REFRIGERATION SYSTEM

Description

[0001] The invention relates to a refrigeration system with a refrigerant circuit that can be operated for AC operation.

[0002] Electrified vehicles require, in addition to the front evaporator (at least one interior evaporator), a separate coolant circuit for conditioning and temperature control of the energy storage system, which is typically a high-voltage battery. This coolant circuit is coupled to the refrigerant circuit via a heat exchanger, which itself also functions as an evaporator for cooling an intake air stream or as a chiller for cooling water.

[0003] The cooling requirements of high-voltage batteries in electrified vehicles increase disproportionately with the ratio of electrical power input or output to storage capacity (hereinafter referred to as the "power-capacity factor").

[0004] If this power-capacity ratio is low, discharging or charging the battery always takes several hours, and these are referred to as energy cells. Their thermal load is usually so low that special cooling is unnecessary.

[0005] The situation is different with so-called high-performance cells, where both discharging and charging can occur in very short times. Here, due to internal electrical resistance losses, the corresponding power loss and thus heat generation is so high that cooling is necessary. Besides air cooling, which requires additional installation space, cooling with liquid media is becoming increasingly common in automotive technology. Ideally, these fluids flow directly around the battery cells; currently, surface coolers are primarily used. These have a large surface area in contact with the battery cells to be cooled and are themselves cooled by the cooling fluid. The cooling of the cooling fluid is carried out depending on the environmental application. either passively at low ambient temperatures via a fluid cooler to the ambient air in the front end of the vehicle, or actively at higher and high ambient temperatures via a refrigerant evaporator (also called "chiller") that is connected to the refrigeration circuit for the interior air conditioning.

[0006] Of the cooling scenarios described above, the second one, involving high battery cooling demands at high ambient temperatures, requires special consideration. Since the interior cooling demand is also very high at high ambient temperatures, the two demands compete for the maximum available cooling capacity of the refrigeration circuit. It is possible that both the interior and battery cooling demands could each individually reach the maximum available cooling capacity. This would mean that both the interior and the battery would only receive a portion of their required cooling capacity, resulting in reduced interior comfort and further warming of the battery despite cooling. Therefore, the interior climate control could be deactivated to protect components or to ensure the vehicle can continue to be driven.

[0007] KR 2017 0113948 A discloses a refrigeration system with a refrigerant circuit suitable for AC operation. This refrigeration system comprises an air conditioning unit divided into a cold air duct and a hot air duct, each duct being supplied with an airflow by a fan. An evaporator is located in the cold air duct, while the hot air duct contains two condensers connected in series as an air-to-refrigerant heat exchanger. The evaporator with an expansion element, a chiller (refrigerant-to-refrigerant heat exchanger) with an expansion element connected in parallel for cooling a battery, and the two condensers, together with a refrigerant compressor, form the refrigerant circuit.

[0008] Furthermore, this known refrigerant circuit includes an indirect coolant-refrigerant heat exchanger directly downstream of the compressor, with this indirect coolant-refrigerant heat exchanger being connected to a cooler on the coolant side. The refrigerant flowing from this indirect coolant-refrigerant heat exchanger is fed directly to the air-to-refrigerant heat exchangers located in the cold air duct of the air conditioner.

[0009] From EP 1 632 372 A1, a vehicle stationary air conditioning system with a refrigerant circuit is known, comprising at least one refrigerant compressor, a first air-cooled condenser with an associated first fan, and a second air-cooled condenser with an associated second fan. When the vehicle's engine is running, the refrigerant flows through the first air-cooled condenser, which is cooled by the airflow driven by the first fan, but is routed past the second air-cooled condenser via a bypass line. When the vehicle is stationary, the refrigerant flows through the first condenser with the first fan off and then through the second air-cooled condenser with the second fan running.It is also possible to provide a bypass line for the first air-cooled condenser, so that in standby mode the refrigerant is fed directly to the second air-cooled condenser, bypassing the first air-cooled condenser.

[0010] Alternatively, in this well-known vehicle stationary air conditioning system, the two air-cooled condensers can be arranged in a parallel circuit, so that when the vehicle's engine is running, only the first air-cooled condenser and when stationary, only the second air-cooled condenser is supplied with refrigerant.

[0011] DE 10 2014 003 907 A1 describes a refrigerant circuit with an evaporator as an internal heat exchanger, a refrigerant compressor, an air-refrigerant heat exchanger as an external condenser and a heat pump condenser as a heating coil, which together with the evaporator forms an air conditioning unit.

[0012] An air conditioning system for a refrigerant circuit suitable for AC operation, as described in DE 10 2016 007 490 A1 or DE 10 2015 015 125 A1, comprises an evaporator arranged within an air conditioning unit, a refrigerant-to-coolant heat exchanger designed for cooling an electrical component, and a refrigerant compressor, to which an indirect refrigerant-to-coolant heat exchanger is connected. In cooling mode, the refrigerant compressed by the compressor is fed via the indirect refrigerant-to-coolant heat exchanger to an external air-to-refrigerant heat exchanger acting as a refrigerant condenser. In heating mode, the high-pressure compressed refrigerant is not fed to this external air-to-coolant heat exchanger, but instead, after passing through the indirect refrigerant-to-coolant heat exchanger, the refrigerant flows through a heating coil located within the air conditioning unit.This heating coil is followed on the air side by another heating coil, which is thermally connected to the indirect coolant-refrigerant heat exchanger via a coolant circuit.

[0013] An air conditioning system for a vehicle with a refrigerant circuit is also known from DE 10 2014 018 524 A1. This refrigerant circuit comprises an evaporator, a refrigerant compressor, and two indirect coolant-refrigerant heat exchangers downstream of the refrigerant compressor, all arranged in an air conditioning unit. These two indirect coolant-refrigerant heat exchangers are connected in series via an expansion element, enabling two-stage condensation with these two condensers.

[0014] A heat pump with a refrigerant circuit is known from WO 2016 / 118062 A1. This refrigerant circuit comprises an indirect coolant-refrigerant heat exchanger used as an evaporator, which is thermally connected to heat-generating objects via a coolant circuit, a refrigerant compressor, and an indirect coolant-refrigerant heat exchanger as an external condenser, which is connected to heat sinks via a coolant circuit. An expansion device is installed upstream of the indirect coolant-refrigerant heat exchanger used as an evaporator. A portion of the refrigerant, compressed to high pressure by the refrigerant compressor, is fed to a converter, which generates electrical energy from the thermal energy of the refrigerant.After passing through this converter, the refrigerant is fed to an indirect cooler and then, via an expansion device, to the evaporator, whereby the indirect cooler is thermally connected to the coolant circuit containing the heat-generating objects.

[0015] From DE 10 2016 214 119 A1, an air conditioning system for a vehicle with a refrigerant circuit is known, wherein the refrigerant circuit, in addition to the necessary components, includes a heat exchanger designed as a heating coil. This heat exchanger has a filter and an electrical heat exchanger segment constructed from PTC resistance elements. A first air-to-refrigerant heat exchanger segment and a second air-to-refrigerant heat exchanger segment are arranged between the filter and the electrical heat exchanger segment. These two heat exchanger segments can be arranged one above the other or one behind the other with respect to the airflow.

[0016] KR 2017 013700 A describes a refrigeration system for a vehicle with a refrigerant circuit, which is combined with a coolant circuit for cooling the vehicle's traction battery and for cooling electrical components of the powertrain. The refrigerant circuit comprises an evaporator with an associated expansion element for interior cooling, a chiller connected in parallel to the evaporator for battery cooling, a refrigerant compressor, and two external air-to-refrigerant heat exchangers connected in series downstream of the refrigerant compressor. A further external air-to-refrigerant heat exchanger is located within the coolant circuit.

[0017] A refrigerant circuit according to KR 2012 0065027 A comprises an evaporator for interior cooling with an associated expansion device, an external air-to-refrigerant heat exchanger, an internal heat exchanger, and a refrigerant compressor. A first branch after the refrigerant compressor leads to a first refrigerant-to-refrigerant heat exchanger coupled to a refrigerant circuit for cooling a chiller, which can be fluid-connected in parallel to the external air-to-refrigerant heat exchanger. A second branch after the first refrigerant-to-refrigerant heat exchanger leads to a second refrigerant-to-refrigerant heat exchanger, which is connected on the refrigerant side to a cooling circuit for cooling an electric drive motor.

[0018] The object of the invention is to provide a refrigeration system with a refrigerant circuit suitable for AC operation, which on the one hand provides high cooling capacities but on the other hand also has a high (intrinsic) cooling capacity to dissipate the previously absorbed heat; that is, the refrigerant circuit is connected to both a heat source (supply air from the interior, cooling medium of a high-voltage energy storage system) and a heat sink. Furthermore, it is an object of the invention to provide a vehicle with such a refrigeration system.

[0019] The first problem is solved by a refrigeration system with the features of claim 1, the second problem is solved by the features of claim 4.

[0020] A refrigeration system for a vehicle with a refrigerant circuit suitable for AC operation comprises, according to the solution according to the invention: an evaporator used to condition an air supply flow to the vehicle interior, with an associated expansion element; a coolant-refrigerant heat exchanger used to cool an electrical component of the vehicle, with an associated expansion element; a refrigerant compressor; a coolant-refrigerant heat exchanger as an indirect refrigerant condenser or gas cooler, which is thermally coupled on the coolant side to an air-coolant heat exchanger designed as a high-temperature cooler; and an additional coolant-refrigerant heat exchanger as an indirect refrigerant condenser or gas cooler to increase the condensation or gas cooling capacity at maximum cooling capacity of the coolant-refrigerant heat exchanger, which is thermally coupled on the coolant side to an air-coolant heat exchanger designed as a low-temperature cooler.wherein the one coolant-refrigerant heat exchanger and the additional coolant-refrigerant heat exchanger are fluidly connected in a series or parallel connection, and the series or parallel connection of the coolant-refrigerant heat exchanger with the additional coolant-refrigerant heat exchanger is fluidly connected to the high-pressure side of the refrigerant compressor.

[0021] In this refrigeration system according to the invention, two fluid-cooled indirect condensers, designed as coolant-refrigerant heat exchangers, are connected in series or in parallel within the refrigerant circuit. One fluid-cooled condenser is arranged in a high-temperature cooling circuit with an air-coolant heat exchanger downstream of it in terms of heat flow, and the other fluid-cooled condenser is arranged in a low-temperature cooling circuit with a further air-coolant heat exchanger downstream of it in terms of heat flow.

[0022] In accordance with further training, this refrigeration system is characterized by the fact that where one coolant-refrigerant heat exchanger and the additional coolant-refrigerant heat exchanger are arranged in a series circuit fluidly connected in an AC branch, and the AC branch is fluidly connected upstream to the high-pressure side of the refrigerant compressor.

[0023] According to another further development of the invention, the refrigeration system is characterized by the fact that where one coolant-refrigerant heat exchanger is arranged in a first AC branch, the additional coolant-refrigerant heat exchanger is arranged in a second AC branch, and the parallel fluid-connected AC branches are fluid-connected upstream to the high-pressure side of the refrigerant compressor.

[0024] In this refrigeration system according to the invention, two fluid-cooled indirect condensers, designed as coolant-refrigerant heat exchangers, are connected in parallel in the refrigerant circuit. In this arrangement, one fluid-cooled condenser in a high-temperature cooling circuit is connected downstream of an air-coolant heat exchanger with respect to the heat flow, and the other fluid-cooled condenser in a low-temperature cooling circuit is connected downstream of another air-coolant heat exchanger with respect to the heat flow.

[0025] The refrigeration system according to the invention is advantageously used in vehicles.

[0026] Further advantages, features, and details of the invention will become apparent from the claims, the following description of preferred embodiments, and the drawings. These show: Figure 1 shows a refrigeration system with two air-to-refrigerant heat exchangers arranged in series in a refrigerant circuit as a first embodiment, which is not according to the invention and serves only for illustration; Figure 2 shows schematic representations of possible arrangements of two heat exchangers in a vehicle, which are not according to the invention and serve only for illustration; Figure 3 shows a refrigeration system with two air-to-refrigerant heat exchangers arranged in series in a refrigerant circuit as a second embodiment, which is not according to the invention and serves only for illustration; Figure 4 shows a refrigeration system with two air-to-refrigerant heat exchangers arranged in parallel in a refrigerant circuit as a third embodiment, which is not according to the invention and serves only for illustration.Figure 5 shows a refrigeration system with two air-to-refrigerant heat exchangers arranged in parallel in a refrigerant circuit as a fourth embodiment, which is not according to the invention and serves only for illustration; Figure 6 shows a refrigeration system with an outer air-to-refrigerant-to-air heat exchanger arranged in a refrigerant circuit and a coolant-to-refrigerant heat exchanger connected in series with the same fluid as a fifth embodiment, which is not according to the invention and serves only for illustration; Figure 7 shows a refrigeration system with an outer air-to-refrigerant-to-air heat exchanger arranged in a refrigerant circuit and a coolant-to-refrigerant heat exchanger connected in series with the same fluid as a sixth embodiment, which is not according to the invention and serves only for illustration.Figure 8 shows a refrigeration system with an external air-refrigerant-air heat exchanger arranged in a refrigerant circuit and a coolant-refrigerant heat exchanger connected in parallel to the same fluid as a seventh embodiment, which is not according to the invention and serves only for illustration; Figure 9 shows a refrigeration system with two coolant-refrigerant heat exchangers arranged in series in a refrigerant circuit as an eighth embodiment; and Figure 10 shows a refrigeration system with two coolant-refrigerant heat exchangers arranged in parallel in a refrigerant circuit as a ninth embodiment.

[0027] The refrigeration system 1 of a vehicle according to the Figure 1 , 3 , 4 and 5in a refrigerant circuit 2 has two refrigerant condensers or gas coolers, namely a first external air-refrigerant heat exchanger 6.1 and a second external air-refrigerant heat exchanger 6.2, which are fluidly connected in different configurations to the high-pressure outlet of a refrigerant compressor 5 and are installed in the vehicle in different configurations (see Figure 2 are arranged.

[0028] Refrigerant circuit 2 comprises, according to the Figure 1 , 3 , 4 and 5In addition to the refrigerant compressor 5, an evaporator 3 with associated expansion element AE1 is arranged in an evaporator branch 3.1, and a coolant-refrigerant heat exchanger 4, acting as a chiller with associated expansion element AE2, is arranged in a chiller branch 4.1. The chiller serves to condition and temperature-control an energy storage device implemented as a traction battery for an electric or hybrid vehicle. The evaporator branch 3.1 and the chiller branch 4.1 are fluidically connected in parallel, so that the refrigerant of the refrigerant circuit 2 is supplied downstream of these two components 3 and 4 via a low-pressure refrigerant receiver 10 and a low-pressure section of an internal heat exchanger 11 to the low-pressure inlet of the refrigerant compressor 5. Upstream, the parallel connection of the evaporator branch 3.1 and the chiller branch 4.1 is connected via the high-pressure section of the internal heat exchanger 11 to an AC branch 2.1 according to the Figure 1 and 3or with a first AC branch 2.10 and with a second AC branch 2.11 according to the Figures 4 and 5 fluid-connected.

[0029] The two outer air-to-refrigerant heat exchangers 6.1 and 6.2 are located in the AC branch 2.1 of the refrigerant circuit 2 according to the Figure 1 and 3 connected in series, so that the first external air-refrigerant heat exchanger 6.1 is fluidly connected to the high-pressure outlet of the refrigerant compressor 5 and the second external air-refrigerant heat exchanger 6.2 is connected downstream of it.

[0030] These two air-to-refrigerant heat exchangers 6.1 and 6.2 are arranged one after the other, i.e., in series, on the air side of the vehicle such that first the second outer air-to-refrigerant heat exchanger 6.2 is supplied with an external airflow L1 and then the first outer air-to-refrigerant heat exchanger 6.1 is supplied with this airflow L1, as shown schematically in Figure 1As shown, the refrigerant-air flow through the two air-to-refrigerant heat exchangers 6.1 and 6.2 is counterflow. The two air-to-refrigerant heat exchangers 6.1 and 6.2 can each be constructed as a separate component or as a single unit. It is also possible to position the second air-to-refrigerant heat exchanger 6.2 downstream of the first air-to-refrigerant heat exchanger 6.1 on the air side, but this proves to be disadvantageous in terms of system performance.

[0031] Further arrangements of these two air-to-refrigerant heat exchangers 6.1 and 6.2 in a vehicle are described in Figure 2 depicted.

[0032] When arranging the two air-to-refrigerant heat exchangers 6.1 and 6.2 according to the Figures 2a), 2b) and 2c ) are the same on the airside, corresponding to from Figure 1arranged in the vehicle, however, the second outer air-refrigerant heat exchanger 6.2 has a lower height in the vehicle's vertical direction (z-direction) than the first outer air-refrigerant heat exchanger 6.1. After Figure 2a ) or Figure 2b The second outer air-refrigerant heat exchanger 6.2, viewed in the vertical direction of the vehicle, is aligned with the upper or lower edge of the first outer air-refrigerant heat exchanger 6.1. The resulting free space in the plane of the second outer air-refrigerant heat exchanger 6.2 allows for the installation of additional radiators for the vehicle.

[0033] In the arrangement according to Figure 2c ) the second external air-refrigerant heat exchanger 6.2, with its lower height compared to the first external air-refrigerant heat exchanger 6.1, is placed centrally or arbitrarily in relation to the height of the first external air-refrigerant heat exchanger 6.1 in the vehicle's vertical direction.

[0034] When arranging the two air-to-refrigerant heat exchangers 6.1 and 6.2 according to the Figures 2d) and 2e These are arranged one above the other in the vehicle's vertical direction (z-direction) so that an airflow L1 flows through them in parallel on the air side. Figure 2d ) is the first external air-refrigerant heat exchanger 6.1 above the second external air-refrigerant heat exchanger 6.2, according to Figure 2e ) however, it is arranged below the second outer air-to-refrigerant heat exchanger 6.2. According to arrow R, in the arrangement according to Figure 2d) and Figure 2e ) first the first external air-refrigerant heat exchanger 6.1 is filled with refrigerant and then the second external air-refrigerant heat exchanger 6.2.

[0035] When arranging the two air-to-refrigerant heat exchangers 6.1 and 6.2 according to Figure 2fThe same components are arranged side-by-side in the yz plane in the transverse direction of the vehicle (y-direction) and are thus also subjected to a parallel airflow on the air side. Furthermore, in this arrangement as well, the first outer air-refrigerant heat exchanger 6.1 and subsequently the second outer air-refrigerant heat exchanger 6.2 are supplied with refrigerant (see directional arrows R).

[0036] Finally, the following also apply in the refrigerant circuit 2 of the refrigeration system 1 according to Figure 3 The two outer air-to-refrigerant heat exchangers 6.1 and 6.2 are arranged in series in the AC branch 2.1. This is shown in the special spaced-apart representation of these two air-to-refrigerant heat exchangers 6.1 and 6.2 in Figure 3The arrangement of these components is shown in a front apron in the area of ​​a left air intake and a right air intake. This means, for example, that the first outer air-refrigerant heat exchanger 6.1 is supplied with a first airflow L1 in the area of ​​the right side of the vehicle, while the second outer air-refrigerant heat exchanger 6.2 is supplied with a second airflow L2 in the area of ​​the left side of the vehicle, or vice versa.

[0037] Similarly, the two outer air-refrigerant heat exchangers 6.1 and 6.2 can also be arranged in air inlets in the rear of the vehicle, e.g. in vehicles with a mid- or rear-mounted engine.

[0038] According to the Figures 4 and 5The two outer air-to-refrigerant heat exchangers 6.1 and 6.2 are arranged in a first AC branch 2.10 and in a second AC branch 2.11, wherein these two AC branches 2.10 and 2.11 are fluidically connected in parallel. In the arrangement of the two outer air-to-refrigerant heat exchangers 6.1 and 6.2 according to Figure 4 The same components are traversed serially on the air side by an airflow L1, whereby the second outer air-refrigerant heat exchanger 6.2 is first exposed to the airflow L1, followed by the first outer air-refrigerant heat exchanger 6.1. It is also possible to arrange the second air-refrigerant heat exchanger 6.2 downstream of the first air-refrigerant heat exchanger 6.1.

[0039] Even with this parallel arrangement of the two outer air-refrigerant heat exchangers 6.1 and 6.2 on the refrigerant side, a configuration of the second outer air-refrigerant heat exchanger 6.2 according to Figures 2a) to 2c) is possible, whereby the second outer air-refrigerant heat exchanger 6.2 has a lower height compared to the first outer air-refrigerant heat exchanger 6.1 when viewed in the vehicle's vertical direction (z-direction). Furthermore, it is also possible to stack these two outer air-refrigerant heat exchangers 6.1 and 6.2 one above the other, also viewed in the vehicle's vertical direction (z-direction), as shown in the illustrations. Figure 2d) and 2e ) or side by side after Figure 2f to order.

[0040] Finally, the two outer air-to-refrigerant heat exchangers 6.1 and 6.2 are also located in the refrigerant circuit 2 of the refrigeration system 1 according to Figure 5arranged in parallel by means of the two AC branches 2.10 and 2.11. With the special spaced-apart representation of these two air-to-refrigerant heat exchangers 6.1 and 6.2 in Figure 5 The arrangement of these components is shown in a front apron in the area of ​​a left and right air intake. This means, for example, that the first outer air-refrigerant heat exchanger 6.1 is supplied with a first airflow L1 in the area of ​​the right side of the vehicle, while the second outer air-refrigerant heat exchanger 6.2 is supplied with a second airflow L2 in the area of ​​the left side of the vehicle, or vice versa.

[0041] Similarly, the two outer air-refrigerant heat exchangers 6.1 and 6.2 can also be arranged in air inlets in the rear of the vehicle, e.g. in vehicles with a mid- or rear-mounted engine.

[0042] The additional air-to-refrigerant heat exchanger 6.2 of the refrigerant circuit 2 according to the Figure 1 , 3 , 4 and 5 It can be continuously flowed through or, using a bypass line and a suitable valve, the flow can be controlled situationally. In the case of a refrigerant-side shutdown, it is also possible to implement a controllable air-side closure.

[0043] Even in the variants of the parallel arrangement of the air-refrigerant heat exchangers 6.1 and 6.2 according to the Figures 4 and 5 By additionally considering valves upstream and downstream of the respective heat exchangers, only partial application of refrigerant to these air-refrigerant heat exchangers 6.1 and / or 6.2 is possible.

[0044] The sensors in refrigerant circuit 2 are as follows: Figure 1 , 3 , 4 and 5 Several pressure and temperature sensors are provided for controlling and regulating the system.

[0045] Thus, the refrigerant compressor 5 is assigned a first pressure-temperature sensor pT1 at the high-pressure outlet, furthermore a second pressure-temperature sensor pT2 at the outlet of the low-pressure refrigerant receiver 10, and a third pressure-temperature sensor pT3 at the outlet of the second external air-refrigerant heat exchanger 6.2 according to the Figure 1 and 3 or downstream after the parallel connection of the two AC branches 2.10 and 2.11, and finally a fourth pressure-temperature sensor pT4 is arranged at the low-pressure-side outlet of the coolant-refrigerant heat exchanger 4. Alternatively to the pressure-temperature sensor pT3 in the refrigerant circuit 2 according to the Figures 3 and 4 A pressure-temperature sensor pT3.1 can be used in the first AC branch 2.10 and a pressure-temperature sensor pT3.2 in the second AC branch 2.11.

[0046] The first pressure-temperature sensor pT1 of the refrigerant circuit 2 serves to determine the refrigerant temperature and the high pressure of the compressed medium at the outlet of the refrigerant compressor 5. The detection of these two quantities serves to monitor the maximum permissible mechanical and thermal loads of the refrigeration system, specifically at the outlet of the refrigerant compressor 5, and, if necessary, to limit system operation by means of control measures requested by a control unit, e.g., an air conditioning control unit, in order not to exceed the permissible maximum values.

[0047] The second pressure-temperature sensor pT2 of the refrigerant circuit 2 serves to detect underfilling, but also to set and monitor a required low pressure.

[0048] The third pressure-temperature sensor pT3 of the refrigerant circuit 2, provided at the outlet side of the second outer air-refrigerant heat exchanger 6.2, according to the Figure 1 and3 Its primary purpose is for setting up or

[0049] Monitoring of the system operating parameters "optimal high pressure" during supercritical system operation and "subcooling after the second external air-refrigerant heat exchanger 6.2" during subcritical system operation. The same applies to the third pressure-temperature sensor pT3 of the refrigerant circuit 2, provided for the parallel connection of the two air-refrigerant heat exchangers 6.1 and 6.2, according to the Figures 4 and 5 , as well as for the alternative pressure-temperature sensors pT3.1 and pT3.2.

[0050] The fourth pressure-temperature sensor pT4 of the refrigerant circuit 2 serves to monitor and control the degree of superheat at the outlet of the coolant-refrigerant heat exchanger 4, which is used as a chiller.

[0051] In this refrigerant circuit 2 according to the Figure 1 , 3 , 4 and 5The additional external air-refrigerant heat exchanger 6.2 generates an increased condensation or gas cooling capacity, which is required with a high maximum battery cooling capacity of the coolant-refrigerant heat exchanger 4 as a chiller and, if necessary, also with an increased compressor capacity of the refrigerant compressor 5 adapted accordingly.

[0052] The refrigeration system 1 of a vehicle according to the Figure 6 , 7 and 8 in a refrigerant circuit 2 has an air-cooled refrigerant condenser or gas cooler and a fluid-cooled refrigerant condenser or gas cooler, namely an external air-to-refrigerant heat exchanger 6 and a coolant-to-refrigerant heat exchanger 7 as an indirect refrigerant condenser or gas cooler, which are fluidly connected in different configurations to the high-pressure outlet of a refrigerant compressor 5.

[0053] Refrigerant circuit 2 comprises, according to the Figure 6 , 7 and 8 In addition to the refrigerant compressor 5, an evaporator 3 with associated expansion element AE1 is arranged in an evaporator branch 3.1, and a refrigerant-coolant heat exchanger 4, arranged as a chiller with associated expansion element AE2, is arranged in a chiller branch 4.1. The evaporator branch 3.1 and the chiller branch 4.1 are fluidically connected in parallel, so that the refrigerant of the refrigerant circuit 2 is supplied downstream of these two components 3 and 4 via a low-pressure refrigerant receiver 10 and a low-pressure section of an internal heat exchanger 11 to the low-pressure inlet of the refrigerant compressor 5. Upstream, the parallel connection of the evaporator branch 3.1 and the chiller branch 4.1 is connected via the high-pressure section of the internal heat exchanger 11 to an AC branch 2.1 according to the Figure 6 and 7 or with a first AC branch 2.10 and with a second AC-AC branch 2.11 according to Figure 8fluid-connected.

[0054] The external air-to-refrigerant heat exchanger 6 as a refrigerant condenser or gas cooler and the coolant-to-refrigerant heat exchanger 7 as an indirect refrigerant condenser or indirect gas cooler are in the AC branch 2.1 of the refrigerant circuit 2 according to Figure 6 serially fluid-connected, so that the outer air-refrigerant heat exchanger 6 is fluidly connected to the high-pressure outlet of the refrigerant compressor 5 and the coolant-refrigerant heat exchanger 7 is connected downstream of it.

[0055] The coolant-refrigerant heat exchanger 7 is integrated into a low-temperature circuit 7.0 of an air-coolant heat exchanger 8 designed as a low-temperature cooler. The waste heat from the coolant-refrigerant heat exchanger 7 is thus first transferred to the coolant of the low-temperature circuit 7.0 and from there, via the air-coolant heat exchanger 8, to an airflow L1. With respect to the direction of heat flow, the air-coolant heat exchanger 8 is therefore downstream of the coolant-refrigerant heat exchanger 7.

[0056] Is the refrigerant circuit 2 according to Figure 6The coolant-refrigerant heat exchanger 7, which is connected as the second condenser or gas cooler downstream of the outer air-refrigerant condenser 6 (the first condenser or gas cooler), can either be continuously flowed through this coolant-refrigerant heat exchanger 7 or, by means of a bypass line and a suitable valve, have flow around it as needed. It is also possible to switch off a pump provided in the low-temperature circuit 7.0, provided that the coolant in the coolant-refrigerant heat exchanger 7 does not boil.

[0057] The refrigeration system 1 according to Figure 6 It also features a further air-coolant heat exchanger 9 designed as a high-temperature cooler, which serves to transfer the heat from components that can operate at a higher temperature level, such as an electric motor or, in the case of PHEV vehicles, possibly also an internal combustion engine, to the ambient air or the ambient airflow L1.

[0058] Also in the case of refrigerant circuit 2 according to Figure 7 The external air-to-refrigerant heat exchanger 6 and the coolant-to-refrigerant heat exchanger 7 are connected in series as an indirect refrigerant condenser or indirect gas cooler in the AC branch 2.1, but in comparison to the arrangement according to Figure 6 in reverse order, so that the coolant-refrigerant heat exchanger 7 is fluidly connected to the high-pressure outlet of the refrigerant compressor 5 and the external air-refrigerant heat exchanger 6 is connected downstream of it.

[0059] This coolant-refrigerant heat exchanger 7 also uses refrigerant 2. Figure 7is integrated into a low-temperature circuit 7.0 of an air-coolant heat exchanger 8 designed as a low-temperature cooler. The waste heat from the coolant-refrigerant heat exchanger 7 is thus first transferred to the coolant of the low-temperature circuit 7.0 and from there, via the air-coolant heat exchanger 8, to an airflow L1. With regard to the direction of heat flow, the air-coolant heat exchanger 8 is therefore downstream of the coolant-refrigerant heat exchanger 7.

[0060] Is the refrigerant circuit 2 according to Figure 7The refrigerant-coolant heat exchanger 7, which is thermally coupled to the air-coolant heat exchanger 8 and serves as the first condenser or gas cooler, and the air-coolant heat exchanger 6, which serves as the second condenser or gas cooler, can either be continuously flowed through the air-coolant heat exchanger 6 or have a bypass line and a suitable valve to allow flow around it as needed. In the event of a refrigerant-side shutdown, it is also possible to implement a controllable air-side closure.

[0061] The coolant-refrigerant heat exchanger 7 can be thermally coupled to an air-coolant heat exchanger 9, designed as a high-temperature cooler, via a schematically indicated high-temperature circuit 9.0, instead of being thermally coupled to the air-coolant heat exchanger 8, which is designed as a low-temperature cooler. In this case, ideally, a bypass line 2.2 flowing around the coolant-refrigerant heat exchanger 7 is also provided (in Figure 7(shown in dashed lines) is provided with a corresponding valve element so that, in the event of a temperature in the high-temperature circuit exceeding the refrigerant temperature, further heating of the refrigerant is prevented. Alternatively, the coolant-refrigerant heat exchanger 7 can also be bypassed on the water side, or standing water can be ensured in the coolant-refrigerant heat exchanger 7 to prevent heat transfer to the refrigerant. The situation of "boiling water" must be taken into account in such a case.

[0062] In the refrigerant circuit according to the Figure 6 and 7The outer air-refrigerant heat exchanger 6 is arranged on the air side between the air-coolant heat exchanger 8 and the air-coolant heat exchanger 9, so that first the low-temperature cooler, then the air-refrigerant heat exchanger 6 and finally the high-temperature cooler are supplied with an airflow L1.

[0063] The refrigerant circuit 2 of the refrigeration system 1 according to Figure 8 It also features an external air-to-refrigerant heat exchanger 6 and a coolant-to-refrigerant heat exchanger 7 as an indirect refrigerant condenser or indirect gas cooler, which, however, in contrast to the refrigerant circuit 2, are located according to Figure 6 and Figure 7The fluid connections are not serial, but parallel. For this purpose, the outer air-refrigerant heat exchanger 6 is arranged in a first AC branch 2.10 and the coolant-refrigerant heat exchanger 7 in a second AC branch 2.11, wherein these two AC branches 2.10 and 2.11 are fluid-connected in parallel and are fluid-connected upstream with the high-pressure outlet of the refrigerant compressor 5 and downstream via the high-pressure section of the inner heat exchanger 11 with the parallel-connected evaporator branch 3.1 and chiller branch 4.1.

[0064] According to the Figure 6 , 7 and 8 The air-coolant heat exchanger 8 can be arranged not only in front of the outer air-coolant heat exchanger 6, but also directly after, below, above or laterally in one of the two skirts of the vehicle, instead of being arranged on the air side.

[0065] In the refrigerant circuit 2 according to Figure 8The coolant-refrigerant heat exchanger 7 is integrated into a low-temperature circuit 7.0 of an air-coolant heat exchanger 8 designed as a low-temperature cooler. Here, the air-coolant heat exchanger 8 and the outer air-coolant heat exchanger 6 are arranged one behind the other on the air side of the vehicle, so that first the air-coolant heat exchanger 8 and then the outer air-coolant heat exchanger 6 are subjected to an airflow L1.

[0066] The coolant-refrigerant heat exchanger 7 can be thermally coupled to an air-coolant heat exchanger 9, designed as a high-temperature cooler, via a high-temperature circuit 9.0, instead of being thermally coupled to the air-coolant heat exchanger 8, which is designed as a low-temperature cooler. In this case, a bypass line 2.2 bypassing the coolant-refrigerant heat exchanger 7 (in Figure 8(shown in dashed lines) is provided with a corresponding valve element to prevent further heating of the refrigerant in the event of a temperature occurring in the high-temperature circuit that is greater than the temperature of the refrigerant.

[0067] The air-to-coolant heat exchanger 8 is located downstream of the outer air-to-refrigerant heat exchanger 6 on the air side. Alternatively, instead of a bypass 2.2 around the coolant-to-refrigerant heat exchanger 7, the entire second AC branch 2.11 can be closed, thus directing the refrigerant completely through the first AC branch 2.10 and the air-to-refrigerant heat exchanger 6. Appropriate shut-off or switching valves and check valves must be provided.

[0068] In this refrigerant circuit 2 according to the Figure 6 , 7 and 8The additional coolant-refrigerant heat exchanger 7 generates an increased condensation or gas cooling capacity, which is required when the coolant-refrigerant heat exchanger 4 has a high maximum battery cooling capacity as a chiller and, if necessary, when the refrigerant compressor 5 has an increased compressor capacity adapted to this.

[0069] The sensors in refrigerant circuit 2 are as follows: Figure 6 , 7 and 8 Several pressure and temperature sensors are provided for controlling and regulating the system.

[0070] Thus, the refrigerant compressor 5 is assigned a first pressure-temperature sensor pT1 at the high-pressure outlet, furthermore a second pressure-temperature sensor pT2 at the outlet of the low-pressure refrigerant receiver 10, and a third pressure-temperature sensor pT3 at the outlet of the indirect coolant-refrigerant heat exchanger 7 according to Figure 6 or at the outlet of the air-refrigerant heat exchanger 6 according to Figure 7 and finally a fourth pressure-temperature sensor pT4 is arranged at the low-pressure side outlet of the coolant-refrigerant heat exchanger 4. The function of these pressure-temperature sensors is identical to those used in connection with the refrigerant circuit 2 according to the Figure 1 , 3 , 4 and 5 were explained.

[0071] For a wiring configuration according to Figure 8 Either each of the heat exchangers 6 and 7 has its own sensors pT3.1 and pT3.2 connected downstream, or a common sensor pT3 is arranged downstream of the merging of the two AC branches 2.10 and 2.11.

[0072] The refrigeration system 1 of a vehicle according to the Figure 9 and 10In a refrigerant circuit 2, two fluid-cooled indirect refrigerant condensers or gas coolers are included, namely a coolant-refrigerant heat exchanger 7.1 and an additional coolant-refrigerant heat exchanger 7.2, which are fluidly connected to the high-pressure outlet of a refrigerant compressor 5 in different configurations.

[0073] Refrigerant circuit 2 comprises, according to the Figure 9 and 10In addition to the refrigerant compressor 5, an evaporator 3 with associated expansion element AE1 is arranged in an evaporator branch 3.1, and a refrigerant-coolant heat exchanger 4, arranged as a chiller with associated expansion element AE2, is arranged in a chiller branch 4.1. The evaporator branch 3.1 and the chiller branch 4.1 are fluidically connected in parallel, so that the refrigerant of the refrigerant circuit 2 is supplied downstream of these two components 3 and 4 via a low-pressure refrigerant receiver 10 and a low-pressure section of an internal heat exchanger 11 to the low-pressure inlet of the refrigerant compressor 5. Upstream, the parallel connection of the evaporator branch 3.1 and the chiller branch 4.1 is connected via the high-pressure section of the internal heat exchanger 11 to an AC branch 2.1 according to Figure 9 or with a first AC branch 2.10 and with a second AC branch 2.11 according to Figure 10 fluid-connected.

[0074] The two coolant-refrigerant heat exchangers 7.1 and 7.2, acting as indirect refrigerant condensers or indirect gas coolers, are located in the AC branch 2.1 of the refrigerant circuit 2 according to Figure 9 connected in series, so that the coolant-refrigerant heat exchanger 7.1 is fluidly connected to the high-pressure outlet of the refrigerant compressor 5 and the additional coolant-refrigerant heat exchanger 7.2 is connected downstream of it.

[0075] In the refrigerant circuit 2 according to Figure 9The coolant-refrigerant heat exchanger 7.1 is integrated into a high-temperature circuit 8.20 of an air-to-coolant heat exchanger 8.2 designed as a high-temperature cooler, while the other coolant-refrigerant heat exchanger 7.2 is integrated into a low-temperature circuit 8.10 of an air-to-coolant heat exchanger 8.1 designed as a low-temperature cooler. This allows heat from the evaporator branch 3.1 and / or chiller branch 4.1 to be dissipated to the vehicle environment via an airflow L1 across two temperature levels. Components 8.1 and 8.2 are arranged in series on the air side, so that the airflow L1 first passes through the air-to-coolant heat exchanger 8.1 and then through the air-to-refrigerant heat exchanger 8.2.

[0076] In a further embodiment, both indirect coolant-refrigerant heat exchangers 7.1 and 7.2 can be integrated into the low-temperature circuit 8.10; however, on the coolant side, the coolant-refrigerant heat exchanger 7.1 should be flowed through first, followed by the additional coolant-refrigerant heat exchanger 7.2, in series, in order to achieve the optimal cooling effect (in Figure 9 (not shown).

[0077] The refrigerant circuit 2 of the refrigeration system 1 according to Figure 10 also features a coolant-refrigerant heat exchanger 7.1 and an additional coolant-refrigerant heat exchanger 7.2 as indirect refrigerant condensers or indirect gas coolers, which, however, unlike the refrigerant circuit 2, are located according to Figure 9The fluid connections are not serial, but parallel. For this purpose, the coolant-refrigerant heat exchanger 7.1 is arranged in a first AC branch 2.10 and the additional coolant-refrigerant heat exchanger 7.2 in a second AC branch 2.11, wherein these two AC branches 2.10 and 2.11 are fluid-connected in parallel and are fluid-connected upstream with the high-pressure outlet of the refrigerant compressor 5 and downstream via the high-pressure section of the inner heat exchanger 11 with the parallel-connected evaporator branch 3.1 and chiller branch 4.1.

[0078] In the refrigerant circuit 2 according to Figure 10 Both the single and the additional coolant-refrigerant heat exchangers 7.1 and 7.2 are integrated into a low-temperature circuit 8.10 of an air-coolant heat exchanger 8.1 designed as a low-temperature cooler. The coolant flows through both coolant-refrigerant heat exchangers 7.1 and 7.2 in series on the coolant side.

[0079] Alternatively, it is also possible that only the additional coolant-refrigerant heat exchanger 7.2 is thermally coupled to the air-coolant heat exchanger 8.1, while the coolant-refrigerant heat exchanger 7.1 is thermally coupled to an air-coolant heat exchanger 8.2 designed as a high-temperature cooler via a corresponding high-temperature cooling circuit (in Figure 10 (not shown). In this case, a bypass line flowing around the coolant-refrigerant heat exchanger 7.1 (in Figure 10 (not shown) is provided with a corresponding valve element so that, in the event of a temperature occurring in the high-temperature circuit that is greater than the temperature of the refrigerant, further heating of the refrigerant is avoided.

[0080] Alternatively, a water-side bypass can be provided, stagnant water can be set, or one of the two refrigerant-carrying AC branches 2.10 or 2.11 can be completely and temporarily deactivated. Suitable shut-off, diverter, and check valves must be provided for this purpose.

[0081] In this refrigerant circuit 2 according to the Figure 9 and 10 The additional indirect coolant-refrigerant heat exchanger 7.2 generates an increased condensation or gas cooling capacity, which is required with a high maximum battery cooling capacity of the coolant-refrigerant heat exchanger4 as a chiller and, if necessary, also with an increased compressor capacity of the refrigerant compressor 5 adapted to this.

[0082] The sensors in refrigerant circuit 2 are as follows: Figure 9 and 10Several pressure and temperature sensors are provided for controlling and regulating the system.

[0083] Thus, the refrigerant compressor 5 is assigned a first pressure-temperature sensor pT1 at the high-pressure outlet, furthermore a second pressure-temperature sensor pT2 at the outlet of the low-pressure refrigerant collector 10, a third pressure-temperature sensor pT3 at the outlet of the indirect coolant-refrigerant heat exchanger 7.2 (see Figure 9 ) and finally a fourth pressure-temperature sensor pT4 is arranged at the low-pressure side outlet of the coolant-refrigerant heat exchanger 4. The function of these pressure-temperature sensors is identical to those used in connection with the refrigerant circuit 2 according to the Figure 1 , 3 , 4 and 5 were explained.

[0084] In the refrigerant circuit 2 according to Figure 10Either each of the indirect heat exchangers 7.1 and 7.2 has its own sensors pT3.1 and pT3.2 connected downstream, or a common sensor pT3 is arranged downstream of the merging of the two AC branches 2.10 and 2.11.

[0085] In summary, the following applies to the refrigeration systems 1 according to the Figures 1 to 10 The following advantages are achieved: High, sustained charging capacities are achieved, especially fast charging with charging times well under half an hour, without the corresponding high-voltage traction battery heating up significantly. When the high-voltage battery requires high cooling capacity, its cooling is ensured. Therefore, there is a time delay in the reduction of the performance of the interior climate control or battery cooling. When the high-voltage battery requires high cooling capacity, its cooling is ensured without, ideally, restricting or disabling interior comfort during charging, whether driving or stationary. An acoustic improvement compared to known systems is achieved due to the lower air velocities and thus reduced flow noise resulting from the additional cooling surfaces of the second capacitors.

[0086] For the sake of simplicity, the embodiments of the invention according to the Figure 9 and 10 A pure refrigeration system with a refrigerant receiver located on the low-pressure side 10. Furthermore, more complex system configurations with additional evaporators and heat pump functionality are possible. The refrigerant storage can also be repositioned from the low-pressure to the high-pressure side, particularly when using purely subcritical refrigerants. REFERENCE MARK:

[0087] 1 Refrigeration system 2 Refrigerant circuit of the refrigeration system 1 2.1 AC branch of the refrigerant circuit 2 2.10 First AC branch of the refrigerant circuit 2 2.11 Second AC branch of the refrigerant circuit 2 3 Evaporator of the refrigerant circuit 2 3.1 Evaporator branch 4 Refrigerant-to-refrigerant heat exchanger (also called chiller) of the refrigerant circuit 2 4.0 Refrigerant circuit of the refrigerant-to-refrigerant heat exchanger 4 4.1 Chiller branch 5 Refrigerant compressor 6. Outer air-to-refrigerant heat exchanger of the coolant circuit 2 6.1 First outer air-to-refrigerant heat exchanger of the coolant circuit 2 6.2 Second outer air-to-refrigerant heat exchanger 7 Coolant-to-refrigerant heat exchangers of coolant circuit 2 7.0 Low-temperature circuit 7.1 First coolant-to-refrigerant heat exchanger of coolant circuit 2 7.2 Second coolant-to-refrigerant heat exchanger of coolant circuit 2 8 Air-to-coolant heat exchangers of the refrigerant circuit 2 8.1 First air-to-coolant heat exchanger of the refrigerant circuit 2 8.10 Low-temperature circuit 8.2 Second air-to-coolant heat exchanger of the refrigerant circuit 2 8.20 High-temperature circuit 9 Air-to-coolant heat exchangers of the refrigerant circuit 2 9.0 High-temperature circuit 10 Low-pressure refrigerant receiver AE1 Evaporator expansion valve 3 AE2 Coolant-refrigerant heat exchanger expansion valve 4 L1 Airflow L2 Airflow Directional arrow for refrigerants

Claims

1. Refrigeration system (1) for a vehicle having a refrigerant circuit (2) operable for AC operation, comprising: - an evaporator (3) used for conditioning an inlet air stream supplied to the vehicle interior and having an associated expansion element (AE1), - a coolant / refrigerant heat exchanger (4) used for cooling an electrical component of the vehicle and having an associated expansion element (AE2), - a refrigerant compressor (5), - a coolant / refrigerant heat exchanger (7.1) as an indirect refrigerant condenser or gas cooler which on the coolant side is thermally coupled to an air / coolant heat exchanger (8.2) configured as a high-temperature cooler, and - an additional coolant / refrigerant heat exchanger (7.2) as an indirect refrigerant condenser or gas cooler for increasing the condensation or gas cooling performance in the case of maximum cooling performance of the coolant / refrigerant heat exchanger (4), which on the coolant side is thermally coupled to an air / coolant heat exchanger (8.1) configured as a low-temperature cooler, characterized in that - the one coolant / refrigerant heat exchanger (7.1) and the additional coolant / refrigerant heat exchanger (7.2) are fluid-connected in a series connection or in a parallel connection in an AC branch (2.1), and - the series connection or the parallel connection of the coolant / refrigerant heat exchanger (7.1) with the additional coolant / refrigerant heat exchanger (7.2) is fluid-connected to the high-pressure side of the refrigerant compressor (5).

2. Refrigeration system (1) according to claim 1, in which - the one coolant / refrigerant heat exchanger (7.1) and the additional coolant / refrigerant heat exchanger (7.2) are fluid-connected in a series connection arranged in an AC branch (2.1), and - the AC branch (2.1) is fluid-connected upstream to the high-pressure side of the refrigerant compressor (5).

3. Refrigeration system (1) according to claim 1, in which - the one coolant / refrigerant heat exchanger (7.1) is arranged in a first AC branch (2.10), - the additional coolant / refrigerant heat exchanger (7.2) is arranged in a second AC branch (2.11), and - the parallel fluid-connected AC branches (2.10, 2.11) are fluid-connected upstream to the high-pressure side of the refrigerant compressor (5).

4. Vehicle having a refrigeration system according to any one of claims 1 to 3.