WO2014154326A1

WO2014154326A1 - Vehicle air-conditioning device

Info

Publication number: WO2014154326A1
Application number: PCT/EP2014/000589
Authority: WO
Inventors: Michael BENS; Michael Hafner
Original assignee: Daimler Ag
Priority date: 2013-03-26
Filing date: 2014-03-07
Publication date: 2014-10-02
Also published as: DE102013005279A1

Abstract

The present invention relates to a vehicle air-conditioning device (1) for controlling the temperature of a vehicle interior (2), having a primary heating circuit (3) in which at least one heat source (7) is arranged, having a secondary heating circuit (4) in which at least one secondary heating heat exchanger (18) for heating the vehicle interior (2) is arranged, and having a cooling circuit (5) in which a coolant compressor (23), at least one condenser (24, 25), at least one expansion device (26) and at least one evaporator (27) are arranged. Improved efficiency is achieved when at least two condensers, specifically at least a first condenser (24) and a second condenser (25), are arranged in the cooling circuit (5), when the first condenser (24) is thermally coupled to the secondary heating circuit (4), and when the second condenser (25) is thermally coupled to the primary heating circuit (3).

Description

Vehicle air-conditioning device

The present invention relates to a vehicle air conditioning device for

Temperieren a vehicle interior.

The tempering of a vehicle interior is usually carried out by controlling the temperature of an air flow, which is supplied to said interior space. The term "temperature control" encompasses both cooling and heating of the vehicle interior or of the respective air flow. In the case of larger vehicles, such as, for example, for buses, it is necessary to temper the correspondingly large vehicle interior

comparatively much energy. For electric vehicles or hybrid vehicles with electric drive is for tempering the respective vehicle interior only

comparatively little energy is available to not unduly reduce the range of the vehicle. Accordingly, there is a need for such

Design air conditioning device as efficiently as possible.

Such a vehicle air conditioning device can, for example, with a

Primary heating be equipped in which at least one heat source, such as an internal combustion engine or a fuel-operated Zuheizeinrichtung is arranged. Typically, then at least one Primärheizwärmetauscher be involved in such a primary heating, with the help of the respective

Vehicle interior is heated. In modern vehicle air conditioning systems, more and more heat pump systems are being used to control the situation

Temperature differences can be used specifically for a heat transport. Ultimately, with the aid of such heat pumps, the efficiency of the air conditioning devices can be improved. Such a heat pump can be realized with the aid of a refrigeration circuit, which conventionally contains a refrigerant compressor, a condenser, an expansion device and an evaporator. The condenser of the refrigeration circuit can be involved in a secondary heating, in which a Secondary heat exchanger for heating the vehicle interior is located. In the secondary heating circuit can thus heat from the condenser to

Secondary heat exchangers are transported, so that over the

Secondary heat exchanger heat is discharged to the vehicle interior, while in the condenser, the heat is removed from the refrigerant circuit. Of the

In contrast, evaporator of the refrigeration circuit can be arranged in a cooling circuit in which, for example, a cooling heat exchanger is arranged, with the aid of which the respective vehicle interior can be cooled. Thus, heat can be transferred from the respective cooling heat exchanger to the evaporator in the cooling circuit. On the

Cooling heat exchanger is thereby withdrawn from the vehicle interior heat, causing it to be cooled. In the evaporator, however, heat is supplied to the refrigeration circuit. Heat can now be conveyed from the cooling circuit to the secondary heating circuit via the cooling circuit. With the help of the refrigeration circuit, which can also be referred to as a heat pump cycle or short as a heat pump, the temperature in the coolant of the cooling circuit can be lowered and / or raise the temperature in the heating of the Sekundärheizkreises to increase the temperature difference in the respective heat exchanger, which increases the efficiency Heat transfer improved.

The present invention deals with the problem for a

Vehicle air conditioning device comprising a Primärheizkreis, a Sekundärheizkreis and a refrigerant circuit to provide an improved embodiment, which is characterized in particular by increased energy efficiency.

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

The invention is based on the general idea of arranging at least two capacitors in the refrigerant circuit, wherein a first capacitor is assigned to the secondary heating circuit, while a second capacitor is assigned to the primary heating circuit. This results in the possibility of extracting heat from the refrigerant circuit both via the primary heating circuit and via the secondary heating circuit, as a result of which the refrigerant can be cooled more strongly, which improves the efficiency of the refrigeration circuit.

Particularly advantageous is an embodiment in which the first capacitor and the second capacitor are arranged in series in the refrigeration circuit, so that the two capacitors in each case from the entire volume flow of the refrigerant in succession be flowed through. Thus, the heat capacity of the

Primary heating circuit and the Sekundärheizkreises are used for the same of the entire refrigerant flow for cooling. By the series connection of the two

Capacitors is a two-stage cooling of the refrigerant, which ultimately lower the final temperature of the refrigerant or increasingly heat can bring into the heating circuit.

Particularly advantageous is an embodiment in which the second capacitor in the refrigerant circuit with respect to the flow direction of the refrigerant upstream of the first

Condenser is arranged. This embodiment is based on the consideration that the primary heating circuit is usually operated at a higher temperature level than the secondary heating circuit. By charging the second condenser with the comparatively warm refrigerant, a sufficient temperature difference prevails in the second condenser in order to achieve the desired cooling, in particular in conjunction with a condensation of the refrigerant. In the subsequent first condenser, the pre-cooled refrigerant encounters the colder secondary heating circuit compared to the primary heating circuit. However, here too a sufficient temperature difference is available which causes a further cooling and in particular a complete condensation of the refrigerant.

In another advantageous embodiment, the primary heating circuit can be fluidically coupled to the secondary heating circuit via a feed leading to the secondary heating circuit and a return leading to the primary heating circuit. By the fluidic

Coupling it is possible to transfer comparatively hot heating medium from the Primärheizkreis to the Sekundärheizkreis to cause a correspondingly intense heat transfer to the vehicle interior in Sekundärheizwärmetauscher. At the same time, this lowers the temperature of the heating medium routed through the secondary heating circuit. By using this reduced temperature in the first condenser, the refrigerant can be cooled down more.

According to an advantageous development, the secondary heating circuit can be connected fluidically downstream of the first condenser and downstream of the second condenser to the primary heating circuit. As a result, the second capacitor can be designed for the temperature and the volume flow of the heating medium in the primary heating circuit. Alternatively, it is also possible in principle to connect the secondary heating circuit downstream of the first condenser upstream of the second condenser to the primary heating circuit. In this case, the heating medium of the secondary heating circuit, even after the first Condenser may have a lower temperature than the heating means of the primary circuit, be used to reduce by admixing the heating means of the primary circuit, the temperature of the heating means of the primary circuit before it enters the second capacitor. In this way, the temperature difference between the refrigerant and the heating means of the Primärheizkreises be increased, which is the

Improved efficiency of heat transfer in the second capacitor.

In another advantageous embodiment, the secondary heating circuit may be serially coupled to the primary heating circuit. The serial coupling concerns only that volume flow that is actually passed through the secondary heating circuit. Usually, the heating medium circulates in the primary heating circuit with a significantly larger volume flow than in the secondary heating circuit. Accordingly, only a partial flow of the preferred

Primary circuit in series through the secondary circuit. The serial arrangement of primary circuit and secondary circuit is preferably to be seen with regard to the arrangement of at least one Primärheizwärmetauschers in Primärheizkreis, wherein the respective Primärheizwärmetauscher also serves to heat the vehicle interior. In other words, the partial flow of the primary heating circuit fed to the secondary heating circuit is branched off from the primary heating circuit downstream of the respective primary heating heat exchanger. By so created series connection of at least one

Primary heat exchanger and the at least one Sekundärheizwärmetauschers is achieved that the heating medium is supplied to the Sekundärheizkreis low temperature in order to improve the cooling of the refrigerant in the first capacitor. The respective Sekundärheizwärmetauscher can be particularly easily designed so that it despite reduced temperature in the heating means sufficient heating of the

Vehicle interior can realize. For example, the

Secondary heat exchanger be designed for a so-called reheat operation, which makes it particularly powerful. Such a reheat operation will be explained in more detail below in the description of the figures.

In another advantageous embodiment, a bypass may be provided, which fluidly connects the flow, bypassing the Sekundärheizkreises with the return. Through the bypass is thus a fluidic decoupling of

Secondary heating circuit of the primary heating possible.

Particularly advantageously, the second capacitor is now arranged in the bypass, ie in a region in which the heating means within the primary heating circuit

has relatively low temperature, which favors the cooling of the refrigerant. The relatively low temperature in the heating means results in the bypass in particular when the supply is arranged downstream of the respective aforementioned Primärheizwärmetauschers.

According to another advantageous development, a valve device for

Controlling a division of a supplied via the feed flow of heating medium to the secondary heating circuit and the bypass to be provided. With the aid of the valve device, at least the secondary heating circuit can be fluidically coupled to the primary heating circuit or decoupled therefrom. For the coupling state, a predetermined

Flow distribution may be provided. It is likewise possible to design the valve device in such a way that the flow distribution can be set or changed as desired either within predetermined limits or virtually arbitrarily. For example, a

Flow distribution 80:20 so that 80% of the volume flow is passed through the bypass, while only 20% of the volume flow is passed through the secondary heating circuit. It is clear that other distribution ratios may be provided or may be adjustable.

In another advantageous embodiment, the secondary heating circuit may have a heater. With the help of such a Zuheizers can for certain

Operating conditions quickly comparatively much heat in the secondary heating circuit

be introduced. It is conceivable, for example, a cold start of the vehicle, in which the primary heating circuit has ambient temperature. However, until the primary heating circuit has a sufficient temperature for heating the vehicle interior due to its large volume and the associated large heat capacity, it may take a relatively long time. In contrast, the secondary heating circuit has only a comparatively small volume or a comparatively small heat capacity, so that it can be heated comparatively quickly with the aid of the auxiliary heater, so that the desired heating of the vehicle interior can be realized correspondingly quickly via the respective secondary heating heat exchanger.

According to an advantageous development, a short-circuit line may be provided which comprises a return line coming from the at least one secondary heat exchanger, bypassing the first condenser and having at least one

Secondary heat exchanger leading flow line upstream of the auxiliary heater connects. As a result of this measure, the secondary heating circuit can also be operated without a first condenser if the associated cooling circuit is not available. In another development, a valve device for forwarding a supplied via the return line Heizmittelstroms be optionally provided by the short-circuit line or the first capacitor. In other words, these

Valve device controls the short-circuit line. Thus, with the help of this

Valve device between the short-circuit operation for heating the

Secondary heating circuit with activated heater and a normal heating operation can be switched, in which heat is removed from the refrigerant circuit with the heater off. This is also possible simultaneously to heat, for example, simultaneously.

Other important features and advantages of the invention will become apparent from the

Subclaims, from the drawing and from the associated figure description with reference to the drawing.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Preferred embodiments of the invention are illustrated in the drawings and will be explained in more detail in the following description.

The sole FIGURE 1 shows a greatly simplified schematic diagram of a vehicle air conditioning device.

According to FIG. 1, a vehicle air-conditioning device 1, with the aid of which a vehicle interior 2 of a vehicle, not shown here, can be heated, a primary heating circuit 3, a secondary heating circuit 4, a cooling circuit 5 and, in the example, a cooling circuit 6.

The primary heating circuit 3 contains at least one heat source 7. In the example, two heat sources 7 are indicated, which may be formed, for example, by an internal combustion engine 8 and by a heating device 9 which can be operated with a fuel. In the example, the heating device 9 is arranged in an internal combustion engine 8 immediate branch 10 of the Primärheizkreises 3, which can be activated and deactivated by means of a valve 11 as needed. This makes it possible, in particular, to realize a parking heater operation with the internal combustion engine 8 switched off. The primary heating circuit 3 also includes at least one primary heating heat exchanger 12 for Heating of the vehicle interior 2. For this purpose, an air flow 13, which is supplied to the interior space 2, are passed through the respective primary heating heat exchanger 12. In the primary heating circuit 3, a cooler 14 is also arranged, can be discharged via the heat from the primary heating circuit to an environment 15 of the vehicle. For this purpose, the radiator 14 is traversed by a suitable air flow 16, which exits into the environment 15. The radiator 14 is expediently the so-called vehicle radiator or main radiator. The primary heating circuit 3 is expediently an engine cooling circuit. Finally, the Primärheizkreis 3 includes in a conventional manner a conveyor 17 for driving the heating means in the Primärheizkreis third

The secondary heating circuit 4 includes at least one Sekundärheizwärmetauscher 18, which is traversed by an air flow 19, which is also supplied to the vehicle interior 2. In that regard, said air flow 19 and ultimately the interior 2 can be heated via the respective secondary heating heat exchanger 18. Of the

Secondary heating circuit 4 also includes a conveyor 20 for driving the heating means in the secondary heating circuit 4. In addition, here is a heater 21 in

Secondary heating 4 arranged. The heater 21 may be electrically or with a

Fuel operated.

The refrigerant circuit 5 includes in a direction indicated by arrows flow direction 22 of a refrigerant circulating in the refrigerant circuit 5 successively a refrigerant compressor 23 two capacitors, namely a first capacitor 24 and a second

Condenser 25, an expansion device 26 and at least one evaporator 27 and in the example a refrigerant collector 28th

The cooling circuit 6 includes at least one cooling heat exchanger 29, with which the air flow 19, which is supplied to the vehicle interior 2, can be cooled. In this case, the respective cooling heat exchanger 29 is expediently arranged upstream of the respective Sekundärheizwärmetauschers 18 with respect to the air flow 9. By this arrangement, a so-called reheat operation can be realized, in which the interior space 2 can be heated with a dehumidified or dried air stream 19. For this purpose, the air flow 19 is first cooled in the respective cooling heat exchanger 29 below the dew point of the water contained therein, whereby it can be condensed and removed from the air stream 19. Subsequently, the air flow 19 in the respective

Secondary heating heat exchanger 18 is heated to the desired temperature. Since with the help of the respective Sekundärheizwärmetauschers 18 for this reheat operation a comparatively high heat transfer performance is required, are the

Secondary heat exchanger 18 designed accordingly powerful.

The refrigeration cycle 6 also includes a conveyor 30 for driving a refrigerant in the refrigeration cycle 6.

In the case of the air-conditioning device 1 presented here, the first condenser 24 of the refrigeration circuit 5 is thermally integrated into the secondary heating circuit 4. The second

Capacitor 25 of the refrigerant circuit 5 is thermally integrated into the primary heating circuit 3. The evaporator 27 of the refrigerant circuit 5 is thermally integrated into the cooling circuit 6. The two capacitors 24, 25 are arranged in the refrigerant circuit 5 in series.

Accordingly, the entire refrigerant flow successively flows through first one and then the other condenser 24, 25. Expediently, the second condenser 25 with respect to the flow direction 22 of the refrigerant upstream of the first capacitor 24 in the refrigerant circuit 5 is arranged.

The primary heating circuit 3 and the secondary heating circuit 4 are fluidly coupled together. For this purpose, a leading from the Primärheizkreis 3 to Sekundärheizkreis 4 leading 31 of the Primärheizkreises 3 is connected to the Sekundärheizkreis 4. Furthermore, a return from the Sekundärheizkreis 4 to the Primärheizkreis 3 return 32 of the Primärheizkreises 3 is also connected to the Sekundärheizkreis 4. Thereby one connects

Connecting line 33 of the Sekundärheizkreises 4, the first capacitor 24 with the return 32, and that according to the illustrated in Figure 1 by a solid line, preferred embodiment downstream of the second capacitor 25. In Figure 1 is also shown with a broken line a variant in which the

Connecting line 33 'upstream of the second capacitor 25 is connected to the Primärheizkreis 3.

The fluidic coupling between Primärheizkreis 3 and Sekundärheizkreis 4 is based on the arrangement of the heating heat exchanger 12 and 18 serially designed. This means that the heating means of the primary heating circuit 3 only downstream of the respective

Primary heat exchanger 12 passes into the Sekundärheizkreis 4 and accordingly flows at a reduced temperature level to the Sekundärheizwärmetauscher 18.

The primary heating circuit 3 is here also equipped with a bypass 34, the flow 31, bypassing the Sekundärheizkreises 4 with the return line 32 fluidly combines. In this bypass 34, the second capacitor 25 is integrated into the primary heating circuit 3.

For fluidic coupling of the two heating circuits 3, 4, a first valve device 35 is provided, for example in the form of a 3/2-way valve. With the help of the first

Valve device 35 may be a division of a feed via the 31

Heizmittelstroms are controlled to the Sekundärheizkreis 4 and the bypass 34. It is also conceivable to use the first valve device 35 to completely decouple the secondary heating circuit 4 completely from the primary heating circuit 3. In this case, the entire Heizmittelstrom is passed from the flow 31 to the bypass 34.

In the example, a second valve device 36 is also provided, which may also be a 3/2-way valve. With the help of the second valve means 36, a Heizmittelstrom, which are fed via a coming from the Sekundärheizwärmetauscher 18 return line 37 optionally via a further line 38 to the first capacitor 24 or via a short-circuit line 39 back to the conveyor 20 and thus to a flow line 40 through the heater 21 leads to the respective Sekundärheizwärmetauscher 18.

In normal heating operation, in which the interior 2 is to be heated, the air stream 13 is heated via the respective primary heat exchanger 12, whereby the heating means cools down accordingly. The cooled heating medium is over the first

Valve device 35 is guided to a large extent by the bypass 34 and by the second capacitor 25. In the second condenser 25, the cooled heating means can cool the refrigerant to a comparatively high degree, wherein in particular already one

Condensation of at least a portion of the refrigerant can be realized. A usually smaller partial flow of the heating means is supplied via the first valve means 35 to the secondary heating circuit 4, whereby it to the respective

Secondary heat exchanger 18 passes and the air flow 19 can heat accordingly. At the same time, the heating means is cooled again. The heating medium then passes at reduced temperature to the first capacitor 24 by the

Refrigerant can continue to cool. The reheated heating medium thereby passes back via the connecting line 33 into the primary heating 3.

In order to heat the interior 2 as quickly as possible within the scope of a cold start of the vehicle, the valve devices 35, 36 are switched so that the heating medium is conveyed in the secondary heating circuit 4 in a greatly shortened circulation can. In this case, the heater 21 is also active to heat the heating means.

As a result, the heating means is heated in the flow line 40 before it enters the respective Sekundärheizwärmetauscher 18, where it can deliver the heat to the air stream 19. Via the return line 37, the cooled heating medium reaches the second valve device 36, which leads the heating medium back to the suction side of the conveyor 20 via the short-circuit line 39, from where the heating medium again reaches the heater 21 via the feed line 40. The first valve means 35 prevents a fluid exchange between the Primärheizkreis 3 and the Sekundärheizkreis 4. The / the capacitors depending on whether 33 or 33 'can in principle be involved if the valve 35 can also be switched so that HT ground can be decoupled. However, this only works if there is bypass for ground there.

Claims

Patent claims

Vehicle air conditioning device for controlling the temperature of a vehicle interior (2),

- with a primary heating circuit (3) in which at least one heat source (7) is arranged,

- with a secondary heating circuit (4) in which at least one

Secondary heating heat exchanger (18) for heating the vehicle interior

(2) is arranged,

- with a refrigeration circuit (5) in which a refrigerant compressor (23), at least one condenser (24, 25), at least one expansion device (26) and at least one evaporator (27) are arranged,

- wherein at least two capacitors, namely at least a first capacitor (24) and a second capacitor (25), are arranged in the refrigeration circuit (5),

- wherein the first capacitor (24) is thermally coupled to the secondary heating circuit (4),

- The second capacitor (25) is connected to the primary heating circuit

(3) is thermally coupled.

Device according to claim 1,

characterized in that

the first capacitor (24) and the second capacitor (25) are arranged in series in the refrigeration circuit (5).

Device according to claim 1 or 2,

characterized in that the second capacitor (25) in the refrigeration circuit (5) is arranged upstream of the first capacitor (24) with respect to the flow direction (22) of the refrigerant.

4. Device according to one of claims 1 to 3,

characterized in that

the primary heating circuit (3) via a flow (31) leading to the secondary heating circuit (4) and a return (32) leading to the primary heating circuit (3).

Secondary heating circuit (4) is fluidly coupled.

5. Device according to claim 4,

characterized in that

the secondary heating circuit (4) is fluidly connected to the primary heating circuit (3) downstream of the first capacitor (24) and downstream of the second capacitor (25).

6. Device according to claim 4 or 5,

characterized in that

the secondary heating circuit (4) is coupled in series with the primary heating circuit (3).

7. Device according to one of claims 4 to 6,

characterized in that

a bypass (34) is provided, which bypasses the flow (31).

Secondary heating circuit (4) fluidly connects to the return (32).

8. Device according to claim 7,

characterized in that

the second capacitor (25) is arranged in the bypass (34).

9. Device according to claim 7 or 8,

characterized in that

a valve device (35) is provided for controlling a division of a heating medium flow supplied via the flow (31) between the secondary heating circuit (4) and the bypass (34).

10. Device according to one of claims 1 to 9,

characterized, - that the secondary heating circuit (4) has an additional heater (21),

- that a short-circuit line (39) is provided which connects a return line (37) coming from the at least one secondary heating heat exchanger (18) with a flow line (40) leading to the at least one secondary heating heat exchanger (18) upstream of the additional heater (21),

- that a valve device (36) is provided for forwarding a heating medium flow supplied via the return line (37) either through the short-circuit line (39) or to the first capacitor (24).