water, or consists of a refrigerant other than water. (Appendix 4) 4. The system according to any one of claims 1 to 3, wherein the heat transfer device (19) is a heat exchanger, or the heat transfer device is a thermal energy storage device, preferably comprising a phase change material, and / or allowing simultaneous charging and discharging of the thermal energy storage device. (Appendix 5) 5. The system according to any one of claims 1 to 4, wherein when the heat transfer device (19) is the thermal energy storage device, the system further comprises a state-of-fill analyzer for determining a state-of-fill of the thermal energy storage device (19), preferably wherein the controller is configured to operate the system taking into account the state-of-fill of the thermal energy storage device (19) determined by the state-of-fill analyzer. (Appendix 6) 6. A system according to any one of claims 1 to 5, wherein the second heat transfer fluid comprises water, preferably water from a heat network, more preferably water from a district heat network. (Appendix 7) 7. A system according to any one of claims 1 to 6, wherein the first heat exchanger (15) and / or the second heat exchanger (21) are connected to a thermal network comprising a heat transfer fluid circuit, the thermal network being preferably a low-temperature thermal network (20), more preferably a low-temperature thermal network (20) having a supply temperature of at least 20°C, even more preferably at least 30°C, and most preferably at least 40°C. (Appendix 8) 8. The system of claim 7, wherein the plurality of configurations further includes a further configuration in which the reconfigurable fluid network is configured to transport the first heat transfer fluid from the thermal network to the at least one emitter (14) instead of to the heat pump unit (1), and the plurality of modes further includes a mode for heating the at least one space by transferring thermal energy directly from the thermal network to the at least one emitter while bypassing the heat pump unit to save power, in which mode the reconfigurable fluid network is configured to be the further configuration. (Appendix 9) The system according to any one of Supplementary Notes 1 to 8, further comprising: - electric booster heaters, and / or - Valves for regulating the flow rate and / or temperature of domestic hot water The system further comprising: (Appendix 10) 10. The system according to any one of claims 1 to 9, wherein the reconfigurable fluid network comprises at least one pump (8, 9), preferably at least two pumps (8, 9), and / or the at least one valve comprises at least two valves, preferably at least four valves. (Appendix 11) 11. The system of any one of claims 1 to 10, wherein the system is also capable of cooling the at least one space, wherein: - the heat pump unit (1) is a reversible heat pump unit, and / or the plurality of configurations further includes a third configuration in which the reconfigurable fluid network is configured to transport the first heat transfer fluid from the heat pump unit (1) to the at least one emitter (14) and from the heat pump unit (1) to the heat transfer device (19), and the plurality of modes further includes a mode for cooling the at least one space and providing domestic hot water, and the reconfigurable fluid network is configured to be in the third configuration. A system characterized by: (Appendix 12) The system according to any one of Supplementary Notes 1 to 11, wherein the heat pump unit (1) an internal refrigerant circuit for circulating a third heat transfer fluid, the internal refrigerant circuit comprising the compressor (7), a first heat pump heat exchanger (2), the at least one expansion valve (3a, 3b) and a second heat pump heat exchanger (5), at least one of the first heat pump heat exchanger (2) and the second heat pump heat exchanger (5) being connected to piping of the reconfigurable fluid network external to the heat pump unit (1), preferably the first heat pump heat exchanger (2) and the second heat pump heat exchanger (5) each being connected to piping of the reconfigurable fluid network external to the heat pump unit, or - internal piping for transporting said first heat transfer fluid to and from said compressor (7) and for transporting said first heat transfer fluid to and from said at least one expansion valve (3a, 3b); A system characterized by: (Appendix 13) 13. A method for operating a system according to any one of claims 1 to 12, wherein the controller operates the system in at least a mode for providing domestic hot water and / or a mode for heating the at least one space. (Appendix 14) 14. The method of claim 13, wherein the controller additionally operates the system in a mode for cooling the at least one space, preferably in a mode for cooling the at least one space and providing domestic hot water. (Appendix 15) 15. The method of claim 13 or 14, wherein the controller additionally operates the system in a mode for heating the at least one space by transferring thermal energy directly from a thermal network to the at least one emitter while bypassing the heat pump unit to save power. [Explanation of symbols]

[0068] 1 heat pump unit 2. First heat pump heat exchanger 3a, 3b Expansion valve 4 Refrigerant receiver 5. Second heat pump heat exchanger 6 Four-way valve 7 Compressor 8, 9 Pump 14 Heatsink 15 1st heat exchanger 19 Heat Transfer Devices 20 Low-Temperature Heat Network 21 Second heat exchanger

Claims

1. 1. A system for heating at least one space and providing domestic hot water, comprising: a heat transfer device for providing domestic hot water; at least one emitter provided within said at least one space for heating said at least one space; a reconfigurable fluid network for transporting a first heat transfer fluid, the reconfigurable fluid network including a heat pump unit, at least one valve, and piping, the heat pump unit including a compressor and at least one expansion valve, the reconfigurable fluid network being configurable by a controller into a plurality of configurations including a first configuration in which the reconfigurable fluid network is configured to transport the first heat transfer fluid from the heat pump unit to the heat transfer device but not to the at least one emitter, and a second configuration in which the reconfigurable fluid network is configured to transport the first heat transfer fluid from the heat pump unit to the at least one emitter but not to the heat transfer device; a first heat exchanger for transferring heat between the first heat transfer fluid and a second heat transfer fluid external to the reconfigurable fluid network, the first heat exchanger being external to the heat pump unit; a second heat exchanger for preheating mains water to be further heated by said heat transfer device to obtain domestic hot water; the controller configured to operate the system in a plurality of modes, the plurality of modes including a mode for providing domestic hot water, in which the reconfigurable fluid network is configured in the first configuration, and a mode for heating the at least one space, in which the reconfigurable fluid network is configured in the second configuration; A system including:

2. 10. The system of claim 1, wherein the heat pump unit is a water source heat pump unit.

3. 3. A system according to claim 1 or 2, characterized in that the first heat transfer fluid comprises water or comprises a refrigerant different from water, or consists of water or consists of a refrigerant different from water.

4. 3. A system according to claim 1 or 2, characterized in that the heat transfer device is a heat exchanger, or the heat transfer device is a thermal energy storage device, preferably comprising a phase change material, and / or allowing simultaneous charging and discharging of the thermal energy storage device.

5. 3. The system according to claim 1 or 2, wherein when the heat transfer device is the thermal energy storage device, the system further comprises a state-of-fill analyzer for determining a state-of-fill of the thermal energy storage device, preferably wherein the controller is configured to operate the system taking into account the state-of-fill of the thermal energy storage device determined by the state-of-fill analyzer.

6. 3. A system according to claim 1 or 2, characterized in that the second heat transfer fluid comprises water, preferably water from a heat network, more preferably water from a district heat network.

7. 3. A system according to claim 1 or 2, characterized in that the first heat exchanger and / or the second heat exchanger are connected to a thermal network including a heat transfer fluid circuit, the thermal network being preferably a low-temperature thermal network, more preferably a low-temperature thermal network with a supply temperature of at least 20°C, even more preferably at least 30°C, most preferably at least 40°C.

8. 8. The system of claim 7, wherein the plurality of configurations further includes a further configuration in which the reconfigurable fluid network is configured to transport the first heat transfer fluid from the thermal network to the at least one emitter instead of to the heat pump unit, and the plurality of modes further includes a mode for heating the at least one space by transferring thermal energy directly from the thermal network to the at least one emitter while bypassing the heat pump unit to save power, in which mode the reconfigurable fluid network is configured to be the further configuration.

9. 3. The system according to claim 1 or 2, further comprising: - electric booster heaters, and / or - Valves for regulating the flow rate and / or temperature of domestic hot water The system further comprising:

10. 3. A system according to claim 1 or 2, characterized in that the reconfigurable fluid network comprises at least one pump, preferably at least two pumps, and / or the at least one valve comprises at least two valves, preferably at least four valves.

11. 3. The system of claim 1 or 2, wherein the system is also capable of cooling the at least one space, wherein: - the heat pump unit is a reversible heat pump unit, and / or the plurality of configurations further includes a third configuration in which the reconfigurable fluid network is configured to transport the first heat transfer fluid from the heat pump unit to the at least one emitter and from the heat pump unit to the heat transfer device, the plurality of modes further including a mode for cooling the at least one space and providing domestic hot water, and the reconfigurable fluid network is configured to be in the third configuration. A system characterized by:

12. 3. The system of claim 1 or 2, wherein the heat pump unit: an internal refrigerant circuit for circulating a third heat transfer fluid, the internal refrigerant circuit comprising the compressor, a first heat pump heat exchanger, the at least one expansion valve and a second heat pump heat exchanger, at least one of the first heat pump heat exchanger and the second heat pump heat exchanger being connected to piping of the reconfigurable fluid network external to the heat pump unit, preferably the first heat pump heat exchanger and the second heat pump heat exchanger each being connected to piping of the reconfigurable fluid network external to the heat pump unit, or - internal piping for transporting said first heat transfer fluid to and from said compressor and for transporting said first heat transfer fluid to and from said at least one expansion valve; A system characterized by:

13. 3. A method for operating a system as claimed in claim 1 or 2, wherein the controller operates the system in at least a mode for providing domestic hot water and / or a mode for heating the at least one space.

14. 14. The method of claim 13, wherein the controller additionally operates the system in a mode for cooling the at least one space, preferably in a mode for cooling the at least one space and providing domestic hot water.

15. 14. The method of claim 13, wherein the controller additionally operates the system in a mode for heating the at least one space by transferring thermal energy directly from a thermal network to the at least one emitter while bypassing the heat pump unit to save power.

Images