WO2023110217A1

WO2023110217A1 - Refrigeration circuit for a motor vehicle, and method for operating a refrigeration circuit

Info

Publication number: WO2023110217A1
Application number: PCT/EP2022/080962
Authority: WO
Inventors: Michael Steffen
Original assignee: Mercedes-Benz Group AG
Priority date: 2021-12-14
Filing date: 2022-11-07
Publication date: 2023-06-22

Abstract

The invention relates to a refrigeration circuit (10) for a motor vehicle, through which refrigeration circuit a fluid (12) can flow, with an ejector (14) which has a suction side (16), a driving side (18) and an outlet side (20), via which the fluid (12) can be discharged from the ejector (14), wherein the fluid (12) which is discharged from the ejector (14) can be introduced into the ejector (14) via the suction side (16) and the driving side (18), with at least one first heat exchanger element (34) which is configured as an evaporator (32) and via which heat (36) from a second fluid (38) can be fed to the refrigeration circuit (10), and with a second heat exchanger element (40) which can be operated as a condenser (42), as a result of which heat (44) from the refrigeration circuit (10) can be discharged to a third fluid (46) via the second heat exchanger element (40), wherein the fluid (12) which flows through the refrigeration circuit (10) can be conducted from the outlet side (20) of the ejector (14) via the heat exchanger elements (34, 40) to the suction side (16) of the ejector (14).

Description

Refrigeration circuit for a motor vehicle and method for operating a refrigeration circuit

The invention relates to a refrigeration circuit for a motor vehicle according to the preamble of patent claim 1. The invention also relates to a method for operating a refrigeration circuit through which a fluid can flow for a motor vehicle according to the preamble of patent claim 10.

DE 10 2007 001 878 B4 discloses an ejector refrigeration cycle device including a compressor for compressing and discharging a refrigerant, a radiator for radiating heat of the high-temperature and high-pressure refrigerant discharged from the compressor, and a branch portion for branching a refrigerant flow downstream of the radiator into a first flow and a second stream. The ejector refrigerant cycle device includes an ejector that includes a nozzle portion for decompressing and expanding the refrigerant of the first flow from the branch portion, and a refrigerant suction port from which the refrigerant is sucked by a high-speed flow of the refrigerant jetted from the nozzle portion. In addition, the ejector refrigerant cycle device includes a decompression device for decompressing and expanding the refrigerant of the second flow from the branch portion, and an evaporator for evaporating the refrigerant downstream of the decompression device, the evaporator having a refrigerant outlet connected to the refrigerant suction port of the ejector.

The object of the present invention is to create a refrigeration circuit for a motor vehicle and a method for operating a refrigeration circuit for a motor vehicle, so that the refrigeration circuit can be operated particularly advantageously. This object is achieved according to the invention by a refrigeration circuit for a motor vehicle having the features of patent claim 1 and by a method for operating a refrigeration circuit for a motor vehicle having the features of patent claim 10 . Advantageous configurations with expedient developments of the invention are specified in the remaining claims.

A first aspect of the invention relates to a refrigeration circuit for a motor vehicle. The motor vehicle is preferably designed as a motor vehicle, in particular as a passenger car, utility vehicle or truck, or as a passenger bus or motorcycle. The motor vehicle preferably includes the refrigeration circuit in its fully manufactured state.

A fluid can flow through the refrigeration cycle. The fluid can in particular be referred to as a refrigerant or be designed as the refrigerant. The refrigeration cycle can in particular be referred to as a refrigeration cycle. The refrigeration circuit can be understood in particular as a compression refrigeration machine.

The refrigeration circuit has at least one ejector through which the fluid can flow, which includes a suction side, a drive side and an outlet side. The fluid can be discharged from the ejector via the outlet side, with the fluid discharged from the ejector via the outlet side and flowing through the refrigeration circuit in one direction of flow, in particular bypassing the ejector, being able to be introduced into the ejector via the suction side and/or the drive side. In other words, the ejector is arranged in the refrigeration circuit, wherein the fluid introduced into the ejector via the suction side and/or the drive side and flowing through the ejector can be discharged via the outlet side from the ejector and then as a result of flowing through the refrigeration circuit in the direction of flow be returned to the suction side and/or the drive side and thus reintroduced into the ejector. In other words, the fluid in the refrigeration circuit can be recirculated, with the fluid flowing through the ejector being able to be fed to the ejector via the suction side and the drive side or introduced into the ejector and discharged from the ejector via the outlet side for recirculation.

The ejector can be understood in particular as a jet pump, by means of which a vacuum or negative pressure can be generated inside the ejector, in particular by means of a Venturi nozzle. In particular, the ejector can be referred to as a vacuum component. Preferably, a pressure of the fluid introduced into the ejector via the drive side, in particular immediately upstream of the ejector or when the fluid enters the ejector, is at a higher pressure than the fluid introduced into the ejector via the suction side, in particular directly upstream of the ejector or at the Entry into the ejector. The fluid introduced into the ejector via the drive side can be accelerated or expanded in the ejector. The fluid can be accelerated or expanded by means of the venturi nozzle, which is referred to in particular as a venturi tube and which can be arranged inside the ejector.

As a result of the acceleration of the fluid, the pressure of the fluid within the ejector, in particular in relation to the pressure of the fluid introduced into the ejector via the drive side, can be particularly reduced. In other words, a pressure at a narrowest cross section of the Venturi nozzle is lower than a pressure of the fluid at an inlet of the Venturi nozzle. The acceleration of the fluid or the reduction of the pressure can be brought about by providing a narrowed flow cross section within the ejector or the Venturi nozzle. The narrowed flow cross section can thus be smaller than a flow cross section when the fluid enters the venturi nozzle.

The pressure inside the ejector is preferably reduced in such a way that the pressure inside the ejector is lower than a pressure of the fluid introduced into the ejector via the suction side, in particular directly upstream of the ejector or when it enters the ejector. Thus, there is a negative pressure within the ejector, based on the suction side and/or the drive side and/or the outlet side. As a result, a suction effect can be achieved, as a result of which the fluid flowing through the fluid circuit can be sucked in and thus sucked or introduced into the ejector via the suction side. In other words, there is a pressure difference within the ejector relative to the outlet side, by means of which the fluid can be introduced or sucked in via the suction side.

The ejector is preferably designed as a, in particular purely, passive component. This means that preferably no electrical energy, in particular for operating the ejector, is supplied to the ejector during operation of the refrigeration cycle. The refrigeration circuit has at least one first heat transfer element, through which the fluid can flow and designed as an evaporator, via which heat from a second fluid can be supplied to the refrigeration circuit. In other words, the first heat transfer element is arranged in the refrigeration cycle, heat from the second fluid being able to be supplied to the fluid flowing through the first heat transfer element.

The second fluid can be different from the first fluid. Preferably the second fluid is air. The fluid can in particular be referred to as the first fluid.

The first heat transfer element preferably has a first flow area through which the fluid can flow and a second flow area, in particular spaced apart from the first flow area, through which the second fluid can flow or around. The flow areas are preferably not fluidically connected to one another. Thus, the fluid flowing through the first flow area cannot get into the second flow area or the second fluid flowing through the second flow area cannot get into the first flow area. Heat can be removed from the second fluid via the first heat transfer element, it being possible for the heat removed from the second fluid to be supplied to the first fluid and thus to the refrigeration circuit via the first heat transfer element. In other words, the first fluid or the refrigeration circuit can be heated by the second fluid via the first heat transfer element and the second fluid can be cooled by the fluid or the refrigeration circuit via the first heat transfer element.

The fact that the first heat transfer element is designed as the evaporator can be understood in particular as meaning that at least part of the fluid flowing through the first heat transfer element can be vaporized as a result of the heat supplied by the second fluid via the first heat transfer element. In other words, at least part of the fluid entering the first heat transfer element is liquid, with at least part of the liquid part of the fluid or at least part of the fluid flowing through the first heat transfer element being transferred by means of the first heat transfer element as a result of the flow from the second fluid to the fluid supplied heat can be evaporated. Thus, a proportion of a gas phase of the fluid, referred to in particular as the gas proportion, can be higher when it exits the first heat transfer element than when it enters the first heat transfer element. For example, the fluid entering the first heat transfer element can be completely liquid or can be completely in a liquid phase. For example, the fluid flowing through the first heat transfer element can be completely evaporated, as a result of which the fluid can be present completely in the gas phase or as a gas when it exits the first heat transfer element.

The first heat transfer element can be provided to cool an interior of the motor vehicle, referred to in particular as a vehicle interior or cabin. In particular, this can be referred to as cabin cooling. Thus, in its fully manufactured state, the motor vehicle can have the interior, which can be cooled via the first heat transfer element.

For example, the second fluid, referred to in particular as cooling air, is air. The second fluid can be cooled by the fluid or the refrigeration circuit via the first heat transfer element, it being possible for the cooled second fluid or the cooling air to be introduced into the interior for cooling the interior.

Alternatively, the second fluid can be a coolant, with the motor vehicle having a cooling circuit through which the second fluid can flow and in particular referred to as an air conditioning cooling circuit when the motor vehicle is in the fully manufactured state, by means of which the vehicle interior can be cooled. For example, by means of the refrigeration cycle, air of the motor vehicle, referred to in particular as cooling air, can be cooled, it being possible for the cooling air to be introduced into the interior.

The refrigeration circuit has at least one second heat transfer element through which the fluid can flow and which is formed separately from the first heat transfer element, in particular at a distance from the first heat transfer element, which can be operated as a condenser, as a result of which heat from the refrigeration circuit can be dissipated to a third fluid via the second heat transfer element. In other words, via the second heat transfer element, heat of the fluid flowing through the second heat transfer element can be dissipated from the fluid and from the third fluid be supplied. In other words, the fluid or the refrigeration circuit can be cooled by the third fluid via the second heat transfer element.

For example, the second heat transfer element has a third flow region through which the fluid can flow and a fourth flow region through which the third fluid can flow, in particular spaced apart from the third flow region. The third and fourth flow areas are preferably not fluidly connected to one another. Thus, the fluid flowing through the third flow area cannot get into the fourth flow area or the third fluid flowing through the fourth flow area cannot get into the third flow area.

The third fluid is preferably a different fluid from the fluid. The third fluid can be different than the second fluid, or the third and second fluid can be the same or identical. Preferably the third fluid is air. The second flow area and the fourth flow area are preferably not fluidically connected to one another. Alternatively, the second and the fourth flow area can be fluidically connected to one another or can be connectable.

The fact that the second heat transfer element can be operated as the condenser can be understood in particular as meaning that at least part of the fluid flowing through the second heat transfer element can be condensed as a result of the heat removed from the fluid to the third fluid via the second heat transfer element. In other words, at least part of the fluid entering the second heat transfer element is gaseous, with at least part of the gaseous fluid flowing through the second heat transfer element being liquefiable by means of the second heat transfer element or as a result of the heat given off by the fluid to the third fluid.

Thus, a portion of a liquid phase of the fluid, referred to in particular as the liquid portion, can be greater when the fluid exits the second heat transfer element than when the fluid enters the second heat transfer element. In other words, the proportion of gas when the fluid exits the second heat transfer element can be lower than when the fluid enters the second heat transfer element. When entering the second heat transfer element, the fluid can only be present in the gas phase and thus completely exist as a gas. When exiting the second heat transfer element, the fluid can only be in the liquid phase or can be completely liquid.

Preferably the third fluid is air. The refrigeration circuit can thus be cooled by means of the air or heat can be dissipated from the fluid or the refrigeration circuit to the air via the second heat transfer element.

Preferably, the third fluid is ambient air. This means that the air or the ambient air from an area surrounding the motor vehicle is introduced into the motor vehicle and is fed to the second heat transfer element, for example via a feed device, as a result of which the air or the third fluid flows around or through the second heat transfer element. The third fluid can then be discharged from the motor vehicle to the environment. Heat from the fluid or from the refrigeration circuit can thus be dissipated to the surroundings of the motor vehicle via the third fluid.

The third fluid is preferably not routed through the vehicle interior. This means that the third fluid supplied to the second heat transfer element is not introduced into the interior before and/or after it flows around or through the second heat transfer element.

Since heat from the refrigeration circuit can be dissipated to the surroundings of the motor vehicle via the second heat transfer element, the second heat transfer element can be referred to in particular as an outer heat transfer element. The second heat transfer element can in particular be referred to as an outside heat exchanger (OHX).

The refrigeration circuit has at least one third heat transfer element through which the fluid can flow and which is formed separately from the heat transfer elements, in particular at a distance from the heat transfer elements, which is embodied as an evaporator, whereby heat from a fourth fluid can be supplied to the refrigeration circuit via the third heat transfer element. In other words, heat can be dissipated from the fourth fluid via the third heat transfer element, with the heat dissipated via the third Heat transfer element can be fed to the refrigeration circuit or to the fluid flowing through the third heat transfer element. In other words, the fluid circuit or the fluid can be heated by the fourth fluid via the third heat transfer element or the fourth fluid can be cooled by the refrigeration circuit or the fluid via the third heat transfer element.

For example, the third heat transfer element has a fifth flow area through which the fluid can flow and a sixth flow area through which the fourth fluid can flow or around. The fifth flow area and the sixth flow area are preferably not fluidly connected to one another. Thus, the fluid flowing through the fifth flow area cannot get into the sixth flow area or the fourth fluid flowing around or through the sixth flow area cannot get into the fifth flow area. The fourth fluid can be different from the fluid and/or the second fluid and/or the third fluid. Preferably the fourth fluid is a coolant.

The fact that the third heat transfer element is designed as an evaporator can be understood in particular as meaning that at least part of the fluid flowing through the third heat transfer element can be evaporated as a result of the heat supplied by the fourth fluid via the third heat transfer element. In other words, at least part of the fluid entering the third heat transfer element is liquid, with at least part of the liquid part of the fluid or at least part of the fluid flowing through the third heat transfer element being supplied by the third heat transfer element as a result of the fluid supplied to the fluid from the fourth Heat is evaporable. The gas content of the fluid can thus be higher when it exits the third heat transfer element than when it enters the third heat transfer element. For example, the fluid entering the third heat transfer element can be completely liquid or can be completely in a liquid phase. For example, the fluid flowing through the third heat transfer element can be completely evaporated, as a result of which the fluid can be present completely in the gas phase or as a gas when it exits the third heat transfer element. In order to operate the refrigeration circuit particularly advantageously, in particular by means of the ejector, particularly efficiently and/or with a particularly high refrigerating capacity, it is provided according to the invention that the first and the second heat transfer element are fluidically connected to the suction side of the ejector in such a way that the fluid flowing through the refrigeration circuit in the flow direction can be guided from the outlet side of the ejector via the first and the second heat transfer element to the suction side of the ejector and can be introduced into the ejector via the suction side. In other words, the first and the second heat transfer element are arranged in the fluid flow in relation to a fluid flow of the fluid running in the flow direction, in particular bypassing the ejector, from the outlet side of the ejector to the suction side of the ejector, whereby the fluid flow via the first and the second heat transfer element.

In addition, it is provided according to the invention that the second heat transfer element can be operated as the condenser in a first operating mode of the refrigeration circuit and can be operated as an evaporator in a second operating mode of the refrigeration circuit that differs from the first operating mode, whereby the refrigeration circuit receives heat from the third via the second heat transfer element Fluid can be supplied. In other words, the refrigeration circuit can be switched between the two operating modes, wherein in the first operating mode heat from the refrigeration circuit can be dissipated to the third fluid via the second heat transfer element and heat from the third fluid can be supplied to the refrigeration circuit via the second heat transfer element in the second operating mode .

In the second operating mode, heat can be removed from the third fluid flowing through or around the second heat transfer element via the second heat transfer element, wherein the removed heat can be supplied via the second heat transfer element to the fluid flowing through the second heat transfer element. In other words, in the second operating mode, the fluid flowing through the second heat transfer element and thus the refrigeration circuit can be heated by the third fluid flowing through or around the second heat transfer element. Thus, in the second operating mode, heat referred to in particular as ambient heat can be absorbed from the ambient air into the fluid or into the refrigeration circuit.

The fact that the second heat transfer element can be operated or is operated as an evaporator can be understood in particular to mean that at least part of the fluid flowing through the second heat transfer element can be evaporated as a result of the heat supplied by the third fluid via the second heat transfer element. In other words, at least part of the fluid entering the second heat transfer element is liquid, with at least part of the liquid part of the fluid or at least part of the fluid flowing through the second heat transfer element being supplied by the second heat transfer element as a result of the fluid supplied to the fluid from the third Heat is evaporable. Thus, the gas content of the fluid when it exits the second heat transfer element can be higher than when it enters the second heat transfer element. For example, the fluid entering the second heat transfer element can be completely liquid or can be completely in a liquid phase. For example, the fluid flowing through the second heat transfer element can be completely evaporated, as a result of which the fluid can be present completely in the gas phase or as a gas when it exits the second heat transfer element.

The invention is based in particular on the following findings and considerations: A conventional refrigeration cycle can have an ejector, but the conventional refrigeration cycle cannot have a heat pump function, ie the conventional refrigeration cycle cannot be operated as a heat pump. Thus, no absorption of ambient heat and/or waste heat from the motor vehicle, in particular cooling circuit waste heat, can be provided in the conventional refrigeration circuit. Alternatively, a conventional refrigeration circuit can have the heat pump function and can therefore be operated as a heat pump, with the conventional refrigeration circuit usually not having an ejector. A conventional refrigeration circuit usually cannot be operated as a heat pump, which means that the conventional refrigeration circuit cannot have any heat pump functionality.

In contrast, the refrigeration circuit according to the invention has the ejector and can, in particular in the first and/or the second operating mode, as a heat pump operate. Thus, the refrigeration circuit according to the invention has the heat pump function. The refrigeration circuit can be operated particularly advantageously, in particular particularly efficiently, by the ejector, in particular in the second operating mode or in heat pump operation.

Due to the ejector, a pressure of the fluid, referred to in particular as the suction pressure, can be different from one another in respective partial regions of the refrigeration cycle that are different from one another. A first of the subregions can be connected to the suction side of the ejector fluid, wherein the first subregion can be arranged, in particular directly, upstream of the ejector or the suction side. A second of the subregions can be fluidly connected to the drive side of the ejector and can be arranged, in particular directly, upstream of the ejector or the drive side. Due to the different pressure or suction pressure level in the partial areas, the refrigeration circuit can be operated in such a way that a refrigeration capacity of the refrigeration circuit can be particularly increased. Alternatively or additionally, a pressure of the fluid can be particularly increased by means of the ejector, in particular directly downstream of the ejector or the outlet side. As a result, the refrigeration circuit can be operated particularly efficiently, in particular because the suction pressure on the outlet side or at the outlet of the ejector can be higher than in a conventional refrigeration circuit that has no ejector. This can be achieved in particular in that a compressor provided for conveying the fluid through the refrigeration circuit or for compressing the fluid can be operated with a particularly low power consumption. For example, a speed of the compressor can be kept particularly low, which can in particular be referred to as a reduction in speed.

Furthermore, the refrigeration circuit according to the invention can be operated as a heat pump, in particular in the first and/or second operating mode. Heat can be absorbed in particular via the second heat transfer element and/or the first heat transfer element, it being possible for the heat absorbed to be released to the interior for heating the interior of the motor vehicle. The refrigeration circuit can thus be provided or used to heat the interior. As a result, the interior can be heated particularly efficiently. For example, the energy requirement of the motor vehicle, in particular for heating, can be kept particularly low. The fact that the pressure of the fluid, in particular directly downstream of the ejector or the outlet side, can be particularly increased by means of the ejector Ejector would not have, in particular with the result that the compressor sees a higher intake pressure and thus works more efficiently or particularly efficiently.

The refrigeration circuit preferably has at least one electronic computing device, by means of which it is possible to switch or switch back and forth between the first and the second operating mode. It can be continuously transferred or switched over from one operating mode to the other by continuous control interventions, which can be used in particular due to changing external boundary conditions.

The refrigeration circuit preferably has at least one, in particular electrical or mechanical, compressor through which the fluid can flow, for conveying the fluid through the refrigeration circuit. The electric compressor can in particular be understood to mean that the compressor can be driven electrically to compress the fluid. The compressor can in particular be referred to as a compressor.

The compressor is preferably arranged on the outlet side of the ejector. This can in particular be understood to mean that the compressor is arranged close, in particular in the immediate vicinity, to the outlet side of the ejector. The fluid discharged from the ejector via the outlet side thus flows through the compressor, with the fluid flowing through the compressor being able to be guided in the direction of flow via the first and the second heat transfer element to the suction side of the ejector and being introduced into the ejector.

A collector through which the fluid can flow can be arranged between the ejector, in particular the outlet side. The fluid discharged from the ejector via the outlet side thus first flows through the collector and then through the compressor, with the fluid flowing through the collector and the compressor being able to be guided in the direction of flow via the first and the second heat transfer element to the suction side of the ejector and being introduced into the ejector is. In a further embodiment, it is provided that the fluid flowing through the refrigeration circuit in the direction of flow can be guided from the outlet side of the ejector, in particular via the compressor, bypassing the first heat transfer element and/or the second heat transfer element to the drive side of the ejector and can be introduced into the ejector is. In other words, a second fluid stream of the fluid running in the direction of flow from the outlet side of the ejector to the driving side of the ejector runs, in particular via the compressor, bypassing the first heat transfer element and/or the second heat transfer element to the driving side of the ejector. Thus, the first and/or the second heat transfer element is not arranged in the second fluid flow in relation to the second fluid flow, as a result of which the second fluid flow does not run over the first and/or the second heat transfer element. In other words, the ejector, the first and the second heat transfer element are arranged in the refrigeration circuit in such a way that the fluid does not flow in the direction of flow from the outlet side of the ejector via the first and/or the second heat transfer element to the drive side of the ejector.

In a further embodiment, it is provided that the fluid flowing through the refrigeration circuit in the direction of flow can be guided from the outlet side of the ejector via the third heat transfer element, bypassing the first and/or the second heat transfer element, to the drive side of the ejector and via the drive side into the ejector can be initiated. This can be understood in particular as meaning that the third heat transfer element is fluidically connected to the drive side of the ejector in such a way that the fluid flowing through the refrigeration circuit in the direction of flow flows from the outlet side, in particular via the compressor, via the third heat transfer element, bypassing the first heat transfer element and/or of the second heat transfer element can be guided to the driving side of the ejector. In other words, the third heat transfer element is arranged in relation to the second fluid flow of the fluid running in the direction of flow from the outlet side of the ejector, in particular via the compressor, to the drive side of the ejector, as a result of which the second fluid flow runs via the third heat transfer element. In this case, the second fluid stream does not flow through the first heat transfer element and/or the second heat transfer element. Thus, the second fluid flow does not run over the first heat transfer element and/or not over the second heat transfer element. In particular, the fact that the refrigeration cycle Ejector has or due to the arrangement of the heat transfer elements, in particular the third heat transfer element in the refrigeration circuit, the pressure of the fluid supplied to the drive side can be different, in particular greater, than the pressure of the fluid supplied to the suction side. Thus, a respective pressure of the fluid in the third heat transfer element can be different from a respective pressure of the fluid in the first or the second heat transfer element.

It is preferably provided that the fluid flowing through the refrigeration circuit in the direction of flow can be guided from the outlet side of the ejector via the third heat transfer element, bypassing the first and/or the second heat transfer element, to the driving side of the ejector and can be introduced into the ejector via the driving side, while the fluid flowing through the refrigeration circuit in the direction of flow can be guided from the outlet side of the ejector, in particular bypassing the ejector, via the first and/or the second heat transfer element to the suction side of the ejector. This means that the second fluid flow runs over the third heat transfer element, while the first fluid flow runs over the first and the second heat transfer element. In this case, in particular in the first operating mode, the pressure of the fluid on the drive side downstream of the third heat transfer element can be higher than the pressure of the fluid on the suction side.

As a result, the refrigeration circuit can be operated particularly advantageously, in particular particularly efficiently. It is particularly efficient if the driving side of the ejector and thus the third heat transfer element with, in particular a particularly high, first mass flow of the fluid and the suction side or the first and/or the second heat transfer element with a second mass flow of the fluid that is lower than the first mass flow flows through.

The third heat transfer element is preferably arranged on the drive side, in particular directly, in relation to the ejector. This can in particular be understood to mean that the third heat transfer element is arranged close, in particular in the immediate vicinity, to the drive side of the ejector. For example, the fluid flowing through the refrigeration circuit flows directly from the third heat transfer element to the drive side. Preferably, the third heat transfer element is located closer to the drive side than the outlet side. This can be understood in particular as meaning that a first fluid path, which the fluid travels in the direction of flow when flowing through the refrigeration circuit, starting from the outlet side to the third heat transfer element, is greater than a second fluid path, which the fluid travels in the direction of flow when flowing through the refrigeration circuit starting from the third heat transfer element to the driving side of the ejector.

For example, the third heat transfer element is provided, in particular in the first operating mode, to cool an electrical energy store of the motor vehicle or a cooling circuit for the energy store, referred to in particular as a battery cooling circuit. The energy store is preferably a battery or an accumulator of the motor vehicle. The energy store can be designed as a high-voltage component of the motor vehicle. The third heat transfer element can in particular be referred to as a chiller or be designed as a chiller. The battery cooling circuit is preferably designed separately from the air conditioning cooling circuit.

In order to be able to achieve particularly high electrical power for the electrical, in particular purely electrical, driving of the motor vehicle, the energy store can have an electrical voltage, in particular an electrical operating or nominal voltage, which is preferably greater than 50 volts, in particular more than 60 volts, and preferably is several hundred volts. Accordingly, the energy store is preferably designed as a high-voltage component.

For example, in its fully manufactured state, the motor vehicle includes the energy store and the battery cooling circuit. The fourth fluid can flow through the battery cooling circuit. Heat can be dissipated from the battery cooling circuit or the fourth fluid via the third heat transfer element, in particular in the first operating mode, and released to the fluid or the cooling circuit. As a result, the battery cooling circuit can be cooled by the refrigeration circuit via the third heat transfer element. The fluid flowing through the battery cooling circuit and cooled by the fourth heat transfer element can cool the energy store, ie heat from the energy store can be removed from the energy store and introduced into the fourth fluid. The heat introduced into the fourth fluid can have the third Heat transfer element are dissipated to the fluid or the refrigeration circuit. In this way, the battery cooling circuit or the electrical energy store, in particular in the first operating mode, can be cooled by the cooling circuit via the third heat transfer element.

As a result, the refrigeration circuit can be operated particularly advantageously in an operating state referred to in particular as rapid charging and in an operating state referred to in particular as heat pump operation. Fast charging preferably includes maintenance air conditioning of the vehicle interior. Rapid charging can thus be referred to as rapid charging with maintenance air conditioning. Maintaining cooling can in particular be understood to mean that the vehicle interior is cooled by means of the refrigeration circuit, in particular by means of the first heat transfer element. The rapid charging is preferably carried out while the refrigeration circuit is in the first operating state.

Rapid charging can in particular refer to a cooling load case of the energy store, with the energy store having a particularly high cooling requirement in the cooling load case. It can be provided here that a cooling requirement for the cabin during rapid charging, in particular in relation to the cooling requirement of the battery, is at the same time particularly low. A temperature of the fluid can be particularly low or the suction pressure or an evaporation pressure of the fluid can be particularly low. A particularly high refrigerating capacity for cooling the fourth fluid can be achieved, in particular in a particularly efficient manner, by means of the third heat transfer element or its arrangement in the refrigeration circuit. Alternatively or additionally, the fluid introduced into the ejector via the heat transfer elements can have a particularly high pressure during or after being discharged from the ejector via the outlet side. As a result, a power consumption of the compressor can be kept particularly low in order to bring about a predefined pressure of the fluid by means of the compressor downstream of the compressor. For example, a speed of the compressor can be kept particularly low while the drive power of the compressor remains the same or decreases. In particular, this can be referred to as a speed reduction. As a result, the refrigeration circuit can be operated particularly efficiently. The motor vehicle can thus be operated particularly efficiently. Preferably, in particular in the second operating mode, the third heat transfer element, in particular in addition to cooling the battery cooling circuit, is provided to absorb or dissipate heat, in particular referred to as waste heat, from a component of the motor vehicle that is in particular configured separately from the cooling circuit. The component of the motor vehicle is preferably designed separately from the vehicle interior and the electrical energy store.

The component can be, for example, an in particular electric drive train or a drive device of the motor vehicle and/or power electronics of the motor vehicle. The drive device can be an internal combustion engine and/or an electric machine of the motor vehicle, it being possible for the motor vehicle to be driven by means of the internal combustion engine or the electric machine.

For example, in its fully manufactured state, the motor vehicle has the component or the drive device and a cooling circuit, which is in particular configured separately from the cooling circuit and through which a coolant can flow. The cooling circuit is preferably designed separately from the air conditioning circuit and/or the battery cooling circuit. The cooling circuit can be provided to cool the component or the drive device.

The battery cooling circuit and the cooling circuit can be coupled to one another, so that both battery waste heat and drive train waste heat, in particular in the second operating mode, can be supplied to the cooling circuit via the third heat transfer element, in particular by clever connection. This means that the powertrain waste heat and the battery waste heat can be usable at the third heat transfer element in the second operating mode.

The waste heat from the component or the drive device can be removed from the component or the drive device by means of the coolant flowing through the cooling circuit and, in particular in the second operating mode, can be fed to the refrigeration circuit or the fluid via the third heat transfer element. The waste heat can thus be transferred into the refrigeration circuit via the third heat transfer element, as a result of which the waste heat can be absorbed by the fluid. For example this is third heat transfer element can be flowed through or around by the coolant.

In other words, the third heat transfer element can be used, in particular by clever connection in the cooling circuit, preferably in the second operating mode or heat pump mode, to transfer the waste heat from the drive train or from the drive device to the cooling circuit via the third heat transfer element.

In a further embodiment, it is provided that the third heat transfer element is arranged downstream of the ejector or the outlet side of the ejector and upstream of the first and second heat transfer element in relation to the direction of flow of the fluid flowing from the outlet side to the first and second heat transfer element. In other words, the third heat transfer element is fluidically connected, in particular directly, to the outlet side of the ejector in such a way that the fluid flowing through the refrigeration circuit in the direction of flow can be guided from the outlet side of the ejector to the third heat transfer element, with the fluid flowing through the third heat transfer element via the first and the second heat transfer element can be guided to the suction side of the ejector and can be introduced into the ejector. In other words, the third heat transfer element is arranged in the fluid flow in relation to the fluid flow, as a result of which the fluid flow runs over the third heat transfer element. As a result, the efficiency and the performance of the refrigeration circuit can be particularly increased when the third heat transfer element has a particularly high cooling requirement. In addition, the efficiency and the performance in the heat pump operation can be particularly increased. It is particularly advantageous that the effectiveness of the ejector is independent of waste heat supplied to the refrigeration circuit via the third heat transfer element and the first heat transfer element and/or the second heat transfer element.

The effectiveness of the ejector can in particular be understood to mean that corresponding pressures of the fluid present on the suction side and the drive side are in a respective ratio to one another in such a way that the suction of the fluid is the suction side can be realized by means of the ejector. The refrigeration circuit can thus be operated particularly flexibly.

As a result, the efficiency and the performance of the refrigeration circuit can be particularly increased when the cooling requirements of the third heat transfer element are particularly high. As a result, efficiency and performance can also be particularly increased in heat pump operation. Preferably, the waste heat of the component or the drive device supplied to the refrigeration circuit via the third heat transfer element is greater than the heat supplied to the refrigeration circuit by the second heat transfer element and referred to in particular as ambient heat.

The third heat transfer element is preferably arranged on the outlet side in relation to the ejector. This can in particular be understood to mean that the third heat transfer element is arranged close, in particular in the immediate vicinity, to the outlet side of the ejector. For example, the fluid flowing through the refrigeration circuit flows directly from the outlet side to the third heat transfer element.

Preferably, the third heat transfer element is located closer to the outlet side than to the drive side. This can be understood in particular as meaning that the first fluid path, which the fluid travels in the direction of flow when flowing through the refrigeration circuit, starting from the outlet side to the third heat transfer element, is less than the second fluid path, which the fluid travels in the direction of flow when flowing through the refrigeration circuit starting from the third heat transfer element to the driving side of the ejector.

Preferably, at least one fourth heat transfer element through which the fluid can flow and which is configured separately from the heat transfer elements, in particular at a distance from the heat transfer elements, is provided, which is configured as a condenser, as a result of which heat from the refrigeration circuit can be dissipated to a fifth fluid via the fourth heat transfer element. In other words, via the fourth heat transfer element, heat can be removed from the fluid flowing through the fourth heat transfer element and fed to the fifth fluid. In other words, the fifth fluid is via the fourth heat transfer element the fluid or the refrigeration circuit can be heated or the fluid or the refrigeration circuit can be cooled by the fifth fluid via the fourth heat transfer element. As a result, the fifth fluid can be heated particularly advantageously, in particular particularly efficiently, by the refrigeration cycle.

Preferably the fifth fluid is air. The fifth fluid can preferably be supplied to the interior of the motor vehicle for heating the interior. The fifth fluid can thus in particular be referred to as heating air. The heat given off via the fourth heat transfer element to the fifth fluid from the refrigeration cycle can thus be supplied to the interior space by introducing the fifth fluid into the interior space.

For example, in the heat pump operation of the refrigeration circuit, in particular in the first and/or second operating mode, heat can be supplied to the fluid via the first heat transfer element and/or the second heat transfer element and/or the third heat transfer element, with the heat supplied being transferred via the fourth heat transfer element to the fifth fluid can be discharged, in particular for heating the vehicle interior. Thus, in particular because the fluid circuit includes the fourth heat transfer element, the functionality with regard to the heat pump can be made possible by means of the refrigeration circuit. When the interior is heated, the interior can be heated particularly efficiently by means of the refrigeration circuit or the fourth heat transfer element or the fifth fluid. For example, in the fully manufactured state, the motor vehicle has an electrical heating system which is designed separately from the refrigeration circuit and by means of which the interior can be heated. The efficiency of heating the interior using the refrigeration circuit, in particular the fourth heat transfer element or the fifth fluid, is higher than the efficiency of heating the interior using the electrical heating system. As a result, the motor vehicle can be operated particularly efficiently. In heat pump operation, the drive power of the compressor is preferably supplied to the fluid by means of the compressor.

In particular because the refrigeration circuit has the ejector, the heat can be absorbed via the third heat transfer element at a higher pressure of the fluid than when the heat is absorbed from the fluid via the second heat transfer element. As a result, the refrigeration circuit can be operated particularly efficiently in the heat pump mode, in particular with a particularly high heat input into the refrigeration circuit via the third heat transfer element. An evaporation pressure of the fluid flowing through the third heat transfer element is preferably higher than an evaporation pressure of the fluid flowing through the second heat transfer element. As a result, a respective mass flow of the fluid flowing through the third heat transfer element can be higher than a respective mass flow flowing through the second heat transfer element, as a result of which a higher heat flow can be absorbed by the fourth fluid via the third heat transfer element than by the second fluid via the second heat transfer element . As a result, the waste heat absorbed by the component or the drive device in the refrigeration cycle can be particularly high.

For example, the fourth heat transfer element has a seventh flow region through which the fluid can flow and an eighth flow region through which or around which the fifth fluid can flow. The seventh flow area and the eighth flow area are preferably not fluidically connected to one another. Thus, the fluid flowing through the seventh flow area cannot get into the eighth flow area or the fifth fluid flowing around or through the eighth flow area cannot get into the seventh flow area. The second flow area and/or the fourth flow area and the eighth flow area can be fluidly connected or can be connected to one another or not fluidly connected. The fourth heat transfer element can in particular be referred to as a heating condenser.

The fact that the fourth heat transfer element is designed as a condenser can be understood in particular as meaning that at least part of the fluid flowing through the fourth heat transfer element can be condensed as a result of the heat dissipated from the fluid to the fifth fluid via the fourth heat transfer element. In other words, at least part of the fluid entering the fourth heat transfer element is gaseous, with at least part of the gaseous fluid flowing through the fourth heat transfer element being liquefiable by means of the fourth heat transfer element or as a result of the heat given off by the fluid to the fifth fluid. The liquid portion of the fluid can thus be greater when the fluid exits the fourth heat transfer element than when the fluid enters the fourth heat transfer element. In other words, the gas content at the exit of the fluid from the fourth Heat transfer element may be lower than when the fluid enters the fourth heat transfer element. Upon entry into the fourth heat transfer element, the fluid can only be present in the gas phase and can therefore be present entirely as a gas. When exiting the fourth heat transfer element, the fluid can only be in the liquid phase or can be completely liquid.

The fourth heat transfer element is preferably arranged downstream of the outlet side, in particular downstream of the compressor, in relation to the fluid flowing from the outlet side of the ejector to the first and the second heat transfer element. The fourth heat transfer element is preferably arranged upstream of the first and the second heat transfer element in relation to the fluid flow in the fluid flow. The fourth heat transfer element can be arranged downstream or upstream of the third heat transfer element in relation to the second fluid flow in the second fluid flow.

In a further embodiment it is provided that the first heat transfer element, in particular in the first operating mode, is arranged downstream of the second heat transfer element in relation to the fluid flowing in the direction of flow from the second heat transfer element to the ejector, in particular the suction side. In other words, the first heat transfer element, in particular in the first operating mode, is arranged downstream of the second heat transfer element in relation to the fluid flow in the fluid flow, as a result of which the fluid flow runs from the outlet side to the first heat transfer element via the second heat transfer element. To put it another way, the first and the second heat transfer element are fluidically connected or arranged in series, with the second heat transfer element being arranged in the fluid flow upstream of the first heat transfer element. As a result, the fluid can flow through the refrigeration circuit in a particularly advantageous manner.

In a preferred embodiment, it is provided that the second heat transfer element in the first operating mode, relative to the fluid flowing in the direction of flow from the second heat transfer element to the ejector, in particular the suction side and the drive side, upstream of the first heat transfer element and upstream of the third heat transfer element is arranged. In other words, in the first operating mode, the second heat transfer element is arranged in relation to the respective fluid flow in the respective fluid flow upstream of the first heat transfer element and the third heat transfer element, as a result of which the fluid flow runs from the outlet side to the first heat transfer element via the second heat transfer element and the second Fluid flow runs from the outlet side to the third heat transfer element via the second heat transfer element. In other words, in the first operating mode, the first and the second heat transfer element are fluidically connected or arranged in series and the second and the third heat transfer element are fluidically connected or arranged in series, with the second heat transfer element being arranged in the fluid flow upstream of the first heat transfer element and the second Heat transfer element is arranged in the second fluid flow upstream of the third heat transfer element. As a result, the fluid can flow through the refrigeration circuit in a particularly advantageous manner.

In a further embodiment, provision is made for the first and/or the second heat transfer element to be fluidically connected directly to the suction side of the ejector in the second operating mode. For example, in the second operating mode, the fluid flowing through the refrigeration circuit in the direction of flow can be guided from the outlet side via the first and/or the second heat transfer element to the suction side of the ejector, with the fluid being guided from the suction side via the first and/or the second heat transfer element to the driving side of the ejector or to the third heat transfer element is omitted.

In a further embodiment, it is provided that the second heat transfer element is arranged in a first longitudinal area of the refrigeration circuit and the first heat transfer element is arranged in a second longitudinal area of the refrigeration circuit. In other words, the refrigeration circuit has the first and second length ranges, with the second heat transfer element being in the first length range and the first heat transfer element being in the second length range. The fluid can flow through the longitudinal regions. The first length range and the second length range are preferably different from one another. In a further embodiment, it is provided that the length ranges, based on the fluid flowing through the refrigeration circuit in the direction of flow, can be switched in series with one another in terms of flow mechanics or in parallel with one another in terms of flow mechanics. This can in particular be understood to mean the following. The length regions can be traversed in parallel and serially by the fluid in the direction of flow. The refrigeration circuit has at least one switching device, by means of which the longitudinal areas can be fluidically switched to one another in such a way that the longitudinal areas can be flowed through fluidically in series or fluidically in parallel or fluidically in series and parallel. In other words, the switching device can be switched between at least two states, wherein in a first of the states the longitudinal areas can be flowed through serially in terms of fluid mechanics and in a second of the states the longitudinal areas can be flowed through in parallel in terms of fluid mechanics. Preferably, the switching device also has a third state, in which case the longitudinal regions can be flowed through in parallel and in series in terms of fluid mechanics. Since the longitudinal areas can be connected in parallel and in series with one another in terms of flow mechanics, the fluid can flow through the refrigeration circuit in a particularly flexible manner, as a result of which, for example, the refrigeration capacity and/or the efficiency of the refrigeration circuit can be adjusted particularly flexibly.

Provision is preferably made for the second length region to be arranged downstream of the first length region in the first operating mode, with respect to the fluid flowing in the direction of flow from the first length region to the ejector.

Provision is preferably made for the length ranges in the first operating mode to be connected or switchable in series with one another in terms of flow mechanics in relation to the fluid flowing through the refrigeration circuit in the direction of flow. In other words, the length ranges can be traversed serially in the first operating mode. Thus, in the first operating mode, the first and the second heat transfer element have a serial flow through them or are connected in series with one another. This means that in the first operating mode, the fluid flows through the first and the second heat transfer element in series from the outlet side to the suction side of the ejector. As a result, the refrigeration circuit can be operated particularly advantageously, in particular particularly efficiently, in the first operating mode. Provision is preferably made for the longitudinal regions in the second operating mode to be connected or to be connected parallel to one another in terms of flow mechanics in relation to the fluid flowing through the refrigeration circuit in the direction of flow. In other words, the longitudinal regions can be flown through in parallel in the second operating mode. Thus, in the second operating mode, the fluid flows through the first and the second heat transfer element in parallel or is connected in parallel to one another. This means that in the second operating mode, the fluid flows through the first and the second heat transfer element in parallel from the outlet side to the suction side of the ejector. As a result, the refrigeration circuit can be operated particularly advantageously, in particular particularly efficiently, in the second operating mode.

Alternatively, it can be provided that the length ranges in the second operating mode related to the fluid flowing through the refrigeration circuit in the direction of flow are connected or can be connected in series with one another in terms of flow mechanics. In other words, the length ranges can be traversed serially in the second operating mode. Thus, in the second operating mode, the fluid flows through the first and the second heat transfer element in series or is connected in series with one another. This means that in the second operating mode, the fluid flows through the first and the second heat transfer element in series from the outlet side to the suction side of the ejector. This can be implemented with particularly little effort, in particular structurally. As a result, the costs of the refrigeration circuit can be kept particularly low.

Preferably, in the first operating mode and/or in the second operating mode, the first and the second heat transfer element are fluidically connected to the suction side in such a way that the fluid flowing through the refrigeration circuit in the flow direction moves from the outlet side via the first and the second heat transfer element to the suction side of the Ejector can be guided or is guided and can be introduced or is introduced via the suction side into the ejector. This means that the first and/or the second heat transfer element is/are preferably, in particular directly, arranged on the suction side in the first and/or the second operating mode. Alternatively, the flow through the first heat transfer element can be omitted in the second operating mode. This means that the second heat transfer element is preferably, in particular directly, arranged on the suction side in the second operating mode.

In the second operating mode, the first and the second heat transfer element are preferably each arranged, in particular directly, on the suction side. This can be realized in that the first and the second heat transfer element or the longitudinal areas are flowed through in parallel in terms of fluid mechanics in the second operating mode.

Alternatively or additionally, it is preferably provided in the second operating mode that the fluid flowing through the refrigeration circuit in the direction of flow can be guided or is guided from the outlet side of the ejector via the second heat transfer element, bypassing the first heat transfer element, to the suction side of the ejector and via the suction side into the ejector is or is initiated. Thus, in the second operating mode, the second heat transfer element is preferably, in particular directly, arranged on the suction side.

In a further embodiment, a branching point through which the fluid can flow is provided, via which the fluid flowing through the branching point in the direction of flow can be divided into the first and/or the second length region. In other words, the branching point is arranged in relation to the fluid flow in the fluid flow upstream of the first and second heat transfer element or upstream of the longitudinal regions, as a result of which the fluid flow runs via the branching point, with at least part of the fluid flowing through the branching point being able to be introduced into the first longitudinal region and the other part of the fluid flowing through the branch point can be introduced into the second length region. For example, the parallel flow through the longitudinal regions can be realized in particular by means of the second branching point. This means that the refrigerant circuit can be flowed through particularly flexibly. For example, the switching device can include the branching point.

The fact that the fluid flowing through the branching point can be divided between the first and the second length range can in particular be understood to mean any quantity ratio in which the fluid in the first or the second length range can be initiated or is initiated. For example, a complete mass flow of the fluid flowing through the branching point can be introduced via the branching point into the first length region, whereas the introduction of the fluid via the branching point into the second length region does not take place. For example, the complete mass flow of the fluid flowing through the branch point can be introduced via the branch point into the second length region, whereas the introduction of the fluid via the branch point into the first length region is omitted. For example, a portion of the mass flow introduced via the branching point into the first length range may be greater, smaller or the same as another portion or the remaining portion of the mass flow introduced via the branching point into the second length range.

In a further embodiment, at least one line element through which the fluid can flow is provided, which is fluidically connected to the first length region at a first connection point located downstream of the second heat transfer element, based on the fluid flowing through the first length region in the direction of flow, and at one, based on the fluid flowing through the second length region in the direction of flow is fluidically connected to the second connection point arranged upstream of the first heat transfer element, whereby at least part of the fluid flowing through the first length region can be guided via the line element from the first connection point to the second connection point and at the second connection point can be introduced into the second longitudinal region. In other words, the connection points and the line element are arranged in relation to the fluid flow in the fluid flow, as a result of which the fluid flow runs through the first length region via the second heat transfer element and the first connection point and can then be discharged via the line element from the first length region and at the second Connection point can be introduced into the second length region, whereby the fluid flow runs over the line element and the second connection point and the first heat transfer element. In other words, the first length area and the second length area are fluidically connected to one another via the line element and the connection points, in particular directly, whereby the fluid flowing through the first length area can be guided via the connection points and the line element into the second length area. This allows, for example, the serial switching of the length ranges can be realized. For example, the switching device includes the connection points or the line element.

In a further embodiment, at least one fifth heat transfer element through which the fluid can flow and which is configured separately from the heat transfer elements, in particular at a distance from the heat transfer elements, is provided, which is configured as an evaporator, as a result of which heat from a sixth fluid can be supplied to the refrigeration circuit via the fifth heat transfer element. In other words, heat can be dissipated from the sixth fluid via the fifth heat transfer element, wherein the dissipated heat can be supplied to the fluid flowing through the fifth heat transfer element via the fifth heat transfer element. In other words, the fluid can be heated by the sixth fluid via the fifth heat transfer element or the sixth fluid can be cooled by the fluid via the fifth heat transfer element.

The fact that the fifth heat transfer element is designed as an evaporator can be understood in particular as meaning that at least part of the fluid flowing through the fifth heat transfer element can be evaporated as a result of the heat supplied by the fifth fluid via the fifth heat transfer element. In other words, at least part of the fluid entering the fifth heat transfer element is liquid, with at least part of the liquid part of the fluid or at least part of the fluid flowing through the fifth heat transfer element being supplied by the fifth heat transfer element as a result of the fluid supplied to the fluid by the sixth Heat is evaporable. Thus, the gas content of the fluid when it exits the fifth heat transfer element can be higher than when it enters the fifth heat transfer element. For example, the fluid entering the fifth heat transfer element can be completely liquid or can be completely in a liquid phase. For example, the fluid flowing through the fifth heat transfer element can be completely evaporated, as a result of which the fluid can be present completely in the gas phase or as a gas when it exits the fifth heat transfer element.

Below the first heat transfer element and/or the second heat transfer element and/or the third heat transfer element and/or the fourth heat transfer element and/or the fifth heat transfer element can in particular be understood as a respective heat exchanger.

The fifth heat transfer element is preferably provided to cool the vehicle interior. The sixth fluid, in particular referred to as cooling air, is preferably air. The fifth heat transfer element is preferably provided to cool a rear area of the vehicle interior, the first heat transfer element being provided to cool a front area of the vehicle interior that is different from the rear area. The front area can be understood in particular as a front area of the vehicle interior, based on a driving direction of the motor vehicle. The rear area is therefore arranged behind the front area in relation to the direction of travel of the motor vehicle. The sixth fluid can preferably be cooled via the fifth heat transfer element and introduced into the rear area of the vehicle interior.

A second aspect of the invention relates to a method for operating a refrigeration circuit through which a fluid can flow for a motor vehicle. Advantages and advantageous configurations of the first aspect of the invention are to be regarded as advantages and advantageous configurations of the second aspect of the invention and vice versa.

The method provides for a fluid to flow through an ejector having an intake side, a drive side and an outlet side, with the fluid being discharged from the ejector via the outlet side and the fluid discharged from the ejector via the outlet side and entering the refrigeration circuit in one Fluid flowing through the direction of flow, in particular bypassing the ejector, is introduced via the suction side and the drive side into the ejector. In other words, the fluid circulates through the refrigeration circuit, with the fluid flowing through the ejector being discharged from the ejector via the outlet side of the ejector, and the fluid discharged from the ejector being returned to the ejector via the suction side and the driving side of the ejector.

The fluid flows through at least one first heat transfer element designed as an evaporator, with heat being supplied to the refrigeration cycle by a second fluid via the first heat transfer element. In other words, takes place in the heat transfer element Heat transfer between the fluid and the second fluid takes place, with heat being removed during the heat transfer from the second fluid flowing through or around the first heat transfer element and being supplied to the first fluid flowing through the first heat transfer element.

The fluid flows through a second heat transfer element that is formed separately from the first heat transfer element, in particular at a distance from the first heat transfer element, wherein the second heat transfer element can be operated as a condenser, whereby heat can be dissipated from the refrigeration circuit to a third fluid via the second heat transfer element. In other words, heat transfer between the fluid and the third fluid can take place in the second heat transfer element, with heat being removed during the heat transfer from the fluid flowing through the second heat transfer element and being supplied to the third fluid flowing around or through the second heat transfer element.

The fluid flows through a third heat transfer element that is designed separately from the heat transfer elements, the third heat transfer element being designed as an evaporator, as a result of which heat from a fourth fluid is supplied to the refrigeration circuit via the third heat transfer element. In other words, heat transfer takes place in the third heat transfer element between the fluid and the fourth fluid, with heat being removed during the heat transfer from the fourth fluid flowing through or around the third heat transfer element and being supplied to the fluid flowing through the third heat transfer element.

In order to be able to operate the refrigeration circuit, in particular by means of the ejector, particularly advantageously, in particular particularly efficiently and/or with a particularly high refrigeration capacity, it is provided according to the invention that the fluid flowing through the refrigeration circuit in the direction of flow from the outlet side of the ejector via the first and/or or the second heat transfer element, is led to the suction side of the ejector and introduced into the ejector via the suction side. In other words, the fluid discharged from the ejector via the outlet side of the ejector first flows through the first and/or the second heat transfer element before it is fed back to the ejector via the suction side of the ejector. In addition, the method provides for the second heat transfer element to be operated as the condenser in a first operating mode of the refrigeration circuit, as a result of which heat is dissipated from the refrigeration circuit to the third fluid via the second heat transfer element, and in a second operating mode that differs from the first Operating mode of the refrigeration circuit is operated as an evaporator, whereby the refrigeration circuit via the second heat transfer element heat is supplied from the third fluid. In other words, in the first operating mode, heat is transferred from the fluid to the third fluid via the second heat transfer element, and in the second operating mode, heat is transferred from the third fluid to the fluid via the second heat transfer element.

In particular when the third heat transfer element is arranged on the driving side or the outlet side in relation to the ejector, the refrigeration circuit can be operated particularly advantageously. In particular, the efficiency of the refrigeration circuit can be particularly increased.

In particular when the third heat transfer element is arranged on the suction side in relation to the ejector, the refrigeration circuit can be operated particularly advantageously in the second operating mode. For the operation of the refrigeration circuit in the first operating mode, the arrangement of the third heat transfer element on the drive side, that is to say the arrangement of the third heat transfer element on the drive side, can be more advantageous. Thus, depending on the focus, the third heat transfer element can be arranged on the suction side or on the drive side in relation to the ejector in a particular configuration of the refrigeration circuit. That means, depending on the focus, one or the other configuration can be chosen.

Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments and from the drawings. The features and combinations of features mentioned above in the description and the features and combinations of features mentioned below in the description of the figures and/or shown alone in the figures can be used not only in the combination specified in each case, but also in other combinations or on their own, without going beyond the scope of the leave invention. show:

1 shows a schematic partial sectional view of a refrigeration circuit according to the invention, which can be operated by means of a method according to the invention; and

2 shows a schematic partial sectional view of a refrigeration circuit according to the invention according to a further embodiment.

Elements that are the same or have the same function are provided with the same reference symbols in the figures.

1 shows a refrigeration circuit 10 for a motor vehicle in a schematic partial sectional view. A fluid 12 can flow through the refrigeration circuit 10 . The refrigeration circuit 10 can be operated with a method. The fluid 12 thus flows through the refrigeration circuit 10 in the method for operating the refrigeration circuit 10 . The fluid 12 is preferably a refrigerant.

The refrigeration circuit 10 includes an ejector 14 through which the fluid 12 can flow, which has a suction side 16 , a drive side 18 and an outlet side 20 . The ejector 14 or the suction side 16 has a first flow opening 22 through which the fluid can flow. The ejector 14 or the drive side 18 has a second flow opening 24 spaced apart from the first flow opening 22 and through which the fluid 12 can flow. The ejector 14 or the outlet side 20 has a third flow opening 26 spaced apart from the flow openings 22 , 24 and through which the fluid 12 can flow. The ejector 14 has an ejector interior 28 through which the fluid 12 can flow. The ejector interior 28 is at least partially, in particular completely, delimited by the walls of the ejector 14 . The fluid 12 can be discharged from the ejector 14 or the ejector interior 28 via the outlet side 20 or the third flow opening 26 . The fluid 12 can be introduced into the ejector 14 or the ejector interior 28 via the suction side 16 or the first flow opening 22 . The fluid 12 can be introduced into the ejector 14 or the ejector interior 28 via the driving side 18 or the second through-flow opening 24 . The refrigeration circuit 10 is of the fluid 12 in one Flow direction 30 can be flowed through. The fluid 12 discharged from the ejector 14 or the ejector interior 28 via the outlet side 20, in particular the third flow opening 26, and flowing through the refrigeration circuit 10 in the direction of flow 30, in particular bypassing the ejector 14, in particular the ejector interior 28, via the suction side 16 , In particular the first through-flow opening 22, and the driving side 18, in particular the second through-flow opening 24, in the ejector 14, in particular the ejector interior 28, can be introduced. In other words, the fluid 12 flows through the ejector 14, in particular the ejector interior 28, with the fluid 12 being discharged via the outlet side 20, in particular the third through-flow opening 26, from the ejector 14, in particular the ejector interior 28, and that Fluid 12 discharged from the ejector 14 via the outlet side 20 and flowing through the refrigeration circuit 10 in the flow direction 30 is, in particular bypassing the ejector 14 or the ejector interior 28, via the suction side 16, in particular the first flow opening 22, and the drive side 18, in particular the second flow opening 24, in the ejector 14, in particular the ejector interior 28, introduced.

The refrigeration circuit 10 has at least one first heat transfer element 34 , through which the fluid 12 can flow and designed as an evaporator 32 , via which heat 36 from a second fluid 38 can be supplied to the refrigeration circuit 10 . The fluid 12 thus flows through the first heat transfer element 34 , heat 36 being supplied by the second fluid 38 to the refrigeration circuit 10 or to the fluid 12 flowing through the first heat transfer element 34 via the first heat transfer element 34 . Thus, the second fluid 38 is cooled by the fluid 12 via the first heat transfer element 34 . The second fluid 38 is preferably air, referred to in particular as cooling air. The cooled cooling air is preferably supplied to an interior of the motor vehicle, referred to in particular as the vehicle interior, for cooling the interior.

The refrigeration circuit 10 has a second heat transfer element 40 through which the fluid 12 can flow and is formed separately from the first heat transfer element 34, in particular at a distance from the first heat transfer element 34, which can be operated as a condenser 42, whereby heat 44 from the refrigeration circuit 10 to a third fluid 46 can be discharged. Thus, the refrigeration circuit 10 or the second heat transfer element 40 flowing through fluid 12 via the second Heat transfer element 40 are cooled by the third fluid 46. The third fluid 46 is preferably air, referred to in particular as ambient air. The ambient air can be introduced into the motor vehicle from an area surrounding the motor vehicle and fed to the second heat transfer element 40 for example via a feed device, as a result of which the third fluid 46 flows through or around the second heat transfer element 40 . Preferably, the third fluid 46 is not routed through the vehicle interior.

The refrigeration circuit 10 has a first line section 48 through which the fluid 12 can flow. The first line section is fluidically connected to the outlet side 20 , in particular to the third flow opening 26 , and is connected, in particular directly, to an input 50 of the second heat transfer element 40 . Thus, the fluid 12 flowing through the refrigeration circuit 10 can be supplied to the second heat transfer element 40 via the first line section 48 and introduced into the second heat transfer element 40 .

The refrigeration circuit has a partial area 178 through which the fluid can flow. The refrigeration circuit 10 has a second line section 180 through which the fluid 12 can flow. The second line section 180 is fluidically connected, in particular directly, to an outlet 54 of the second heat transfer element 40 and, in particular directly, fluidically to a first inlet 182 of the partial area 178 . In other words, the second line section 180 is connected at one end, in particular directly, to the outlet 54 of the second heat transfer element 40 and at the other end, in particular directly, fluidly connected to the first inlet 182 of the partial area 178 . Thus, the fluid 12 flowing through the second heat transfer element 40 can be removed from the second heat transfer element 40 via the outlet 54 and introduced into the second line section 180, wherein the fluid flowing through the second line section 180 can be supplied to the partial region 178 via the first inlet 182 and can be introduced into the sub-area.

The portion 178 has a first exit 184 spaced apart from the first entrance 182 . The first inlet 182 and the first outlet 184 are fluidically connected to one another or can be fluidly connected to one another. As a result, the fluid 12 introduced into the partial area 178, in particular via the inlet 182, can be discharged from the partial area 178. The refrigeration circuit 10 has a third line section 52 through which the fluid 12 can flow. The third line section 52 is fluidically connected, in particular directly, to the first outlet 184 of the partial region 178 and, in particular directly, fluidically to an inlet 56 of the first heat transfer element 34 . In other words, the third line section 52 is connected at one end, in particular directly, to the first outlet 184 of the partial area 178 and at the other end, in particular directly, fluidly connected to the inlet 56 of the first heat transfer element 34 . Thus, the fluid 12 discharged from the subregion 178 via the first outlet 184 can be introduced into the third line section 52, wherein the fluid flowing through the third line section 52 can be fed via the inlet 56 to the first heat transfer element 34 and can be introduced into the first heat transfer element 34 can be. Thus, the fluid 12 flowing through the second heat transfer element 40 can be supplied to the first heat transfer element 34 via the outlet 54, the second line section 180, the partial area 178, in particular the first inlet 182 and the first outlet 184, and the third line section 52 via the inlet 56 and introduced into the first heat transfer element 34 .

The refrigeration circuit 10 has at least one fourth line section 58 through which the fluid can flow. The fourth line section 58 is fluidically connected at one end, in particular directly, to an outlet 60 of the first heat transfer element 34 and at the other end, in particular directly, to a second inlet 186 of the subregion 178, which is spaced apart from the first inlet 182 and the first outlet 184. The fluid 12 flowing through the first heat transfer element 34 can thus be removed from the first heat transfer element 34 via the outlet 60 and introduced into the fourth line section 58, with the fluid 12 flowing through the fourth line section 58 being introduced into the partial region 178 via the second inlet 186 can.

The portion 178 has a second output 188 spaced apart from the inputs 182 , 186 and the first output 184 . The second outlet 188 is or can be fluidly connected to the first inlet 182 and/or the second inlet 186 . The fluid 12 introduced into the subregion 178, in particular via the first and/or the second inlet 182, 186, can be discharged from the subregion 178 via the second outlet 188. The refrigeration circuit 10 has at least one fifth line section 190 through which the fluid can flow. The fifth line section 190 is fluidly connected at one end, in particular directly, to the second outlet 188 of the partial area 178 and at the other end, in particular directly, to the suction side 16 or the first through-flow opening 22 . The fluid 12 discharged from the partial area 178 via the second outlet 188 can thus be introduced into the fifth line section 190, with the fluid 12 flowing through the fifth line section 190 being fed via the suction side 16, in particular the first through-flow opening 22, into the ejector 14, in particular the ejector interior 28 can be initiated. Thus, the fluid 12 flowing through the first heat transfer element 34 can flow via the outlet 60, the fourth line section 58, the partial area 178, in particular the second inlet 186 and the second outlet 188, and the fifth line section 190 via the suction side 16, in particular the first flow opening 22 , Can be introduced into the ejector 14, in particular the ejector interior 28.

The refrigeration circuit 10 has at least one third heat transfer element 70 through which the fluid 12 can flow and which is formed separately from the heat transfer elements 34, 40, in particular at a distance from the heat transfer elements 34, 40, which is embodied as an evaporator 72, whereby the refrigeration circuit 10 via the third heat transfer element 70 heat 74 of a fourth fluid 76 can be supplied.

The fourth fluid 76 is preferably a coolant or a cooling medium, in particular cooling water.

In its fully manufactured state, the motor vehicle preferably has an energy store and a cooling circuit, which is provided for cooling the energy store. The energy store is preferably a battery, by means of which electrical energy can be made available for, in particular, purely electrical driving of the motor vehicle. The cooling circuit can therefore be referred to as a battery cooling circuit in particular.

The fourth fluid 76 preferably flows through the cooling circuit or the battery cooling circuit, as a result of which the energy store can be cooled by the fourth fluid 76 . Thus, the fourth fluid 76 can be cooled by the fluid 12 or the refrigeration circuit 10 via the third heat transfer element 70, whereby the energy store of the motor vehicle is at least indirectly absorbed by the refrigeration circuit 10 or the fluid 12 can be cooled. The third heat transfer element 70 can in particular be referred to as a chiller.

In the second operating mode 64 , in particular if the connection is skilful, waste heat from a drive train of the motor vehicle can be transferred or absorbed into the cooling circuit and transferred or absorbed into the cooling circuit 10 via the third heat transfer element 70 .

The refrigeration circuit 10 has a sixth line section 78 through which the fluid 12 can flow. A first branch point 80 is arranged in the first line section 48 , in particular upstream of the second heat transfer element 40 in relation to the direction of flow 30 of the fluid 12 flowing through the first line section 48 . The sixth line section 78 is fluidly connected at one end, in particular directly, via the first branch point 80 to the first line section 48 . The sixth line section 78 is fluidically connected at the other end, in particular directly, to a third inlet 192 of the partial region 178 which is at a distance from the inlets 182, 186 and the outlets 184, 188. Thus, at least part of the fluid 12 flowing through the first line section 48 can be removed from the first line section 48 via the first branch point 80 and fed to the third inlet 192 via the sixth line section 78 and introduced into the partial area 178.

The portion 178 has a third output 194 spaced apart from the inputs 182, 186, 192 and the outputs 184, 188. The third outlet 194 is fluidically connected or connectable to the first and/or the second and/or the third inlet 182, 186, 192. Thus, the fluid 12 introduced into the partial area 178, in particular via the first and/or the second and/or the third inlet 182, 186, 192, can be discharged from the partial area 178.

The refrigeration circuit 10 has a seventh line section 196 through which the fluid 12 can flow. The seventh line section 196 is fluidically connected at one end, in particular directly, to the third outlet 194 . The seventh line section 196 is fluidically connected at the other end, in particular directly, to the drive side 18 , in particular to the second flow-through opening 24 . Thus, the fluid discharged from the partial area 178 via the third outlet 194 can be supplied to the driving side 18 of the ejector 14 via the seventh line section 196 and introduced into the ejector 14 . Thus, at least a portion of the fluid 12 flowing through the first line section 48 can be removed from the first line section 48 via the first branch point 80 and via the sixth line section 78, the partial area 178, in particular the third inlet 192 and the third outlet 194, and the seventh Line section 196 of the driving side 18 of the ejector 14 are supplied.

In particular, via the sixth line section 78, the fluid 12 flowing through the refrigeration circuit 10 in the flow direction 30 is conveyed from the outlet side 20, bypassing the first heat transfer element 34 and/or the second heat transfer element 40, in particular bypassing the second line section 180 and/or the third line section 52 , to the driving side 18 of the ejector 14 out.

In the exemplary embodiment shown in Fig. 1, the third heat transfer element 70 is arranged in the sixth line section 78, whereby the fluid 12 flowing through the refrigeration circuit 10 in the direction of flow 30 flows from the outlet side 20 via the third heat transfer element 70, bypassing the first and the second heat transfer element 34 , 40, in particular by bypassing the second and/or third and/or fifth line sections 180, 52, 190, to the driving side 18 of the ejector 14 and via the driving side 18, in particular the second flow opening 24, into the ejector 14, in particular in the ejector interior 28 can be introduced. The third heat transfer element 70 is preferably arranged on the drive side. This means that the third heat transfer element 70 is arranged on or, in particular directly, on the drive side 18 .

In order to be able to operate the refrigeration circuit 10 having the ejector 14 particularly advantageously, in particular particularly efficiently and/or with a particularly high refrigerating capacity, it is provided that the heat transfer elements 34, 40 are fluidically connected in this way to the suction side 16, in particular to the first through-flow opening 22 are that the fluid 12 flowing through the refrigeration circuit 10 in the flow direction 30 can be guided from the outlet side 20, in particular the third through-flow opening 26 of the ejector 14, via the heat transfer elements 34, 40 to the suction side 16, in particular the first through-flow opening 22, of the ejector 14 and via the suction side 16, in particular the first through-flow opening 22, into the ejector 14, in particular the ejector interior 28, can be introduced. Thus, the fluid 12 flowing through the refrigeration circuit 10 in the direction of flow 30 of the Outlet side 20 of the ejector 14 via at least one of the heat transfer elements 34, 40, in particular via both heat transfer elements 34, 40, to the suction side 16 of the ejector 14 out. The second heat transfer element 40 can be operated as the condenser 42 in a first operating mode 62 of the refrigeration circuit 10, and the second heat transfer element 40 can be operated as the evaporator 66 in a second operating mode 64 of the refrigeration circuit 10 that differs from the first operating mode 62, whereby the refrigeration circuit 10 via the second heat transfer element 40 can be supplied with heat 68 from the third fluid 46 . In other words, the second heat transfer element 40 is operated in the first operating mode 62 as the condenser 42, whereby heat 44 is removed via the second heat transfer element 40 from the refrigeration circuit 10 or from the fluid 12 flowing through the second heat transfer element 40 and is supplied to the third fluid 46 . In the second operating mode 64, the second heat transfer element 40 is operated as the evaporator 66, whereby heat from the third fluid 46 is supplied to the refrigeration circuit 10 or to the fluid 12 flowing through the second heat transfer element 40 via the second heat transfer element 68.

In particular because the third heat transfer element 70 is arranged in the seventh line section 196 or on the drive side, the refrigeration circuit 10 can be operated particularly advantageously, in particular particularly efficiently. A pressure of the fluid 12 in the seventh line section 196 or a pressure of the fluid 12 on the driving side can differ from a pressure of the fluid 12 in the fifth line section or to a pressure of the fluid 12 on the suction side. As a result, the first and/or the second heat transfer element 34 , 40 be or be operated at least partially decoupled from the third heat transfer element 70 .

In a further configuration, the second heat transfer element 40 is arranged in a first longitudinal region 158 of the refrigeration circuit 10 through which the fluid 12 can flow, and the first heat transfer element 34 is arranged in a second longitudinal region 160 of the refrigeration circuit 10 through which the fluid 12 can flow. The length ranges 158, 160 are different from each other.

Preferably, the first length range 158 extends based on the

Flow direction 30, starting from the first junction 80 on the first Line section 48 and the second line section 180 up to the first inlet 182 of the partial area 178. The second length range 160 preferably extends, based on the flow direction 30, starting from the first outlet 184 of the partial area 178 via the third line section 52 and the fourth line section 58 to the second entrance 186 of the sub-area 178.

In a further configuration, the first heat transfer element 34 is arranged or connected downstream of the second heat transfer element 40 in relation to the fluid 12 flowing in the flow direction 30 from the second heat transfer element 40 to the ejector 14, in particular in the first operating mode 62. In other words, the line sections 48, 52 are arranged in the fluid flow in relation to a fluid flow of the fluid 12 running in the flow direction 30 from the outlet side 20 to the suction side 16, in particular in the first operating mode 62, whereby the fluid flow via the line sections 48 , 52, the first line section 48 being arranged in the fluid flow upstream of the third line section 52.

In a further embodiment, it is provided that the longitudinal regions 158, 160, based on the fluid flowing through the refrigeration circuit 10 in the direction of flow 30, can be switched either fluidically in series or fluidically parallel to one another. This means that the flow can flow through the heat transfer elements 34, 40 either in series or in parallel in terms of fluid mechanics. As a result, the refrigeration cycle 10 can be operated particularly flexibly.

For example, when the longitudinal regions 158, 160 are connected in series, the first inlet 182 and the first outlet 184 are fluidically connected to one another in such a way that the fluid flowing through the first longitudinal region 158 or the second heat transfer element 40 passes through the partial region 178 or through the partial region 178, in particular can be introduced via the first inlet 182 and the first outlet 184 into the second length region 160 or into the first heat transfer element 34 .

The third inlet 192 is preferably not fluidically connected to the first outlet 184 via the partial area 178 .

For example, the length ranges are switched parallel to one another in terms of flow mechanics

158, 160, the fluid flowing through the power path 48 at the first Branch point 80 divided into a first partial flow and a second partial flow. As a result, the first partial flow flows from the first branch point 80 in the direction of flow 30 via the second heat transfer element 40 to the first inlet 182 of the partial region 178. In addition, the second partial flow flows from the first branch point 80 via the sixth line section 78 to the third inlet 192 of the subregion 178. For example, the first inlet 182 and the second and/or the third outlet 188, 194 are fluidically connected to one another via the subregion 178, with the first inlet 182 not being fluidically connected to the first outlet 184 via the subregion 178. As a result, the first partial flow introduced via the first inlet 182 into the partial area 178 can be introduced via the second outlet 188 into the fifth line section 190 and/or via the third outlet 194 into the seventh line section. In addition, the second partial flow introduced into the partial area 178 via the third inlet 192 can be introduced into the third line section 52 via the first outlet 184 . The first partial flow can thus flow through the first longitudinal region 158 or the second heat transfer element 40, while the first partial flow does not flow through the second longitudinal region 160 or the first heat transfer element 34, with the second partial flow being able to flow through the second longitudinal region 160 or the first heat transfer element 34, while the second partial flow does not flow through the first longitudinal region 158 or the second heat transfer element 40 .

It is preferably provided that the longitudinal regions 158, 160 are connected in series with one another in terms of fluid mechanics in the first operating mode 62 in relation to the fluid 12 flowing through the refrigeration circuit 10 in the direction of flow 30. Thus, in the first operating mode 62, the heat transfer elements 34, 40 are preferably connected fluidically in series with one another in relation to the fluid 12 flowing through the refrigeration circuit 10 in the direction of flow 30.

It is preferably provided that the longitudinal regions 158, 160 are connected in parallel to one another in terms of flow mechanics in relation to the fluid 12 flowing through the refrigeration circuit 10 in the direction of flow 30 in the second operating mode 64 . Thus, in the second operating mode 62, the heat transfer elements 34, 40 are preferably connected fluidically parallel to one another in relation to the fluid 12 flowing through the refrigeration circuit 10 in the direction of flow 30. Alternatively, it can be provided that the longitudinal regions 158, 160 in the second operating mode 64 relative to the fluid 12 flowing through the refrigeration circuit 10 in the flow direction 30 are connected in series with one another in terms of flow mechanics. Thus, in the second operating mode 64, the heat transfer elements 34, 40 can be connected fluidically in series with one another in relation to the fluid 12 flowing through the refrigeration circuit 10 in the direction of flow 30.

The partial area 178 is preferably designed such that the first inlet 182 can be connected or disconnected fluidically to the first and/or the second and/or the third outlet 184, 188, 194 via the partial area 178. Alternatively or additionally, the partial area 178 is preferably designed such that the second inlet 186 can be connected or disconnected fluidically to the first and/or the second and/or the third outlet 184, 188, 194 via the partial area 178. Alternatively or additionally, the partial area 178 is preferably designed such that the third inlet 192 can be connected or disconnected fluidically to the first and/or the second and/or the third outlet 184, 188, 194 via the partial area 178. For this purpose, the partial area has, for example, a plurality of line elements through which the fluid 12 can flow. The line elements are preferably fluidically connected to one another via respective connection points. In this case, several valve elements are preferably provided in the partial area 178, in particular in the line elements or at the connection points. The respective inlet 182, 186, 192 can be fluidically connected to or separated from the respective outlet 184, 188, 194 by means of the valve elements.

The refrigeration circuit 10 has a compressor 82 through which the fluid 12 can flow, by means of which the fluid 12 can be guided through the refrigeration circuit 10 .

The compressor 82 is preferably designed as an electric compressor. The compressor 82 is arranged in an eighth line section 84 of the refrigeration circuit 10 through which the fluid 12 can flow. The eighth line section 84 is fluidly connected, in particular directly, to the outlet side 20 , in particular to the third through-flow opening 26 .

The refrigeration circuit 10 has a fourth heat transfer element 86 through which the fluid 12 can flow and is formed separately from the heat transfer elements 34, 40, 70, in particular at a distance from the heat transfer elements 34, 40, 70, which is formed as a condenser 88, whereby via the fourth heat transfer element 86 heat 90 from the Refrigeration circuit 10 to a fifth fluid 92 can be discharged. The fifth fluid 92 is preferably air, referred to in particular as heating air, which can be introduced into the vehicle interior for heating the vehicle interior. The heat 90 can thus be dissipated from the fluid 12 flowing through the fourth heat transfer element 86 to the fifth fluid 92 , as a result of which the vehicle interior can be heated by the refrigeration circuit 10 or the fluid 12 . The motor vehicle preferably has an electrical heating system or heating element 94, by means of which the vehicle interior can be heated. The vehicle interior is preferably heated by means of the electric heating element 94 in that heat provided by the electric heating element 94 is transferred to the fluid 92, by means of which the interior is heated. The vehicle interior can thus be heated via the fifth fluid 92 by means of the refrigeration circuit 10, in particular by means of the fourth heat transfer element 86 and/or by means of the electric heating element 94. As a result, the vehicle interior can be heated particularly flexibly, in particular as required.

An inlet 96 of the fourth heat transfer element 86 through which the fluid 12 can flow is fluidically connected, in particular directly, to the eighth line section 84 . The eighth line segment 84 is thus fluidly connected at one end, in particular directly, to the outlet side 20 and at the other end, fluidly connected, in particular directly, to the inlet 96 . As a result, the fluid 12 discharged from the ejector 14, in particular the ejector interior 28, via the outlet side 20 can be introduced into the eighth line section 84, with the fluid 12 flowing through the eighth line section 84 being able to be discharged from the eighth line section 84 via the inlet 96 and can be introduced into the fourth heat transfer element 86 . In the exemplary embodiment, the compressor 82 is arranged downstream of the ejector 14 and upstream of the fourth heat transfer element 86 in relation to the fluid 12 flowing through the eighth line section 84 in the direction of flow 30 .

The fourth heat transfer element 86 has an outlet 98 through which the fluid can flow and which is at a distance from the inlet 96 and via which the fourth heat transfer element 86 is fluidically connected, in particular directly, to the first line section 48 . Thus, the fluid 12 flowing through the fourth heat transfer element 86 can be discharged from the fourth heat transfer element 86 via the outlet 98 and introduced into the first line section 48 . A storage element 100 is arranged in the eighth line section 84 , in particular with respect to the fluid 12 flowing through the eighth line section 84 in the direction of flow 30 , which is arranged upstream of the compressor 82 . The storage element 100 can be understood in particular as a collector or a container. The fluid 12 can thus be stored or collected in the storage element 100 . Below the collector can include a collection volume in which the fluid 12 can be stored or collected.

Preferably, in the first operating mode 62 and/or in the second operating mode 64, the heat transfer elements 34, 40 are fluidically connected to the suction side 16, in particular the first flow opening 22, in such a way that the fluid 12 flowing through the refrigeration circuit 10 in the flow direction 30 from the Outlet side 20, in particular the third through-flow opening 26 of the ejector 14, can be guided or is guided via the heat transfer elements 34, 40 to the suction side 16, in particular the first through-flow opening 22, of the ejector 14 and via the suction side 16, in particular the first through-flow opening 22, in the ejector 14, in particular the ejector interior 28, can be introduced or is introduced. Thus, in the first and/or the second operating mode 62, 64, the fluid 12 flowing through the refrigeration circuit 10 in the direction of flow 30 is discharged from the outlet side 20 of the ejector 14, for example via the line sections 84, 48, 180, 52, 58, 190, preferably under Bypassing the sixth and seventh line sections 78, 196, led to the suction side 16 of the ejector 14. Thus the first

Heat transfer element in the first and / or the second operating mode 62, 64 preferably, in particular directly, arranged on the suction side 16.

In the second operating mode 64, the first and the second heat transfer element 34, 40 are preferably each arranged, in particular directly, on the suction side 16. This can be realized in that the heat transfer elements 34, 40 or the longitudinal regions 158, 160 are flow-mechanically parallel in the second operating mode.

Alternatively or additionally, in the second operating mode 64, it is preferably provided that the fluid 12 flowing through the refrigeration circuit 10 in the direction of flow 30 flows from the outlet side 20, in particular the third flow opening 26 of the ejector 14, via the second heat transfer element 40, bypassing the first heat transfer element 34 the suction side 16, in particular the first throughflow opening 22 of the ejector 14 can be guided or is guided and can be or is introduced via the suction side 16, in particular the first throughflow opening 22, into the ejector 14, in particular the ejector interior 28. Thus, in the second operating mode 64, the fluid 12 flowing through the refrigeration circuit 10 in the direction of flow 30 is discharged from the outlet side 20 of the ejector 14, for example via the line sections 84, 48, 180, 190, bypassing the third and fourth line sections 52, 58, preferably bypassing the sixth and the seventh line section 78, 196, led to the suction side 16 of the ejector 14. The second heat transfer element 40 is thus preferably, in particular directly, arranged on the suction side 16 in the second operating mode 64 .

In the exemplary embodiment shown in Fig. 1, in particular in the first and/or the second operating mode 62, 64, it is preferably provided that the fluid 12 flowing through the refrigeration circuit 10 in the direction of flow 30 flows from the outlet side 20, in particular the third through-flow opening 26 of the ejector 14, via the storage element 100, in particular bypassing the third heat transfer element 70, to the fourth heat transfer element 86 or the heat transfer elements 34, 42 can be guided or is guided. The storage element 100 is therefore arranged on the outlet side 20 or, in particular directly, on the outlet side 20 .

In the first operating mode 62 , heat 74 of the fourth fluid 76 is preferably removed from the fourth fluid 76 via the third heat transfer element 70 and absorbed into the refrigeration circuit or the fluid 12 . Thus, in the first operating mode 62 the battery cooling circuit or the electrical energy store of the motor vehicle can be cooled by means of the cooling circuit 10 .

In its fully manufactured state, the motor vehicle includes a drive train, in particular an electric drive train. The drive train includes an electric machine, by means of which the motor vehicle can be driven.

The drive train, in particular the electric machine, can be cooled by the battery cooling circuit or by the fourth fluid 76 . As a result, heat 74 of the fourth fluid 76 can be dissipated from the battery cooling circuit and the cooling circuit 10 or the fluid 12 via the third heat transfer element 70 are supplied, whereby the drive train, in particular the electric machine, can be cooled. Alternatively or additionally, the drive train, in particular the electric machine, can be cooled by a further cooling circuit which is designed separately from the battery cooling circuit and through which a seventh fluid can flow. The seventh fluid is preferably a coolant. The third heat transfer element can be flowed around or through by the seventh fluid. As a result, heat of the seventh fluid 76 can be removed from the further cooling circuit via the third heat transfer element 70 and fed to the cooling circuit 10 or the fluid 12 . Thus, via the third heat transfer element 70 , heat of the drive train, in particular of the electric machine, referred to in particular as waste heat, can be supplied to the refrigeration circuit. The waste heat can be used, for example, to heat the vehicle interior.

In the second operating mode 64, the waste heat from the drive train, in particular from the electric machine, is preferably fed to the cooling circuit 10 via the third heat transfer element 70, in particular the further cooling circuit and/or the battery cooling circuit. Alternatively or additionally, in the second operating mode 64, waste heat from power electronics of the motor vehicle can be supplied to the cooling circuit 10 via the third heat transfer element 70, in particular the further cooling circuit and/or the battery cooling circuit.

A pressure of the fluid 12 in the eighth line section 84 downstream of the compressor 82 can be referred to in particular as the first pressure p1. A pressure of the fluid 12 in the seventh line section 196, in particular downstream of the third heat transfer element 70, can be referred to in particular as the second pressure p2. A pressure of the fluid 12 in the eighth line section 84 upstream of the compressor 82, in particular upstream of the storage element 100, can be referred to in particular as the third pressure p3. A pressure of the fluid 12 in the fourth line section 58 can be referred to in particular as the fourth pressure p4.

Because the refrigeration circuit 10 has the ejector 14, the second pressure p2, which is present on the drive side 18, and the fourth pressure p4, which can be present on the suction side 16, can be different from one another. The fourth pressure p4 is preferably lower than the second pressure p2. As a result, the refrigeration circuit 10 can be optimized or adapted for a particularly large number of load cases, as a result of which the refrigeration circuit 10 can be used particularly flexibly. In addition, this can The heat 74 introduced into the refrigeration circuit 10 by the fourth fluid 76 via the third heat transfer element 70 or a heat quantity of the heat 74 can be particularly increased, as a result of which the heat quantity of the heat 74 is greater than a heat quantity of the heat 36 which the refrigeration circuit 10 via the first heat transfer element 34 is supplied by the second fluid 38. As a result, the refrigeration circuit 10 can be operated in a load case, referred to in particular as rapid charging, in which the energy store of the motor vehicle has a particularly high cooling requirement, which is greater than a simultaneously occurring cooling requirement of the vehicle interior. Thus, a performance or a refrigeration capacity of the refrigeration circuit 10, in particular in the case of rapid charging, can be particularly increased. The vehicle interior can preferably be cooled by means of the first heat transfer element 34 during the fast charging. In particular, this can be referred to as fast charging with maintenance cooling.

Fast charging is preferably performed while the refrigeration circuit 10 is in the first operating mode 62 .

The first pressure p1 is preferably greater than the third pressure p3, in particular during rapid charging. In other words, the fluid 12 can be increased from the third pressure p3 to the first pressure p1, which is greater than the third pressure p3, as a result of the flow through the compressor 82 as a result of compression effected by the compressor 82. Because the refrigeration circuit 10 has the ejector 14, the third pressure p3 is higher than if the refrigeration circuit 10 did not have the ejector 14. In other words, the third pressure p3 can be particularly increased by means of the ejector 14 . Thus, a pressure difference between the first pressure p1 and the third pressure p3 can be particularly reduced by the ejector 14 . As a result, an electrical output of the compressor 82 for compressing the fluid 12 from the third pressure p3 to the first pressure p1 can be kept particularly low. As a result, the efficiency of the refrigeration circuit 10 can be particularly increased. The motor vehicle can thus be operated particularly efficiently.

During rapid charging, the first pressure p1 is preferably greater than the second pressure p2. The second pressure p2 is preferably greater than the third pressure p3 during rapid charging. The third pressure p3 is preferably greater than the fourth pressure p4 during rapid charging. For example, the second pressure p2 is between 10 and 25 bar, particularly in the case of rapid charging. For example, the third pressure p3 is 3.2 bar, particularly in the case of rapid charging. For example, the fourth pressure p4 is 3 bar, particularly in the case of rapid charging.

During rapid charging, a mass flow of fluid 12 flowing through third heat transfer element 70 is preferably particularly high, in particular greater than a mass flow of fluid 12 flowing through first heat transfer element 34.

In a load case of the refrigeration circuit 10, referred to in particular as a cool down with chiller, the heat quantity of the heat 36 is preferably greater than the heat quantity of the heat 74. The interior of the motor vehicle can be cooled particularly intensively by means of the refrigeration circuit 10 via the first heat transfer element 34. The fluid flow of the fluid 12 flowing through the first heat transfer element 34 is preferably greater than the fluid flow of the fluid 12 flowing through the third heat transfer element 40. The first pressure p1 is preferably greater than the second pressure p2. The second pressure p2 and the third pressure p3 are preferably identical. The ejector 14 is thus deactivated, which can be understood in particular as meaning that no negative pressure for sucking in the fluid 12 via the suction side 16 can be formed in the ejector interior 28 . As a result, the third pressure p4 corresponds to the fourth pressure p4, in particular if pressure losses in the ejector 14 are neglected. A function of the ejector 14 can then be comparable to a function of a simple T-piece.

The refrigeration circuit 10 can have a fifth heat transfer element 102 through which the fluid can flow and which is designed separately from the heat transfer elements 34, 40, 70, 86, in particular at a distance from the heat transfer elements 34, 40, 70, 86, which is designed as an evaporator 104. Heat 106 from a sixth fluid 108 can be supplied to the refrigeration circuit 10 via the fifth heat transfer element 102 . Fluid 12 thus flows through fifth heat transfer element 102 , heat 106 from sixth fluid 108 being supplied to refrigeration circuit 10 or to fluid 12 flowing through fifth heat transfer element 102 via fifth heat transfer element 102 . The sixth fluid 108 is thus cooled by the fluid 12 via the fifth heat transfer element 102 . Preferably, the fifth fluid 108, referred to in particular as cooling air, is air. The cooled cooling air or the cooled sixth fluid 108 is preferably supplied to the vehicle interior for cooling the vehicle interior. In this case, the sixth fluid 108 is preferably introduced into a rear area of the vehicle interior, referred to in particular as the rear area. As a result, the fifth heat transfer element 102 can be referred to in particular as a rear evaporator.

The second fluid 38 cooled by means of the first heat transfer element 34 is preferably introduced into a front area of the vehicle interior, which is arranged in front of the rear area in relation to a driving direction of the motor vehicle.

The refrigeration circuit 10 can have a ninth line section 110 through which the fluid 12 can flow, in which the fifth heat transfer element 102 is arranged. The ninth line section 110 can be fluidically connected to the third line section 52 via a second branch point 112, in particular directly. The second branch point 112 is arranged in the third line section 52 upstream of the first heat transfer element 34 with respect to the fluid 12 flowing through the third line section 52 in the direction of flow 30 . The ninth line section 110 can be fluidically connected, in particular directly, to the fourth line section 58 via an introduction point 114 through which the fluid 12 can flow. The introduction point 114 is preferably arranged in the fourth line section 58 downstream of the first heat transfer element 34 and upstream of the second inlet 186 of the partial area 178 with respect to the fluid 12 flowing through the fourth line section 58 in the direction of flow 30 . Thus, at least part of the fluid flowing through the third line section 52 can be discharged from the third line section 52 via the second branch point 112 and introduced into the ninth line section 110 . The fluid flowing through the ninth line section 110 or the fifth heat transfer element 102 can be discharged from the ninth line section 110 via the introduction point 114 and introduced into the fourth line section 58 .

In a load case, referred to in particular as heat pump operation, of the refrigeration circuit 10, in particular in the first and/or the second operating mode 62, 64, via the first heat transfer element 34 and/or via the second heat transfer element 40 and/or via the third heat transfer element 70 and/or via the fifth heat transfer element 102, the respective heat 36, 68, 74, 106 is transferred to the fluid 12 or is absorbed by the fluid 12 and is released via the fourth heat transfer element 86 to the fifth fluid 92, in particular for heating the vehicle interior. As a result, the vehicle interior can be heated particularly efficiently, in particular in relation to, in particular purely, electrical heating by means of the electrical heating element 94 . In other words, an electrical energy requirement for heating the vehicle interior by means of the refrigeration circuit 10 in the heat pump mode can be lower than an electrical energy requirement for heating the vehicle interior by means of the electric heating element 94. The vehicle interior can thus be heated particularly efficiently.

In particular because the refrigeration circuit 10 has the ejector 14, whereby the second pressure p2 can be greater than the fourth pressure p4, the heat 74 can be absorbed via the third heat transfer element 70 at a higher pressure of the fluid 12 than when the Heat 68 via the second heat transfer element 40 into the fluid 12. As a result, the refrigeration circuit 10 can be operated particularly efficiently during heat pump operation, in particular when the heat quantity of the heat 74 increases be understood as the fourth fluid 76 , the waste heat being transferred into the fluid 12 via the third heat transfer element 70 .

In heat pump operation, a mass flow of fluid 12 flowing through third heat transfer element 70 is preferably particularly high, in particular higher than a mass flow of fluid 12 flowing through second heat transfer element 40, as a result of which ejector 14 can be driven. Alternatively, the mass flow of the fluid 12 flowing through the second heat transfer element 40 and the mass flow of the fluid 12 flowing through the third heat transfer element 70 can be the same in heat pump operation, as a result of which the ejector 14 can be deactivated.

In the heat pump mode, the first pressure p1 is preferably greater than the second pressure p2. In the heat pump mode, the second pressure p2 can be greater than the third pressure p3 or the second pressure p2 and the third pressure p3 can be the same. The second pressure p2 can correspond to 15 bar in heat pump operation. The refrigeration circuit 10 can have an internal heat exchanger 116 that is configured separately from the heat transfer elements 34 , 40 , 70 , 86 , 102 , by means of which heat 118 can be transferred from the third line section 52 to the fourth line section 58 . In other words, the heat 118 can be removed from the fluid flowing through the third line section 52 via the internal heat exchanger 116 and supplied to the fluid 12 flowing through the fourth line section 58 . The internal heat exchanger 116 preferably has a first flow section 120 through which the fluid 12 can flow and a second flow section 122 through which the fluid 12 can flow, spaced apart from the first flow section 120 . The first flow section 120 is preferably arranged in the third line section 52, in particular upstream or downstream of the second branch point 112. The second flow section 122 is preferably arranged in the fourth line section 58, in particular downstream or upstream of the introduction point 114.

A first valve element 136 can be arranged in the first line section 48 , in particular downstream of the first branching point 80 . A second valve element 140 can be arranged in the third line section 52, in particular downstream of the second branch point 112 or downstream of the first flow section 120. A third valve element 142 can be arranged in the ninth line section 110, in particular upstream of the fifth heat transfer element 102. A fourth valve element 144 can be arranged in the seventh line section 196 , in particular upstream of the third heat transfer element 70 .

The fluid can flow through the respective valve element 136, 140, 142, with a respective mass flow of the fluid 12 flowing through the respective valve element 136, 140, 142 or a fluid quantity of the fluid 12 being able to be adjusted by means of the respective valve element 136, 140, 142. At least one of the valve elements 136, 140, 142, in particular all valve elements 136, 140, 142, is preferably designed as an, in particular electronic, expansion valve. A speed of the fluid 12 flowing through the respective expansion valve can be adjusted by means of the respective expansion valve.

A first sensor element 146 can be arranged in the first line section 48, in particular upstream of the first junction point 80. A second sensor element 148 can be arranged in the second line section 180 . In the fourth line section 58, in particular upstream of the first introduction point 114 or the second Flow section 122, a third sensor element 150 may be arranged. A fourth sensor element 152 can be arranged in the seventh line segment 196 , in particular downstream of the third heat transfer element 70 . A fifth sensor element 154 can be arranged in the eighth line section 84 , in particular downstream of the compressor 82 . A sixth sensor element 156 can be arranged in the ninth line section 110, in particular downstream of the fifth heat transfer element 102. The respective sensor element 146, 148, 150, 152, 154, 156 can be designed to detect a respective temperature of the fluid 12 and/or a respective pressure of the fluid 12. In other words, the respective sensor element 146, 148, 150, 152, 154, 156 can be designed as a temperature sensor and/or as a pressure sensor. In particular when the respective sensor element 146, 148, 150, 152, 154, 156 is designed as a temperature sensor and as a pressure sensor, the respective sensor element 146, 148, 150, 152, 154, 156 can be referred to as a combined pressure-temperature sensor.

FIG. 2 shows a schematic partial sectional view of the refrigeration circuit 10 according to a further embodiment, which can in particular be referred to as the second embodiment. The embodiment of the refrigeration circuit 10 shown in FIG. 1 can in particular be referred to as the first embodiment. The second embodiment differs from the first embodiment in particular in that the third heat transfer element 70 is not arranged in the seventh line section 196 . In the second embodiment, the third heat transfer element 70 is arranged in the eighth line section 84, in particular upstream of the compressor 82, for example upstream of the storage element 100. In other words, the third heat transfer element 70 is downstream of the ejector 14, in particular the outlet side 20, and upstream of the first and the first heat transfer element in relation to the flow direction 30 of the fluid 12 flowing from the outlet side 20 to the first and the second heat transfer element 34, 40 34, 40 arranged. As a result, the effectiveness of the ejector 14 is independent of a ratio of the heat quantity of the heat 74 and the heat quantity of the heat 68. In other words, the effectiveness of the ejector 14 is independent of the ratio of the heat 74 and introduced into the fluid 12 via the third heat transfer element 70 the heat 68 introduced via the second heat transfer element 40 into the fluid 12. As a result, the refrigeration circuit 10 can be operated particularly flexibly. This means that in the exemplary embodiment shown in FIG. 2, in particular in the first and/or the second operating mode 62, 64, it is provided that the fluid 12 flowing through the refrigeration circuit 10 in the direction of flow 30 flows from the outlet side 20, in particular the third flow opening 26 of the ejector 14, via the third heat transfer element 70, in particular bypassing the first and the second heat transfer element 34, 40, to the fourth heat transfer element 86 can be guided or is guided. The third heat transfer element is thus arranged on the outlet side 20 or, in particular directly, on the outlet side 20 .

In the exemplary embodiment shown in Fig. 2, the fluid 12 flowing through the refrigeration circuit 10 in the flow direction 30 is preferably supplied by the fourth heat transfer element 86, bypassing the first and/or the second heat transfer element 34, 40, in particular bypassing the second and/or third and / or fifth line section 180, 52, 190 can be guided to the driving side 18 of the ejector 14 and can be introduced via the driving side 18, in particular the second through-flow opening 24, into the ejector 14, in particular into the ejector interior 28.

It is preferably provided in the exemplary embodiment shown in Fig. 2 that in the first operating mode 62 the fluid 12 flowing through the refrigeration circuit 10 in the direction of flow 30 flows from the outlet side 20, in particular via the fourth heat transfer element 86, via the second heat transfer element 40, in particular under Bypassing the first heat transfer element 34, can be or is guided to the driving side 18 of the ejector 14 and can be or is being introduced via the driving side 18, in particular the second through-flow opening 24, into the ejector 14, in particular into the ejector interior 28. Thus, in the first operating mode 62, it is preferably provided that the fluid 12 flowing through the refrigeration circuit 10 in the direction of flow 30 flows from the outlet side 20 via the line sections 84, 48, 180, 196, in particular bypassing the line sections 52, 78, 190 to the Driving side 18 of the ejector 14 can be guided or is guided. This means that the second heat transfer element 40 is preferably, in particular directly, arranged on the drive side 18 in the first operating mode 62 .

In the exemplary embodiment shown in Fig. 2, it is preferably provided that in the second operating mode 64 the refrigeration circuit 10 moves in the direction of flow 30 Fluid 12 flowing through can be guided or is guided from the outlet side 20, in particular via the fourth heat transfer element 86, bypassing the second heat transfer element 40, in particular bypassing the first heat transfer element 34, to the drive side 18 of the ejector 14 and via the drive side 18, in particular the second flow opening 24, in the ejector 14, in particular in the ejector interior 28, can be introduced or is introduced. Thus, in the second operating mode 64, it is preferably provided that the fluid 12 flowing through the refrigeration circuit 10 in the direction of flow 30 flows from the outlet side 20 via the line sections 84, 48, 78, 196, in particular bypassing the line sections 180, 52, 190 to the Driving side 18 of the ejector 14 can be guided or is guided. This means that the fourth heat transfer element 86 is preferably, in particular directly, arranged on the drive side 18 in the second operating mode 64 .

In the second embodiment shown in FIG. 2, the fourth sensor element 152 is arranged in the eighth line section 84, in particular downstream of the third heat transfer element 70 and upstream of the compressor 82.

Claims

55

Claims Refrigeration circuit (10) for a motor vehicle, through which a fluid (12) can flow, with

• one of the fluid (12) through ström Baren ejector (14), which has a suction side (16), a drive side (18) and an outlet side (20), via which the fluid (12) from the ejector (14) can be removed is, wherein the fluid (12) discharged from the ejector (14) via the outlet side (20) and flowing through the refrigeration circuit (10) in a flow direction (30) via the suction side (16) and the drive side (18) into the ejector ( 14) can be initiated,

• at least one first heat transfer element (34) through which the fluid (12) can flow and designed as an evaporator (32), via which heat (36) can be supplied from a second fluid (38) to the refrigeration circuit (10),

• a second heat transfer element (40) through which the fluid (12) can flow and which is formed separately from the first heat transfer element (34) and which can be operated as a condenser (42), whereby heat (44) from the refrigeration circuit via the second heat transfer element (40). (10) can be discharged to a third fluid (46), and

• a third heat transfer element (70) through which the fluid (12) can flow and which is designed separately from the heat transfer elements (34, 40), which is designed as an evaporator (72), whereby the refrigeration circuit (10) via the third heat transfer element (70) heat (76) can be supplied by a fourth fluid (74). 56, characterized in that the first and the second heat transfer element (34, 40) are fluidically connected to the suction side (16) of the ejector (14) in such a way that the fluid (12) flowing through the refrigeration circuit (10) in the direction of flow (30) from the outlet side (20) of the ejector (14) via the first and the second heat transfer element (34, 40) to the suction side (16) of the ejector (14), the second heat transfer element (40) being in a first operating mode (62 ) of the refrigeration circuit (10) can be operated as the condenser (42) and can be operated as an evaporator (66) in a second operating mode (64) of the refrigeration circuit that differs from the first operating mode (62), whereby the refrigeration circuit (10) via the second Heat transfer element (40) heat (68) from the third fluid (46) can be supplied. Refrigeration circuit (10) according to claim 1, characterized in that the refrigeration circuit (10) in the flow direction (30) flowing through fluid (12) from the outlet side (20) bypassing the first heat transfer element (34) and / or the second heat transfer element ( 40) to the driving side (18) of the ejector (14) can be guided. Refrigeration circuit (10) according to Claim 1 or 2, characterized in that the fluid (12) flowing through the refrigeration circuit (10) in the flow direction (30) from the outlet side (20) via the third heat transfer element (70), bypassing the first and/or or the second heat transfer element (34, 40) can be guided to the driving side (18) of the ejector (14). Refrigeration circuit (10) according to one of the preceding claims, characterized in that the third heat transfer element (70) relative to the flow direction (30) of the fluid flowing from the outlet side (20) to the first and second heat transfer element (34, 40). ) is arranged downstream of the ejector (14) and upstream of the first and the second heat transfer element (34, 40). 57 Refrigeration circuit (10) according to one of the preceding claims, characterized in that the first heat transfer element (34) relative to the fluid (12) flowing in the flow direction (30) from the second heat transfer element (40) to the ejector (14) downstream of the second heat transfer element (40) is arranged. Refrigeration circuit (10) according to one of the preceding claims, characterized in that the second heat transfer element (40) is arranged in a first length region (158) of the refrigeration circuit (10) and the first heat transfer element (34) in a second length region (160) of the refrigeration circuit (10) is arranged. Refrigeration circuit (10) according to Claim 6, characterized in that the length regions (158, 160) relative to the fluid (12) flowing through the refrigeration circuit (10) in the direction of flow (30) can be switched either in series with one another in terms of flow mechanics or in parallel with one another in terms of flow mechanics. Refrigeration circuit (10) according to Claim 6 or 7, characterized in that the longitudinal regions (158, 160) in the first operating mode (62) in relation to the fluid (12) flowing through the refrigeration circuit (10) in the direction of flow (30) flow mechanically in series with one another are switched. Refrigeration circuit (10) according to one of Claims 6 to 8, characterized in that the longitudinal regions (158, 160) in the second operating mode (64) in relation to the fluid (12) flowing through the refrigeration circuit (10) in the direction of flow (30) flow-mechanically are connected in parallel to each other. A method for operating one of a fluid (12) through ström Baren refrigeration circuit (10) for a motor vehicle, in which 58

• A fluid (12) flows through an ejector (14) having a suction side (16), a drive side (18) and an outlet side (20), the fluid (12) being discharged from the ejector (14) via the outlet side (20). ) is discharged and the fluid (12) discharged from the ejector (14) via the outlet side (20) and flowing through the refrigeration circuit (10) in a flow direction (30) via the suction side (16) and the drive side (18) into the ejector (14) is initiated,

• the fluid (12) flows through at least one first heat transfer element (34) designed as an evaporator (32), heat (36) being supplied to the refrigeration circuit (10) via the first heat transfer element (34) from a second fluid (38). ,

• the fluid (12) flows through a second heat transfer element (40) which is formed separately from the first heat transfer element (34), the second heat transfer element 40) being operable as a condenser (42), whereby heat ( 44) can be discharged from the refrigeration circuit (10) to a third fluid (46), and

• The fluid (12) flows through a third heat transfer element (70) that is designed separately from the heat transfer elements (34, 40), the third heat transfer element (70) being designed as an evaporator (72), whereby the refrigeration circuit (10) via the third heat transfer element (70) heat (76) is supplied by a fourth fluid (74). characterized in that the fluid (12) flowing through the refrigeration circuit (10) in the flow direction (30) from the outlet side (20) of the ejector (14) via the first and/or the second heat transfer element (34, 40) to the suction side ( 16) of the ejector (14), the second heat transfer element (40) being operated as the condenser (42) in a first operating mode (62) of the refrigeration circuit (10), whereby heat (44) is transferred via the second heat transfer element (40) is discharged from the refrigeration circuit (10) to the third fluid (46), and is operated as an evaporator (66) in a second operating mode (64) of the refrigeration circuit (10) that differs from the first operating mode (62), whereby heat (68) from the third fluid (46) is supplied to the refrigeration circuit (10) via the second heat transfer element (40).