DE10245257A1 - Thermal management device for a motor vehicle - Google Patents

Abstract

A heat management device for a motor vehicle is proposed, comprising a refrigerant circuit of an air conditioning system comprising a refrigerant compressor (3) for compressing substantially gaseous refrigerant, a refrigerant cooler (4) for removing heat from the refrigerant, in particular an ambient air heat exchanger, a refrigerant expansion valve (5) for Relaxation of substantially liquid refrigerant, and a refrigerant evaporator (6) for transferring heat to the refrigerant, wherein the refrigerant evaporator (6) is designed as a refrigerant / liquid heat exchanger, that via the refrigerant evaporator (6) heat with a second liquid circuit is interchangeable , DOLLAR A According to the invention, the second liquid circuit is formed as a cooling circuit for the internal combustion engine with a first liquid / air heat exchanger for heat exchange with the Innenraumzuluft of the motor vehicle. DOLLAR A application in passenger cars.

Description

The invention relates to a thermal management device according to the preamble of claim 1, and on the other hand, a method for operating such a thermal management device according to the preamble of claim 8.

From the publication DE 32 12 329 A1 For example, a cooling system for cooling a flowable medium by means of a refrigerant circuit leading circuit is known. The circuit carrying the refrigerant circuit has in succession a compressor, a condenser and an expansion valve. The expansion valve is dependent on the temperature of the medium to be cooled (oil) controllable in its throughput. The low-pressure evaporator is designed as a refrigerant / oil heat exchanger and allows heat transfer from the refrigerant to the oil.

The object of the invention is to provide a Thermal management device of the type mentioned above, the one for motor vehicle applications adapted, particularly flexible and safe thermal management as well as avoidance of moisture entry into the interior supply air allows.

This object is achieved by a thermal management device with the features of claim 1 and a method with the features of claim 8 solved.

The thermal management device according to the invention records through a second fluid circuit out, acting as a cooling circuit for the internal combustion engine with a first liquid / air heat exchanger for heat exchange is formed with the Innenraumzuluft the motor vehicle. there is the first refrigerant circuit both as a chiller as well as a heat pump operated. The second fluid circuit provides a so-called "second loop system" for the refrigerant circuit By such a "second-loop system" is avoided that the Refrigerant evaporator, for this purpose preferably as a liquid / liquid heat exchanger is formed, is acted upon directly by the Innenraumzuluft. It also ensures that the refrigerant evaporator is not with the interior air comes into contact. The proposed arrangement is particularly simple in construction, wherein an existing coolant circuit the internal combustion engine or its components can be used and a double function (on the one hand heat exchanger between the refrigerant circuit and Innenraumzuluft, on the other hand heat exchanger between the engine cooling circuit and interior air supply). In the second fluid circuit can be also as a liquid / liquid heat exchanger Switch on the trained refrigerant cooler.

In an embodiment of the invention in the second fluid circuit a second liquid / air heat exchanger provided over the heat is interchangeable with the interior air supply. Thus, two (within the second fluid circuit) parallel or serially operable heat exchangers between the second Fluid circuit and the interior air supply available. This results in an increased heat transfer area, if both heat exchangers for heat transfer between the refrigerant circuit and the interior supply air are used.

In a further embodiment of the invention is the second fluid circuit designed such that over the second liquid / air heat exchanger in parallel to the first liquid / air heat exchanger or alternatively to the first liquid / air heat exchanger Heat with the interior air supply is interchangeable. Preferably, a parallel control such that the first liquid / air heat exchanger with the refrigerant circuit and the second liquid / air heat exchanger are thermally coupled to the internal combustion engine.

In a further embodiment of the invention is the second refrigerant circuit designed such that over the first liquid / air heat exchanger alternatively Heat between the refrigerant circuit and the Innenraumzuluft or between the internal combustion engine and the Interior air is transferable. Here is the first heat exchanger preferably then for heat transfer between refrigerant circuit and indoor air supply, if this is a temperature above having the dew point of the ambient air.

In a further embodiment of the invention is the second fluid circuit in two separate subcircuits divisible, over the heat at the same time the refrigerant circuit and the interior air supply and between the internal combustion engine and the interior air supply is interchangeable. This allows a so-called "reheat operation" of the air conditioning system realize in which the interior air supply cooled one after the other and heated becomes.

In a further embodiment of the invention is in the second fluid circuit coolant circulated with a heat capacity, the is larger as that of water, leaving the second fluid circuit as a heat storage while Standstill phases of the internal combustion engine of the motor vehicle usable is. Preferably, as a coolant glycol used.

In a further embodiment of the invention, the first liquid / air heat exchanger and the second liquid / air heat exchanger are arranged in a common air-flow box through which the interior air supply flows. It is a space saving en, encapsulated construction possible in which a large part of the second liquid circuit is integrated in the air box. In this case, the refrigerant evaporator is preferably arranged outside of the air conditioning box, so that no entry of condensation occurs in the air conditioning box.

The inventive method is characterized through a second fluid circuit out, in which two liquid / air heat exchanger are arranged over the alternatively or simultaneously heat with the interior air supply is replaced and in that by means of the second fluid circuit Heat off the internal combustion engine discharged is. The second fluid circuit takes preferably a double function true: On the one hand is on the liquid / air heat exchanger Heat off the refrigerant circuit transferred to the interior air supply, and On the other hand, heat transferred from the internal combustion engine to the Innenraumzuluft. Furthermore, the second fluid circuit decouples the interior air supply from the refrigerant circuit, wherein at the same time an intermediate storage of heat or cold in the second fluid circuit (or part of it).

In an embodiment of the method is in the second fluid circuit coolant circulated with a heat capacity, the is larger as that of water, leaving the second fluid circuit as a heat storage while Standstill phases of the internal combustion engine of the motor vehicle usable is. In the liquid of the second fluid circuit There is an intermediate storage of heat or cold. This can only be done in a partial circle of the second fluid circuit occur.

In a further embodiment of the method is the second fluid circuit in two separate subcircuits divisible, over the heat at the same time the refrigerant circuit and the interior air supply and between the internal combustion engine and the interior supply air is exchanged. This is the interior supply particularly effective tempered and dryable.

The proposed refrigerant circuit is preferably both as a refrigeration process as well as a heat pump operate, with the second fluid circuit disadvantages when changing the operating mode (for example, condensation in the refrigerant evaporator and rapid evaporation of condensate in the refrigerant evaporator during heat pump operation) avoided become.

Further features and feature combinations result from the claims, the description as well as the drawings. Specific embodiments The invention are shown in simplified form in the drawings and explained in more detail in the following description. Show it:

1 a schematic representation of a thermal management device according to the invention with a first embodiment of a second fluid circuit and

2 A second embodiment of a second fluid circuit for use in a thermal management device according to the invention.

In 1 schematically is a thermal management device 1 illustrated for a motor vehicle, which has a refrigerant circuit 2 with known components in the form of refrigerant compressor or compressor 3 , Refrigerant cooler 4 , Refrigerant expansion valves 5a . 5b as well as evaporator 6a . 6b having. In addition, to improve the efficiency and process control, an internal heat exchanger 9a . 9b as well as a refrigerant collector 10 in the refrigerant circuit 2 connected. Suitable refrigerants are all commonly used refrigerants such as R134a or CO ₂ .

The refrigerant cooler 4 is designed as a refrigerant / ambient air heat exchanger and is permeable by ambient air, so that it is able to deliver heat to the environment. In a modified embodiment, it is designed as a refrigerant / liquid heat exchanger and turned on in a second fluid circuit, such as a coolant circuit of the internal combustion engine.

The expansion valves 5a . 5b are in their throughput and pressure gradient by means of a control / regulating device 11 controllable, each parallel to the expansion valves 5a . 5b check valves 7a . 7b are so connected in the circuit, that in each case opposite to their usual flow direction passable bypass is formed to the expansion valves. The control device 11 Incidentally, not only the expansion valves (a control line 8th is drawn by way of example), but also the switching valves, the compressor and the heat exchanger providable.

The refrigerant evaporator 6a . 6b is designed as a refrigerant / liquid heat exchanger and has a first, flowed through by the refrigerant section 6a and a second section through which a heat transfer fluid flows 6b on top of a second fluid circuit 10 assigned.

The second fluid circuit 10 is part of the cooling system of the internal combustion engine 12 of the motor vehicle, wherein a heat transfer fluid is circulated, for example, a mixture of glycol and water or pure glycol or the like. The heat capacity of the liquid is preferably greater than that of water.

In the second fluid circuit 10 is a first section 10a provided in addition to the internal combustion engine 12 , a first circulation pump 13 and a first liquid / air heat exchanger 14 are arranged in the form of a heating heat exchanger. A second section lOb of the second fluid circuit 10 includes one second circulation pump 18 , a shut-off valve 19 and a second liquid / air heat exchanger 15 , the first liquid / air heat exchanger 14 is connected in parallel and together with this in a so-called climate box 20 is housed. The climate box 20 is flowed through in a non dargestell ter way of the Innenzulüft, that the two liquid / air heat exchanger 14 . 15 at the same time and possibly spatially offset heat can exchange with the interior air supply. Furthermore, the two subsections of the second fluid circuit 10 over two, preferably by means of the control device 11 lockable, oppositely acting check valves 16 . 17 connected with each other.

A third section of the second fluid circuit 10 includes in a manner not shown an engine radiator, via the engine waste heat in particular to the ambient air can be discharged.

An essential basic function of the thermal management device 1 , namely the cooling process for cooling the interior air supply, is described in the following idealized:
The refrigerant is in the refrigerant compressor 3 compressed from low pressure to high pressure. The refrigerant heated by the compression gives over the refrigerant cooler 4 Isobar warms up to the environment. Subsequently, the refrigerant flows through the check valve 7b and the inner heat exchanger 9a through which it isobar emits heat to the refrigerant flowing in the low pressure area between evaporator and compressor inlet (heat exchanger section 9b ). Through the refrigerant expansion valve 5a the refrigerant is subsequently depressurized from high pressure to low pressure. The temperature sinks. The refrigerant is in the 2-phase state and passes through the refrigerant evaporator section 6a , Through its walls, it takes isobaric heat from the refrigerant evaporator section 6b on, creating heat from the second fluid circuit 10 is deducted.

Via a switching valve 21 the refrigerant becomes a refrigerant collector 10 (Accumulator), is stored in the non-process participating refrigerant. The refrigerant is then passed through the inner heat exchanger 9b passed, in which it is overheated. Afterwards the compressor sucks 3 the refrigerant again and the refrigeration process is run through again.

The liquid in the second liquid circuit is pumped by the pump 18 circulated and, with shut off check valve 17 , passed over the second liquid / air heat exchanger 15, where it extracts heat from the Innenraumzuluft. Optionally, when the pump is shut down 13 by opening the check valve 17 also a parallel admission of the first liquid / air heat exchanger 14 with cold liquid take place, so that a more efficient heat transfer takes place in the air box.

Furthermore, with shut-off check valves 16 . 17 a so-called "reheat operation" feasible by the over the refrigeration process in the refrigerant circuit 2 cooled liquid is passed exclusively through the second liquid / air heat exchanger 15, while of the internal combustion engine 12 heated liquid is transported via the first liquid / air heat exchanger 14. The liquid circuit is divided into two separate subcircuits, in which the liquid is circulated independently. Thus, the interior air supply in the air conditioning box can be cooled (and possibly dried) and then reheated.

In the heat pump process, the refrigerant in the refrigerant compressor 3 compressed from low pressure to high pressure. The refrigerant heated by the compression passes through the switching valve 22 via which it goes to the refrigerant evaporator 6a . 6b which acts as a cooler in the heat pump process. The refrigerant passes over the evaporator 6a . 6b isobar heat to the air supplied to the interior. Subsequently, the refrigerant flows through the bypass check valve 7a and then the inner heat exchanger 9a , About him there isobaric heat to the low pressure area 9b between refrigerant radiator and compressor inlet counterflowing refrigerant. Through the refrigerant expansion valve 5b the refrigerant is isenthalp relaxed from high pressure to low pressure. The temperature sinks. The refrigerant is in the 2-phase state and passes through the refrigerant cooler 4 acting as an evaporator. Over the walls of the refrigerant cooler 4 it absorbs isobar heat from the environment. About the switching valves 23 . 21 the refrigerant becomes the accumulator 10 , is stored in the not participating in the process refrigerant. The refrigerant continues through the inner heat exchanger 9b passed, in which it is overheated. Afterwards the refrigerant compressor sucks 3 the refrigerant back on.

The liquid in the second liquid circuit is in heat pump operation by means of the pump 18 circulated and, with the valve shut off 19 , passed over the first liquid / air heat exchanger 14, where it gives off heat to the Innenraumzuluft. Especially after previous cold operation (A / C operation), in which at the second liquid / air heat exchanger 15 Moisture, in particular condensation, may have been separated by the use of the first heat exchanger 14 for heat transfer to the Innenraumzuluft avoided that the condensation evaporates rapidly during the starting process and enters the interior of the vehicle. In this case, therefore, the heat exchanger already used in known systems for heat transfer to the Innenraumzuluft used during the (still cold) second heat exchanger 15 shut down. At the same time or alternatively, by an activity tion of the pump 13 heated liquid from the internal combustion engine via the liquid / air heat exchanger 14 be encouraged.

Optionally, by opening the switching valve 19 also a parallel admission of first liquid / air heat exchanger 14 and second liquid / air heat exchanger 15 done with heated liquid, so that a more efficient heat transfer takes place in the air box.

In a modified embodiment, the liquid / air heat exchangers are 14 . 15 associated with one or more latent heat storage, the gement device at the operating temperature of the Wärmemana perform a phase change and thus dampen temperature fluctuations of the heat transfer fluid in the second fluid circuit. The said latent heat storage are preferably as casings around the liquid / air heat exchanger or as a separate heat exchanger in the air box executable.

In 2 is a part of another embodiment of the thermal management device according to the invention 1 represented, wherein the same effect components in general the same reference numerals as in the embodiment according to 1 assigned.

The refrigerant circuit 2 is essentially as in the first embodiment after 1 designed and therefore not shown in detail. In 2 is essentially the second fluid circuit 10 'shown on the above the refrigerant evaporator 6a . 6b Heat is transferable. The second fluid circuit 10 ' is opposite to the second fluid circuit 10 after 1 modified in particular by a changed interconnection.

Core of the modified second fluid circuit 10 ' is a 6/4-way valve 24 , about the internal combustion engine 12 , first liquid / air heat exchanger 14 , second liquid / air heat exchanger 15 as well as liquid / liquid heat exchanger 6a . 6b are interconnected. The 6/4-way valve 24 has six connecting cables 25 - 30 on, which are connectable in four different circuits.

In a first circuit a of the valve 24 are the connection cables 25 With 30 such as 27 With 28 interconnected, so that a series connection of all components of the second fluid circuit 10 ' results. The fluid in the second fluid circuit 10 ' will be in 2 counterclockwise from the pumps 18 and 13 circulated, wherein the operating in heat pump mode refrigerant circuit 2 via the refrigerant / liquid heat exchanger 6a . 6b Heat to the second fluid circuit 10 ' can transfer. Likewise, via the internal combustion engine 12 Heat in the second fluid circuit 10 ' entered. The second fluid circuit 10 ' can this heat possibly. only partially deliver to the flowing through the air conditioning box Innenzuluft, so that this circuit is particularly suitable for use conditions of the motor vehicle with particularly low ambient temperatures (especially lower than -10 ° C) and / or extreme cold start conditions of the motor vehicle.

In a second circuit b of the valve 24 are the connection cables 25 With 29 such as 27 With 28 connected together. Here is the second liquid / air heat exchanger 15 (Interior heat exchanger) compared to circuit a removed from the circulation. Also in circuit b, the operating in heat pump mode refrigerant circuit 2 via the refrigerant / liquid heat exchanger 6a . 6b Heat to the second fluid circuit 10 ' transfer. Likewise, via the internal combustion engine 12 Heat in the second fluid circuit 10 ' entered. The second fluid circuit 10 ' Existing heat may be partially over the first liquid / air heat exchanger 14 (Heat exchanger) are delivered to the Innenraumzuluft, the second liquid / air heat exchanger is practically shut down. This circuit is particularly suitable for use conditions of the motor vehicle with temperatures below the dew point of the ambient air (in particular lower than + 10 ° C) and / or cold start conditions of the motor vehicle, in which a wet refrigerant evaporator 6a . 6b present or to be feared.

In a third circuit c of the valve 24 are the connection cables 25 With 27 such as 28 With 30 connected together. This is the second fluid circuit 10 ' divided into two separate, separate sub-circuits in which the heat transfer fluid can be circulated at different speeds. Here is the refrigerant circuit 2 according to 1 preferably operable as a refrigeration process, wherein the refrigerant / liquid heat exchanger 6a . 6b Heat from the second fluid circuit 10 ' removable and the second liquid / air heat exchanger 15 is coolable. Accordingly, the at the second liquid / air heat exchanger 15 cooled along indoor air supply and optionally dried. The first liquid / air heat exchanger 14 can be via the feed pump 13 with over the waste heat of the internal combustion engine 12 act upon heated liquid, whereby a heating (reheat) of the Innenraumzuluft can be realized as needed. In high outside temperatures and dry ambient air, the pump 13 turned off.

This circuit allows on the one hand a temperature control (heating or cooling) of the interior air supply via the second liquid / air heat exchanger 15, with the refrigerant circuit 2 coupled on the other hand, a heating of the interior air supply via the first liquid / air heat exchanger 14 that with the internal combustion engine 12 is coupled. Both Temperierungsmöglichkeiten can be used additive or alternatively, so this circuit is suitable for almost all temperature ranges.

In a fourth circuit d of the valve 24 are the connection cables 26 With 30 such as 27 With 28 connected together. As a result, in the second fluid circuit 10 ' the liquid / air heat exchanger 14 . 15 connected in series and via the refrigerant / liquid heat exchanger 6a . 6b with the refrigerant circuit 2 coupled. As a result, both heat exchangers are used for heat transfer, the heat transfer performance at the heat exchangers is thus increased compared to a circuit with only one heat exchanger.

By the described embodiments a thermal management device with a second fluid circuit Sensors for the detection of refrigerant superfluous in the air conditioning box or indoor air supply. There are also safety precautions to prevent refrigerant from entering the indoor supply airflow or reducible into the interior of the motor vehicle.

The second fluid circuit is not only used to the spatial and energetic decoupling of refrigerant circuit and interior air supply, but also for heat storage, to improve the dynamics of heat transfer and occupant protection.

Claims (10)

Thermal management device ( 1 ) for an internal combustion engine of a motor vehicle with - a refrigerant circuit ( 2 ) of an air conditioning system which - a refrigerant compressor ( 3 ) for the compression of essentially gaseous refrigerant, - a refrigerant cooler ( 4 ) for heat removal from the refrigerant, in particular an ambient air heat exchanger, - a refrigerant expansion valve ( 5 ) for the expansion of substantially liquid refrigerant, and - a refrigerant evaporator ( 6 ) for transferring heat to the refrigerant, wherein the refrigerant evaporator ( 6 ) is designed as a refrigerant / liquid heat exchanger such that via the refrigerant evaporator ( 6 ) Heat is exchangeable with a second liquid circuit, characterized in that - the second liquid circuit is formed as a cooling circuit for the internal combustion engine with a first liquid / air heat exchanger for heat exchange with the Innenraumzuluft of the motor vehicle. Thermal management device according to claim 1, characterized in that in the second fluid circuit a second liquid / air heat exchanger is provided over the heat is interchangeable with the interior air supply. Thermal management device according to claim 2, characterized in that the second liquid circuit is formed such that over the second liquid / air heat exchanger parallel to the first liquid / air heat exchanger or alternatively with the first liquid / air heat exchanger with heat the interior air supply is interchangeable. Thermal management device according to one of the claims 1 to 3, characterized in that the second refrigerant circuit is formed such that over the first liquid / air heat exchanger alternatively Heat between the refrigerant circuit and the Innenraumzuluft or between the internal combustion engine and the Interior air is transferable. Thermal management device according to one of the claims 1 to 5, characterized in that the second liquid circuit in two separate Teilkreiläufe is divisible, over the heat at the same time the refrigerant circuit and the interior air supply and between the internal combustion engine and the interior air supply is interchangeable. Thermal management device according to one of the claims 1 to 5, characterized in that in the second fluid circuit coolant is circulated with a heat capacity, which is bigger than that of water, so that the second fluid circuit as a heat storage while Standstill phases of the internal combustion engine of the motor vehicle usable is. Thermal management device according to one of the claims 1 to 6, characterized in that the first liquid / air heat exchanger and the second liquid / air heat exchanger in a common air-conditioning box through which the interior air can flow are arranged. Method for operating a thermal management device ( 1 ) for a motor vehicle, in particular a thermal management device according to one of claims 1 to 7, - in which via a refrigerant circuit ( 2 ) an air conditioning system, the supply air to the interior of the motor vehicle is heated and / or cooled and - in which the refrigerant circuit via a refrigerant evaporator ( 4 ) Gives off heat to a second fluid circuit, characterized in that - in the second fluid circuit two liquid / air heat exchangers are arranged, via which alternatively or simultaneously heat is exchanged with the Innenraumzuluft and that - by means of the second fluid circuit heat from the internal combustion engine can be discharged. Method according to claim 8, characterized in that that in the second liquid circuit coolant is circulated with a heat capacity, the is larger as that of water, leaving the second fluid circuit as a heat storage while Standstill phases of the internal combustion engine of the motor vehicle usable is. Method according to claim 8 or 9, characterized that the second fluid circuit in two separate subcircuits is divisible, over the heat at the same time between the refrigerant circuit and the interior air supply and between the internal combustion engine and the Interior air is exchanged.