Thermal management system for vehicles and methods for operating such a thermal management system

Abstract

A thermal management system with a compressor heat pump assembly (HP) and control unit (30) for vehicles is described, in which the risk of liquid refrigerant entering the compressor (2) is reduced. A corresponding method for operating the thermal management system is also described. For this purpose, a refrigerant storage medium (16) with a switchable valve assembly (18) is provided between the condenser outlet (4-0) of the cabin condenser (4) and a position between the valve outlet (EXV-0) of the expansion valve assembly (EXV) and the compressor inlet (2-i). By providing the refrigerant storage medium (16) with the switchable valve assembly (18), a portion of the refrigerant in the heat pump assembly (HP) can be temporarily stored outside the refrigerant receiver (14), thus lowering the liquid level in the refrigerant receiver (14) and reducing the risk of liquid refrigerant entering the compressor (2).

Description

[0001] The invention relates to a thermal management system for vehicles, in particular electric vehicles, according to claim 1 and a method for operating this thermal management system according to claim 12.

[0002] For the cooling and heating of vehicles, in particular electric vehicles, the applicant manufactures and markets thermal management systems with compressor heat pumps, as described in Fig. 9. The Fig. The thermal management system schematically illustrated in Figure 9 comprises a heat pump assembly HP and a controller 30 configured to operate the heat pump assembly (HP) in various operating modes. The heat pump assembly HP comprises a compressor 2 with a compressor inlet 2-i and a compressor outlet 2-o, a cabin condenser 4 with a condenser inlet 4-i and a condenser outlet 4-o, an outdoor heat exchanger 6 with an outdoor heat exchanger inlet 6-i, an outdoor heat exchanger outlet 6-o, and a first expansion valve EXV1, an evaporator device 8 with an evaporator inlet 8-i and an evaporator outlet 8-o, and a refrigerant collector 14 with a refrigerant collector inlet 14-i and a refrigerant collector outlet 14-o.

[0003] The compressor outlet 2-o is connected to the cabin condenser inlet 4-i, and the compressor inlet 2-i is connected to the refrigerant collector outlet 14-o. The first expansion valve EXV1 is arranged between the cabin condenser outlet 4-o and the outdoor heat exchanger inlet 6-i. The evaporator device 8 comprises an expansion valve device EXV with a valve inlet EXV-i and a valve outlet EXV-o. The valve outlet EXV-o of the expansion valve device EXV is connected to the evaporator inlet 8-i of the evaporator device 8. The outdoor heat exchanger outlet 6-o is connected to the refrigerant collector inlet 14-i via a first shutoff valve SOV1. The condenser outlet 4-o of the cabin condenser 4 is connected via a line (10) with a second shut-off valve SOV2 to the valve inlet EXV-i of the expansion valve device EXV.The outdoor heat exchanger outlet 6-o is also connected to the valve inlet EXV-i of the expansion valve assembly EXV via a check valve 12. The refrigerant collector inlet 14-i is also connected to the evaporator outlet 8-o of the evaporator assembly 8, and the refrigerant collector outlet 14-o is connected to the compressor inlet 2-i.

[0004] The various operating modes include heating and cooling mode. The heating mode includes a special variant, a heat boost mode. In heat boost mode, a portion of the hot and compressed refrigerant is diverted from the compressor outlet 2-o and fed via a bypass line 20 to a bypass expansion valve EXV. BPis returned to the refrigerant collector inlet 14-i in order to heat the evaporator device 8 or the external heat exchanger 6 without introducing heat. Refrigerant is pumped in a circuit via the bypass line 20 in order to load the compressor 2 and use its waste heat to heat the vehicle cabin.

[0005] A disadvantage of this known arrangement is that at low suction pressure at the compressor inlet 2-i, typically when starting the vehicle or the thermal management system, the amount of refrigerant in the refrigerant collector 14 is very high. Therefore, there is a risk that liquid refrigerant will enter the compressor inlet 2-i and the compressor 2, which could lead to damage to the compressor 2.

[0006] Based on the state of the art according to Fig. 10, the object of the present invention is to provide a thermal management system with a compressor heat pump arrangement and control system for vehicles, in which the risk of liquid refrigerant being supplied to the compressor is reduced. Furthermore, the object of the invention is to provide a corresponding method for operating the thermal management system.

[0007] These objects are achieved by a thermal management system according to claim 1 and a method for operating the thermal management system according to claim 12.

[0008] A refrigerant storage medium with a switchable valve device is provided between the condenser outlet of the cabin condenser and a position between the valve outlet of the expansion valve device and the compressor inlet. By providing the refrigerant storage medium with a switchable valve device, a portion of the refrigerant in the heat pump arrangement can be temporarily stored outside the refrigerant receiver, thus lowering the liquid level in the refrigerant receiver and reducing the risk of liquid refrigerant being fed into the compressor.

[0009] The advantageous arrangement of the refrigerant storage means according to claim 2 has proven advantageous. This also allows existing components of the heat pump arrangement to be used as refrigerant storage.

[0010] The advantageous embodiment according to claim 3 enables the heat boost mode. In heat boost mode, the vehicle cabin is heated exclusively or largely via the compressor waste heat. Due to components filled with liquid refrigerant, more refrigerant is required in heat boost mode than in heat pump mode. Consequently, when the thermal management system starts up, there is more refrigerant in the refrigerant receiver, and the risk of liquid refrigerant entering the compressor is greater. Therefore, the refrigerant storage medium is particularly useful in heat boost mode.

[0011] Preferably, the evaporator device comprises a cabin evaporator for cooling the vehicle cabin and a chiller for utilizing the waste heat from the battery and other vehicle components - claim 4.

[0012] Preferably, either the unused outdoor heat exchanger (claim 5) or the unused cabin evaporator (claim 6) is used as the refrigerant storage medium. In these cases, no additional component needs to be used as the refrigerant storage medium. Only the switchable valve device needs to be added if necessary.

[0013] Alternatively, according to claim 7, the refrigerant storage means can be designed as an additional component. This allows the refrigerant storage means to be specifically dimensioned for the intermediate storage of refrigerant.

[0014] Due to the advantageous embodiment according to claim 8, the refrigerant storage medium is arranged in a higher-temperature area, e.g., in the engine compartment or in the area of ​​lines with hot fluid. The higher temperature facilitates the return of the refrigerant to the heat pump circuit, and the return of the refrigerant can also occur at a higher suction pressure, since the higher temperature in the area of ​​the refrigerant storage medium also results in a higher saturation pressure.

[0015] The embodiments according to claims 9 and 10 relate to advantageous embodiments for the switchable valve device.

[0016] The internal heat exchanger according to claim 11 increases the efficiency of the thermal management system.

[0017] According to claim 12, the thermal management system or heat pump arrangement is operated to heat the vehicle cabin. If the compressor's suction pressure is below the saturation pressure of the refrigerant at ambient temperature in the range of the refrigerant storage medium, refrigerant is temporarily stored in the refrigerant storage medium - method step b). This removes refrigerant from the heat pump circuit and lowers the level of liquid refrigerant in the refrigerant receiver, reducing the risk of liquid refrigerant entering the compressor. As the compressor's suction pressure increases over time, the refrigerant receiver begins to empty, and more and more refrigerant is circulating.The refrigerant must be removed from the refrigerant storage medium and returned to the heat pump circuit before the suction pressure exceeds the saturation pressure at ambient temperature in the area of ​​the refrigerant storage medium - i.e. in the refrigerant storage medium.

[0018] The return of the refrigerant, process step c), should begin at the earliest when the suction pressure has exceeded its absolute minimum and is continuously increasing without a further drop - claim 13.

[0019] In heat booster mode, a large amount of refrigerant is required in the circuit. When the thermal management system starts up, this refrigerant may be in the refrigerant receiver. There is an increased risk of liquid entering the compressor. Therefore, temporary refrigerant storage is advisable when starting up in heat booster mode - claim 14.

[0020] According to the advantageous embodiments according to claims 15 and 16, the external heat exchanger is used as a refrigerant storage medium. According to claim 15, refrigerant is first supplied to the external heat exchanger - process step b) and withdrawn from the heat pump circuit and the refrigerant collector. Shortly before the compressor suction pressure rises above the saturation pressure of the refrigerant at ambient temperature in the area of ​​the refrigerant storage medium, the refrigerant is returned from the external heat exchanger to the heat pump circuit - process step c).

[0021] According to claim 16, in process step b), refrigerant is also temporarily stored in the external heat exchanger. When the external heat exchanger is "filled" after a short time, refrigerant is continuously withdrawn from the external heat exchanger and simultaneously continuously reinserted, so that a certain amount of refrigerant remains in the external heat exchanger - process step b). Shortly before the compressor suction pressure rises above the saturation pressure of the refrigerant at ambient temperature in the area of ​​the refrigerant storage medium, the supply of refrigerant to the external heat exchanger is discontinued, and the refrigerant in the external heat exchanger is discharged from the external heat exchanger - process step c).

[0022] Alternatively, according to claim 17, the cabin evaporator is used as a refrigerant storage device.

[0023] According to the advantageous embodiments according to claims 18 and 19, an additional component is used as a refrigerant storage medium. Analogous to claims 15 and 16, the intermediate storage of refrigerant in the additional component can be carried out in two steps—storage and retrieval—or continuous storage and retrieval with final retrieval. By using an additional component, it can be dimensioned according to the required storage requirements.

[0024] The temporary storage of refrigerant in the refrigerant storage medium also simplifies the use of CO2 or R744 as a refrigerant. Due to the Pressure Vessel Ordinance, the refrigerant receiver cannot simply be enlarged. However, in heat boost mode, more refrigerant is required for R744 than for other refrigerants due to the higher pressure dependence of the charge. By temporarily storing R744 in the refrigerant storage medium, the environmentally friendly R477 can be used without any problems as a refrigerant.

[0025] Further details, features, and advantages of the invention will become apparent from the following description of a preferred embodiment of the invention. It shows: Fig. 1 a pressure-time diagram when starting up the thermal management with the suction pressure at the compressor inlet in relation to the saturation pressure of the refrigerant used at ambient temperature; Fig. 2 the vapor fraction of the refrigerant at the compressor inlet over time; Fig. 3a shows the method step b) - storing refrigerant in the refrigerant storage means - according to a basic first embodiment of the invention; Fig. 3b shows the process step c) - the return of refrigerant from the refrigerant storage medium into the heat pump circuit - according to the first embodiment of the invention; Fig. 4a shows method step b) according to a second embodiment of the invention; Fig. 4b shows method step c) according to the second embodiment of the invention; Fig. 5a shows method step b) according to a third embodiment of the invention; Fig. 5b shows method step c) according to the third embodiment of the invention; Fig. 6a shows method step b) according to a fourth embodiment of the invention in which the cabin evaporator is used as a refrigerant storage means; Fig. 6b shows method step c) according to the fourth embodiment of the invention; Fig. 7a shows method step b) according to a fifth embodiment of the invention in which the refrigerant storage means is designed as an additional component; Fig. 7b shows method step c) according to the fifth embodiment of the invention; Fig. 8a shows method step b) according to a sixth embodiment of the invention in which the refrigerant storage means is designed as an additional component; Fig. 8b shows the method step c) according to the sixth embodiment of the invention; and Fig. 9 the structure of a thermal management system according to the state of the art.

[0026] Fig. Figure 1 schematically shows the vapor content of the refrigerant at the compressor inlet 2-i over time during start-up of the thermal management system. The lower the vapor content or the higher the liquid content in the refrigerant at the compressor inlet 8-i, the greater the risk of too much liquid refrigerant entering the compressor 2 and damaging it. This time period is shown in Fig. 2 is marked with a first double arrow DP1. Fig. Figure 2 shows a pressure-time diagram during start-up of the thermal management system, showing the suction pressure at compressor inlet 2-i and the saturation pressure of the refrigerant used at ambient temperature. A second double arrow, DP2, marks the time period with an increased risk of liquid refrigerant entering compressor 2 and thus the period during which countermeasures must be taken.

[0027] When starting the thermal management system or the heat pump arrangement HP, the suction pressure at the compressor inlet 2-i drops with a certain transient response; little refrigerant is required in circulation and the level of the liquid refrigerant in the refrigerant receiver 14 is high, and the liquid content in the refrigerant at the compressor inlet 2-i is high. As can be seen from Fig. 1, the risk of liquid refrigerant entering compressor 2 is increased. After a certain time, the suction pressure of compressor 2 begins to rise, and more refrigerant is required for circulation; the level in refrigerant receiver 14 drops, the vapor content in the refrigerant at the compressor inlet 2-i increases and increases, and there is no longer any risk of liquid refrigerant entering compressor 2.

[0028] To minimize the risk of liquid refrigerant entering the compressor in the time range indicated by the double arrow DP1 in Fig. 1, according to the present invention, a refrigerant storage means 16 is used in which refrigerant is temporarily stored, so that even in the time range of the double arrow DP1, the level in the refrigerant collector is lower, thereby reducing the risk of liquid refrigerant entering the compressor 2. An unused component of the heat pump assembly HP or an additional component can be used as the refrigerant storage means 16.

[0029] The Fig. 3a and Fig. 3b shows the schematic structure and function of a first basic embodiment of the invention. The thermal management system comprises a heat pump assembly HP and a controller 30 designed to operate the heat pump assembly HP in various operating modes. The heat pump assembly HP comprises a compressor 2 with a compressor inlet 2-i and a compressor outlet 2-o, a cabin condenser 4 with a condenser inlet 4-i and a condenser outlet 4-o, an outdoor heat exchanger 6 with an outdoor heat exchanger inlet 6-i, an outdoor heat exchanger outlet 6-o, and a first expansion valve EXV1, an evaporator device 8 with an evaporator inlet 8-i and an evaporator outlet 8-o, and a refrigerant collector 14 with a refrigerant collector inlet 14-i and a refrigerant collector outlet 14-o.

[0030] The compressor outlet 2-o is connected to the cabin condenser inlet 4-i, and the compressor inlet 2-i is connected to the refrigerant collector outlet 14-o. The first expansion valve EXV1 is arranged between the cabin condenser outlet 4-o and the outdoor heat exchanger inlet 6-i. The evaporator device 8 comprises an expansion valve device EXV with a valve inlet EXV-i and a valve outlet EXV-o. The valve outlet EXV-o of the expansion valve device EXV is connected to the evaporator inlet 8-i of the evaporator device 8. The outdoor heat exchanger outlet 6-o is connected to the refrigerant collector inlet 14-i via a first shutoff valve SOV1. The condenser outlet 4-o of the cabin condenser 4 is connected via a line (10) with a second shut-off valve SOV2 to the valve inlet EXV-i of the expansion valve device EXV.The outdoor heat exchanger outlet 6-o is also connected to the valve inlet EXV-i of the expansion valve assembly EXV via a check valve 12. The refrigerant collector inlet 14-i is also connected to the evaporator outlet 8-o of the evaporator assembly 8, and the refrigerant collector outlet 14-o is connected to the compressor inlet 2-i.

[0031] The thermal management system according to Fig. 3a and Fig. 3b therefore differs in its structure from the thermal management system according to Fig. 9 only by the lack of a bypass, which is not necessary for the basic function of the invention. The refrigerant storage means 16 in the first embodiment according to Fig. 3a and Fig. 3b the external heat exchanger 6 which is unused when starting up the thermal management system is used.

[0032] Fig. 3a shows the storage of liquid refrigerant in the external heat exchanger 6 used as refrigerant storage medium 16. For this purpose, the first expansion valve EXV1 between the cabin condenser 4 and the external heat exchanger 6 is opened with the first shut-off valve SOV1 closed, so that refrigerant is temporarily stored in the external heat exchanger 6 - process step b). Fig. 3b shows the return of the refrigerant temporarily stored in the refrigerant storage medium 16 into the heat pump circuit by opening the first shut-off valve SOV1 with the first expansion valve EXV1 closed - process step c).

[0033] In principle, intermediate storage can take place as long as the suction pressure of compressor 2 is below the saturation pressure of the refrigerant at ambient temperature in the range of the refrigerant storage medium. However, it must be taken into account that the refrigerant return - process step c) - must also take place as long as the suction pressure is below the saturation pressure of the refrigerant at ambient temperature in the range of the refrigerant storage medium. This results in the Fig. 2 as double arrow DP2 shown time window for the storage of refrigerant in the refrigerant storage medium 16. The time window indicated by the double arrow DP2 is thus shorter than the one indicated by the double arrow DP1 in Fig. 1 designated time window.

[0034] The recirculation can take place when the refrigerant level in the refrigerant receiver 14 drops significantly. This is the case when the suction pressure begins to rise continuously after passing the absolute minimum and the transient response; in Fig. 4 approximately from 280 sec. At an ambient temperature of 0°C in the area of ​​the refrigerant storage medium - Fig. 2 - the return can be started a little later; from about 370 seconds.

[0035] The thermal management system according to Fig. 4a and Fig. 4b according to a second embodiment does not differ in structure from the first embodiment. The difference lies solely in the design of method step b). In contrast to the first embodiment, in the second embodiment, in method step b), by adjusting the degree of opening of the first expansion valve EXV1 and the first shut-off valve SOV1, refrigerant is continuously temporarily stored in the external heat exchanger 6 used as the refrigerant storage medium 16 and is then discharged therefrom, so that a certain amount of refrigerant remains in the external heat exchanger 6. Method step c) is identical to method step c) according to the first embodiment of the invention; Fig. 3b and Fig. 4b are identical.

[0036] Fig. 5a and Fig. 5b shows a third embodiment of the invention in which the external heat exchanger 6 is also used as a refrigerant storage medium. The evaporator device 8 comprises a cabin evaporator 8-1 with a cabin evaporator inlet 8-1-i and a cabin evaporator outlet 8-1-o, and a chiller 8-2 with a chiller inlet 8-2-i and a chiller outlet 8-2-o. The expansion valve device EXV consists of a second and third expansion valve EXV2, EXV3, each with a valve inlet EXV2-i, EXV3-i and a valve outlet EXV2-o, EXV3-o. The valve outlet EXV2-o of the second expansion valve EXV2 is connected to the cabin evaporator inlet (8-1-i), and the valve outlet EXV3-o of the third expansion valve EXV3 is connected to the chiller inlet 8-2-i. Through a bypass line 20 with a fourth bypass expansion valve EXV BP, which is arranged between the compressor outlet (2-o) and the refrigerant receiver inlet (14-i), a heat boost mode is possible. Furthermore, an internal heat exchanger 22 with a heat-dissipating part 22-1 and a heat-absorbing part 22-2 is provided. The heat-dissipating part 22-1 is arranged with a first check valve CV1 between the external heat exchanger outlet 6-o and the valve inlets EXV2-i and EXV3-i of the second and third expansion valves EXV2 and EXV3. The heat-absorbing part 22-2 is arranged between the refrigerant receiver outlet 14-o and the compressor inlet 2-i.

[0037] The thermal management system can be operated in various modes, including heating and cooling. In heat pump mode, the vehicle cabin can be cooled by absorbing heat from the cabin evaporator 8-1. To heat the vehicle cabin, waste heat from the vehicle is coupled via the chiller 8-2, and the vehicle cabin is heated by heat dissipation from the cabin condenser. The heating mode includes a special variant, the heat boost mode, to heat the vehicle cabin without heat input to the chiller 8-2. In heat boost mode, most of the hot and compressed refrigerant is branched off from the compressor outlet 2-o and fed via the bypass line 20 to the bypass expansion valve EXV. BPreturned to the refrigerant collector inlet 14-i and the evaporation of the liquid refrigerant from the chiller 8-2 occurs through the hot refrigerant from the bypass line 20. The internal heat exchanger 22 further increases the efficiency of the thermal management.

[0038] Analogous to the first embodiment, this also occurs in the third embodiment according to Fig. 5a the storage of liquid refrigerant in the external heat exchanger 6 used as refrigerant storage medium 16. For this purpose, the first expansion valve EXV1 between the cabin condenser 4 and the external heat exchanger 6 is opened with the first shut-off valve SOV1 closed, so that refrigerant is temporarily stored in the external heat exchanger 6 - process step b). Fig. 5b shows analogous to Fig. 3b the return of the refrigerant temporarily stored in the refrigerant storage medium 16 / external heat exchanger 6 into the heat pump circuit by opening the first shut-off valve SOV1 with the first expansion valve EXV1 closed - process step c).

[0039] Analogous to the embodiment according to Fig. 4a can also be used for the construction of the heat pump arrangement HP according to Fig. 5a and Fig. 5b also realize the process step b) by continuously storing and discharging refrigerant in and out of the refrigerant storage medium 16 / external heat exchanger 6 - not shown.

[0040] The Fig. 6a and Fig. 6b shows a fourth embodiment of the invention, in which the cabin evaporator 8-1 is used as the refrigerant storage means 16. The structure of the heat pump assembly HP is identical to the structure of the third embodiment. Fig. Figure 6a shows the storage of refrigerant in the cabin evaporator. This occurs by opening the second expansion valve EXV2 with the second shut-off valve SOV2 open and the third shut-off valve SOV3 closed. Refrigerant is temporarily stored in the cabin evaporator 8-1. Fig. 6b shows the return of the temporarily stored refrigerant - process step c) - from the cabin evaporator 8-1 into the heat pump circuit by opening the third shut-off valve SOV3 with the second expansion valve EXV2 closed.

[0041] Fig. 7a and Fig. 7b shows a fifth embodiment of the invention in which the refrigerant storage means 16 is an additional component in the form of a liquid container. The switchable valve device 18 comprises a fourth expansion valve EXV4 or a fourth shut-off valve SOV4 with a small opening, which are arranged upstream of the refrigerant storage means 16, and a fifth shut-off valve SOV5 arranged downstream of the refrigerant storage means 16. The fourth expansion valve EXV5 or the fourth shut-off valve SOV4 is connected to the condenser outlet 4-o of the cabin condenser 4, and the fifth shut-off valve SOV5 is connected to the refrigerant collector inlet 14-i.

[0042] Fig. 7a shows the storage of refrigerant in the refrigerant storage medium 16 by opening the fourth expansion valve EXV4 or the fourth shut-off valve SOV4 with the fifth shut-off valve SOV5 closed - process step b). Fig. 7b shows the return of the refrigerant temporarily stored in the refrigerant storage medium 16 into the heat pump circuit by opening the fifth shut-off valve SOV5 when the fourth expansion valve EXV4 or the fourth shut-off valve SOV4 is closed.

[0043] Because the refrigerant storage medium 16 is an additional component, it can be specifically dimensioned for the intermediate storage of refrigerant. The internal volume and thus the maximum refrigerant filling quantity can thus be increased because two containers for refrigerant are available: the refrigerant collector 14 and the refrigerant storage medium 16. The refrigerant storage medium 16 is arranged in an area 24, e.g. near a line with hot liquid or in the engine compartment, in which the temperature is higher than the outside temperature, at least during operation of the heat pump arrangement HP. This facilitates the return of the refrigerant to the heat pump circuit and the return of the refrigerant can also take place at a higher suction pressure, since the higher temperature in area 24 of the refrigerant storage medium 16 also results in a higher saturation pressure in the refrigerant storage medium 16.

[0044] Fig. 8a and Fig. 8b show a sixth embodiment of the invention, which differs from the fifth embodiment according to Fig. 7a and Fig. 7b differs in that analogous to the second embodiment according to Fig. 4a and Fig. 4b, in method step b), refrigerant is continuously introduced into and removed from the refrigerant storage medium 16. The switchable valve device 18 comprises a fourth shut-off valve SOV4 in series with a first throttle FOT1, wherein the fourth shut-off valve SOV4 is connected to the condenser outlet 4-o of the cabin condenser 4 and the first throttle FOT1 is connected to the refrigerant storage medium 16. The switchable valve device 18 comprises a second throttle FOT2, which is connected downstream of the refrigerant storage medium 16, and the second throttle FOT2 is connected to the refrigerant collector inlet 14-i. Fig. 8a shows the continuous charging and discharging into / from the refrigerant storage medium by adjusting the opening degree of the fourth shut-off valve SOV4 and by the first and second throttles FOT1, FOT2. Fig. Figure 8b shows the emptying of the refrigerant storage tank by closing the fourth shut-off valve SOV4. List of reference symbols HP heat pump arrangement EXV1 first expansion valve EXV expansion valve device EXV-i valve inlet from EXV EXV-o valve output from EXV EXV2 second expansion valve EXV2-i valve inlet of EXV2 EXV2-o Valve output of EXV2 EXV3 third expansion valve EXV3-i valve inlet of EXV3 EXV3-o Valve output of EXV3 EXV BP Bypass expansion valve EXV4 fourth expansion valve SOV1 first shut-off valve SOV2 second shut-off valve SOV3 third shut-off valve SOV4 fourth shut-off valve SOV5 fifth shut-off valve FOT1 first throttle FOT2 second throttle DP1 double arrow in Fig. 1 DP2 double arrow in Fig. 2 2 compressor 2-i compressor inlet 2-o Compressor outlet 4 Cabin condenser 4-i condenser inlet 4-o Condenser outlet 6 outdoor heat exchangers 6-i outdoor heat exchanger inlet 6-o Outdoor heat exchanger outlet 8 Evaporator device 8-i evaporator inlet 8-o Evaporator outlet 8-1 Cabin evaporator 8-1-i cabin evaporator inlet 8-1-o Cabin evaporator outlet 8-2 Chiller 8-2-i Chiller inlet 8-2-o Chiller outlet 10 lockable line between 4 and EXV 12 Check valve 14 refrigerant collectors 14-i refrigerant receiver inlet 14-o Refrigerant receiver outlet 16 Refrigerant storage media 18 switchable valve device 20 Bypass line 22 internal heat exchanger 22-1 heat-absorbing part of 22 22-2 heat-emitting part of 22 24 Area of ​​elevated temperature around 16 30 Control

Claims

[1] Thermal management system for vehicles, comprising a heat pump arrangement (HP) and a controller (30) designed to operate the heat pump arrangement (HP) in different operating modes, the heat pump arrangement (HP) comprising: a compressor (2) with compressor inlet (2-i) and compressor outlet (2-o), a cabin condenser (4) having a condenser inlet (4-i) and a condenser outlet (4-o), wherein the compressor outlet (2-o) is connected to the cabin condenser inlet (4-i), an outdoor heat exchanger (6) having an outdoor heat exchanger inlet (6-i), an outdoor heat exchanger outlet (6-o) and a first expansion valve (EXV1), wherein the first expansion valve (EXV1) is arranged between the cabin condenser outlet (4-o) and the outdoor heat exchanger inlet (6-i), an evaporator device (8) with an evaporator inlet (8-i), an evaporator outlet (8-o) and an expansion valve device (EXV), wherein the expansion valve device (EXV) comprises a valve inlet (EXV-i) and a valve outlet (EXV-o), wherein the valve outlet (EXV-o) of the expansion valve device (EXV) is connected to the evaporator inlet (8-i) of the evaporator device (8), wherein the condenser outlet (4-o) of the cabin condenser (4) is connected to the valve inlet (EXV-i) of the expansion valve device (EXV) via a shut-off line (10), and wherein the outdoor heat exchanger outlet (6-o) is connected via a valve (12) to the valve inlet (EXV-i) of the expansion valve device (EXV), and a refrigerant collector (14) having a refrigerant collector inlet (14-i) and a refrigerant collector outlet (14-o), wherein the refrigerant collector inlet (14-i) is connected to the evaporator outlet (8-o) of the evaporator device (8), and wherein the refrigerant collector outlet (14-o) is connected to the compressor inlet (2-i), characterized by , that a refrigerant storage means (16) with a switchable valve device (18) is provided for the intermediate storage of refrigerant, that the refrigerant storage means (16) with the switchable valve device (18) is arranged between a first and a second position, that the first position is between the cabin condenser outlet (4-o) and the valve inlet (EXV-i) of the expansion valve device (EXV), and that the second position is between the evaporator outlet (8-o) and compressor inlet (2-i). [2] Thermal management system according to claim 1, characterized by that the refrigerant storage means (16) with the switchable valve device (18) is arranged between the cabin condenser outlet (4-o) and the refrigerant collector inlet (14-i). [3] Thermal management system according to one of the preceding claims, characterized bya bypass line (20) with a bypass expansion valve (EXV BP ), which is arranged between the compressor outlet (2-o) and refrigerant receiver inlet (14-i). [4] Thermal management system according to one of the preceding claims, characterized by , that the evaporator device (8) has a cabin evaporator (8-1) with a cabin evaporator inlet (8-1-i) and a cabin evaporator outlet (8-1-o) and a chiller (8-2) with a chiller inlet (8-2-i) and a chiller outlet (8-2-o), that the expansion valve device (EXV) comprises a second and third expansion valve (EXV2, EXV3), each with a valve inlet (EXV2-i, EXV3-i) and a valve outlet (EVX2-o, EXV3-o), that the valve outlet (EXV2-o) of the second expansion valve (EXV2) is connected to the cabin evaporator inlet (8-1-i), and that the valve outlet (EXV3-o) of the third expansion valve (EXV3) is connected to the chiller inlet (8-2-i). [5] Thermal management system according to one of the preceding claims, characterized by that the outdoor heat exchanger (6) is used as a refrigerant storage device (16), that the switchable valve device (18) comprises the first expansion valve (EXV1) and a first shut-off valve (SOV1), that the first shut-off valve (SOV1) is arranged between the outdoor heat exchanger outlet (6-o) and the refrigerant collector inlet (14-i), and that a second shut-off valve (SOV2) is arranged between the cabin condenser outlet (4-o) and the expansion valve device (EXV). [6] Thermal management system according to claim 4, characterized bythat the cabin evaporator (8-1) is used as a refrigerant storage means (16), that the switchable valve device (18) comprises the second expansion valve (EXV2) and a third shut-off valve (SOV3), and that the third shut-off valve (SOV3) is arranged between the cabin evaporator outlet (8-1-o) and the refrigerant collector inlet (14-i). [7] Thermal management system according to one of the preceding claims, characterized by that the refrigerant storage medium (16) is an additional component. [8] Thermal management system according to claim 7, characterized by that the refrigerant storage means (16) is arranged in a region (24) in which the temperature is higher than the outside temperature at least during operation of the heat pump arrangement. [9] Thermal management system according to claim 7 or 8, characterized bythat the switchable valve device (18) comprises a fourth expansion valve (EXV4) or a fourth shut-off valve (SOV4) which are connected upstream of the refrigerant storage means (16), and that the switchable valve device (18) comprises a fifth shut-off valve (SOV5) which is connected downstream of the refrigerant storage means (16). [10] Thermal management system according to claim 7 or 8, characterized by in that the switchable valve device (18) comprises a fourth shut-off valve (SOV4) in series with a first throttle (FOT1), wherein the fourth shut-off valve (SOV4) is connected to the condenser outlet (4-o) of the cabin condenser (4) and the first throttle (FOT1) is connected to the refrigerant storage means (16), and in that the switchable valve device (18) comprises a second throttle (FOT2) which is connected downstream of the refrigerant storage means (16). [11] Thermal management system according to one of the preceding claims, characterized byan internal heat exchanger (22) having a heat-emitting part (22-1) and a heat-absorbing part (22-2), wherein the heat-emitting part (22-1) is arranged between the external heat exchanger outlet (6-o) and the expansion valve device (EXV), and wherein the heat-absorbing part (22-2) is arranged between the refrigerant collector outlet (14-o) and the compressor inlet (2-i). [12] Method for operating a thermal management system according to one of the preceding claims, comprising the method steps: a) operating the heat pump arrangement for heating a vehicle cabin via the cabin condenser (4); characterized by b) temporarily storing a portion of the refrigerant in the refrigerant storage means (16) if the suction pressure of the compressor (2) is below the saturation pressure of the refrigerant at ambient temperature in the region of the refrigerant storage means (16), and c) Returning the temporarily stored refrigerant to the refrigerant circuit before the suction pressure of the compressor (2) rises above the saturation pressure of the refrigerant at ambient temperature in the area of ​​the refrigerant storage medium (16). [13] Method according to claim 12, characterized by that process step c) begins at the earliest when the suction pressure of the compressor (2) has exceeded its absolute minimum and begins to rise continuously. [14] Method according to claim 12 or 13, characterized by the process step: d) operating the heat pump assembly in a heat boost mode by passing a portion of the compressed refrigerant gas from the compressor outlet (2-o) via the bypass line (20) with the bypass expansion valve (EXV BD ) to the refrigerant receiver inlet (14-i) to increase the suction pressure of the compressor (2). [15] Method according to one of claims 12 to 14, characterized bythat the external heat exchanger (6) is used as a refrigerant storage means (16), that in method step b) by opening the first expansion valve (EXV1) with the first shut-off valve (SOV1) closed, refrigerant is temporarily stored in the external heat exchanger (6), and that in method step c) by opening the first shut-off valve (SOV1) with the first expansion valve (EXV1) closed, the temporarily stored refrigerant is taken back into the heat pump circuit. [16] Method according to one of claims 12 to 14, characterized by that the external heat exchanger (6) is used as a refrigerant storage means (16), and that in method step b) by adjusting the degree of opening of the first expansion valve (EXV1) and the first shut-off valve (SOV1) refrigerant is continuously temporarily stored in the external heat exchanger (6) and discharged therefrom again. [17] Method according to one of claims 12 to 14, characterized bythat the cabin evaporator (8-1) is used as a refrigerant storage means (16), that in method step b) refrigerant is temporarily stored in the cabin evaporator (8-1) by opening the second expansion valve (EXV2) with the third shut-off valve (SOV3) closed, and that in method step c) the temporarily stored refrigerant is taken back into the heat pump circuit by opening the third shut-off valve (SOV3) with the second expansion valve (EXV2) closed. [18] Method according to one of claims 12 to 14, characterized bythat an additional component is used as a refrigerant storage means (16), that in method step b) refrigerant is temporarily stored in the additional component (16) by opening the fourth expansion valve (EXV4) or the fourth shut-off valve (SOV4) when the fifth shut-off valve (SOV5) is closed, and that in method step c) the temporarily stored refrigerant is taken back into the heat pump circuit by opening the fifth shut-off valve (SOV5) when the fourth expansion valve (EXV4) or the fourth shut-off valve (SOV4) is closed. [19] Method according to one of claims 12 to 14, characterized bythat an additional component is used as refrigerant storage means (16), and that in method step b) by adjusting the degree of opening of the fourth expansion valve (EXV4) or the fourth shut-off valve (SOV4) and by the first and second throttles (FOT1, FOT2) refrigerant is continuously temporarily stored in the refrigerant storage means (16) and discharged therefrom again. [20] Method according to one of claims 12 to 19, characterized by , which uses CO2 as a refrigerant.

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