Improved heat pump system and method thereof

Abstract

The invention relates to a heat pump system (1) with a refrigerant circuit (3) comprising a compressor (5), a first heat exchanger (11) and a second heat exchanger (19), each of which can be operated as a gas cooler / condenser, an expansion element (17, 21, 23), a chiller (25) and a fourth heat exchanger (13) which can be operated as an evaporator in a parallel arrangement with the chiller (25), wherein in heat pump operation the first heat exchanger (11) is arranged upstream of the second heat exchanger (19) in the refrigerant flow direction and is also connected to a first liquid circuit (27) for heat transfer from the refrigerant to a first heat transfer fluid, and the chiller (25) is also connected to a liquid line (53) for heat transfer from a heat storage medium (49) for the refrigerant to absorb heat from a second heat transfer fluid.wherein the second heat exchanger (19) for switchable heat transfer from the refrigerant to the heat storage (49) is connected to a second liquid circuit (45), and the refrigerant circuit (3) is designed to be switchable such that, in heat pump operation, when such heat transfer is activated in the second heat exchanger (19), the fourth heat exchanger (13) can be used as an evaporator by the refrigerant instead of the chiller (25). Furthermore, the invention relates to a method for operating the heat pump system, such as for space heating in a building.

Description

Field of technology:

[0001] The invention relates to a heat pump system according to the preamble of claim 1. Such heat pump systems are primarily used for space heating in buildings or vehicles. The refrigerant circuit comprises a compressor, at least two heat exchangers operable as gas coolers / condensers, at least one expansion element, and at least one chiller configured as a liquid-refrigerant heat exchanger, as well as at least one heat exchanger operable as an evaporator in parallel with the chiller, connected in circuit by refrigerant lines.

[0002] Heat is extracted from the warm refrigerant compressed in the compressor during operation in at least one gas cooler / condenser and then expanded in the expansion device, where it cools down and then absorbs heat in the chiller or in the heat exchanger arranged in parallel with it before it reaches the compressor inlet.

[0003] Furthermore, the invention relates to a method for operating such a heat pump system. State of the art:

[0004] Heat pump systems are known in which the heat source is ambient air alone. The efficiency of these heat pump systems decreases at very low ambient air temperatures. While heat pump systems that use geothermal energy, district heating, or heat stored in a heat storage unit do not suffer from this disadvantage to the same extent, there are also ranges of ambient air temperatures that can offer better conditions for heat pump heating. DE102019135468 and EP3531042A1 B1 disclose heat pump systems that optionally use ambient air as a heat source and heat supplied by a heat transfer fluid, for example, geothermal energy, district heating, solar heat, or stored heat. The heat pump systems therein have a heat storage unit from which heat can be transferred to the refrigerant during heat pump operation, i.e., during heating operation.Charging these heat storage units with heat from the refrigerant in the refrigerant circuit is only possible in DE102019135468 and EP3531042A1 B1 during cooling operation of the heat pump system. Figure 4 Although the heat pump system disclosed in DE102010051976 A1 has two liquid-refrigerant heat exchangers arranged one after the other as gas cooler / condenser in the refrigerant circuit, a heat accumulator that can be loaded with heat for supplying heat to a chiller is not disclosed therein.

[0005] The heat pump system for a building disclosed in DE102017006550 A1 comprises two liquid-refrigerant heat exchangers arranged in parallel as condensers in the refrigerant circuit. Two compressors are used to achieve mutually different temperature levels of the refrigerant flowing through these two heat exchangers. In the heat pump system disclosed in DE102021212312 A1, the internal condenser provided for heating the passenger compartment is designed as an air-refrigerant heat exchanger. DE202011003667 U1 discloses a water supply system with two buffer tanks.

[0006] The invention defined in claim 1 is therefore based on the problem that existing heat pump systems are inadequate, particularly with regard to their design and the flexibility of heat storage for utilizing stored heat for heat pump operation. The object is therefore to provide a heat pump system that is improved, particularly with regard to its design and the flexibility of heat storage for utilizing stored heat for heat pump operation.

[0007] A corresponding object is to provide an improved method for operating such a heat pump system. Summary of the invention:

[0008] The problem underlying the invention defined in claim 1 is solved by the features set out in claim 1. In that the heat pump system comprises a refrigerant circuit comprising a compressor, at least one first and one second heat exchanger, each designed as a liquid-refrigerant heat exchanger and operable as a gas cooler / condenser, at least one expansion element, at least one chiller designed as a liquid-refrigerant heat exchanger, and at least one fourth heat exchanger operable as an evaporator in parallel with the chiller, wherein in heat pump operation the first heat exchanger is arranged upstream of the second heat exchanger in the refrigerant flow direction and is used for heat transfer from a refrigerant of the refrigerant circuit to a first heat transfer fluid of a first fluid circuit, also to the first fluid circuit, which is preferably a heating circuit,is connected, and the chiller is also connected to a liquid line for heat transport from a heat source and / or a heat storage device for heat absorption of the refrigerant from a second heat transfer liquid, wherein the second heat exchanger is connected to a second liquid circuit for switchable heat transfer from the refrigerant to the heat storage device, and the refrigerant circuit is designed to be switchable such that in heat pump operation, when such heat transfer is switched on in the second heat exchanger, the fourth heat exchanger can be flowed through as an evaporator by the refrigerant instead of the chiller, the problem is solved.

[0009] The chiller is designed as a liquid-refrigerant heat exchanger for heat absorption of the refrigerant from a liquid.

[0010] A heat exchanger designed as a gas cooler / condenser can be a condenser for refrigerant to be operated subcritically in the high-pressure area of ​​the refrigerant circuit or a gas cooler for refrigerant to be operated supercritically in the high-pressure area of ​​the refrigerant circuit, or it can be designed in such a way that it can be used both as a gas cooler and as a condenser.

[0011] The heat pump system according to the invention has the advantage that the heat storage device can be loaded with heat released by the refrigerant even during heat pump operation. Heat can still be released to the first heat transfer fluid for heating and / or for domestic water heating by the refrigerant in the first heat exchanger, which is hotter than that in the second heat exchanger during heat pump operation. This increases the flexibility for loading the heat storage device. This makes it possible to use a heat storage device with a lower heat capacity than before, which saves space, material, and costs. If the temperature of the second heat transfer fluid is unfavorably low for use as a heat source during heat pump operation, it is possible to supply heat to the heat storage device during heat pump operation according to the invention in order to thus increase the temperature of the second heat transfer fluid.Furthermore, with the heat pump system according to the invention, the phases of heat pump operation can be advantageously extended by utilizing heat from the heat storage unit instead of from the ambient air, because the heat storage unit can be recharged in the fourth heat exchanger while the heat from the ambient air is being used. The heat pump system according to the invention requires only one compressor, which is primarily space- and material-saving and cost-effective. Particularly during heat pump operation, the first and second heat exchangers are arranged in series in the high-pressure area of ​​the refrigerant circuit, which ensures that the temperature of the warm refrigerant in the second heat exchanger is lower than that in the first heat exchanger during operation.

[0012] The subclaims specify advantageous embodiments, further developments and improvements of the respective subject matter of the invention.

[0013] Preferably, the second fluid circuit comprises at least one shutoff valve that can be switched to supply the fluid line for the second heat transfer fluid to the chiller, and the second fluid circuit is switchable such that the second heat transfer fluid can flow either through the chiller or through the second heat exchanger. As a result, the second heat transfer fluid can be used both for heat transfer from a heat source and / or the heat storage device to the coolant in the chiller and for heat transfer from the coolant in the second heat exchanger to the heat storage device, eliminating the need for two separate fluid circuits, each with a heat transfer fluid.

[0014] According to an advantageous development of the heat pump system, the first heat exchanger is also connected to an additional liquid line for heat transfer from the refrigerant to the domestic water. Alternatively, a fifth heat exchanger, designed as a liquid-refrigerant heat exchanger and operable as a gas cooler / condenser, is arranged upstream of the first heat exchanger in the refrigerant circuit in the direction of refrigerant flow. This fifth heat exchanger is designed as a liquid-refrigerant heat exchanger and can be operated as a gas cooler / condenser. This fifth heat exchanger is connected to the additional liquid line for heat transfer from the refrigerant to the domestic water. Thus, in addition to heating, the heat pump system can also be used for heating domestic water, which can be done either as an alternative to or simultaneously with heating.In heat pump operation of the heat pump system, the heating of domestic water is possible on the one hand alone and on the other hand together with the heating of the first heat transfer fluid in the first fluid circuit designed as a heating circuit.

[0015] Preferably, an additional liquid line is connected to the second heat exchanger or, if necessary, to an additional heat exchanger in the refrigerant circuit for heat transfer from the refrigerant to the domestic water. In one of the two alternatives, heat from the refrigerant can be advantageously transferred to the heat storage unit or to the domestic water in the second heat exchanger. A second heat exchanger, in which the refrigerant can transfer heat to two liquids, is a compact solution for two functions. In the other alternative, heat from the refrigerant can be transferred to the domestic water in the additional heat exchanger, if necessary.

[0016] According to an advantageous development, the heat pump system is designed such that it can also be operated in cooling mode, wherein the chiller or a possibly further chiller is connected for heat absorption of the refrigerant of the refrigerant circuit from either the first heat transfer fluid to the first fluid circuit, or a possibly third heat transfer fluid to a possibly third fluid circuit, which is preferably a cooling circuit, and the heat pump system is switchable for cooling mode such that the heat transfer in the first heat exchanger from the refrigerant to the first heat transfer fluid and the heat transfer in the chiller from the second heat transfer fluid to the refrigerant are switched off. As a result, the heat pump system can be operated not only in heat pump mode for heating and / or domestic hot water heating, but also in cooling mode as an air conditioning system.Furthermore, it is thus possible to heat domestic water in the first and / or second heat exchanger during cooling operation of the heat pump system as an air conditioning system. The fourth heat exchanger is preferably designed such that it can be operated as an evaporator during heat pump operation and as a gas cooler / condenser during cooling operation of the heat pump system, which saves material and space for an otherwise additional heat exchanger. The fourth heat exchanger is designed as an air-refrigerant heat exchanger and is intended for heat exchange of the refrigerant with ambient air or exhaust air. As a result, ambient air or exhaust air can be used as the heat source for heat pump operation. According to one embodiment, the fourth heat exchanger is an air-refrigerant heat exchanger which has separate refrigerant lines for operation as an evaporator and for operation as a gas cooler / condenser.

[0017] According to an advantageous embodiment, the heat pump system comprises at least one solar collector that can be thermally connected to the heat storage unit for heat transfer via a fluid circuit. Thus, heat from the solar collectors can be stored in the heat storage unit, which can be released to the coolant in the chiller when needed during heat pump operation.

[0018] According to an advantageous embodiment, the heat storage system comprises at least one ground loop containing a heat transfer fluid for geothermal energy. This allows geothermal energy to be effectively utilized and stored for heat pump operation. The heat transfer fluid simultaneously serves as a heat storage medium, which can also be charged with heat by the warm refrigerant in the second heat exchanger.

[0019] According to an advantageous embodiment, the heat storage device comprises a network with a heat transfer fluid. Such a network is preferably a district heating network or part thereof. Heat can be transferred from the refrigerant to the network via the second heat exchanger of the heat pump system.

[0020] The heat storage device preferably comprises a latent heat storage medium capable of storing latent heat. Such a heat storage medium has a particularly high heat storage capacity. For example, a heat storage device that can be used as an ice storage device and can be loaded with heat instead of ambient air as the heat source at ambient air temperatures below 0 °C is an option for a heat pump system in heat pump mode.

[0021] The heat pump system preferably comprises a control system designed to control shut-off valves and expansion elements of the refrigerant circuit and pumps and / or shut-off valves of the first and second liquid circuits at least in such a way that the two operating modes of operating the heat pump system in pure heat pump operation with heat release from the refrigerant for domestic water and / or for space heating and heat absorption of the refrigerant from the second heat transfer liquid in the chiller, or of operating the heat pump system in such a heat pump operation with heat release from the refrigerant for domestic water and / or for space heating, in which the heat absorption of the refrigerant in the fourth heat exchanger and simultaneously also heat release in the second heat exchanger from the refrigerant through the second liquid circuit to the heat storage device, can be set.This allows the heat pump system to be operated in heat pump mode in two operating modes: charging or not charging the heat storage tank with heat from the refrigerant. Such a heat pump system is advantageous, for example, during decreasing daytime temperatures, when heat pump operation allows the heat storage tank to continue to be charged with heat even when heating demand is low in the evening for use during cold nights.

[0022] Preferably, the control system is additionally configured such that the heat transfer in the second heat exchanger or, if applicable, in a further heat exchanger, from the refrigerant to the domestic water can be switched on and off, and the heat transfer in the first or, if applicable, fifth heat exchanger, from the refrigerant to the domestic water can be switched on and off. This allows heat to be supplied to the domestic water in a gradual manner as needed. For example, instead of to the heat storage, heat can be supplied from the refrigerant in the second heat exchanger or, if applicable, in a further heat exchanger, to the domestic water in a controlled manner.

[0023] According to an advantageous development, a heat pump system according to the invention that can also be operated in cooling mode comprises a control system configured such that, under its control, the heat pump system can be operated in cooling mode with the heat transfer from the refrigerant to the first heat transfer fluid in the first heat exchanger switched off and the heat absorption of the refrigerant from the first or, if applicable, third heat transfer fluid in the chiller or, if applicable, in the additional chiller switched on. This allows the heat pump system to be automatically operated via the control system in heat pump mode or cooling mode depending on the heating or cooling requirements, which represents a particularly flexible automatic control of the heat pump system.

[0024] Preferably, the control system is also designed such that the further two operating modes of operation in pure charging mode with only heat release in the second heat exchanger from the refrigerant through the second liquid circuit to the heat accumulator and simultaneous heat absorption of the refrigerant in the fourth heat exchanger, or in charging mode with cooling mode with heat release in the second heat exchanger from the refrigerant through the second liquid circuit to the heat accumulator and simultaneous heat absorption of the refrigerant in the chiller or in the optionally further chiller from the first or optionally third heat transfer fluid, can be set under its control. This allows charging of the heat accumulator with heat from the refrigerant to be automatically set with the control system in a particularly flexible manner for different operating modes of the heat pump system.

[0025] The control system of a heat pump system according to the invention is preferably designed such that, for selecting the operating mode of the heat pump system, it receives data from temperature sensors for the temperatures of domestic water, ambient air, room air, and the heat storage medium of the heat storage unit, as well as data relating to a weather forecast. For example, a weather forecast can be received from the internet. This data improves the control of the heat pump system with regard to a suitable operating mode.

[0026] According to an advantageous embodiment, the heat pump system according to the invention is provided and designed at least for space heating of a building. According to another advantageous embodiment, the heat pump system according to the invention is provided and designed for a vehicle, such as a rail vehicle or bus.

[0027] The object with regard to a method is achieved by a method for operating a heat pump system according to the invention with the method features of claim 13. In that, in the method, the refrigerant circuit and the first and second liquid circuits can be controlled in such a way that, at least partly depending on the charge state of the heat accumulator, the heat pump system can be operated in one of the at least three controllable operating modes of pure heat pump operation with heat release from the refrigerant for domestic water and / or for space heating and with heat absorption of the refrigerant from the second heat transfer fluid in the chiller, or heat pump operation with heat release from the refrigerant for domestic water and / or for space heating with heat absorption of the refrigerant in the fourth heat exchanger and, at the same time, heat release in the second heat exchanger from the refrigerant through the second liquid circuit to the heat accumulator,or pure heat pump operation with heat release of the refrigerant for domestic water and / or for space heating and with heat absorption of the refrigerant in the fourth heat exchanger, the problem is solved with regard to a process.

[0028] With regard to the advantages, advantageous embodiments, and further developments, the relevant above information regarding the heat pump system according to the invention applies accordingly. If no simultaneous heat transfer in the second heat exchanger from the refrigerant through the second liquid circuit to the heat storage device is selected, in the case of pure heat pump operation, the heat absorption of the refrigerant is adjusted in the chiller or in the fourth heat exchanger, depending on which heat source is currently more advantageous.

[0029] The method preferably comprises the steps of releasing heat for domestic water from the refrigerant in the first or, optionally, fifth heat exchanger, as needed. If heat is not released from the refrigerant to the heat storage device in the second heat exchanger, releasing heat for domestic water from the refrigerant in the second heat exchanger or, optionally, in the additional heat exchanger of the refrigerant circuit, as needed. Thus, domestic water is heated by the heat pump system in a specifically gradual manner, adapted to the demand.

[0030] According to an advantageous embodiment, depending on the cooling requirement, the method comprises the step of operating a heat pump system according to the invention that can be operated in cooling mode with heat transfer from the refrigerant to the first heat transfer fluid in the first heat exchanger switched off and heat absorption of the refrigerant from the first or, if applicable, third heat transfer fluid in the chiller or, if applicable, in the additional chiller switched on. This cooling mode as an additional operating mode increases the flexibility of operating the heat pump system.

[0031] The method preferably comprises the steps of controlling the refrigerant circuit and the first and second liquid circuits, and optionally the third liquid circuit, such that the heat pump system is operated in the selectable further operating modes of charging operation with cooling operation or pure charging operation with only heat dissipation in the second heat exchanger from the refrigerant through the second liquid circuit to the heat accumulator and simultaneous heat absorption from the refrigerant in the fourth heat exchanger or, during cooling operation, in the chiller or in the optionally further chiller from the first or optionally third heat transfer fluid. This allows for particularly flexible charging of the heat accumulator with heat from the refrigerant in different operating modes.

[0032] According to an advantageous embodiment, the method comprises the steps Receiving data from temperature sensors for temperatures of domestic water, ambient air, room air, and the heat storage medium of the heat storage unit, as well as with regard to a weather forecast; evaluating the received data to select an operating mode of the heat pump system according to the invention, taking efficiency requirements into account; then selecting an operating mode based on the result of the evaluation; and setting the selected operating mode of the heat pump system. This allows the heat pump system to be operated efficiently. For example, taking efficiency into account, a selection is made between the operating modes of heat pump operation in which the heat is supplied to the refrigerant either from the ambient air in the fourth heat exchanger or from the heat storage unit in the chiller via the second heat transfer fluid.For example, if the ambient air temperature is significantly lower than that in the heat storage tank, the more efficient operating mode with heat supplied to the refrigerant from the heat storage tank would be selected.

[0033] According to an advantageous embodiment, the method comprises the steps receiving data on the charge state of the heat storage device, such as in particular the temperature of the heat storage medium and / or the size of the latent heat stored in the heat storage medium, as well as receiving data on the temperature of ambient air and with regard to a weather forecast, and then creating a discharge forecast for the heat storage device using the received data, taking into account possible operating modes of the heat pump system according to the invention, and then selecting an operating mode of the heat pump system taking into account the created discharge forecast for the heat storage device, and finally setting the selected operating mode of the heat pump system.

[0034] This method for managing heat storage in the heat storage tank effectively accommodates heat pump operation, with the heat storage tank being charged with heat from the refrigerant flowing through the second heat exchanger. The operating mode in which the heat storage tank is charged or discharged with heat can be proactively selected, taking into account the weather forecast, particularly the ambient air temperature forecast.

[0035] According to an advantageous development, the method comprises the features that the received data regarding the weather forecast include data for an expected solar yield, and that the expected solar yield from a heat pump system according to the invention equipped with a solar collector is taken into account when creating the discharge forecast for the heat storage unit. This allows the heat that can be supplied from the solar collector to the heat storage unit to be particularly well integrated into the management of heat storage in the heat storage unit. Short description of the drawings:

[0036] Embodiments of the invention are explained with reference to the drawings.

[0037] It shows Fig. 1 a schematic representation of an embodiment of a heat pump system according to the invention; Fig. 2 that in Fig. 1 illustrated embodiment of a heat pump system in pure heat pump operation; Fig. 3 that in Fig. 1 illustrated embodiment of a heat pump system in heat pump operation and charging operation; Fig. 4 that in Fig. 1 illustrated embodiment of a heat pump system in further heat pump operation with domestic water heating; Fig. 5 that in Fig. 1 illustrated embodiment of a heat pump system in heat pump operation with defrost function; Fig. 6 that in Fig. 1 illustrated embodiment of a heat pump system in pure cooling mode; Fig. 7 that in Fig. 1illustrated embodiment of a heat pump system in cooling and charging mode; Fig. 8 that in Fig. 1 illustrated embodiment of a heat pump system in pure charging mode; Fig. 9 a schematic representation of a further embodiment of a heat pump system according to the invention; Fig. 10 a schematic representation of a further embodiment of a heat pump system according to the invention; Fig. 11 in schematic representation a further embodiment of a heat pump system according to the invention; and Fig. 12 as a flowchart an embodiment of a method for operating a heat pump system according to the invention. Detailed description of the invention:

[0038] All drawings are schematic. Scale drawings have been omitted for the sake of clarity.

[0039] In Figure 1An embodiment of a heat pump system 1 according to the invention is shown schematically. The refrigerant circuit 3 comprises a single compressor 5, in which the refrigerant is compressed during operation. In this case, the refrigerant is CO2, which is operated supercritically in the high-pressure region of the refrigerant circuit 3. Also conceivable are designs of the refrigerant circuit 3 in which the refrigerant is operated only subcritically, such as R1234yf.

[0040] In the refrigerant circuit 3, the refrigerant line, after leaving the compressor 5, divides into the first and second branches, which can be shut off with shut-off valves 7 and 9. The first branch contains the first heat exchanger 11, which can be operated as a gas cooler / condenser and is designed as a liquid-refrigerant heat exchanger. The second branch of the refrigerant line leads through the fourth heat exchanger 13, which is designed as an air-refrigerant heat exchanger and is provided and arranged for heat exchange between the refrigerant and the ambient air.

[0041] It is also conceivable to arrange the fourth heat exchanger 13 for heat exchange with exhaust air. The exhaust air would, for example, be room air from a building that is discharged outside.

[0042] After the fourth heat exchanger 13, the second branch flows into the first branch of the refrigerant line after another shut-off valve 15. Before the further shut-off valve 15, a branch from the second branch leads to a first expansion element 17, which is designed as a shut-off expansion valve, and then continues through the fourth heat exchanger 13 to the suction gas inlet of the compressor 5. The fourth heat exchanger 13 can be operated both as a gas cooler / condenser and as an evaporator, with the line for operation as a gas cooler / condenser and the line for operation as an evaporator running separately.

[0043] After the first and second branches merge, the refrigerant line continues to the second heat exchanger 19, which can be operated as a gas cooler / condenser and is designed as a liquid-refrigerant heat exchanger. Thus, in heat pump mode, the second heat exchanger 19 is arranged downstream of the first heat exchanger 11 in the refrigerant flow direction, so that the warm refrigerant flows through it at a lower temperature than the first heat exchanger 11. In the refrigerant circuit 3, the first heat exchanger 11 and the second heat exchanger 19 are arranged in series, particularly in heat pump mode.

[0044] In refrigerant circuit 3, the refrigerant line splits after the second heat exchanger 19 into the third branch with the second expansion element 21 and the fourth branch with the third expansion element 23. The second and third expansion elements 21, 23 are both shut-off expansion valves. In the third branch, the cooled refrigerant, expanded in the second expansion element 21, flows further through the chiller 25 for heat absorption, where it evaporates, and finally to the suction gas inlet of the compressor 5.

[0045] In the fourth branch, the cooled refrigerant expanded in the third expansion element 23 flows further for heat absorption through the fourth heat exchanger 13, which is operated as an evaporator, and finally to the suction gas inlet of the compressor 5. The fourth heat exchanger 13 is therefore an evaporator in the refrigerant circuit 3 in parallel connection to the chiller 25. The refrigerant circuit 3 can be switched in such a way that the refrigerant can flow through the fourth heat exchanger 13 as an evaporator instead of the chiller 25 for heat absorption.

[0046] The motor of the compressor 5 is adjustable in its power so that the high pressure of the refrigerant on the high pressure side of the refrigerant circuit 3 can be changed.

[0047] The first heat exchanger 11 is also connected to the first fluid circuit 27, in which the first heat transfer fluid can be circulated, pumped by the first water pump 29. In this case, the first heat transfer fluid is water, although another suitable type of heat transfer fluid, such as a water-glycol mixture, is also conceivable. During heat pump operation, heat is transferred from the refrigerant to the first heat transfer fluid in the first heat exchanger 11. The first fluid circuit 27 functions as a heating circuit for the heater 31. The shut-off valve 33 can be used to prevent the flow of the first heat transfer fluid through the first heat exchanger 11, so that the first heat transfer fluid of the first fluid circuit 27 no longer transports heat to the heater 31.

[0048] Furthermore, the first heat exchanger 11 is also connected to another liquid line 35, through which service water from the service water tank 39, pumped by the second water pump 37, can flow to absorb heat from the refrigerant in the first heat exchanger 11. Thus, in addition to its location on the high-pressure side of the refrigerant circuit 3, the first heat exchanger 11 is connected to two liquid lines, so that heat from the refrigerant can be used, on the one hand, to heat service water and, on the other hand, to heat the first heat transfer fluid. For example, the first heat exchanger 11 comprises three concentrically arranged tubes of different diameters, with the medium-diameter tube for the refrigerant, the small-diameter tube for service water, and the largest-diameter tube for the first heat transfer fluid.

[0049] The second heat exchanger 19, also arranged as a gas cooler / condenser in the refrigerant circuit 3, is connected to the liquid line 43, which can be shut off with the shut-off valve 41, as the inlet for domestic water to the domestic water tank 39, so that the refrigerant, which is no longer as warm there during heat pump operation as in the first heat exchanger 11, can continue to transfer heat at a lower temperature to the colder domestic water in the inlet. Furthermore, according to the invention, this second heat exchanger 19 is connected to the second liquid circuit 45, through which heat can be transported from the refrigerant to the heat accumulator 49 by means of a heat transfer fluid pumped by the third water pump 47.In addition to being integrated into the refrigerant circuit 3, the second heat exchanger 19 is connected, on the one hand, to the inlet for domestic water and, on the other hand, to the second liquid circuit 45 for the heat transfer from the refrigerant to the heat accumulator 49, so that heat can be transferred from the refrigerant to the domestic water or to the heat accumulator 49 using shut-off valves 41 and 51, respectively. The second heat transfer fluid in this case is water, although another suitable type of heat transfer fluid, such as a water-glycol mixture, is also conceivable. The heat accumulator 49, on the other hand, is not directly connected to the first liquid circuit 27, so that heat cannot be directly transported from or to the heat accumulator 49 using the first heat transfer fluid of the first liquid circuit 27, which makes the heat accumulator 49 less position-independent from the first liquid circuit 27.

[0050] An alternative design is also conceivable in which, instead of the second heat exchanger 19, another heat exchanger of the refrigerant circuit 3 is connected to the liquid line 43 of the domestic water inlet. This additional heat exchanger would be arranged parallel or in series with the second heat exchanger 19 on the high-pressure side of the refrigerant circuit 3.

[0051] The chiller 25 is also connected to a liquid line 53 through which, when the shut-off valve 55 is open, the second heat transfer liquid can transport heat from the heat accumulator 49 to the refrigerant in the chiller 25. The refrigerant there absorbs this heat as it evaporates. The liquid line 53 is part of the second liquid circuit 45. Depending on the switching of the two shut-off valves 51 and 55, when the third water pump 47 is running, the second heat transfer liquid flows either through the chiller 25 for heat transport from the heat accumulator 49 or through the second heat exchanger 19 for heat transport to the heat accumulator 49. When such heat transfer of the refrigerant in the second heat exchanger 19 is switched on, the refrigerant circuit 3 can be switched in heat pump mode such that the refrigerant can flow through the fourth heat exchanger 13 as an evaporator instead of the chiller 25.

[0052] In addition, the chiller 25 is connected to the first liquid circuit 27 for the switchable heat absorption of the refrigerant from the first heat transfer fluid, so that for such a cooling operation with the first water pump 29, with the shut-off valve 33 closed and the further shut-off valve 61 open, the first heat transfer fluid can be pumped not through the first heat exchanger 11 but through the chiller 25, and thus the heater 31 can operate in cooling mode, i.e., as a room-cooling air conditioning system. An alternative embodiment is also conceivable in which, instead of the chiller 25, another chiller of the refrigerant circuit 3 is connected to the first liquid circuit 27. This additional chiller would be arranged parallel or in series with the chiller 25 on the low-pressure side of the refrigerant circuit 3.

[0053] The heat storage unit 49 comprises, for example, a ground loop as a ground collector. Furthermore, it is conceivable that the heat storage unit 49 can also be charged with heat from an external heat source, such as geothermal energy or a district heating source. For example, a brine circuit for heat from geothermal energy as a heat source can be designed to be connected to the heat storage unit 49 and / or to the chiller 25 via the liquid line 53.

[0054] A solar collector 57 is thermally connected to the heat storage tank 49 via a fluid circuit with a controllable pump 59 for heat transfer. The control unit 63 controls the pump 59 and thus the thermal connection between the solar collector 57 and the heat storage tank 49. The control unit 63 also controls the compressor 5 as well as the shut-off valves, expansion devices, and pumps of the heat pump system 1. This allows various operating modes of the heat pump system 1 to be set.

[0055] The control system 63 receives data on the heat level of the heat storage tank 49, the time, the date, and the location coordinates determined, for example, by GPS, as well as data from temperature sensors, in particular regarding the temperatures of the ambient air, the heat storage medium of the heat storage tank 49 from the temperature sensor 50 there, and the domestic hot water tank 39 from the temperature sensor 40 there, as well as data from the Internet regarding the weather forecast, especially the temperature forecast for the following days and nights, via wired or wireless data connections for setting the appropriate and efficient operating mode. The control system 63, equipped with a processor, determines the charge level of the heat storage tank 49 and, from the received data, calculates, among other things, a discharge forecast for the heat storage tank 49. This forecast, along with the charge level, influences the efficiency requirement when selecting and determining the duration of the operating mode of the heat pump system 1.Thus, the controller 63 can set the charging of the heat storage tank 49 with heat from the refrigerant flowing through the second heat exchanger 19 during heat pump operation for space heating and / or domestic water heating through heat release from the refrigerant in the first heat exchanger 11 as an efficient operating mode, with a view to later, quieter nighttime heating by the heat pump system 1 with heat from the charged heat storage tank 49. Information received from the internet regarding the solar yield from the solar collector 57 is also taken into account in the discharge forecast for the heat storage tank 49.

[0056] For reasons of clarity, the wired or wireless data connections and control connections of the control system 63 with the Internet and the other sensors, in particular those for ambient air temperatures and room air temperatures, as well as the components of the heat pump system 1 to be controlled, are not shown in the figures.

[0057] In the Figures 2 to 8 are schematically shown various operating modes of the method for operating the device that can be set by the control 63. Figure 1 illustrated embodiment of a heat pump system 1. The reference numerals correspond to those in Figure 1 Lines carrying refrigerant are marked with bold solid lines, while lines carrying no refrigerant are marked with thin dotted lines. Lines carrying service water or heat transfer fluid are marked with bold dashed lines.

[0058] In Figure 2A schematic representation of a type of pure heat pump operation of the heat pump system 1 is shown. In the refrigerant circuit 3, on the high-pressure side downstream of the compressor 5, with the shut-off valve 7 open, the refrigerant flows through the first heat exchanger 11 and the second heat exchanger 19 in series, one after the other. As an expansion element, only the second expansion element 21 is open for expanding and cooling the refrigerant, so that the refrigerant on the low-pressure side of the refrigerant circuit 3 only flows through the chiller 25 on its way to the suction gas inlet of the compressor 5 for evaporation. The shut-off valves 9 and 15 as well as the first and third expansion elements 17, 23 are closed in the refrigerant circuit 3. Furthermore, the second water pump 37 for the domestic water is switched off, and the shut-off valves 41, 51, and 61 are closed.With the shutoff valve 33 open, only the first heat transfer fluid of the first fluid circuit 27 is pumped through the first heat exchanger 11, apart from the hot refrigerant. It absorbs heat from the refrigerant and transports it to the heater 31 for space heating. When the second heat exchanger 19 is inoperative, only the refrigerant flows through it. The fourth heat exchanger 13 is also inoperative.

[0059] The refrigerant, expanded only in the second expansion element 21, evaporates in the chiller 25, absorbing heat not from the first heat transfer fluid, but only from the heat accumulator 49, which is supplied by the second heat transfer fluid through the fluid line 53 from the heat accumulator 49. The solar collector 57 charges the heat accumulator 49 with heat. No heat is transferred from the refrigerant to the heat accumulator 49.

[0060] In Figure 3is shown schematically, a heat pump operation of the heat pump system 1 with charging operation for charging the heat accumulator 49. This operating mode is switched during heat pump operation depending on the demand for heat supply to the heat accumulator 49. With the shut-off valve 7 open, the refrigerant compressed in the compressor 5 flows first through the first heat exchanger 11 and then through the second heat exchanger 19, where it has a lower temperature due to the heat transfer in the first heat exchanger 11 to the first heat transfer fluid. This lower temperature of the refrigerant is still sufficient, however, for the refrigerant to transfer heat to the second heat transfer fluid in the second fluid circuit 45, which, with the shut-off valve 51 open and the further shut-off valve 55 closed, transports the heat to the heat accumulator 49 pumped by the third water pump 47. The heat accumulator 49 is thereby charged with heat.At the same time, for space heating, the heater 31 is supplied with heat via the first liquid circuit 27, which was transferred from the refrigerant in the first heat exchanger 11 to the first heat transfer liquid.

[0061] The refrigerant, which is expanded only in the third expansion element 23, evaporates in the fourth heat exchanger 13, absorbing heat from the ambient air.

[0062] Chiller 25, on the other hand, is not flowing through by the refrigerant and is therefore out of function.

[0063] The shut-off valves 9 and 15 as well as the first and second expansion valves 17, 21 are closed in the refrigerant circuit 3. Furthermore, the second water pump 37 for the domestic water is switched off and the shut-off valves 41, 55, and 61 are closed.

[0064] For example, with a set high pressure of the refrigerant of 125 bar and a drive power of the motor of the compressor 5 of 13.65 kW, the heat output delivered by the refrigerant in the first heat exchanger 11 for the heater 31 at a temperature of up to 60 °C can be 25.77 kW and the heat output delivered by the refrigerant in the second heat exchanger 19 to the heat accumulator 49 at a temperature of up to 10 °C can be 25.67 kW.

[0065] At only 100 bar high pressure with a drive power of 11.17 kW, the heat output delivered to heater 31 at a temperature of up to 60 °C can be 15.25 kW, and the heat output delivered to heat storage 49 at a temperature of up to 10 °C can be 33.42 kW. At only 80 bar high pressure with a drive power of 7.34 kW, for example, the heat output delivered to heater 31 at a temperature of up to 60 °C can be 7.34 kW, and the heat output delivered to heat storage 49 at a temperature of up to 10 °C can be 38.67 kW.

[0066] The solar collector 57 can be thermally connected to the heat storage unit 49 for additional loading of the heat storage unit 49 with heat.

[0067] In Figure 4Another type of pure heat pump operation of the heat pump system 1 with domestic water heating is shown schematically. This heat pump operation is switched depending on the demand for domestic water heating. The refrigerant draws heat only from the ambient air in the fourth heat exchanger 13. The heat accumulator 49 is neither charged with heat from the refrigerant of the refrigerant circuit 3, nor does it release heat for the refrigerant. No refrigerant flows through the chiller 25. With the shut-off valve 7 open, the hot refrigerant compressed in the compressor 5 first flows through the first heat exchanger 11, where it releases heat both for space heating of the heater 31 to the first heat transfer fluid of the first fluid circuit 27 and heat to the domestic water pumped through the first heat exchanger 11 by the second water pump 37.Furthermore, the refrigerant in the second heat exchanger 19 continues to transfer heat to the cold domestic water flowing through the liquid line 43 of the supply line opened by the shut-off valve 41. As an expansion element, only the third expansion element 23 is open to expand and cool the refrigerant, so that it evaporates only in the fourth heat exchanger 13 upon absorption of heat from the ambient air. The shut-off valves 9 and 15 as well as the first and second expansion elements 17, 21 are closed in the refrigerant circuit 3. Furthermore, the water pump 47 for the second heat transfer fluid is switched off, and the shut-off valves 51, 55, and 61 are closed.

[0068] The solar collector 57 is thermally connected to the heat storage unit 49 in order to charge it with heat.

[0069] The heating of the domestic water in the first heat exchanger 11 is largely independent of the set operating mode of the heat pump system 1. Whenever heated refrigerant flows through the first heat exchanger 11, there is also the possibility of the refrigerant releasing heat for domestic water if domestic water heating is required. Thus, by appropriately controlling the second water pump 37, the heating of the domestic water in the first heat exchanger 11 can be switched on and off. Pure heat pump operation can even be adjusted with the control system 63 so that only domestic water in the first and second heat exchangers 11, 19 is heated, and heat transfer to the first and second heat transfer fluids is switched off.

[0070] In the second heat exchanger 19, provided that heat transfer to the second heat transfer fluid of the second fluid circuit 45 is disabled, heat transfer to the cold domestic water can be set largely independently of the currently set operating mode of the heat pump system 1. For example, a cooling mode with heat transfer from the first heat transfer fluid to the refrigerant in the chiller 25 can be set such that domestic water is heated by the refrigerant in the first and second heat exchangers 11, 19.

[0071] In Figure 5 is shown schematically a heat pump operation of the heat pump system 1 with defrost function at the fourth heat exchanger 13. The circuit of the compressor 5, the shut-off valves, expansion devices and pumps of the heat pump system 1 set by the control 63 corresponds to the Figure 2described, except that the shut-off valves 9 and 15 in the refrigerant circuit 3 are also open, so that, connected in parallel to the first heat exchanger 11, a portion of the hot refrigerant compressed by the compressor 5 also flows through the fourth heat exchanger 13, thereby defrosting it. Upstream of the second heat exchanger 19 in the refrigerant flow direction, the two partial refrigerant flows then reunite.

[0072] In Figure 6A pure cooling operation of the heat pump system 1 is shown schematically. The cooling operation is switched depending on the cooling requirement. The compressed hot refrigerant coming from the compressor 5 flows, with the shut-off valves 9 and 15 open, through the fourth heat exchanger 13, which is used as a gas cooler / condenser, where the refrigerant releases heat to the ambient air. Depending on the need to heat domestic water in the first heat exchanger 11, which can be switched on in parallel with the fourth heat exchanger 13, the shut-off valve 7 is opened, so that the compressed hot refrigerant then flows partially or alternatively to the fourth heat exchanger 13 through the first heat exchanger 11 to heat domestic water pumped by the second water pump 37. The shut-off valve 33 in the first liquid circuit 27 is closed, so that no first heat transfer fluid flows through the first heat exchanger 11.

[0073] The refrigerant then passes through the second heat exchanger 19 on the high-pressure side of the refrigerant circuit 3, which is either out of function or in which, when the shut-off valve 41 is open, the refrigerant continues to release heat to cold domestic water.

[0074] The refrigerant, which is only expanded in the second expansion element 21, evaporates in the chiller 25, where it absorbs heat not from the heat accumulator 49, but from the first heat transfer fluid, which, when the shut-off valve 61 is open, circulates with the first water pump 29 in the first fluid circuit 27 in such a way that the heater 31 is supplied with the first heat transfer fluid cooled in the chiller 25, so that the heater 31 functions as a cooling system, i.e. as a room-cooling air conditioning system.

[0075] The solar collector 57 charges the heat storage tank 49 with heat. However, no heat is transferred from the refrigerant to the heat storage tank 49. In the second fluid circuit 45, the third water pump 47 is switched off and the shut-off valves 51 and 55 are closed. Furthermore, the first and third expansion elements 17, 23 are closed.

[0076] In Figure 7 A cooling operation of the heat pump system 1 with charging operation for charging the heat storage 49 is shown schematically. The circuit of the compressor 5, the shut-off valves, expansion devices and pumps of the heat pump system 1 set by the control 63 corresponds to the Figure 6except for the difference that the shut-off valve 41 for cold domestic water is closed and in the second liquid circuit 45 the third water pump 47 is switched on and the shut-off valve 51 is opened, so that in the second heat exchanger 19 heat from the refrigerant is not transferred to domestic water but to the second heat transfer fluid and is thus transported to the heat accumulator 49 in which the heat is stored.

[0077] In Figure 8 A pure charging operation for charging the heat storage unit 49 is shown schematically.

[0078] The hot refrigerant compressed by the compressor 5 flows in the refrigerant circuit 3 with the shutoff valve 7 open through the first heat exchanger 11, in which no heat is transferred from the refrigerant to the domestic water or the first heat transfer fluid, to the second heat exchanger 19, where the refrigerant transfers heat to the second heat transfer fluid. The second heat transfer fluid, pumped by the third water pump 47, transports the heat to the heat accumulator 49 in the second fluid circuit 45, where the heat is stored.

[0079] The refrigerant, which is expanded only in the third expansion element 23, evaporates in the fourth heat exchanger 13, absorbing heat from the ambient air.

[0080] Chiller 25, on the other hand, is not flowing through by the refrigerant and is therefore out of function.

[0081] The shut-off valves 9 and 15 as well as the first and second expansion devices 17, 21 are closed in the refrigerant circuit 3. Furthermore, the first and second water pumps 29, 37 are switched off and the shut-off valves 33, 41, 55, and 61 are closed.

[0082] The solar collector 57 can be thermally connected to the heat storage unit 49 for additional loading of the heat storage unit 49 with heat.

[0083] In Figure 9 A further embodiment of a heat pump system 1 according to the invention is shown schematically. This corresponds to the Figure 1illustrated heat pump system 1, except that the first heat exchanger 11 is not connected to the liquid line 35 for domestic water, but rather, in the refrigerant circuit 3, upstream of the first heat exchanger 11 in the refrigerant flow direction, a fifth heat exchanger 65 designed as a liquid-refrigerant heat exchanger and operable as a gas cooler / condenser is arranged for heat transfer from the refrigerant to the domestic water and is connected to the liquid line 35 for domestic water. When the second water pump 37 is switched on, domestic water is pumped from the domestic water tank 39 through the fifth heat exchanger 65 and heated there by the compressed hot refrigerant also flowing through it.The coolant subsequently flowing through the first heat exchanger 11 then has a lower temperature than in the fifth heat exchanger 65, which, however, is still sufficient in heat pump operation for heating the first heat transfer fluid in the first fluid circuit 27 for the heater 31 for space heating. Otherwise, refer to the description of the heat pump system 1. Figure 1 where all reference numerals of the Figure 1 shown embodiment of a heat pump system 1 in which Figure 9 illustrated embodiment of a heat pump system 1 are the same.

[0084] In the Figure 10 In the schematically shown further embodiment of a heat pump system 1, the refrigerant circuit 3 corresponds to that in the embodiment in Figure 9shown, in which the fifth heat exchanger 65 is also arranged for heat transfer from the refrigerant to the domestic water and is connected to the liquid line 35 for domestic water. The first liquid circuit 27 is still connected to the first heat exchanger 11 for heat absorption of the first heat transfer liquid from the refrigerant, but no longer to the chiller 25, so that the first liquid circuit 27 can only be used as a heating circuit for heat transfer to the heater 31 for space heating and no longer as a cooling circuit, whereby the two still in Figure 9 The shut-off valves 33 and 61 shown have been eliminated as they are no longer required.

[0085] For cooling operation of the heat pump system 1, a third fluid circuit 67 containing a third heat transfer fluid that can be pumped therein by the fourth water pump 69 is connected to the chiller 25 for heat absorption of the refrigerant from the third heat transfer fluid. The third heat transfer fluid thus serves to transport heat from the heater 31 to the refrigerant flowing through the chiller 25, so that the third fluid circuit 67 is a cooling circuit for the heater 31, which is used for space cooling in cooling mode.

[0086] Furthermore, the second liquid circuit 45 with its heat transfer liquid is still connected to the second heat exchanger 19 for heat transfer from the coolant to the heat accumulator 49, but no longer to the chiller 25, so that the second liquid circuit 45 can no longer be used for heat transfer from the heat accumulator 49 to the coolant in the chiller 25, whereby the two still in Figure 9 The shut-off valves 51 and 55 shown have been eliminated as they are no longer required. The chiller 25 is connected to the liquid line 53, which is separate from the second liquid circuit 45, to absorb heat from the refrigerant from the second heat transfer fluid. The fifth water pump 71 can pump the second heat transfer fluid through the liquid line 53 from the heat accumulator 49 to the chiller 25, thereby transporting heat from the heat accumulator 49 to the refrigerant.

[0087] Except for these deviations described, the Figure 10 The heat pump system 1 shown with the same reference numerals corresponds to that shown in Figure 9 shown heat pump system.

[0088] In Figure 11 A further embodiment of a heat pump system 1 according to the invention is shown schematically. This corresponds to the Figure 10illustrated heat pump system 1, with the difference that in the refrigerant circuit 3, the branch on the high-pressure side to the fourth heat exchanger 13 is not arranged upstream of the fifth heat exchanger 65, but downstream of the first heat exchanger 11, and accordingly the shut-off valves 7 and 9 in the two branches are arranged after the branch. Through the second heat exchanger 19, refrigerant is then reunited in one refrigerant line, and refrigerant from both branches can flow. In the high-pressure region of the refrigerant circuit 3, the fourth heat exchanger 13 can be connected in series downstream of the fifth and first heat exchangers 65, 11 in the refrigerant flow direction.

[0089] In the respective procedure for operating the Figure 9 , 10 and 11 In the embodiments shown, the respective heat pump system 1 is in the same operating modes as the one in Figure 1shown heat pump system 1. In this regard, reference is made to the description of the Figures 2 to 8 reference is made to the operating modes shown.

[0090] The Figure 1 , 9 , 10 and 11 The embodiments of the heat pump system 1 shown can be provided and designed either for space heating, space cooling and domestic water heating of a building or for a vehicle, such as a rail vehicle or bus.

[0091] Conceivable are the Figure 9 , 10 and 11 shown embodiments, alternative embodiments in which, instead of the second heat exchanger 19, a further heat exchanger of the refrigerant circuit 3 is connected to the liquid line 43 of the domestic water inlet and, instead of the chiller 25, a further chiller is connected to the liquid circuit provided for cooling for the cooling operation of the heater 31.

[0092] In Figure 12 An exemplary embodiment of a method for operating a heat pump system is shown as a flow chart. The heat pump system is, for example, one of the Figure 1 , 9 to 11 heat pump systems shown.

[0093] In the first step 100, the controller receives data on the charge level of the heat storage tank, such as, in particular, the temperature of the heat storage medium and / or the amount of latent heat stored in the heat storage medium. Furthermore, the controller receives data on the temperature of the ambient air, room air, and the domestic water in the domestic water tank from the corresponding temperature sensors. Furthermore, in step 100, the controller receives data regarding a weather forecast via the internet or via a wireless connection, such as, in particular, the forecast of the ambient air temperature and the expected solar yield. The expected solar yield relates, in particular, to that of the solar collector of the heat pump system.

[0094] In the next step 110, the processor-equipped control system creates a discharge forecast for the heat storage using the received data, taking into account possible operating modes of the heat pump system. These operating modes are the Figures 2 to 8 described. When creating the discharge forecast for the heat storage, the expected solar yield from the solar collector of the heat pump system is also taken into account. For example, when heating room air and domestic hot water in heat pump operation, the discharge forecast takes into account how long and with what heat output the Figure 3The operating mode shown here, where the heat storage is simultaneously charged with heat from the refrigerant flowing through the second heat exchanger, could be achieved without the efficiency of the heat pump system for space heating and domestic hot water heating becoming too low. For example, if a very cold night is expected, the heat storage could be charged with heat during the evening hours and then used for heating in the Figure 2 The operating mode shown above should be used. Such a scenario would be taken into account in the discharge forecast.

[0095] In the following step 120, the control system selects an operating mode of the heat pump system, taking into account the discharge forecast for the heat storage created in step 110. For example, for the next two hours, the Figure 3The operating mode of the heat pump operation with loading of the heat storage tank is selected and then, for example, for the following four hours the Figure 2 shown operating mode of pure heat pump operation.

[0096] Finally, in step 130, the operating mode selected in step 120 is set by appropriate control of the compressor, the shut-off valves, the expansion devices and the pumps of the heat pump system under the control of the controller.

[0097] After a specified period of time, for example ten minutes, the process begins again.

Claims

1. A heat pump system (1) with a refrigerant circuit (3) comprising a compressor (5), at least one first heat exchanger (11) and a second heat exchanger (19), each designed as a liquid-refrigerant heat exchanger and operable as a gas cooler / condenser, at least one expansion element (17, 21, 23), at least one chiller (25) designed as a liquid-refrigerant heat exchanger, and at least one fourth heat exchanger (13) operable as an evaporator in parallel with the chiller (25), wherein, in heat pump operation, the first heat exchanger (11) is arranged upstream of the second heat exchanger (19) in the refrigerant flow direction and is also connected to the first liquid circuit (27), which is preferably a heating circuit, for heat transfer from a refrigerant of the refrigerant circuit (3) to a first heat-transfer liquid of a first liquid circuit (27),and the chiller (25) for absorbing heat from the refrigerant from a second heat transfer fluid is also connected to a fluid line (53) for heat transfer from a heat source and / or a heat accumulator (49), characterized in that the second heat exchanger (19) is connected to a second liquid circuit (45) for switchable heat release from the refrigerant to the heat accumulator (49), and the refrigerant circuit (3) is designed to be switchable such that, in heat pump operation, when such heat release in the second heat exchanger (19) is switched on, the refrigerant can flow through the fourth heat exchanger (13) as an evaporator instead of the chiller (25).

2. Heat pump system (1) according to claim 1 characterized in thatthe second liquid circuit (45) comprises at least one shut-off valve (51, 55) switchably connecting the liquid line (53) for the second heat transfer liquid to the chiller (25), and the second liquid circuit (45) is switchable such that the second heat transfer liquid can flow either through the chiller (25) or through the second heat exchanger (19).

3. Heat pump system (1) according to claim 1 or 2 characterized in that the first heat exchanger (11) is also connected to a further liquid line (35) for heat transfer from the refrigerant to the service water, or in the refrigerant circuit (3) upstream of the first heat exchanger (11) in the refrigerant flow direction, a fifth heat exchanger (65) designed as a liquid-refrigerant heat exchanger and operable as a gas cooler / condenser is arranged for heat transfer from the refrigerant to the service water and is connected to the further liquid line (35).

4. Heat pump system (1) according to one of claims 1 to 3 characterized in that for heat transfer from the refrigerant to domestic water, a further liquid line (43) is connected to the second heat exchanger (19) or to a possibly further heat exchanger of the refrigerant circuit (3).

5. Heat pump system (1) according to one of claims 1 to 4 characterized in thatit is designed in such a way that it can also be operated in cooling mode, wherein the chiller (25) or an optionally further chiller for absorbing heat from the refrigerant of the refrigerant circuit (3) is connected either from the first heat transfer fluid to the first liquid circuit (27), or from an optionally third heat transfer fluid to an optionally third liquid circuit (67), which is preferably a cooling circuit, and the heat pump system (1) is switchable for cooling mode in such a way that the heat transfer in the first heat exchanger (11) from the refrigerant to the first heat transfer fluid and the heat transfer in the chiller (25) from the second heat transfer fluid to the refrigerant are switched off.

6. Heat pump system (1) according to claim 5 characterized in thatthe fourth heat exchanger (13) is designed as an air-refrigerant heat exchanger such that it can be operated as an evaporator in heat pump mode and as a gas cooler / condenser in cooling mode and is provided for heat exchange of the refrigerant with ambient air or exhaust air.

7. Heat pump system (1) according to one of claims 1 to 6 characterized in that it comprises at least one solar collector (57) which can be thermally connected to the heat accumulator (49) for heat transfer via a liquid circuit.

8. Heat pump system (1) according to one of claims 1 to 7 characterized in that the heat accumulator (49) comprises at least one ground loop with heat transport fluid for geothermal energy, and / or a network with heat transport fluid, such as a district heating network or a part thereof.

9. Heat pump system (1) according to one of claims 1 to 8 characterized in thatit comprises a control system (63) designed in such a way for controlling the heat pump system (1), with which shut-off valves (7, 9, 15) and expansion elements (17, 21, 23) of the refrigerant circuit (3) and pumps (29, 47) and / or shut-off valves (33, 51, 55, 61) of the first and second liquid circuits (27, 45) can be controlled at least in such a way that the two operating modes - of operating the heat pump system (1) in pure heat pump operation with heat release from the refrigerant for domestic water and / or for space heating and heat absorption of the refrigerant from the second heat transfer fluid in the chiller (25), or - of operating the heat pump system (1) in such heat pump operation with heat release from the refrigerant for domestic water and / or for space heating,in which the heat absorption of the refrigerant in the fourth heat exchanger (13) and at the same time the heat release in the second heat exchanger (19) from the refrigerant through the second liquid circuit (45) to the heat accumulator (49) are adjustable., 10. Heat pump system (1) according to claim 9 characterized in thatthe control (63) is designed in such a way - that the heat transfer in the second heat exchanger (19) or in the optionally further heat exchanger from the refrigerant to the domestic water can be switched on and off and the heat transfer in the first heat exchanger (11) or optionally fifth heat exchanger (65) from the refrigerant to the domestic water can be switched on and off, and / or - that the heat pump system (1) can be operated in cooling mode with the heat transfer from the refrigerant to the first heat transfer fluid in the first heat exchanger (11) switched off and the heat absorption of the refrigerant from the first or optionally third heat transfer fluid in the chiller (25) or optionally in the additional chiller switched on,and / or - that the further two operating modes of operation in pure charging mode with only heat release in the second heat exchanger (19) from the refrigerant through the second liquid circuit (45) to the heat accumulator (49) and simultaneous heat absorption of the refrigerant in the fourth heat exchanger (13), or in charging mode with cooling mode with heat release in the second heat exchanger (19) from the refrigerant through the second liquid circuit (45) to the heat accumulator (49) and simultaneous heat absorption of the refrigerant in the chiller (25) or in the optionally further chiller from the first or optionally third heat transfer fluid, can be set under the control of the controller (63), and / or - that the controller (63) receives data from temperature sensors (40, 50) for temperatures of domestic water, ambient air, room air and the heat storage medium of the heat accumulator (49), as well as data relating to a weather forecast, for selecting the operating mode of the heat pump system (1).

11. Heat pump system (1) according to one of claims 1 to 10 characterized in that it is intended and designed at least for space heating of a building.

12. Heat pump system (1) according to one of claims 1 to 7 and 9 to 10 characterized in that it is intended and designed for a vehicle.

13. Method for operating a heat pump system (1) according to one of claims 1 to 12 characterized in thatthe refrigerant circuit (3) and the first and second liquid circuits (27, 45) can be controlled in such a way that, at least partly depending on the state of charge of the heat accumulator (49), the heat pump system (1) is operated in one of the at least three controllable operating modes - pure heat pump operation with heat release from the refrigerant for domestic water and / or for space heating and with heat absorption of the refrigerant from the second heat transfer liquid in the chiller (25), or - heat pump operation with heat release from the refrigerant for domestic water and / or for space heating with heat absorption of the refrigerant in the fourth heat exchanger (13) and, at the same time, heat release in the second heat exchanger (19) from the refrigerant through the second liquid circuit (45) to the heat accumulator (49), or - pure heat pump operation with heat release from the refrigerant for domestic water and / or for space heating and with heat absorption of the refrigerant in the fourth heat exchanger (13).

14. Method according to claim 13 characterized in that as required, heat for domestic water is released from the refrigerant in the first heat exchanger (11) or, if applicable, fifth heat exchanger (65), and, if heat is not released from the refrigerant to the heat accumulator (49) in the second heat exchanger (19), as required, heat for domestic water is released from the refrigerant in the second heat exchanger (19) or, if applicable, in the further heat exchanger of the refrigerant circuit (3).

15. Method according to claim 13 or 14 characterized in that the heat pump system (1) according to claim 10 is operated in cooling mode with the heat transfer from the refrigerant to the first heat transfer fluid in the first heat exchanger (11) switched off and the heat absorption of the refrigerant from the first or optionally third heat transfer fluid in the chiller (25) or in the optionally further chiller switched on, depending on the cooling requirement.

16. Method according to one of claims 13 to 15 characterized in that the refrigerant circuit (3) and the first and second liquid circuits (27, 45) and optionally the third liquid circuit (67) can be controlled in such a way that the heat pump system (1) is operated in the selectable further operating modes of charging operation with cooling operation or pure charging operation with only heat release in the second heat exchanger (19) from the refrigerant through the second liquid circuit (45) to the heat accumulator (49) and at the same time heat absorption of the refrigerant in the fourth heat exchanger (13) or in cooling operation in the chiller (25) or in the optionally further chiller by the first or optionally third heat transfer liquid.

17. Method according to one of claims 13 to 16 characterized bythe steps a) of receiving (100) data from temperature sensors (40, 50) for temperatures of domestic water, ambient air, room air, and the heat storage medium of the heat storage device (49), as well as receiving (100) data on the charge state of the heat storage device (49), such as in particular the amount of latent heat stored in the heat storage medium, and regarding a weather forecast, b) evaluating the received data for selecting an operating mode according to one of claims 13 to 16, taking efficiency requirements into account, wherein a discharge forecast for the heat storage device (49) is calculated using the received data, taking into account possible operating modes of the heat pump system (1) according to one of claims 13 to 16, and, if the heat pump system (1) comprises the features of claim 7, also taking into account the solar yield from the solar collector (57) anticipated from the received data regarding the weather forecast,is created, c) selecting an operating mode of the heat pump system (1) based on the result of the evaluation in step b) taking into account the discharge forecast created for the heat accumulator (49), and d) setting (130) the operating mode of the heat pump system (1) selected in step c).

Images