EP4688471A1

EP4688471A1 - Apparatus for temperature-controlling a space, gas-liquid heat exchanger, and truck

Info

Publication number: EP4688471A1
Application number: EP24716139.1A
Authority: EP
Inventors: Jürgen Süss
Original assignee: Ecooltec Grosskopf GmbH
Current assignee: Ecooltec Grosskopf GmbH
Priority date: 2023-03-29
Filing date: 2024-03-27
Publication date: 2026-02-11
Also published as: WO2024200600A1; DE102023202885A1

Abstract

Apparatus for temperature-controlling, comprising: a gas-liquid heat exchanger (2) with a liquid side (2a); a first heat exchanger (8) arranged at least partially below the gas-liquid heat exchanger (2) and comprising a first primary side (8b) and a first secondary side (8a); a second heat exchanger (6) arranged at least partially higher than the gas-liquid heat exchanger (2) and comprising a second primary side (6b) and a second secondary side (6a); and a heat transport apparatus (20) for supplying heat to the primary side (8b) of the first heat exchanger (8) and for dissipating heat from the primary side (6b) of the second heat exchanger (6), wherein the first secondary side (8a) of the first heat exchanger (8) and the second secondary side (6a) of the second heat exchanger (6) can be coupled to the liquid side (2a) of the gas-liquid heat exchanger (2).

Description

Apparatus for Temperature-Controlling a Space, Gas-Liquid Heat Exchanger, and Truck

Description

The present invention concerns temperature-controlling a space to be temperature- controlled and, in particular, refrigeration or heat generation and distribution in mobile or stationary refrigeration applications.

In particular, the present invention relates to methods and apparatuses for refrigeration or heat generation or distribution in mobile refrigeration applications or heating applications and can be used for road-bound motor vehicles or trailers or semi-trailers with a refrigeration structure or a heating structure, a rail-bound or sea-bound refrigerated or heated structure or container, or generally for spaces to be temperature-controlled in ventilation or air- conditioning applications, which are refrigerated or heated by means of a compression refrigeration machine, for example.

Furthermore, this invention can also be used in the field of comfort air conditioning in mobile applications such as buses or rail-bound passenger cars in rail transport. In principle, however, from a purely technical point of view is not necessary to restrict the invention to these fields, as the solutions described here can also be used to advantage in stationary applications.

The compression refrigeration machine is the most common design of refrigeration machines. This design uses the physical effect of evaporation heat when the aggregate state changes from liquid to gaseous or from gaseous to liquid. In a compression refrigeration machine, a refrigerant with suitable thermal dynamic properties is moved in a closed cycle. In this case, it undergoes the various changes of the aggregate state one after the other. The gaseous refrigerant is first compressed by a compressor. In the following heat exchanger (or heat exchanger) (condenser or heat sink of the process), it is condensed (liquefied) while releasing heat. Subsequently, the condensed refrigerant is expanded to the evaporation pressure via an expansion element, or, in the simplest case, a diaphragm, or a capillary tube, so as to reduce the pressure. In this process, it cools down. In the downstream second heat exchanger (or heat exchanger) (evaporator or heat source of the process), the refrigerant evaporates while absorbing heat at a low temperature (evaporation cooling). The heat absorbed in this process represents the coldness used by the refrigeration system. The heat flow absorbed is referred to as refrigerating capacity. The evaporator is therefore advantageously located directly in the refrigeration structure, in the refrigeration container or generally in the closed space to be cooled of the application so as to keep heat exchange losses to a minimum by bringing the refrigerated goods into direct contact with the heat source as much as possible. The cycle can now start again. The process must be kept going from the outside by supplying mechanical work (drive power) via the compressor. The refrigerant absorbs a heat output at a low temperature level and usually dissipates it to the surrounding area by suppling technical work at a higher temperature level. The identical process described is referred to as a heat pump process if the condenser heat emitted by the condenser of the system is to be used instead of the refrigerating capacity or energy supplied to the evaporator. In the present application, this results in the possibility of supplying energy in the form of heat for heating purposes to the described structure, or the closed interior space, of the application with a suitable process control and an arrangement of the components of the system. One of the ways to achieve this is to connect the pressure-side outlet of the compressor to the heat exchanger located in the closed structure in such a way that it heats up during operation of the structure. The remaining components then fulfill their function according to the described application process for refrigeration. The heat supply can also be used to achieve efficient defrosting of the heat exchanger in the closed space, which can be either time-controlled or demand- controlled.

The refrigerant cycle essentially consists of the following four components: compressor, condenser, expansion element, and evaporator. In a single-stage or multi-stage refrigeration system, a distinction is generally made between the high-pressure and the low- pressure side. The high-pressure side extends from the pressure side of the compressor to the inlet of the refrigerant into the expansion element. The low-pressure side comprises the part of the refrigerant cycle from the outlet of the refrigerant out of the expansion element to the compressor inlet. This also applies if the refrigerant cycle is operated as a heat pump, i.e. the heat output provided by the condenser is used instead of the refrigerating capacity of the evaporator. As described, the heat output can be used to heat up the application or to defrost the evaporator.

Regardless of the application, the refrigerant used in the circular process in the cycle should have as little impact on the environment as possible, be cost-effective and particularly energy-efficient. A key measure of the environmentally harmful effect of a refrigerant is its global warming potential (GWP). This value is given for refrigerants in relation to the GWP value of CO2 (carbon dioxide). By definition, CO2 has a GWP value of 1 . For the F-gases (or fluorinates gases) frequently used as refrigerants, the global warming potential can have values of several thousand. This in turn means that one kilogram of F-gas released into the atmosphere during its production, use, or disposal can be equivalent to the greenhouse effect of several tons of CO₂.

The most important components of F-gases are carbon, hydrogen, and fluorine. F-gases often decompose very slowly and, once released, sometimes remain in our atmosphere for hundreds or several thousand years. Regardless of their residence time and the level of global warming potential, decomposition products are formed when F-gases decompose. These substances, such as trifluoroacetic acid or hydrogen fluoride, often have long-term negative effects on humans and the environment. For these reasons, international legislation is increasingly restricting or even prohibiting the use of F-gases as refrigerants by means regulations and ordinances. The acceptance of the F-gases as refrigerants by consumers and users of refrigeration technology, but also by society as a whole, is decreasing, and as a result, the refrigeration and heat pump manufacturing industry is increasingly demanding alternatives to the existing refrigeration technology based on the use of F-gases.

The object of the present invention is to provide an improved concept for temperature controlling a space to be temperature-controlled. This object is solved by an apparatus according to claim 1 , a gas-liquid heat exchanger according to claim 17, or a truck, a trailer, or a towed vehicle according to claim 21 .

An apparatus for temperature-controlling a space includes a gas-liquid heat exchanger with a liquid side as well as a first heat exchanger and a second heat exchanger, wherein the first heat exchanger is arranged at least partially below the gas-liquid heat exchanger, and the second heat exchanger is arranged at least partially higher than the gas-liquid heat exchanger. Both heat exchangers include a primary side and a secondary side, wherein the secondary sides of the two heat exchangers can be coupled to the liquid side of the gasliquid heat exchanger. Furthermore, a heat transport apparatus is provided to bring heat to the primary side of the first heat exchanger or to dissipate heat from the primary side of the second heat exchanger.

Due to the arrangement of the heat exchangers on the one hand and the gas-liquid heat exchanger on the other hand, temperature-controlling may be achieved with the gas-liquid heat exchanger by means of a natural circulation. According to the invention, the natural circulation process or thermosiphon process is used according to the state of the heat transport apparatus for both refrigerating and heating with the gas-liquid heat exchanger. Special pumps are not required to drive a fluid in its liquid form or vapor through the two heat exchangers and the gas-liquid heat exchanger, or to influence the same. A circulation direction is achieved solely due to the activation of the heat transport apparatus for supplying heat or for dissipating heat to or from the respective heat exchanger. Preferably, the gas-liquid heat exchanger is arranged in a space, preferably in the cargo space of a truck, so as to cool the cargo space. Then, the main activity of the apparatus for temperature-controlling the space will be to cool the space, and heating the space takes place only intermittently or as required to defrost the gas-liquid heat exchanger in the space so as to therefore set the same again in an operation state in which cooling the space may function more efficiently.

Depending on the implementation, the two secondary sides of the two heat exchangers are connected directly, which is of particular advantage if there is just a single gas-liquid heat exchanger in a space to be cooled or in a space to be temperature-controlled.

However, if several spaces to be temperature-controlled are connected to a single heat transport apparatus, the first and second heat exchangers are not directly connected with respect to their secondary side, but the heat exchangers can be coupled selectively to the gas-liquid heat exchangers by corresponding valves, which are typically provided in different spaces to be temperature-controlled in which different temperatures are to be generated.

The first heat exchanger arranged at least partially below the several gas-liquid heat exchangers is used to heat a space or a gas-liquid heat exchanger or to supply energy to the same, while the second heat exchanger is connected to a different gas-liquid heat exchanger arranged in the space to be temperature-controlled so as to carry out refrigeration there. Through this, e.g., the heat dissipated from the space during refrigeration may be used to heat the other space.

Preferably, however, the two heat exchangers are served by one and the same refrigerating cycle or heat pump cycle, comprising a compressor and an expansion element and which may additionally comprise a separate evaporator or condenser. Depending on the implementation, however, the corresponding heat exchanger or the primary side of the same may each be used as a condenser and/or an evaporator. To carry out switching accordingly as required, a controller that carries out, depending on the implementation, in particular when only a single gas-liquid heat exchanger is provided, corresponding controls so as to couple corresponding elements to each other or not is provided. However, if refrigeration with several separate refrigeration spaces is required, the refrigerating cycle may be firmly coupled to the heat exchangers, and temperature-controlling the space is carried out accordingly only due to the valves for coupling or decoupling the different gasliquid heat exchangers in the different spaces to be temperature-controlled with different temperatures.

Preferably, the refrigerating cycle and the primary heat pump cycle arranged outside of the space to be temperature-controlled, i.e. in the surrounding area of the space to be temperature-controlled, are configured to use a natural primary working fluid having properties that are unfavorable for a closed space, such as flammability. However, a different secondary fluid that is typically not harmful for an organism or has little risk since it is not flammable, for example, is used in a secondary circuit. Thus, primary working fluids and secondary fluids comprising suitable properties for a compression cycle or primary heat pump cycle on the one hand and for temperature-controlling a closed space to be temperature-controlled on the other hand may be combined.

In particular, the use of flammable primary working fluids as an example of a natural refrigerant, e.g. from the group of hydrocarbons, enables high environmental compatibility and energy-efficient properties in a com pression refrigeration/heat cycle. On the other hand, such refrigerants may be used in closed spaces usually only with significant additional effort due to their flammability. For example, such refrigerants are hydrocarbons (HC) such as propane (R290) or propene (R1270). Other fluorinated gas-free primary working fluids include NH₃ or NH₃/DME (R723), which are only slightly flammable but are toxic in closed spaces for the human organism and are therefore not desired. This group of substances for refrigeration also includes fluorinated hydrocarbons that are flammable due to their molecular composition.

On the other hand, non-flammable and therefore risk-free refrigeration/heat carrier media that ideally undergo a change of phase in the transport of cold or heat can be used in the secondary circuit, which is not used for refrigeration or heat generation but only for cold/heat distribution. A secondary fluid that changes its aggregate state in the transport of heat is preferably used is. In this case, heat is absorbed, or is dissipated, at a constant temperature, and the thermosiphon principle or natural circulation principle is driven in both directions, i.e. when refrigerating and when heating, due to the difference in density between vapor and liquid.

Preferably, the gas-liquid heat exchanger is configured as an end wall (or front wall) evaporator in the cargo space of a truck, wherein the gas-liquid heat exchanger includes a first collector pipe comprising a first port, and a second collector pipe comprising a second port, wherein the two ports are connected to each other by a plurality of line tubes between the first collector pipe and the second collector pipe so as to guide liquid or vapor of the liquid from the first port to the second port. In particular, refrigeration elements with thermally conductive ribs are attached to the line tubes so as to form gas channels between the ribs, with said gas channels extending towards the line tubes between the first collector pipe and the second collector pipe.

This gas-liquid heat exchanger configured as an end wall evaporator has a particularly high efficiency, in particular for the functionality in which refrigeration and heating, mostly used for defrosting, are used with the double thermosiphon principle, which does not use a pump for refrigeration or heating.

Preferably, the end wall evaporator is housed in a truck and in particular in the cargo space of a truck, wherein the heat supply apparatus is essentially housed in a recess above the structure behind the driver's cab, since this achieves short connections between the heat supply apparatus on the one hand and the gas-liquid heat exchanger on the other hand.

Embodiments of the present invention are advantageous as they provide a concept that is improved with respect to environmental issues for temperature-controlling a space to the temperature-controlled.

Preferred embodiments of the present invention are subsequently described with reference to the accompanying drawings in more detail, in which:

Fig. 1 shows a block-circuit diagram of an inventive apparatus for temperaturecontrolling;

Fig. 2 shows a preferred embodiment of the heat transport apparatus for the use of a gas-liquid heat exchanger for refrigeration and for heating; Fig. 3 shows a schematic illustration of the heat flow for cooling the space;

Fig. 4 shows a schematic illustration of the heat flow for heating the space;

Fig. 5 shows a schematic embodiment of the present invention in which the heat transport apparatus is configured for supplying heat;

Fig. 6 shows a schematic illustration of the present invention in which the heat transport apparatus is configured for dissipating heat;

Fig. 7 shows a schematic illustration of the present invention in which the heat transport apparatus is configured for supplying heat for the purpose of heating the space;

Fig. 8a shows a schematic illustration of the present invention for operating several gas-liquid heat exchangers with different valves and heat exchangers arranged in different cycles;

Fig. 8b shows an alternative implementation of the valve ports at one or several gasliquid heat exchangers;

Fig. 8c shows, in comparison to Fig. 8a, a schematic illustration of the present invention with several gas-liquid heat exchangers and an additional evaporator in addition to the optional condenser in Fig. 8a;

Fig. 9 shows a front view of the end wall evaporator and a lateral sectional view;

Fig. 10a shows a schematic view of the end wall evaporator in the cargo space of a truck in an isometric illustration;

Fig. 10b shows a section through the end wall evaporator;

Fig. 10c shows a detailed view of the ribs at the line tubes; Fig. 1 1 shows different detailed views and overall views of the end wall evaporator; and

Fig. 12 shows a schematic illustration of the truck with a heat transport apparatus in a recess of the structure.

Fig. 1 shows an apparatus for temperature-controlling with a gas-liquid heat exchanger 2 comprising a liquid side 2a. The air side, or so-called “air register," is formed by the arrangement and internal construction of the gas-liquid heat exchanger. The gas-liquid heat exchanger 4 is coupled via a pipeline to a first heat exchanger 8 arranged at least partially below the gas-liquid heat exchanger and comprising a primary side 8b and a secondary side 8a. Furthermore, a second heat exchanger 6 arranged at least partially higher than the gas-liquid heat exchanger is provided, wherein the second heat exchanger comprises a second secondary side 6a and a second primary side 6b.

In addition, a heat transport apparatus 20 is provided. The heat transport apparatus 20 functions for supplying heat to the primary side 8b of the first heat exchanger and for dissipating heat from the primary side 6b of the second heat exchanger. In particular, the first secondary side 6a of the first heat exchanger 8 and the second secondary side 6a of the second heat exchanger 6 can be coupled to the liquid side 2a of the gas-liquid heat exchanger 2. In the embodiment shown in Fig. 1 , this coupling is configured so as to be fixed, i.e. without a controllable variation. Depending on the requirement, this coupling may also be carried out selectively, i.e. controllably, which will be described on the basis of Figs. 8a to 8c, for example. In addition, in Fig. 1 , the coupling of the secondary side 8a, 6a of the heat exchangers is also configured so as to be fixed.

This coupling can also be configured so as to be controllable or it even may be implemented such that the two heat exchangers, as can be seen for example in Figs. 8a to 8c, are not connected in series, but are arranged in different cycles for heating a space with a first gasliquid heat exchanger and for cooling a further space with a second gas-liquid heat exchanger. In such an implementation, the two secondary sides of the heat exchanger 6 and 8 are not connected to each other but they are in different cycles so that both heat exchangers are in operation, whereas, in the implementation shown in Fig. 1 or Figs. 3 to 7, only one heat exchanger experiences flow-through and the other heat exchanger is active, either for supplying heat or for dissipating heat from the respective primary side. The heat transport apparatus 20 can be configured in any way to fulfil the corresponding function, i.e. supplying heat to the primary side of the first heat exchanger or dissipating heat from the primary side of the second heat exchanger. Preferably, the heat transport apparatus comprises a refrigerating cycle, as illustrated in Fig. 2. In Fig. 2, the refrigerating cycle consists of an evaporator 1 1 , a compressor 7a, a condenser 12, and an expansion element 7b. In addition, further elements that may be used for selectively supplying heat to the primary side of the first heat exchanger or for selectively dissipating heat from the primary side of the second heat exchanger are provided in the heat transport apparatus in Fig. 2. These are a first fluid switching element 10a and a second fluid switching element 10b as well as a first bypass 13 around the evaporator 11 and a second bypass 14 around the condenser 12. Furthermore, the two fluid switches 10a, 10b and the two bypasses 13, 14 are preferably driven by a controller 15 so as to supply the gas-liquid heat exchanger with energy or to gather energy from the same, depending on necessity or operation state.

Preferably, the gas-liquid heat exchanger 2 is arranged in a space 1 to be temperature- controlled by means of the apparatus. In order to cool this space, the fluid switch 10a is set to be active so that the primary side 6b of the second heat exchanger 6 is addressed by the heat transport apparatus. Preferably, in this case, the bypass 13 is inactive as well so that the block referred to as evaporator 1 1 in Fig. 2 is bypassed, since the actual evaporation effect takes place in the second heat exchanger 6 itself. In addition, the second fluid switch 10b is switched so as to be inactive so that no compressed vapor enters into the first heat exchanger 8 but is short-circuited in the fluid switch, i.e. from the upper to the lower exit. Furthermore, the bypass 14 is inactive as well so that the block 12 in Fig. 2 referred to as condenser acts as a condenser.

However, if the space is to be heated, or if the gas-liquid heat exchanger is to be supplied with heat by the heat transport apparatus, the fluid switch 10a is switched so as to be inactive, i.e. the left upper and the left lower exits are connected to each other so that vapor cannot enter the second heat exchanger 6 via the primary side 6b. On the other hand, the fluid switch 10b is active so that the first heat exchanger is addressed, i.e. obtains compressed hot vapor at its primary side 8b. In addition, the bypass 13 may be switched so as to be inactive so that the evaporator 11 actually functions as an evaporator of the refrigerating cycle. On the other hand, the bypass 14 is active so as to bypass the block referred to with condenser 12, since the first heat exchanger 8 will already function as a condenser of the refrigerating cycle in this case. Subsequently, further aspects of the present invention are described with reference to Figs.

3 to 7.

Figs. 3 to 7 illustrate the natural circulation for cooling or heating a closed space 1 , for example. The heat exchanger 2 having fluid therein is arranged in the closed space 1 . This fluid has a vapor pressure curve present as a two-phase fluid at the temperature to be set in the space. This fluid is preferably non-toxic and non-flammable so that there is no danger in the closed space 1 in the case of a leak. For example, such a fluid is carbon dioxide.

The fluid is present as a liquid phase 3a in the lower area of the gas-liquid heat exchanger 2, and the vapor 3b that rises through evaporation by the heat exchanger 2 withdrawing heat from the space 1 is collected in the upper area of the heat exchanger 2. Thus, the heat exchanger 2 represents the heat source of the natural circulation process or thermosiphon cycle. The heat created is supplied to the heat sink 6 of the natural circulation process or thermosiphon cycle via the pipeline 4. This heat sink 6, which corresponds to the second heat exchanger 6 in Fig. 1 or Fig. 2, is arranged geodetically such that it is located at least partially above the heat exchanger 2 in the closed space 1 . By dissipating the heat flow GK, the vapor is condensed and the fluid gets back to the heat exchanger 2 through a line 5 in its condensed form via gravity.

Here, heat supply to or heat dissipation from the space 1 starts again, therefore the process starts again, by the liquid phase of the fluid 3a evaporating through heat supply and the gaseous phase 3b being supplied again to the second heat exchanger 6 via the pipeline 4. Through this, the thermosiphon circuit is closed and the fluid autonomously circulates in a counter-clockwise direction, as indicated by the arrow in Fig. 3. The physical principle causing the circulation is based on the change of phases of the fluid and the associated variation in density. The vapor that rises to the top and the liquid that flows downwards cause the autonomous or natural circulation in the thermosiphon circuit. Ideally, the vapor that rises in the heat exchanger 2 causes a pump effect that allows the fluid to circulate in the cycle. The filling level of the natural circulation process or thermosiphon cycle is selected such that the fluid in the liquid phase 3a wets the surface of the heat exchanger 2 as much as possible. This is schematically indicated by the filling level in Fig. 3.

Thus, in the process illustrated in Fig. 3, a heat flow GQ is continuously withdrawn from the space via the heat exchanger 2 in which the fluid evaporates with its liquid phase 3a. The heat absorbed by the fluid in the heat exchanger 2 is released again in the thermosiphon cycle in the heat exchanger 6 representing the heat sink. When cooling the space illustrated in Fig. 3, the first heat exchanger 8 is adiabatic at first, i.e. heat is neither supplied nor dissipated by the same in the cycle. In contrast, the second heat exchanger 6 condenses vapor by heat dissipation. The heat exchanger 2 evaporates the liquid 3a and therefore cools the closed space 1 . Thus, the evaporated liquid 3a provides for the circulation of the fluid in a counter-clockwise direction in Fig. 3. This cycle is maintained as long as the heat flow QK is withdrawn from the heat exchanger 6 by the heat transport apparatus 20.

In Fig. 4 or Fig. 5, a heat flow QH is now supplied to the heat exchanger 8, i.e. the first heat exchanger. The heat exchanger 6 in Fig. 5 is adiabatic only, i.e. heat is neither supplied to nor dissipated from the same. Thus, the heat exchanger 6 is omitted in Fig. 4. Due to the heat supply in the first heat exchanger 8, there is an evaporation of the fluid, and the vapor rising provides for a circulation in the clockwise direction, which is why liquid fluid continuously enters the heat exchanger 8 through the connection line from the heat exchanger 2 and is supplied in its vaporous form from the heat exchanger 2 through the pipeline. This circuit is maintained as long as the heat flow QH is supplied to the heat exchanger 8.

The natural circulations described above are therefore able to temperature-control a space by either supplying or dissipating heat. In addition, and as mentioned above, a nonflammable and otherwise harmless fluid is used, ruling out that a flammable or otherwise dangerous atmosphere can be created in the closed space in the case of leakage of a fluid.

The supply and dissipation of a heat flow into the heat exchangers 6 and 8 described can be advantageously realized so that they are thermally connected to the evaporator or condenser of a refrigerating cycle 9. This arrangement is illustrated in Figs. 6 and 7, respectively. In Fig. 6, the second, or cold, heat exchanger 6 is connected to the evaporator of the refrigerating cycle and is therefore connected to the heat transport apparatus such that the heat exchanger 6 represents the evaporator of the refrigerating cycle 9. In Fig. 7, the first heat exchanger 8, i.e. the “lower” heat exchanger, is connected to the condenser of the refrigerating cycle, or is configured as the condenser of the refrigerating cycle.

A refrigerating cycle 9 consists of a compressor 7a compressing the vaporous refrigerant to a higher pressure level. The heat created and the heat absorbed previously in the form of refrigerating capacity is dissipated in the form of a condenser capacity QH by the refrigerating cycle. Subsequently, the condensed refrigerant is expanded in an expansion element 7b to the low pressure of the process. Now, there is the possibility to absorb the heat flow QK at a low temperature, typically below the ambient temperature. The vapor of the refrigerant created thereby is drawn in again by the compressor 7a and the refrigerating cycle is closed, or starts anew.

For energy efficiency and environmental reasons, a type of hydrocarbon is usually used as the refrigerant in a refrigerating cycle, which has a high energetic process efficiency and only a negligible negative effect on the environment, however, which has application risks in that a flammable mixture could be formed when the refrigerant exits a closed space due to leakage. Thus, according to the invention, it is preferred that the refrigerating cycle with a flammable refrigerant is coupled to the natural circulation that comprises another type of or a harmless refrigerant.

Fig. 6 illustrates how the evaporator or the refrigerating cycle 9 is coupled to the heat exchanger 6 of the natural circulation. The evaporator of the refrigerating cycle withdraws from the natural circulation the heat flow QK providing for the condensation at the fluid in the natural circulation. By dissipating the heat flow QK at the heat exchanger 6, the fluid will circulate in a counter-clockwise direction. In this case, as previously described, the heat flow QK is withdrawn from the closed space 1 by the liquid fluid 3a being evaporated in the heat exchanger 2 and by the same being supplied through the connection line 4 in the vaporous state 3b to the heat exchanger 6 where it is again supplied by the pipeline 5 to the heat exchanger 2 in the cycle.

The heat flow QK absorbed by the refrigerating cycle 9 is therefore withdrawn from the closed space 1 by means of the natural circulation cycle, without the risk that the flammable refrigerant of the refrigerating cycle 9 enters the closed space and therefore without the risk of formation of a flammable atmosphere. Ideally, the fluid in the natural circulation process has as a material property a higher vapor pressure than the refrigerant of the refrigerating cycle so that in case of a leak in one of the heat exchangers 6 or 8 the flammable refrigerant never enters the natural circulation cycle. For example, the inevitably generated heat flow QH of the refrigerating cycle is dissipated to the surrounding area and is not further used in this case.

In Fig. 7, the refrigerating cycle is now connected to the natural circulation cycle in such a form that the condenser of the refrigerating cycle now dissipates a heat flow QH, i.e. the condensation capacity of the refrigerating cycle 9, to the heat exchanger 8 of the natural circulation cycle. In this case, the fluid located in the natural circulation is evaporated in the heat exchanger 8. The vapor that rises is now supplied to the heat exchanger 2 and the closed space 1 via the pipeline 4 and is condensed there. The liquid phase of the fluid 3a created there subsequently flows through the pipeline 5 into the heat exchanger 8 where the fluid is evaporated again due to the supply of the heat flow QH of the refrigerating cycle. The fluid now circulating in the natural circulation in the clockwise direction therefore transmits the condenser capacity of the refrigerating cycle via the heat exchanger 8 into the closed space. This circuit is maintained as long as a heat flow from the refrigerating cycle 9 is supplied to the heat exchanger 8. For example, the inevitably absorbed heat flow QK of the refrigerating cycle 9 is captured from the surrounding area in this case.

Figs. 8a to 8c show a preferred embodiment of the present invention in which, in contrast to Figs. 1 to 7, the two secondary sides of the heat exchangers 6, 8 are not directly coupled to each other. However, both secondary sides of the heat exchanger can each be coupled to a heat exchanger 2 or 22a. To this end, a controllable valve apparatus that includes the valves 16a, 16b for the second heat exchanger 6 and the valves 18a and 18b for the first heat exchanger 8 is provided. In addition, for the further heat exchanger 22a in another space to be temperature-controlled, the two valves 18c and 18d are provided again for the first heat exchanger 8, and the two valves 16c and 16d for the second heat exchanger 6.

Fig. 8b shows an implementation in which the valves 16a, 81 a, same as the valves 16b, 18b, are connected to the heat exchanger 2 at their side facing the heat exchanger 2 only via one port. Alternatively, the valves 16a, 18a, 16b, 18b are each connected individually to the heat exchanger 2 and in particular to the respective collector pipe of the heat exchanger 2.

In addition, Figs. 8a and 8b shows the provision of an optional separate condenser 12 in addition to the heat exchanger 8, while Fig. 8c further shows a second evaporator 11 in addition to the second heat exchanger 6. A condenser 12 may be required if, in case of two areas or spaces to be temperature-controlled, one can usually not assume that one space has to be heated up to the same extent that the other space is cooled down. However, e.g., if one refrigeration space shall be used to heat two heated spaces, the condenser is possibly not required, since the entire “refrigeration heat” is consumed for heating the two spaces to be heated. However, a separate condenser 12 may be required in the heat transport apparatus so as to transport to the surrounding area the energy that is obtained by cooling a space and that cannot be used for heating another space. Fig. 8c further shows the provision of a separate evaporator 1 1 . The separate evaporator 11 would be required if the energy withdrawn by cooling a space is not sufficient to cool the one or the several other spaces.

Figs. 8a to 8c shows the case in which the refrigerating cycle 9 is simultaneously connected to two independent autonomous circulation cycles, each including the heat exchanger 6 and 8. To this end, the evaporator of the refrigerating cycle is connected to the heat exchanger 6 for cooling the several closed spaces, i.e. to the heat exchangers 2 and 22a, respectively, in the closed spaces 1 and 1 a via the valves 16a, 16b, 16c, and 16d. If the valves 16a, 16b 16c, 16d are subsequently opened, the refrigeration capacity generated in the evaporator is withdrawn from the heat exchanger 6, and the same is split onto the heat exchanger 2 and 22a which then cool the spaces 1 and 1 a, respectively. The condenser of the refrigerating cycle is thermally connected to the heat exchanger 8 and supplies the same with a heat flow. The heat exchanger 8 is also part of the pipeline network connected to the heat exchanger 2 and 22a, respectively, via the valves 18a, 18b, 18c, and 18d. The heat exchangers mentioned are located in the space 1 and space 1 a, respectively. If the valves 18a, 18b, 18c, and 18d are opened, there is the possibility to heat the closed space 1 and the closed space 1 a, respectively, i.e. to supply part of the heat flow that was previously transmitted in the heat exchanger 8 of the natural circulation cycle for heating the closed spaces.

Ideally, the fluids in the respective natural circulation process have as a material property a higher vapor pressure than the refrigerant of the refrigerating cycle, so that, even in the case of a leak in one of the heat exchangers 6 or 8, the flammable refrigerant could never enter one of the natural circulation cycles. The fluids in both natural circulation processes may be identical.

In addition, it is preferred to heat or cool the spaces 1 and 1 a, respectively, due to switching the valves 16a to 16d and the 18a to 18d, respectively, in the illustrated case in Figs. 8a to 8c, by supplying or dissipating a heat flow. In this case, by accordingly switching the valves 16a to 16d and 18a to 18d, respectively, it is possible to withdraw heat from the space 1 , while heat is simultaneously supplied to the space 1. For example, if the space 1 is to be cooled, i.e. heat is to be withdrawn from the same, this is done by opening the valve 16a and 16b simultaneously or in a temporally offset fashion, while keeping the valves 18a and 18b closed. Thus, the closed space 1 is cooled, as previously described, by withdrawing heat from the heat exchanger 6, with said heat then being withdrawn from the space 1 by the natural circulation via the heat exchanger 2.

However, if the space 1 is to be heated, i.e. heat is to be supplied to the same, the valves 6a and 6b are kept closed, while the valves 18a and 18b are opened simultaneously or in a temporally offset fashion so as to connect, by means of the natural circulation cycle, the heat exchanger 2 to the heat exchanger 8 which in turn absorbs the condensation heat of the refrigerating cycle. The same applies for heating or cooling the space 1 a, by accordingly switching the valves 16c and 16d or 18c and 18d, respectively.

In this way, any number of spaces to be temperature-controlled can be connected in autonomous circulation with only one single refrigerating cycle, as is schematically illustrated in Figs. 8a to 8c, when further spaces, not illustrated in Figs. 8a to 8c, are connected.

Due to the thermostatic regulation of the valve in the feed/return of the natural circulation cycles, different temperatures can be realized in each space to temperature-controlled. In this case, the temperature in the cold natural circulation cycle may be below and the temperature in the warm natural circulation cycle may be above the respectively targeted temperature to be set in each space to be temperature-controlled. Thus, the temperatures in each space may be freely selected and controlled between the lowest and highest temperature in the two natural circulation cycles for cooling and heating, respectively. Reaching the targeted temperature to be set is then carried out only via the amounts of fluid fed to and dissipated from the respective heat exchangers 2 and 22a in the closed spaces 1 and 1 a and all further spaces possibly available.

All heat exchangers in all different spaces may also be used to heat all spaces or cool all spaces. The heat exchanger 2, 22a may also be arranged at different positions in one space so as to generate different temperature zones without having to insulate the spaces from each other.

In addition to its heat source in the heat exchanger 6 and its heat sink in the heat exchanger 8, the refrigerating cycle 9 contained in the heat transport apparatus may, but does not have to, comprise heat exchangers or condensers and evaporators 1 1 , 12 for further heat absorption or heat dissipation, which may become necessary if the fixed-ratio refrigeration capacity and heat capacity generated by the refrigerating cycle do not match the demand of the thermosiphon or natural circulation cycle. In this case, it is possible that the refrigerating cycle absorbs additional heat from a heat source on the low-pressure or low- temperature side, or dissipates heat at its heat sink to the high-pressure or high-temperature side of its cycle. The heat source of the refrigerating cycle on the low-pressure side is the evaporator 11 in Fig. 2 and Fig. 8c, and the heat sink on the high-pressure side of the refrigerating cycle is the evaporator 12 in Figs. 8a to 8c, and Fig. 2.

The gas-liquid heat exchanger, as exemplarily shown in Fig. 1 and other figures and preferably not exclusively used for temperature-controlling, includes a first collector pipe 31 , a second collector pipe 32, and a plurality of line tubes attached between the first collector pipe 31 and the second collector pipe 32 in a fluidic parallel connection, as shown in Fig. 1 at 33.

In particular, the first collector pipe 31 is provided with a first exit 31 a. In addition, the second collector pipe 32 is connected to a second exit 32a. The individual line tubes are soldered or welded to the first and second collector pipes 31 , 32, achieving a liquid-tight and vapor- tight connection. The openings 31 a, 32a of the collector pipes represent the upper port 31 a and the lower port 32a of the gas-liquid heat exchanger, preferably used as an end wall evaporator in a space to be cooled, which is the cargo space of a truck, for example. All the way on its left side, Fig. 9 shows a top view of an end wall evaporator without an end wall. On the other hand, the left side of the middle image of Fig. 9 shows an end wall 33 comprising air suction openings 34. The right partial image on the left side of Fig. 9 shows a view of the area that shows only the lower supports 35 as an impact protection for the cargo. Fig. 9 shows in the right image a section along the line C-C of Fig. 9, left side. An air blower 36 and a cold air blowing apparatus 37 are shown as well, which is also shown in Fig. 9 on the left side. The blower 36 is configured to draw in air from the bottom to the top. Through this, the air is drawn through the air suction openings 34 from the lower region, i.e. where the air suction openings 34 are arranged, behind the end wall 33 so as to flow from the bottom to the top typically on both sides of the plurality of line tubes 33 so as to be cooled on this way. The cold air is then blown out of the cold air blowing apparatus 37 essentially in an angle of 90°, said apparatus typically having a flat shape so as to blow out essentially uniformly across the width of the truck.

Fig. 10 shows an isometric view of the top view of Fig. 9 with the end wall evaporator including the end wall 33, the suction openings 34, and the blowing apparatus 37. Furthermore, Fig. 10 shows a recess 40 attached in the upper area of the trailer of a truck, i.e. in particular behind the driver’s cab, in which the external device, i.e. the external refrigerating cycle, is housed. Fig. 10 shows a detailed view of the end wall evaporator, i.e. in particular of the first collector pipe 31 having attached thereto the individual line tubes 33. Furthermore, cooling elements 35 used to increase the surface of the line tubes are applied to every two adjacent line tubes 33. Thus, the heat transmission efficiency from gas to liquid or vice versa from liquid to gas is increased since the thermally effective surface area is significantly increased.

Preferably, the cooling element 35 has ribs 35a, with gas channels extending towards the line tubes 33 between the first collector pipe 31 and second collector pipe 32 being present between the ribs 35a. It is to be noted that the cooling elements 35 in Fig. 10c can be exemplarily configured as partially illustrated in Fig. 1 1. In particular, Fig. 11 shows on its left side a top view and on its right side an isometric view of the gas-liquid heat exchanger with the two collector pipes 31 , 32 and the line tubes arranged therebetween and being covered in both the views by the cooling elements 35. An exemplary cooling element is shown in the center of Fig. 11 at 35. Fig. 1 1 further shows a fastening rail 36a approximately in the center of the cooling element, and an upper fastening rail 36b and a lower fastening rail 36c. Furthermore, this fastening rail 36a is also shown in the sectional view in the upper center of Fig. 1 1 , wherein one cooling element each is screwed to the rail 36a by a screw 30 or 37b, respectively. The heat tubes 33 are also shown in Fig. 11 .

Fig. 12 shows a schematic view of a truck with a refrigeration unit 41 housed in the recess 40 described in Fig. 10a.

In particular, the housing 41 , i.e. the upper heating unit, includes all elements with a transport apparatus and additionally preferably the second heat exchanger 6 of Fig. 1. In contrast, the heat exchanger 8 of Fig. 1 is arranged in a region outside of the cargo space, however, below the end wall evaporator, i.e. preferably in a recess, not shown in Fig. 12, at the bottom of the structure of the truck. Since the first heat exchanger 8 does not require any connection to the outside, but only has to be housed in its operation direction below the end wall evaporator 2 so as to maintain the thermosiphon cycle, as described above, and therefore does not need any ports towards the outside, little effort is needed to house this heat exchanger. However, it is preferred to house the heat exchanger in a space that is insulated from the cargo space so that the refrigerant of the outer cycle cannot enter the cargo space. In the embodiment shown in Fig. 11 , a cooling element 35 includes a total of ten ribs. In contrast, in the embodiment of Fig. 10c, a cooling element includes eleven ribs. Preferably, the number of ribs per cooling element will be between five and twenty, which also depends on the number of the connected pipes. Furthermore, it is possible to arrange the cooling elements on both sides of the pipes so as to further increase the air-side surface area. In addition, the diameter of the upper collector pipe is set to be similar to the diameter of the lower collector pipe, wherein the lower liquid-carrying pipe has a smaller diameter than the upper vapor-carrying pipe so as to keep the entire filling amount of the system as low as possible. The diameter of the individual line tubes is accordingly set to be smaller so that the added surface area of the diameters of the individual line tubes is equal to the opening surface area of the upper collector pipe 31 and the lower collector pipe 33, respectively, in the embodiment. However, the cross sectional area of the upper and lower collector pipes may also be slightly smaller than the added-up cross sectional areas of the individual line tubes, wherein the minimum cross sectional area of the upper/lower collector pipe 31 , 32 is preferably at least half of the added-up cross sectional area of the individual line tubes. The lower collector pipe 33 should comprise a smaller diameter than the upper collector pipe 31 so as to keep the specific volume of the refrigerant filling as large as possible, i.e. to have little filling per volume so as to be able to also limit the pressures occurring at high temperatures.

Furthermore, the two collector pipes 31 , 32 and the line tubes 33 are made of copper so as to have good heat conductivity. In addition, the individual cooling elements are configured with the ribs 35a made of aluminum. The diameter of a line tube should be between 1 mm and 10 mm and preferably between 4 mm and 6 mm and most preferably 5 mm.

In the following, further preferred embodiments and additions to the previous embodiments are described.

Conventionally, heat exchangers of refrigeration systems have a refrigerant flowing through the same, with said refrigerant being pumped by a machine, typically a condenser, in circulation. Thus, there is typically a pressure difference across the component providing for the flow-through of the same. Particularly, if there are several parallel passages for the refrigerant through the heat exchanger, there may be an irregular distribution of the refrigerant through the passages. This results in the fact that the heat exchanger, e.g. configured as an evaporator, is not utilized in the best possible way due to the fact that the refrigerant tends to flow through the passages with the lowest flow resistance, i.e. where the creation of vapor does not obstruct the passage. This detrimental effect of an irregular distribution of the refrigerant is avoided by the invention described herein.

In the illustrated concept, perpendicular pipes connected at the bottom and the top to one collector pipe each are filled with a fluid that carries out a change of phase in the range of the desired evaporation temperature. The diameter of the perpendicular pipe should have a size that ensures that liquid refrigerant, or a fluid, wets the pipe inner wall across the entire height of the heat exchanger. This achieves that the satiation temperature of the refrigerant is applied across the entire pipe length, or the height of the heat transfer from the inside of the pipe.

When using CO2 as a working fluid or refrigerant, pipe diameters of between 2 mm and 6 mm have proven useful. In principle, this solution can also be realized with other diameters.

If the heat exchanger as described herein is operated as an evaporator, vapor that rises in the perpendicular pipes will lead to an autonomous or natural circulation of the refrigerant.

A particularly advantageous embodiment of the heat exchanger is the use of pressureresistant pipes with a small diameter for the pipes and the collector pipes at the respective ends. If air is to be cooled with the evaporator, it is particularly advantageous to increase the heat transmission area on the air-side. This can be achieved by connecting elements for increasing the surface area to the pipes in a thermally conductive way.

To facilitate the outflow of condensation water created when cooling humid air and to minimize pressure losses in the longitudinal direction of the heat exchanger, the elements for increasing the air-side surface area are exemplarily and advantageously configured as extrusion elements made of aluminum that are then connected in a thermally conductive way to the perpendicular pipes having applied thereto a refrigerant on their inside, as mentioned above.

The geometry of the elements used for increasing the surface area can be designed freely. It is also conceivable to connect in a thermally conductive way the perpendicular pipes of the heat exchanger to a smooth surface made of conductive material, such as aluminum, instead of the illustrated elements for increasing the surface area. This achieves that a surface applied to an insulated wall adopts the temperature of the evaporated refrigerant. If this wall is mounted in a refrigeration space, the surface of the sidewalls of the refrigeration space is cooled. This is a particularly suitable option for smaller refrigeration spaces, since, in this case, there is free convection only on the air side and the use of ventilators can be omitted.

Regardless of the elements for increasing the surface area of the air side, i.e. either the use of suitable geometries or the use of a plane wall, it is possible for the heat exchanger here adopting the function of an evaporator, as described, to be heated from the inside so as to defrost the same, i.e. to free it from ice, or to permanently use it for heating. Essentially, this may be achieved by two methods:

1 . For example, a pump that draws in the refrigerant from the heat exchanger against the natural circulation and that conveys the same to a heat sink located in the same cycle can be attached at the bottom collector pipe of the evaporator. This heat source increases the pressure and therefore also the temperature in the cycle. The refrigerant drawn out from the preferably perpendicular heat exchanger now exposes a surface area at which vaporous refrigerant now condenses and therefore dissipates the condensation heat to the inner side of the pipe, with said heat then being forwarded to the air-side surface increase connected in a thermally conductive way, and here providing for the increase in temperature. The use of the pump is advantageous if the heat source is located geodetically above the described transmitter with the perpendicular pipes.

2. The use may be avoided if the heat source is arranged below the described heat exchanger with the perpendicular pipes. This type of arrangement ensures that vapor is generated upon heat of the heat source being supplied, wherein said vapor is then condensed in the heat exchanger arranged geodetically above, and may here be used to heat up the component for defrosting or for permanently heating a space.

Regardless of the selection of the above-described variations, the heat exchanger with the perpendicular pipes may be used for cooling or heating with different forms of the surface increase.

The end wall evaporator is a preferred embodiment for a temperature-controlling element arranged preferably geodetically below the primary circuit, as described in the German patent application mentioned. A pump is preferably arranged so as to pump refrigerant around in the preferably perpendicular channels. Preferably, the temperature-controlling element is arranged at an end side of a truck as an example for a space to be temperature- controlled. Preferably, a blower is provided so as to move air past the temperaturecontrolling element in the space to be temperature-controlled. Furthermore, several temperature zones are provided in the space to the temperature-controlled, wherein a temperature-controlling element, such as the end wall evaporator, is provided for each temperature zone.

Even though some aspects have been described within the context of a device, it is understood that said aspects also represent a description of the corresponding method, so that a block or a structural component of a device is also to be understood as a corresponding method step or as a feature of a method step. By analogy therewith, aspects that have been described within the context of or as a method step also represent a description of a corresponding block or detail or feature of a corresponding device. Some or all of the method steps may be performed by a hardware device (or while using a hardware device), such as a microprocessor, a programmable computer or an electronic circuit. In some embodiments, some or several of the most important method steps m ay be performed by such a device.

The above-described embodiments merely represent an illustration of the principles of the present invention. It is understood that other persons skilled in the art will appreciate modifications and variations of the arrangements and details described herein. This is why it is intended that the invention be limited only by the scope of the following claims rather than by the specific details that have been presented herein by means of the description and the discussion of the embodiments.

A preferred embodiment of the end wall evaporator is to be arranged below the CO2 level. The evaporator is to be mounted vertically at a wall, wherein CO2 in its liquid phase enters into the lower head and leaves the same as vapor through the upper head. In the extrusion parts, no additional ribs should be present. The airflow also takes place from top to bottom. The temperatures on the CO2 side are in the range of between - 50 and + 20 °C. Ambient temperatures should not exceed 70 °C in the summer sun. A small groove or a groove with a drainpipe is preferably arranged at the bottom collector pipe so as to collect and dissipate condensed humidity. There should be heat conductivity between the bottom headpiece or collector pipe and the groove for possible defrosting.

Claims

1 . Apparatus for temperature-controlling, comprising: a gas-liquid heat exchanger (2) with a liquid side (2a); a first heat exchanger (8) arranged at least partially below the gas-liquid heat exchanger (2) and comprising a first primary side (8b) and a first secondary side (8a); a second heat exchanger (6) arranged at least partially higher than the gas-liquid heat exchanger (2) and comprising a second primary side (6b) and a second secondary side (6a); and a heat transport apparatus (20) for supplying heat to the primary side (8b) of the first heat exchanger (8) and for dissipating heat from the primary side (6b) of the second heat exchanger (6), wherein the first secondary side (8a) of the first heat exchanger (8) and the second secondary side (6a) of the second heat exchanger (6) can be coupled to the liquid side (2a) of the gas-liquid heat exchanger (2).

2. Apparatus according to claim 1 , wherein the gas-liquid heat exchanger (2) comprises an upper port (31 a) and a lower port (32a) forming the liquid side (2a), and wherein the upper port (31 a) is arranged in the operation direction above the lower port (32a), and wherein the lower port (32a) of the gas-liquid heat exchanger (2) can be connected to a first lower port of the first heat exchanger (8), and wherein the upper port (31 a) of the gas-liquid heat exchanger (2) can be connected to a second upper port of the second heat exchanger (6).

3. Apparatus according to claim 2, wherein a first upper port of the first heat exchanger (8) can be connected to a second lower port of the second heat exchanger (6), or wherein the first heat exchanger (8) is arranged in the operation direction below the second heat exchanger (6).

4. Apparatus according to any of the preceding claims, wherein the gas-liquid heat exchanger (2) can be mounted in a space (1 ), wherein the heat transport apparatus (20) is configured to supply heat of the space (1 ) to the primary side (8b) of the first heat exchanger (8) so as to evaporate liquid in the secondary side of the first heat exchanger in order to generate vapor, wherein the gas-liquid heat exchanger (2) is coupled to the second heat exchanger (6) such that, after having flown through the secondary side (6a) of the second heat exchanger (6), the vapor enters the gas-liquid heat exchanger (2) so as to be condensed in the gas-liquid heat exchanger (2), and wherein the gas-liquid heat exchanger is connected to the secondary side (8a) of the first heat exchanger (8) such that a liquid due to vapor evaporated in the gasliquid heat exchanger (2) is able to flow from the liquid side of the second gas-liquid heat exchanger into the secondary side (8a) of the heat exchanger (8).

5. Apparatus according to claim 4, wherein the second heat exchanger (6) is coupled to the first heat exchanger (8) such that the vapor flows through the secondary side of the second heat exchanger (6).

6. Apparatus according to any of the preceding claims, wherein the gas-liquid heat exchanger is arranged in a space (1 ), wherein the heat transport apparatus (20) is configured, for cooling the space, to dissipate heat from the first primary side (6b) of the second heat exchanger (6) so as to condense vapor in the second secondary side (6a) of the second heat exchanger, and wherein the secondary side (6a) of the second heat exchanger (6) is coupled to the gas-liquid heat exchanger such that the liquid from the first secondary side (8a) of the first heat exchanger (8) is able to enter the liquid side (2a) of the gas-liquid heat exchanger, and wherein the gas-liquid heat exchanger (2) is coupled to the second heat exchanger (6) such that vapor due to a liquid evaporated in the gas-liquid heat exchanger (2) is able to enter the second secondary side (6a) of the second heat exchanger (6).

7. Apparatus according to claim 6, wherein the second secondary side (6a) of the second heat exchanger (6) is coupled to the first secondary side (8a) of the first heat exchanger so that liquid due to condensed vapor is able to flow through the secondary side (8a) of the first heat exchanger (8).

8. Apparatus according to any of the preceding claims, wherein a cycle comprising the first heat exchanger (8) and the gas-liquid heat exchanger (2) on the one hand or the second heat exchanger (6) and the gas-liquid heat exchanger (2) on the other hand or the first heat exchanger (8), the second heat exchanger (6), and the gasliquid heat exchanger (2) does not have a pump, or wherein the first heat exchanger (8) or the second heat exchanger (6) is configured as a liquid heat exchanger or as a plate heat exchanger.

9. Apparatus according to any of the preceding claims, wherein the heat transport apparatus comprises a compressor (7a), a vaporizer (11 , 6), a condenser (12, 8), and a throttle (7b) arranged as a heat pump cycle, wherein the evaporator (1 1 ) is configured so as to be separated from the second heat exchanger (6) and is coupled to the primary side (6b) of the second heat exchanger, or is formed through the primary side of the second heat exchanger (6), or wherein the condenser (12) is configured so as to be separated from the first heat exchanger (8) and can be coupled to the primary side (8b) of the first heat exchanger (8) or is formed through the primary side (8b) of the first heat exchanger (8).

10. Apparatus according to any of the preceding claims, further comprising: a controller (15) for closing a first cycle with the first secondary side of the first heat exchanger and the liquid side of the gas-liquid heat exchanger (2), or a second cycle with the second secondary side (6a) of the second heat exchanger and the liquid side (2a) of the gas-liquid heat exchanger, wherein the controller (15) is configured to close the first cycle if heat is to be supplied to the primary side (8b) of the first heat exchanger (8) by the heat transport apparatus, or to close the second cycle if heat is to be dissipated from the primary side (6b) of the second heat exchanger (8) by the heat transport apparatus (20).

1 1. Apparatus according to claim 10, wherein the controller (15) comprises a controllable valve apparatus (16a-16d, 18a-18d) arranged between the gas-liquid heat exchanger (2) and the first heat exchanger (8) or between the gas-liquid heat exchanger (2) and the second heat exchanger (6).

12. Apparatus according to claim 11 , wherein the controllable valve apparatus comprises a first valve (18a) between an upper port of the first secondary side (8b) of the first heat exchanger (8) and an upper port (31 a) of the gas-liquid heat exchanger (2), and a second valve (18b) between a lower port (32a) of the first secondary side (8b) of the first heat exchanger (8) and a lower port (32a) of the liquid side of the gas-liquid heat exchanger, or wherein the controllable valve apparatus comprises a third valve (18c) between an upper port of the second secondary side of the second heat exchanger (6) and an upper port of the gas-liquid heat exchanger (2), and a fourth valve (16d) between a lower port of the second secondary side of the second heat exchanger (6) and a lower port of the liquid side of the gas-liquid heat exchanger (2).

13. Apparatus according to any of the preceding claims, further comprising: at least one further gas-liquid heat exchanger (1 a), wherein the at least one further gas-liquid heat exchanger comprises a further liquid side and is arranged at a different position than the gas-liquid heat exchanger (1 ).

14. Apparatus according to claim 13, further comprising: a controller (15) for selectively connecting the further liquid side of the at least one further gas-liquid heat exchanger (1 a) to the first heat exchanger (8) or the second heat exchanger (6), and for selectively connecting the liquid side of the gas-liquid heat exchanger (1 ) to the first heat exchanger (8) or the second heat exchanger (6).

15. Apparatus according to claim 14, wherein the controller (15) is configured to connect the liquid side (2a) of the gas-liquid heat exchanger (1 ) to the first heat exchanger (8) or the second heat exchanger (6), and to connect the further liquid side of the at least one further gas-liquid heat exchanger (1 a) to the respectively other heat exchanger of the first heat exchanger (8) and the second heat exchanger (6).

16. Apparatus according to claims 14 or 15, wherein the gas-liquid heat exchanger (1 ) is arranged in a first space and the at least one further gas-liquid heat exchanger (1 a) is arranged in a second space that is separated from the first space, or wherein the controller (15) is configured to control a flow-through in the liquid side through the gas-liquid heat exchanger or through the further gas-liquid heat exchanger so that different temperatures can be set in the first space and the second space.

17. Gas-liquid heat exchanger (2), comprising: a first collector pipe (31 ) comprising a first port (31 a); a second collector pipe (32) comprising a second port (32); and a plurality of line tubes (33) arranged between the first collector pipe (31 ) and the second collector pipe (32) in a fluidic parallel connection to connect to the first collector pipe and the second collector pipe so that the liquid or the vapor of the liquid is able to flow from the first port (31 a) to the second port (32a) or vice versa.

18. Gas-liquid heat exchanger according to claim 17, wherein cooling elements (35) with ribs (35a) are arranged at the line tubes (33) in a thermally conductive way so as to form gas channels between the ribs (35a), said gas channels extending towards the line tubes (33) between the first collector pipe (31 ) and the second collector pipe (32).

19. Gas-liquid heat exchanger according to claim 17 or 18, further comprising an end wall (33) attached to be aligned with respect to the line tubes (33) so that a gas flow can be formed between the line tubes (33) and the end wall (33a), wherein the end wall (33a) comprises gas entry openings (34) at a region, arranged downwards in the operation direction, of the end wall (33a), or is open at a lower end so that gas is able to enter behind the end wall and is able to flow from bottom to top.

20. Gas-liquid heat exchanger according to any of claims 17 to 19, further comprising: a blower (36) arranged at an upper end of the gas-liquid heat exchanger (2) in the operation direction to draw in gas from a rear area of the gas-liquid heat exchanger in the operation direction towards the upside and to eject the same above the gasliquid heat exchanger via an ejection apparatus (37) in an upper area in front of the gas-liquid heat exchanger, or wherein the plurality of line tubes (33) is arranged in a straight shape, wherein the line tubes connect the first collector pipe (31 ) and the second collector pipe (32) direct without any curves, or wherein the lower collector pipe (33) has a smaller diameter than the upper collector pipe (31 ).

21 . Truck, trailer, or towed vehicle, comprising: the apparatus according to any of claims 1 to 16, wherein the gas-liquid heat exchanger (2) is configured in a cargo space of the truck, trailer, or towed vehicle and wherein the first heat exchanger (6) and the second heat exchanger (8) and the heat transport apparatus (20) are arranged outside of the cargo space of the truck, trailer, or towed vehicle.

22. Truck, trailer, or towed vehicle according to claim 21 , wherein the cargo space is arranged in a structure, wherein the structure comprises at a front end arranged close to the driver’s cab of the truck, trailer, or towed vehicle a recess (40) in which the second heat exchanger and the heat transport apparatus (20) are arranged in a housing (41 ), wherein the housing (41 ) is configured and arranged such that housing walls and adjacent walls of the structure are essentially seamless with respect to each other, or wherein the first heat exchanger (8) is arranged in an area outside of the structure and below the gas-liquid heat exchanger (2).

23. Truck, trailer, or towed vehicle according to claim 21 or 22, wherein the gas-liquid heat exchanger according to any of claims 17 to 20 is configured to be arranged in the cargo space essentially vertically at an end wall of the cargo space.

24. T ruck, trailer, or towed vehicle according to claims 21 to 23, wherein the cargo space comprises two or several spaces (1 , 1 a) separated from each other, and wherein the apparatus for temperature-controlling according to any of claims 14 to 16 is configured, wherein the gas-liquid heat exchanger is arranged in a first space of the two separated spaces, and the at least one further gas-liquid heat exchanger (1 a) is arranged in a second space of the at least two or more separated spaces, and wherein the controller (15) is configured to drive the valve apparatus (16a-16c, 18a- 18d) such that the first space can be temperature-controlled with a first temperature, and a second space can be temperature-controlled with a second temperature, wherein the second temperature differs from the first temperature.

25. Truck, trailer, or towed vehicle according to claim 24, wherein the apparatus (15) is configured to connect the liquid side of the gas-liquid heat exchanger (2) to the second heat exchanger (6) so as to cool the space (1 ), and to connect the further liquid side of the further gas-liquid heat exchanger (1 a) to the first heat exchanger (8) so as to cool the further space (1 a).