EP3491303A1

EP3491303A1 - Heat pump system having heat pump assemblies coupled on the input side and output side

Info

Publication number: EP3491303A1
Application number: EP17746439.3A
Authority: EP
Inventors: Oliver Kniffler; Jürgen Süss
Original assignee: Efficient Energy GmbH
Current assignee: Efficient Energy GmbH
Priority date: 2016-07-26
Filing date: 2017-07-24
Publication date: 2019-06-05
Anticipated expiration: 2037-07-24
Also published as: EP3491303B1; CN109844423A; US20190154309A1; US11137172B2; WO2018019779A1; CN109844423B; DE102016213679A1

Abstract

The invention relates to a heat pump system comprising the following features: a first heat pump assembly (111) having a compressor (112) with a compressor output (113); a second heat pump assembly (114) having an input section (114a) and an output section (114b); and a coupler (115) for thermally coupling the first heat pump assembly (111) and the second heat pump assembly (114), wherein the coupler (115) has a first heat exchanger (115a) and a second heat exchanger (115b), wherein the first heat exchanger (115a) is connected to the input section (114a) of the second heat pump assembly (114), and wherein the second heat exchanger (115b) is connected to the output section (114b) of the second heat pump assembly (114).

Description

Heat pump system with input side and output side coupled heat pump assemblies

description

The present invention relates to heat pumps for cooling or for another application of a heat pump. Figures 8A and 8B illustrate a heat pump as described in European patent EP 20 6349 B1. FIG. 8A shows a heat pump, which initially has a water evaporator 10 for evaporating water as a refrigerant or cryogen to produce a steam in a working steam line 12 on the output side. The evaporator includes an evaporation space (not shown in FIG. 8A) and is configured to produce an evaporation pressure of less than 20 hPa in the evaporation space so that the water evaporates at temperatures below 15 ° C. in the evaporation space. The water is preferably groundwater, in the ground free or in collector pipes circulating brine, so water with a certain salinity, river water, seawater or seawater. Thus, all types of water, ie calcareous water, lime-free water, saline water or salt-free water can be used. This is because all types of water, that is all these "hydrogens", have the favorable water property that water, also known as "R 718", is an enthalpy differential useful for the heat pump process. Ratio of 6, which is more than 2 times the typical usable enthalpy difference ratio of z. B. R 134a corresponds.

The water vapor is supplied through the suction line 12 to a compressor / condenser system 14, which is a turbomachine such. B. has a radial compressor, for example in the form of a turbocompressor, which is designated in Fig. 8A with 16. The turbomachine is designed to compress the working steam to a vapor pressure at least greater than 25 hPa. 25 hPa corresponds to a liquefaction temperature of about 22 ° C., which may already be a sufficient heating flow temperature of a floor heating, at least on relatively warm days.To generate higher flow temperatures, pressures greater than 30 hPa can be generated with the flow machine 16, wherein a pressure of 30 hPa has a liquefaction temperature of 24 ° C, a pressure of 60 hPa has a liquefaction temperature of 36 ° C, and a pressure of 100 hPa corresponds to a liquefaction temperature of 45 ° C. Underfloor heating systems are designed to heat sufficiently with a flow temperature of 45 ° C, even on very cold days. The turbomachine is coupled to a condenser 18, which is designed to liquefy the compressed working steam. By liquefying the energy contained in the working steam is supplied to the condenser 18, to then be supplied via the flow 20a a heating system. The working fluid flows back into the condenser via the return line 20b.

It is possible to extract from the high-energy steam directly through the colder heating water, the heat (-energie), which is absorbed by the heating water, so that it heats up. The steam is so much energy withdrawn that this is liquefied and also participates in the heating circuit.

Thus, a material entry into the condenser or the heating system takes place, which is regulated by a drain 22, such that the condenser has a water level in its condenser, which remains despite the constant supply of water vapor and thus condensate always below a maximum level.

As already stated, an open circuit can be taken. So it can be evaporated directly without heat exchanger, the water, which is the heat source. Alternatively, however, the water to be evaporated could first be heated by a heat exchanger from an external heat source. However, it should be remembered that this heat exchanger again means losses and equipment expense.

In order to avoid losses for the second heat exchanger, which was previously necessarily present on the condenser side, the medium can also be used directly there. When thinking of a house with underfloor heating, the water coming from the evaporator can circulate directly in the underfloor heating.

Alternatively, however, on the condenser side, a heat exchanger can be arranged, which is fed with the flow 20a and having the return 20b, said heat exchanger cools the water in the condenser and thus heats a separate underfloor heating fluid, which will typically be water. Due to the fact that water is used as the working medium, and due to the fact that only the evaporated portion of the groundwater is fed into the turbomachine, the purity of the water does not matter. The flow machine, as well as the condenser and possibly directly coupled underfloor heating, are always supplied with distilled water in such a way that the system has a reduced maintenance compared to today's systems. In other words, the system is self-cleaning, since the system is always fed only distilled water and the water in the drain 22 is thus not polluted.

In addition, it should be noted that turbomachines have the properties that they - similar to an aircraft turbine - the compressed medium not with problematic substances, such as oil, in connection. Instead, the water vapor is compressed only by the turbine or the turbocompressor, but not associated with oil or other purity impairing medium and thus contaminated.

The distilled water discharged through the drain can therefore be returned to the groundwater without further ado, if no other regulations stand in the way. Alternatively, however, it may also be z. B. in the garden or in an open space to be seeped, or it can be supplied via the channel, if regulations dictate - a sewage treatment plant.

The combination of water as a working medium with a better than twice the usable enthalpy difference ratio compared to R 34a and because of the reduced system requirements (rather an open system is preferred), and due to The use of the turbomachine, which achieves the necessary compaction factors efficiently and without any impairment of purity, creates an efficient and environmentally neutral heat pump process, which becomes even more efficient when the liquefier directly liquefies the steam, since in the entire heat pump process there is not a single heat pump process Heat exchanger is needed more.

FIG. 8B shows a table for illustrating various pressures and the evaporation temperatures associated with these pressures, with the result that, in particular for water as the working medium, fairly low pressures are to be selected in the evaporator. In order to achieve a heat pump with a high efficiency, it is important that all components are designed low, ie the evaporator, the condenser and the compressor.

EP 2016349 B1 further shows that a condenser flow is used to accelerate the evaporation process so that the wall of a drain pipe acts as a nucleate for nucleate boiling. Furthermore, the process itself can also be used to increase the formation of bubbles. For this purpose, the condenser outlet is connected to a nozzle tube which has an end at one end and which has nozzle openings. The warm effluent water supplied from the condenser via the effluent at a rate of, for example, 4 ml per second is now fed to the evaporator. It is already vaporized on its way to a nozzle opening in the nozzle tube or directly at the outlet to a nozzle due to the too low for the temperature of the drain water pressure below the water surface of the evaporator water. The resulting vapor bubbles are directly as boiling nuclei for the evaporator water, which is conveyed through the inlet, act. This can be triggered without major additional measures an efficient bubble boiling in the evaporator.

DE 4431887 A1 discloses a heat pump system with a lightweight, large volume high performance centrifugal compressor. A vapor exiting a second stage compressor has a saturation temperature which exceeds the ambient temperature or that of available cooling water, thereby allowing for heat removal. The compressed vapor is transferred from the second stage compressor to the condenser unit, which consists of a packed bed provided within a cooling water sprayer at an upper surface supplied by a water circulating pump. The compressed water vapor rises in the condenser through the packed bed where it passes in direct countercurrent contact with the downwardly flowing cooling water. The vapor condenses and the latent heat of condensation absorbed by the cooling water is expelled to the atmosphere via the condensate and the cooling water, which are removed together from the system. The condenser is continuously purged with non-condensable gases by means of a vacuum pump via a pipeline. WO 2014072239 A1 discloses a condenser with a condensation zone for condensing vapor to be condensed in a working fluid. The condensation zone is formed as a volume zone and has a lateral boundary between the upper end of the condensation zone and the lower end. Further, the condenser comprises a steam introduction zone which extends along the lateral end of the condensation zone and is designed to supply condensing vapor laterally across the lateral boundary into the condensation zone. Thus, without increasing the volume of the condenser, the actual condensation is made into a volume condensation, because the vapor to be liquefied is introduced not only head-on from one side into a condensation volume or into the condensation zone, but laterally and preferably from all sides. This not only ensures that the condensation volume provided is increased with the same external dimensions compared to a direct countercurrent condensation, but that at the same time the efficiency of the condenser is improved because the vapor to be liquefied in the condensation zone is a transverse flow direction has the flow direction of the condensation liquid.

Commercial refrigeration systems, such as those used in supermarkets for keeping foodstuffs fresh and frozen, and foods are used in the colder regions now usually use C02 as a refrigerant. C02 is a natural refrigerant and is sub-critical with reasonable technical effort, ie at a liquefaction of the refrigerant below the critical point in two-phase area, as well at condensation temperatures below 30 ° C and also energetically advantageous over the previously used F-gas systems with fluorinated Hydrocarbons work. In Central Europe, C02 can not be used subcritically throughout the year, as high outdoor temperatures in the summer and occurring heat transfer losses do not permit subcritical operation. In order to ensure sufficient energetic process quality in supercritical operation in such a CO 2 refrigeration system, considerable technical effort is made. In supercritical operation, the heat dissipation of the process takes place at a pressure which is above the critical point. Therefore, one speaks of a gas cooling, since a liquefaction of the refrigerant is no longer possible. The gas cooler pressures increase to more than 100 bar in supercritical operation and the high pressure part of the C02-Kit plant including its heat exchanger must be dimensioned for these high pressures. Furthermore, larger and more powerful compressors or multiple compressors must be connected in parallel and / or in series. Finally, additional components such as collectors and ejectors are added Some of these are still in the concept development phase and should increase the efficiency of the plant in supercritical operation.

FIG. 9 shows a CO 2 cascade system 20. In such cascade systems with the refrigerant CO 2, C02 is used as refrigerant for the lower temperature stage 22, and for an upper temperature stage 24 refrigerants which have a high global warming potential, such as e.g. NH3, F-gases or hydrocarbons. The entire Rückkühlwärme the C02 process is taken here by the evaporator of the process of the upper temperature stage 24.

By the process of the upper temperature stage 24, the temperature level is then increased so that the heat can be discharged through the condenser to the environment. A sole operation of the C02 system is not possible with this interconnection and the refrigerant circuit of the upper temperature stage 24 is due to the component not able to realize any small temperature increases.

A further disadvantage of the concept described in FIG. 9 is the fact that the working media for the second heat pump stage have a high global warming potential. Another problem is the fact that the complete cooling capacity of the C02 circuit is transported by the cascade connection of the two heat pump arrangements in Fig. 9 from the NH3 cycle. As a result, it is necessary that the complete power provided by the first heat pump arrangement with CO 2 as the medium of the medium be re-used by the second heat pump arrangement with NH 3 as the working medium.

Therefore, as has already been stated, often, despite the problems with critical temperatures, the use of a one-stage CO 2 plant is set. This operates at very high pressures of over 60 bar. If a refrigeration system is considered in a supermarket, for example, this means that the heat removal, ie the refrigeration, takes place in the evaporator, which is placed, for example, in a technical room together with the compressor , However, the compressed CO 2 working gas is then passed through the entire supermarket in high-pressure lines on a recooler, which must also be high-pressure solid. There, energy is released from the compressed C02 gas to the environment, so that liquefaction takes place. The liquefied CO 2 gas, which is still under high pressure, will then typically recover via high-pressure lines from the recooler back into the plant room, where a relaxation takes place via a throttle, and the relaxed CO 2 working medium is recycled to the likewise under considerable pressure evaporator, where then again takes place evaporation to a C02 return from the cooling system of Refresh Supermarkets again.

The refrigeration technology is therefore relatively expensive, and not only with regard to the heat pump system in the technical room, but also due to the line technology through the supermarket and due to the recooler, which must be formed for very high pressures. On the other hand, this installation is advantageous in that C02 has only a low climatic efficiency compared to other media and at the same time, at least in manageable amounts, is non-toxic to humans.

The object of the present invention is to provide an improved heat pump system.

This object is achieved by a heat pump system according to claim 1 or a method for manufacturing a heat pump system according to claim 24 or by a method for operating a heat pump system according to claim 25.

According to the invention, at least one of the aforementioned disadvantages of the prior art is eliminated. In a first aspect, a C02 heat pump assembly is coupled to a heat pump assembly having water as the working medium. This coupling takes place via a coupler for thermal coupling of the two heat pump systems. The use of water as a working medium has several advantages. One advantage is that water does not require high pressures to operate in a heat pump cycle designed for the aforementioned temperatures. Instead, relatively low pressures take place, which, depending on the implementation, must only prevail within the heat pump arrangement running with water as the working medium, while a separate circuit can be readily used to recool a cooling system operating at other pressures and with others Working media can work as C02 or water. Another advantage is that with a heat pump arrangement that uses water as a working medium, with a limited amount of energy always safe can be set that the C02 heat pump assembly operates below the critical point. The temperatures required for this, below 30 ° C. or even below 25 ° C., can easily be provided by the second heat pump arrangement which operates with water. <br /><br/> Typically, for C02 heat pumps after the compressor, temperatures of perhaps 70 ° C. occur 70 ° C to eg 25 or 22 ° C is a temperature range that can be accomplished very efficiently with a heat pump that works with water as a working medium.

According to an alternative or additional aspect, the coupling of the second heat pump arrangement to the first heat pump arrangement takes place through the coupler for thermally coupling the two heat pump arrangements. Here, the coupler comprises a first heat exchanger and a second heat exchanger. The first heat exchanger is connected to the inlet section of the second heat pump arrangement, and the second heat exchanger is connected to the outlet section of the second heat pump arrangement.

Regardless of whether CO 2 is used as the working medium in the first heat pump assembly, and whether water is used as the working medium in the second heat pump assembly, this dual coupling results in significantly more efficient heat transfer from the first heat pump assembly to an environment, such heat transfer, for example is accomplished via another circuit with recooler. It is already achieved a temperature level reduction of the compressed working steam of the first heat pump assembly in the output side circuit of the second heat pump assembly. This initially cooled medium is then fed into the input-side circuit of the second heat pump arrangement, where it is finally cooled to the target temperature. This two-stage coupling leads, so to speak, to a self-regulation. Characterized in that the thermal coupler initially comprises the first heat exchanger, which is connected to the output circuit of the second heat pump assembly, a cooling of the compressed working medium of the first heat pump assembly takes place by a certain amount, for the second heat pump assembly still substantially no energy is expended got to. Only for the rest of the heat energy, which is not yet removed by the first heat exchanger, the second heat pump assembly must expend energy to bring about the input side heat exchanger of the second heat pump assembly then the working fluid of the first heat pump assembly to the target temperature. In implementations, the heat exchanger connected to the output section of the second heat pump assembly is additionally coupled to a recool, preferably via a third working medium circuit. Thus, a favorable working pressure can be selected for the recooler circuit, namely, for. As a relatively low pressure between 1 and 5 bar, and the medium in this cycle can be adapted to the specific needs, so z. B. have a water / glycol mixture, so as not to freeze in winter. At the same time, all health or constructively critical processes take place within the technical room of a supermarket, for example, without having to lay high-pressure pipes in the supermarket itself. In addition, all potentially hazardous substances are included only in the engine room when used for the first heat pump assembly and the second heat pump assembly or for one of the two heat pump assemblies problematic substances. These do not get out of the technical room out in a fluid circuit, the z. B. runs through the supermarket to the recooler and runs back from there.

In specific implementations, a heat pump assembly with a turbocompressor is used for the second heat pump assembly, which is operated for example with a radial wheel. By relatively infinitely variable adjustment of the rotational speed of the radial wheel, a cooling capacity of the second heat pump arrangement can be set, which automatically adapts precisely to the actual needs. Such an approach is with a conventional reciprocating compressor, such as. B. can be used in the first heat pump assembly, when CO 2 is used as the working medium, or if any other medium is used as the working medium, not readily available. In contrast, allows a heat pump assembly, which is virtually infinitely adjustable, such as a heat pump assembly with turbocompressor, which preferably has a radial wheel, an optimal and particularly efficient adaptation to the actually required refrigeration demand. For example, if the ambient temperature to which the recooler is coupled is so low that even the first heat pump system is sufficient and operated in the subcritical region in the case of CO 2, the second heat pump assembly will not need to generate refrigeration power in one embodiment, and hence none Consume electrical power. If, on the other hand, the outside temperatures in which the rear cooler is arranged are in an intermediate range, then an automatic displacement of the heat output required as a percentage of the second becomes due to the coupling Heat exchanger on the first heat exchanger, so take place on the input side of the second heat pump assembly. Depending on the design of the second heat pump arrangement, which can be operated as a multistage heat pump arrangement with or without free cooling mode, optimal adaptation always takes place, to the effect that the second heat pump arrangement always consumes only as much energy as is actually necessary is to support the first heat pump assembly and, for the example of C02, to drive in the subcritical range.

However, the shading on the input side and output side is not only useful for the combination of CO 2 as the working medium on the one hand and water as the working medium on the other hand, but also for any other applications in which other working media are used which can become supercritical in the required temperature ranges , In addition, the special coupling of a self-adapting second heat pump assembly with a first heat pump assembly is particularly advantageous when the first heat pump assembly is designed and constructed so that it is not or only roughly controllable, that works best and most efficient when they always generates the same amount of heat output. In an application in which this heat pump arrangement should actually produce variable heat output, an optimal coupling with the second heat pump arrangement takes place on the input side and on the output side, so that the second heat pump arrangement, which is finer than the first heat pump arrangement controllable and preferably infinitely variable or is controllable, always only has to spend the load that is actually necessary. The base load, or only roughly adjustable load, is thus provided by the first heat pump assembly, and the additional variable portion is variably controlled by the second heat pump assembly, regardless of whether the first heat pump assembly or the second heat pump assembly is CO2 or water Run working medium.

Preferably, a working fluid in the first heat pump assembly C02 or has a working fluid in the second heat pump assembly water. Further preferably, the working fluid in the first heat pump assembly C02 and has the working fluid in the second heat pump assembly water. Further preferably, the working fluid in the first heat pump assembly consists essentially of CO 2 and / or the working fluid in the second heat pump assembly consists essentially of water. Preferably, at least 90% and more preferably at least 98% or at least 99% of the working liquid of water or CO 2.

In addition, it should be noted that in a particularly preferred embodiment example! the first heat pump arrangement is operated with CO 2, the second heat pump arrangement is operated with water as the working medium, and the coupling of the two heat pump arrangements via the first and the second heat exchanger takes place, ie on the input side and on the output side. Preferred embodiments of the present invention will be explained below in detail with reference to the accompanying drawings. Show it:

1A is a block diagram of a heat pump system with a first heat pump arrangement with CO 2 and a second heat pump arrangement with water as the working medium according to a first aspect;

1 B is a heat pump system according to an alternative or additional second aspect, wherein the first heat pump assembly and the second heat pump assembly are coupled via a coupler having a first heat exchanger and a second heat exchanger.

Fig. 2A is a detailed illustration of a first heat pump arrangement;

Fig. 2B is a detailed view of a second heat pump assembly;

2C shows a block diagram of an embodiment with CO 2 as the first working medium and water as the second working medium and an input-side and output-side interconnection; Fig. 2D is a detailed illustration of the coupler for thermal coupling in conjunction with a condenser-side heat exchanger for a recooler circuit;

3A is a schematic representation of a heat pump system with chain-connected first and further heat pump stage. a schematic representation of two fixed-chain heat pump stages; a schematic representation of coupled with controllable directional switches in chain heat pump stages. a schematic representation of a controllable Wegemoduls with three

Inputs and three outputs; a table showing the various connections of the controllable road module for different modes of operation; a schematic representation of the heat pump system of Figure 4A with additional self-regulating liquid equalization between the heat pump stages. a schematic representation of the heat pump system with two stages, which is operated in the high performance mode (HLM); a schematic representation of the heat pump system with two stages, which is operated in the middle power mode (MKM); a schematic representation of the heat pump system with two stages, which is operated in free cooling mode (FKM); a schematic representation of the heat pump system with two stages, which is operated in low power mode (NLM); a table showing the states of various components in the various operating modes; a table showing the Betnebszustände the two coupled controllable 2x2-way switch; Fig. 7C is a table showing the temperature ranges for which the operation modes are appropriate; 7D is a schematic representation of the coarse / fine control over the operating modes on the one hand and the speed control on the other. 8A is a schematic representation of a known heat pump system with

Water as work equipment;

8B is a table showing various pressure / temperature situations for water as working fluid; and

9 shows a cascaded refrigeration system with C02 heat pump arrangement and NH3

Heat pump arrangement.

FIG. 1A shows a heat pump system according to a first aspect of the present invention including a first heat pump assembly 101 configured to operate with a first heat pump medium having CO 2. Further, the heat pump system includes a second heat pump assembly configured to operate with a second heat pump medium having water (H20). The second heat pump arrangement is designated by 102. The first heat pump assembly 101 and the second heat pump assembly 102 are coupled via a coupler 103 for thermally coupling the first heat pump assembly 101 and the second heat pump assembly 102.

The coupler can be configured as desired, for example as in the case of the heat exchanger of FIG. 9, in that the liquefier of the first heat pump arrangement 101 is coupled to the evaporator of the second heat pump arrangement 102 via a heat exchanger. Alternatively, depending on the implementation, another way of coupling may take place, eg an output-side coupling, to the effect that a compressor output of the first heat pump arrangement is coupled to a liquefier output of the second heat pump arrangement. In other embodiments, an input-side and an output-side coupling can be used, as shown for example in Fig. 1 B for any heat pump media. 1 B shows, according to a second aspect, a first heat pump arrangement 1 1 1, which has a compressor with a compressor outlet, wherein a compressor, for example at 1 12 is shown in Fig. 2A, and wherein the compressor output at 1 13 in Fig. 2A is shown. In addition, the heat pump system of Fig. 1B includes a second heat pump assembly 14 which has an input portion 14a and an output portion 14b. In addition, a coupler 15 is provided in order to couple the first heat pump arrangement 1111 and the second heat pump arrangement 114. In the aspect shown in FIG. 1B, the coupler 1 15 comprises a first heat exchanger 15a and a second heat exchanger 15b. The first heat exchanger 15a is connected to the inlet section 14a of the second heat pump arrangement. Furthermore, the second heat exchanger 15b is connected to the outlet section 14b of the second heat pump arrangement. In one implementation, the two heat exchangers 15a, 15b may also be interconnected, as shown at 15c.

FIG. 2A shows a more detailed illustration of the first heat pump arrangement 101 or 11. In particular, the first heat pump arrangement in the illustration shown in FIG. 2A comprises an evaporator 16 and a throttle 17. In a liquefaction process which will be described later, liquefied working fluid will become fed to the throttle 1 17, and its pressure level is brought to the lower pressure level at the entrance of the evaporator 1 16. The evaporator further comprises an evaporator inlet 1 16a, via which a working fluid to be cooled of the first heat pump arrangement is fed into the evaporator 16 1. Further, the evaporator 116 comprises an evaporator effluent 116b through which cooled working liquid from the evaporator 16 is brought into a region to be cooled, e.g. is a refrigerated area in a supermarket. Depending on the implementation of the evaporator inlet or inlet 1 16a and the evaporator outlet or outlet 1 16b be coupled directly to the area to be cooled or be coupled via a heat exchanger with a region to be cooled, so that, for the example of C02, the liquid C02 is not circulated directly in a cooling rack in corresponding lines, but via a heat exchanger another liquid medium cools, which then circulates in the corresponding lines of a refrigerated shelf or a freezer in a supermarket, for example.

FIG. 2B shows an implementation of a second heat pump assembly that includes an evaporator 120, a compressor 121, and a condenser 122. The evaporator 120 includes an evaporator inlet 120a and an evaporator outlet 120b. In addition, the condenser 122 includes a condenser inlet 122a and a condenser inlet 122a. liquid outlet 122b. At the evaporator-side end of the heat pump arrangement of FIG. 2B is the input section 1 14a, which is coupled to the first heat exchanger 15a of the coupler 15 of FIG. 1B. In addition, the condenser-side end of the second heat pump arrangement is shown by way of example in FIG. 2B to the right, the output section 1 14b. The condenser 122 and the evaporator 120 are also connected to one another via a throttle 123 to return liquefied working fluid back into the evaporator 120 bring to.

The second heat pump assembly further includes, in preferred embodiments, a controller 124 configured to detect a temperature in the input portion 14a and / or a temperature in the output portion 14b. For this, a detection in the evaporator inlet 120a, as shown at 124a, or a detection in the evaporator outlet 120b, as shown at 124b, a temperature detection in the condenser inlet 122a, as shown at 124c, or a temperature detection in the condenser, as it at 124d, take place. Depending on the sensed temperatures, the controller 124 is configured to control the compressor 121, which is preferably a turbocompressor having a radial wheel. For this purpose, in a single-stage second heat pump arrangement in the presence of a situation in which more cooling power is needed, the speed of the radial wheel in the compressor 121 is increased via a control line 125, or it will, as still with reference to Figures 3A-7D operating mode switching is made to switch from a low power mode (NLM), to a free cooling mode (FKM) with increasing power, to a mid power mode (MLM) and further increasing power to a high power mode (HLM) and respectively vice versa, as shown with reference to FIG. 7D and will be explained later.

Fig. 2C shows a heat pump system in which 1 1 CO 2 is used as the working medium in the first heat pump assembly 101/1, while in the second heat pump assembly 102/1 14 water is used as the working medium. Water is also called R718 in heat pump technology.

The first heat pump system 101/1 1 1, which is referred to as "CO 2 refrigeration system" in Fig. 2C, is thermally coupled via a coupler to the second heat pump system 102/1 14. In the embodiment shown in Fig. 2C, the coupler is made the first heat exchanger 15a and the second heat exchanger 15b. In addition, in the preferred embodiment shown in FIG. 2C, a third circuit is provided, which has an output-side heat exchanger 130 and a recooler 131. The recooler 131 is disposed on the roof or on the north side in the shadow of the supermarket building in the exemplary application scenario where a supermarket is viewed. There, a fan is typically arranged, which blows a liquid-to-air heat exchanger in order to achieve a good heat transfer from the recooler 131 into the environment.

Fig. 2C shows exemplary temperatures. A C02 gas that has been compressed and is, for example, at a pressure of 70 bar and a temperature of 70 ° C, is fed into the second heat exchanger 15b. Exemplary output-side temperatures of the second heat exchanger 15b are in the range of perhaps 48 ° C. Via a connecting line between the second heat exchanger 15b and the first heat exchanger 15a, which is designated 15c in FIG. 2C and FIG. 1B, the already cooled but still gaseous CO2 flows into the first heat exchanger 15a, where it is then output at a temperature of about 22 ° C. This means that an actual liquefaction of the CO 2 gas takes place only in the first heat exchanger 15a at the operating temperatures shown in FIG. 2C, whereas in the second heat exchanger 15b a cooling of the gas already takes place above 20 ° C.

In the second heat pump assembly 102/1 14, water is used as the medium. The separation of the water cycle to the outside is the input side through the first heat exchanger 1 15a and the output side by the other heat exchanger 130 instead. This makes it possible for another pressure to be used in the third circuit or the recooler circuit again, namely a pressure which can be handled well between 1 and 5 bar. Further, as the medium in the third cycle, preferably a water / glyco-mixture is used. The output of the second heat exchanger 1 15 b on the secondary side of the heat exchanger 1 15 b is connected to an input 131 a of the rear cooler 131. The output of the recooler, which is due to the heat transfer to the environment only at a temperature of for example 40 ° C and drawn at 131 b, passes through the further heat exchanger 130 in a secondary-side input of the second heat exchanger 1 15b. The circulating in the recooler liquid medium is brought in the heat exchanger 130 to a temperature of for example 46 ° C due to the waste heat of the second heat pump assembly. Here, for example, the condenser 22 of FIG. 2B, which is not shown separately in FIG. 2C, is coupled to the further heat exchanger 130. Alternatively and with reference to FIGS. 6A to 6D, The heat exchanger 130 in Fig. 2C is the heat exchanger WTW 214 of Figs. 6A to 6D.

Thus, the recooler circuit is supplied both by the second heat pump assembly 102/1 14 and by the first heat pump assembly 101/1 1 1 with waste heat.

FIG. 2D shows a more detailed illustration of the heat exchangers of FIGS. 1B and 2C. The first heat exchanger comprises a primary side with a primary-side inlet 15c and a primary-side outlet 132. In addition, the secondary side of the first heat exchanger 15a is connected to the evaporator of a single-stage heat pump or with respective switching on an input side of the heat pump to the various modes , as shown in Figs. 6A to 6D, to perform. The input section of the second heat pump arrangement thus comprises, in the case of a single-stage heat pump, in which only the speed of the compressor is controllable, but no mode switching is achievable, the evaporator outlet 120b and the evaporator inlet 120a, as shown in Fig. 2D. However, if a preferably two-stage heat pump assembly is used, which has a first stage and a second stage, and which, for example, in two or more and z. For example, as shown in FIGS. 7A-7D, the input section may include those having the "WTK" or "Heat Exchanger Cold" which is 212 in FIGS. 6A-6D Further, the output section then includes the lines 402, 340 connected to the "WTW" and "heat exchanger hot", respectively, labeled 214 in Figs. 6A-6D.

In particular, in a preferred implementation of the cold heat exchanger 212 in FIGS. 6A-6D, the heat exchanger 15a of FIG. 2D is shown, and the second heat exchanger "WTW" 214 of FIGS. 6A-6D constitutes the further heat exchanger 130 of FIG. 2D dar.

However, in one implementation, another heat exchanger may readily be disposed between the heat exchanger WTK 212 of FIGS. 6A-6D and the first heat exchanger 15a, or another heat exchanger may be disposed between the heat exchanger WTW 214 of FIGS. 6A-6D and the further heat exchanger 130 may be arranged to the inner heat pump assembly of the first heat exchanger and / or the further heat exchanger or the third circuit between the further heat exchanger 130 and the recooler 131 of Fig. 2C further decouple.

This means that the evaporator outlet 120b and the evaporator inlet 120a need not necessarily be connected to the first heat exchanger, but alternatively, the lines 401, 230 of FIGS. 6A to 6D, which correspond to the position of the switches 421, 422, respectively Connections / other lines are connected to achieve different operating modes. Analogously, the output section 1 14b of the second heat pump arrangement is formed. The output section need not necessarily be connected to the condenser inlet and the condenser outlet, but may be connected to the lines 402, 340 of FIGS. 6A to 6D, which are then coupled to corresponding other components depending on the state / switching mode via the switches 421, 422 as shown in FIGS. 6A to 6D.

In addition, the second heat exchanger 1 15b also comprises a primary side with a primary input 1 13, which is preferably coupled to the compressor output 1 13 of the first heat pump assembly, and a primary-side output 15 c, which is coupled to a primary-side input of the first heat exchanger 1 15 a.

The secondary side of the second heat exchanger comprises a secondary-side inlet 134, which is coupled to a primary-side outlet of the further heat exchanger 130. The secondary-side output 131 a of the second heat exchanger 1 15 b in turn is connected to an input 131 a of the recooler 131. The outlet 131b of the rear cooler is in turn connected to the primary-side inlet of the further heat exchanger 130, as shown in FIG. 2D.

As has already been explained, the heat pump systems according to the invention achieve according to the two aspects that, in particular, a refrigeration system, ie a heat pump system for cooling, is made structurally as simple as possible, that the disadvantages of environmental damage, the danger, the power efficiency or the apparatus construction be at least partially eliminated individually or in combination. For this purpose, a refrigeration system according to the first aspect with respect to the cascading of CO 2 and water is used, or a heat pump system according to the second aspect, in which an input and output side coupling of two heat pump stages, which are operated with any working media, is achieved, preferably both Aspects can be used in combination, ie that the coupling of the C02 heat pump and the water heat pump takes place via an input-side and output-side heat exchanger.

Embodiments of the present invention achieve that an efficient operation of the CO 2 refrigeration system is achieved at high ambient temperatures of, for example, above 30 ° C., and unlike the prior art proposed, no technically complex solutions are necessary. Instead, at low outside temperatures an inexpensive pre-cooling is used. For this purpose, according to one aspect, the C02 refrigeration system for heat dissipation is thermally coupled with a cooling system with water as the refrigerant. The C02 refrigeration system is thermally coupled to the refrigeration system by means of a heat exchanger. As a result, in a structurally simple manner, a heat dissipation from the C02 refrigeration system and thus an effective pre-cooling can be achieved.

This ensures that condensation temperatures can always be reduced below 25 ° C, so that the C02 process is subcritical all year round, and thus simultaneously realized efficiently. Technically complex solutions, such as additional or powerful compressors or other, the C02 refrigeration complicating components can be omitted and the recooling of the entire system is carried out all year at a pressure, as in such systems usually in the recooling circuit with water or in a water - Recirculation mixture, depending on the temperature of the installation, prevails. The entire system can be realized so compact and with a low C02-Füllmenge.

This solution results in a compact overall system, in which the entire heat of recooling is discharged via a water or water-brine mixture to the environment. Cooler of the C02 process consists of the two heat exchangers 1 15a, 1 15b, wherein at low outside temperatures, the entire Rückkühlieistungen first by C02 flowed heat exchanger, ie the second heat exchanger 1 15b is transferred to the recooling circuit with the recooler 131 of FIG. 2C, for example. With rising temperatures in Rückkühikreislauf is also in the first heat exchanger, ie the first heat exchanger 1 15a, which is coupled to the second heat pump assembly 102/1 14 for pre-cooling, released heat from the C02 cycle, so that a temperature of for example 22 ° C behind the first Heat exchanger is never exceeded, as it is exemplified in Fig. 2C.

With increasing temperature in the recooling circuit, the recooling power shifts from the second through-flow heat exchanger to the first. At temperatures in the recooling circuit, which make it possible to reach the 22 ° C temperature already after the second heat transfer, the second heat pump stage 102/114 switches off completely for precooling. This means that it is always possible by the inclusion of precooling proposed here to operate the entire system energetically optimal with minimal energy consumption. In preferred embodiments, it is provided to thermally couple the cooling system via the thermal coupler, and in particular via the second heat exchanger 1 15b with the compressor of the CO 2 refrigeration system, such that the compressed and thus overheated CO 2 vapor of the first heat pump system is cooled and finally, for example, is liquefied by the heat exchanger 1 15a of Fig. 2C.

Compared to the standard process, after the CO 2 compressor stage, for example stage 1 12 of FIG. 2C, the superheated steam is thus pre-cooled. At high outdoor temperatures, such as occur in the summer, about 50% of the Rückkühlwärme the CO 2 process as heat of dehiscence to the water or water / glycol circuit in which the recooler 131 is disposed, discharged, and to the heat sink, so for example, given the environment. The recooling capacity of the proposed refrigeration system can be parallel to or before the feed through the C02 process.

If the temperatures drop in the water / glycol cycle due to the weather, the discharged recooling or desuperheating performance of the CO 2 process in the pre-cooling increases and the required power of the first heat pump arrangement increases. Accordingly, the temperature supply between the heat-absorbing and the heat-emitting side of the refrigerator also decreases. For this purpose, the use of turbocompressors, as illustrated, for example, at 121 in FIG. 2B, is particularly advantageous, since the rotational speed simultaneously influences the cooling power and the pressure / temperature stroke. With increasing speed, both power and temperature increase increase. In order to be able to use the advantages of turbo compression in the area of pre-cooling for smaller cooling capacities, ie for cooling capacities between 30 kW and 300 kW, the refrigerant water (R 718) is ideally suited. Due to the low volumetric cooling capacity, the use of turbomachines is possible even with smaller outputs below 50 kW. The second heat pump arrangement is preferably designed to deliver heat outputs of less than 100 kW.

2C schematically shows the second heat pump stage 102/1 14 as pre-cooling, which is designed as a refrigeration system which uses water as the refrigerant. Preferably, for example, the eChiller from Efficient Energy GmbH is used as the refrigeration system. The eChiller used in one expansion stage has a maximum cooling capacity of 40 kW and, when introduced into the C02 process to dissipate the heat of condensation, enables a CO 2 process that can be operated subcritically throughout the year and a total recooling capacity of up to 80 kW Has. Higher performance can be achieved by parallel connection of several refrigeration units for pre-cooling. For thermal coupling of the refrigeration system 102/1 14 to the CO 2 refrigeration system 101/1 1 1, the heat exchanger or thermal coupler 1 15 is provided, which comprises the first heat exchanger 1 15a and the second heat exchanger 1 15b, which preferably with the compressor 1 12 of the C02 refrigeration system is coupled. This pre-cools the superheated steam from the C02 process. The present invention according to the described embodiment is advantageous in that heat recovery is also easy to realize in that the heat of dewatering of the CO 2 process is not released via the recooler 131 via the environment, but is discharged into a Nutz-heat sink. In this case, the recooler would be arranged in an environment in which the waste heat is usefully used.

In the following, reference is made to FIGS. 3A-7D, which show a two-stage or multi-stage heat pump arrangement, as implemented, for example, in the eChiller. In the following description of the figures, the second heat pump arrangement from FIGS. 1 A to 2 C is also referred to as a heat pump system.

Fig. 3A shows such a heat pump system, wherein the heat pump system or second heat pump assembly 102, 1 14 may have any arrangement of pumps or heat exchangers. In particular, a heat pump installation, as shown in FIG. 3A, comprises a heat pump stage 200, ie stage n + 1 with a first evaporator 202, a first compressor 204 and a first condenser 206, the evaporator 202 above the steam duct 250 with the first Compressor 204 is coupled, and as soon as the compressor 204 is coupled via the steam channel 251 with the condenser 206. It is preferred to use the entangled arrangement again, but any arrangements in the heat pump stage 200 may be used. Depending on the implementation, the inlet 222 into the evaporator 202 and the outlet 220 from the evaporator 202 are either with an area to be cooled or with a heat exchanger, such as the heat exchanger 212 to the area to be cooled or with another pre-arranged heat pump stage, for example the heat pump stage n connected, where n is an integer greater than or equal to zero.

In addition, the heat pump system in Fig. 3A comprises another heat pump stage 300, i. the stage n + 2, with a second evaporator 302, a second compressor 304 and a second condenser 306. In particular, the output 224 of the first condenser is connected to an evaporator inlet 322 of the second evaporator 320 via a connecting line 332. The output 320 of the evaporator 302 of the further heat pump stage 300 may be connected to the inlet to the condenser 206 of the first heat pump stage 200 as shown by a dashed connection line 334, as implemented. However, as shown with reference to FIGS. 4A, 6A through 6D and 5, the output 320 of the evaporator 302 may also be connected to a controllable path module to achieve alternative implementations. In general, however, a derailleur circuit is achieved due to the fixed connection of the condenser outlet 224 of the first heat pump stage with the evaporator inlet 322 of the further heat pump stage.

This derailleur ensures that each heat pump stage must work with the lowest possible temperature spread, so with the smallest possible difference between the heated working fluid and the cooled working fluid. By connecting in series, so by a chain circuit such heat pump stages is thus achieved that nevertheless a sufficiently large total spread is achieved. The total spread is thus divided into several individual spreads. The derailleur is particularly advantageous because it allows much more efficient operation. The consumption of compressor power for two stages, each of which has to cope with a smaller temperature spread, is smaller than the compression ratio. for a single heat pump stage, which must reach a high temperature spread. In addition, the requirements for the individual components with two stages connected in chain are technically more relaxed. As shown in FIG. 3A, the condenser exit 324 of the condenser 306 of the further heat pump stage 300 may be coupled to the area to be warmed, as illustrated by heat exchanger 214, for example, with reference to FIG. 3B. Alternatively, however, the output 324 of the condenser 306 of the second heat pump stage can again be coupled via a connecting tube to an evaporator of a further heat pump stage, that is to say the (n + 3) heat pump stage. Thus, depending on the implementation, FIG. 3A shows a chain circuit of, for example, four heat pump stages when n = 1 is taken. However, if n is taken arbitrarily, Fig. 3A shows a chain circuit of any number of heat pump stages, in particular the chain circuit of the heat pump stage (n + 1), which is denoted by 200, and the other heat pump stage 300, with (n + 2 ) is described in more detail and the n- heat pump stage as well as the (n + 3) - heat pump stage can not be designed as a heat pump stage, but each as a heat exchanger or as to be cooled or heated area. Preferably, as shown in FIG. 3B, for example, the condenser of the first heat pump stage 200 is disposed above the evaporator 302 of the second heat pump stage, so that the working fluid flows through the connection line 332 due to gravity. In particular, in the specific implementation of the individual heat pump stages shown in FIG. 3B, the condenser is arranged above the evaporator anyway. This implementation is particularly advantageous because even with heat pump stages aligned with each other, the liquid already flows from the first stage condenser into the second stage evaporator through the connection line 332. In addition, however, it is preferred to achieve a height difference that includes at least 5 cm between the top of the first stage and the top of the second stage. However, this dimension, shown at 340 in FIG. 3B, is preferably 20 cm, since then, for the described implementation, optimal water flow from the first stage 200 to the second stage 300 via the connection line 332 occurs. This also ensures that in the connecting line 332 no special pump is needed. This pump is therefore saved. Only the intermediate circuit pump 330 is required to return the working fluid from the outlet 320 of the second stage evaporator 300, which is lower than the first stage Condenser of the first stage, that is to bring in the input 226. For this purpose, the output 320 is connected via the pipe 334 to the suction side of the pump 330. The pump side of the pump 330 is connected via the tube 336 to the inlet 226 of the condenser. The chain circuit of the two stages shown in Fig. 3B corresponds to Fig. 3A with the connection 334. Preferably, the intermediate circuit pump 330 is also like the other two pumps 208 and 210 arranged below, since then in the intermediate circuit 334 cavitation can be prevented because due to the placement of the intermediate circuit pump 330 in the downpipe 334 a sufficient back pressure of the pump is achieved.

Although the configuration according to the first aspect is shown in FIG. 3B, that is to say that the heat exchangers 212, 214 are arranged below the pumps 208, 210 and 330, the arrangement of the pumps 208, 210 next to the heat exchangers 212, 214 can also be used. as set forth in the second aspect.

As shown in FIG. 3B, the first stage comprises the expansion element 207 and the second stage comprises an expansion element 307. However, since working fluid exits the first stage condenser 206 via the connection line 332, the expansion element 207 is dispensable. In contrast, the expansion element 307 in the lower stage is preferably used. Thus, in one embodiment, the first stage may be constructed without an expansion element and only one expansion element 307 is provided in the second stage. However, since it is preferable to make all stages the same, the expansion element 207 is also provided in the heat pump stage 200. When implemented to aid in bubble boiling, the expansion element 207 is also helpful despite the fact that it may not deliver liquefied working fluid into the evaporator, but only heated steam.

Nevertheless, it has been found that in the arrangement shown in FIG. 3B, working fluid accumulates in the evaporator 302 of the second heat pump stage 300. Therefore, as shown in FIG. 5, a measure is taken to bring working fluid from the evaporator 302 of the second heat pump stage 300 into the first stage evaporator circuit 200. For this purpose, an overflow arrangement 502 is arranged in the second evaporator 302 of the second heat pump stage in order to carry away working fluid from a predefined maximum working fluid level in the second evaporator 302. Furthermore, a liquid line 504, 506, 508 is provided. hen, which is coupled on the one hand with the overflow arrangement 502, and on the other hand coupled to a suction side of the first pump 208 at a coupling point 512. At the coupling point 512, a pressure reducer 510 is present, which is preferably designed as a pressure reducer to Bernoulli, so as a pipe or Schlauchengstelle. The fluid conduit comprises a first connecting portion 504, a U-shaped portion 506 and a second connecting portion 508. Preferably, the U-shaped portion 506 has a vertical height in the operating position that is at least 5 cm and preferably 15 cm. This provides a self-regulating system that operates without a pump. If the water level in the evaporator 302 of the lower container 300 is too high, working fluid will flow into the U-tube 506 via the connecting line 504. The U-tube is coupled to the suction side of the pump 208 via the connecting line 508 at the coupling point 512 at the pressure reducer. Due to the increased flow rate in front of the pump due to the constriction 510, the pressure drops and water from the U-tube 506 can be absorbed. In the U-tube, a stable water level is established, which is sufficient for the pressure in front of the pump in the constriction and in the evaporator of the lower tank. At the same time, however, the U-tube 506 is a vapor barrier, in that no vapor from the evaporator 302 can enter the suction side of the pump 208. The expansion elements 207 and 307 are preferably also designed as overflow arrangements, in order to bring working fluid into the respective evaporator when a predetermined level in a respective condenser is exceeded. Thus, the levels of all containers, so all condenser and evaporator in both heat pump stages automatically, without effort and without pumps but set self-regulating. This is particularly advantageous because it allows heat pump stages to be run or shut down depending on the operating mode.

Figures 4A and 5 already show a detailed illustration of a steerable routing module due to the upper 2x2 way switch 421 and the lower 2x2 way switch 422. Figure 4B shows an overall implementation of the steerable routing module 420 passing through the two serially connected ones 2x2-way switches 421 and 422 may be implemented, but which may alternatively be implemented.

The controllable path module 420 of FIG. 4B is coupled to a controller 430 to be controlled by it via a control line 431. The controller receives sensor signals 432 as input signals and supplies pump control signals on the output side 436 and / or compressor motor control signals 434. The compressor motor control signals 434 lead to the compressor motors 204, 304 as shown in FIG. 4A, for example, and the pump control signals 436 lead to the pumps 208, 210, 330. Depending on the implementation, the pumps 208, However, 210 fixed, that is run uncontrolled, because they run anyway in each of the operating modes described with reference to FIGS. 7A, 7B. Only the intermediate circuit pump 330 could therefore be controlled by a pump control signal 436.

The controllable path module 420 comprises a first input 401, a second input 402 and a third input 403. As shown, for example, in FIG. 4A, the first input 401 is connected to the outlet 241 of the first heat exchanger 212. In addition, the second input 402 of the controllable path module is connected to the return or outlet 243 of the second heat exchanger 214. In addition, the third input 403 of the controllable path module 420 is connected to a pump side of the intermediate circuit pump 330.

A first output 41 1 of the controllable path module 420 is coupled to an input 222 in the first heat pump stage 200. A second output 412 of the controllable path module 420 is connected to an input 226 in the condenser 206 of the first heat pump stage. In addition, a third output 413 of the controllable path module 420 is connected to the input 326 in the condenser 306 of the second heat pump stage 300.

The various input / output connections achieved by the controllable path module 420 are shown in FIG. 4C.

In a high performance mode (HLM) mode, the first input 401 is connected to the first output 41 1. Furthermore, the second input 402 is connected to the third output 413. In addition, the third input 403 is connected to the second output 412, as shown in line 451 of FIG. 4C.

In the mid-power mode (MLM) where only the first stage is active and the second stage is inactive, that is, the second stage compressor motor 304 is off, the first input 401 is connected to the first output 41 1. Furthermore, the second input 402 is connected to the second output 412. In addition, the third input 403 is connected to the third output 413, as shown in line 452. Line 453 shows the free cooling mode in which the first input is connected to the second output, so the input 401 to the output 412. In addition, the second input 402 is connected to the first output 41 1. Finally, the third input 403 is connected to the third output 413.

In low power mode (NLM), shown at line 454, the first input 401 is connected to the third output 413. In addition, the second input 402 is connected to the first output 41 1. Finally, the third input 403 is connected to the second output 412.

It is preferred to implement the controllable path module through the two serially arranged 2-way switches 421 and 422, as e.g. are shown in Fig. 4A, or as they are also shown in Figs. 6A to 6D. Here, the first 2-way switch 421 has the first input 401, the second input 402, the first output 41 1 and a second output 414, which is coupled via an interconnect 406 to an input 404 of the second 2-way switch 422 , The 2-way switch has the third input 403 as an additional input and the second output 412 as an output and the third output 413 also as an output. The positions of the two 2x2-way switches 421 are shown in tabular form in FIG. 7B. Fig. 6A shows the two positions of the switches 421, 422 in the high power mode (HLM). This corresponds to the first line in FIG. 7B. Fig. 6B shows the position of the two switches in the mid-power mode. The upper switch 421 is exactly the same in the mid-power mode as it is in the high-power mode. Only the lower switch 422 has been switched. In the free cooling mode illustrated in FIG. 6C, the bottom switch is the same as in the mid-power mode. Only the upper switch has been switched. Finally, in the low power mode, the lower switch 422 is switched compared to the free cooling mode, while the lower power switch is equal to its free cooling mode position. This ensures that only one switch needs to be switched from one neighboring mode to the next mode, while the other switch can remain in its position. This simplifies the entire switching action from one operating mode to the next.

Fig. 7A shows the activities of the individual compressor motors and pumps in the various modes. In all modes, the first pump 208 and the second pump 210 are active. tively. The DC link pump is active in the high power mode, the mid power mode, and the free cooling mode, but is deactivated in the low power mode.

The first stage compressor motor 204 is active in high power mode, mid power mode, and free cooling mode, and is deactivated in low power mode. In addition, the second stage compressor motor is only active in high power mode but disabled in mid power mode, free cooling mode and low power mode. It should be noted that FIG. 4A illustrates the low power mode in which the two motors 204, 304 are deactivated, and in which the intermediate circuit pump 330 is also activated. In contrast, Fig. 3B shows the to some extent coupled high performance mode in which both motors and all pumps are active. FIG. 5 again shows the high-performance mode, in which the switching positions are such that exactly the configuration according to FIG. 3B is obtained.

FIGS. 6A and 6C also show various temperature sensors. A sensor 602 measures the temperature at the outlet of the first heat exchanger 212, ie at the return from the side to be cooled. A second sensor 604 measures the temperature at the return of the side to be heated, ie from the second heat exchanger 214. Further, another temperature sensor 606 measures the temperature at the outlet 220 of the first stage evaporator, which temperature is typically the coldest temperature. In addition, a further temperature sensor 608 is provided which measures the temperature in the connection line 332, that is, at the output of the first stage condenser, indicated 224 in other figures. In addition, the temperature sensor 610 measures the temperature at the outlet of the second stage evaporator 300, that is, at the outlet 320 of FIG. 3B, for example.

Finally, the temperature sensor 612 measures the temperature at the output 324 of the second stage condenser 306, which temperature in full power mode is the warmest temperature in the system. Hereinafter, referring to FIGS. 7C and 7D, the various stages or operating modes of the heat pump system, as shown for example with reference to FIGS. 6A to 6D, and is also illustrated with reference to the other figures. DE 10 2012 208 174 A1 discloses a heat pump with a free cooling mode. In the free cooling mode, the evaporator inlet is connected to a return from the area to be heated. Further, the condenser inlet is connected to a return from the area to be cooled. The free cooling mode already achieves a considerable increase in efficiency, in particular for outside temperatures lower than, for example, 22 ° C.

This free cooling mode or (FKM) is shown at line 453 in FIG. 4C and is particularly shown in FIG. 6C. In particular, the output of the cold side heat exchanger is connected to the input to the first stage condenser. Moreover, the output from the heat-side heat exchanger 214 is coupled to the first-stage evaporator inlet, and the input to the heat-side heat exchanger 214 is connected to the second-stage condenser outlet 300. However, the second stage is disabled so that the condenser drain 338 of FIG. 6C has the same temperature as the condenser inlet 413, for example. Moreover, the second stage evaporator effluent 334 has the same temperature as the second stage condenser inlet 413, so that the second stage 300 is thermodynamically "shorted." However, although the compressor motor is deactivated, this stage is traversed by working fluid Stage is therefore still used as infrastructure, but is disabled due to the compressor motor switched off.

If, for example, switching from the mid-power mode to the high-power mode, ie from a mode in which the second stage is deactivated and the first stage active, to a mode in which both stages are active, it is preferred, first of all, to use the compressor motor a certain time, which is, for example, greater than one minute, and preferably 5 minutes, to run before then the switch 422 is switched from the switch position shown in Fig. 6B to the switch position shown in Fig. 6A. A heat pump in the second heat pump arrangement 102/1 14 comprises an evaporator with an evaporator inlet and an evaporator outlet, as well as an evaporator outlet. liquid with a condenser inlet and a condenser outlet. In addition, a switching device is provided to operate the heat pump in an operating mode or other operating mode. In one operating mode, the low-power mode, the heat pump is completely bypassed, in that the return of the area to be cooled is connected directly to the trace of the area to be heated. In addition, in this lock-up mode or low-power mode, the return of the area to be heated is connected to the trace of the area to be cooled. Typically, the evaporator is assigned to the area to be cooled and the condenser is assigned to the area to be heated.

In the bridging mode, however, the evaporator is not connected to the area to be cooled, and furthermore the condenser is not connected to the area to be cooled, but both areas are to a certain extent "short-circuited." In the second alternative operating mode, however, the heat pump is not bridged but, at relatively low temperatures, is typically operated in the free-cooling mode or in normal mode with one or two stages In the free-cooling mode, the switching means is arranged to connect a return of the area to be cooled with the condenser inlet and a return In contrast, the switching device is designed in the normal mode to connect the return of the area to be cooled with the evaporator inlet and to connect the return of the area to be heated with the condenser inlet of the warming area with the evaporator inlet.

Depending on the embodiment, a heat exchanger may be provided at the output of the heat pump, that is, on the condenser side, or at the inlet of the heat pump, ie on the evaporator side, to decouple the inner heat pump cycle from the outer circuit in terms of liquid. In this case, the evaporator inlet is the inlet of the heat exchanger coupled to the evaporator. Moreover, in this case, the evaporator outlet constitutes the outlet of the heat exchanger, which in turn is coupled to the evaporator.

Similarly, at the condenser side, the condenser outlet is a heat exchanger outlet, and the condenser inlet is a heat exchanger inlet, on the side of the heat exchanger that is not coupled to the actual condenser. Alternatively, however, the heat pump can be operated without input-side or output-side heat exchanger. Then, for example, a heat exchanger could be provided at the entrance to the area to be cooled or at the entrance to the area to be heated, which then comprises the return or trace to the cooling area or to the area to be heated.

In preferred embodiments, the heat pump is used for cooling, so that the area to be cooled is, for example, a room of a building, a computer room or generally a refrigerator or a supermarket, while the area to be heated is e.g. is a roof of a building or similar location where a heat dissipation device can be placed to deliver heat to the environment. However, if the heat pump is alternatively used for heating, the area to be cooled is the environment from which energy is to be extracted and the area to be heated is the "utility", such as the interior of a building, a house or a room to be tempered.

The heat pump is thus capable of switching from the bypass mode to either the free cooling mode or, if such free cooling mode is not established, to the normal mode.

In general, the heat pump is advantageous in that it becomes particularly efficient when outside temperatures are present, e.g. less than 16 ° C, which is often the case at least in the northern and southern hemispheres distant from the equator.

This ensures that outside temperatures, where direct cooling is possible, the heat pump can be completely taken out of service. In the case of a heat pump with a radial compressor between the evaporator and the condenser, the radial wheel can be stopped and no energy needs to be put into the heat pump. Alternatively, however, the heat pump may still be in a standby mode or the like, but since it is only a standby mode, it will consume only a small amount of power. Especially with valveless heat pumps, as they are preferably used, a thermal short circuit can be avoided by complete bridging of the heat pump in contrast to the free cooling mode. In addition, it is preferred that the switching means in the first operating mode, ie in the low-power or bypass mode, the return of the cooled Area or the trace of the area to be cooled from the evaporator completely separates, so that no fluid connection between the inlet or outlet of the evaporator and the area to be cooled longer exists. This complete separation will also be beneficial on the condenser side.

In implementations, a temperature sensing device is provided that senses a first temperature with respect to the evaporator or a second temperature with respect to the condenser. Furthermore, the heat pump has a controller, which is coupled to the temperature sensor device and is designed to control the switching device depending on one or more temperatures detected in the heat pump, so that the switching device switches from the first to the second operating mode or vice versa. The implementation of the switching means may be implemented by an input switch and an output switch, each having four inputs and four outputs, and switchable according to the mode. Alternatively, however, the switching device can also be implemented by a plurality of individual cascaded switches, each having an input and two outputs.

Furthermore, as a coupling element for coupling the bridging line with the approach to the area to be heated or the coupler for coupling the bridging line with the Hinlauf in the area to be cooled may be formed as a simple three-port combination, ie as a liquid. In implementations, however, in order to have optimal decoupling, it is preferred that the couplers also be implemented as switches or integrated in the input / output switch.

In addition, a first temperature sensor is used on the evaporator side as a special temperature sensor and a second temperature sensor is used on the condenser side as the second temperature sensor, with a more direct measurement is preferred. The evaporator-side measurement is used, in particular, to carry out a speed control of the temperature regulator, for example a compressor of the first and / or second stage, while the condenser-side measurement or else an ambient temperature measurement is used to carry out a mode control, that is to say around the heat pump For example, to switch from the bypass mode to the free cooling mode when a temperature is no longer in the very cold temperature range, but in the medium-cold temperature range. However, if the temperature is higher, ie in a warm temperature range, then the switching device Put the heat pump in a normal mode with first active level or with two active levels.

In a two-stage heat pump, however, in this normal mode, which corresponds to the mid-power mode, only a first stage will be active, while the second stage is still inactive, ie, not powered, and therefore does not require energy. Only when the temperature continues to increase, namely in a very warm area, in addition to the first heat pump stage or in addition to the first pressure stage, a second pressure stage is activated, which in turn has an evaporator, a Temperaturanhe- ber typically in the form of a radial compressor and a condenser , The second pressure stage can be connected in series or in parallel or serially / parallel to the first pressure stage.

To ensure that in the bypass mode, ie when the outside temperatures are already relatively cold, the cold from the outside does not completely penetrate the heat pump system and beyond in the room to be cooled, making the room to be cooled even colder than it should be, For example, it is preferable to provide a control signal from a sensor signal on the trace to the area to be cooled or at the return of the area to be cooled, which may be used by a heat dissipation device installed outside the heat pump to control the heat release, ie the temperatures get too cold, reduce. The heat dissipation device is, for example, a liquid / air heat exchanger, with a pump for circulating the liquid brought into the area to be heated. Further, the heat dissipation device may include a fan to transport air into the air heat exchanger. Additionally or alternatively, a three-way mixer may be provided to partially or completely short the air heat exchanger. Depending on the trace in the area to be cooled, which is connected in this bridging mode but not with the evaporator outlet, but with the return from the area to be heated, the heat dissipation device, so for example, the pump, the fan or the three-way Controlled in order to further reduce the heat output, so that a temperature level is maintained, in the heat pump system and in the area to be cooled, which in this case may be above the outdoor temperature level. Thus, the waste heat can even be used for heating the "room to be cooled" if the outside temperatures are too cold. In a further aspect, an overall control of the heat pump is carried out such that depending on a temperature sensor output signal of a temperature sensor on the evaporator side a .Feinsteuerung "of the heat pump is made, so a speed control in the various modes, eg the free cooling mode, the normal mode with first In the bypass mode, while the mode conversion is made from a temperature sensor output of a condenser-side temperature sensor as coarse control, a mode switching from the bypass mode (or NLM) to the condenser-side temperature sensor is performed the free cooling mode (or FKM) and / or in the normal mode (MLM or HLM), wherein the evaporator side temperature output signal is not taken to decide whether a switch takes place. However, only the evaporator-side temperature output signal is used for the speed control of the radial compressor or for the control of the heat dissipation devices, but not the condenser-side sensor output signal.

It should be noted that the various aspects of the present invention regarding the arrangement and the two-stage, as well as the use of the bypass mode, the control of the heat dissipation device in the lock-up mode or free cooling mode and the control of the centrifugal compressor in the free cooling mode or the normal operating mode or with respect to Using two sensors, one sensor for operating mode switching and the other fine-tuning sensor used, can be used independently. However, these aspects can also be combined in pairs, or in larger groups or together.

FIGS. 7A to 7D show an overview of various modes in which the heat pump according to FIGS. 1, 2, 8A, 9A can be operated. If the temperature of the area to be heated is very cold, such as less than 16 "C, the operating mode selection will activate the first operating mode in which the heat pump is bypassed and the control signal 36b for the heat dissipation device is generated in the area 16 to be heated Temperature of the area to be heated, ie the area 16 of FIG. 1 in a medium cold temperature range, eg in a range between 16 ° C and 22 ° C, the operating mode control will activate the free cooling mode, in which due to the low temperature spread the first stage the heat pump low power can work. However, if the temperature of the area to be heated is in a warm temperature range, for example between 22 ° C and 28 ° C, then the heat pump is operated in the normal mode but in the normal mode with a first heat pump stage. However, if the outside temperature is very warm, ie in a temperature range between 28 ° C and 40 ° C, a second heat pump stage is activated, which also works in normal mode and already supports the first stage continuously.

Preferably, a speed control or "fine control" of a centrifugal compressor within the Temperaturanhebers 34 of FIG. 1 in the temperature ranges "medium cold", "warm", "very warm" made to operate the heat pump always only with the heat / cooling capacity, the is required by the actual requirements. Preferably, the mode switching is controlled by a condenser-side temperature sensor, while the fine control or the control signal for the first operating mode depends on an evaporator-side temperature.

It should be noted that the temperature ranges are "very cold", "medium cold", "warm", "very warm" for different temperature ranges, the average temperature of which is very cold to medium cold, too hot, too hot respectively larger becomes. As shown with reference to FIG. 7C, the regions may be directly adjacent to each other. However, in embodiments, the regions may also overlap and be at the stated temperature level or at any other higher or lower temperature level. Furthermore, the heat pump is preferably operated with water as a working medium. However, other means may be used depending on the requirement.

This is tabulated in FIG. 7D. If the condenser temperature is in a very cold temperature range, the first mode of operation is set in response to the controller 430. If it is found in this mode that the evaporator temperature is lower than a setpoint temperature, a reduction in the heat output is achieved by a control signal at the heat dissipation device. However, if the condenser temperature is in the mid-cold range, then in response, it is expected to switch to the free cooling mode from controller 430, as represented by lines 431 and 434. If the evaporator temperature is greater than a setpoint temperature, this results in Response to an increase in the speed of the compressor radial compressor via the control line 434. In turn, if it is determined that the condenser temperature is in a warm temperature range, then the first stage is put into normal operation, which is signaled on line 434 , If, in turn, it is determined that at a certain speed of the compressor, the evaporator temperature is still greater than a desired temperature, then this leads to an increase in the speed of the first stage again via the control signal on line 434. Finally, it is determined that the Condenser is in a very warm temperature range, so in response to this, a second stage in normal operation is switched on, which in turn is done by a signal on line 434. Depending on whether the evaporator temperature is greater or less than a desired temperature, as signaled by signals on the line 432, then a control of the first and / or the second stage is made to respond to a changed situation. Thus, a transparent and efficient control is achieved, on the one hand, a "coarse tuning" due to the mode switching and on the other a "fine-tuning" due to the temperature-dependent speed adjustment, to the effect that always only as much energy must be consumed, as is actually needed , This procedure, in which there is also no permanent on-off in a heat pump, such as in known heat pumps with hysteresis also ensures that due to the continuous operation no start-up losses.

Preferably, a speed control or "fine control" of a centrifugal compressor within the compressor motor of Fig. 1 in the temperature ranges "medium cold", "warm", "very warm" made to operate the heat pump always only with the heat / cooling capacity, of the actual requirements is being demanded. Preferably, the mode switching is controlled by a receiver-side temperature sensor, while the fine control or the control signal for the first mode of operation depends on an evaporator-side temperature.

In mode switching, the controller 430 is configured to detect a condition for transition from the mid-power mode to the high-power module. Then, the compressor 304 is started in the further heat pump stage 300. First after staking a predetermined time greater than one minute, and preferably even greater than four or even five minutes, the controllable path module will switch from the assist power mode to the high power mode. This ensures that it is easy to switch from standstill, with the running of the compressor motor before switching over ensuring that the pressure in the evaporator is lower than the pressure in the compressor.

It should be noted that the temperature ranges in FIG. 7C can be varied. In particular, the threshold temperatures, between a very cold temperature and a medium-low temperature, ie the value 16 ° C. in FIG. 7C and between the medium-cold temperature and the warm temperature, ie the value 22 ° C. in FIG. 7C and the value between the warm and the very warm temperature, ie the value 28 ° C. in FIG. 7C by way of example only. Preferably, the threshold temperature between warm and very warm, in which a switch from the mid-power mode to the high-power mode takes place, is between 25 and 30 ° C. Further, the threshold temperature between warm and medium cold, that is, when switching between the free cooling mode and the medium power mode, in a temperature range between 18 and 24 ° C. Finally, the threshold temperature at which to switch between the medium cold mode and the very cold mode is in a range between 12 and 20 ° C, with the values preferably being as shown in the table in Fig. 7C However, as I said, can be set differently in the above areas.

Depending on the implementation and requirement profile, however, the heat pump system can also operate in four operating modes, which are also different, but all are at a different absolute level, so that the terms "very cold", "medium cold", "warm", "very warm "are to be understood only relative to each other, but are not intended to represent absolute temperature values. Although certain elements are described as device elements, it should be understood that this description is likewise to be regarded as a description of steps of a method and vice versa. Thus, for example, the block diagrams described in FIGS. 6A to 6D likewise represent flowcharts of a corresponding method according to the invention. It should also be appreciated that the control may be implemented as software or hardware, for example, by element 430 in FIG. 4B, as well as for the tables in FIGS. 4C, 4D, or 7A, 7B, 7C, 7D. The implementation of the controller may be on a non-volatile storage medium, a digital or other storage medium, in particular a floppy disk or CD with electronically readable control signals, which may interact with a programmable computer system such that the corresponding method of pumping heat or operating a heat pump is running. In general, the invention thus also encompasses a computer program product with a program code stored on a machine-readable carrier for carrying out the method when the computer program product runs on a computer. In other words, the invention can thus also be realized as a computer program with a program code for carrying out the method when the computer program runs on a computer.

Claims

claims

1 . Heat pump system with the following Merkmaien: a first heat pump assembly (1 1 1) having a compressor (1 12) with a compressor output (1 13); a second heat pump assembly (11-14) having an input portion (14a) and an output portion (14b); and a coupler (1 15) for thermally coupling the first heat pump assembly (1 1 1) and the second heat pump assembly (1 14), wherein the coupler (1 15) has a first heat exchanger (1 15a) and a second heat exchanger (1 15b) wherein the first heat exchanger (1 15a) is connected to the inlet section (1 14a) of the second heat pump arrangement (1 4), and wherein the second heat exchanger (1 15b) is connected to the outlet section (1 14b) of the second heat pump arrangement (1 14) is, wherein a working fluid in the first heat pump assembly (101, 1 1 1) C02 or a working fluid in the second heat pump assembly (102, 1 14) has water.

2. Heat pump system according to claim 1, wherein the first heat pump assembly (1 1 1) is designed to work with a first working fluid, wherein the second heat pump assembly (1 14) is designed to work with a second working fluid, wherein the second working medium from the first working medium with regard to the materia! or in which the first heat pump assembly (1 1 1) is adapted to operate at a first working pressure, wherein the second heat pump assembly (1 14) is adapted to operate at a second pressure, wherein the second pressure of the first pressure, and wherein the first pressure is higher than the second pressure.

3. Heat pump system according to claim 1 or 2, further comprising a recooler (131) adapted to be coupled to an environment, wherein the output portion (1 14b) of the second heat pump assembly (1 14, 102) is coupled to the recooler (131). 4. Heat pump system according to claim 3, wherein the output section (1 14b) comprises a heat exchanger (130) through which a Rückkühlerkreisiauf of the second heat pump assembly (102, 1 14) is fluidically separated, wherein the recooler circuit is adapted to at a pressure to work, which is higher than a pressure in the second heat pump assembly, and which is smaller than a pressure in the first heat pump assembly (101, 1 1 1).

A heat pump system according to claim 4, wherein the recooling circuit is configured to use a liquid different from a working fluid of the first heat pump assembly (101, 11) and a working fluid of the second heat pump assembly (11 1, 11).

Heat pump system according to one of claims 1 to 5, wherein the coupler (103, 1 15) has a first heat exchanger (1 15a) having a primary side and a secondary side, wherein the secondary side with an evaporator (120, 202, 320) of the second heat pump assembly can be coupled, and wherein the primary side of the first heat exchanger (1 15a) with the first heat pump assembly (1 1 1) is coupled.

Heat pump system according to one of the preceding claims, wherein the coupler (103, 1 5) has a second heat exchanger (1 15b) having a primary side and a secondary side, wherein the secondary side with a condenser (122, 206, 306) of the second heat pump assembly (102, 1 14) is coupled, and wherein the primary side of the second heat exchanger with the first heat pump assembly (101, 1 1 1) is coupled. Heat pump system according to one of the preceding claims, wherein the first heat pump assembly (101, 1 1 1) comprises a compressor (1 12), wherein the Koppier (103, 1 15) a first heat exchanger (115 a) and a second heat exchanger (1 15 b) wherein the second heat exchanger (1 15b) with the compressor (1 12) of the first heat pump assembly (101, 1 1 1) is coupled, and wherein the first heat exchanger (1 15a) with the second heat exchanger (1 15b) via a Verbindungsieitung (1 15c) is coupled ..

Heat pump system according to one of the preceding claims, wherein the first heat exchanger (1 15a) has a primary side with a first primary inlet (1 15c) and a first primary outlet (132), wherein the first heat exchanger (1 15a) has a secondary side with a first secondary input (120b) and a first secondary outlet (120a), wherein the second heat exchanger (1 15b) has a primary side with a second primary inlet (1 13) and a second primary outlet (1 15c), wherein the second heat exchanger (1 15b) a secondary side having a second secondary output (131 a) and a second secondary input (134), wherein the second primary input (1 13) is connected to a compressor output of the first heat pump assembly, the second primary output via a connecting line (1 15c) with a first primary input of the first heat exchanger (1 15a) is connected, and wherein the first primary output (132) of the first heat cher (1 15a) with a location of the first heat pump system (100, 1 1 1) is thermally coupled, which differs from the compressor output.

Heat pump system according to claim 9, wherein the location of the first heat pump system, to which the first primary outlet (132) of the first heat exchanger (1 15a) is coupled, an evaporator input of an evaporator (1 16) of the first heat pump assembly or a throttle input of a throttle (1 17) of the first heat pump assembly (100, 1 1 1).

Heat pump system according to claim 9 or 10, wherein the first secondary input (120b) or the first secondary output (120a) with an input portion (230, 401) or an evaporator (120, 102) of the second heat pump assembly (1 14) is connected.

Heat pump system according to one of claims 9 to 1 1, wherein the second secondary input (134) with an output portion (1 14b, 402, 340, 214) of the second heat pump assembly or with a condenser (122) of the second heat pump assembly is connected, or wherein the second secondary outlet (131 a) is connected to a recooler (131).

Heat pump system according to one of claims 9 to 12, comprising a recooler (131), wherein the output portion (1 14b, 402, 340, 214) of the second heat pump assembly has an output heat exchanger (130, 214), whose primary side with the recooler (131) can be coupled, and whose secondary side with a condenser (306), or an output portion (402, 340) of the second heat pump assembly is coupled.

Heat pump system according to one of the preceding claims, wherein the first heat exchanger (1 15a) and the second heat exchanger (1 15b) are designed for pressures above 15 bar.

Heat pump system according to one of claims 1 to 14, wherein the second heat pump assembly has an input portion (1 14a) and an output portion (1 14b) and is adapted to depending on a temperature (124a, 124b) at the input portion (1 14a) or a temperature (124c, 124d) at the output portion (1 14b) such that absorption of electric power by the second heat pump assembly (102, 14 ) increases at an increasing temperature (124a, 124b, 124c, 124d) at the input portion (11a) or the output portion (14b) and decreases as the temperature (124a-124d) at the input portion (11a, 14b) decreases.

Heat pump system according to claim 15, wherein a relationship between a recording of the electric power and the temperature (100a-124d) at the input portion (1 14a) or the output portion (1 14b) at least in an operating mode of the second heat pump assembly (102, 1 14) is approximately linear.

Heat pump system according to claim 15 or 16, wherein the second heat pump assembly comprises a turbocompressor (121) with a radial wheel, wherein a rotational speed of the radial wheel depending on the temperature (124a-124d) at the input portion (1 14a) or the output portion (1 14b) is controllable.

A heat pump system according to any one of the preceding claims, wherein the working fluid in the first heat pump assembly (101, 11) has CO 2 and the working fluid in the second heat pump assembly (102, 14) comprises water.

A heat pump system according to any one of the preceding claims, wherein the second heat pump assembly (102, 14) comprises: a heat pump stage (200) having a first evaporator (202), a first condenser (206) and a first compressor (204); and another heat pump stage (300) having a second evaporator (302), a second condenser (306) and a second compressor (304), wherein a first condenser exit (224) of the first condenser (206) is connected to a second evaporator inlet (322) of the second evaporator (302) via a connection line (332).

The heat pump system of claim 19, wherein the second heat pump assembly further includes a controllable path module to drive the heat pump assembly and the controllable path module (420) to operate the second heat pump assembly in one of at least two different modes, the second heat pump assembly being configured to performing at least two modes selected from a group of modes having the following modes: a high power mode in which the heat pump stage (100) and the further heat pump stage (200) are active; a mitteilistungsmodus in which the heat pump stage (200) is active and the further heat pump stage (300) is inactive; a free cooling mode in which the heat pump stage (200) is active and the further heat pump stage (300) is inactive and the second heat exchanger (214) is coupled to an evaporator inlet (222) of the heat pump stage (200); and a low power mode in which the heat pump stage (200) and the further heat pump stage (300) are inactive, wherein the controller is configured to detect a condition for transition from the mid power mode to the high power module to power the compressor (304) in the to start another heat pump stage (300), and only to switch the controllable path module from the middle power mode to the high power mode after elapse of a predetermined time greater than one minute. 21. Heat pump system according to claim 19 or 20, wherein the second heat pump assembly (102, 1 14) has the following features: a first heat exchanger (212) on a side to be cooled; a second heat exchanger (214) on a side to be heated; a first pump (208) coupled to the first heat exchanger (212), a second pump (210) coupled to the second heat exchanger (214); and a first temperature sensor (602) on a return (241) from the first heat exchanger (212); a second temperature sensor (604) at a return (243) from the second heat exchanger (214); a controller to operate the second heat pump assembly in one of at least two different modes, the second heat pump assembly configured to perform at least two modes selected from a group of modes having the following modes: a high power mode in which the Heat pump stage (100) and the other heat pump stage (200) are active; a mid-power mode in which the heat pump stage (200) is active and the further heat pump stage (300) is inactive; a free cooling mode in which the heat pump stage (200) is active and the further heat pump stage (300) is inactive and the second heat exchanger (214) is coupled to an evaporator inlet (222) of the heat pump stage (200); and a low power mode in which the heat pump stage (200) and the further heat pump stage (300) are inactive. wherein the controller is configured to switch from an operating mode to the free-cooling mode depending on a difference between a first temperature detected by the first temperature sensor (602) and a second temperature determined by the second temperature sensor ( 604) is detected.

The heat pump system of any one of claims 19 to 21, wherein the second heat pump assembly (102, 14) includes: a controllable path module (420) and further a controller (430) to control the heat pump unit and the controllable path module (420), to operate the second heat pump assembly in one of at least two different modes, wherein the second heat pump assembly is configured to perform at least two modes selected from a group of modes having the following modes: a high power mode in which the heat pump stage (100 ) and the further heat pump stage (200) are active; a mid-power mode in which the heat pump stage (200) is active and the further heat pump stage (300) is inactive; a free cooling mode in which the heat pump stage (200) is active and the further heat pump stage (300) is inactive and the second heat exchanger (214) is coupled to an evaporator inlet (222) of the heat pump stage (200); and a low power mode in which the heat pump stage (200) and the further heat pump stage (300) are inactive, wherein the controller is configured to operate the second heat pump assembly in the high power mode when a temperature of a region to be heated is greater than a very warm temperature is to operate the second heat pump assembly in the mid-power mode when a temperature of a region to be heated is greater than a warm temperature that is less than the very warm temperature to operate the second heat pump assembly in the free cooling mode when a temperature of a region to be heated is greater than a medium cold temperature, which is lower than the warm temperature, and to operate the low heat mode second heat pump assembly when a temperature of a region to be heated is lower than the medium cold temperature.

23. Heat pump system according to claim 22, wherein the very warm temperature is between 35 ° and 30 ° C, wherein the warm temperature is between 18 ° C and 24 ° C, or at the medium cold temperature between 12 ° C and 20 ° C is.

24. A method for producing a heat pump system comprising a first heat pump assembly (1 1 1) having a compressor (112) with a compressor outlet (1 13); and a second heat pump assembly (11-14) having an input portion (11a) and an output portion (14b), comprising the steps of: thermally coupling the first heat pump assembly (11) and the second heat pump assembly (114) Use of a first heat exchanger (1 15a) and a second heat exchanger (1 15b), by connecting the first heat exchanger (1 15a) with the input portion (1 14a) of the second heat pump assembly (1 14) and the second heat exchanger (1 15b) with the Output section (1 14b) of the second heat pump assembly (1 14), wherein a working fluid in the first heat pump assembly (101, 1 1 1) CO 2 or a working fluid in the second heat pump assembly (102, 1 14) comprises water.

25. Method for operating a heat pump system, comprising the following steps: Operating a first heat pump assembly (101, 1 1 1) having a compressor (1 12) with a compressor outlet (1 13);

Operating a second heat pump assembly (102, 14) having an input portion (11a) and an output portion (14b); and

Thermally coupling the first heat pump assembly (101, 11) and the second heat pump assembly (102, 11) using a first heat exchanger (15a) and a second heat exchanger (15b), the first heat exchanger (115a) communicating with the first heat exchanger Input portion (1 14a) of the second heat pump assembly (102, 1 14) is connected, and wherein the second heat exchanger (1 15b) to the output portion (1 14b) of the second heat pump assembly (102, 1 14) is connected, wherein a working fluid in the first heat pump assembly (101, 1 1 1) C02 or a working fluid in the second heat pump assembly (102, 1 14) comprises water.