DE102019216925A1 - Temperature control system for a motor vehicle - Google Patents

Abstract

The invention relates to a temperature control system (1) for a motor vehicle (2),
- With a coolant circuit (3) in which a coolant (4) flows,
- With a refrigerant circuit (5), in which a refrigerant (6) flows,
- A coolant cooler (7), a chiller (8), at least one component (9) to be temperature-controlled and a first coolant pump (10) are arranged in the coolant circuit (3),
- A condenser (11), the chiller (8), an evaporator (12) and a compressor (13) for compressing the refrigerant (6) are arranged in the refrigerant circuit (5).
It is essential to the invention that a first coolant bypass line (14) which bypasses the chiller (8) is provided, in which a first valve device (15) is arranged which, depending on the flow of coolant flowing through the chiller (8) and the first coolant bypass line (14) a coolant temperature on the chiller outlet side controls or regulates.

Description

The present invention relates to a temperature control system for a motor vehicle with a cooling circuit and a refrigerant circuit according to the preamble of claim 1. The invention also relates to an electric vehicle with a vehicle cabin and such a temperature control system.

In battery-electric vehicles, a refrigerant circuit is used to cool cabin air on an evaporator and to cool a low-temperature circuit in a chiller. The target temperature at the chiller differs significantly from that of the evaporator, however, a target temperature of 25 to 35 ° C. is aimed for for the chiller that cools or tempers the coolant for a vehicle battery. For the evaporator for cooling the cabin air, however, a target temperature of 2 to 10 ° C or a maximum of 12 ° C is aimed for. Both heat exchangers, i.e. the chiller and the evaporator, are connected in parallel in the refrigerant circuit. When using a single compressor, almost the same refrigerant pressure and therefore almost the same refrigerant temperature is established on the evaporator for the cabin air as on the chiller. However, this is not desirable in accordance with the aforementioned targets for the temperatures on the chiller and on the evaporator. In order to be able to regulate the refrigerant output on the chiller, an electrically switchable expansion valve was previously provided, via which a refrigerant mass flow via the chiller and thus the desired refrigerant temperature is set.

However, it is disadvantageous here that the clocking of the refrigerant circuit, in particular in certain operating states, leads to vibrations in the refrigerant circuit, which is reflected in poor control quality or also in acoustic problems. Furthermore, an electrical actuator must be designed for a comparatively high number of cycles (clocking) in order to guarantee the durability of the expansion valve over the service life. This is particularly reflected in an increased amount of copper and steel and thus the higher costs and weight.

The present invention therefore deals with the problem of specifying an improved or at least an alternative embodiment for a temperature control system of a motor vehicle, which in particular overcomes the disadvantages known from the prior art.

This problem is solved according to the invention by the subject matter of independent claim 1. Advantageous embodiments are the subject of the dependent claims.

The present invention is based on the general idea of providing a coolant bypass line on the chiller and a valve device for controlling the coolant flow flowing in the coolant bypass line instead of an electrically switchable (clockable) expansion valve, and thereby the performance of the chiller without the previously required, structurally complex and expensive electrically switchable expansion valve to control or regulate. Of course, a throttle / expansion device is still required for the evaporation of the refrigerant in the chiller, whereby a simple TXV (thermostatic expansion valve) or a fixed throttle (fix orifice - unchangeable cross-section) is sufficient, and just no more electrically switchable (tactile) expansion valve is required. The temperature control system according to the invention for a motor vehicle has, in a known manner, a cooling circuit in which a coolant flows, and a refrigerant circuit in which a coolant flows. A coolant cooler, a chiller, at least one component to be temperature-controlled and a first coolant pump are arranged in the coolant circuit, with a condenser, the chiller, an evaporator and a compressor for compressing the coolant being arranged in the coolant circuit. The condenser can be in heat-transferring contact with the coolant cooler. A “heat-transferring contact” means, for example, a series connection of the condenser and the coolant cooler, so that an air stream flows through them one after the other. This enables heat transfer through the air flow, which, depending on the direction of flow, absorbs heat in the condenser and passes it on to the coolant cooler, or vice versa. A “heat transfer contact” does not mean a direct connection or physical contact between the condenser and the coolant cooler or a fluid connection between the refrigerant and the coolant. According to the invention, the first coolant bypass line bypassing the chiller is now provided, in which a first valve device is arranged which controls or regulates a coolant flow flowing through the chiller as a function of a coolant temperature on the chiller outlet side. This makes it possible to dispense with an electrically switchable expansion valve that was previously required, as a result of which not only this comparatively expensive component is eliminated, but also a corresponding cabling and control effort for the same. Overall, the temperature control system according to the invention can be used to achieve a structurally comparatively simple control or regulation of the target temperature on the chiller, which is also inexpensive.

In an advantageous development of the solution according to the invention, the first valve device is designed as a thermostatic valve or as an electrically controllable valve. In particular, the design variant as a thermostatic valve offers the great advantage that this enables a structurally simple self-regulation of the target temperature on the chiller, such a thermostatic valve having, for example, a wax expansion element, via which the valve device can be switched or adjusted and thereby by the chiller or first coolant bypass line flowing coolant flow are adjustable. Of course, an alternative embodiment with an electrically controllable valve is also conceivable, in which case a temperature sensor must additionally be provided, which detects the coolant temperature on the chiller outlet side and forwards it to a control device or an actuating device which controls the first valve device as a function of the coolant temperature detected on the chiller outlet side. The second variant offers the great advantage that the first valve device can also be placed upstream of the chiller in the coolant circuit or at any desired, in particular structurally advantageous, location in the first coolant bypass line.

In an advantageous development of the solution according to the invention, the first valve device is arranged downstream of the chiller in the coolant circuit. Here, in particular, the use of a thermostatic valve for the first valve device lends itself, since such a thermostatic valve, which projects into the coolant circuit with its wax expansion element, enables a comparatively simple and inexpensive control of the valve device and thus the coolant flows flowing through the chiller and through the first coolant bypass line is possible.

As an alternative to this, it is also conceivable that the first valve device is arranged upstream of the chiller in the coolant circuit or in the first coolant bypass line, in which case a temperature sensor is provided which detects the coolant temperature on the chiller outlet side. The first valve device is then controlled or regulated as a function of the coolant temperature on the chiller outlet side via a corresponding actuating device. In this case, the first valve device is designed as an electrically switchable or controllable valve. Of course, it is conceivable that the first valve device not only has two extreme switching positions, but also any intermediate positions that enable the coolant flows through the first coolant bypass line and the chiller to be divided as desired.

In a further advantageous embodiment of the solution according to the invention, the at least one component to be temperature-controlled is a vehicle battery and / or electronics. Such a vehicle battery can, for example, be part of an electric vehicle, the cooling of such a vehicle battery being decisive for the performance of the latter, since it develops its optimum performance in a predefined temperature window. Electronics can also be cooled via the coolant circuit and thus kept in a temperature window that ensures functionality.

In a further advantageous embodiment of the solution according to the invention, a heating device is provided in the coolant circuit downstream of the chiller. Such a heating device makes it possible, for example at cold outside temperatures, to heat the coolant flowing in the coolant circuit and thereby to heat the at least one component to be cooled or tempered. Particularly at very low outside temperatures, the performance of vehicle batteries drops sharply, so that heating is advantageous for their optimal performance. In addition, a second coolant bypass line that bypasses the heating device can be provided, in which a second valve device is arranged. If heating of the coolant is therefore not necessary, the heating device is switched off and the coolant does not flow in the coolant circuit through the heating device but exclusively through the second coolant bypass line, as a result of which a flow resistance and thereby the performance of a coolant pump can be reduced.

In a further advantageous embodiment of the solution according to the invention, the first coolant bypass line and the first valve device are at least partially integrated in the chiller and, together with it, form a prefabricated assembly. This offers the great advantage that a particularly compact design can be achieved and, in addition, a prefabricated assembly that facilitates subsequent assembly, for example in an electric vehicle.

The present invention is further based on the general idea of equipping an electric vehicle with a vehicle cabin and a temperature control system described above and thereby transferring the advantages described above to such an electric vehicle. In particular, the electric vehicle according to the invention can thereby be manufactured more cost-effectively and in a structurally significantly less complex manner.

Further important features and advantages of the invention emerge from the subclaims, from the drawings and from the associated description of the figures with reference to the drawings.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own without departing from the scope of the present invention.

Preferred exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the following description, the same reference symbols referring to the same or similar or functionally identical components.

• 1 ein erfindungsgemäßes Temperierungssystem für ein Kraftfahrzeug,
• 2 eine Detaildarstellung A aus 1,
• 3 eine Darstellung wie in 2, jedoch mit einer elektrisch steuerbaren ersten Ventileinrichtung,
• 4 eine Darstellung wie in 2, jedoch mit einer weiteren Kühlmittelpumpe in der ersten Kühlmittelbypassleitung,
• 5 ein erfindungsgemäßes Temperierungssystem mit einer in der ersten Kühlmittelbypassleitung angeordneten ersten Ventileinrichtung und einem Temperatursensor,
• 6 eine Darstellung wie in 3, jedoch mit einer stromauf des Chillers angeordneten ersten Ventileinrichtung.

Here, each schematically,

• 1 an inventive temperature control system for a motor vehicle,
• 2nd a detailed representation A out 1 ,
• 3rd a representation like in 2nd , but with an electrically controllable first valve device,
• 4th a representation like in 2nd , but with another coolant pump in the first coolant bypass line,
• 5 a temperature control system according to the invention with a first valve device arranged in the first coolant bypass line and a temperature sensor,
• 6 a representation like in 3rd , but with a first valve device arranged upstream of the chiller.

According to the 1 has a temperature control system according to the invention 1 for a motor vehicle 2nd a coolant circuit 3rd on in which a coolant 4th flows, as well as a refrigerant circuit 5 in which a refrigerant 6 flows. In the coolant circuit 3rd are a coolant cooler 7 , a chiller 8th , at least one component to be tempered / cooled 9 and a first coolant pump 10 arranged. In the refrigerant circuit 5 are a capacitor 11 , the chiller 8th , an evaporator 12th and a compressor 13 for compressing the refrigerant 6 arranged. The chiller 8th is thus both in the refrigerant cycle 5 as well as in the coolant circuit 3rd heat transfer between these two circuits 3rd , 5 involved. The condenser 11 and the coolant cooler 7 can be in heat transfer contact, so that cooling of the refrigerant 6 in the capacitor 11 through the coolant cooler 7 is possible. With a “heat-transferring contact” there is, for example, a series connection of the capacitor 11 and the coolant cooler 7 meant that these are flowed through by an air stream one after the other. This enables heat to be transferred through the air flow depending on the direction of flow in the condenser 11 Absorbs heat and this to the coolant cooler 7 continues, or vice versa. With a "heat transfer contact" there is no direct connection or physical contact between the condenser 11 and the coolant cooler 7 or a fluidic connection between refrigerant 6 and coolant 4th meant. According to the invention, one is now the chiller 8th immediate first coolant bypass line 14 (see also the 2nd to 6 ) provided in which a first valve device 15 is arranged, one by the chiller 8th and the first coolant bypass line 14 controls the flowing coolant flow depending on a chiller outlet-side coolant temperature. This makes control of the target temperature of the chiller particularly simple 8th to 25 to 35 ° C, for example, which is the target temperature for the components to be tempered 9 comes into consideration while on the refrigerant circuit side evaporator 12th A target temperature of 2 to 10 ° C or up to a maximum of 12 ° C is easily adjustable. The evaporator 12th serves to temper the cabin air 26 of the motor vehicle 2nd , especially cabin air 26 of an electric vehicle. It goes without saying for the evaporation of the refrigerant 6 in the chiller 8th A throttle / expansion device is still required, but now a simple TXV (thermostatic expansion valve) or a fixed throttle (fix orifice - invariable cross-section) is sufficient and an electrically switchable (tactile) expansion valve is no longer required.

Consider the embodiments of the first valve device 15 according to the 1 , 2nd and 4th , there is the first valve device 15 designed as a thermostatic valve and at a junction point of the first coolant bypass line 14 into the coolant circuit 3rd positioned, whereby the use of a simple wax expansion element for detecting the coolant temperature on the chiller outlet side and thus for adjusting the first valve device 15 is possible. The thermostatic valve as the first valve device 15 is, for example, to the desired target temperature 25th designed up to 35 ° C and opens the cross section of the first coolant bypass channel 14 until there is a mixed temperature of the coolant on the chiller outlet side 4th to the desired target temperature of 25 to 30 ° C. The great advantage of a first valve device designed as a thermostatic valve 15 is, in particular, that it can be manufactured inexpensively and for the entire service life of the temperature control system 1 can be interpreted.

Alternatively, it is also conceivable to use an electrically controllable valve E as the first valve device 15 use, as is the case, for example, in accordance with the 3rd and 5 and 6 is shown. In this case there is also a temperature sensor T to record the chiller outlet side Coolant temperature required, as well as an actuator 16 that the first valve device 15 depending on the temperature sensor T determined coolant temperature controls or regulates. Such a temperature sensor T naturally also has a first valve device designed as a thermostatic valve 15 on (cf. the 1 and 2nd ), in which case the temperature sensor T for example, a wax expansion element, which also functions as an actuating device. An electrically controllable valve E as the first valve device 15 of course requires cabling, not shown, to open or close it.

If you look at that 1 further, you can see that the chiller 8th and the evaporator 12th in the refrigerant circuit 5 are connected in parallel. You can also see that in the refrigerant circuit 5 additionally a memory 17th for storing energy and / or refrigerant 6 is provided.

Now consider the individual embodiments of the temperature control system according to the invention 1 , you can according to the 1 and 2nd recognize that there is the first valve device 15 at the end of the first coolant bypass line 14 , that is to say more precisely at an entry point into the coolant circuit 3rd is arranged. This also applies to the embodiments according to the 3rd and 4th . In the embodiment according to the 5 is the first valve device 15 in the first coolant bypass line 14 arranged and over the actuator 16 with that at the confluence point 18th arranged temperature sensor T connected. According to the 6 is the first valve device 15 at the beginning of the first coolant bypass line 14 arranged at a junction 19th on which the first coolant bypass line 14 from the coolant circuit 3rd branches. In this case too, there is a temperature sensor T provided at the confluence point 18th is arranged and via the actuator 16 with the first valve device 15 is connected so that it can be controlled or regulated depending on the chiller outlet-side coolant temperature.

Consider the first coolant pump 10 , you can see that these are in accordance with the 1 upstream of the coolant cooler 7 is arranged, which alternatively also in the first coolant bypass line 14 can be arranged. In theory, it is also conceivable that in the first coolant bypass line 14 another coolant pump 20 is arranged. In the 4th are both reference numerals 10 and 20 drawn for the coolant pump, whereby it is of course clear that it is in the 4th drawn coolant pump to either the first coolant pump 10 or another coolant pump 20 acts.

The components to be tempered 9 can, for example, a vehicle battery 21st or electronics 22 be so with the coolant circuit 3rd different components 9 can be tempered, in particular cooled.

Furthermore, one can be provided in the coolant circuit 3rd downstream of the chiller 8th arranged heating device 23 (see. 1 ), which is the coolant, especially at very low outside temperatures 4th in the coolant circuit 3rd heat and thus the component to be tempered 9 can heat. To achieve a flow resistance in the coolant circuit 3rd To keep it as low as possible is one of the heating devices 23 immediate second coolant bypass line 24th provided, in which a second valve device 25th is arranged.

Thus, for example, there is no heating of the components to be tempered 9 required or desired, the entire coolant flow flows through the second coolant bypass line 24th and not by the heater 23 whereby the flow resistance and thus also that for the coolant pump 10 required power can be kept low.

In a further advantageous embodiment of the solution according to the invention, the first coolant bypass line 14 and the first valve device 15 at least partially in the chiller 8th integrates and forms together with this a prefabricated or prefabricated assembly, whereby not only a compact design but also simplified logistics and assembly can be achieved.

In general, with the temperature control system according to the invention 1 a previously required electrically switchable (clockable) expansion valve and an associated and also necessary complex circuit are dispensed with, which results in different target temperatures on the evaporator 12th , for example for cooling cabin air 26 of the motor vehicle 2nd , which can be designed as an electric vehicle, for example, and the chiller 8th can be achieved. Especially the variant in which the first valve device 15 is designed as a thermostatic valve, represents a structurally extremely simple, long-lasting and cost-effective embodiment. By eliminating an actuator that was previously required for the electrically switchable expansion valve, the number of components and the associated storage and logistics expenditure and a weight can also be reduced.

Claims (11)

Temperature control system (1) for a motor vehicle (2), - with a coolant circuit (3), in which a coolant (4) flows, - with a coolant circuit (5), in which a coolant (6) flows, - wherein in the coolant circuit ( 3) a coolant cooler (7), a chiller (8), at least one component (9) to be temperature-controlled and a first coolant pump (10) are arranged, - a condenser (11), the chiller (8) in the refrigerant circuit (5) , An evaporator (12) and a compressor (13) for compressing the refrigerant (6) are arranged, characterized in that a first coolant bypass line (14) which bypasses the chiller (8) is provided and in which a first valve device (15) is arranged which controls or regulates a coolant flow flowing through the chiller (8) and the first coolant bypass line (14) as a function of a coolant temperature on the chiller outlet side. Tempering system after Claim 1 , characterized in that the first valve device (15) is designed as a thermostatic valve or as an electrically controllable valve (E). Tempering system after Claim 1 or 2nd , characterized in that the first valve device (15) is arranged downstream of the chiller (8) in the coolant circuit (3). Tempering system after Claim 1 or 2nd , characterized in that - the first valve device (15) is arranged upstream of the chiller (8) in the coolant circuit (3) or in the first coolant bypass line (14), - that a temperature sensor (T) is provided which detects a coolant temperature on the chiller outlet side, - That an actuating device (16) is provided which controls or regulates the first valve device (15) as a function of the coolant temperature on the chiller outlet side. Temperature control system according to one of the Claims 1 to 4th , characterized in that - the first coolant pump (10) is arranged in the first coolant bypass line (14) or upstream of the coolant cooler (7), or - that a further coolant pump (20) is arranged in the first coolant bypass line (14). Temperature control system according to one of the preceding claims, characterized in that the at least one component (9) to be temperature-controlled is a vehicle battery (21) and / or electronics (22). Temperature control system according to one of the preceding claims, characterized in that a heating device (23) is provided in the coolant circuit (3) downstream of the chiller (8). Tempering system after Claim 7 , characterized in that a second coolant bypass line (24) which bypasses the heating device (23) is provided, in which a second valve device (25) is arranged. Temperature control system according to one of the preceding claims, characterized in that the evaporator (12) and the chiller (8) are connected in parallel in the refrigerant circuit (5). Temperature control system according to one of the preceding claims, characterized in that the first coolant bypass line (14) and the first valve device (15) are at least partially integrated in the chiller (8) and together with this form a prefabricated assembly. Electric vehicle with a vehicle cabin (26) and a temperature control system (1) according to one of the preceding claims.

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