US20120304674A1

US20120304674A1 - Climate control system for a vehicle and method for controlling temperature

Info

Publication number: US20120304674A1
Application number: US13/519,762
Authority: US
Inventors: Otfried Schwarzkopf
Original assignee: Voss Automotive GmbH
Current assignee: Voss Automotive GmbH
Priority date: 2009-12-30
Filing date: 2010-12-11
Publication date: 2012-12-06
Also published as: EP2519415B1; WO2011079904A1; EP2519415A1; CN102781693B; DE102009060860B4; CN102781693A; DE102009060860A1

Abstract

In a climate control system for a vehicle having at least one refrigerant circuit, at least one temperature control circuit for controlling the temperature of a vehicle interior, and at least one vehicle component, in particular of an electric vehicle or hybrid vehicle, at least one device for absorbing heat from the temperature control circuit and at least one device for releasing heat to the temperature control circuit are provided. In a method for controlling the temperature of vehicle components using at least one refrigerant circuit and at least one temperature control circuit, heat is absorbed from the temperature control circuit into the refrigerant circuit on the low-pressure side of the refrigerant circuit, and heat is released to the temperature control circuit by the refrigerant circuit on the high-pressure side of the refrigerant circuit.

Description

FIELD OF THE INVENTION

The invention relates to a climate control system for a vehicle comprising at least one refrigerant circuit and at least one temperature control circuit for controlling the temperature of a vehicle interior and at least one vehicle component, in particular an electric vehicle or hybrid vehicle, a method for controlling the temperature of vehicle components using at least one refrigerant circuit and at least one temperature control circuit as well as a vehicle having such a climate control system.

BACKGROUND OF THE INVENTION

Climate control systems for vehicles, and methods for controlling the climate of vehicle interiors are known. For example, EP 0 991 536 B1 discloses an air conditioning system and a method for heating a refrigerant of a drive unit. The vehicle air-conditioning system in this case comprises refrigerant circuit consisting of at least one condenser, an expansion member, an evaporator, a compressor, and a bypass line bridging the condenser, as well a bypass valve for opening and closing the bypass line, where a heat exchanger is disposed in the refrigerant circuit, which can be acted upon by a refrigerant on one side and on the other side by a coolant of the drive unit. The heat exchanger in the refrigerant circuit is disposed between the compressor and the condenser. For heating the coolant of the drive unit, the refrigerant is brought to a higher pressure via the heat exchanger by compressing the refrigerant in the compressor with the result that said refrigerant is heated, so that heat is produced and is transferred from the refrigerant to the coolant, for more rapid heating of the drive unit. During the heating-up phase of the coolant, the condenser is bridged and heat generated in the compressor is either transferred exclusively in the heat exchanger to the coolant or through the evaporator to the air flowing through the evaporator.
Known from DE 102 07 128 A1 is a vehicle air conditioning system, in particular a CO₂air conditioning system, whose refrigerant circuit comprises a compressor, a refrigerant cooler, an inner heat exchanger between coolant cooler and evaporator side, an expansion valve, and an evaporator, where for switching the air-conditioning system from cooling mode into heating mode, an auxiliary heat exchanger corresponding with an engine-side cooling circuit is integrated between compressor and refrigerant cooler. Located downstream of the auxiliary heat exchanger is an expansion valve by which means the refrigerant can be throttled to a lower pressure in the heating mode. The auxiliary expansion valve is part of a bypass line which branches from the refrigerant line between auxiliary heat exchanger and refrigerant cooler. This is connected parallel to the refrigerant line while bridging a check valve disposed in this line.
Known from DE 44 089 60 C1 is an apparatus for cooling a traction battery, in particular for an electric vehicle. Here a battery cooling circuit is provided which comprises an air-cooled heat exchanger and a battery-operated circulation pump. Furthermore, a cooling system is provided comprising a battery-operated compressor, a condenser, an expansion valve and an evaporator, which is inserted into the battery cooling circuit in series with a battery serpentine cooling coil section and the air-cooled heat exchanger, in thermal contact with the latter. A bypass line is provided in the battery cooling circuit to bypass the air-cooled heat exchanger, a switching valve being located upstream thereof.
Battery systems for hybrid, electric vehicles and vehicles with fuel cell drive and battery specifically bring with them the requirement to provide temperature control of the battery, i.e. heating and cooling of the battery independently of any engine waste heat produced since in electric vehicles such engine waste heat such as accumulates in vehicles with internal combustion engines no longer occurs. In hybrid vehicles the engine heat can possibly be used for heating the battery. In principle, in the said types of vehicles no engine heat is available for heating a passenger compartment.
The most commonly used energy storage device at the present time is a nickel metal hydride battery (NiNH battery). Furthermore, the provision of sodium nickel chloride batteries (NaNiCl batteries) is known in the so-called smarted area. These batteries have a high energy density of 90 to 140 Wh/kg, at high operating temperature however. Heating is therefore required to maintain the operational readiness of these batteries when the vehicle is stationary. Lithium on batteries at the present time have the highest energy density of all the available rechargeable energy storage devices. Compared with conventional nickel metal hydride batteries, lithium ion high-voltage batteries have a higher energy density and a better electrical efficiency with at the same time compact dimensions and a low weight. The specific energy density here for example can be 120 to 150 Wh/kg. Cooling and heating these batteries is therefore particularly important to maintain the operational readiness.
With the known vehicle air-conditioning systems described previously or the apparatus for cooling a traction battery, it is not possible to ensure operational readiness in particular of batteries having a high energy density since it, is not possible with any of the systems both to cool and heat these batteries and at the same time control the temperature of the vehicle interior where all the functions are available independently of one another.

SUMMARY OF THE INVENTION

It is therefore the object of the present invention to provide a climate control system and a method for controlling the temperature of components of a vehicle in which temperature control of individual components of the vehicle such as batteries, fuel cells, power electronics, DC/DC converters for example for fuel cells, fluid systems etc. and of a vehicle interior, which is desired or required in each case during operation, can be achieved independently of one another by providing a single system.
The object is solved for a climate control system for a vehicle comprising at least one refrigerant circuit and at least one temperature control circuit for controlling the temperature of a vehicle interior and at least one vehicle component, in particular an electric vehicle or hybrid vehicle whereby at least one device for absorbing heat from the temperature control circuit and at least one device for releasing heat to the temperature control circuit are provided. For a method for controlling the temperature of vehicle components using at least one refrigerant circuit and at least one temperature control circuit, the object is solved whereby heat from the temperature control circuit on the low-pressure side of the refrigerant circuit is absorbed into this and heat is released to the temperature control circuit on the high-pressure side of the refrigerant circuit by said refrigerant circuit. Further developments of the invention are defined in the dependent claims.
By this means a climate control system, in particular for a vehicle, is provided in which at least one refrigerant circuit and at least one temperature control circuit are coupled to one another such that both heating and cooling of vehicle components such as batteries, fuel cells, power electronics, fluid systems etc. and a vehicle interior can be achieved as required with one and the same system. The entire temperature control, i.e. heating and cooling, of the vehicle components is accomplished by means of the heat transfer medium circuit in the form of the temperature control circuit connected to the components to be temperature controlled. Components which are to be temperature controlled by means of the climate control system individually or in any combination with one another are, in addition to batteries as well as an internal combustion engine, for example, electric motors, converters, the power electronics of the vehicle, electrically operated auxiliary units and fuel cells. When at least two components are combined with one another, a series or parallel connection of the components can be provided. Also any arbitrary fluid system can be temperature controlled by means of the climate control system.
Consequently, unlike the prior art of EP 0 991 536 B1 with the climate control system according to the present invention it is not only possible to supply heat to the drive unit and also not only an air-conditioning system with a facility for switching from cooling to heating mode is provided, as described in DE 102 07 128 A1 but a skillful at least double intermeshing of refrigerant circuit and temperature control circuit so that a heat can be supplied and released to and from the temperature control circuit from and to the refrigerant circuit by this means. The vehicle components can thus be cooled and also heated alternately during operation in order to enable an optimal adaptation to the particular external requirements and ensure the operational readiness of the vehicle components. The vehicle components can thereby be held at an optimal temperature independently of external weather influences. At the same time optimal climate control of the vehicle interior can be achieved.
In order to be able make a particularly simple adaptation to the operating state of the vehicle components required in each case and the vehicle interior, it is advantageous to provide at least one device for connecting and disconnecting at least one component and/or a subcircuit or circuit of the climate control system, in particular at least one bridging valve and/or multiway valve and/or bypass line. The individual elements or components of the refrigerant circuit which can be accessed by the temperature control circuit for heat exchange as well as individual components of the two circuits itself can thus be connected or disconnected, or bridged according to the respectively desired operating state of heating and/or cooling of the vehicle components and the vehicle interior.
It is advantageous if the device for absorbing heat from the temperature control circuit is a low-pressure side heat exchanger, in particular an evaporator, and/or the device for releasing heat to the temperature control circuit is a high-pressure side heat exchanger of the at least one refrigerant circuit, in particular a desuperheater or condenser. Refrigerant circuit, which for example is part of a vehicle air-conditioning system which can run in the so-called air-conditioning or refrigerating system and heat pump mode, and temperature control circuit can be intermeshed so that heat can advantageously be released from the temperature control circuit to the refrigerant circuit via an evaporator. The temperature control circuit can further comprise a cooler which is connected to the ambient air and a heating heat exchanger which is connected to the vehicle interior. A unit comprising the heating heat exchanger of the temperature control circuit and an evaporator of the refrigerant circuit can be provided. By this means both heating and cooling of the vehicle interior is possible. The refrigerant circuit advantageously further comprises two refrigerant coolers or desuperheaters, where the first refrigerant cooler or desuperheater is further advantageously disposed downstream of a compressor in the flow direction so that it can be used for transfer of heat to the temperature control circuit on the high-pressure side. The second refrigerant cooler can act as an evaporator (in the heat pump mode) or as a condenser or liquefier or refrigerant desuperheater. Said cooler is disposed in the flow direction downstream of the first refrigerant cooler and upstream of the first evaporator in communication with the temperature control circuit or an expansion valve disposed between this and the second refrigerant cooler.
A unit comprising the cooler of the temperature control circuit and the second refrigerant cooler can further advantageously be provided, where this unit is temperature controlled by the ambient air, i.e. cooled or heated, for example, in relation to the heat pump.
An inner heat exchanger integrated in the refrigerant circuit can further advantageously be provided. This is disposed in the flow direction downstream of the second refrigerant cooler and downstream of a second evaporator so that internal heat exchange can take place between the forward and backward flowing refrigerant or between the high-pressure side and the low-pressure side. The two evaporators can be connected in series or operated in parallel, where the last variant is usually preferred. In order to be able to provide applications in which the inner heat exchanger is bridged as in the heat pump mode, a bridging or bypass valve is advantageously disposed in the flow direction downstream of the second refrigerant cooler. When bridging the inner heat exchanger, refrigerant can be fed back from the second refrigerant cooler directly to the compressor. Heat is absorbed at the second refrigerant cooler and heat is released at the first refrigerant cooler. The refrigerant is expanded downstream of the first refrigerant cooler and the second refrigerant cooler is then disposed on the low-pressure side. Heating of the vehicle components and the vehicle interior can be achieved with such a structure.
A bridging valve and/or a bypass line is further advantageously provided for bridging the expansion valve in the flow direction downstream of the first refrigerant cooler. In particular, when cooling components of the vehicle and at the same time heating a vehicle interior, by bridging the expansion valve refrigerant can flow directly via the bridging valve from the first refrigerant cooler to the second refrigerant cooler at high pressure. The second refrigerant cooler then acts as a condenser and brings about a release of heat and liquefaction of the refrigerant. For this operating state of cooling the vehicle components and at the same time heating the vehicle interior, a pressure reduction advantageously only takes place downstream of the second refrigerant cooler upstream of the first evaporator via the second expansion valve advantageously provided there.
A parallel circuit of two evaporators can be provided in the refrigerant circuit. This proves to be particularly advantageous in order to be able to operate both refrigerant circuits independently of one another. In this case, two expansion valves are advantageously disposed between the second refrigerant cooler and the particular evaporator, where the refrigerant flow downstream of the second refrigerant cooler can be divided accordingly into two mass flows depending on how the air-conditioning system is operated. If a more cost-effective solution is to be selected here, a series circuit of two evaporators of the at least one refrigerant circuit can be provided. In the latter solution the division of the mass flow and the expansion valve upstream of the second evaporator can be omitted. The provision of two expansion valves makes it possible to expand to different pressures on the low-pressure side.
Advantageously only one temperature control circuit is provided for cooling and for heating vehicle components such as, for example, the battery, fuel cells etc. Bridging valves and bypass lines are thereby provided for selectively connecting and disconnecting individual elements of the temperature control circuit and the refrigerant circuit and for selectively connecting and disconnecting components to be temperature-controlled.
The temperature control circuit for controlling the temperature of vehicle components can further advantageously comprise a cooling circuit and a heating circuit which then each individually access the device for absorbing heat from the temperature control circuit and the device for releasing heat to the temperature control circuit.
Furthermore, the temperature control circuit can comprise two cooling circuits for operating components of a vehicle, in particular a hybrid vehicle, at different temperature levels. Such different temperature levels are primarily requested in a hybrid vehicle since an internal combustion engine operates at a different temperature level, i.e. usually cooling to about 90° C. compared with the other vehicle components such as battery, fuel cell power electronics, fluid systems etc.
It is also possible to divide individual components of the climate control system, air-conditioning or refrigeration system or heat pump into two or possibly more circuits.
It is also found to be further advantageous if the one or more pumps and one or more compressors of the circuits and subcircuits can be operated electrically or are provided to be driven since these can thus be operated very efficiently with low energy supply and are particularly suitable for electric vehicles.
A refrigerant that can be used in the refrigerant circuit is advantageously selected from CO₂or R744, a hydrofluoro olefin such as HFO-1234yf, a tetrafluoroethane such as 1,1,1,2-tetrafluoroethane or R134a. CO₂is a high-pressure refrigerant that operates in the supercritical range whereas HFO-1234yf and R134 are refrigerants which operate in the subcritical range. Cooling water with added antifreeze, for example, is suitable for the temperature control circuit.
In principle, a direct cooling of components, particularly of a battery, could even be accomplished, by the refrigerant circuit bypassing the heat transfer medium or temperature control circuit. In this case, however additional measures must be taken to adapt or to compensate for the different pressure prevailing in the refrigerant circuit and the components.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed explanation of the invention, exemplary embodiments of this are described in detail in the following with reference to the drawings. In these:

FIG. 1 shows an overall view of a first embodiment of a climate control system according to the invention,

FIG. 2 shows the overall view of the climate control system according to FIG. 1 for the operating state of heating a battery and heating a vehicle interior,

FIG. 3 shows the overall view of the climate control system according to FIG. 1 for the operating state of cooling the battery and heating the vehicle interior,

FIG. 4 shows the overall view of the climate control system according to FIG. 1 for the operating state of cooling the battery and heating the vehicle interior,

FIG. 5 shows the overall view of the climate control system according to FIG. 1 for the operating state of cooling the battery and cooling the vehicle interior,

FIG. 6 shows an overall view of a second embodiment of a climate control system according to the invention with two separate heating and cooling circuits,

FIG. 7 shows an overall view of a third embodiment of a climate control system according to the invention for a hybrid vehicle with two cooling circuits and one heating circuit and

FIG. 8 shows an overall view of another embodiment of a climate control system according to the invention for a hybrid vehicle with a series connection of two evaporators of the refrigerant circuit.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic diagram of a climate control system 1 comprising a refrigerant circuit 2 and a temperature control circuit 3. The refrigerant circuit can for example, be part of a vehicle air-conditioning system FK, which can be operated in air-conditioning and heat pump mode. The refrigerant circuit 2 comprises a compressor 20, a first refrigerant cooler 21, a first expansion valve 22, a second refrigerant cooler 23, which can be operated as condenser or evaporator (in heat pump mode) according to the mode. A bypass line with a bridging valve 24 is disposed parallel to the expansion valve 22. The refrigerant circuit 2 further comprises an inner heat exchanger 25 downstream of the second refrigerant cooler 23 in the flow direction of the refrigerant. This is only optionally provided and when provided, as shown in FIG. 1, this can be bridged by means of a bridging valve 26, whereby refrigerant can flow back from the second refrigerant cooler 23 to the compressor 20 via a line 51. The second refrigerant cooler 23 is operated in heat pump mode as an evaporator, whereby the refrigerant is heated.
Downstream of the inner heat exchanger 25, the refrigerant line system branches into two lines via a three-way valve 27. Instead of the three-way valve, another type of valve or a different line guidance can also be provided here. Both lines 28, 29 each comprise an expansion valve. These two expansion valves 40, 41 lead to two evaporators, the first evaporator 42, which is in communication with the temperature control circuit 3, and the second evaporator 43, which can be used for temperature control of the vehicle interior 4. The second evaporator 43 together with a heating heat exchanger 30 of the temperature control circuit 3 forms a heating/cooling unit 31 for temperature control of the vehicle interior 4. The heating/cooling unit 31 further comprises a fan or a blower 32.
Another three-way valve 44 is provided to return the refrigerant emerging downstream of the evaporator 43 to the compressor 20. The line 45 leading away from this valve leads to the inner heat exchanger 25. The other line 46 going away from the three-way valve 44 is connected to the first evaporator 42. The refrigeration circuit is thus closed by this means.
In addition to the heating heat exchanger 30 already mentioned, the temperature control circuit 3 also comprises a bridging valve 33 for this. The temperature control circuit 3 further comprises a cooler 34 with fan or blower 35, which is in communication with the surroundings 5 or ambient air. The cooler 34 and the second refrigerant cooler 23 can also be operated as a unit for absorbing and releasing heat from or by the surroundings 5.
The first evaporator 42 of the refrigerant circuit 2, by which means heat exchange can take place with the temperature control circuit 3, can be bridged by means of a bridging valve 36 located downstream of the cooler 34 from the coolant flow. A three-way valve not shown in FIG. 1 or another type of valve can be provided in the branches of the line 64 going from the cooler 34 to the bridging valve 36 or to the evaporator 42.
Heat exchange of the refrigerant circuit with the temperature control circuit can take place via the first refrigerant cooler 21. A corresponding line 37 is provided here from the temperature control circuit to the first refrigerant cooler 21 and back to the temperature control circuit. However, a bridging of the first refrigerant cooler on the part of the temperature control circuit by means of a bridging valve 38 is also possible. Consequently, heat exchange with the first refrigerant cooler 21 need not take place in each case. Various operating states for this are explained in detail hereinafter.
The particular component of the climate control system performing the heat transfer can be operated in direct flow, counterflow, or cross flow. Other operating modes are also possible depending on the heat transfer medium or heat exchanger.
FIG. 1 further shows as an example a battery 6 as a component of a vehicle to be temperature controlled, which is inserted in the temperature control circuit 3. Alternatively or additionally, other components 600, 601 of a vehicle such as, for example, the power electronics of the vehicle, fluid systems, fuel cells etc. can be temperature-controlled via the climate control system 1. These individual components can be connected in parallel or in series, i.e. inserted in the climate control system. Other heat exchangers can also be connected here. These can for example, control the temperature of another fluid for refrigeration and/or heat transfer. In order to enable such connection to and removal from the climate control system, bridging valves are provided here in each case. For example, a bridging valve 39 for bridging the battery 6 is provided downstream of the budging valve 38 in the flow direction of the coolant. The coolant can thus either flow past the battery 6 or be used for controlling the temperature thereof. Instead of bridging valves, other types of valves can also be used here such as, for example, directional valves.
Most batteries, in particular of electric vehicles or fuel cell vehicles require temperatures of 15-35° C. for safe operation. If these temperatures are not present as a result of ambient temperatures which can fluctuate, for example, between −20° C. and +40° C., temperature control of the battery or the other components of the vehicle, as specified hereinbefore is required. At the same time, depending on the present ambient temperatures, climate control of the vehicle interior is desired at temperatures which generally lie between 16° C. and 25° C. Thus various operating states of battery or other vehicle components and circuits and the vehicle interior can be requested which will be explained in detail hereinafter, with reference to FIGS. 2-8. Possible operating states can be cooling of the battery or components and circuits as well as the vehicle interior, cooling of only the vehicle interior, cooling of only the battery or the other components and circuits of the vehicle, cooling of the battery or other components and circuits of the vehicle in conjunction with heating the vehicle interior, heating both of the battery or components and circuits of the vehicle and also of the vehicle interior, heating only of the vehicle interior and further heating only of the battery or other components and circuits of the vehicle.
FIG. 2 shows the operating state of heating the battery 6 as an example of one or more of the temperature-controllable components and the vehicle interior 4, which comprises heating the vehicle interior and the temperature control circuit. The battery is mentioned hereinafter as a representative for one or more of the components of the vehicle to be temperature controlled. The refrigerant flowing in the refrigerant circuit 2 is hereby compressed by means of the compressor 20 so that the refrigerant is present at point A downstream of the compressor 20 at high pressure and in the superheated state in gaseous form. In this state the refrigerant enters into the refrigerant cooler 21. In this cooler, heat is released via the line 37 to the temperature control circuit 3. The bridging valve 38 is thus closed so that the heat released in the refrigerant cooler 21 configured as a heat exchanger can reach the battery 6 via the lines 60, 61. By this means it is thus possible to heat the battery in the same way as other components of the vehicle.
A further release of heat can be made via the heating heat exchanger 30 to the vehicle interior 4 via the line 62 leading from the battery to the heating heat exchanger. Here the heat not removed in the battery for heating is therefore passed on to the heating heat exchanger 30. If the battery is heated during operation, this heat can be released to the coolant in the line 62 and then arrive at the heating heat exchanger 30. The vehicle interior 4 is heated via the heating heat exchanger 30 in particular with the involvement of the fan 32 or a corresponding blower, which makes heated air flow into the vehicle interior. This air is heated via the heating heat exchanger and blown into the vehicle interior 4 by means of the blower or the fan 32.
The coolant cooled as a result of the release of heat in the heating heat exchanger 30 is passed via the line 63 to the cooler 34. The ambient air of the surroundings 5 can in this case be used to cool the coolant. In particular, battery and vehicle interior are heated whenever the actual value of the temperature is below the predefined desired value of the temperature.
The cooled coolant is passed from the cooler 34 via the line 64 and the closed bridging valve 36 directly to the first refrigerant cooler 21 again in order to be heated again in said cooler. In the example shown, a pump 10 driven by an electric motor is provided for conveying the coolant through the temperature control circuit. It is also possible to provide a circulation which takes place independently, e.g. with evaporating coolant.
In principle, heat is transferred to the temperature control system via the refrigerant cooler 21. This can be accomplished on the one hand when the climate control system is operated as a refrigeration system and on the other hand when it is operated as a heat pump, which will be described hereinafter.
As a result of the release of heat in the refrigerant cooler 21, the refrigerant is present at point B in the line 48 guided from the refrigerant cooler 21 to the expansion valve 22 upstream of the expansion valve 22 at high pressure but at lower temperature that at point A. A pressure reduction takes place via the expansion valve 22 so that the refrigerant is present at point C downstream of the expansion valve at a low pressure. In the line 49 the refrigerant is then present as wet vapor and enters into the second refrigerant cooler 23 as such. The refrigerant cooler 23 here acts as an evaporator so that heat is supplied. The heat required for the evaporation is in particular withdrawn from the ambient air. The second refrigerant cooler 23 and the cooler 34 are in this respect combined as a unit since both can undertake heat exchange with the ambient air 5.
In the line 50 or at point D downstream of the second refrigerant cooler 23, the refrigerant is certainly at low pressure but at increased temperature compared with point C as a result of the absorption of heat. Via the bridging valve 26 which is closed for this purpose, the refrigerant is fed directly back to the compressor 20 via the line 51. Upstream of the compressor at point E the refrigerant is thus at low pressure and has approximately the same temperature as at point D so that subsequently the heating and pressurizing of the refrigerant to high pressure can again be accomplished via the compressor 20, as described hereinbefore.
The first refrigerant cooler 21 can be designed in different ways, according to the most diverse heat exchanger principles. In particular, it can be configured as a counterflow, direct flow or cross flow heat exchanger. The second refrigerant cooler 23 can as already mentioned hereinbefore, be operated both as a liquefier or condenser and also as an evaporator depending on which state (high pressure or low pressure) the refrigerant has on entering the refrigerant cooler 23 and in which form it should be released from the refrigerant cooler 23.
FIG. 3 shows another operating state, i.e. cooling of the vehicle components, here illustrated by the example of the battery 6, and heating of the vehicle interior 4. In the embodiment shown this operating state is accomplished without involvement of the refrigerant circuit 2. Here the coolant only serves for cooling tile battery and heating the vehicle interior. The coolant is cooled by means of the cooler 34 by the ambient air 5 and passes via the line 64, the bridging valve 36 and the bridging valve 38, which are both closed, the line 60, and the line 61 to the battery 6. Here it is used to cool the battery but absorbs the excess heat of the battery according to the heat exchanger principle so that it flows with increased temperature through the line 62 to the heating heat exchanger. Via this heat exchanger the excess heat can be used by heating the air located in the vehicle interior for heating said inner chamber. Consequently, heat is released into the vehicle interior 4 via the heating heat exchanger 30. In the line 63 the coolant is thus returned to the cooler 34 at reduced temperature where the cycle can begin again.
An alternative variant to cooling, for example, of the battery 6 and heating the vehicle interior 4 is shown in the wiring diagram according to FIG. 4. In this embodiment the refrigerant circuit 2 is involved in the heat transfer. The refrigerant gas is compressed by means of the compressor or gas compressor 20 so that, as explained hereinbefore to FIG. 2, it is present in gaseous form at high pressure and superheated at point A downstream of the compressor 20. In this state, the refrigerant enters the refrigerant cooler 21 in which. however, in the present case no heat is released to the temperature control circuit 3 since the refrigerant flows therethrough but not the coolant. On the contrary, the refrigerant passes via the line 48, still at high pressure, to the now closed bridging valve 24. The expansion valve 22 is thus bridged. At point C in the line 49 the refrigerant is still at high pressure and enters into the refrigerant cooler 23 still as superheated gaseous medium. The refrigerant cooler here serves as a liquefier or condenser, where heat is released to the ambient air. An additional release of heat to the low-pressure side of the refrigerant circuit can be accomplished via the inner heat exchanger 25 through which the refrigerant flows subsequently. The refrigerant still at high pressure then passes via the three-way valve 27 and the line 28 to the expansion valve 40, in which a reduction in pressure takes place while the temperature stays the same. At point F downstream of the expansion valve 40, the refrigerant is present at low pressure in the line 52.
From the expansion valve 40 the refrigerant is passed to the evaporator 42, in which heat is absorbed at low pressure. The heat is provided by the coolant in the temperature control circuit 3. For this purpose, the coolant is passed downstream of the cooler 34 via the evaporator 42, where the bridging valve 36 is opened. The coolant cooled accordingly hereby can be pumped via the pump 10, the bridging valve 38, the lines 60 and 61 to the battery in which it is used for cooling thereof.
The refrigerant heated in the evaporator 42 is present at low pressure downstream thereof at point G and is returned via the line 46 and the three-way valve 44 to the inner heat exchanger 25 and from there to the compressor 20. In the inner heat exchanger 25 heat can be exchanged with the refrigerant flowing from the refrigerant cooler 23 to the expansion valve 40. The inner heat exchanger can in principle also be omitted.
From the battery 6 or the other components 600, 601 of the vehicle connected in series or in parallel with this the coolant flows to the heating heat exchanger 30 in order to heat the vehicle interior 4 via said heat exchanger. The correspondingly cooled coolant is then pumped back to the cooler 34 via the line 63.
FIG. 5 shows the climate control system with the respectively active components or elements of the system for the operating state of cooling the battery 6 or components or fluid systems of fuel cells etc. of the vehicle and cooling the vehicle interior 4. In the refrigerant circuit 2 in this case both evaporators 42, 43 and both refrigerant coolers 21, 23 and the optionally provided inner heat exchanger 25 are active. The refrigerant is compressed in the compressor 20 and is thus present in gaseous form at a very high pressure and in a severely superheated state at point A. Via the line 47 the refrigerant then enters into the first refrigerant cooler 21. In this cooler no heat exchange takes place with the temperature control circuit 3 since the coolant does not flow through the refrigerant cooler 21. On the contrary the refrigerant is still passed at high pressure via the bridging valve 24 to the second refrigerant cooler 23. The refrigerant cooler 23 here acts as a liquefier or condenser, where the hot gas can release its heat to the ambient air and condenses. Consequently at point D downstream of the refrigerant cooler 23 the refrigerant is still present at high pressure but at reduced temperature in the largely liquid state. Via the line 50 said refrigerant is fed to the inner heat exchanger 25, in which heat exchange can take place with the back-flowing refrigerant mentioned further below. Two mass flows are formed downstream of the inner heat exchanger 25, which are fed to the expansion valve 40 and to the expansion valve 41 via the three-way valve 27. In both expansion valves the high pressure is reduced to a low pressure with a simultaneous reduction in the temperature of the refrigerant. Via the line 52 the refrigerant is fed to the evaporator 42 and via the line 53 to the evaporator 43. By means of the evaporator 42 an increase in temperature takes place due to absorption of heat from the temperature control circuit, where the bridging valve 36 in the temperature control circuit 3 is closed and the coolant is passed via the evaporator 42 to heat exchange. By this means the coolant is further cooled and passes via the open bridging valve 38 and the lines 60, 61 to the battery 6 or the components of the vehicle to be cooled.
Since no heating of the vehicle interior 4 should take place, the heating heat exchanger 30 is bridged by opening the bridging valve 33 so that the coolant heated in the battery and in the other components of the vehicle is fed directly to the cooler 34 again. In this cooler, the coolant is cooled with the assistance of ambient air.
The refrigerant mass flow supplied via the three-way valve 27 to the expansion valve 41 is passed via the line 53 to the evaporator 43, as already mentioned. Here, the liquid refrigerant evaporates at low pressure and low temperature while absorbing heat from the vehicle interior air, e.g. in circulating air mode or from the external or ambient air, which is supplied to the vehicle interior so that the vehicle interior 4 can be cooled by this means. In principle, cooling is therefore accomplished here via the vehicle air-conditioning system, where the blower or the fan 32 can be switched on or optionally off.
The refrigerant heated in the evaporator 43 is again fed via the three-way valve 44 to the line 45 and via this to the optionally provided inner heat exchanger 25, where heat exchange can take place here with the inflowing refrigerant from the refrigerant cooler 23. The gaseous refrigerant thereby heated further is again fed via the line 51 to the compressor 20 so that the refrigerant can again be compressed here in the compressor 20.
From the evaporator 42 the refrigerant heated by absorption of heat, which has a low pressure at point G, is fed via the line 46 to the three-way valve 44 and via this likewise via the line 45, the inner heat exchanger 25, and the line 51 again to the compressor 20 so that the refrigerant circuit is closed by this means.
As an alternative embodiment, the two evaporators 42, 43 can also be operated at different low-pressure pressure positions. For this purpose a suitable regulating device or at least one check valve is inserted in at least one of the two lines 46, 47 to prevent the refrigerant from flowing back into one of the low-pressure circuits. The optionally provided inner heat exchanger 25 then has a medium low pressure flowing therethrough.
Thus, both battery and also vehicle interior can be cooled by suitable connection or bridging of individual elements of the cooling circuit and the refrigeration circuit. If only the vehicle components 6, 600, 601 or the vehicle interior are to be cooled or heated in each case, the particular part of the circuit is disconnected by opening the bridging valves 33 or 39, that is not supplied with coolant.
FIG. 6 shows a variant of the climate control system 1, in which the refrigerant circuit 2 is provided but not the one temperature control circuit 3 but this as a combination of separate cooling circuit 7 and heating circuit 8. The battery 6 and/or further or other components of a vehicle, which can be connected parallel to or in series with this, as has already been mentioned previously for the embodiment according to FIG. 1, is disposed so that this can be inserted both in the heating circuit 8 and in the cooling circuit 7. For this purpose, as shown in FIG. 6, for example, two three-way valves 70, 71 are disposed upstream and downstream of the battery so that cooling coolant can be supplied via these valves from the cooling circuit 7 in the same way as heated coolant from the heating circuit 8.
In the cooling circuit 7, which comprises the cooler 34 and line 64 leading to the evaporator 42 and the bridging valve 36 for bridging the evaporator 42, a line 72 leads from the evaporator 42 or the bridging valve 36 to the three-way valve 70. From this a line 72 is provided, which goes through the battery and via which heat can be exchanged with regions of the battery or with the battery. Via the second three-way valve 71 and a line 73, the coolant is returned to the cooler 34. In order to provide a movement of the coolant in the cooling circuit, as already provided in the preceding embodiments, a pump 10 a is also provided here, which is preferably driven by an electric motor 11, where other types of pump are fundamentally possible. In the same ways as was explained for the two embodiments according to FIGS. 4 and 5, in the cooling circuit 7 heat can be released via the evaporator 42 to the refrigerant in the refrigerant circuit 2. Likewise, it is naturally also possible to bridge the evaporator 42 by means of the bridging valve 36, as has been explained previously for the two embodiments in FIGS. 2 and 3.
The heating circuit 8 is provided so that it engages in the refrigerant circuit 2 such that heat can be absorbed from the first refrigerant cooler 21 in the refrigeration and in the heat pump mode. The battery can be heated accordingly with this heat from the refrigerant cooler 21.
In addition to a line 80, which leads from a pump 1013 for pumping coolant through the heating circuit 8 to the refrigerant cooler 21, where the pump is again driven by an electric motor 11, the heating circuit 8 comprises a line 81, which leads from the refrigerant cooler 21 to the three-way valve 70.
If the battery or the further components of the vehicle or also fluid systems of the vehicle are not to be heated, a bypass line 82 is provided, which is provided with a bridging valve 83. If the bridging valve 83 is open, the coolant heated by means of the refrigerant cooler 21 flows via the bridging valve 83 and a line 84 to the heating heat exchanger 30. Accordingly, the heating heat exchanger in circulating air mode or in external air mode, as has already been explained previously for FIG. 5, can heat the vehicle interior 4 by heating the air supplied to said heat exchanger. Via another line 85, the coolant can be returned to the pump 10 again and through the line 80 to the refrigerant cooler 21.
If the battery but not the vehicle interior is to be heated, the bridging valve 83 is closed and the three-way valve 70 is opened in the direction of the line 72 a, which leads through the battery, and is closed in the direction of the line 72. In cooling mode the three-way valve is closed in the direction of the line 82 a and opened in the direction of the lines 72 and 72 a. Thus, the battery or the components of the vehicle to be heated or the fluid system of the vehicle to be heated can be heated by means of the heated coolant. The three-way valve 71 downstream of the battery is switched for return of the coolant from the battery back to the pump 10 so that via a further line 86 and a further bridging valve 87, which bridges the heating heat exchanger, the coolant can be returned to the return line 85 and thus to the pump 10 and line 80, accordingly therefore also to the refrigerant cooler 21.
In principle, the refrigerant circuit 2 is constructed according to FIG. 1 and can be operated in a corresponding manner. The evaporator 43 can be used for cooling the vehicle interior, as has already been described for the embodiment of the climate control system according to FIG. 1.
Not only the pumps 10 in the cooling circuit, heating circuit, and temperature control circuit are operated by an electric motor but advantageously also the compressor 20 of the refrigerant circuit 2, particularly in a vehicle driven purely by electric motor. By providing such an electric motor drive for pumps and compressor, a particularly good suitability for hybrid vehicles and electric vehicles is achieved, where merely a comparatively low energy requirement is required for operating the pumps and the compressor.
FIG. 7 shows another embodiment of the climate control system 1, in which two cooling circuits or temperature control circuits are provided, where this structure is particularly suitable for a hybrid vehicle comprising components having different temperature levels. Accordingly, an internal combustion engine 9 is included in the first temperature control circuit 90, which is an engine temperature control circuit. In the engine temperature control circuit 90, a line 91 therefore leads from the cooler 34 to a three-way valve 92 and a further line 93 passes through the internal combustion engine 9 to another three-way valve 94. Another line 95 leads from the three-way valve 94 via a pump 10 a, which is driven by electric motor, via a further line 96 back to the cooler 34. Via the cooler the coolant of the engine temperature control circuit 90 can thus be cooled by means of the ambient air.
The second cooling circuit 100 is provided for the vehicle components such as battery, fuel cells, power electronics, fluid systems etc. which is separated from the first temperature control circuit 90 for the internal combustion engine 9. Since the internal combustion engine operates at temperatures of around 90 degrees Celsius, while batteries and the other components of the vehicle operate at lower temperatures, in particular at temperatures of 15 degrees Celsius to 35 degrees Celsius, these two cooling circuits or temperature control circuits which can be separated from each other are appropriate in a hybrid vehicle. The second cooling circuit 100 comprises the evaporator 42 of the refrigerant circuit 2. The second cooling circuit 100 comprises a line 101, which leads through the evaporator 42. Downstream of the evaporator, this line is continued as line 102. This leads into a three-way valve 103, from which a line 104 leading through here, for example, the battery 6 branches off. By this means it is possible to supply cooled coolant to the battery or the components 600 of the vehicle connected in series or parallel thereto, such as in particular a fuel cell, power electronics etc. Another three-way valve 105 is provided for returning the coolant then heated by absorbing heat from the battery and switched in the direction of the pump 10 c in the second coolant circuit 100. As already explained previously for the embodiment of the climate control system 1 according to FIG. 1 or according to FIG. 6, heat can be released to the refrigerant circuit 2 via the evaporator 42 and thus the coolant in the coolant circuit 100 can be cooled for cooling the battery and the other components 600 of the vehicle.
In the refrigerant circuit 2 the two evaporators 42, 43 are connected in parallel, with the return of the refrigerant to the compressor 20 from the two evaporators 42, 43 being regulated by the three-way valve 44. The vehicle interior 4 is heated by the heat released from the internal combustion engine 9 to the coolant in the line 93, which can be supplied via the three-way valve 94 to the heating heat exchanger 30 instead of flowing directly into the line 95. The supply to the heating heat exchanger 30 is then therefore accomplished by means of a line 97. From the heating heat exchanger another line 98 leads back to the line 95 of the engine temperature control circuit 90.
If the vehicle interior is not to be heated but on the contrary climate controlled or cooled, the evaporator 43 of the refrigerant circuit 2 or the vehicle air-conditioning system is used for this purpose, where, as has already been described previously for the embodiment of the climate control system according to FIGS. 1 and 5, coolant is passed via the expansion valve 41 and the line 53 to the evaporator 43.
Not only cooling of the battery or the other components of the hybrid vehicle is possible but also heating of these components, shown here in FIG. 7 as representative for these by the battery 6, i.e. via the heating circuit 110. In principle, this can be used not only for the vehicle components but also for the internal combustion engine 9 for its heating, for example, in winter as part of an independent vehicle heater. The heating circuit 110 is configured so that it can provide a connection via the line 93, which passes through the internal combustion engine. The coolant flowing from the cooler 34, which cools during operation of the internal combustion engine 9, can be guided via the heating circuit 110, in which it is heated by the refrigerant cooler 21 and then supplied via the line 93 to the internal combustion engine 9. For this purpose, a line 111 of the heating circuit 110 branches off from the three-way valve 92. This leads through the refrigerant cooler 21 in order to absorb heat here from this. The line leads as line 112 to the three-way valve 113. From this three-way valve a line 114 branches off in the direction of the line 93 and a line 115 in the direction of the three-way valve 103. Both lines 114, 115 can be optionally opened if both the battery or the components of the vehicle and also the internal combustion engine are to be heated, for example, when starting in winter. It is furthermore possible to separate both cooling circuits by a corresponding device or valve position. For example, if battery 6 and internal combustion engine 9 are to be heated, this is usually not simultaneously the case since a drive unit is sufficient for starting up the vehicle so that for example, firstly the internal combustion engine 9 is heated. Thus, a priority switching of the circuits or of the components to be heated can be provided here.
If the internal combustion engine is subsequently sufficiently heated or the battery and the further components of the vehicle are subsequently sufficiently heated, the respective line 114 or 115 can be closed by means of the three-way valve 113. Heated coolant can be supplied to the battery or the other components of the vehicle via the line 115, the three-way valve 103, and the line 104 through the components or the battery to the three-way valve 105. From said valve the warm coolant is then guided via a line 116 to the line 93 or by means of a three-way valve provided accordingly there in connection with the line 93 optionally directly back to the three-way valve 92 and the line 111, in order to be heated by the heat released from the refrigerant cooler 21.
When heating the battery or the other components of the vehicle, the coolant circuit 100 is shut off by means of the two three- way valves 103 and 105. If neither the internal combustion engine nor the battery nor the other components of the vehicle are to be heated, the three-way valve 113 can be switched accordingly from the line 112 merely to the line 114 and this in the area of the connection to the line 93 by means of another three-way valve, which is also provided accordingly there but not indicated in FIG. 7, to the three-way valve 92 and from said valve to the line 111 so that a closed circuit is accomplished without further removal of heat by the internal combustion engine or battery or other components of the vehicle.
With this embodiment of a climate control system comprising two cooling circuits or temperature control circuits and one heating circuit as well as the refrigerant circuit which is thermotechnically connected therewith, components of the vehicle such as in particular the battery, fuel cells, power electronics etc., and the internal combustion engine of a hybrid vehicle as well as the vehicle interior can be temperature controlled by connecting and disconnecting the individual circuits and components of the climate control system.
FIG. 8 shows a variant of the climate control system according to FIG. 7, where a series connection of the two evaporators 42, 43 is provided here instead of the parallel connection in FIG. 7. The refrigerant heated by absorbing heat in the evaporator 42 from the coolant circuit 100 is passed on to the evaporator 43, where a further absorption of heat can take place in said evaporator if heat is to be extracted from the vehicle interior, i.e. the heating/cooling unit 31 is to act as a climate control system so that heated refrigerant is further supplied to the inner heat exchanger 25. From this, after further absorption of heat in the inner heat exchanger 25, the refrigerant can optionally be supplied to the compressor 20, as described otherwise for FIGS. 1 to 5. Since only the one expansion valve 40 is provided downstream of the inner heat exchanger 25 but the three-way valve 27 is omitted, after leaving the refrigerant cooler 23, which can act as liquefier or evaporator depending on whether the expansion valve 22 is bridged by the bridging valve 24 or not (in the heat pump mode), the refrigerant is fed directly via the inner heat exchanger 25 to the expansion valve 40. From this the refrigerant arrives at the evaporator 42 at low pressure and having a low temperature. In this evaporator heat can again be absorbed from the refrigerant circuit 100.
Compared to the embodiment according to FIG. 7, the embodiment according to FIG. 8 with the series connection of evaporators 42 and 43 is a more cost-effective variant since in particular the second expansion valve 41 and the three-way valve 27 can be omitted. Such a solution is also fundamentally possible for the embodiments in FIGS. 1 to 6 in order to provide a more cost-effective embodiment in each of these.
Instead of only one refrigerant cooler 21, two heat exchangers can also be provided and connected in series. By this means a better separation of the components, e.g. the internal combustion engine 9 and the battery 6 is possible.
In addition to the embodiments of climate control systems 1 shown in the figures and described hereinbefore, it is fundamentally also possible to directly control the temperature of the battery 6 by means of the refrigerant circuit 2, i.e. bypassing the temperature control/cooling circuit or heat transfer medium circuit 3. However, additional measures should be taken here to reduce the high pressure prevailing in the refrigerant by passing through the battery since this is poorly tolerated by the components to be temperature controlled. In addition to the described embodiments of climate control systems, numerous other systems can also be formed in which in each case at least one device for transmission of heat to the temperature control circuit and at least one device for transmission of heat from the temperature control circuit to the refrigerant circuit are provided. The fans, valve arrangements, and line guidance shown in the figures and described hereinbefore are merely to be seen as an example for the connection of the individual said components and heat exchangers of the climate control system. Appropriate other embodiments are also possible to achieve temperature control, in the same way as the removal and separation of subcircuits or bridged sections, in particular temperature control circuits, of the climate control system, where in each case at least one device for transmission of heat to the temperature control circuit and at least one device for transmission of heat from the temperature control circuit to the refrigerant circuit are always provided.

REFERENCE LIST

1 Climate control system
2 Refrigerant circuit
3 Temperature control circuit
4 Vehicle interior
5 Surroundings
6 Battery
7 Cooling circuit
8 Heating circuit
9 Internal combustion engine
10 Pump
10 a Pump
10 b Pump
10 c Pump
11 Electric motor
12 Compressor
21 First refrigerant cooler
22 First expansion valve
23 Second refrigerant cooler/condenser
24 Bridging valve
25 Inner heat exchanger
26 Bridging valve
27 Three-way valve
28 Line
29 Line
30 Heating heat exchanger
31 Heating/cooling unit
32 Fan
33 Bridging valve
34 Cooler
35 Fan
36 Bridging valve
37 Line
38 Bridging valve
39 Bridging valve
40 Second expansion valve
41 Third expansion valve
42 First evaporator
43 Second evaporator
44 Three-way valve
45 Line
46 Line
47 Line
48 Line
49 Line
50 Line
51 Line
52 Line
60 Line
61 Line
62 Line
63 Line
64 Line
70 Three-way valve
71 Three-way valve
72 Line
72 a Line
73 Line
74 Line
80 Line
81 Line
82 Line
82 a Line
83 Bridging valve
84 Line
85 Line
86 Line
87 Bridging valve
90 First temperature control/cooling circuit
91 Line
92 Three-way valve
93 Line
94 Three-way valve
95 Line
96 Line
97 Line
98 Line
100 Second cooling circuit
101 Line
102 Line
103 Three-way valve
104 Line
105 Three-way valve
110 Heating circuit
111 Line
112 Line
113 Three-way valve
114 Line
115 Line
116 Line
600 Component
601 Component (fluid system)
A Point downstream of compressor 20
E Point downstream of first refrigerant cooler 21
C Point downstream of first expansion valve 22
D Point downstream of second refrigerant cooler 23
E Point upstream of compressor 20
F Point downstream of second expansion valve 40
G Point downstream of first evaporator 42
FK Vehicle air-conditioning system

Claims

1. A climate control system for a vehicle, comprising: at least one refrigerant circuit and at least one temperature control circuit for controlling the temperature of a vehicle interior and at least one vehicle component,

wherein at least one device for absorbing heat from the temperature control circuit and at least one device for releasing heat to the temperature control circuit are provided, and

wherein the temperature control circuit comprises two cooling circuits for operating components of the vehicle at different levels.

2. The climate control system according to claim 1,

wherein the device for absorbing heat from the temperature control circuit is a low-pressure side heat exchanger, and/or the device for releasing heat to the temperature control circuit is a high-pressure side heat exchanger of the at least one refrigerant circuit.

3. The climate control system (1) according to claim 1,

wherein, at least one device for connecting and disconnecting at least one component and/or a subcircuit or circuit of the climate control system is provided.

4. The climate control system according to claim 1,

wherein a parallel circuit of two evaporators of the at least one refrigerant circuit is provided.

5. The climate control system according to claim 1,

wherein a series circuit of two evaporators of the at least one refrigerant circuit is provided.

6. (canceled)

7. (canceled)

8. The climate control system according to claim 1,

wherein the vehicle is a hybrid vehicle or an electric vehicle.

9. The climate control system according to claim 1,

wherein one or more pumps and one or more compressors are presented and can be operated electrically or are driven.

10. The climate control system according to claim 1,

wherein a refrigerant that can be used in the refrigerant circuit is selected from CO₂, a hydrofluoro olefin, and tetrafluoroethane.

11. A method for controlling the temperature of vehicle components using at least one refrigerant circuit and at least one temperature control circuit, comprising the steps of:

absorbing heat from the temperature control circuit on low-pressure side of the refrigerant circuit and

releasing heat to the temperature control circuit on a high-pressure side of the refrigerant circuit by said refrigerant circuit.

12. A vehicle having at least one temperature control system according to claim 1.

13. The climate control system according to claim 2, wherein the low-pressure side heat exchanger is an evaporator.

14. The climate control system according to claim 3, wherein the at least one device is at least one bridging valve and/or multi-way valve and/or a bypass line.

15. The climate control system according to claim 2, wherein at least one device for connecting and disconnecting at least one component and/or a subcircuit or circuit of the climate control system is provided, wherein a parallel circuit of two evaporators of the at least one refrigerant circuit is provided.

16. The climate control system according to claim 2, wherein at least one device for connecting and disconnecting at least one component and/or a subcircuit or circuit of the climate control system is provided, wherein a series circuit of two evaporators of the at least one refrigerant circuit is provided.

17. The climate control system according to claim 2, wherein one or more pumps and one or more compressors can be operated electrically or are driven, and wherein a refrigerant that can be used in the refrigerant circuit is selected from CO₂, a hydrofluoro olefin, and tetrafluoroethane.

18. A vehicle having at least one temperature control system according to claim 17.