US20240263851A1

US20240263851A1 - Method and apparatus for temperature-controlling a space to be temperature-controlled

Info

Publication number: US20240263851A1
Application number: US18/618,087
Authority: US
Inventors: Jürgen Süss
Original assignee: Ecooltec Grosskopf GmbH
Current assignee: Ecooltec Grosskopf GmbH
Priority date: 2021-09-30
Filing date: 2024-03-27
Publication date: 2024-08-08
Also published as: EP4314671B1; EP4314671A1; AU2022357257A1; WO2023052244A1; JP2024536336A

Abstract

Apparatus for temperature-controlling a space to be temperature-controlled with a space limitation separating the space to be temperature-controlled from a surrounding area, comprising: a primary heat pump circuit with an evaporator, a condenser, a compressor, and an expansion element, wherein the primary heat pump circuit comprises a natural such as a flammable, primary working fluid, wherein the evaporator, the liquefier, the compressor, and the expansion element are arranged outside of the space to be temperature-controlled; a secondary circuit thermally coupled to and fluidically decoupled from the evaporator or the condenser via a heat exchanger and comprising a temperature-controlling element arranged in the space to be temperature-controlled and connected to the heat exchanger via a line arrangement comprising a secondary fluid that differs from the primary working fluid, wherein the line arrangement penetrates the space limitation.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of copending International Application No. PCT/EP2022/076419, filed Sep. 22, 2022, which is incorporated herein by reference in its entirety, and additionally claims priority from German Applications Nos. DE 10 2021 211 049.5, filed Sep. 30, 2021 and DE 10 2022 201, filed Feb. 21, 2022, all of which are incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to temperature-controlling a space to be temperature-controlled and in particular to 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, as shown in FIG. 2 a . 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 1. In the following heat exchanger (or heat transmitter) 2 (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 3, 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 4 (or heat transmitter) (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 5 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 has to 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, as shown in FIG. 2 b , 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 1, condenser 2, expansion element 3, and evaporator 4. 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, CO₂has 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.
DE 202022100810 U1 shows a heat pump system with a heat pump, a consumer circuit and a buffer storage configured as a gas separator in the consumer circuit. Propane is used in the heat pump, and the heat pump is arranged in a safety area outside a building.
DE 102007039195 A1 shows an arrangement for air-conditioning of a vehicle, wherein a first cycle can be switched between a refrigeration mode and heating mode. CO₂circulates as a heat exchange fluid in the first super critically operable cycle. A coolant for a motor drive of the vehicle circulates in a second cycle.

SUMMARY

An embodiment may have an apparatus for temperature-controlling a space to be temperature-controlled with a space limitation separating the space to be temperature-controlled from a surrounding area, comprising: a primary heat pump circuit with an evaporator, a condenser, a compressor, and an expansion element, wherein the primary heat pump circuit comprises a natural primary working fluid, wherein the evaporator, the liquefier, the compressor, and the expansion element are suitable to be arranged outside of the space to be temperature-controlled; a secondary circuit thermally coupled to and fluidically decoupled from the evaporator or the condenser via a heat exchanger and comprising a temperature-controlling element configured to be arranged in the space to be temperature-controlled and configured to be connected to the heat exchanger via a line arrangement comprising a secondary fluid that differs from the primary working fluid, wherein the line arrangement is suitable to penetrate the space limitation, wherein the secondary circuit is configured as a thermosiphon cycle, and wherein a controllable pump configured to reverse a conveying direction in the secondary circuit as a response to a control signal is arranged in the secondary circuit; wherein the apparatus is configured to cool the space by means of the temperature-controlling element in a refrigeration mode; and a controller configured to cause, as a response to a control signal, a heat pump cycle reversal in the primary heat pump circuit so that, in the refrigeration mode, energy is dissipated from the heat exchanger through the primary heat pump circuit, and so that, in a defrosting mode, energy is supplied to the heat exchanger through the primary heat pump circuit in order to defrost the temperature-controlling element, and the conveying direction in the secondary circuit is reversed by the controllable pump.
Another embodiment may have a space to be temperature-controlled, comprising: a space limitation separating a space from a surrounding area of the space; and an apparatus according the invention.
Another embodiment may have a method for temperature-controlling a space to be temperature-controlled with a space limitation separating the space to be temperature-controlled from a surrounding area, with a primary heat pump circuit with an evaporator, a condenser, a compressor, and an expansion element, wherein the evaporator, the liquefier, the compressor, and the expansion element are arranged outside of the space to be temperature-controlled; and a secondary circuit thermally coupled to and fluidically decoupled from the evaporator or the condenser via a heat exchanger and comprising a temperature-controlling element arranged in the space to be temperature-controlled and connected to the heat exchanger via a line arrangement comprising a secondary fluid that differs from the primary working fluid, wherein the line arrangement penetrates the space limitation, wherein the secondary circuit is configured as a thermosiphon cycle, and wherein a controllable pump configured to reverse a conveying direction in the secondary circuit as a response to a control signal is arranged in the secondary circuit, comprising: using, in the primary heat pump circuit, a natural primary working fluid; using, in the line arrangement of the secondary circuit, a secondary fluid that differs from the primary working fluid, wherein temperature-controlling in a refrigeration mode comprises cooling the space by means of the temperature-controlling element; and as a response to the control signal, causing a heat pump cycle reversal in the primary heat pump circuit so that, in the refrigeration mode, energy is dissipated from the heat exchanger through the primary heat pump circuit, and so that, in a defrosting mode, energy is supplied to the heat exchanger through the primary heat pump circuit, in order to defrost the temperature-controlling element, and the conveying direction in the secondary circuit is reversed by the controllable pump.
Another embodiment may have a method for manufacturing an apparatus for temperature-controlling a space to be temperature-controlled with a space limitation separating the space to be temperature-controlled from a surrounding area, comprising: a primary heat pump circuit with an evaporator, a condenser, a compressor, and an expansion element, wherein the primary heat pump circuit comprises a natural primary working fluid, wherein the evaporator, the liquefier, the compressor, and the expansion element are arranged outside of the space to be temperature-controlled; a secondary circuit thermally coupled to and fluidically decoupled from the evaporator or the condenser via a heat exchanger and comprising a temperature-controlling element arranged in the space to be temperature-controlled and connected to the heat exchanger via a line arrangement comprising a secondary fluid that differs from the primary working fluid, wherein the line arrangement penetrates the space limitation, wherein the secondary circuit is configured as a thermosiphon cycle, and wherein a controllable pump configured to reverse a conveying direction in the secondary circuit as a response to a control signal is arranged in the secondary circuit, wherein, in a refrigeration mode, the apparatus is configured to cool the space by means of the temperature-controlling element, the method comprising: introducing a natural primary working fluid into the primary heat pump circuit; manufacturing a line arrangement that penetrates the space limitation; introducing, into the line arrangement, a secondary fluid that differs from the primary working fluid; and manufacturing a controller configured to cause, as a response to the control signal, a heat pump cycle reversal in the primary heat pump circuit so that, in the refrigeration mode, energy is dissipated from the heat exchanger through the primary heat pump circuit, and so that, in a defrosting mode, energy is supplied to the heat exchanger through the primary heat pump circuit so as to defrost the temperature-controlling element, and a conveying direction in the secondary circuit is reversed by means of the controllable pump.
An apparatus for temperature-controlling a space to be temperature-controlled with a space limitation separating the space to be temperature-controlled from a surrounding area includes a primary heat pump circuit with an evaporator, a condenser, a compressor, and an expansion element, wherein the primary heat pump circuit comprises a natural primary working fluid, wherein the evaporator, the condenser, the compressor, and the expansion element are arranged outside of the space to be temperature-controlled. This apparatus further includes a circuit that is thermally coupled to and fluidically decoupled from the evaporator and the condenser via a heat exchanger, and that comprises one or several temperature-controlling elements arranged in the space to be temperature-controlled and connected to the heat exchanger via a line arrangement comprising a secondary fluid that differs from the primary fluid, wherein the line arrangement penetrates the space limitation.
The present invention is based on the finding that in the primary heat pump circuit arranged outside of the space to be temperature-controlled, i.e. in the surrounding area of the space to be temperature-controlled, a natural primary working fluid that may have properties that are unfavorable for a closed space when being breathed in by an organism, such as flammability, is used. On the other hand, a different secondary fluid that is typically harmless or has low risks for an organism because it is non-flammable is used in the secondary circuit. Thus, according to the invention, primary working fluids and secondary fluids that have favorable properties for a compression or a primary heat pump circuit on the one hand and for the temperature control in a (closed) space to be temperature-controlled on the other hand can be combined with each other.
In particular, the use of flammable primary working fluids as an example of a natural refrigerant enables high environmental compatibility and good energy-efficient properties in a compressing refrigerating/heating cycle. On the other hand, such refrigerants/heating agents can generally only be used in closed spaces with considerable additional effort due to their flammability. Such refrigerants are, for example, hydrocarbons (HC) such a propane (R290) or propene (R1270). Other primary working fluids without F-gases include NH₃or NH₃/DME (R723), which are only slightly flammable, but toxic to the human organism in closed spaces and are therefore undesirable. This group of working fluids for refrigeration also includes fluorinated hydrocarbons, which are flammable due to their molecular composition.
On the other hand, non-flammable and therefore low-risk refrigerant/heat transfer media can be used in the secondary circuit, which is not used for refrigeration or heat generation, but only for cold distribution and heat distribution, which ideally undergo a change of phase when transporting cold or heat. Advantageously, a secondary fluid that changes its aggregate state during a heat transport is used. Heat is absorbed or released at a constant temperature and the thermosiphon principle is driven by the difference in density between vapor and liquid.
The line arrangement penetrating through the space limitation and the elements of the primary heat pump circuit, including at least part of the heat exchanger, being arranged outside of the space prevents a natural, such as a flammable, working fluid from entering the closed space. Only a non-critical heating medium with the heat/cold to be transported enters the closed space and releases the transported heat/cold into the space via the temperature-controlling element. The temperature-controlling element will typically be a secondary fluid-air heat exchanger, while the heat exchanger will be a primary working fluid-secondary fluid heat exchanger. The heat exchanger is then coupled to the condenser of the primary heat pump circuit if heating is to be achieved as the temperature control. However, if cooling is to be used as the temperature control, then the heat exchanger is thermally coupled to the evaporator of the primary heat pump circuit. In embodiments, the evaporator and the condenser are configured so that corresponding elements of the primary heat pump circuit can perform both functions depending on the operating direction of the compressor.
Furthermore, an implementation of the heat exchanger can be configured in such a way that the actual evaporator or condenser of the primary heat pump circuit is connected in series to the primary working fluid-secondary fluid heat exchanger. Alternatively, the functionality can also be integrated in a single element, which on the one hand achieves the evaporation/condensation in the primary heat pump circuit, and on the other hand transfers the heat or cold from the primary heat pump circuit to the secondary circuit. If the primary working fluid-secondary fluid heat exchanger is connected in series to the actual condenser or evaporator of the primary heat pump circuit, the arrangement of the two elements. i.e. whether the actual condenser or evaporator of the primary heat pump circuit is arranged in front of or behind the primary working fluid-secondary fluid heat exchanger in the direction of flow of the primary working fluid, freely selectable according to the actual conditions. If the two functions of evaporation or condensation of the primary heat pump circuit and that of heat transfer from one fluid to the other, while the two fluids are strictly decoupled from each other, are integrated into a single element, this element is also arranged outside of the space to be temperature-controlled, i.e. in the surrounding area separated from the space to be temperature-controlled by the space limitation.
In embodiments, the temperature-controlling element is an air-secondary fluid heat exchanger with a phase transition. In this case, the line arrangement of the secondary circuit comprises a first part through which the liquid secondary fluid flows, and a second part through which the vaporous secondary fluid flows. Depending on implementation, the secondary circuit can be implemented without a drive, i.e. solely according to the thermosiphon concept, in such a way that the secondary fluid is transported in the secondary circuit solely due to gravity and the difference in density between the vapor and liquid phases of the secondary fluid. Depending on the embodiment, however, a pump can also be arranged in a liquid-carrying part of the line arrangement to support the circulation of the secondary fluid, or a fan can be arranged in the vapor-carrying part of the line arrangement.
Especially when using such a support in the secondary circuit, it is advantageous to provide a controller that, depending on the direction of pumping or ventilation in the secondary circuit, causes defrosting to be carried out at certain times during a normal refrigeration application in the space to be temperature-controlled in order avoid icing of the temperature-controlling element and thus a loss of efficiency. In addition, the pump or fan controlled by the controller can also be used to switch to a refrigeration mode at selected times when the space to be temperature-controlled is actually to be heated, for example when a constant temperature is to be achieved, e.g. when air conditioning is to be achieved over a wide temperature range.
Advantageously, the controller is configured to change the cycle reversal in the primary heat pump circuit as well, which is equivalent to reversing the conveying direction of the compressor so that, for example, if the primary heat pump circuit operates in such a way that the evaporator is coupled to the heat exchanger, i.e. a cooling application is being carried out, the primary heat pump circuit operates in such a way that the evaporator becomes a condenser by switching the conveying direction of the compressor. This supplies heat to the heat exchanger, which means that heat is also supplied to space to be temperature-controlled. Switching the conveying direction the compressor can be achieved by switching the rotational direction of a compressor wheel or by switching a four-way valve coupled to the pressure side and the suction side of the evaporator and condenser of the primary heat pump circuit.
If the secondary circuit does not have a pump or a fan, i.e. if it purely operates according to a thermosiphon principle, by switching the conveying direction of the compressor or by reversing the refrigeration cycle, e.g. by means of valves in the primary heat pump circuit, it can also be achieved that a switch is made from a refrigeration mode to a heating mode, for short-term defrosting, or from a “normal” heating mode to a refrigeration mode, e.g. for temperature-controlling purposes, etc., while also suppling cold or heat to the element to be temperature-controlled.
An alternative to the use F-gases as refrigerants is the use of so-called natural refrigerants. The use of hydrocarbons (HC) is particularly advantageous here, as these substances, in contrast to F-gases, have a very low or negligible global warming potential and enable a high energy efficiency of the refrigerant process and therefore only little drive energy is required per refrigerating or heating capacity. A disadvantage of hydrocarbons is their high flammability, which restricts the use in small closed spaces, such as with the refrigeration structures and refrigeration containers considered here, but also other closed spaces to be cooled or air-conditioned, or virtually excludes their safe use.
To minimize risks, the goal is therefore to use as little refrigerant as possible and to prevent the refrigerant from entering the closed refrigeration structures and refrigeration containers and other closed spaces to be air-conditioned. This results in the use of components for refrigeration with a minimum refrigerant volume in order to the keep the filling level of the refrigerant as low possible. Micro-channel technology and plate heat exchangers are particularly suitable technologies for the heat exchangers. In addition, the compactness of the overall system and the avoidance of storage volumes, such as frequently used refrigerant collectors, has to be taken into account. The compressor should have a low refrigerant volume and a low filling level of oil in order to further reduce the refrigerant mass required for the process. This approach of refrigerant reduction or minimization also applies to all other components to be used in the process and should ideally be taken into account when selecting and positioning them.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will be detailed subsequently referring to the appended drawings, in which:

FIG. 1 shows an apparatus for temperature-controlling a space to be temperature-controlled according to embodiments of the present invention;

FIG. 2A shows a simple primary heat pump circuit to cool a space;

FIG. 2B shows a simple primary heat pump circuit to heat a space;

FIG. 3 shows an apparatus for temperature-controlling with a heat exchanger coupled to the evaporator or condenser of the primary heat pump circuit;

FIG. 4 shows an apparatus for temperature-controlling according to an embodiment with a thermosiphon concept;

FIG. 5 shows an embodiment of the present invention with the thermosiphon concept for refrigeration;

FIG. 6 shows a further embodiment of the apparatus for temperature-controlling with the thermosiphon concept for heating;

FIG. 7 shows a pump-supported thermosiphon implementation for refrigeration or heating, depending on the pump direction;

FIG. 8A shows a schematic illustration of a pump with an inner stator;

FIG. 8B shows a schematic illustration of a pump with an outer stator;

FIG. 9 shows an embodiment for the apparatus for temperature-controlling with a pump-supported thermosiphon concept for heating;

FIG. 10 shows a pump-supported thermosiphon concept for refrigeration;

FIG. 11 shows a pump-supported thermosiphon concept for heating;

FIG. 12 shows an implementation of the apparatus for temperature-controlling according to the present invention with a ventilator in a vapor-carrying part of the line arrangement for refrigeration;

FIG. 13 shows a schematic illustration of the fluidically decoupled and thermally coupled heat exchanger.

FIG. 14 shows a schematic implementation of a heat exchanger separated from the actual evaporator or condenser with a (variable) liquid level of liquid secondary fluid;

FIG. 15 shows a schematic illustration of an obliquely arranged temperature-controlling element with channels for a secondary fluid connected via fins through which air driven by a blower can flow.

FIG. 16A shows an implementation of the apparatus for temperature-controlling according to the present invention for refrigeration with a plate heat exchanger as an integrated element and an air register arranged perpendicularly;

FIG. 16B shows an implementation of the apparatus for temperature-controlling according to the present invention for heating with an integrated element and a temperature-controlling element perpendicularly arranged on a similar height and a pump;

FIG. 16C shows an implementation of the apparatus for temperature-controlling according to the present invention for cooling with an integrated element and a temperature-controlling element perpendicularly arranged on a similar height and a pump;

FIG. 17A shows an implementation of the apparatus for temperature-controlling according to the present invention and for refrigeration with a plate heat exchanger as an integrated element and an air register arranged perpendicularly and configured in an alternative way;

FIG. 17B shows an implementation of the integrated element configured as a plate heat exchanger; and

FIG. 17C shows an implementation of the apparatus for temperature-controlling according to the present invention for refrigeration with a plate heat exchanger as an integrated element of FIG. 17B and an air register arranged perpendicularly and configured in an alternative way.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows an apparatus for temperature-controlling a space 5 to be temperature-controlled with a space limitation 20 separating the space 5 to be temperature-controlled from a surrounding area. The apparatus includes a primary heat pump circuit 6 with a evaporator 4, a condenser 2, a compressor 1, and an expansion element 3, wherein the primary heat pump circuit comprises a natural primary working fluid, wherein the compressor 1, the evaporator 4, the condenser 2, the compressor 1 and the expansion element 3 are arranged outside of the space 5 to be temperature-controlled. The apparatus according to the invention further includes a secondary circuit thermally coupled to and fluidically decoupled from the evaporator 4 and the condenser 2 via a heat exchanger 7, and comprising a temperature-controlling element 14. The temperature-controlling element 14 is arranged in the space 5 to be temperature-controlled and is connected to the heat exchanger 7 via a line arrangement 15 a and 15 b. The line arrangement comprises a secondary fluid that differs from the primary fluid. Furthermore, the line arrangement 15 a and 15 is configured to penetrate the space limitation.
When the secondary circuit is coupled to the evaporator 4 via the heat exchanger 7, the arrangement is in the refrigerating (or cooling) mode for the space to be temperature-controlled. Temperature-controlling is then refrigeration and the temperature-controlling element 14 functions as a refrigerating element. In contrast, when the secondary circuit is coupled to the condenser 2 of the primary heat pump circuit via the heat exchanger 7, the apparatus for temperature-controlling is used as a heating apparatus, and temperature-controlling the space 5 is heating, wherein the temperature-controlling element 14 functions as a heating element.
Thus, the heat exchanger 7 may comprise the evaporator or liquefier as well as the heat exchanger 10 illustrated in the various drawings. The temperature-controlling element 14 may consist of the heat exchanger 11 illustrated in the various drawings or may comprise one or several additional elements, such as sensors or the blower of FIG. 15 .
In the embodiment, a controller 30 is provided so as to switch the compressor 1 of the primary heat pump circuit in its conveying direction, i.e. via a control signal 31, so as to switch the primary heat pump circuit with respect to the flow direction of the primary working fluid. With the same coupling of the secondary circuit, this achieves that the function of the secondary circuit is changed as well, i.e. the secondary circuit is in the refrigeration mode or in the heating mode. If the secondary circuit is normally in the refrigeration mode, the heating mode is used so as to achieve defrosting of the temperature-controlling element 14. However, if the secondary circuit is mainly in the heating mode, intermittent refrigeration can be used to keep a certain set temperature bandwidth. The initiative to output the control signal 31 or the control signal 32 from the controller 30 to a pump or ventilator element possibly arranged in the secondary circuit, such as the element 8, may originate from a sensor, a clock generator, or an external signal, as illustrated by the control input 33. However, if the controller is configured to be controlled via a sensor input or a clock generator, the clock generator or the sensor input would be connected to the control input 33, or the control input 33 would not exist and the initiative for the output of the control signal 31/32 is generated from the controller 30.
Switching the conveying direction of the compressor may be achieved in several ways. In one embodiment, the compressor 1 has a conveyor wheel. In this case, the compressor is configured to reverse a rotational direction of the conveyor wheel as a response to the control signal 31 for reversing the conveying direction.
In another embodiment, the compressor includes a four-way valve. In this case, for reversing the conveying direction, the compressor is configured to, as a response to the control signal 31, e.g. on the basis of the refrigeration mode, fluidically decouple a suction side of the compressor from the evaporator 4 and fluidically connect the same to the condenser 2 or to fluidically decouple a pressure side of the compressor from the condenser 2 and to fluidically connect the same to the evaporator 4. In this case, the element that was in the refrigeration mode takes over the function of the condenser in the heating mode or defrosting mode.
On the basis of the defrosting mode, for reversing the conveying direction, a suction side of the compressor is fluidically decoupled from the condenser (which was the evaporator in the defrosting mode) and the same is fluidically connected to the evaporator 4 (which was the condenser in the defrosting mode), and a pressure side of the compressor is fluidically decoupled from the evaporator 4 (which was the condenser in the defrosting mode) and is fluidically connected to the condenser 2 (which was the evaporator in the defrosting mode).
As shown in FIG. 1 , the secondary circuit may be provided with a pump 8 so as to circulate the secondary fluid in the secondary circuit and in particular in the line arrangement 15 a, 15 b. The secondary fluid may be a secondary liquid when the temperature-controlling element 14 functions as a heat exchanger without a change of phase. However, if the temperature-controlling element 14 functions as a heat exchanger with a change of phase, as illustrated in FIGS. 4 to 12, 15 , for example, a part, such as the part 15 a of the line arrangement, is the liquid-carrying part and the other part, such as the part 15 b, is the vapor-carrying part of the line arrangement in the secondary circuit.
The refrigeration process 6, as illustrated in FIG. 3 , when using the described components and refrigerants, is performed according to the same principle as initially described, with the only difference that the filling quantity is now significantly reduced, the refrigerant cannot reach the interior of the structure, or container, allowing a flammable refrigerant with a strongly decreased risk to be used for refrigeration and heat generation.
The generated cold and heat of the refrigerant process is subsequently transported indirectly via a suitable heat exchanger, such as a plate heat exchanger 7, with a non-flammable secure working medium, a so-called secondary fluid, into the refrigeration structure, refrigeration container, or space to be cooled in general. Therefore, the refrigeration system consists of a primary cycle for refrigeration and a secondary cycle for the transport of cold or heat.
This secondary cycle for distributing the generated cold and heat can be carried out in different ways. There is the possibility to use a brine that is conveyed from a suitable pump 8 and therefore removes the heat from the space to be cooled or introduces the same into the space to be heated and transports the same to the refrigerant-carrying part of the machine, i.e. the primary cycle, without a change of phase in the secondary cycle 9.
A further variation is the use of a substance that is also conveyed by means of a pump with a change of phase and flows through the heat exchanger of the closed space and in this way removes the heat from the same or introduces the heat. In this case, the secondary cycle transports the heat to the refrigerant-filled part of the machine, i.e. the primary cycle. Advantageously, the change of phase is a liquid-gaseous change of phase so as to ensure the ability to pump the secondary fluid. A change of phase from solid to liquid in the form of a slurry, i.e. a mixture of watery ice and glycol, is generally not ruled out.
Forced-driven secondary cycles, i.e. with the use of a pump, have the disadvantage that the pump possibly needs energy for overcoming the flow resistances of the secondary system. An alternative that does not require the use of a pump is the design of the secondary cycle as a thermosiphon cycle, shown in FIG. 4 . In this case, the working medium is condensed with a change of phase of the secondary cycle (the secondary fluid) in the evaporator 10 of the refrigerating part of the machine by introducing the same in a vaporous form into the upper part 10 b of the heat exchanger (evaporator of the primary cycle) and by the same exiting in the lower region as a liquid 10 a. Now, by means of suitable pipelines, the liquid working medium is guided into the closed space to be cooled, where it flows into a cooler 11 into which it has entered in the lower part in its liquid form 11 a and which it exists in the upper part in its gaseous form 11 b so as to be subsequently again led to the heat exchanger 10 of the refrigerating part of the machine 7 in which the working medium is then again condensed and flows back to the cooler in the refrigerating space solely via gravity, which leads to leveling. This self-circulation has the advantage that it does not require a pump with a corresponding energy consumption and risk of failure, but only requires a minimum number of components to be used. The secondary cycle has to be designed such that, when operating the system, a driving pressure difference is created by geodetic height differences and/or by the thermosiphon effect. In this case, it is particularly advantageous if the cooler is flooded in the refrigeration case since this ensures a maximum use of the air side of the cooler.
In the use case in which heat has to be transported to the closed space or the evaporator is to be defrosted, the process is reversed by now supplying energy to the heat exchanger 10 and by evaporating the liquid phase of the secondary fluid 10 a and by the same exiting the heat exchanger as a gaseous phase 10 b and by supplying the same to the heat exchanger 11 in the closed space via a suitable pipeline. The refrigerant enters the heat exchanger in the closed space 11 as vapor 11, is then condensed, dissipates its heat, and flows in its liquid form 11 a back out of the heat exchanger into the refrigerating heat exchanger 10 of the machine, where the evaporation process starts again. When transporting heat into the closed space, this process is also carried out exclusively on the basis of the geodetic height difference of the liquid phase in the two heat exchangers by having a level equalization in both components due to gravity.
When being designed accordingly, each of the described methods also enables the reversal of the cycle, so that the heat exchanger 11 of FIG. 4 in the closed space 5 is able to both carry out defrosting and heating. Depending on the use of the space to be cooled, this process can occur several times a day and there is a requirement to be able to quickly and reliably carry out defrosting. The defrosting process is realized by the refrigerating part of the machine, the primary cycle, no longer operating as a refrigeration system, but switching into the heat pump mode or the heating gas mode, as illustrated in FIG. 5 . Thus, as described, in the heat pump mode, the condenser becomes the evaporator and the evaporator becomes the condenser. In the heating gas mode, the condenser of the refrigerant cycle does no longer experience a flow through the same and the heat is instead dissipated in the evaporator. Thus, there is the possibility that the refrigerating unit of the machine transports heat to the secondary cycle and that the same transports the heat into the refrigerating container, and therefore makes it possible that the cooler 11 in the refrigeration container is also heated and makes it possible to quickly and efficiently defrost the cooler in the container. The same also applies for the continuous heating operation of the container, if the external temperature is below the target temperature in the container.
The condenser of the refrigerating part of the machine, as well as the heat exchanger in the closed space, or of the container, are usually operated with a force convection generated by an appropriate blower on the air side. Similar to the refrigerating part of the machine, the primary cycle, with respect to the secondary cycle it should be also taken into account that the filling quantities of the working medium are kept at a minimum and that a cooler that not only has a small inner volume but also a small thermal mass is used so as to be able to carry out the defrosting process as quickly and therefore energy-efficient as possible. Thus, all heat exchangers with a low refrigerant filling quantity and a minimum use of material can be used for the heat exchanger 11 in the closed space, e.g. micro-channel technologies, which particularly correspond to the requirements. Other structures, such as finned heat exchangers can be also used as an alternative. Both heat exchanger types are ideally operated in a flooded manner.
Due to the omission of pumps through the use of thermosiphon solutions and the resulting energetic advantages as well as the decrease of complexity of the system, such solutions have particular advantages compared to the initially described conventional technology and are therefore advantageous in the field of compact systems with spatial distances of advantageously up to 10 meters and refrigerating or heating capacities of below 50 kW and particularly advantageously of up to 2 meters between the two heat exchangers 10 and 11 and with low refrigerating and heating capacities of below 10 kW.
If, in a use case considered, it is not necessary that the refrigerating machine can also be used to heat the closed space, if required, it is advantageous in any case to arrange the heat exchanger 11 in the closed space 5 geodetically below the heat exchanger 10, where the refrigerant flows through the same, with reference to FIG. 5 . In this case, how much the heat exchanger in the closed space 11 is positioned below the heat exchanger 10 through which the refrigerant flows is irrelevant. Arranging the heat exchangers in relation to each other ensures the heat exchanger in the closed space 11 is fully filled with the secondary fluid 11 a in each operating point, while the heat exchangers 10 through which the refrigerant flows is available for condensation of the vaporous refrigerant 10 a with its entire surface area, with said refrigerant being conveyed to the same from the heat exchanger 11 in the enclosed space 5.
In case that only heat has to be introduced into the closed space, with this case being illustrated in FIG. 6 , it is advantageous if the heat exchanger 11 arranged in the space 5 is located geodetically above the heat exchanger 10 through which the refrigerant flows. Here, it is relevant how the difference in the geodetic height is actually selected in the application. In any case, it is ensured that the energy supplied to the heat exchanger 10 evaporates the secondary fluid, the vapor 11 b subsequently flows into the heat exchanger 11 in the closed space 5, and dissipates there its previously captured heat to the space during condensation. After the heat dissipation, driven by gravity, the condense secondary fluid 11 a flows back through the heat exchanger 10 through which the refrigerant flows so that it can be evaporated there again by heat supply.
In certain installation situations and operating conditions of the arrangement of the components, illustrated in FIG. 4 , there may possibly be an impairment of the transferred power into the closed space 5. For example, this may be due to the constructive limitation of possibilities of the horizontal arrangement in relation to each other, due to possible limitations of the installation height of the heat exchangers 10 and/or 11, or due to holistic constructive limitations which, e.g., are the reason that the connection lines between the two heat exchangers 10 and 11 cannot be sufficiently dimensioned to ensure a flow with as little pressure loss as possible.
These cases use the solution illustrated in FIG. 7 , in which a pump 8 is a remedy for the above-described drawbacks. In this case, it is essential that this pump, in contrast to pumps that are used conventionally, does not have to have a particular conveying stroke in the sense of a large conveying height, but that it only supports the self-compensation of the liquid levels in the heat exchangers 10 and 11, which is given in any case by the thermosiphon effect described. Desirably, support of the autonomous flow is done by reversal of the rotational direction of the rotor 13 and for example or particularly by switching the polarity of the stator 120 in both flow directions of the secondary fluid so that the heat exchanger 11 located in the closed space can be cooled and heated for the above described reasons.
FIG. 8 illustrates two conceptual construction possibilities for such a pump 8. FIG. 8 a shows the variation in which the rotor 13 and the stator 120 of the motor driving the propeller 140 are located in the pipeline and therefore in the secondary fluid. In this construction, the electric energy driving the motor may be guided through the pipe leading the secondary fluid, which may be ensured by a component 15 that simultaneously positions the motor in the pipe.
FIG. 8 b shows the variation of the pump in which the stator 120 of the pump motor is located in the atmosphere outside of the pipe through which the secondary fluid flows, while the rotor 13 driving the propeller 140 via a shaft is located in the fluid flow within the pipe. In this construction, it is not necessary to guide the electric energy to generate the magnetic field through the stator 120. This construction also makes it possible to reverse the rotational direction of the propeller 140 and therefore the flow direction of the secondary fluid by reversing the polarity at the stator or by any other suitable measure.
In FIG. 7 , in the arrangement of the heat exchangers 10 and 11 as illustrated in FIG. 4 , the resulting height difference of the liquid levels 10 a and 11 a of the secondary fluid in the two heat exchangers 10 and 11 is illustrated when such a pump is used. It can be seen that the heat exchanger 11 in the closed space 5 has a higher liquid level 11 a than the heat exchanger 10 connected to the refrigerant. This makes it possible to apply refrigerant to a larger surface area of the heat exchanger 11 in the closed space 5, while at the same time having available a larger surface area 10 b for condensing the secondary fluid in the heat exchanger 10, increasing the transferred energy of the two heat exchangers.
The possibility to reverse the conveying direction of the pump by changing the pole of its motor results in the use case of heating the heat exchanger 11 to heat the closed space 5, illustrated in FIG. 9 , or to carry out defrosting in the case of the heat exchanger 11 being frozen. In this case, the pump sucks the liquid secondary fluid 11 a out of the heat exchanger 11 in the closed space 5 and conveys the same into the refrigerant-carrying heat exchanger 11, which is why the liquid phase of the secondary fluid 10 a in this heat exchanger comprises a higher liquid level than in the heat exchanger 11. Thus, there is a larger surface area available in the heat exchanger 10 for evaporation of the secondary fluid, while there is a larger surface area 11 b for condensation in the heat exchanger 11, increasing the capacity of the two heat exchangers.
Finally, FIG. 10 and FIG. 11 show the uses cases that result if an orientation of the two heat exchangers 10 and 11 on the same geodetic height is not possible due to constructive circumstances. FIG. 10 illustrates the case in which the refrigerant-carrying heat exchanger 10 is located below the heat exchanger 11 located in the closed space 5. The pump is able to lift the liquid level of the secondary fluid 11 a to such an extent that it is above the liquid level 10 a in the refrigerant-carrying heat exchanger. Thus, despite the possibilities being impaired due to constructive circumstances, the function of the heat exchange is maintained.
FIG. 11 shows the case in which the refrigerant-carrying heat exchanger 10 is located geodetically above the heat exchanger 11 in the closed space 5. In this use case, the pump is also responsible for the liquid level 10 a of the secondary fluid in the refrigerant-carrying heat exchanger 10 being above the liquid level 11 a of the heat exchanger 11 in the closed space 5.
Alternatively to the cases illustrated in FIGS. 7-11 , in which a pump is used to support the flow of the secondary fluid, it is also possible to introduce into the line a conveying apparatus 12 through which the vapor phase of the secondary fluid flows exclusively. The configuration of the component supporting the vaporous phase of the secondary fluid in its natural flow direction corresponds in principle to the configuration of the pump 8, illustrated in FIGS. 7-11 , with the difference that the conveying means 12 may be optimized for the flow of vaporous fluids, e.g., by the conveying element having a geometry that is particularly suitable to convey vapors.
In the case illustrated in FIG. 12 , the conveying means 12 conveys the vaporous phase 11 b out of the heat exchanger 11 in the closed space 5 towards the heat exchanger 10 where the secondary fluid in its vaporous form 10 b then displaces the liquid phase 10 a and therefore is responsible for the geodetic height difference between the fluid in the heat exchanger 10 and the heat exchanger 11 illustrated in FIG. 12 . The application of the illustrated conveying means 12 illustrated in FIG. 12 corresponds to the case illustrated in FIG. 7 ; however, it can also be fully applied to the use cases illustrated in FIGS. 9-11 by replacing the pump 8 with the conveying unit 12 and by then supporting the circulation of the secondary fluid in the respectively illustrated direction.
FIG. 13 shows a schematic arrangement of the heat exchanger for coupling the secondary circuit and the primary heat pump circuit. In particular, the channel for the primary working fluid arriving from the expansion element 3 and indicated with 14 a and the channel for the primary heat pump fluid exiting the heat exchanger 7 and indicated with 14 b enter into the heat exchanger, wherein this channel is connected to the compressor 1.
Simultaneously, the first part 15 a of the line arrangement is illustrated as it enters into the heat exchanger 7, wherein the second part of the line arrangement 15 b entering into the heat exchanger 7 is illustrated as well. 22 in FIG. 13 indicates the effective zone in which the thermal transfer from the primary heat pump circuit to the secondary heat pump circuit takes place. In particular, the two cycles are thermally coupled but fluidically decoupled so that a highly efficient natural refrigerant, e.g. made of hydrocarbons, may be used in the primary heat pump circuit, while a secondary fluid having no risk of flammability may be used within the space limitation 20.
Even though FIG. 1 exemplarily shows that the heat exchanger is arranged fully outside of the space 5 and the actual lines of the secondary circuit penetrate the space limitation 20 outside of the heat exchanger, the arrangement of the heat exchanger 7 may also be configured to be “embedded” into the space limitation 20 so that the supply or discharge to the effective region 22 already arranged within the outer limitation of the heat exchanger 7 functions as the line arrangement penetrating the space limitation. This is indicated in FIG. 13 by the dotted line 20 a or 20 b arranged within the outer limitation of the heat exchanger 7 and being penetrated by the line arrangement 15 a and 15 b within the heat exchanger 7.
FIG. 14 shows an embodiment of the apparatus for temperature-controlling, in particular with respect to a special implementation of the heat exchanger. In particular, the heat exchanger 7, which may be configured as a plate heat exchanger or braze plate heat exchanger, is configured by a mutual element illustrated at 10 and uniting the functionality of the heat exchanger and the condenser 2 or the evaporator 4. In an implementation that is an alternative to the one according to FIG. 14 , heat exchangers 10 may be connected in front of the evaporator or condenser, i.e. they may be implemented by two separate elements. Alternatively, the sequence of the two elements of heat exchanger 10 and evaporator/ condenser 4 or 2 may be reversed so that the output liquid of the evaporator is fed into the heat exchanger.
However, it is advantageous to integrate both functionalities into one element 10. The primary working fluid flows in the channels 40 illustrated in FIG. 14 , which are fed by an expander 41 and are united back into the line 14 b by a collector 42, and the second fluid flows via the connections 15 a and 15 b. In the case of the heat exchanger functioning as an evaporator 4, hot vapor is fed into the heat exchanger 10 via the line 15 b from the space to be temperature-controlled. This leads to the primary working fluid being evaporated after its entry into the channels 40 and the vapor being collected by the collector 42 and the same being sucked in by the compressor 1. The secondary vapor supplied by the connection 15 b condenses on the outside of the channels 40 due to the evaporator, and drips into the area with the variable liquid level. Refrigerated liquid is then brought into the temperature-controlling element of FIG. 15 via the connection 15 a by means of the siphon principle or by means of a pump, so as to cool the space to be temperature-controlled.
In the reverse case, i.e. if the room to be temperature-controlled is to be heated, the exchanger acts as a condenser for the primary working fluid. In this case, vaporous and compressed warm primary working fluids flows into the channels 40, which are located as far in the cool liquid secondary fluid as possible, via the element 42, which now acts as an expander. Through this, the primary working fluid condenses on the inside of the channels 40 and leaves the heat exchanger 10 as a liquid via the element 41, which now acts as a collector. Through this, the secondary fluid evaporates in the heat exchanger 10, and vapor flows across through the connection 15 b into the temperature-controlling element 11, 14 so as to heat the space. Through this, the secondary fluid condenses in the temperature-controlling element and returns into the heat exchanger as a liquid due to the siphon principle or via a pump so as to be evaporated again.
FIG. 14 shows the heat exchanger 10 such that it comprises a variable liquid level which covers part of the effective heat exchanger volume and leaves blank another part in the embodiment shown in FIG. 14 . This will correspond to the case of FIG. 4 , FIG. 5 , FIG. 7 , FIG. 9 , FIG. 10 , FIG. 11 , FIG. 12 , in which the heat exchanger 10 is not fully flooded. In particular, the heat exchanger is configured such that, separate from the liquid level, the lower area 10 a is full of secondary liquid, while the upper area 10 b is a vapor space in which vaporous secondary fluid is arranged. At the same time, the first part 15 a of the line arrangement is the liquid-carrying part, while the second part 15 b of the line arrangement is the vapor-carrying part. Thus, it is advantageous that the diameter of the second line arrangement is significantly larger than the diameter of the first part so that the vapor can flow out as efficiently as possible and has enough space.
In addition, the heat exchanger 10 is shown as a volumetric micro-channel heat exchanger in which the expansion element or collection element 41 couples the line 14 a to the individual channels of the micro-channel heat exchanger, while a collection element or expansion element 42 is collecting or distributing the liquid (in the case of two separate elements) or vaporous (in the case of the integrated element and the refrigerating operation) primary fluid on the output side, and only supplies the same to the evaporator or condenser in the case of the separate implementation. Even though this is not shown in FIG. 14 , fins may be arranged between the micro-channels so as to provide for a better heat exchange, which are advantageously perforated so that bubbles may rise in the element 10 or drops may fall from top to bottom in the element 10.
In the apparatus according to an embodiment, the evaporator 4 or the liquefier 2 of the primary heat pump circuit is configured so as to be integrated into the heat exchanger 10. For example, with respect to FIG. 14 , the heat exchanger 10 comprises a first connection portion, e.g. the collector or expander 41 for the primary working fluid, a second connection portion, e.g. the collector or expander 42 for the primary working fluid; a third connection portion 15 a for the secondary fluid; a fourth connection portion 15 b for the secondary fluid, and a channel portion 40 extending between the first connection portion 41 for the primary working fluid and the second connection portion 42 for the primary working fluid.
Furthermore, an interaction region 43 extending between the third connection portion 15 a for the secondary fluid and the fourth connection portion 15 b for the secondary fluid is provided. The channel portion 40 is arranged in the same, wherein the channel portion 40 is thermally coupled to the interaction region 43 and fluidically decoupled from the interaction region 43.
Condensation and evaporation of the primary circuit takes place in the channel portion within the interaction space. Furthermore, due to condensation or evaporation in the primary circuit in the interaction region, there is evaporation or condensation of the primary fluid on the outside at the channel portion. Advantageously, the interaction region is the volume limited by a wall hand having the variable liquid level.
FIG. 15 shows an implementation of the temperature-controlling element configured as a secondary fluid-air heat exchanger, wherein this heat exchanger is again configured as a schematic micro-channel heat exchanger. Channels for the secondary fluid connected by fins are shown here again. Furthermore, a blower 35 arranged in the space and blowing air present in the space through the temperature-controlling element 14 is illustrated above the temperature-controlling element. Furthermore, FIG. 15 shows the optional oblique arrangement, i.e. with an angle α with respect to the horizontal line, as illustrated in thermosiphon applications and pump applications of FIGS. 3 to 12 . This leads to the fact that if the temperature-controlling element is not fully flooded, as exemplarily shown in FIG. 9 , only the lower left region of the channels in the temperature-controlling element is filled with secondary fluid, while the upper part of the channels is filled with vaporous secondary fluid. However, as illustrated in FIG. 5 , if the temperature-controlling element is fully flooded, the secondary fluid in the channels reaches up to the connection point of the vapor line 15 b, i.e. up to the top, so that there is only a small vapor space 11 b from which the vapor may be dissipated via the connection point of the second part 15 b of the line arrangement so as to be fed into the heat exchanger 10 of FIG. 14 via the line 15 b. In addition, the liquid line 15 a of the temperature controlling element in FIG. 15 is connected to the connection 15 a at the bottom of the heat exchanger 10.
FIG. 14 shows the functionality of the heat exchanger and the evaporator or condenser in an integrated element as a further embodiment so that the function of a heat exchange from the primary working fluid to the secondary fluid takes place within the evaporator and at the same time the functionality of evaporation or condensation takes place in the primary heat pump circuit.
FIG. 16 a shows an implementation of the apparatus for temperature-controlling according to the present invention for refrigeration with a plate heat exchanger as an integrated element and an air register arranged perpendicularly. Furthermore, a pump 8 pumping refrigerated secondary fluid into the temperature-controlling element 11 in which the air register is arranged perpendicularly is provided. The temperature-controlling element does not have to be arranged obliquely or fully perpendicularly. It may have any arrangement and configuration as long as an evaporation of the secondary fluid due to the heat in the space to be temperature-controlled can take place and the evaporated secondary fluid is able to reach the vapor space of the heat exchanger 10 via the connection 15 b.
FIG. 16 b shows an implementation of the apparatus for temperature-controlling according to the present invention for heating with an integrated element and a temperature-controlling element arranged perpendicularly on a similar height and a pump. A pump 8 achieving different liquid levels in the elements 10 and 11 is arranged again. Without the pump 8 or with an idle pump 8, the two levels would be on the same height due to the siphon principle. Due to the pump 8 pumping liquid into the heat exchanger 10 and the primary circuit being operated such that the integrated heat exchanger simultaneously functions as the condenser 2, secondary fluid in the heat exchanger is evaporated at the warm channel region of the condenser and is pushed into the temperature-controlling element. There, the warm vaporous secondary fluid dissipates its heat to the space to be temperature-controlled, which is why it condenses in the air register and is returned back to the exchanger 10 through the pump.
FIG. 16 c shows an implementation of the apparatus for temperature-controlling according to the present invention for refrigeration with an integrated element and a temperature-controlling element arranged perpendicularly on a similar height and a pump. A pump 8 that achieves different liquid levels in the elements 10 and 11 is arranged again. Without the pump 8 or with an idle pump 8, the two levels would be on the same height due to the principle of communicating pipes. Due to the fact that the pump 8 pumps liquid into the heat exchanger 10 and the primary circuit is operated such that the integrated heat exchanger simultaneously functions as the evaporator 2 in the primary circuit, evaporated secondary fluid is condensed in the heat exchanger at the cold channel region of the evaporator and is pushed into the temperature-controlling element via the pump as refrigerated liquid. There, the cold liquid secondary fluid absorbs heat from the space to be temperature-controlled by the same evaporating in the temperature-controlling element. This vapor returns to element 10 so as to condense there again.
FIG. 17 a shows an implementation of the apparatus for temperature-controlling according to the present invention for refrigeration with a plate heat exchanger as an integrated element and an air register arranged perpendicularly and configured alternatively. The pump 8 only supports the fluid circulation, since the elements 10, 11 have the same pressure with respect to the secondary fluid.
FIG. 17 b shows an implementation of the integrated element configured as a plate heat exchanger. The same includes the four connection portions 41, 42, 15 a, 15 b for the primary working fluid and the secondary fluid, which extend through the cover plate and are separated by the sealing plates. This channel region 40 for the primary fluid and the interaction region 42 are realized by the channel plates. Thus, the primary fluid is fluidically separated from the secondary fluid, but is thermally coupled to the same.
FIG. 17 c shows an implementation of the apparatus for temperature-controlling according to the present invention for refrigeration with the plate heat exchanger as an integrated element of FIG. 17 b and an air register arranged perpendicularly and configured alternatively. The pump achieves the different liquid levels in the plate heat exchanger and the air register. In case of an idle pump, the liquid levels would have the same height.
Subsequently, implementations of the present invention are summarized as examples.

- 1. A refrigeration system for temperature-controlling, i.e. for refrigerating or heating as required, of advantageously closed spaces in advantageously mobile or stationary applications on the road, rail, water or land,
- wherein a refrigerating part of the machine has no direct contact to the advantageously closed space to be temperature-controlled, and/or
- wherein a secondary circuit prevents that the refrigerant from the refrigerating part of the system is able to reach into the advantageously closed interior space of the application, and/or
- wherein the separation between the refrigeration and cold distribution with a flammable refrigerant or working fluid in the refrigerating part, and/or
- wherein, in the cold-distributing part of the system advantageously arranged in the space or in communication with the space, a non-flammable fluid with a change of phase between its liquid and gaseous aggregate state is used, and/or
- wherein the required electric drive power for the cold distribution through the secondary fluid is advantageously below ten percent of the overall required drive power of the machine for refrigeration or heating.
- 2. A machine according to example 1, wherein the working pressure of the secondary cycle fluid for cold distribution is above the working pressure of the fluid of the system part for refrigeration.
- 3. A machine according to any of the preceding examples, wherein the secondary cycle is purely configured as a thermosiphon solution so that no electric drive power is required.
- 4. A machine according to any of the preceding examples, wherein the secondary cycle comprises a pump means for the secondary fluid and effective in both flow directions, supporting the natural circulation by means of the thermosiphon principle and therefore also the refrigeration or heating operation.
- 5. Machine according to any of the preceding examples, which is only used for cooling the interior space and in which the heat exchanger in the interior space is located geodetically lower than the heat exchanger between the refrigerating and the cold-distributing system part.
- 6. A machine according to any of the preceding examples, which is only used for heating the interior space and in which the heat exchanger in the interior space is located geodetically higher than the heat exchanger between the refrigerating and the cold-distributing system part.
- 7. A pump means that is able to pump the secondary fluid in its liquid or gaseous phase by means of a change of rotational direction of the drive motor and a corresponding suitable geometry of the conveying unit into both conveying directions in a flow-wise manner so as to support the refrigeration and the heating operation of the interior space, alone or in connection with the machine according to any of the preceding examples.
- 8. A conveying means for supporting the circulation of the secondary fluid introduced into the cycle such that the same supports, via a generation of a pressure difference exclusively in the gaseous phase of the secondary fluid, its circulation in the cycle alone or in connection with the machine according to any of the preceding examples.
- 9. A pump means according to example 7, wherein the current-carrying region of the motor is located outside of the pipe through which the secondary fluid flows.
- 10. A pump means according to example 7, wherein the current-carrying region of the motor is located within the pipe through which the secondary fluid flows.

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 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 may be performed by such a device.
While this invention has been described in terms of several embodiments, there are alterations, permutations, and equivalents which fall within the scope of this invention. It should also be noted that there are many alternative ways of implementing the methods and compositions of the present invention. It is therefore intended that the following appended claims be interpreted as including all such alterations, permutations and equivalents as fall within the true spirit and scope of the present invention.

Claims

1. Apparatus for temperature-controlling a space to be temperature-controlled with a space limitation separating the space to be temperature-controlled from a surrounding area, comprising:

a primary heat pump circuit with an evaporator, a condenser, a compressor, and an expansion element, wherein the primary heat pump circuit comprises a natural primary working fluid, wherein the evaporator, the liquefier, the compressor, and the expansion element are suitable to be arranged outside of the space to be temperature-controlled;

a secondary circuit thermally coupled to and fluidically decoupled from the evaporator or the condenser via a heat exchanger and comprising a temperature-controlling element configured to be arranged in the space to be temperature-controlled and configured to be connected to the heat exchanger via a line arrangement comprising a secondary fluid that differs from the primary working fluid, wherein the line arrangement is suitable to penetrate the space limitation, wherein the secondary circuit is configured as a thermosiphon cycle, and wherein a controllable pump configured to reverse a conveying direction in the secondary circuit as a response to a control signal is arranged in the secondary circuit;

wherein the apparatus is configured to cool the space by means of the temperature-controlling element in a refrigeration mode; and

a controller configured to cause, as a response to a control signal, a heat pump cycle reversal in the primary heat pump circuit so that, in the refrigeration mode, energy is dissipated from the heat exchanger through the primary heat pump circuit, and so that, in a defrosting mode, energy is supplied to the heat exchanger through the primary heat pump circuit in order to defrost the temperature-controlling element, and the conveying direction in the secondary circuit is reversed by the controllable pump.

2. Apparatus according to claim 1, wherein the controller is configured to cause, via the control signal, the heat pump cycle reversal of the primary heat pump circuit such that the primary heat pump circuit's element that is coupled to the heat exchanger changes its function from evaporation to condensation or vice versa.

3. Apparatus according to claim 1, wherein the control signal originates from a sensor at the temperature-controlling element, from a sensor in the space to be temperature-controlled, or from a clock generator so that the apparatus is brought into the defrosting mode at regular or irregular points in time.

4. Apparatus according to claim 1, wherein the evaporator or the condenser of the primary heat pump circuit are configured to be integrated into the heat exchanger.

5. Apparatus according to claim 1, wherein the heat exchanger and the temperature-controlling element are arranged so as to be spaced apart by up to 50 meters, and wherein the controllable pump comprising an internal stator or an external stator is arranged in the line arrangement.

6. Apparatus according to claim 1, wherein the heat exchanger comprises a micro-channel heat exchanger, a plate heat exchanger, or a finned heat exchanger.

7. Apparatus according to claim 1, wherein the temperature-controlling element comprises a micro-channel heat exchanger, a plate heat exchanger, or a finned heat exchanger.

8. Apparatus according to claim 1, wherein the heat exchanger comprises a heat exchanger liquid space and a heat exchanger vapor space, and wherein the temperature-controlling element comprises a temperature-controlling vapor space and a temperature-controlling liquid space, wherein the heat exchanger and the temperature-controlling element are arranged with respect to each other such that vaporous secondary fluid may flow in a first region of the line arrangement between the heat exchanger vapor space and the temperature-controlling vapor space and liquid secondary fluid may flow in a second region of the line arrangement between the heat exchanger liquid space and the temperature-controlling liquid space.

9. Apparatus according to claim 1, wherein the temperature-controlling element is arranged with respect to the heat exchanger such that it is flooded by the secondary fluid, wherein, in the refrigeration mode, temperature-controlling is cooling and the heat exchanger is coupled to the evaporator of the primary heat pump circuit.

10. Apparatus according to claim 1, wherein the temperature-controlling element is elongated and comprises an oblique orientation with respect to a horizontal line, wherein the secondary fluid flows from top to bottom in its liquid state due to gravity or a pump force or a ventilator force or due to a heat exchanger arranged accordingly in the temperature-controlling element.

11. Apparatus according to claim 1, wherein the heat exchanger comprises:

a first connection portion for the primary working fluid;

a second connection portion for the primary working fluid;

a third connection portion for the secondary fluid;

a fourth connection portion for the secondary fluid;

a channel portion extending between the first connection portion for the primary working fluid and the second connection portion for the primary working fluid; and

an interaction region extending between the third connection portion for the secondary fluid and the fourth connection portion for the secondary fluid and having arranged therein the channel portion, wherein the channel portion is thermally coupled to the interaction region and fluidically decoupled from the interaction region.

12. Apparatus according to claim 1, wherein the compressor is configured in the primary heat pump circuit to be controllable so as to be reversed in its conveying direction by the control signal to cause the heat pump cycle reversal.

13. Apparatus according to claim 12, wherein the compressor comprises a conveyor wheel, wherein, for reversing the conveying direction, the compressor is configured to reverse a rotational direction of the conveyor wheel as a response to the control signal, or

wherein the compressor comprises a four-way valve, wherein, for reversing the conveying direction, the compressor is configured to, as a response to the control signal, on the basis of the refrigeration mode, fluidically decouple a suction side of the compressor from the evaporator or fluidically connect the same to the condenser, or fluidically decouple a pressure side of the compressor from the condenser and fluidically connect the same to the evaporator, or

wherein the compressor comprises a four-way valve, wherein, for reversing the conveying direction, the compressor is configured to, as a response to the control signal, on the basis of the defrosting mode, fluidically decouple a suction side of the compressor from the condenser and fluidically connect the same to the evaporator, or fluidically decouple a pressure side of the compressor from the evaporator and fluidically connect the same to the condenser.

14. Apparatus according to claim 1, further comprising:

a blower arranged in the space to be temperature-controlled within the space limitation so as to move air past the temperature-controlling element, or

a blower arranged outside of the space limitation so as to move air past the condenser of the primary heat pump circuit.

15. Apparatus according to claim 1, wherein the heat exchanger comprises the evaporator of the primary heat pump circuit or the condenser of the primary heat pump circuit and the heat exchanger for thermally coupling the primary heat pump circuit and the secondary heat pump circuit which are separated from each other by a line or which are arranged in one and the same space.

16. Space to be temperature-controlled, comprising:

a space limitation separating a space from a surrounding area of the space; and

an apparatus according to claim 1.

17. Space to be temperature-controlled according to claim 16, configured as a mobile transport container or as a space in a vehicle for being conveyed on water, on the road, on the rail, in the air, or in space.

18. Space to be temperature-controlled according to claim 16, configured as a space in a stationary building or as a free-standing stationary space.

19. Method for temperature-controlling a space to be temperature-controlled with a space limitation separating the space to be temperature-controlled from a surrounding area, with a primary heat pump circuit with an evaporator, a condenser, a compressor, and an expansion element, wherein the evaporator, the liquefier, the compressor, and the expansion element are arranged outside of the space to be temperature-controlled; and a secondary circuit thermally coupled to and fluidically decoupled from the evaporator or the condenser via a heat exchanger and comprising a temperature-controlling element arranged in the space to be temperature-controlled and connected to the heat exchanger via a line arrangement comprising a secondary fluid that differs from the primary working fluid, wherein the line arrangement penetrates the space limitation, wherein the secondary circuit is configured as a thermosiphon cycle, and wherein a controllable pump configured to reverse a conveying direction in the secondary circuit as a response to a control signal is arranged in the secondary circuit, comprising:

using, in the primary heat pump circuit, a natural primary working fluid;

using, in the line arrangement of the secondary circuit, a secondary fluid that differs from the primary working fluid,

wherein temperature-controlling in a refrigeration mode comprises cooling the space by means of the temperature-controlling element; and

as a response to the control signal, causing a heat pump cycle reversal in the primary heat pump circuit so that, in the refrigeration mode, energy is dissipated from the heat exchanger through the primary heat pump circuit, and so that, in a defrosting mode, energy is supplied to the heat exchanger through the primary heat pump circuit, in order to defrost the temperature-controlling element, and the conveying direction in the secondary circuit is reversed by the controllable pump.

20. Method for manufacturing an apparatus for temperature-controlling a space to be temperature-controlled with a space limitation separating the space to be temperature-controlled from a surrounding area, comprising: a primary heat pump circuit with an evaporator, a condenser, a compressor, and an expansion element, wherein the primary heat pump circuit comprises a natural primary working fluid, wherein the evaporator, the liquefier, the compressor, and the expansion element are arranged outside of the space to be temperature-controlled; a secondary circuit thermally coupled to and fluidically decoupled from the evaporator or the condenser via a heat exchanger and comprising a temperature-controlling element arranged in the space to be temperature-controlled and connected to the heat exchanger via a line arrangement comprising a secondary fluid that differs from the primary working fluid, wherein the line arrangement penetrates the space limitation, wherein the secondary circuit is configured as a thermosiphon cycle, and wherein a controllable pump configured to reverse a conveying direction in the secondary circuit as a response to a control signal is arranged in the secondary circuit, wherein, in a refrigeration mode, the apparatus is configured to cool the space by means of the temperature-controlling element, the method comprising:

introducing a natural primary working fluid into the primary heat pump circuit;

manufacturing a line arrangement that penetrates the space limitation;

introducing, into the line arrangement, a secondary fluid that differs from the primary working fluid; and

manufacturing a controller configured to cause, as a response to the control signal, a heat pump cycle reversal in the primary heat pump circuit so that, in the refrigeration mode, energy is dissipated from the heat exchanger through the primary heat pump circuit, and so that, in a defrosting mode, energy is supplied to the heat exchanger through the primary heat pump circuit so as to defrost the temperature-controlling element, and a conveying direction in the secondary circuit is reversed by means of the controllable pump.