Refrigeration system with heat pump function for a motor vehicle with a single low-pressure side sensor device

Description

[0001] The invention relates to a refrigeration system according to the preamble of claim 1, in particular with a heat pump function, for a motor vehicle, wherein the refrigeration system comprises: a refrigerant compressor which is connectable or connected to a primary line; a directly or indirectly acting external heat exchanger which is arranged in the primary line; a first evaporator which is arranged in the primary line; a first directly or indirectly acting heat exchanger, in particular a chiller, which is arranged fluidically parallel to the evaporator; and a refrigerant collector arranged on the low-pressure side.

[0002] Such a refrigeration system is known, for example, from DE 10 2017 218 424 A1.

[0003] Refrigeration systems with a low-pressure side refrigerant collector that utilize both waste heat directly from electrical (drive) components via the additional heat exchanger, in particular a chiller, and ambient heat via an external heat exchanger are equipped with pressure / temperature sensors at various points in the refrigerant circuit according to DE 10 2018 201 165 B3. In particular, two or more sensor devices for measuring pressure and / or temperature are regularly provided on the low-pressure side of the refrigeration system. Further refrigeration systems are known from DE 10 2015 007 564 A1, the subsequently published DE 10 2019 135 056, DE 10 2018 201 945 A1, and DE 10 2018 213 232 A1. In particular, on the low-pressure side, a pressure / temperature sensor is arranged after the evaporator or after the further heat exchanger (chiller) as well as after the refrigerant collector.

[0004] The object underlying the invention is to provide a refrigeration system in which a simplified structure is achieved with essentially the same functionality.

[0005] This object is achieved by a refrigeration system having the features of patent claim 1 and by a motor vehicle having the features of patent claim 9.

[0006] Advantageous embodiments with useful further developments are specified in the dependent patent claims.

[0007] A refrigeration system, in particular with an optional heat pump function, for a motor vehicle is therefore proposed, the refrigeration system comprising: a refrigerant compressor which is connectable or connected to a primary line; a directly or indirectly acting external heat exchanger which is arranged in the primary line; a first evaporator which is arranged in the primary line; a first directly or indirectly acting heat exchanger, in particular a chiller, which is arranged fluidically parallel to the evaporator; and a refrigerant collector arranged on the low-pressure side, wherein downstream of the evaporator and the further heat exchanger, in particular a chiller, a single sensor device is arranged which is designed to detect the pressure and the temperature of the refrigerant on the low-pressure side of the refrigeration system.

[0008] By arranging a single sensor device for measuring pressure and temperature, a single sensor device can be omitted compared to conventional refrigeration systems, simplifying the design of the refrigeration system. It should be noted that the single sensor device can comprise a single pressure sensor and a single temperature sensor or can be designed as a combined pressure / temperature sensor.

[0009] In the refrigeration system, the only sensor device is located upstream of the refrigerant receiver. In other words, the only sensor device is located in front of the refrigerant receiver, in particular just before or directly in front of the refrigerant receiver. "Directly in front of the refrigerant receiver" can be understood as a distance that extends up to approximately 20 centimeters upstream of the refrigerant receiver.

[0010] The single sensor device can be arranged downstream of a branch in which an outlet-side line section of the evaporator and an outlet-side line section of the further heat exchanger, in particular the chiller, are connected to each other. In other words, the single sensor device is arranged downstream of a junction of the refrigerant lines of the evaporator and chiller.

[0011] The refrigeration system can have a control device configured to perform at least one of the following functions based on pressure and / or temperature values ​​detected by the single sensor device: monitoring a temporary, in particular short-term or long-term, overheating of the refrigerant to detect underfilling; monitoring the minimum suction pressure to protect against icing. Short-term overheating with associated underfilling, which usually lasts only a few seconds, is generally uncritical for the operation of the refrigeration system, whereas long-term overheating with associated underfilling of at least one to several minutes is detrimental and critical for the operation of the refrigeration system.

[0012] When monitoring and, if necessary, promptly compensating or reducing the temporary underfilling, an overheating condition can be taken into account. Such an overheating condition can occur, for example, in Load changes in the system towards a higher power requirement; low load when the evaporator is operated solely in cooling mode (AC mode); heat pump operation or reheat operation with excess heat.

[0013] When arranging the single sensor device downstream of the refrigerant receiver, a delay in the reduction of the overheating condition during regular system operation must be taken into account due to the transition from steady-state to at least temporarily dynamic (unsteady-state) operation of the refrigeration system in connection with the load change that has occurred and the incomplete release of additionally required refrigerant from the refrigerant receiver into the circuit. The process of supplying refrigerant from the receiver to the active system or the circuit itself is delayed. The greater the load change, the more pronounced and longer the time until regular, quasi-steady-state operation with an essentially constant refrigerant mass flow is restored.

[0014] In the refrigeration system with the only low-pressure side sensor device upstream of the refrigerant collector, the control device can be further configured to perform at least one of the following additional functions based on detected pressure and / or temperature values: Control of the evaporator and / or the additional heat exchanger, in particular the chiller, in an AC dual operation; control of the superheating of the evaporator when more cooling capacity is required from the additional heat exchanger, in particular the chiller; control of the superheating of the additional heat exchanger, in particular the chiller, when more cooling capacity is required from the evaporator.

[0015] If the single sensor device is located upstream of the refrigerant receiver, the functions described above regarding superheating can be implemented without any significant delay. Accordingly, monitoring and, if necessary, controlling temporary underfilling via the superheating state can be done very quickly and accurately.

[0016] In the case of the refrigeration system with the single low-pressure side sensor device upstream of the refrigerant collector, the control device can be set up to take into account at least one stored characteristic curve and / or at least one stored characteristic map, wherein the characteristic curve or the characteristic map comprise values ​​for determining prevailing pressure levels, in particular a suction pressure reduction, based on a pressure detected by the single sensor device and on a pressure loss contained in the characteristic curve or the characteristic map, which occurs downstream from the single sensor device up to the refrigerant compressor. The characteristic curve or the characteristic map serve in particular to achieve improved quality with regard to the determination or estimation of target variables that are set on the system side. The aim is that the respectively required orcurrent pressures can be determined and, if necessary, a low pressure limit can be estimated or predicted.

[0017] Furthermore, in the refrigeration system, the control device can be configured to detect underfilling, in particular by means of the evaluated refrigerant state, downstream of the refrigerant receiver, wherein a delaying effect of the refrigerant receiver is estimated or determined by means of a characteristic map and / or functions. It should be noted that underfilling detection is recorded more directly and thus more dynamically and possibly more sensitively by the sensor device arranged upstream of the refrigerant receiver, so that the described damping or delaying effect by the refrigerant receiver for setting a final refrigerant state in the refrigeration system should be modeled by means of a characteristic map and / or functions. In a simplified variant, a characteristic curve can alternatively be used.

[0018] The refrigeration system may further comprise: a secondary line which is or can be connected to the refrigerant compressor; and a further heat exchanger representing a heat source, acting directly or indirectly, in particular a heating register, which is arranged in the secondary line.

[0019] The refrigeration system may further comprise: a primary branch valve arranged between the refrigerant compressor and the external heat exchanger; and a secondary branch valve arranged between the refrigerant compressor and the further heat exchanger, in particular a heating register, representing a heat source.

[0020] A motor vehicle, in particular an at least partially electrically powered motor vehicle, may have a refrigeration system as described above. In an electric vehicle, the efficient operation of the refrigeration system can lead to electricity savings, thereby enabling a greater range of the electric vehicle. In particular, the refrigeration system presented here can monitor virtually all operating states of the refrigeration system even with only a single low-pressure sensor device for detecting pressure and temperature, just as if the refrigeration system had at least two low-pressure pressure / temperature sensors.

[0021] Further advantages and details of the invention will become apparent from the following description of embodiments with reference to the figures. Fig. 1 is a schematic and simplified circuit diagram of a refrigeration system for a motor vehicle, which falls outside the scope of the claim; Fig. 2a schematic and simplified circuit diagram of a refrigeration system for a motor vehicle.

[0022] In Fig. 1 An embodiment of a refrigeration system 10 for a motor vehicle is shown schematically and in simplified form, which is not part of the invention. The refrigeration system 10 comprises a refrigerant circuit 11, which can be operated both in refrigeration system mode (also called AC mode for short) and in heat pump mode. In the embodiment shown, the refrigeration system 10 comprises a refrigerant compressor 12, an external heat exchanger 18, an internal heat exchanger 20, an evaporator 22 and an accumulator or refrigerant collector 24. The external heat exchanger 18 can be designed as a condenser or gas cooler. In particular, the external heat exchanger 18 can be flowed through bidirectionally in the embodiment shown.

[0023] The evaporator 22 is shown here as an example of a front evaporator for a vehicle. The evaporator 22 also represents other possible evaporators in a vehicle, such as rear evaporators, which can be arranged parallel to one another in terms of flow. In other words, the refrigeration system 10 comprises at least one evaporator 22.

[0024] A shut-off valve A4 is located downstream of the compressor 12. An expansion valve AE2 is provided upstream of the evaporator 22.

[0025] For the purposes of this description, in the entire refrigerant circuit 11 of the refrigeration system 10, the section from the compressor 12 to the external heat exchanger 18, to the internal heat exchanger 20 and to the evaporator 22 is referred to as the primary line 14.

[0026] The refrigeration system 10 further comprises a heating register 26 (also referred to as a heating condenser or hot gas cooler). A shut-off valve A3 is arranged upstream of the heating register 26. A shut-off valve A1 is arranged downstream of the heating register 26. Furthermore, an expansion valve AE4 is arranged downstream of the heating register 26.

[0027] For the purposes of this description, the section of the entire refrigerant circuit of the refrigeration system 10 from the compressor 12 to the heating register 26, to the expansion valve AE4, and to a branch Ab2 is referred to as the secondary branch 16. The secondary branch 16 comprises a heating branch 16.1, which extends from the shut-off valve A3 via the heating register 26 to the shut-off valve A1. Furthermore, the secondary branch 16 comprises a reheat branch 16.2, which is fluidly connected upstream to the heating register 26 and downstream to the external heat exchanger 18. The secondary branch 16 or the reheat branch 16.2 flows into the primary branch 14 at a branch point Ab2.

[0028] The refrigeration system 10 includes a further evaporator or chiller 28. The chiller 28 is arranged in parallel flow with the evaporator 22. The chiller 28 can be used, for example, to cool an electrical component of the vehicle, but also to implement a water heat pump function by utilizing the waste heat from at least one electrical component. An expansion valve AE1 is connected upstream of the chiller 28.

[0029] The refrigeration system 10 can also include an electric heating element 30, which is embodied, for example, as a high-voltage PTC heating element. The electric heating element 30 serves as an additional heater for an air supply flow L directed into the vehicle interior. The electric heating element 30 can be housed together with the heating register 26 and the evaporator 22 in an air conditioning unit 32. The electric heating element 30 can be arranged downstream of the heating register 26.

[0030] In the Fig. 1 Check valves R1 and R2 are also visible. Furthermore, some high-pressure side sensors pT1, pT5, pT6 are shown for measuring the pressure and / or temperature of the refrigerant. Please note that the number of high-pressure side sensors and their arrangement are only shown as examples. In the example shown, combined pressure / temperature sensors pT1, pT5, and pT6 are shown as sensors. However, it is equally conceivable that separate sensors are used to measure pressure and temperature, and if necessary, they are arranged spatially separated from one another along the refrigerant lines.

[0031] The refrigeration system 10 can be operated in different modes, which are briefly described below.

[0032] In AC operation of the refrigerant circuit 11, the refrigerant compressed to high pressure flows from the refrigerant compressor 12 with the shut-off valve A4 open into the external heat exchanger 18. From there, it flows to the high-pressure section of the internal heat exchanger 20 and the fully open expansion valve AE3. Via a branch point Ab1, the refrigerant can flow to the expansion valve AE2 and into the interior evaporator 22 (evaporator section 22.1). In parallel or alternatively, the refrigerant can flow via a branch point Ab4 and the expansion valve AE1 into the chiller 28 (chiller section 28.1). From the evaporator 22 and / or the chiller 28, the refrigerant flows on the low-pressure side into the receiver 24 and through the low-pressure section of the internal heat exchanger 20 back to the compressor 12.

[0033] In AC operation, the heating branch 16.1 or the secondary branch 16 is shut off by means of the shut-off valve A3 so that hot refrigerant cannot flow through the heating register 26. To retrieve refrigerant from the inactive heating branch 16.1, the shut-off element A5, designed as a shut-off valve, can be opened so that the refrigerant can flow towards the collector 24 via the shut-off element A5 and the check valve R2, with the shut-off element A2 simultaneously closed.

[0034] In heating mode of the refrigerant circuit 11, the shut-off valve A4 is closed and the shut-off valve A3 is opened so that hot refrigerant can flow into the heating branch 16.1.

[0035] To carry out the heating function by means of the chiller 28 to implement water heat pump operation, the refrigerant compressed by the refrigerant compressor 12 flows through the open shut-off valve A3 into the heating register 26. At the heating register 26, heat is transferred to an inlet air flow L led into the vehicle interior. The refrigerant then flows through the open shut-off valve A1 and the branch point Ab1. It is expanded by means of the expansion valve AE1 in the chiller 28 to absorb waste heat from the electrical and / or electronic components arranged in a coolant circuit 28.2. During this heating function, the expansion valves AE3 and AE4 are closed, the shut-off valve A5 is closed, and the shut-off valve A2 is open. In this case, refrigerant removed from a bidirectional branch 14.1 orsucked from the primary line 14 and fed to the collector 24 via the check valve R2.

[0036] To perform the heating function using the external heat exchanger 18 as a heat pump evaporator, the refrigerant compressed by the refrigerant compressor 12 flows through the open shut-off valve A3 into the heating register 26 to release heat to a supply air flow L. It is then expanded through the open shut-off valve A1 by means of the expansion valve AE3 into the external heat exchanger 18 to absorb heat from the ambient air. The refrigerant then flows via a heat pump return branch 15 to the collector 24 and back to the refrigerant compressor 12. The expansion valves AE1, AE2, and AE4, as well as the shut-off valve A5, remain closed.

[0037] An indirect delta connection can be realized by expanding the refrigerant compressed by the refrigerant compressor 12 into the chiller 28 by means of the expansion valve AE1 when the shut-off valve A1 is open. At the same time, no mass flow is generated on the coolant side, i.e., in the coolant circuit 28.2. For example, the fluid used as coolant, such as water or a water-glycol mixture, remains on the coolant side of the chiller 28, or the chiller 28 is not actively flowed through by coolant. The expansion valves AE2, AE3, and AE4 remain closed in this switching variant.

[0038] During reheating or reheating operation, the supply air flow L supplied to the vehicle interior is first cooled and thus dehumidified by means of the evaporator 22. With the heat transferred to the refrigerant through evaporation and dehumidification, as well as the heat supplied to the refrigerant via the compressor 12, the supply air flow L can be completely or at least partially reheated by means of the heating register 26.

[0039] For this purpose, the refrigeration system 10, in particular the air conditioning unit 32, has adjustable, in particular controllable and pivotable, temperature flaps 34 between the evaporator 22 and the heating register 26. In the example shown, a left and a right temperature flap 34L and 34R (in Figur 1 (shown schematically). The temperature dampers 34L, 34R can be adjusted or pivoted between an open position, referred to as the 100% position, and a closed position, referred to as the 0% position. Alternatively, it is also possible to install the temperature dampers 34R, 34L downstream of the heating register 26.

[0040] In the 100% position, the entire supply air flow L flowing through the evaporator 22 is guided over the heating register 26 and heated before it can flow into the passenger compartment of the vehicle. In the 0% position, the entire supply air flow L flowing through the evaporator 22 flows in the bypass around the heating register 26 without heating and thus without heat absorption into the passenger compartment.

[0041] In an x-position of the temperature flaps 34L and 34R with 0% < x < 100%, these temperature flaps are only partially open, so that only a partial air flow of the supply air flow L flowing through the evaporator 22 is guided over the heating register 26. This heated partial air flow can then be mixed with the remaining, cooled and dehumidified partial air flow. The supply air flow L heated in this way is fed into the passenger compartment of the vehicle. For example, a 50% position indicates that the temperature flaps 34R and 34L are only half open, i.e., 50%.

[0042] On the low-pressure side of the refrigeration system 10, in particular downstream of the evaporator 22 and downstream of the chiller 28, a single sensor device pT2 is arranged. In the example of the Fig. 1 The sensor device pT2 is arranged downstream of the refrigerant collector 24. In particular, the sensor device pT2 is provided between the refrigerant collector 24 and the internal heat exchanger 20.

[0043] The evaporator 22 and the chiller 28 have a respective outlet-side or downstream section of the respective evaporator section 22.1 or chiller section 28.1, which are connected to each other at the branch Ab2. The only sensor device pT2 on the low-pressure side is provided downstream of the branch Ab2. This ensures that, regardless of whether refrigerant flows through the evaporator 22 or the chiller 28 alone or in combination, the pressure and temperature of the refrigerant on the low-pressure side can be detected. In other words, the only sensor device pT2 is arranged between the branch Ab2 and the internal heat exchanger 20 (if present) or the refrigerant compressor 12.

[0044] Fig. 2 shows an inventive arrangement of the single low-pressure-side sensor device pT2. The sensor device pT2 is arranged upstream of the refrigerant collector 24. The sensor device pT2 is arranged directly in front of the refrigerant collector 24. The distance between the sensor device pT2 and the refrigerant collector can be up to 20 centimeters, for example.

[0045] The sensor device pT2 is in the example of Fig. 2 also arranged downstream of the evaporator 22 and the chiller 28. In particular, the sensor device pT2 is arranged downstream of the branch Ab2, where the evaporator section 22.1 and the chiller section 28.1 meet. In other words, the sensor device pT2 is arranged between the branch Ab2 and the refrigerant collector 24.

[0046] In both examples of Fig.1 and 2The refrigeration system 10 has a control device 50 configured to detect the various operating states of the refrigeration system 10, which have been described above by way of example, but in particular to control or regulate them based on the input values ​​and target variables. The control device 50 can, in particular, receive and process sensor data, calculate and / or estimate further operating parameters, and control the refrigerant compressor or valve devices and the like of the refrigeration system.

[0047] Taking into account the structural design with a single low-pressure side sensor device pT2, the control device 50 can be configured to perform at least one of the following functions based on detected pressure and / or temperature values ​​from the single low-pressure side sensor device pT2: monitoring of overheating, which in systems with a refrigerant receiver 24 arranged on the low pressure side is equivalent to an underfill, which in turn can occur either temporarily or permanently; and / or monitoring of the minimum suction pressure for icing protection.

[0048] When monitoring and, if necessary, reducing temporary overheating, an underfilling condition can be taken into account. Such an overheating and thus underfilling condition can occur, for example, in Load changes in the system towards a higher power requirement; low load when the evaporator is operated solely in cooling mode (AC mode); heat pump operation or reheat operation with excess heat.

[0049] In this case, when the single sensor device pT2 is arranged downstream of the refrigerant collector 24 ( Fig. 1 ) due to the transition from stationary to at least temporarily dynamic (transient) operation of the refrigeration system 10 in connection with the load change that has occurred and the incomplete release of additionally required refrigerant from the refrigerant collector 24 into the circuit, a delay in the reduction of the overheating state during regular system operation must be taken into account. The process of supplying refrigerant from the collector 24 to the active system or the circuit 11 itself is delayed. The greater the load change, the more pronounced or longer the time period until regular, quasi-stationary operation is restored, with an essentially constant refrigerant mass flow.

[0050] In the refrigeration system 10 with the only low-pressure side sensor device pT2 upstream of the refrigerant collector 24 ( Fig. 2 ), the control device 50 can be further configured to perform at least one of the following additional functions based on detected pressure and / or temperature values: Control of the evaporator 22 and / or the further heat exchanger, in particular chiller 28, in an AC dual operation; control of the superheating of the evaporator 22 when more cooling capacity is required at the further heat exchanger, in particular chiller 28; control of the superheating of the further heat exchanger, in particular chiller 28, when more cooling capacity is required at the evaporator 22.

[0051] If the only sensor device pT2 is located upstream of the refrigerant receiver 24 ( Fig. 2 ), the functions described above regarding superheating can be implemented without any significant delay. Accordingly, monitoring and, if necessary, regulation of temporary underfilling via the superheating state can be carried out very quickly and precisely. In extreme cases, such as persistent overheating measured at greater than 5K, and unsuccessful controller intervention to correct this deviation from standard operating conditions, the refrigeration system 10 will shut down.

[0052] In the refrigeration system 10 with the only low-pressure side sensor device pT2 upstream of the refrigerant collector 24 ( Fig. 2 ), the control device 50 can be configured to take into account at least one stored characteristic map, wherein the characteristic map comprises values ​​for determining a suction pressure reduction based on a pressure detected by the single sensor device and on a pressure loss contained in the characteristic map, which occurs downstream from the single sensor device pT2 to the refrigerant compressor 12.

[0053] Furthermore, in the refrigeration system 10, the control device 50 can be configured to detect an underfilling downstream of the refrigerant collector 24, wherein a delaying effect of the refrigerant collector 24 is estimated by means of a characteristic map and / or by means of functions. It should be noted that an underfilling detection can be carried out with the sensor device pT2 ( Fig. 2) is detected more dynamically and possibly more sensitively, so that the described damping or delaying effect by the downstream refrigerant collector 24 should be modeled by means of a characteristic map and / or functions.

[0054] Using the refrigeration system 10 presented here with a single low-pressure sensor device pT2, at least one pressure-temperature sensor can be eliminated compared to known configurations of refrigeration systems for motor vehicles, which has a positive impact on the costs, packaging requirements, and weight of such a refrigeration system. Furthermore, despite the use of a single low-pressure sensor device pT2, it is possible to represent all essential functions or to provide them via the control device 50 of the refrigeration system 10.

Claims

1. Refrigeration system (10) with a heat pump function for a motor vehicle, wherein the refrigeration system (10) comprises: a refrigerant compressor (12), which is connectable or connected to a primary line (14); a directly or indirectly acting external heat exchanger (18), which is arranged in the primary line (14); a first evaporator (22), which is arranged in the primary line (14); a first directly or indirectly acting heat exchanger, in particular a chiller (28), which is arranged fluidically parallel to the evaporator (22); and a refrigerant collector (24) arranged on the low-pressure side, wherein a single sensor apparatus (pT2) is arranged downstream of the evaporator (22) and the first heat exchanger, in particular the chiller (28), which sensor apparatus is configured to detect the pressure and the temperature of the refrigerant on the low-pressure side of the refrigeration system (10), characterized in that the single sensor apparatus (pT2) is arranged upstream of the refrigerant collector (24) and directly in front of it.

2. Refrigeration system (10) according to claim 1, characterized in that the single sensor apparatus (pT2) is arranged downstream of a branch (Ab2), in which an outlet-side line section (22.1) of the evaporator (22) and an outlet-side line section (28.1) of the further heat exchanger, in particular the chiller (28), are connected to one another.

3. Refrigeration system (10) according to any one of the preceding claims, characterized in that it has a control apparatus (50) which is configured to carry out at least one of the following functions based on detected pressure and / or temperature values from the single sensor apparatus (pT2): monitoring temporary, in particular short-term or long-term, overheating of the refrigerant for recognizing underfilling; monitoring the minimum suction pressure for anti-icing protection.

4. Refrigeration system (10) according to claim 3, characterized in that the control apparatus (50) is configured to carry out at least one of the following further functions based on detected pressure and / or temperature values from the single sensor apparatus (pT2) arranged upstream of the refrigerant collector (24): regulating the evaporator (22) and / or the additional heat exchanger, in particular a chiller (28), in an AC dual operation; regulating the overheating of the evaporator (22) if more cooling power is required at the additional heat exchanger, in particular the chiller (28); regulating the overheating of the additional heat exchanger, in particular the chiller (28), if more cooling power is required at the evaporator (22).

5. Refrigeration system (10) according to claim 3 or 4, characterized in that the control apparatus (50) is configured to take into consideration at least one stored characteristic curve and / or at least one stored characteristic diagram, wherein the characteristic curve or the characteristic diagram comprises values for determining current pressure levels, in particular a suction pressure control, based on a pressure detected by the single sensor apparatus and a pressure loss contained in the characteristic curve or in the characteristic diagram, which occurs downstream of the single sensor apparatus (pT2) to the refrigerant compressor (12).

6. Refrigeration system (10) according to claim 5, characterized in that the control apparatus (50) is further configured to recognize underfilling downstream of the refrigerant collector (24), wherein a delaying effect of the refrigerant collector (24) is estimated or determined by means of a characteristic diagram and / or by means of functions.

7. Refrigeration system (10) according to any one of the preceding claims, <b>characterized in that it further comprises: a secondary line (16), which is connectable or connected to the refrigerant compressor (12); and a further directly or indirectly acting heat exchanger, representing a heat source, in particular a heating register (26), which is arranged in the secondary line (16).

8. Refrigeration system (10) according to claim 7, characterized in that it further comprises: a primary line valve (A4) arranged between the refrigerant compressor (12) and the external heat exchanger (18); a secondary line valve (A3) arranged between the refrigerant compressor (12) and the further heat exchanger, in particular a heating register (26), representing a heat source.

9. Motor vehicle, in particular at least partially electrically powered motor vehicle, with a refrigeration system (10) according to any one of the preceding claims.