WO2015132113A1 - Refrigeration plant - Google Patents

Abstract

The invention also relates to a refrigeration plant (22) and a refrigeration plant system (100) comprising a switchable heat exchanger (10, 10a, 10b) of said type for a refrigeration plant (22), heating pipes (12) and cooling pipes (14) in said heat exchanger being integrated into a single housing (16) in such a way that heat is transferred between the heating pipes (12) and the cooling pipes (14). The invention also relates to a refrigeration plant (22) and a refrigeration plant system (100) comprising a heat exchanger (10, 10a, 10b) of said type.

Description

The invention relates to a switchable heat exchanger and a refrigeration system with at least one compressor, at least one expansion element and at least one switchable heat exchanger, which are interconnected in a refrigerant circuit. The invention also relates to a refrigeration system with such a refrigeration system and a vehicle with such a refrigeration system or such a refrigeration system.

Refrigeration systems, which are used for example in refrigerated vehicles or buses, generally have a plurality of heat exchangers, the temperature, for example, for cooling a cold room or for air conditioning or heating a cab. For this purpose, heat exchangers are operated either in a cooling mode or in a heating mode. In cooling mode, the heat exchanger is therefore an evaporator while it acts as a condenser in heating mode. In particular, in the cooling mode, the heat exchanger can reach temperatures that lead to the formation of an ice sheet. The ice layer reduces the heat transfer from the heat exchanger to the environment. For defrosting, switching to heating mode is necessary.

DE 10 2008 047 753 A1 describes a refrigeration system with at least two useful temperature levels, which comprises at least one first refrigerant circuit and a second refrigerant circuit separated therefrom. The first and second refrigerant circuits are further coupled to each other via a cascade heat exchanger, so that heat from one refrigerant circuit to the other refrigerant circuit can be transferred, or heat can be absorbed by a medium surrounding the heat exchanger, or can be delivered to the medium surrounding the heat exchanger , In particular, in order to defrost the heat exchanger for controlling the temperature of a deep-freeze area, the refrigeration system comprises a circuit in which the compressed in the electrically operated compressor refrigerant is passed directly through the heat exchanger to be defrosted without this is previously relaxed in the expansion device.

From DE 10 2011 107 081 A1 a rooftop air conditioning system is known which comprises a compressor, evaporator and condenser. The evaporator comprises a first heat exchanger, which is operated in the cooling mode as an evaporator. In addition, a dehumidifying operation is provided in which a further heat exchanger upstream of the first heat exchanger is operated as an evaporator and the first heat exchanger is operated as a condenser. The two heat exchangers are not connected to one another in a heat-conducting manner.

DE 102 54 109 A1 describes a combined cooling / heating device with a shared cooler, via which heat of a refrigerant is released into the environment in an air-conditioning operation and heat is taken up by the refrigerant from the environment in a heat pump operation. For deicing the gas cooler with respect to the refrigerant flow heat exchanger are connected in parallel. Switching devices affect the flow through the individual heat exchangers as a function of detected environmental parameters. The two heat exchangers are not connected to one another in a heat-conducting manner.

US 2009/0320504 A1 relates to a method for defrosting an evaporator in a refrigeration cycle. Within the cooling circuit, a refrigerant circulates in a predetermined flow direction. The refrigeration cycle includes a compressor in the flow direction, a heat-rejecting heat exchanger, an expansion device and an evaporator. The evaporator comprises at least two cooling circuits and the method comprises the following method steps: a) driving the cooling circuit in the normal cooling mode, in which the refrigerant leaves the heat-rejecting heat exchanger and flows through the expansion device and the evaporator to the compressor; b) terminating the cooling mode by interrupting the flow of the refrigerant leaving the heat rejecting heat exchanger in the direction of the evaporator; and c) passing the gaseous refrigerant through only part of the evaporator cooling circuits to defrost the evaporator.

The known measures for defrosting heat exchangers in refrigeration systems require switching the heat exchanger from the cooling mode to the heating mode. The temperature change, however, the components are heavily used and it can cause damage. In order to prevent this, heat exchangers for the cooling operation and the heating operation may be provided separately from each other. This, however, requires more space and makes the design of the system more difficult. There is therefore a continuing interest in providing a simple and durable design for such refrigeration systems.

The known measures for defrosting heat exchangers in refrigeration systems require switching the heat exchanger from the cooling mode to the heating mode. The temperature change, however, the components are heavily used and it can cause damage. In order to prevent this, heat exchangers for the cooling operation and the heating operation may be provided separately from each other. This, however, requires more space and makes the design of the system more difficult. There is therefore a continuing interest in providing a simple and durable design for such refrigeration systems.

According to the invention, a switchable heat exchanger for a refrigeration system is proposed in which heating tubes and cooling tubes are integrated in such a way in a single housing that heat by heat conduction, z. B. is transmitted via fins (fine aluminum sheets) between the heating pipes and the cooling tubes.

• wenigstens einen Verdichter zum Komprimieren eines Kältemittels,
• wenigstens ein Expansionsorgan zum Entspannen des Kältemittels,
• wenigstens einen umschaltbaren Wärmetauscher, in dem Heizrohre und Kühlrohre derart in einem einzigen Gehäuse integriert sind, dass Wärme zwischen den Heizrohren und den Kühlrohren übertragen wird, und
• wenigstens ein Ventil zum Umschalten zwischen einem Heizbetrieb und einem Kühlbetrieb des umschaltbaren Wärmetauschers.

In addition, the invention proposes a refrigeration system for controlling the temperature of air with at least one refrigerant circuit, which comprises the following components:

• at least one compressor for compressing a refrigerant,
• at least one expansion element for releasing the refrigerant,
• at least one switchable heat exchanger in which heating tubes and cooling tubes are integrated in a single housing such that heat is transferred between the heating tubes and the cooling tubes, and
• at least one valve for switching between a heating operation and a cooling operation of the switchable heat exchanger.

The integration of heating and cooling pipes in a single housing of the switchable heat exchanger, the switching between the heating operation and the cooling operation of the switchable heat exchanger is much easier. Thus, the tubes of the switchable heat exchanger are used only for cooling or only for heating, whereby a large temperature difference when switching from heating to cooling mode and vice versa is avoided. As a result, the individual components are not subject to large temperature jumps and damage can be avoided. Since the heating pipes are not used as cooling pipes, the heating pipes can be designed optimized for the flow conditions and pressures in the heating case. The same applies to the cooling tubes optimizing evaporating refrigerant with significantly lower pressures than the heating tubes, so that the cooling tubes can be performed in a thinner wall thickness. The output of the compressor is consistently connected only to the input side of the heating pipes or connectable. The input of the compressor, however, is consistently connected only to the output side of the cooling tubes or connected and can only suck vaporized refrigerant. In a mixed use of the cooling tubes and the heating tubes, this would not always guaranteed. Also, the flow direction is not reversed, which favors the oil transport back to the compressor. Overall, this leads to a significant improvement in the reliability of the compressor even with possible malfunction of the switching valves. By sharing the slats both through the heating tubes and through the cooling tubes, the air-side exchange surface in the heating and in the cold trap is significantly increased compared with a separate slat design. Furthermore, a faster defrosting is possible by the heat conduction from the heating tubes on the common blade on the cooling tubes.

Integrated in the refrigeration system, the proposed reversible heat exchanger also has the advantage that the functionality is expanded. Thus, different operating conditions can be realized, which allow a pure cooling or heating and a regulation between the pure cooling and heating. Cooling and heating are possible at the same time. This allows a continuous power adjustment between maximum cooling capacity and maximum heating power. The design of the refrigeration system is considerably simplified, since significantly fewer switching valves are needed. Minimal only a three-way valve is required, or there are only two valves used, which may optionally be designed as a lockable expansion valves.

In one embodiment, the switchable heat exchanger comprises at least two refrigerant inputs and at least two refrigerant outlets. Thus, a refrigerant inlet and a refrigerant outlet may be provided for the heating tubes and the cooling tubes, respectively, whereby the refrigerant flow through the heating tubes and the refrigerant flow through the cooling tubes is performed separately.

In a further embodiment, the switchable heat exchanger is designed as a plate heat exchanger. In particular, the heating tubes and the cooling tubes can be arranged at least partially in alternating sequence in lamellae of the switchable heat exchanger. Thus, the heating tubes and the cooling tubes can be arranged completely in alternating sequence. This is particularly advantageous in the application of the switchable heat exchanger as an external air heat exchanger, such as in air conditioning systems for vehicles such as buses, as a de-icing operation can be easily realized. Alternatively, the switchable heat exchanger may provide first regions in which the heating tubes and the cooling tubes are arranged entirely in alternating sequence, and second regions in which only heating tubes or only cooling tubes are arranged. Such a mixed arrangement is particularly advantageous in the application of the switchable heat exchanger as Zuluftwärmetauscher about in air conditioning systems for vehicles, such as buses, since a Reheatbetrieb in which air is dried by simultaneous heating and cooling, can be easily realized.

In a variant of the refrigeration system, the at least one valve for switching between a heating operation and a cooling operation is designed such that in a first switching position for the heating operation, the refrigerant flows substantially through the heating tubes, in a second switching position for the cooling operation, the refrigerant substantially the cooling tubes flows and, in a switching position between the first and the second switch position for a reheat operation, the refrigerant flows through the heating tubes and the cooling tubes.

In a further variant of the refrigeration system, at least one first valve for switching between a heating operation and a cooling operation is designed such that it controls a refrigerant flow through the heating tubes, and at least one second valve for switching between a heating operation and a cooling operation is designed such that it controls a flow of refrigerant through the cooling tubes. In particular, a first valve can be connected downstream of the heating tubes in the direction of refrigerant flow, and a second valve can be connected upstream of the cooling tubes in the direction of refrigerant flow. Preferably, the valves have an open and a closed switching position.

In a further variant of the refrigeration system, a compressor is connected upstream of the heating tubes of the heat exchanger, so that compressed refrigerant can flow into the heating tubes of the switchable heat exchanger, and an expansion element upstream of the cooling tubes of the switchable heat exchanger so that expanded refrigerant can flow into the cooling tubes of the switchable heat exchanger , The expansion element can be designed, for example, as an electrically controllable expansion valve, in particular as a stepper motor valve or as a pulsed solenoid valve.

In a further variant, the refrigeration system comprises at least a first and a second switchable heat exchanger with integrated heating tubes and cooling tubes, which are interconnected such that heats in the cooling operation of the first switchable heat exchanger, the second switchable heat exchanger and vice versa. Such a refrigeration system may include a compressor, two valves for switching between cooling operation and heating operation and two expansion elements. The cooling tubes of the first and the second switchable heat exchanger can each be preceded by an expansion element so that expanded refrigerant can flow into the cooling tubes of the first or second switchable heat exchanger. Furthermore, the valves for switching between cooling operation and heating operation control the refrigerant flow through the cooling tubes and the heating tubes of the first and the second switchable heat exchanger. Here, the refrigerant circuits of the cooling tubes and the heating tubes of the first and second switchable heat exchanger are designed such that the cooling tubes of the second switchable heat exchanger are acted upon when the heating tubes of the first switchable heat exchanger are acted upon and vice versa.

In a further variant, the refrigeration system comprises at least one internal heat exchanger, which may be designed, for example, as a plate heat exchanger or double tube heat exchanger. If two switchable heat exchangers are provided in the refrigeration system, two internal heat exchangers can be operated countercurrently, in which the refrigerant, after flowing through the heating tubes of the first switchable heat exchanger, is conducted countercurrently to the refrigerant after flow of the cooling tubes of the second switchable heat exchanger. Conversely, two internal heat exchangers can be operated countercurrently in such a way that the refrigerant, after flowing through the heating tubes of the second switchable heat exchanger, is conducted countercurrently to the refrigerant after the cooling tubes of the second switchable heat exchanger have flowed through.

Another object of the invention is a refrigeration system with the above-described refrigeration system, to which an extended refrigerant circuit is coupled to at least one other heat exchanger. As a further heat exchanger are, for example, plate heat exchanger or double tube heat exchanger for heat transfer to a heat transfer fluid, z. B. water glycol. In this case, at least two further heat exchangers may be provided, of which one is designed for cooling and / or one for heating. As a result, the functionality of the refrigeration system is extended to other systems, for example in the vehicle, especially in the bus. Thus, the other heat exchangers can be used as a cold or hot water heat exchanger for a drive system or as Zuluftwärmetauscher for cooling or heating a cab.

In one implementation of the refrigeration system, the coupling comprises a first branch, which is connected downstream of the heating tubes of the switchable heat exchanger of the refrigeration system, and / or a second branch, which is connected upstream of the cooling tubes of the switchable heat exchanger of the refrigeration system.

In a further implementation of the refrigeration system, the extended refrigerant circuit comprises at least one further heat exchanger for heating and at least one further heat exchanger for cooling. In a further implementation of the refrigeration system, at least one valve for controlling the flow of refrigerant is associated with the at least one further heat exchanger. In particular, a valve is connected downstream of the further heat exchanger for heating in the direction of refrigerant flow and a valve upstream of the further heat exchanger for cooling in the direction of refrigerant flow. The valves can be designed as controllable shut-off valves, whereby the heating and the cooling capacity of the other heat exchangers can be regulated.

In a further implementation of the refrigeration system, the first and / or second branch a line system with check valves downstream, and the check valves are switched depending on the operation of the refrigeration system that the at least one further heat exchanger to a refrigerant circuit with the heating tubes and / or to a refrigerant circuit is coupled to the cooling tubes of the heat exchanger of the refrigeration system. By means of the non-return valves, the refrigerant flow in the extended refrigerant circuit can be correspondingly controlled depending on the operating mode of the refrigeration system, ie heating or cooling operation. Due to the design of the valves for controlling the flow of refrigerant in the extended refrigerant circuit as check valves, a very robust, cost-effective and simple control of the refrigerant flow in the extended refrigerant circuit is possible.

In a further implementation of the refrigeration system, the first and / or second branch is preceded by an electrically controllable valve, for example a solenoid valve, and an electrically controllable valve is switched depending on the operation of the refrigeration system such that the refrigerant flow of the at least one further heat exchanger to the refrigerant circuit , which comprises the heating tubes of the switchable heat exchanger of the refrigeration system, and / or to the refrigerant circuit, which comprises the cooling tubes of the switchable heat exchanger of the refrigeration system, is coupled. The design of the valves for controlling the extended refrigerant circuit as electrically controllable valves, the line system over the embodiment with check valve can be simplified and fewer valves are used. Such a configured refrigeration system is structurally easier to implement and saves space.

In a further implementation of the refrigeration system, the valves for switching between a heating mode and a cooling mode of the refrigeration system and the valves for regulating the refrigerant flow in the extended refrigerant circuit are designed as electrically controllable valves. Thus, a central control of the heat exchanger can be realized. For example, the overheating of the total volume flow upstream of the compressor and the individual volume flows of refrigerant per evaporator heat exchanger and just required power level can be controlled. Likewise, the subcooling or the optimal high pressure of the total volume flow and the individual volume flows per gas cooler heat exchanger and just required power level can be controlled.

This can be configured, for example, such that the individual opening degrees of the control valves are determined by the respective power requirement of the individual heat exchanger and a factor with which these individual opening degrees of the individual control valves involved are to be multiplied is determined for the superordinate control target of superheating or subcooling. This can also advantageously lead to individual evaporators with high power requirements without overheating, d. H. completely evaporating refrigerant can be operated. A special feature is the outdoor air heat exchanger whose power requirement is subordinate to all others. In the other heat exchangers in the system, it may, for. B. be that the cooling or heating of drive components, such. As battery electrics, engine and brake and the like more priority. Furthermore, z. B. an air conditioning of a driver's compartment have priority over the air conditioning of a passenger compartment. Or, however, the cooling of the cargo compartment or cargo compartments of a refrigerated transporter may possibly take precedence over the air conditioning of the driver's compartment.

If at least two evaporators are normally operated in parallel, they can also be defrosted alternately with the embodiment proposed according to the invention without the operation being interrupted. Examples include the following scenarios: For example, two evaporators can be operated in parallel in the hold of a refrigerated transporter, wherein the first evaporator is defrosted via the heating tubes, while the second evaporator continues to maintain the cooling via the evaporator tubes. Furthermore, it is possible to operate two evaporators in the outdoor heat exchanger in parallel. As a rule, an air conditioning system of a bus with a heat pump is designed in this way. In this example, for example, the first outdoor heat exchanger of the heat pump can be defrosted through the heating pipes, while the other evaporates further, without the heating operation of the air heat exchanger is interrupted.

Another example is given by an external evaporator and a cold water heat exchanger in which heat is removed by evaporation of the battery / engine cooling water and operated in parallel in a working as a heat pump air conditioners. The outdoor evaporator can be defrosted via the heating pipes while the battery is being further cooled and the heat pump continues to be heated via the heating pipes of the supply air heat exchanger.

Another object of the invention is a vehicle, in particular a bus, a rail vehicle or a refrigerated transporter, equipped with the above-described refrigeration system or equipped with the refrigeration system described above.

EMBODIMENTS Embodiments of the invention will be explained in more detail with reference to drawings.

FIG. 1a is a perspective view of a reversible heat exchanger in the form of a laminated tube and tube bundle design with heating tubes and cooling tubes; FIG. 1b shows a switchable heat exchanger according to FIG. 1a with alternating heating and cooling tubes in a sectional view; Figure 1c shows a switchable heat exchanger according to Figure 1a with partially arranged heating and cooling pipes in a sectional view; Figure 2 shows a refrigeration system with the switchable heat exchanger of Figures 1a, 1b and 1c in a first embodiment; FIG. 3 shows the refrigeration system of FIG. 2 in a heating mode of the first switchable heat exchanger; FIG. 4 shows the refrigeration system of FIG. 2 in a cooling mode of the first switchable heat exchanger; FIG. 5 shows the refrigeration system of FIG. 2 in a reheat mode; Figure 6 shows an embodiment of a refrigeration system with the refrigeration system of Figure 2 and an exemplary extended refrigerant circuit with a hot water heat exchanger and a cold water heat exchanger. Figure 7 shows another embodiment of a refrigeration system with a refrigeration system and an exemplary extended refrigerant circuit; Figure 8 shows another embodiment of a refrigeration system with a refrigeration system and an exemplary extended refrigerant circuit; Figure 9 shows another embodiment of a refrigeration system with a refrigeration system and an exemplary extended refrigerant circuit, Figure 10 is a plan view of a switchable heat exchanger in flat tube design. 11 shows a sectional view of the switchable flat tube heat exchanger according to FIG. 10 with alternating heating and cooling tubes; FIG. Figure 12 is a sectional view through the heating manifold of the flat tube heat exchanger of Figure 10; FIG. 13 is a sectional view through the cooling manifold with the flow-through scheme of the cooling tubes of the flat tube heat exchanger according to FIG. 10. The figures illustrate the invention only schematically. Identical or similar reference symbols are used for identical or similar components, unless stated otherwise. FIG. 1a shows a switchable heat exchanger 10 with heating tubes 12 and cooling tubes 14 in a perspective view. FIG. 1b shows the switchable heat exchanger 10 with heating tubes 12 and cooling tubes 14 in a sectional view.

The heat exchanger 10 is configured as a plate heat exchanger, the heating tubes 12 and cooling tubes 14 integrated in a single housing 16. The heating tubes 12 are made thick-walled due to the higher operating pressure. The housing 16 furthermore has a respective refrigerant inlet and a refrigerant outlet for the heating tubes 12 and the cooling tubes 14. The heating tubes 12 and cooling tubes 14 are connected to one another and to the housing 16 via lamellae 18, as shown in the sectional view of FIG. 1b.

In Figure 1b, the heating tubes 12 and the cooling tubes are arranged alternately. This means that the heating tubes 12 and the cooling tubes 14 are arranged alternately next to one another. Here are other arrangements conceivable.

Figure 1c shows a sectional view of a switchable heat exchanger with an alternative cooling / heating pipe guide.

In FIG. 1 c, the heating tubes 12 and the cooling tubes 14 are arranged in different regions of the lamellae 18. According to this embodiment, the reheat operation can be carried out particularly advantageously. As part of the reheat operation, the supply air first flows through the region of the cooling tubes 14 and is cooled to below the dew point temperature, so that moisture contained in the supply air can condense out. Subsequently, the cooled supply air flows through the area of the heating tubes 12 and is reheated, so that finally warm dry air flows out.

Furthermore, the heating tubes 12 and the cooling tubes 14 are each connected via a switchable refrigerant circuit 20 to a refrigeration system 22, the switchable heat exchanger 10 can be switched between a cooling operation and a heating operation.

The heating tubes 12 and the cooling tubes 14 carry a refrigerant, for example R134a, R1234yf, R1234ze, R152a, R161, R170, R290, R600, R600a, R744 transcritical, carbon dioxide (R744), nitrous oxide (R744jA), R23, R32 or mixtures such as: R410A, R404A, R407A, R407C and R407F. Particularly preferred is carbon dioxide or R134a.

By connecting the heating tubes 12 and the cooling tubes 14 with the fins 18, the switchable heat exchanger 10 can transmit heat to the environment or record from the environment. Thus, the switchable heat exchanger 10 allows the heating operation, in which only the heating tubes 12 are traversed with refrigerant, and the cooling operation, in which only the cooling tubes 14 are traversed with refrigerant. Switching the switchable heat exchanger 10 from the cooling mode to the heating mode and vice versa can thus be made simple, without burdening the components of the switchable heat exchanger 10 and in particular the refrigerant-carrying tubes by the change in temperature.

Figure 2 shows a refrigeration system 22 with the switchable heat exchanger 10 of Figure 1 in a first embodiment.

The refrigeration system 22 comprises a first switchable heat exchanger 10a, which can be used, for example, as a supply air heat exchanger or cold room heat exchanger, and a second switchable heat exchanger 10b, which can be used, for example, as an external air heat exchanger. Both switchable heat exchangers 10a, 10b comprise heating tubes 12 and cooling tubes 14, which are connected via a switchable refrigerant circuit 20 to a refrigeration system 22. For this purpose, the switchable refrigerant circuit 20 comprises a compressor 24 for compressing the refrigerant, expansion elements 26a, 26b, for example expansion valves, for releasing the refrigerant and valves 28a, 28b, for example solenoid valves, for switching between heating mode and cooling mode.

In addition, the switchable refrigerant circuit 20 in the illustrated embodiment has internal heat exchangers 30a, 30b. The internal heat exchangers 30a, 30b are merely optional and may be configured as plate heat exchangers or double tube heat exchangers. The internal heat exchangers 30 a, 30 b make the evaporation of the refrigerant more effective so that no liquid refrigerant enters the compressor 24. The zone of superheated refrigerant is displaced from the evaporator-the cooling pipe of 10a or 10b-into the internal heat exchangers 30b and 30a, respectively, which increases the performance of the evaporator. At the same time, the refrigerant exiting from the heating tubes of the heat exchanger 10b or 10a is further cooled in heat exchangers 30b and 30a, respectively.

FIG. 3 shows the refrigeration system 22 of FIG. 2 in a heating mode of the first switchable heat exchanger 10a.

In the heating operation of the first switchable heat exchanger 10a, the valve 28a, which is connected upstream of the cooling tubes 14 of the first switchable heat exchanger 10a, closed. The refrigerant is compressed in the compressor 24 and fed via pipes 32 to the heating tubes 12 of the first switchable heat exchanger 10a. Subsequently, the refrigerant is conducted via conduits 34, the downstream first internal heat exchanger 30a, the open valve 28b and the downstream expansion element 26b into cooling tubes 14 of the second switchable heat exchanger 10b. At the output of the second switchable heat exchanger 10b, the refrigerant is passed in countercurrent via the first internal heat exchanger 30a and piping 36 back to the compressor 24.

In this configuration, the refrigeration system 22 is switched so that the first switchable heat exchanger 10a gives off heat to the atmosphere (supply air) and the second switchable heat exchanger 10b absorbs heat from the outside (outside air). The second switchable heat exchanger 10b thus operates as an evaporator and the first switchable heat exchanger 10a as a gas cooler.

FIG. 4 shows the refrigeration plant 22 of FIG. 2 in a cooling operation of the first switchable heat exchanger 10a.

In the cooling mode of the first switchable heat exchanger 10a, the valve 28b, which is connected downstream of the heating tubes 12 of the first switchable heat exchanger 10a and upstream of the cooling tubes 14 of the second switchable heat exchanger 10b, is closed. The refrigerant is compressed in the compressor 24 and fed via pipes 38 to the heating tubes 12 of the second switchable heat exchanger 10b. Subsequently, the refrigerant via pipes 40, the downstream first internal heat exchanger 30b, the open valve 28a and the downstream expansion device 26a in cooling tubes 14 of the first switchable heat exchanger 10a out. At the outlet of the first switchable heat exchanger 10 a, the refrigerant is passed in countercurrent via the second internal heat exchanger 30 b and piping 42 back to the compressor 24.

In this configuration, the refrigeration system 22 is switched so that the second switchable heat exchanger 10b gives off heat to the outside air and the first switchable heat exchanger 10a absorbs heat from the outside (supply air). The first switchable heat exchanger 10a thus operates as an evaporator and the second switchable heat exchanger 10b as a gas cooler.

According to the illustration in FIG. 4, the outside air heat exchanger 10b can also be defrosted after icing in order then to operate again as a heat pump evaporator in accordance with FIG. 3. According to FIG. 3, the cold room heat exchanger 10a can be defrosted even after an occurrence of icing, in order then to operate again as an evaporator in accordance with operation, as shown in FIG.

FIG. 5 shows the refrigeration system 22 of FIG. 2 in a reheat mode.

In reheat mode, air is dehumidified in the vicinity of the first and second switchable heat exchangers 10a, 10b. For this purpose, both valves 28a, 28b are open and regulate the flow of refrigerant. Thus, the first and the second switchable heat exchangers 10a, 10b can be operated depending on the refrigerant flow both in the heating mode and in the cooling mode, as described above. The cooling operation serves to condense moisture, whereas the heating operation allows the heating of air. In this mode of operation, the heating capacities and the cooling capacities can be adapted almost infinitely to the requirements. For this purpose, the control valves 28a and 28b are opened correspondingly less than the respective other valve, d. H. the control valves 28a and 28b. By metering the volume flows through the control valves 28a and 28b, the desired cooling capacities or the desired heating powers can be regulated at the supply air heat exchanger 10a.

FIG. 6 shows an embodiment of a refrigeration system 100 having one of the refrigeration system 22 of FIG. 2 and an exemplary extended refrigerant circuit 25 having a hot water heat exchanger 44 and a cold water heat exchanger 46.

In the embodiment of FIG. 6, however, further branches 25 a, 25 b are coupled to the switchable refrigerant circuit 20, which comprises the hot water heat exchanger 44 and the cold water heat exchanger 46. The hot water heat exchanger 44 and the cold water heat exchanger 46 are not designed switchable and can be designed as a plate heat exchanger or double tube heat exchanger.

For coupling the hot water heat exchanger 44 and the cold water heat exchanger 46, a further branched line system 50 with check valves 50a and 50b is provided, which connects to the branches 62 and 63 of the switchable refrigerant circuit 20. Thus, in the cooling and heating operation of the first switchable heat exchanger 10a, refrigerant flows from the compressor 24 to the hot water heat exchanger 44 of the branch 25a when the valve 52a is opened. The refrigerant can continue to flow via the valves 50b and 52b to the branch 25b of the cold water heat exchanger 46 or via the expansion element 26b and the cooling tubes 14 of the switchable second heat exchanger 10b. Outflow via the expansion device 26a and the cooling tubes 14 of the first switchable heat exchanger 10a is prevented by the check valve 50a, so that the heating operation of the heat exchanger 10a is not disturbed. The cold water heat exchanger 46 of the branch 25b is further connected such that the check valve 50a in the cooling operation of the heat exchanger 10a and the check valve 50b is opened in the heating operation of the heat exchanger 10a. A further expansion element 56, which is connected upstream of the cold water heat exchanger 46 and downstream of the valve 52b, depressurises the refrigerant before it enters the cold water heat exchanger 46. Subsequently, the refrigerant is returned from the cold water heat exchanger 46 to the compressor 24. The solenoid valves 52a and 52b are used to control the flow of refrigerant through the hot water and cold water heat exchanger 44, 46 and are each upstream or downstream.

With the aid of the extended refrigerant circuit 25 different functions can be integrated in a single refrigeration system 100, whereby the construction of refrigeration systems 100, for example in vehicles such as buses, is substantially simplified and refrigeration systems 100 can be made more compact.

FIG. 7 shows a further embodiment of a refrigeration system 100 with a refrigeration system 22 and an exemplary expanded refrigerant circuit 25.

In the embodiment of FIG. 7, however, further branches 25a, 25b, 25c, 25d, 25e, 25f are coupled to the switchable refrigerant circuit 20, the further heat exchangers 44a, 44b, 44c, 46a, 46b, 46c. For coupling the heat exchangers 44a, 44b, 44c, 46a, 46b, 46c, a branched power system 50 with check valves 50a and 50b is provided, as already described with reference to FIG. In addition, solenoid valves 52a, 52b, 52c, 52d, 52e, 52f, which are upstream or downstream of the heat exchangers 44a, 44b, 44c, 46a, 46b, 46c, control the flow of refrigerant.

In the embodiment of FIG. 7, the further heat exchangers 44a, 44b, 44c, 46a, 46b, 46c can assume different functions. For example, the heat exchangers 44a and 46a may be configured as cold and hot water heat exchangers as described with reference to FIG. The further heat exchangers 44b and 46b may, for example, serve as heaters 44b and radiators 46b of air for a driver's cab in the vehicle. Accordingly, the refrigeration system 100 can be extended to almost any other heat exchanger 44c, 46c for cooling or heating.

FIG. 8 shows a further embodiment of a refrigeration system 100 with a refrigeration system 22 and an exemplary expanded refrigerant circuit 25.

The structure of the refrigeration system 100 corresponds to that of Figure 7. In the embodiment of Figure 8, however, instead of the conduit system 50 with check valves 50a and 50b, controllable solenoid valves 58a, 58b in the pipes 60a, 60b are arranged. Thus, the solenoid valve 58a in the pipe 60a associated with the first switchable heat exchanger 10a is connected between the valve 28a and the expansion member 26a. The coupling with the extended refrigerant circuit 25 via a connecting line 63 which branches off between the solenoid valves 28a and 58a. The solenoid valve 58b in the pipe 60b associated with the second switchable heat exchanger 10b is connected between the valve 28b and the expansion member 26b. The coupling with the extended refrigerant circuit 25 via a connecting line 62 which branches off between the solenoid valves 28b and 58b. With the aid of the solenoid valves 58a, 58b, the coupling between the refrigeration system 22 and the extended refrigerant circuit 25 can be made simpler and more flexible. Thus, in contrast to the embodiments of the refrigeration system according to Figures 6 and 7, in the embodiment of Figure 8 and the switchable second heat exchanger 10b are easily defrosted after an occurrence of icing in the cooling operation of the heat exchanger 10b very simple and effective, without the heating operation of the first switchable Interrupt heat exchanger 10a. For this purpose, the refrigerant is passed starting from the compressor 24 via the heating tubes 12 of the first and second switchable heat exchanger 10a, 10b. The solenoid valves 28a and 28b are opened. By the closed solenoid valves 58a and 58b, the cooling tubes 14 of both switchable heat exchanger 10a, 10b are shut off. The refrigerant can be returned to the compressor 24 via an active evaporator 46a, 46b or 46c. For this purpose, especially the cold water heat exchanger 46, the waste heat from other processes, eg. B. from the battery cooling or engine cooling, provides. This is not possible in the embodiment according to FIG. 7, since the refrigerant would flow away from the heating tubes 12 of the heat exchanger 10b via the cooling tubes 14 of the heat exchanger 10b and thus disturb the heating operation of the heat exchanger 10a.

FIG. 9 shows a further embodiment of a refrigeration system 100 with a refrigeration system 22 and an exemplary expanded refrigerant circuit 25.

The structure of the refrigeration system 100 corresponds to that of Figure 8. In the embodiment of Figure 9, however, further simplifications are provided. Thus, the valves 28a, 28b, 58a, 58b and 52a to 52f designed as electronically controllable control valves, whereby the refrigerant flow in the individual branches of the refrigeration system 100 can be controlled. The expansion members 26a, 26b and 56a to 56c may be omitted. As a result, a central control can be realized, which regulates the overheating before the compressor 24 and thus the total volume flow and the individual streams in the individual branches of evaporator heat exchangers depending on the required power level. Likewise, the subcooling or the optimal high pressure in the refrigeration system 100 and thus the total volume flow and the individual streams in the individual branches of gas cooler heat exchangers can be regulated depending on the required power level.

In addition, the refrigeration system 22 of FIG. 9 only provides a single internal heat exchanger 70, which is connected directly upstream of the compressor 24. The internal heat exchanger 70 is thus provided in the common line and leads the total volume flow of the refrigerant in countercurrent. Thus, in the event of a brief overheating at the compressor inlet, individual evaporator heat exchangers can be operated without overheating with liquid refrigerant, ie without overheating. The subcooling and thus the optimal high pressure can continue to be regulated according to pressure and temperature at the high pressure input of the internal heat exchanger 70. The overheating can be regulated according to pressure and temperature at the low-pressure outlet of the internal heat exchanger 70.

FIGS. 10 to 13 show a flat tube heat exchanger with heating tubes and cooling tubes.

The representation according to FIG. 11 shows that a flat-tube heat exchanger 80 shown there has an alternating sequence of heating tubes 12 and cooling tubes 14. Due to the higher pressure levels, the heating tubes 12 are designed in a thicker wall thickness, which also emerges from the illustration in FIG 11. The inlet of the heating tubes 12 is on the left side in Figure 10 through the manifold 90. Figure 12 shows a section through the Heizsammelrohr 90. The incoming refrigerant is distributed in this embodiment, three parallel heating tubes 12. On one side, the heating tubes 12 are each connected by small connecting tubes 88 so that a deflection can take place. The refrigerant, which flows through three heating tubes 12 back to the left side, is there again bundled on a heating tube 12, flows back to the right via a connecting tube 88 and again through a heating tube 12 to the left to Heizsammelrohr 90 back again by a heating tube 12 right over a connecting tube 88 and again through a heating tube 12 to the left to the heating manifold 90, where it finally exits.

The inlet of the cooling tubes 14 is on the right side in Figure 10 through the manifold 92. The incoming refrigerant is distributed in this embodiment, on two parallel cooling tubes 14. Die Kühlrohre 14 sind in Fig. 10 dargestellt. On the left side, the cooling tubes 14 are connected to each other by small connecting tubes 88 so that a deflection can take place. The refrigerant, which flows through two cooling tubes 14 back to the right side is there again distributed to four cooling tubes 14, flows back to the left, via connecting tubes 88 and again through four cooling tubes 14 to the right to the cooling manifold 92 back, where it finally exits. In an intermediate layout of the evaporator manifold. An aperture 86 is provided which promotes homogenous distribution of vapor and liquid of the two-phase refrigerant through turbulence generation.

In the illustration according to FIG. 10, a flat-tube heat exchanger can be seen. 11 shows the arrangement of Heizflachrohre and Kühlflachrohre in section of the flat tube heat exchanger of Figure 13. Figure 12 shows a sectional view of the flat tube heat exchanger according to Figure 13 with the Heizsammelrohren 90 with flow direction. Via the heating tubes 12 and the connecting tubes 88, the refrigerant flows to the second heating manifold 90b back to the first heating manifold 90a, the second heating manifold 90b, and finally to the first heating manifold 90a and to the outlet 84. FIG. 13 shows a sectional view of the flat tube heat exchanger according to FIG. 10, wherein the cooling collecting tubes 92 are connected to the inlet 82. Via the cooling tubes 14 and the connecting tubes 88, the refrigerant flows to the second cooling manifold 92 b through the aperture 86 and back to the first manifold 92 a and finally to the outlet 84.

The regulation of the refrigeration system 22 according to FIG. 2 is already partly shown in FIGS. 3 to 5. FIG. 3 shows a maximum heating. The heating pipes 12 of the supply air heat exchanger 10a and the cooling pipes 14 of the outside air heat exchanger 10b are flowed through, since the valve 28b is fully opened and the valve 28a is completely closed. Figure 4, however, represents the maximum cooling. The cooling tubes 14 of the air heat exchanger 10a and the heating tubes 12 of the outdoor air heat exchanger 10b are flowed through, since the valve 28a is fully open and the valve 28b is completely closed. Figure 5 illustrates an intermediate stage in which both the heating tubes 12 and the cooling tubes 14 of the air heat exchanger 10 a and the outdoor air heat exchanger 10 b are flowed through. It is important to ensure that never both valves 28a and 28b are completely closed while the compressor 24 is running. A step control can be taken from the following list:

Table 1

mode		28a	28b
Heating 4	0%	100%
Heating 3	25%	100%
Heating 2	50%	100%
Heating 1	75%	100%
Neutral	100%	100%
Cooling 1	100%	75%
Cooling 2	100%	50%
Cooling 3	100%	25%
Cooling 4	100%	0%

The neutral mode can alternatively be done with the compressor 24 and possibly closed valves 28a and 28b. The defrosting of the outdoor air heat exchanger 10b takes place in cooling mode 4 (FIG. 4), but with ventilators switched off at the heat exchangers 10a and 10b. The shutdown of the fan of the outdoor air heat exchanger 10b is mandatory.

You can also control the valves 28a and 28b alternately, so that one is always open, while the other is closed. Then the regulation could be made according to the following list:

Table 2

mode		28a	28b
Heating 4	0%	100%
Heating 3	20%	80%
Heating 2	33%	67%
Heating 1	40%	60%
Neutral	50%	50%
Cooling 1	60%	40%
Cooling 2	67%	33%
Cooling 3	80%	20%
Cooling 4	100%	0%

When the system according to FIGS. 6 and 7 is expanded, the regulation of the switchable heat exchangers 10a and 10b can be carried out as in the previously shown tables. The additional heating heat exchangers 44 (a, b, c,...) Can also be regulated stepwise or steplessly via their respectively associated valves 52a (c, e,...) By opening them with x% (0% to 100%). Analogously, additional cooling heat exchangers 46 (a, b, c,...) Can also be regulated stepwise or steplessly via these respectively assigned valves 52b (d, f,...) By opening them with x% (0% to 100%). It is important when defrosting the outdoor air heat exchanger 10b that the valve 28a is open, while all the other valves 28b, 52a, 52c, 52e, ... the heating heat exchanger 44 (a, b, c, ...) are closed. The cooling valves 52b, 52d, 52f, ... are not affected.

If at least one of the additional heating valves 52a, 52c, 52e, ... is open, the opening of the valves 28a and 28b can be reduced, which can be seen in the following list:

Table 3

mode		28a	28b	52 (a, c, e, ...)
Heating 4	0%	100%	100%
Heating 3	0%	75%	100%
Heating 2	0%	50%	100%
Heating 1	0%	25%	100%
Neutral	0%	0%	100%
Cooling 1	25%	0%	100%
Cooling 2	50%	0%	100%
Cooling 3	75%	0%	100%
Cooling 4	100%	0%	100%

In Figure 8, an extension of the refrigeration system 22 can be seen around the valves 58a and 58b. It can be dispensed with check valves. By shutting off the cooling tubes 14 in the heat exchangers 10a and 10b through the valves 58a and 58b, priority cooling of a further cooling heat exchanger 46 is possible. This is particularly advantageous when e.g. the cold water heat exchanger for battery cooling should have top priority. In this case, the outdoor air heat exchanger 10b can be defrosted without interrupting the heating operation:

Table 4

mode		28a		28b		58a	58b	52 (a, c, e)	52 (b, d, f)
Heating 4	0%	100%	0%	100%
Heating 3	0%	100%	25%	100%
Heating 2	0%	100%	50%	100%
Heating 1	0%	100%	75%	100%
Neutral	100%	100%	100%	0%
Cooling 1	100%	75%	100%	0%
Cooling 2	100%	50%	100%	0%
Cooling 3	100%	25%	100%	0%
Cooling 4	100%	0%	100%	0%
defrosting	100%	100%	100%	0%

Table 5

mode		28a		28b		58a	58b	52 (a, c, e)	52 (b, d, f)
Heating 4	0%	100%	0%	100%	100%
Heating 3	0%	100%	25%	100%	100%
Heating 2	0%	100%	50%	100%	100%
Heating 1	0%	100%	75%	100%	100%
Neutral	100%	100%	100%	0%	100%
Cooling 1	100%	75%	100%	0%	100%
Cooling 2	100%	50%	100%	0%	100%
Cooling 3	100%	25%	100%	0%	100%
Cooling 4	100%	0%	100%	0%	100%
defrosting	100%	100%	100%	0%	100%

Table 6

mode		28a		28b		58a	58b	52 (a, c, e)	52 (b, d, f)
Heating 4	0%	100%	0%	0%		100%
Heating 3	0%	100%	25%	0%		100%
Heating 2	0%	100%	50%	0%		100%
Heating 1	0%	100%	75%	0%		100%
Neutral	100%	0%	0%	0%		100%
Cooling 1	100%	0%	25%	0%		100%
Cooling 2	100%	0%	50%	0%		100%
Cooling 3	100%	0%	75%	0%		100%
Cooling 4	100%	0%	100%	0%		100%
defrosting	100%	100%	0%	0%		100%

The regulation of a refrigeration system 100 according to FIG. 9 is analogous to the regulation in connection with FIG. 8. However, the opening of the electronic expansion valves can be continuously adapted to the requirements. The sum of the opening degrees of the valves 28a, 28b and 52a, 52c and 52e determine the high pressure within the refrigeration system 100, which can be controlled to match the temperature at the high pressure inlet of the heat exchanger 70. If the pressure is higher than the predetermined pressure, the opening degrees are proportionally increased. If the pressure is too low, the opening degrees of the valves 28a, 28b, 52a, 52c, 52e are proportionally reduced. Thus, an optimal high pressure can be regulated, e.g. 5K supercooling. The sum of the opening degrees of the valves 58a, 58b and 52b, 52d and 52f determine the low pressure of the refrigeration system 100, which can be controlled to match the temperature at the low pressure output of the heat exchanger 70. If the pressure is higher than the predetermined pressure, the opening degrees are proportionally reduced. If the pressure is too low, the opening degrees will be proportionally increased. Thus, optimal overheating in front of the compressor 24 can be regulated, e.g. 5K overheating. The superheat control has priority over the high pressure control.

LIST OF REFERENCE NUMBERS Table 7

10	switchable heat exchanger
10a	1. switchable heat exchanger
10b	2. switchable heat exchanger
12	heating pipes
14	cooling pipes
16	casing
18	slats
20	Refrigerant circulation
22	refrigeration plant
24	compressor
25a	1. branch
25b	2nd branch
25c	3rd branch
25d	4. branch
25e	5th branch
25f	6. branch
26a	1. expansion organ
26b	2. expansion organ
28a	(1.) solenoid valve
28b	(2.) solenoid valve
30a	(1.) internal heat exchanger
30b	(2.) internal heat exchanger
32	pipeline
34	pipeline
36	pipeline
38	pipeline
40	pipeline
42	pipeline
44	Hot water heat exchanger
44a	1. hot water heat exchanger
44b	2. Hot water heat exchanger
44c	3. Hot water heat exchanger
46	Cold water heat exchanger
46a	1. cold water heat exchanger
46b	2. Cold water heat exchanger
46c	3. Cold water heat exchanger
48
50	line system
50a		check valve
50b		check valve
52a	1st valve
52b	2nd valve
52c	3rd valve
52d	4th valve
52e	5th valve
52f	6th valve
54
56	further expansion organ
58a	(1.) solenoid valve
58b	(2.) solenoid valve
60a, b		pipeline
62	Branch, connection line
63	junction
70	internal heat exchanger
80	Flat tube heat exchanger
82	entry page
84	exit side
85	Durchströmungsweg
86	cover
88	connecting pipe
90	Heizsammelrohr
92	Cooling manifold
94	fin arrangement
96
98
100	Refrigeration plant system

Claims (25)

1. Switchable heat exchanger (10, 10a, 10b) for a refrigeration system (22), characterized in that separate heating tubes (12) and cooling tubes (14) are integrated in a single housing (16) such that heat is present between the heating tubes (12) and the cooling tubes (14) is transmitted for cooling or heating an air flow.
2. Switchable heat exchanger (10) according to claim 1, wherein the switchable heat exchanger (10) comprises at least two refrigerant inputs and at least two refrigerant outlets.
3. Switchable heat exchanger (10) according to claim 1 or 2, wherein the switchable heat exchanger (10) is designed as a fin heat exchanger and fins (18) transfer heat between the heating tubes (12) and the cooling tubes (14) by heat conduction.
4. Switchable heat exchanger (10) according to one of claims 1 to 3, wherein the heating tubes (12) and the cooling tubes (14) at least partially in alternating order in lamellae (18) of the switchable heat exchanger (10) are arranged.
5. A switchable heat exchanger (10) according to any one of claims 1 to 4, wherein the heating tubes (12) and the cooling tubes (14) are arranged entirely in alternating sequence.
6. Switchable heat exchanger (10) according to one of the preceding claims, characterized in that the switchable heat exchanger (10) provides first regions in which the heating tubes (12) and the cooling tubes (14) are arranged completely in alternating sequence, and second regions are provided , in which only heating tubes (12) or only cooling tubes (14) are arranged.
7. Switchable heat exchanger (10) according to one of the preceding claims, that this is designed as a flat tube heat exchanger (80) and the heating tubes (12) have a thicker wall thickness, compared with the cooling tubes (14) or cooling tube channels.
8. Refrigeration system (22) for controlling the temperature of air with at least one refrigerant circuit comprising: - at least one compressor (24) for compressing a refrigerant, - at least one expansion element (26a, 26b) for expanding the refrigerant, - at least one switchable heat exchanger (10, 10a, 10b) according to any one of claims 1 to 7, and - at least one valve (28a, 28b) for switching between a heating operation and a cooling operation of the switchable heat exchanger (10, 10a, 10b).
9. Refrigeration system (22) according to claim 8, wherein the at least one valve (28a, 28b) is designed for switching between a heating operation and a cooling operation such that in a first switching position for the heating operation, the refrigerant flows substantially through the heating tubes (12), in a second switching position for the cooling operation, the refrigerant flows essentially through the cooling tubes (14) and in a switching position between the first and the second switching position for reheat operation, the refrigerant flows through the heating tubes (12) and the cooling tubes (14).
10. A refrigeration system (22) according to claim 8 or 9, wherein at least a first valve (28a) for switching between a heating operation and a cooling operation is arranged to control refrigerant flow through the heating pipes (12), and at least one second valve (28b). for switching between a heating operation and a cooling operation is designed such that it controls a flow of refrigerant through the cooling tubes (14).
11. Refrigeration system (22) according to one of claims 8 to 10, wherein the heating tubes (12) of the switchable heat exchanger (10, 10a, 10b) is preceded by a compressor (22), so that compressed refrigerant into the heating tubes (12) of the switchable heat exchanger (12). 10, 10a, 10b), and the cooling tubes (14) of the switchable heat exchanger (10, 10a, 10b) is preceded by an expansion element (26a, 26b), so that expanded refrigerant into the cooling tubes (12) of the switchable heat exchanger (10, 10a, 10b) flows.
12. Refrigeration system (22) according to one of claims 8 to 11, wherein the refrigeration system (22) comprises at least a first and a second switchable heat exchanger (10, 10a, 10b) with integrated heating tubes (12) and cooling tubes (14) interconnected in such a way are that in the cooling operation of the first switchable heat exchanger (10a), the second switchable heat exchanger (10b) is in heating mode and vice versa.
13. Refrigeration system (100) with a refrigeration system (22) according to one of claims 8 to 12, to which an extended refrigerant circuit (25) with at least one further heat exchanger (44, 44a, 44b, 44c, 46, 46a, 46b, 46c) is coupled ,
14. Refrigeration system (100) according to claim 13, wherein the extended refrigerant circuit (25) at least one further heat exchanger (44, 44a, 44b, 44c,) for heating, upstream of the compressor (24) and the cooling tubes (14) of the switchable heat exchanger (10 , 10a, 10b) are connected downstream via the lines (62, 63) and the expansion elements (26a, 26b) and / or at least one further heat exchanger (46, 46a, 46b, 46c) for cooling downstream of the compressor (24) and the heating tubes (12) of the switchable heat exchangers (10, 10a, 10b) are connected upstream, and wherein the at least one further heat exchanger (44, 44a, 44b, 44c, 46, 46a, 46b, 46c) for heating or cooling at least one valve (52a ... 52f) is assigned to control the flow of refrigerant.
15. Refrigeration system (100) according to one of claims 13 or 14, wherein the first and / or second branch (62, 63), a line system (50) with check valves (50a, 50b) is connected downstream, and the check valves (50a, 50b) as appropriate Operation of the refrigeration system (22) are connected so that the at least one further heat exchanger (44, 44 a, 44 b, 44 c, 46, 46 a, 46 b, 46 c) to a refrigerant circuit with the heating tubes (12) and / or with the cooling tubes (14 ) of the switchable heat exchanger (10, 10a, 10b) of the refrigeration system (22) is coupled, or wherein the first and / or second branch, a solenoid valve (58a, 58b) is connected upstream, and the solenoid valve (58a, 58b) depending on the operation of the Refrigeration system (22) is connected so that the refrigerant flow of the at least one further heat exchanger (44, 44a, 44b, 44c, 46, 46a, 46b, 46c) to the refrigerant circuit with the heating tubes (12) and / or with the cooling tubes (14 ) of the switchable heat exchanger (10, 10 a, 10 b) of the Kälteanla ge (22) is coupled.
16. Refrigeration system (100) according to one of claims 13 to 15, wherein the valves (28a, 28b) for switching between a heating operation and a cooling operation of the switchable heat exchanger (10, 10a, 10b) of the refrigeration system (22) and the valves (52a .. .52f) are designed to control the flow of refrigerant in the extended refrigerant circuit (25) as electrical valves.
17. Vehicle equipped with a refrigeration system (22) according to one of claims 8 to 12 or equipped with a refrigeration system (100) according to one of claims 13 to 16.
18. A method for operating a refrigeration system (22) according to one of claims 8 to 12 or a refrigeration system (100) according to one of claims 13 to 16, according to which the heating power or the cooling capacity of the air heat exchanger (10a) is regulated by the heating valve (28b). and / or the cooling valve (28a, 58a) is operated continuously or stepped between 0% and 100% opening.
19. The method of claim 18, wherein the heating valve (28b) and the cooling valve (28a, 58a) are operated inversely of each other, the heating valve (28b) is closed when the cooling valve (28a, 58b) is open and vice versa.
20. A method according to claim 18, characterized in that the priority of the heating listing of the heat exchangers in the order of additional heat exchangers (44, 44a, 44b, 44c) is switchable air heat exchanger (10a) and outside air heat exchanger (10b).
21. A method according to claim 18, characterized in that the priority of the cooling capacity of the heat exchangers in the order of additional cooling heat exchanger (46, 46a, 46b, 46c), switchable air heat exchanger (10a) and outdoor air heat exchanger (10b).
22. A method according to claim 18, wherein the outside air heat exchanger (10b) is not traversed by air when there is no heat transfer there or only the heating tubes (12) are flowed through for the purpose of deicing.
23. The method of claim 18, wherein the refrigeration system (22) includes a plurality of parallel outdoor air heat exchangers (10b) that are mutually de-icing without interrupting the heating operation of the air heat exchanger (10a).
24. The method according to claim 18, wherein the refrigeration system (22) includes a plurality of parallel refrigerator-space heat exchangers (10a) that are mutually de-icing without interrupting the cooling operation of the other refrigerator-space heat exchanger (10a).
25. A method according to claim 18, wherein a common regulator via the control of the valves (28a, 28b, 52a, 52b, 52c, 52d, 52e, 52f, 58a, 58b) a predetermined overheating of the refrigerant at the low pressure side exit of the heat exchanger (70) and / / or at the input of the compressor (24) or a predetermined optimum high pressure or a predetermined supercooling of the refrigerant at the high pressure side input of the heat exchanger (70) controls.

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