Heat pump system and method for operating same

Abstract

The invention relates to a heat pump system W for an electrically driven vehicle, comprising a coolant side and a refrigerant side. The coolant side has a coolant circuit with a coolant pump (2) for generating and circulating a coolant flow, a first heat exchanger (4) for dissipating heat from the coolant circuit to the refrigerant, a second heat exchanger (6) for dissipating heat from the air in the interior of a cabin of the vehicle, an energy storage device (8) for supplying a drive (10) of the vehicle with electrical energy, and a valve system V (12, 14) for distributing the coolant, said heat pump system W being designed such that in a first operating state, a coolant flow KS of the coolant pump (2) can be divided by the valve system V (12) such that one coolant sub-flow KTS1 is guided through the first heat exchanger (4) and one coolant sub-flow KTS2 bypasses the first heat exchanger (4) by means of a bypass line (16) of the coolant circuit.

Description

[0001] Heat pump system and method for its operation

[0002] Description

[0003] The present invention relates to a heat pump system for an electrically powered vehicle of the type mentioned in the preamble of claim 1 and a method for its operation.

[0004] Such heat pump systems for electrically powered vehicles and methods for their operation are state of the art in numerous

[0005] Design variants are already known. The known heat pump systems for electric vehicles comprise a coolant side for circulating a coolant and a refrigerant side, which is fluidically separated from the coolant side, for circulating a refrigerant, wherein the coolant side and the refrigerant side are in a heat transfer connection, and wherein the coolant side has a coolant circuit with a coolant pump for generating and circulating a coolant flow, a first heat exchanger for discharging heat from the coolant circuit to the refrigerant of the refrigerant side, a second heat exchanger for discharging heat from an interior air of a

[0006] Vehicle cabin of the vehicle to the coolant circuit, an energy storage device for supplying a drive of the vehicle with electrical energy and a valve system for distributing the coolant.

[0007] A major challenge is the simultaneous cooling of the interior and the battery, i.e., the energy storage device. State-of-the-art electric vehicles use the refrigerant system to cool the interior and battery regardless of the outside temperature. The interior is cooled by an air-to-refrigerant heat exchanger, the evaporator, with the required cooling capacity and evaporation temperature controlled by a first expansion valve. Battery cooling is achieved by a coolant-to-refrigerant heat exchanger, the so-called chiller, whose cooling capacity and evaporation temperature are controlled by a second expansion valve. A characteristic of the refrigerant system is the equivalence of evaporation pressure and evaporation temperature.Since the evaporator and chiller have very different target temperatures (typically, the target temperature for the evaporator is 3 to 5 °C and for the chiller greater than 20 °C), the evaporation pressures also differ accordingly. However, the refrigerant flows from the evaporator and chiller are returned together to the refrigerant compressor of the refrigerant system, so that the different pressure levels are equalized. Due to the equivalence of evaporation pressure and evaporation temperature, the evaporation temperature in the evaporator rises, so that the target temperature of 3 to 5 °C is exceeded. Therefore, there is a conflict of objectives between, on the one hand, efficient cooling of the interior and, on the other hand, efficient cooling of the battery.

[0008] This is where the present invention comes in.

[0009] The present invention is based on the object of improving a heat pump system for an electrically powered vehicle and a method for its operation.

[0010] This object is achieved by a heat pump system W for an electrically operated vehicle with the features of claim 1, which is characterized in that the heat pump system W is designed such that in a first operating state of the heat pump system W a coolant flow KS of the coolant pump can be divided by means of the valve system V in such a way that on the one hand a coolant partial flow KTS1 is flow-guided through the first heat exchanger and on the other hand a coolant partial flow KTS2 is flow-guided past the first heat exchanger by means of a bypass line of the coolant circuit, wherein the two aforementioned coolant partial flows KTS1, KTS2 reunite downstream of the first heat exchanger and the reunited coolant flow KS is returned to the coolant pump, preferably without flowing through further components of the coolant circuit, such as the energy storage device.Furthermore, this object is achieved by a method for operating a heat pump system W having the features of claim 8. The subclaims relate to advantageous developments of the invention.

[0011] A significant advantage of the invention lies in particular in the fact that a heat pump system for an electrically powered vehicle and a method for operating it are improved. Due to the inventive design of the heat pump system W and the method for operating it, it is possible to significantly improve the efficiency of the heat pump system W and thus of a thermal management system of an electrically powered vehicle equipped therewith in a circuit-technically simple manner. This is because the heat pump system W according to the invention enables a very flexible heat-transfer coupling between heat sources of the heat pump system W and heat sinks of the heat pump system W to be realized. Accordingly, even inherently complex thermal management tasks for electrically powered vehicles can be solved much more simply and thus more cost-effectively.The invention enables dual thermal management, which uses coolant, for example, cooled by a chiller with an expansion valve, for cooling both the interior and the battery. This avoids the conflict of objectives described above, caused by the parallel operation of two expansion valves. For this purpose, the heat pump system W according to the invention has a valve system V, which enables the demand-based distribution and temperature control of the coolant for the interior and battery, i.e., the vehicle cabin and the energy storage unit.

[0012] In principle, the heat pump system W according to the invention can be freely selected within wide, suitable limits in terms of type, mode of operation, components, material, and dimensions. For example, the heat pump system W according to the invention can be advantageously used for an electrically powered vehicle, both for purely electric vehicles and for so-called hybrid vehicles, i.e. vehicles that have, on the one hand, an internal combustion engine and, on the other hand, an electric motor for driving the vehicle. In particular, this is intended for land vehicles, such as road vehicles or the like. However, the invention can also be used for other types of vehicles. Furthermore, it is possible for the second heat exchanger to be arranged, for example, in a separate coolant circuit, wherein the first heat exchanger can also be part of this coolant circuit.The term “coolant circuit” is to be understood generally here and thus also includes in particular embodiments and operating states of the heat pump system according to the invention in which the coolant of the respective coolant circuit flows through certain components of this coolant circuit as required or not. The respective coolant circuit should therefore not be thought of as static. The respective coolant circuit is therefore not identical to the coolant system as a whole, but merely a part of the coolant system of the heat pump system W according to the invention, wherein this part can be flowed through by coolant in a fluidically separate manner from the rest of the coolant system. Furthermore, embodiments of the invention are conceivable in which the aforementioned coolant circuit only has the aforementioned components in direct, i.e. immediate, flow-conducting connection to one another.Accordingly, the method according to the invention can also be freely selected within wide suitable limits.

[0013] A particularly advantageous development of the heat pump system W according to the invention provides that the heat pump system W is designed such that in the first operating state of the heat pump system W the coolant flow KS of the coolant pump can be divided by means of the valve system V in such a way that on the one hand the coolant partial flow KTS1 flows through the first heat exchanger and subsequently through the second heat exchanger and on the other hand the coolant partial flow KTS2 is fluidly guided past the first heat exchanger and the second heat exchanger by means of the bypass line of the coolant circuit, wherein the two aforementioned coolant partial flows KTS1, KTS2 reunite downstream of the first heat exchanger and the second heat exchanger and the reunited coolant flow KS is returned to the coolant pump, preferably without flowing through further components of the coolant circuit, such as the energy storage device.As a result, the heat pump system W according to the invention is designed in a particularly suitable manner. For example, the required coolant quantity can be easily adjusted depending on the cooling capacity of the first heat exchanger, for example, a chiller, to cool the interior air.

[0014] Accordingly, an advantageous development of the method according to the invention provides that in the first operating state of the heat pump system W, the coolant flow KS of the coolant pump is divided by means of the valve system V in such a way that, on the one hand, the coolant partial flow KTS1 flows through the first heat exchanger and subsequently through the second heat exchanger and, on the other hand, the coolant partial flow KTS2 is fluidly guided past the first heat exchanger and the second heat exchanger by means of the bypass line of the coolant circuit, wherein the two aforementioned coolant partial flows KTS1, KTS2 reunite downstream of the first heat exchanger and the second heat exchanger and the reunited coolant flow KS is returned to the coolant pump, preferably without flowing through further components of the coolant circuit, such as the energy storage device.

[0015] A further advantageous development of the heat pump system W according to the invention provides that the heat pump system W is designed such that, in a second operating state of the heat pump system W, the coolant flow KS is initially guided according to the first operating state and, after the two aforementioned coolant partial flows KTS1, KTS2 have been combined by means of the valve system V, the coolant flow KS first flows through the energy storage device or a third heat exchanger of the coolant circuit to cool the energy storage device and is then returned to the coolant pump. In this way, the required quantity of coolant can be adjusted very precisely; this quantity is required for cooling the interior air and the battery depending on the cooling capacity of the first heat exchanger, for example a chiller.The optional third heat exchanger can, for example, be connected to the energy storage device in a heat-transfer manner by means of a cooling liquid other than the aforementioned coolant.

[0016] Accordingly, an advantageous development of the method according to the invention provides that in a second operating state of the heat pump system W, the coolant flow KS is initially guided according to the first operating state and the coolant flow KS, after the two aforementioned partial coolant flows KTS1, KTS2 have been combined by means of the valve system V, first flows through the energy storage device or a third heat exchanger of the coolant circuit to cool the energy storage device and is then returned to the coolant pump.

[0017] Another advantageous development of the heat pump system W according to the invention provides that the heat pump system W is designed such that in a third operating state of the heat pump system W the coolant flow KS is initially guided according to the first operating state and the coolant flow KS can be divided by means of the valve system V after the two aforementioned coolant partial flows KTS1, KTS2 have been combined in such a way that upstream of the coolant pump a coolant partial flow KTS3 flows directly to the coolant pump and a coolant partial flow KTS4 first flows through the energy storage device or a third heat exchanger of the coolant circuit to cool the energy storage device and is then returned to the coolant pump.This allows, for example, the inlet temperature to the coolant pump to be reduced at high energy storage temperatures, such as temperatures above 35°C, since the heated coolant from the battery, i.e., the energy storage unit, is cooled by the coolant flowing directly back to the coolant pump. Thus, the coolant in the first heat exchanger, e.g., a chiller, needs to be cooled less (since the incoming coolant is less hot), improving the efficiency of the overall system, i.e., the heat pump system W according to the invention. See also the above comments on the optional third heat exchanger.Accordingly, an advantageous development of the method according to the invention provides that in a third operating state of the heat pump system W, the coolant flow KS is initially guided according to the first operating state and the coolant flow KS is divided by means of the valve system V after the two aforementioned coolant partial flows KTS1, KTS2 have been combined in such a way that upstream of the coolant pump, a coolant partial flow KTS3 flows directly to the coolant pump and a coolant partial flow KTS4 first flows through the energy storage device or a third heat exchanger of the coolant circuit to cool the energy storage device and is then returned to the coolant pump.

[0018] The designation of the aforementioned operating states of the heat pump system W according to the invention as first, second, and third operating states merely serves to distinguish these operating states and does not imply that there necessarily exists a second and third operating state. Therefore, it is not a list of operating states, according to which the presence of a third operating state would necessarily require the presence of a second operating state. The same applies to the other operating states according to the exemplary embodiment explained below.

[0019] A further advantageous development of the heat pump system W according to the invention provides that the heat pump system W is designed such that the respective division of the coolant flow KS is continuously enabled by means of the valve system V, preferably such that a complete fluidic bypass of the first heat exchanger and / or the second heat exchanger is enabled by means of the valve system V. In this way, in the heat pump system W according to the invention, mixed positions between the operating states are also enabled by means of its valve system V, so that, for example, in an intermediate position between the first and the second operating state, the first heat exchanger, for example a chiller, can be fully flowed through at any time, whereas a flow rate through the second heat exchanger, an air-coolant heat exchanger, is adaptable and thus adjustable.Accordingly, an advantageous development of the method according to the invention provides that the respective division of the coolant flow KS is carried out continuously by means of the valve system V, preferably that a complete fluidic bypass of the first heat exchanger and / or the second heat exchanger is carried out by means of the valve system V, if required.

[0020] As already explained above, the heat pump system W according to the invention can be freely configured within wide, suitable limits. An advantageous development of the heat pump system W according to the invention expediently provides that the valve system V is arranged, on the one hand, downstream of the first heat exchanger or downstream of the first heat exchanger and the second heat exchanger, and, on the other hand, upstream of the coolant pump. Advantageously, the valve system V of the heat pump system W according to the invention has a plurality of valves, wherein the valve system V preferably has only a first valve and a second valve.

[0021] The invention is explained in more detail below using the attached, roughly schematic drawing. It shows:

[0022] Fig. 1 shows an embodiment of the heat pump system according to the invention for carrying out the method according to the invention in a process diagram, in a first operating state,

[0023] Fig. 2 shows the embodiment in a representation analogous to Fig. 1, in a second operating state,

[0024] Fig. 3 shows the embodiment in a representation analogous to Fig. 1, in a third operating state,

[0025] Fig. 4 shows the embodiment in a representation analogous to Fig. 1, in a fourth operating state, Fig. 5 shows the embodiment in a representation analogous to Fig. 1, in a fifth operating state and

[0026] Fig. 6 shows the embodiment in a representation analogous to Fig. 1, in a sixth operating state.

[0027] In Figures 1 to 6, an embodiment of the heat pump system according to the invention for carrying out the method according to the invention is shown purely by way of example.

[0028] The heat pump system W for an electrically powered vehicle (not shown in detail) comprises a coolant side for circulating a coolant (not shown) and a refrigerant side, fluidically separated from the coolant side, for circulating a refrigerant (not shown). The coolant side and the refrigerant side are in heat transfer communication. The coolant side is shown in Figs. 1 to 6 with solid and dashed lines, with these lines being thick when coolant is flowing through it and thin when it is not flowing through it. The refrigerant side is shown in Figs. 1 to 6 with dotted lines.The coolant side has a coolant circuit, shown in solid lines, with a coolant pump 2 for generating and circulating a coolant flow, a first heat exchanger 4 designed as a chiller for transferring heat from the coolant circuit to the coolant on the coolant side, a second heat exchanger 6 for transferring heat from the interior air of a vehicle cabin (not shown) of the vehicle to the coolant circuit, an energy storage device 8, i.e., a battery, for supplying a drive 10 of the vehicle with electrical energy, and a valve system V for distributing the coolant. The valve system V of the coolant circuit here has a first valve 12 and a second valve 14.

[0029] According to the invention, the heat pump system W is designed such that, in a first operating state of the heat pump system W shown in Fig. 1, a coolant flow KS of the coolant pump 2 can be divided by means of the valve system V, namely by means of the first valve 12, such that, on the one hand, a coolant partial flow KTS1 is flow-guided through the first heat exchanger 4 and, on the other hand, a coolant partial flow KTS2 is flow-guided past the first heat exchanger 4 by means of a bypass line 16 of the coolant circuit, wherein the two aforementioned coolant partial flows KTS1, KTS2 reunite downstream of the first heat exchanger 4 and the reunited coolant flow KS is returned to the coolant pump. There is no flow through the energy storage device 8.

[0030] In the present exemplary embodiment, the heat pump system W is even designed such that, in the first operating state of the heat pump system W, the coolant flow KS of the coolant pump 2 can be divided by means of the valve system V, namely the first valve 12, such that, on the one hand, the coolant partial flow KTS1 flows through the first heat exchanger 4 and subsequently through the second heat exchanger 6, and, on the other hand, the coolant partial flow KTS2 is fluidly guided past the first heat exchanger 4 and the second heat exchanger 6 by means of the bypass line 16 of the coolant circuit, wherein the two aforementioned coolant partial flows KTS1, KTS2 reunite downstream of the first heat exchanger 4 and the second heat exchanger 6, and the reunited coolant flow KS is returned to the coolant pump 2. As already explained above, there is no flow through the energy storage device 8 in this case.

[0031] Furthermore, the heat pump system W is designed as follows: namely, that in a second operating state of the heat pump system W, the coolant flow KS is initially guided according to the first operating state and the coolant flow KS, after the two aforementioned coolant partial flows KTS1, KTS2 have been combined by means of the valve system V, namely the second valve 14, first flows through the energy storage device 8 and is then returned to the coolant pump 2;namely, that in a third operating state of the heat pump system W, the coolant flow KS is initially guided according to the first operating state and, after the two aforementioned coolant partial flows KTS1, KTS2 have been combined, the coolant flow KS can be divided by means of the valve system V in such a way that, upstream of the coolant pump 2, a coolant partial flow KTS3 flows directly to the coolant pump 2 and a coolant partial flow KTS4 first flows through the energy storage device 8 and is then returned to the coolant pump 2.;

[0032] As an alternative to the present exemplary embodiment, embodiments of the invention would also be conceivable that include a third heat exchanger in the coolant circuit for cooling the energy storage device. This third heat exchanger can be connected to the energy storage device in a heat-transfer manner, for example, using a different cooling fluid than the aforementioned coolant. Accordingly, in these embodiments of the invention, the coolant flow KS / the partial coolant flow KTS4 would not flow directly through the energy storage device in the second and / or third operating state, but rather through the third heat exchanger.

[0033] The heat pump system W is also designed such that the respective division of the coolant flow KS is continuously enabled by means of the valve system V, wherein a complete fluidic bypass of the first heat exchanger 4 and / or the second heat exchanger 6 is enabled by means of the valve system V. For this purpose, the coolant circuit here has a bypass line 18 in addition to the bypass line 16. As can also be seen from Figs. 1 to 6, the valve system V with the first and second valves 12, 14 is arranged on the one hand downstream of the first heat exchanger 4 and the second heat exchanger 6 and on the other hand upstream of the coolant pump 2. The valve system V for the coolant circuit here comprises only the first valve 12 and the second valve 14.Although the coolant circuit also has flow-conducting connections to a remainder of the coolant system, the heat pump system W is designed such that the coolant circuit, as can be seen in a synopsis of Figs. 1 to 6, can be flowed through with coolant separately from this remainder of the coolant system. The mode of operation of the heat pump system according to the invention and the method according to the invention according to the present embodiment are explained in more detail below with reference to Figs. 1 to 6.

[0034] In the first operating state shown in Fig. 1, the coolant flow KS of the coolant pump 2 is divided by means of the valve system V in such a way that, on the one hand, the coolant partial flow KTS1 flows through the first heat exchanger 4 and subsequently through the second heat exchanger 6 and, on the other hand, the coolant partial flow KTS2 is flow-guided past the first heat exchanger 4 and the second heat exchanger 6 by means of the bypass line 16 of the coolant circuit, the two aforementioned coolant partial flows KTS1, KTS2 reuniting downstream of the first heat exchanger 4 and the second heat exchanger 6 and the reunited coolant flow KS being returned to the coolant pump 2. Only the interior, i.e. the interior air of the vehicle cabin, is cooled by means of the cooling circuit.Accordingly, in the first operating state, the coolant pump 2 generates a coolant flow that partially flows through the chiller 4 and the air-coolant heat exchanger 6 as coolant partial flow KTS1, and partially bypasses these two aforementioned components via the bypass line 16 as coolant partial flow KTS2. This allows the required coolant quantity to be set very precisely, which is required to cool the interior air depending on the cooling capacity of the chiller 4. In particular, the aforementioned division of the coolant flow KS allows the coolant to be cooled directly to the target temperature of 3 to 5 °C. Thus, at a very high coolant temperature, for example, greater than 35 °C, immediately after the vehicle is started in summer, it is possible to correspondingly reduce the coolant quantity flowing through the chiller 4 so that the coolant can be cooled directly to the required target temperature.This allows the time required to provide cold coolant, i.e., cold air, for the interior to be significantly reduced (the time required depends essentially on the performance of the refrigerant system). In the second operating state of the heat pump system W shown in Fig. 2, the coolant flow KS is initially guided according to the first operating state, wherein, after the two aforementioned partial coolant flows KTS1, KTS2 have been combined by means of the valve system V, the coolant flow KS first flows through the energy storage unit 8 and is then returned to the coolant pump 2. The interior and the battery, i.e., the energy storage unit 8, are thus cooled by means of the cooling circuit.Accordingly, in this second operating state, the coolant pump 2 generates a coolant flow that partially flows through the chiller 4 and the air-to-coolant heat exchanger 6 as the coolant partial flow KTS1, and partially bypasses these two aforementioned components via the bypass line 16 as the coolant partial flow KTS2. This allows the required coolant quantity to be adjusted very precisely, which, depending on the cooling capacity of the chiller 4, is needed to cool the interior air and the battery 8. The coolant is first cooled in the chiller 4 and then reheated in the air-to-coolant heat exchanger 6 by the incoming interior air.The amount of coolant flowing as the partial coolant flow KTS1 is adjusted so that the interior air is cooled to the desired target temperature of 3 to 5 °C, while the coolant is warmed to such an extent, namely above 10 °C, that the temperature of the total coolant flow KS, which is composed of the partial coolant flows KTS1 and KTS2, corresponds to the desired target temperature for battery cooling of greater than 20 °C. The total coolant flow KS is then passed through the battery 8 and warmed by it, after which the coolant flows back to the coolant pump 2.

[0035] The third operating state shown in Fig. 3 is similar to the second operating state. However, by means of the valve system V, the coolant partial flow KTS3 of the total coolant flow KS, which is composed of the recombined coolant partial flows KTS1 and KTS2, flows directly back to the coolant pump 2, while the coolant partial flow KTS4 flows to the battery 8 and then to the coolant pump 2. As a result, at high battery temperatures of, for example, 35°C, the inlet temperature to the coolant pump 2 can be reduced, since the heated coolant from the battery 8 is cooled by the cool coolant flowing directly back to the coolant pump 2. As a result, the coolant in the chiller 4 needs to be cooled less (since the inflowing coolant is less hot), thus improving the efficiency of the overall system, i.e., the heat pump system W.

[0036] The heat pump system W of the present embodiment additionally has the operating states shown in Figs. 4 to 6. In the fourth operating state according to Fig. 4, the bypass line 18 is used, so that the chiller 4 is flowed through, bypassing the air-coolant heat exchanger 6. This operating state thus serves solely to cool the battery 8. In the fifth operating state according to Fig. 5, the bypass line 16 is used, so that both the chiller 4 and the air-coolant heat exchanger 6 are bypassed. In this operating state, the battery 8 is not cooled, but rather coolant flows through the battery 8 only to equalize the temperature of the individual battery cells of the battery 8. The battery cells are not shown. The sixth operating state according to Fig. 6 is analogous to the third operating state.However, the coolant flow KS through the chiller 4 and the air-coolant heat exchanger 6 is adjusted such that the coolant is cooled according to the cooling requirement for the interior and is then heated such that the battery 8 is essentially not flowed through for cooling, but again only for equalizing the temperature of the individual battery cells in the battery 8.

[0037] The invention is not limited to the present embodiment. See, for example, the relevant statements in the introduction to the description as well as the alternative or optional features in the illustrated embodiment. List of reference symbols

[0038] 2 coolant pump

[0039] 4 First heat exchanger, designed as a chiller

[0040] 6 Second heat exchanger, designed as an air-coolant heat exchanger

[0041] 8 Energy storage, also known as battery

[0042] 10 Vehicle drive

[0043] 12 First valve of the valve system V

[0044] 14 Second valve of the valve system V

[0045] 16 Bypass line

[0046] 18 Bypass line

[0047] KS coolant flow, also called total coolant flow

[0048] KTS coolant partial flow, namely KTS1, KTS2, KTS3 and KTS4

[0049] V valve system

[0050] W Heat pump system W

Claims

Heat pump system and method for its operation Patent claims 1. Heat pump system W for an electrically powered vehicle, comprising a coolant side for circulating a coolant and a refrigerant side, fluidically separated from the coolant side, for circulating a refrigerant, wherein the coolant side and the refrigerant side are in a heat transfer connection, and wherein the coolant side has a coolant circuit with a coolant pump (2) for generating and circulating a coolant flow, a first heat exchanger (4) for transferring heat from the coolant circuit to the refrigerant of the refrigerant side, a second heat exchanger (6) for transferring heat from an interior air of a vehicle cabin of the vehicle to the coolant circuit, an energy storage device (8) for supplying a drive (10) of the vehicle with electrical energy, and a valve system V (12, 14) for distributing the coolant, characterized in that the heat pump system W is designed such thatthat in a first operating state of the heat pump system W, a coolant flow KS of the coolant pump (2) can be divided by means of the valve system V (12) in such a way that, on the one hand, a coolant partial flow KTS1 is flow-guided through the first heat exchanger (4) and, on the other hand, a coolant partial flow KTS2 is flow-guided past the first heat exchanger (4) by means of a bypass line (16) of the coolant circuit, wherein the two aforementioned coolant partial flows KTS1, KTS2 reunite downstream of the first heat exchanger (4) and the reunited coolant flow KS is returned to the coolant pump (2).

2. Heat pump system W according to claim 1, characterized in that that the heat pump system W is designed such that in the first operating state of the heat pump system W the coolant flow KS of the coolant pump (2) can be divided by means of the valve system V (12) in such a way that on the one hand the coolant partial flow KTS1 flows through the first heat exchanger (4) and subsequently through the second heat exchanger (6) and on the other hand the coolant partial flow KTS2 is fluidly guided past the first heat exchanger (4) and the second heat exchanger (6) by means of the bypass line (16) of the coolant circuit, wherein the two aforementioned coolant partial flows KTS1, KTS2 reunite downstream of the first heat exchanger (4) and the second heat exchanger (6) and the reunited coolant flow KS is returned to the coolant pump (2).

3. Heat pump system W according to claim 1 or 2, characterized in that the heat pump system W is designed such that in a second operating state of the heat pump system W the coolant flow KS is initially guided according to the first operating state and the coolant flow KS, after the two aforementioned coolant partial flows KTS1, KTS2 have been combined by means of the valve system V (14), first flows through the energy store (8) or a third heat exchanger of the coolant circuit to cool the energy store and is then returned to the coolant pump (2).

4. Heat pump system W according to one of claims 1 to 3, characterized in that the heat pump system W is designed such that in a third operating state of the heat pump system W, the coolant flow KS is initially guided according to the first operating state and the coolant flow KS after the combination of the two aforementioned coolant partial flows KTS1, KTS2 by means of the valve system V (14) such can be divided so that upstream of the coolant pump (2) a coolant partial flow KTS3 flows directly to the coolant pump (2) and a coolant partial flow KTS4 first flows through the energy storage device (8) or a third heat exchanger of the coolant circuit to cool the energy storage device and is then returned to the coolant pump (2).

5. Heat pump system W according to one of claims 1 to 4, characterized in that the heat pump system W is designed such that the respective division of the coolant flow KS is made possible continuously by means of the valve system V (12, 14), preferably that a complete fluidic bypass of the first heat exchanger (4) and / or the second heat exchanger (6) is made possible by means of the valve system V (12, 14).

6. Heat pump system W according to one of claims 1 to 5, characterized in that the valve system V (12, 14) is arranged on the one hand downstream of the first heat exchanger or downstream of the first heat exchanger (4) and the second heat exchanger (6) and on the other hand upstream of the coolant pump (2).

7. Heat pump system W according to one of claims 1 to 6, characterized in that the valve system V (12, 14) has a plurality of valves (12, 14), preferably that the valve system V (12, 14) has only a first valve (12) and a second valve (14).

8. Method for operating a heat pump system W according to one of claims 1 to 7, characterized in that in a first operating state of the heat pump system W, a coolant flow KS of the coolant pump (2) is divided by means of the valve system V (12) in such a way that, on the one hand, a coolant partial flow KTS1 is flow-guided through the first heat exchanger (4) and, on the other hand, a coolant partial flow KTS2 is flow-guided past the first heat exchanger (4) by means of a bypass line (16) of the coolant circuit, the two aforementioned coolant partial flows KTS1, KTS2 reuniting downstream of the first heat exchanger (4) and the reunited coolant flow KS being returned to the coolant pump (2).

9. The method according to claim 8, characterized in that in the first operating state of the heat pump system W, the coolant flow KS of the coolant pump (2) is divided by means of the valve system V (12) in such a way that, on the one hand, the coolant partial flow KTS1 flows through the first heat exchanger (4) and subsequently through the second heat exchanger (6) and, on the other hand, the coolant partial flow KTS2 is fluidly guided past the first heat exchanger (4) and the second heat exchanger (6) by means of the bypass line (16) of the coolant circuit, the two aforementioned coolant partial flows KTS1, KTS2 reuniting downstream of the first heat exchanger (4) and the second heat exchanger (6) and the reunited coolant flow KS is returned to the coolant pump (2).

10. Method according to claim 8 or 9, characterized in that in a second operating state of the heat pump system W, the coolant flow KS is initially guided according to the first operating state and the coolant flow KS, after the two aforementioned coolant partial flows KTS1, KTS2 have been combined by means of the valve system V (14), first flows through the energy storage device (8) or a third heat exchanger of the coolant circuit to cool the energy storage device and is then returned to the coolant pump (2). 11 . Method according to one of claims 8 to 10, characterized in that in a third operating state of the heat pump system W the coolant flow KS is initially guided according to the first operating state and the coolant flow KS is divided after the two aforementioned coolant partial flows KTS1, KTS2 have been combined by means of the valve system V (14) in such a way that upstream of the coolant pump (2) a coolant partial flow KTS3 flows directly to the coolant pump (2) and a coolant partial flow KTS4 first flows through the energy storage device (8) or a third heat exchanger of the coolant circuit to cool the energy storage device and is then returned to the coolant pump (2).

12. Method according to one of claims 8 to 11, characterized in that the respective division of the coolant flow KS is carried out continuously by means of the valve system V (12, 14), preferably that by means of the valve system V (12, 14) a complete fluidic bypass of the first heat exchanger (4) and / or the second heat exchanger (6) is carried out if necessary.

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