Heat pump system with heat exchangers, method for operating a heat pump system and method for manufacturing a heat pump system

Abstract

Heat pump system with the following features: a heat pump unit with at least one heat pump stage (200), wherein the at least one heat pump stage (200) comprises an evaporator (202), a compressor (204) and a condenser (206); 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); and a second pump (210) which is coupled to the second heat exchanger (214), wherein the heat pump system has an operating position, wherein in the operating position the first pump (208) or the second pump (210) is arranged above the first heat exchanger (212) or the second heat exchanger (214), and the heat pump unit is located above the first pump (208) and the second pump (210).

Description

[0001] The present invention relates to heat pumps for heating, cooling or for any other application of a heat pump.

[0002] Fig. 8A and Fig. 8B represents a heat pump as described in European patent EP 2016349 B1. The heat pump initially comprises an evaporator 10 for evaporating water as the working fluid in order to generate steam in a working steam line 12 at the outlet. The evaporator comprises an evaporation chamber (in Fig. (8A not shown) and is designed to generate an evaporation pressure of less than 20 hPa in the evaporation chamber, so that the water evaporates at temperatures below 15 °C in the evaporation chamber. The water can be, for example, groundwater, brine circulating freely in the ground or in collector pipes (i.e., water with a specific salinity), river water, lake water, or seawater. All types of water can be used, including hard water, soft water, saline water, or salt-free water. This is because all types of water, i.e., all these "hydrogens," possess the favorable property of water, namely that water, also known as "R 718," has a usable enthalpy difference ratio of 6 for the heat pump process, which is more than twice that of the typical usable enthalpy difference ratio of, for example, R134a.

[0003] The steam is fed through the suction line 12 to a compressor / condenser system 14, which includes a turbo compressor such as a radial compressor, for example in the form of a turbo compressor, which is located in Fig. The turbomachine is designated 8A with 16. It is designed to compress the working steam to a vapor pressure at least greater than 25 hPa. 25 hPa corresponds to a condensing temperature of approximately 22 °C, which can be a sufficient flow temperature for underfloor heating, at least on relatively warm days. To generate higher flow temperatures, pressures greater than 30 hPa can be produced with turbomachine 16, where a pressure of 30 hPa corresponds to a condensing temperature of 24 °C, a pressure of 60 hPa to a condensing temperature of 36 °C, and a pressure of 100 hPa to a condensing temperature of 45 °C. Underfloor heating systems are designed to provide sufficient heating even on very cold days with a flow temperature of 45 °C.

[0004] The turbomachine is coupled to a condenser 18, which is designed to liquefy the compressed working steam. Through condensation, the energy contained in the working steam is transferred to the condenser 18 and then fed to a heating system via the supply line 20a. The working fluid flows back into the condenser via the return line 20b.

[0005] According to the invention, it is preferred to extract the heat (energy) directly from the energy-rich water vapor by means of the colder heating water, which is then absorbed by the heating water, thus warming it up. So much energy is extracted from the vapor that it liquefies and also participates in the heating circuit.

[0006] This results in the introduction of material into the condenser or the heating system, which is regulated by a drain 22, such that the condenser in its condensing chamber has a water level that, despite the constant supply of water vapor and thus condensate, always remains below a maximum level.

[0007] As already explained, an open circuit is preferred, meaning the water, which serves as the heat source, is evaporated directly without a heat exchanger. Alternatively, however, the water to be evaporated could first be heated via a heat exchanger from an external heat source. Furthermore, to avoid losses for the second heat exchanger, which is currently necessary on the condenser side, the medium can also be used directly there. If the house has underfloor heating, the water from the evaporator can be circulated directly in the underfloor heating system.

[0008] Alternatively, a heat exchanger can also be arranged on the condenser side, which is supplied with the flow 20a and has the return 20b, whereby this heat exchanger cools the water in the condenser and thus heats a separate underfloor heating fluid, which will typically be water.

[0009] Because water is used as the working medium, and because only the evaporated portion of the groundwater is fed into the turbomachine, the water's purity level is irrelevant. The turbomachine, as well as the condenser and any directly connected underfloor heating system, is always supplied with distilled water, resulting in reduced maintenance compared to current systems. In other words, the system is self-cleaning, as it is always supplied with distilled water, and therefore the water in outlet 22 remains uncontaminated.

[0010] Furthermore, it should be noted that turbomachinery has the characteristic that – similar to an aircraft turbine – it does not bring the compressed medium into contact with problematic substances such as oil. Instead, the water vapor is merely compressed by the turbine or turbo compressor, but is not brought into contact with oil or any other medium that could impair its purity and thus not contaminated.

[0011] The distilled water discharged through the drain can therefore – provided no other regulations prohibit it – be readily returned to the groundwater. Alternatively, it can also be allowed to seep into the ground in the garden or an open area, or, if required by regulations, it can be conveyed to a wastewater treatment plant via the sewer system.

[0012] The combination of water as a working fluid with a usable enthalpy difference ratio that is twice as good as that of R134a, and the resulting reduced requirements for the system's closedness, and the use of a turbomachine that efficiently achieves the necessary compression factors without compromising purity, creates an efficient and environmentally neutral heat pump process.

[0013] Fig. Figure 8B shows a table illustrating different pressures and the evaporation temperatures associated with these pressures, which shows that particularly for water as the working medium, quite low pressures should be chosen in the evaporator.

[0014] DE 4431887 A1 discloses a heat pump system with a lightweight, large-volume, high-performance centrifugal compressor. Steam exiting a second-stage compressor has a saturation temperature exceeding the ambient temperature or that of available cooling water, thus enabling heat dissipation. The compressed steam is transferred from the second-stage compressor to the condenser unit, which consists of a packed bed located within a cooling water spray device at the top, supplied by a water circulation pump. The compressed steam rises through the packed bed in the condenser, where it comes into direct countercurrent contact with the downward-flowing cooling water.The steam condenses, and the latent heat of condensation, absorbed by the cooling water, is released to the atmosphere via the condensate and the cooling water, which are removed from the system together. The condenser is continuously purged with non-condensable gases via a vacuum pump through a pipeline.

[0015] WO 2014072239 A1 discloses a condenser with a condensation zone for condensing vapor to be condensed in a working fluid. The condensation zone is designed as a volume zone and has a lateral boundary between its upper and lower ends. Furthermore, the condenser includes a vapor inlet zone extending along the lateral end of the condensation zone and designed to introduce vapor to be condensed laterally over the lateral boundary into the condensation zone. This transforms the actual condensation into volume condensation without increasing the volume of the condenser, because the vapor to be condensed is not only introduced frontally from one side into a condensation volume or zone, but laterally and preferably from all sides.This not only ensures that the available condensation volume is increased compared to direct countercurrent condensation with the same external dimensions, but also that the efficiency of the condenser is improved because the vapor to be liquefied has a flow direction perpendicular to the flow direction of the condensing liquid in the condensation zone.

[0016] With heat pump systems, especially when used for heating or cooling, but not exclusively in the small to medium output range, unreliable operation or bulkiness can be a disadvantage. Such problems can arise when the working fluid is kept at a relatively low pressure, as is the case with water. In such cases, it is particularly important to ensure that the pressure in the working fluid on the pump's suction side does not drop too low. If this were to occur, the pump's activity—namely, when the impeller transfers energy to the fluid—would cause bubbles to form. These bubbles then collapse. This process is called cavitation. If cavitation occurs at all, or if it does, it is crucial to ensure that the pump is properly cooled.If cavitation occurs with a certain intensity, it can eventually damage the pump impellers and thus reduce the service life of the heat pump system. Furthermore, a damaged but still functioning pump impeller leads to a decrease in pump efficiency. If this reduced efficiency is compensated for by increasing the pumping power, this results in unnecessary energy consumption and therefore reduced efficiency of the heat pump system. Conversely, if the pumping power is not compensated for, a pump already damaged by excessive cavitation but still functioning will deliver a smaller pumped volume, which also results in reduced efficiency of the heat pump system.

[0017] Another aspect of a heat pump system with heat exchangers is how the system can be commissioned. This includes filling the heat exchangers during initial commissioning or after a maintenance shutdown. Generally, one heat exchanger is provided on the cold water side and another on the hot or cooling water side. These heat exchangers, which are typically very heavy, should be efficiently coupled with pumps and heat pump stages. They should also be easy to maintain and, in particular, installed in such a way that commissioning or decommissioning the heat pump system is as simple, safe, and service-friendly as possible.

[0018] Another point that plays a significant role is the use of multiple heat pump stages in a heat pump system and the coupling of the heat pump stages with each other or with various pumps or heat exchangers to create an optimal heat pump system that works efficiently, has a good service life, or is flexible enough to be used for various operating conditions.

[0019] DE 10 2007 005 930 A1 discloses a heat pump with a first section for evaporating a working fluid at a first pressure, for compressing the evaporated working fluid to a second higher pressure and for liquefying the compressed working fluid in a condenser, and a second section for compressing liquid working fluid to a third pressure higher than the second pressure, for evaporating the working fluid compressed to the third pressure, for relaxing the evaporated working fluid to a pressure lower than the third pressure in order to generate electricity and for liquefying relaxed evaporated working fluid in the condenser.

[0020] DE 10 2012 208 175 A1 discloses a heat pump system comprising a first heat pump stage (10) with a first evaporator inlet (11a) and a first evaporator outlet (11b), a first condenser inlet (13a) and a first condenser outlet (13b), and a second heat pump stage (12) with a second evaporator inlet (15a) and a second evaporator outlet (15b), a second condenser inlet (17a) and a second condenser outlet (17b), wherein the first evaporator outlet (11b) is fluidically coupled to the second evaporator inlet (15a), and wherein the second condenser outlet (17b) is fluidically coupled to the first condenser inlet (13a).

[0021] The object of the present invention is to provide an improved heat pump system, a method for manufacturing a heat pump system, and a method for operating a heat pump system.

[0022] This problem is solved by a heat pump system according to claim 1, a method for manufacturing a heat pump system according to claim 31 or a method for operating a heat pump system according to claim 32.

[0023] In one aspect of the present invention, the heat exchangers are arranged at the bottom of the heat pump system, specifically below the pumps. Such a heat pump system comprises a heat pump unit with at least one, and preferably several, heat pump stages. Furthermore, a first heat exchanger is provided on a side to be cooled. In addition, a second heat exchanger is provided on a side to be heated. Furthermore, there is a first pump coupled to the first heat exchanger and a second pump coupled to the second heat exchanger. The heat pump system has an operating position in which the first pump and the second pump are arranged above the first and second heat exchangers, respectively. Furthermore, the heat pump unit with the one or more heat pump stages is arranged above the first and second pumps.

[0024] An advantage of this arrangement, according to one aspect of the invention, is the low center of gravity. The heat exchangers are typically the heaviest components. In this embodiment, the pump module is arranged above the heat exchangers, and optionally, when using multiple heat pump stages, a mixing module is also arranged above the pump module. The one or more tanks containing the compressor(s) of the heat pump stages are located at the highest point. A particular advantage of arranging the compressors at the highest point is that they are dry when off. In this state, the working fluid, such as water, drains downwards due to gravity.

[0025] This arrangement with bottom-mounted heat exchangers is characterized by its lightweight construction. First, the heat exchangers are mounted, for example, in a heat pump frame. Then, the pump module, optionally the mixing or distribution module, and finally one or more heat pump stages are added. Preferably, the heat exchangers are arranged horizontally. This ensures that no air pockets form when the heat pump system is filled during initial commissioning or after a maintenance interval, meaning the heat pump system is self-venting.

[0026] Furthermore, in this embodiment, it is preferred that all pumps are arranged in downpipes, i.e., not in riser pipes. In particular, the pumps are arranged so that the suction side of the pump is located as low as possible in the downpipe. This allows kinetic energy to be extracted from the falling height of the water column, and the pressure on the suction side of the pump is higher than in a riser pipe running from bottom to top. This results in a lower minimum water column on the suction side of the pump than required by the pump manufacturer. This prevents cavitation altogether or excessive cavitation. It also achieves a compact heat pump system that does not require a particularly large amount of space for installation. This is because the pipe connections before the suction side of the pump can be kept short. This makes the entire system more compact and therefore less bulky.Weight savings can also be achieved through a more compact design.

[0027] In a second aspect of the present invention, the heat pump system is equipped with pumps located at the very bottom. Therefore, as an alternative to the first aspect described, according to the second aspect of the present invention, in the operating position, the first and second pumps are arranged below the heat pump unit at a lower end of the heat pump system. Furthermore, in this arrangement, the first and second heat exchangers are also located below the heat pump unit at the lower end, next to the pumps. Thus, to effectively prevent cavitation, the pumps are positioned at the lowest point of the heat pump system. In addition, the pumps are installed horizontally so that the maximum back pressure exists in front of the pump's suction side. This effectively prevents cavitation and thus damage to the pump impellers.The required back pressure upstream of the pump's suction side determines the smallest possible height difference between the heat pump stage—that is, the tank containing the condenser, evaporator, and compressor—and the corresponding pump. Preferably, the heat exchanger is mounted vertically to prevent air pockets during filling. Furthermore, the vertical orientation of the heat exchanger shortens the necessary pipe connection from the heat exchanger back to the evaporator or condenser, because the heat exchanger itself, which can typically be quite long, is essentially used twice as a connecting pipe.

[0028] In a third aspect of the present invention, the heat pump system is not operated with just a single heat pump stage, but with two or more heat pump stages. Here, the heat pump stage with a first compressor, a first condenser, and a first evaporator is connected, as it were, in series with a second or further heat pump stage with a second compressor, a second condenser, and a second evaporator. For this purpose, the first condenser outlet of the first condenser is connected to the second evaporator inlet of the second evaporator of the further heat pump stage via a connecting line. This introduces the warmest fluid of the heat pump stage into the evaporator, i.e., the coldest area of ​​the further heat pump stage, to be cooled there. The heat pump stages are therefore not connected in parallel, but in series.Depending on the implementation, the inlet of the condenser of the first heat pump stage can be coupled with the outlet of the evaporator of the next heat pump stage, or, as is preferred in certain embodiments, it can be routed into a controllable path module in order to operate the heat pump system with the heat pump stage and the next heat pump stage in various operating modes optimally adapted to the heating or cooling task.

[0029] In preferred embodiments of the third aspect of the present invention, which relates to the cascade connection of two heat pump stages, the first condenser of the heat pump stage is arranged in the operating position above the second evaporator of the subsequent heat pump stage, so that the working fluid flows from the first condenser to the second evaporator in the connecting line due to gravity. This eliminates the need for a pump. An intermediate circuit pump is only required to raise the working fluid from the evaporator of the subsequent heat pump stage back to a higher level relative to the operating position in the condenser of the heat pump stage, i.e., the first heat pump stage.This means that a heat pump system with two heat pump stages can be operated efficiently with only three pumps: a first pump that is coupled to the inlet of the cold-side heat exchanger, a second pump that is coupled to the inlet of the hot-side heat exchanger, and an intermediate circuit pump that is coupled to the outlet of the evaporator of the further heat pump stage.

[0030] Further heat pump stages can also be arranged in a cascade configuration. If the condensers of the lower heat pump stage are located above the evaporators of the higher heat pump stage, pumps can be saved. Alternatively or additionally, the third stage, or further stages, can be coupled in parallel, in series, or in some other way to the two heat pumps connected in cascade.

[0031] The space below the higher-level heat pump stage is preferably used to house a controllable directional control module for implementing various operating modes. These modes include a high-performance mode, a medium-performance mode, a free-cooling mode, and a low-performance mode. According to the third aspect of the present invention, a control system is provided to adjust the controllable directional control module so that at least two of these four operating modes are implemented. In other embodiments, three operating modes are implemented, and in still other embodiments, all four operating modes are implemented. By using a larger number of heat pump stages, additional operating modes—more than four—can be implemented.

[0032] Due to the arrangement of the pumps and heat exchangers according to the first or second aspect, almost only straight point-to-point connections are achieved, which are advantageous for a compact design and cavitation avoidance.

[0033] As previously explained, the height difference between the two tanks eliminates the need for a pump between the condenser outlet of the higher tank and the evaporator inlet of the lower tank. The space gained by this height difference is used for the controllable diverter valve, which allows the heat pump system to be switched between different modes to achieve optimal adaptation to various operating conditions.

[0034] The arrangement of the two heat pump stages and their cascade connection—that is, by connecting the condenser outlet of the first stage to the evaporator inlet of the second stage—allows the existing infrastructure to be used in every operating mode. Both heat pump stages are therefore supplied with the working fluid regardless of whether they are active, i.e., whether the respective compressor is running or not. Thus, no bypass lines or valves are required. Instead, to switch between operating modes, the paths are reversed using a 2x2-way switch array.

[0035] This allows an inactive heat pump stage—that is, a heat pump stage where the compressor is not active and the pressure is the same on both the evaporator and condenser sides—to be brought into operation simply by starting the compressor, without any further measures. The system is thus designed so that no special start-up or evacuation procedures are necessary; instead, a heat pump stage starts when the compressor is activated and stops when the compressor is deactivated. Nevertheless, the inlets for the evaporator and condenser, as well as the outlets from the evaporator and condenser of a stage, continue to flow even when the compressor is deactivated. This ensures that optimal readiness is achieved without any additional energy consumption.

[0036] In another embodiment, an efficient working fluid transport system is used. It has been observed that working fluid accumulates in the evaporator of the lower stage, i.e., the stage thermodynamically located on the side to be heated. To allow for equalization with the evaporator in the higher-level vessel, a self-regulating system is employed, which may, for example, include an overflow and a U-tube. The U-tube is connected to a constriction upstream of a pump in the evaporator circuit of the higher-level vessel. Due to the increased flow velocity upstream of the pump, the pressure drops, and water from the U-tube can be drawn in. The system is self-regulating in this respect because a stable water level is established in the U-tube, which is sufficient to compensate for the pressure upstream of the pump at the constriction and in the evaporator of the lower-level vessel.

[0037] Preferred embodiments of the present invention are explained in detail below with reference to the accompanying drawings. These show: Fig. 1. A schematic representation of a heat pump stage with an interlocking evaporator / condenser arrangement; Fig. 2A a schematic representation of a heat pump system with bottom-mounted heat exchangers according to the first aspect of the present invention; Fig. 2B a schematic representation of a heat pump system with bottom-mounted pumps according to the second aspect of the present invention; Fig. 3A a schematic representation of a heat pump system with a first and further heat pump stage connected in series according to the third aspect of the present invention; Fig. 3B a schematic representation of two heat pump stages permanently connected in series; Fig. 4A a schematic representation of heat pump stages coupled in series with controllable directional switches. Fig. 4B a schematic representation of a controllable path module with three inputs and three outputs; Fig. 4C a table to show the different connections of the controllable path module for different operating modes; Fig. 5 a schematic representation of the heat pump system of Fig. 4A with additional self-regulating liquid balancing between the heat pump stages; Fig. 6A a schematic representation of the two-stage heat pump system operating in high-performance mode (HPM); Fig. 6B a schematic representation of the two-stage heat pump system operating in medium power mode (MKM); Fig. 6C a schematic representation of the two-stage heat pump system operated in free cooling mode (FKM); Fig. 6D a schematic representation of the two-stage heat pump system operating in low-power mode (NLM); Fig. 7A a table to show the operating states of various components in the different operating modes; Fig. 7B a table to show the operating states of the two coupled controllable 2x2-way switches; Fig. 7C a table showing the temperature ranges for which the operating modes are suitable; Fig. 7D a schematic representation of the coarse / fine control via the operating modes on the one hand and the speed control on the other; Fig. 8A a schematic representation of a known heat pump system using water as the working fluid; and Fig. 8B a table to illustrate different pressure / temperature situations for water as a working fluid.

[0038] Fig. Figure 1 shows a heat pump 100 with an evaporator for evaporating working fluid in an evaporator chamber 102. The heat pump further comprises a condenser for condensing the evaporated working fluid in a condenser chamber 104, which is bounded by a condenser base 106. As shown in Fig. As shown in Figure 1, which can be viewed as a sectional or side view, the evaporator chamber 102 is at least partially surrounded by the condenser chamber 104. Furthermore, the evaporator chamber 102 is separated from the condenser chamber 104 by the condenser base 106. In addition, the condenser base is connected to an evaporator base 108 to define the evaporator chamber 102. In one implementation, a compressor 110 is provided above the evaporator chamber 102 or elsewhere, which is located in Fig. 1 is not described in detail, but is designed in principle to compress evaporated working fluid and direct it as compressed vapor 112 into the condenser chamber 104. The condenser chamber is further bounded externally by a condenser wall 114. The condenser wall 114, like the condenser base 106, is attached to the evaporator base 108. In particular, the dimensions of the condenser base 106 in the area that forms the interface with the evaporator base 108 are such that the condenser base, when exposed to the heat generated by the evaporator, is designed to withstand the heat generated by the evaporator. Fig. In the embodiment shown in Figure 1, the capacitor compartment is completely surrounded by the capacitor space wall 114. This means that the capacitor compartment, as shown in Figure 1, is completely surrounded by the capacitor space wall 114. Fig. 1 shows that it extends to the evaporator base, and that the evaporator space extends very far upwards at the same time, typically through almost the entire condenser space 104.

[0039] This "interlocked" or interlocking arrangement of condenser and evaporator, characterized by the connection between the condenser base and the evaporator base, delivers particularly high heat pump efficiency and therefore allows for a very compact heat pump design. In terms of dimensions, the heat pump, for example in a cylindrical form, is dimensioned such that the condenser wall 114 forms a cylinder with a diameter between 30 and 90 cm and a height between 40 and 100 cm. However, the dimensions can be selected depending on the required performance class of the heat pump, but preferably within the dimensions mentioned.This results in a very compact design that is also easy and inexpensive to manufacture, because the number of interfaces, especially for the almost vacuum-operated evaporator chamber, can be easily reduced if the evaporator base is designed according to preferred embodiments of the present invention in such a way that it includes all liquid inlets and outlets, thus eliminating the need for liquid inlets and outlets from the side or from above.

[0040] Furthermore, it should be noted that the operating direction of the heat pump is as shown in Fig. Figure 1 shows that the evaporator base defines the lower section of the heat pump during operation, except for connecting lines to other heat pumps or corresponding pump units. This means that during operation, the vapor generated in the evaporator chamber rises and is redirected by the motor and fed from top to bottom into the condenser chamber. The condenser fluid is guided from bottom to top, then fed into the condenser chamber from above, and then flows from top to bottom within the condenser chamber, for example, as individual droplets or small liquid streams, to react with the preferably transversely supplied compressed vapor for condensation purposes.

[0041] This interlocking arrangement, in which the evaporator is located almost entirely or even completely within the condenser, enables a highly efficient heat pump design with optimal space utilization. Since the condenser chamber extends to the bottom of the evaporator, it occupies the entire height of the heat pump, or at least a significant portion of it. Simultaneously, the evaporator chamber is also as large as possible, as it too extends almost the entire height of the heat pump. This interlocking arrangement, in contrast to a design where the evaporator is located below the condenser, ensures optimal use of space.This allows for particularly efficient operation of the heat pump and a particularly space-saving and compact design, because both the evaporator and the condenser extend over the entire height. While this reduces the thickness of the evaporator and condenser chambers, it has been found that the reduction in the thickness of the evaporator chamber, which tapers within the condenser, is not problematic because the main evaporation takes place in the lower section, where the evaporator chamber fills almost the entire available volume. Conversely, the reduction in the thickness of the condenser chamber, especially in the lower section where the evaporator chamber fills almost the entire available space, is not critical because the main condensation occurs at the top, where the evaporator chamber is already relatively thin, thus leaving sufficient space for the condenser chamber.The interlocking arrangement is thus optimal in that each functional space is given the largest volume precisely where it requires it. The evaporator space has the largest volume at the bottom, while the condenser space has the largest volume at the top. Nevertheless, the corresponding smaller volume remaining for each functional space where the other has the largest volume also contributes to increased efficiency compared to a heat pump where the two functional elements are arranged one above the other, as is the case, for example, in WO 2014072239 A1.

[0042] In preferred embodiments, the compressor is arranged at the top of the condenser chamber such that the compressed vapor is both redirected by the compressor and simultaneously fed into a marginal gap of the condenser chamber. This achieves condensation with particularly high efficiency because a cross-flow direction of the vapor towards a downward-flowing condensate liquid is created. This cross-flow condensation is especially effective in the upper region, where the evaporator chamber is large, and in the lower region, where the condenser chamber is smaller to allow for the condensation of vapor particles that have penetrated to this area, a particularly large space is no longer required.

[0043] An evaporator base connected to the condenser base is preferably designed to accommodate both the condenser inlet and outlet and the evaporator inlet and outlet, and may also include specific feedthroughs for sensors into the evaporator and condenser, respectively. This eliminates the need for pipes for the condenser inlet and outlet through the evaporator, which is under near-vacuum. This makes the entire heat pump less prone to failure, as any penetration through the evaporator would represent a potential leak point. To achieve this, the condenser base is provided with a recess at each of the condenser inlet and outlet locations, ensuring that no condenser inlets or outlets run within the evaporator chamber defined by the condenser base.

[0044] The condenser chamber is bounded by a condenser wall, which can also be attached to the evaporator base. The evaporator base thus has an interface for both the condenser wall and the condenser base, and additionally houses all liquid inlets for both the evaporator and the condenser.

[0045] In certain designs, the evaporator base is shaped to include connection ports for the individual inlets, each with a cross-section that differs from the cross-section of the opening on the opposite side of the evaporator base. The shape of each connection port is designed such that its form, or cross-sectional shape, changes along its length, while the pipe diameter, which influences the flow velocity, remains nearly constant within a tolerance of ± 10%. This prevents cavitation of the water flowing through the connection port. The resulting improved flow characteristics, achieved through the design of the connection ports, allow for the shortest possible pipes / lines, contributing to a compact overall heat pump design.

[0046] With a specific evaporator base design, the condenser inlet is divided into two or more sections, almost like a "glasses." This allows the condenser fluid to be fed into the condenser at two or more points simultaneously at its upper section. This results in a strong yet exceptionally uniform condenser flow from top to bottom, enabling highly efficient condensation of the vapor also introduced into the condenser from above.

[0047] Another smaller inlet for condenser water can also be provided in the evaporator base to connect a hose that supplies coolant to the compressor motor of the heat pump, whereby the cooling is not done with the cold liquid supplied to the evaporator, but with the warmer liquid supplied to the condenser, which is still cool enough to cool the motor of the heat pump in typical operating conditions.

[0048] The evaporator base is characterized by its dual functionality. Firstly, it ensures that no condenser supply lines need to pass through the evaporator, which operates at very low pressure. Secondly, it provides an external interface, preferably circular, as this maximizes the available evaporator surface area. All inlet and outlet lines pass through the single evaporator base and from there into either the evaporator chamber or the condenser chamber. Manufacturing the evaporator base from injection-molded plastic is particularly advantageous because the relatively complex shapes of the inlet / outlet connections can be easily and cost-effectively produced using this process.On the other hand, due to the design of the evaporator base as an easily accessible workpiece, it is readily possible to manufacture the evaporator base with sufficient structural stability so that it can easily withstand the low evaporator pressure in particular.

[0049] In the present application, identical reference numerals refer to identical or equivalent elements, and not all reference numerals are repeated in all drawings.

[0050] Fig. Figure 2A shows a heat pump system with a heat pump unit comprising at least one heat pump stage 200, wherein the at least one heat pump stage 200 has an evaporator 202, a compressor 204, and a condenser 206. Furthermore, a first heat exchanger 212 is provided on a side to be cooled. In addition, a second heat exchanger 214 is provided on a side to be heated. The heat pump system also includes a first pump 208, which is coupled to the first heat exchanger 212, and a second pump 210, which is coupled to the second heat exchanger 214. The heat pump system has an operating position, i.e., a position in which it operates normally. This operating position is as shown in Figure 2A. Fig. Figure 2A shows the following. In the operating position, the first pump 208 and the second pump 210 are arranged above the first heat exchanger 212 and the second heat exchanger 214. Furthermore, the heat pump unit, which comprises at least one heat pump stage 200, is arranged above the first pump 208 and the second pump 210.

[0051] The first heat exchanger 212 comprises an inlet 240 and an outlet 241. The inlet 240 and the outlet 241 are coupled to the heat pump unit. In the implementation where the heat pump unit has only a single heat pump stage, as exemplified in Fig. As shown in Figure 2A at 200, the inlet 240 to the heat exchanger 212 is connected via pump 208 to an evaporator outlet 220 via a pipe 208 upstream of pump 208 and a pipe 230 downstream of pump 208. Furthermore, the outlet 241 from the heat exchanger 212 is connected to the evaporator inlet 222 of the evaporator 202 via a pipe 234. Additionally, a condenser outlet 224 of the condenser / condenser 206 is connected via pump 210 and a pipe 236 to an inlet 242 in the second heat exchanger 214. Finally, an outlet 243 of the second heat exchanger 214 is connected via a pipe to a condenser / condenser inlet 226 of the condenser 206. However, it should be noted that pipes 228, 232, 234, 238 can also be coupled with other elements, especially if the heat pump unit has not just one stage 208, but two stages, as is exemplified in the Fig. 3A, 3B, 4A, 5, 6A to 6D are shown. However, it should be noted that the heat pump unit can have any number of stages, for example, instead of two stages, it can also have three, four, five, etc. stages.

[0052] At the in Fig. In the embodiment shown in Figure 2A, the inlet and outlet of the first heat exchanger are arranged vertically or at least at an angle of less than 45° to the vertical in the operating position. Furthermore, a suction side of the pump 208 is connected to the heat pump unit via the pipe 228 and, in this example, to the evaporator outlet 220. It should also be noted that, during operation, the working fluid flows from top to bottom in line 228, just as it does in line 234, as indicated by the arrows. Similarly, the inlet 242 to the second heat exchanger and the outlet 243 from the second heat exchanger are connected to pipes 234, 236, and 238, respectively, via the interposed pumps 208 and 210. These pipes are also arranged vertically as far as possible and in any case at an angle of less than 45°.This ensures optimal alignment of the heat pump system and, in particular, of its individual components, because the suction sides of pumps 208 and 210 are each arranged in a vertically oriented downpipe 228 and 234, respectively. This results in optimal back pressure upstream of each pump, allowing pumps 208 and 210 to operate with little or no cavitation.

[0053] Furthermore, it is preferred that the heat exchangers 212 and 214 are arranged horizontally. This has the advantage that no air pockets form in the heat exchangers when the system is filled, meaning the heat exchangers are self-venting. Horizontal orientation also means that the heat exchangers are cuboidal, and thus have a base area that is smaller than the side area. Heat exchanger 212 and heat exchanger 214 therefore have an elongated shape, with the longer side of the cuboid arranged horizontally or at an angle of less than 45° to the horizontal.

[0054] Furthermore, it should be noted that the two pumps 208 and 210 are located closer to the first heat exchanger and the second heat exchanger 214, respectively, than to a connection point on the heat pump unit. This means that pipe 228 is longer than pipe 230, and that pipe 234 is also longer than pipe 236.

[0055] Furthermore, the heat pump unit is designed such that at least one inlet or outlet of an evaporator or condenser of a heat pump stage, which is connected to the first heat exchanger or the second heat exchanger, is arranged to exit the heat pump stage vertically downwards in the operating position or at an angle of less than 45° from a vertical. The outlets 220, 234 and the inlets 222, 226 are shown vertically, with this position being preferred. In addition, the heat pump stage 200 is preferably designed in the staggered arrangement, as also shown in Fig. As described in Figure 1, a steam supply channel 250, through which steam is directed from the evaporator 202 to the compressor 204, extends into the corresponding condenser. Furthermore, the heat pump stage 200 is preferably configured in the staggered arrangement shown in Figure 1. Fig. As described in Figure 1, a steam supply channel 250, through which steam is directed from the evaporator 202 to the compressor 204, extends through the condenser 206. Furthermore, the steam supply channel between the compressor 204 and the condenser 206, which is shown at Figure 251, is located above the condenser 206.

[0056] Furthermore, the liquefier 204, as it is in Fig. As shown in 2A, it is also arranged so that it extends above the condenser 206, so that in an off state, working fluid flows away from the compressor due to gravity. The compressor is therefore in a dry state when the heat pump stage 200 is deactivated, which occurs when the compressor motor 204 is switched off.

[0057] Furthermore, it should be noted that water is preferably used as the working medium, with the at least one heat pump stage being designed to maintain a pressure at which the water can evaporate at temperatures below 50 °C. This is particularly relevant in the two-stage arrangement, which will be discussed later. Fig. As indicated in sections 3A, 3B, 4A, 6A to 6D and 5, evaporation in the first heat pump stage will take place, for example, at temperatures of 20 °C to 30 °C, and evaporation in the second heat pump stage will take place, for example, at temperatures between 40 °C and 50 °C. Depending on the implementation, however, the temperatures may be lower, as illustrated by the following example: Fig. 8 or Fig. 7C is shown.

[0058] Preferably, the entire heat pump system is mounted on a support frame, which is not shown. In particular, the first and second heat exchangers 212, 214 are attached to the bottom of the support frame. Furthermore, the first pump and the second pump are connected to each other by a pump holder and are attached to the support frame above the first and second heat exchangers 212, 214 as a pump module. The at least one heat pump stage is then arranged above the pump holder.

[0059] In preferred embodiments, the heat pump system is designed with two stages and has a height of less than 2.50 m, a width of less than 2 m and a depth of less than 1 m.

[0060] Fig. Figure 2A shows the first aspect, where the heat pump system has the heat exchangers arranged at a lower end.

[0061] In contrast, it shows Fig. 2B the second aspect, in which the pumps are arranged at the very bottom and, in preferred implementations of the second aspect, the heat exchangers 212, 214 are arranged vertically and / or next to the pumps. In particular, according to the second aspect in Fig. Figure 2B shows a heat pump system that has heat pump stage 200 with the first compressor 204, the first condenser 206 and the first evaporator 202. Furthermore, as is also shown in Fig. As shown in Figure 2A, an expansion device 207 is provided to equalize the fluid level between the condenser 206 and the evaporator 202. Furthermore, the first heat exchanger 212 and the second heat exchanger 214 are assigned to a side to be cooled and a side to be heated, respectively. Additionally, the first pump 208 and the second pump 210 are provided, with the first pump 208 being coupled to the first heat exchanger 212 and the second pump 210 being coupled to the second heat exchanger 214. Again, the heat pump system has an operating position as shown schematically in Figure 2A. Fig. 2B is shown.

[0062] The first and second pumps are located below the heat pump unit 200 at the lower end of the heat pump system in the operating position. Furthermore, in the operating position, the first and second heat exchangers are also located below the heat pump unit at the lower end, next to pumps 208 and 210, as shown schematically in [Figure]. Fig. Figure 2B shows the following. In particular, the first pump 208 and the second pump 210 are arranged such that one pumping direction of each pump is horizontal in the operating position or deviates from the horizontal by a maximum of ± 45°. Furthermore, the two heat exchangers 212, 214, or at least one of the two heat exchangers 212, 214, are arranged vertically, wherein the first connection 240, 242 of the first and second heat exchanger 212, 214 is coupled to a pumping side of the respective pump 208, 210, and wherein the second connection 241, 243 of the first and second heat exchanger 212 and 214, respectively, is arranged above the respective first connection 240, 242 of the corresponding heat exchanger. In other words, the heat exchanger 212 is arranged such that the second connection 241, which represents the outlet from the first heat exchanger 212, is located above the first connection 240, which represents the inlet, in the direction of operation.Accordingly, in the second heat exchanger 214, the outlet, i.e., the second connection 243, is located above the inlet 242, or the first connection 242 of the second heat exchanger 214, in its operating position. The vertical arrangement is advantageous because it prevents air inclusions when filling the heat exchangers. Furthermore, the vertical position of the heat exchanger makes the pipe connection, and in particular the pipe 232 or 238, shorter compared to a horizontal arrangement. This is because the length of the heat exchanger essentially serves as the connecting pipe. Thus, the heat exchanger is used not only as a heat exchanger element but also as a connecting pipe.

[0063] Furthermore, the pumps are arranged as low as possible, preferably horizontally, so that the necessary back pressure upstream of the pump's suction side is readily achieved by a maximally long vertical pipe upstream of the pump, given a specific overall height of the heat pump system, thus preventing pump cavitation. The first pipe 228, through which the evaporator outlet 220 is connected to the suction side of the pump 208, also includes a bend, preferably located closer to the suction side of the pump 208 than to the evaporator outlet 220. Similarly, the bend in the second pipe 234, running from the condenser outlet 224 to the suction side of the pump 210, is also located closer to the pump than to the condenser outlet 224, in order to provide the longest possible vertical section through which the necessary back pressure is achieved, thus ensuring that the descending working fluid already receives a significant boost in kinetic energy.

[0064] Fig. 3A shows a third aspect of a heat pump system, whereby the third-stage heat pump system can have any arrangement of pumps or heat exchangers, but as can still be seen from the Fig. 3B, Fig. 4A, Fig. As outlined in section 5, the arrangement according to the first aspect is preferred. Alternatively, however, the arrangement according to the second aspect, i.e., with pumps arranged as far below as possible and preferably vertical heat exchangers, can also be used.

[0065] In particular, a heat pump system, such as those used in Fig. Figure 3A shows a heat pump stage 200, i.e., stage n+1, comprising a first evaporator 202, a first compressor 204, and a first condenser 206. The evaporator 202 is coupled to the compressor 204 via the vapor channel 250, and the compressor 204 is coupled to the condenser 206 via the vapor channel 251. It is preferred to use the interleaved arrangement, but any arrangement can also be used in the heat pump stage 200. Depending on the implementation, the inlet 222 to the evaporator 202 and the outlet 220 from the evaporator 202 are connected either to a region to be cooled, to a heat exchanger (such as the heat exchanger 212 to the region to be cooled), or to another previously arranged heat pump stage, for example, heat pump stage n, where n is an integer greater than or equal to zero.

[0066] Furthermore, the heat pump system in Fig. 3A a further heat pump stage 300, i.e., stage n+2, with a second evaporator 302, a second compressor 304, and a second condenser 306. In particular, the outlet 224 of the first condenser is connected to an evaporator inlet 322 of the second evaporator 320 via a connecting line 332. Depending on the implementation, the outlet 320 of the evaporator 302 of the further heat pump stage 300 can be connected to the inlet of the condenser 206 of the first heat pump stage 200, as shown by a dashed connecting line 334. However, the outlet 320 of the evaporator 302 can also be connected, as shown by the Fig. 4A, 6A to 6D and 5, shown, can be connected to a controllable path module to achieve alternative implementations. However, a cascade connection is generally achieved due to the fixed connection of the condenser outlet 224 of the first heat pump stage with the evaporator inlet 322 of the subsequent heat pump stage.

[0067] This sequential arrangement ensures that each heat pump stage operates with the smallest possible temperature difference, meaning the smallest possible difference between the heated and cooled working fluid. By connecting these heat pump stages in series, a sufficiently large overall temperature difference is achieved. This overall temperature difference is thus divided into several individual temperature differences. The sequential arrangement is particularly advantageous because it allows for significantly more efficient operation. The compressor power consumption for two stages, each handling a smaller temperature difference, is lower than the compressor power consumption for a single heat pump stage, which must achieve a large temperature difference.Furthermore, the requirements for the individual components are less demanding from a technical point of view when two stages are connected in series.

[0068] As it is in Fig. As shown in Figure 3A, the condenser outlet 324 of the condenser 306 of the further heat pump stage 300 can be coupled to the area to be heated, as is the case, for example, with reference to Fig. 3B is shown using the heat exchanger 214. Alternatively, however, the outlet 324 of the condenser 306 of the second heat pump stage can also be coupled via a connecting pipe to an evaporator of a further heat pump stage, i.e. the (n+3) heat pump stage. Fig. 3A thus shows, depending on the implementation, a cascade of, for example, four heat pump stages when n=1. However, if n is taken arbitrarily, it shows Fig. 3A a chain connection of any number of heat pump stages, wherein in particular the chain connection of the heat pump stage (n+1), which is designated by 200, and the further heat pump stage 300, which is designated by (n+2), is designed in more detail and the n- heat pump stage as well as the (n+3)- heat pump stage can also be designed not as a heat pump stage, but as a heat exchanger or as an area to be cooled or heated.

[0069] Preferably, as is the case, for example, in Fig. As shown in 3B, the condenser of the first heat pump stage 200 is arranged above the evaporator 302 of the second heat pump stage, so that the working fluid flows through the connecting line 332 due to gravity. This is particularly relevant in the case of the Fig. In the specific implementation of the individual heat pump stages shown in Figure 3B, the condenser is already located above the evaporator. This implementation is particularly advantageous because, even with heat pump stages aligned with each other, the fluid already flows from the condenser of the first stage into the evaporator of the second stage via the connecting line 332. However, it is also preferred to achieve a height difference of at least 5 cm between the top edge of the first stage and the top edge of the second stage. This dimension, shown in Figure 340, Fig. As shown in Figure 3B, the distance is preferably 20 cm, since this ensures optimal water flow from the first stage 200 to the second stage 300 via the connecting line 332 for the described implementation. This also eliminates the need for a special pump in the connecting line 332, thus saving the pump's capacity. Only the intermediate circuit pump 330 is required to return the working fluid from the outlet 320 of the evaporator of the second stage 300, which is located lower than the first stage, to the condenser of the first stage, i.e., to the inlet 226. For this purpose, the outlet 320 is connected to the suction side of the pump 330 via the pipe 334. The pump side of the pump 330 is connected to the inlet 226 of the condenser via the pipe 336. Fig. The chain connection of the two stages shown in 3B corresponds to Fig. 3A with connection 334. Preferably, the intermediate circuit pump 330 is also arranged at the bottom, like the other two pumps 208 and 210, since cavitation can then also be prevented in the intermediate circuit line 334, because sufficient back pressure of the pump is achieved due to the placement of the intermediate circuit pump 330 in the downpipe 334.

[0070] Although in Fig. 3B where the configuration according to the first aspect is shown, i.e., 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 has been shown according to the second aspect.

[0071] As it is in Fig. As shown in Figure 3B, the first stage comprises the expansion element 207 and the second stage an expansion element 307. However, since working fluid already exits the condenser 206 of the first stage via the connecting line 332, the expansion element 207 is unnecessary. In contrast, the expansion element 307 is preferably used in the lower stage. Thus, in one embodiment, the first stage can be built without an expansion element, and only an expansion element 307 is provided in the second stage. However, since it is preferred to construct all stages identically, the expansion element 207 is also provided in the heat pump stage 200. If the same is implemented to support nucleate boiling, the expansion element 207 is also helpful despite the fact that it may not necessarily direct liquefied working fluid into the evaporator, but only heated steam.

[0072] Nevertheless, it has turned out that in the Fig. The working fluid accumulates in the evaporator 302 of the second heat pump stage 300, as shown in the arrangement 3B. It is therefore, as shown in Fig. As shown in Figure 5, a measure has been taken to transfer working fluid from the evaporator 302 of the second heat pump stage 300 into the evaporator circuit of the first stage 200. For this purpose, an overflow arrangement 502 is provided in the second evaporator 302 of the second heat pump stage to discharge working fluid from the second evaporator 302 once a predefined maximum working fluid level is reached. Furthermore, a fluid line 504, 506, 508 is provided, which is coupled on one side to the overflow arrangement 502 and on the other side to a suction side of the first pump 208 at a coupling point 512. A pressure reducer 510 is provided at the coupling point 512, which is preferably designed as a Bernoulli pressure reducer, i.e., as a pipe or hose constriction. The fluid line comprises a first connecting section 504, a U-shaped section 506, and a second connecting section 508.Preferably, the U-shaped section 506 has a vertical height in the operating position of at least 5 cm and preferably 15 cm. This creates a self-regulating system that operates without a pump. If the water level in the evaporator 302 of the lower tank 300 is too high, working fluid flows into the U-tube 506 via the connecting line 504. The U-tube is connected to the suction side of the pump 208 at the coupling point 512 on the pressure reducer via the connecting line 508. Due to the increased flow velocity upstream of the pump caused by the constriction 510, the pressure drops, and water from the U-tube 506 can be drawn in. A stable water level is established in the U-tube, which is sufficient to compensate for the pressure upstream of the pump at the constriction and in the evaporator of the lower tank. At the same time, however, the U-tube 506 acts as a steam barrier, preventing steam from the evaporator 302 from entering the suction side of the pump 208. The expansion devices 207 and 208, respectively,307 are preferably also designed as overflow arrangements to transfer working fluid into the respective evaporator when a predetermined level in a condenser is exceeded. This ensures that the fill levels of all containers, i.e., all condensers and evaporators in both heat pump stages, are automatically and automatically regulated without effort or pumps.

[0073] This is particularly advantageous because it allows heat pump stages to be switched on or off depending on the operating mode.

[0074] Fig. 4A and Fig. Figure 5 already shows a detailed representation of a controllable path module based on the upper 2x2-way switch 421 and the lower 2x2-way switch 422. Fig. Figure 4B shows a general implementation of the controllable path module 420, which can be implemented by the two serially connected 2x2-way switches 421 and 422, but can also be implemented alternatively.

[0075] The controllable path module 420 from Fig. 4B is coupled to a controller 430 so that it can be controlled by it via a control line 431. The controller receives sensor signals 432 as input signals and outputs pump control signals 436 and / or compressor motor control signals 434. The compressor motor control signals 434 lead to the compressor motors 204, 304, as used, for example, in Fig. 4A are shown, and the pump control signals 436 lead to pumps 208, 210, 330. Depending on the implementation, however, pumps 208, 210 can be run continuously, i.e., uncontrolled, because they are already present in each of the [units / systems] based on the Fig. 7A, Fig. The operating modes described in section 7B are running. Only the intermediate circuit pump 330 could therefore be controlled by a pump control signal 436.

[0076] The controllable path module 420 comprises a first input 401, a second input 402, and a third input 403. As it is used, for example, in Fig. As shown in Figure 4A, the first input 401 is connected to the outlet 241 of the first heat exchanger 212. Furthermore, the second input 402 of the controllable directional control module is connected to the return or outlet 243 of the second heat exchanger 214. Additionally, the third input 403 of the controllable directional control module 420 is connected to one pump side of the intermediate circuit pump 330.

[0077] A first output 411 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. Furthermore, 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.

[0078] The various input / output connections achieved through the controllable path module 420 are in Fig. 4C shown.

[0079] In one mode, the high-performance mode (HLM), the first input 401 is connected to the first output 411. Furthermore, the second input 402 is connected to the third output 413. Additionally, the third input 403 is connected to the second output 412, as shown in line 451 of Fig. 4C is shown.

[0080] In medium-load mode (MLM), where only the first stage is active and the second stage is inactive (i.e., the compressor motor 304 of the second stage 300 is switched off), the first input 401 is connected to the first output 411. Furthermore, the second input 402 is connected to the second output 412. Additionally, 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 (i.e., input 401 to output 412). Furthermore, the second input 402 is connected to the first output 411. Finally, the third input 403 is connected to the third output 413.

[0081] In low-power mode (NLM), shown in line 454, the first input 401 is connected to the third output 413. Furthermore, the second input 402 is connected to the first output 411. Finally, the third input 403 is connected to the second output 412.

[0082] It is preferred to implement the controllable path module by means of the two series-arranged 2-way switches 421 and 422, as they are used, for example, in Fig. 4A are shown, or as they are also shown in the Fig. Figures 6A to 6D are shown. The first two-way switch 421 has the first input 401, the second input 402, the first output 411, and a second output 414, which is connected via an intermediate connection 406 to an input 404 of the second two-way switch 422. This second two-way switch has the third input 403 as an additional input, the second output 412 as an output, and the third output 413 also as an output.

[0083] The positions of the two 2x2-way switches 421 are in Fig. 7B presented in tabular form. Fig. Figure 6A shows the two positions of switches 421 and 422 in high-power mode (HLM). This corresponds to the first line in Fig. 7B. Fig. Figure 6B shows the position of the two switches in medium-power mode. The upper switch 421 is exactly the same in medium-power mode as in high-power mode. Only the lower switch 422 has been changed. In free-cooling mode, which is in Fig. As shown in Figure 6C, the lower switch is the same as in medium-power mode. Only the upper switch has been changed. In low-power mode, the lower switch 422 is changed compared to free-cooling mode, while the upper switch remains in its position in low-power mode. This ensures that only one switch needs to be changed when switching from one adjacent mode to the next, while the other switch can remain in its original position. This simplifies the entire switching process from one operating mode to the next.

[0084] Fig. Figure 7A shows the activity of the individual compressor motors and pumps in the different modes. In all modes, the first pump (208) and the second pump (210) are active. The intermediate circuit pump is active in high-performance, medium-performance, and free-cooling modes, but is deactivated in low-performance mode.

[0085] The first-stage compressor motor 204 is active in high-performance mode, medium-performance mode, and free-cooling mode, and is deactivated in low-performance mode. Furthermore, the second-stage compressor motor is only active in high-performance mode, but is deactivated in medium-performance mode, free-cooling mode, and low-performance mode.

[0086] It should be noted that Fig. 4A represents the low-power mode in which both motors 204 and 304 are deactivated, and in which the intermediate circuit pump 330 is also activated. In contrast, Fig. 3B is the high-performance mode that is, in a sense, permanently coupled, in which both motors and all pumps are active. Fig. 5 again shows the high-performance mode, in which the switch positions are such that exactly the configuration according to Fig. 3B will be received.

[0087] Fig. 6A and Fig. Figure 6C further shows various temperature sensors. A sensor 602 measures the temperature at the outlet of the first heat exchanger 212, i.e., at the return from the side to be cooled. A second sensor 604 measures the temperature at the return from the side to be heated, i.e., from the second heat exchanger 214. Furthermore, another temperature sensor 606 measures the temperature at the outlet 220 of the first-stage evaporator, which is typically the coldest temperature. In addition, another temperature sensor 608 is provided, which measures the temperature in the connecting line 332, i.e., at the outlet of the first-stage condenser, which is designated 224 in other figures. Furthermore, the temperature sensor 610 measures the temperature at the outlet of the second-stage evaporator 300, i.e., at outlet 320 of the evaporator 300. Fig. 3B, for example.

[0088] Finally, the temperature sensor 612 measures the temperature at the output 324 of the condenser 306 of the second stage 300, with this temperature being the warmest temperature in the system in full power mode.

[0089] The following refers to the Fig. 7C and Fig. 7D to the different stages or operating modes of the heat pump system, as can be seen, for example, from the Fig. The information is presented in 6A to 6D, and is also presented using the other figures.

[0090] German patent DE 10 2012 208 174 A1 discloses a heat pump with a free cooling mode. In free cooling mode, the evaporator inlet is connected to a return flow from the area to be heated. Furthermore, the condenser inlet is connected to a return flow from the area to be cooled. The free cooling mode already achieves a significant increase in efficiency, particularly for outside temperatures below, for example, 22 °C.

[0091] This free cooling mode (FKM) is described in line 453 in Fig. 4C is shown and is particularly in Fig. Figure 6C shows that the outlet of the refrigeration-side heat exchanger is connected to the inlet of the first-stage condenser. Furthermore, the outlet of the heating-side heat exchanger 214 is coupled to the evaporator inlet of the first stage, and the inlet of the heating-side heat exchanger 214 is connected to the condenser outlet of the second stage 300. However, the second stage is deactivated, so the condenser outlet 338 of Fig. For example, 6C has the same temperature as the condenser inlet 413. Furthermore, the evaporator outlet 334 of the second stage also has the same temperature as the condenser inlet 413 of the second stage, so that the second stage 300 is thermodynamically "short-circuited" in a sense. However, this stage is still being used by working fluid, even though the compressor motor is deactivated. The second stage is therefore still used as part of the infrastructure, but is deactivated due to the switched-off compressor motor.

[0092] If, for example, a switch is required from medium-performance mode to high-performance mode – i.e., from a mode in which the second stage is deactivated and the first stage is active, to a mode in which both stages are active – it is preferred to first run the compressor motor for a certain period of time, which is, for example, greater than one minute and preferably 5 minutes, before switching the switch 422 from the Fig. 6B switch position shown in the Fig. The switch position shown in 6A is changed.

[0093] A heat pump, according to one aspect, comprises an evaporator with an evaporator inlet and an evaporator outlet, and a condenser with a condenser inlet and a condenser outlet. Furthermore, a switching device is provided to operate the heat pump in one or another operating mode. In one operating mode, the low-load mode, the heat pump is completely bypassed, such that the return flow from the area to be cooled is directly connected to the supply flow from the area to be heated. In this bypass or low-load mode, the return flow from the area to be heated is also connected to the supply flow from 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.

[0094] In the bypass mode, the evaporator is not connected to the area to be cooled, nor is the condenser; instead, both areas are effectively "short-circuited." In the second alternative operating mode, the heat pump is not bypassed but, at relatively low temperatures, typically operates in free cooling mode, or in normal mode with one or two stages. In free cooling mode, the switching device is configured to connect a return flow from the area to be cooled to the condenser inlet and a return flow from the area to be heated to the evaporator inlet. In contrast, in normal mode, the switching device is configured to connect the return flow from the area to be cooled to the evaporator inlet and the return flow from the area to be heated to the condenser inlet.

[0095] Depending on the design, a heat exchanger can be provided at the outlet of the heat pump (condenser side) or at the inlet (evaporator side) to decouple the internal heat pump circuit from the external circuit. In this case, the evaporator inlet represents the inlet of the heat exchanger, which is coupled to the evaporator. Furthermore, in this case, the evaporator outlet represents the outlet of the heat exchanger, which is also rigidly coupled to the evaporator.

[0096] Similarly, on the condenser side, the condenser outlet is a heat exchanger outlet and the condenser inlet is a heat exchanger inlet, specifically on the side of the heat exchanger that is not directly coupled to the actual condenser.

[0097] Alternatively, the heat pump can be operated without an inlet or outlet heat exchanger. In this case, for example, a heat exchanger could be provided at the inlet to the area to be cooled or at the inlet to the area to be heated, each comprising the return or supply flow to the cooling area or the heating area, respectively.

[0098] In preferred embodiments, the heat pump is used for cooling, so that the area to be cooled is, for example, a room in a building, a computer room, or generally a cold storage room, while the area to be heated is, for example, the roof of a building or a similar location where a heat dissipation device can be placed to release heat to the environment. However, if the heat pump is used for heating instead, then the area to be cooled is the environment from which energy is to be extracted, and the area to be heated is the "useful application," i.e., for example, the interior of a building, a house, or a room to be heated.

[0099] The heat pump is therefore able to switch from the bridging mode either to the free cooling mode or, if such a free cooling mode is not available, to the normal mode.

[0100] In general, the heat pump is advantageous in that it becomes particularly efficient when outside temperatures are, for example, lower than 16 °C, which is often the case at least in the northern and southern hemispheres far from the equator.

[0101] This ensures that the heat pump can be completely switched off when outside temperatures allow for direct cooling. In the case of a heat pump with a radial compressor between the evaporator and the condenser, the radial impeller can be stopped, eliminating the need to input any further energy into the heat pump. Alternatively, the heat pump can still operate in a standby mode or similar, which, being only a standby mode, results in minimal power consumption. Particularly with valveless heat pumps, which are the most commonly used, completely bypassing the heat pump prevents a thermal short circuit, unlike in free cooling mode.

[0102] Furthermore, it is preferred that in the first operating mode, i.e., in the low-power or bridging mode, the switching device completely isolates the return flow of the area to be cooled or the supply flow of the area to be cooled from the evaporator, so that no liquid connection exists between the inlet or outlet of the evaporator and the area to be cooled. This complete isolation will also be advantageous on the condenser side.

[0103] In this implementation, a temperature sensor is provided that detects a first temperature relative to the evaporator or a second temperature relative to the condenser. Furthermore, the heat pump has a controller that is coupled to the temperature sensor and is designed to control the switching device based 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 switching device can be implemented using an input switch and an output switch, each with four inputs and four outputs, which can be switched depending on the mode. Alternatively, the switching device can also be implemented using several individual, cascaded switches, each with one input and two outputs.

[0104] Furthermore, the coupling element for connecting the bypass line to the flow into the area to be heated, or the coupler for connecting the bypass line to the flow into the area to be cooled, can be designed as a simple three-terminal combination, i.e., as a liquid adder. However, in implementations, it is preferred to also design the couplers as changeover switches or integrated into the input or output switch to achieve optimal decoupling.

[0105] Furthermore, a primary temperature sensor is used on the evaporator side, and a secondary temperature sensor is used on the condenser side, with the more direct measurement being preferred. The evaporator-side measurement is used in particular to control the speed of the temperature booster, e.g., a compressor in the first and / or second stage, while the condenser-side measurement, or even an ambient temperature measurement, is used to control the operating mode. This allows the heat pump to switch from bridging mode to free cooling mode, for example, when the temperature is no longer in the very cold range but in the moderately cold range.However, if the temperature is higher, i.e., in a warm temperature range, the switching device will put the heat pump into a normal mode with the first active stage or with two active stages.

[0106] In a two-stage heat pump, during this normal mode, which corresponds to medium-performance mode, only the first stage is active, while the second stage remains inactive, meaning it is not supplied with power and therefore consumes no energy. Only when the temperature rises further, reaching a very warm level, is a second pressure stage activated in addition to the first heat pump stage (or pressure stage). This second pressure stage comprises an evaporator, a temperature booster (typically a radial compressor), and a condenser. The second pressure stage can be connected in series, parallel, or both with the first pressure stage.

[0107] To ensure that, during bridging mode (i.e., when outside temperatures are already relatively cold), the cold from outside doesn't completely penetrate the heat pump system and, consequently, the room being cooled, thus making it even colder than it should be, it is preferable to provide a control signal via a sensor signal at the supply line to or return line of the area being cooled. This signal can be used by a heat transfer device located outside the heat pump to control heat output, i.e., to reduce it when temperatures become too low. The heat transfer device is, for example, a liquid-to-air heat exchanger with a pump to circulate the liquid supplied to the area being heated. Furthermore, the heat transfer device can include a fan to transport air into the air heat exchanger.Additionally or alternatively, a three-way mixing valve can be used to partially or completely bypass the air heat exchanger. Depending on the supply line to the area to be cooled, which in this bypass mode is connected not to the evaporator outlet but to the return line from the area to be heated, the heat output device, such as the pump, fan, or three-way mixing valve, is controlled to continuously reduce heat output. This ensures that a temperature level is maintained in both the heat pump system and the area to be cooled, which in this case can be above the outside temperature. This allows the waste heat to even be used to heat the "cooled" space if the outside temperatures are too low.

[0108] In another aspect, the entire heat pump control system is configured such that, depending on a temperature sensor output signal from an evaporator-side temperature sensor, a "fine control" of the heat pump is performed. This includes speed control in the various modes, such as free cooling mode, normal mode with first stage, and normal mode with second stage, as well as control of the heat distribution unit in bridging mode. Meanwhile, a coarse control is achieved based on a temperature sensor output signal from a condenser-side temperature sensor. Thus, a mode switch from bridging mode (or NLM) to free cooling mode (or FKM) and / or normal mode (MLM or HLM) is performed solely based on the condenser-side temperature sensor. The evaporator-side temperature output signal is not used to determine whether a switch occurs.However, for the speed control of the radial compressor or for the control of the heat dissipation devices, only the evaporator-side temperature output signal is used, but not the condenser-side sensor output signal.

[0109] It should be noted that the various aspects of the present invention relating to the arrangement and the two-stage design, as well as relating to the use of the bridging mode, the control of the heat dissipation device in the bridging mode or free cooling mode, and the control of the radial compressor in the free cooling mode or the normal operating mode, or relating to the use of two sensors, wherein one sensor is used for switching the operating mode and the other sensor for fine control, can be used independently of one another. However, these aspects can also be used in pairs, in larger groups, or combined together.

[0110] Fig. 7A to 7D show an overview of different modes in which the heat pump operates according to Fig. 1, Fig. 2, Fig. 8A, Fig. 9A is operable. If the temperature of the area to be heated is very cold, for example 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 emission device in the area to be heated 16 is generated. If the temperature of the area to be heated, i.e., area 16 of Fig. If the ambient temperature is moderately cold, for example between 16°C and 22°C, the operating mode control will activate free cooling mode. In this mode, due to the small temperature difference, the first stage of the heat pump can operate at low power. However, if the temperature of the area to be heated is warm, for example between 22°C and 28°C, the heat pump will operate in normal mode, but with only one heat pump stage active. Conversely, if the outside temperature is very warm, between 28°C and 40°C, a second heat pump stage will be activated. This second stage also operates in normal mode and continuously supports the first stage.

[0111] Preferably, a speed control or “fine control” of a radial compressor is integrated within the temperature booster 34. Fig. 1. Temperature ranges “medium cold”, “warm”, “very warm” were set to ensure that the heat pump always operates with the heating / cooling output required by the actual conditions.

[0112] 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.

[0113] It should be noted that the temperature ranges "very cold", "moderately cold", "warm", and "very warm" represent different temperature ranges, with the average temperature increasing from very cold to moderately cold, to warm, and to very warm. These ranges can be further defined by... Fig. As shown in Figure 7C, the areas are directly adjacent to one another. In some embodiments, however, the areas can also overlap and be at the aforementioned temperature level or at a different, overall higher or lower temperature level. Furthermore, the heat pump is preferably operated with water as the working fluid. Depending on the requirements, however, other fluids can also be used.

[0114] This is in Fig. Figure 7D is shown in tabular form. If the condenser temperature is in a very cold temperature range, the first operating mode is activated by the controller 430. If, in this mode, the evaporator temperature is detected to be lower than a setpoint temperature, a control signal is sent to the heat dissipation unit, resulting in a reduction of heat output. However, if the condenser temperature is in the moderately cold range, the controller 430 will switch to free cooling mode, as indicated by lines 431 and 434. If the evaporator temperature is higher than a setpoint temperature in this mode, the radial compressor speed is increased via control line 434.If it is detected that the condenser temperature is in a warm range, the first stage is switched to normal operation, triggered by a signal on line 434. If, however, it is detected that the evaporator temperature is still higher than a setpoint temperature at a certain compressor speed, the speed of the first stage is increased, again via the control signal on line 434. Finally, if it is detected that the condenser temperature is in a very warm range, a second stage is switched on for normal operation, again triggered by a signal on line 434.Depending on whether the evaporator temperature is higher or lower than a setpoint temperature, as indicated by signals on line 432, the first and / or second stage is then controlled to react to a changed situation.

[0115] This results in transparent and efficient control, achieving both a "coarse adjustment" through mode switching and a "fine adjustment" through temperature-dependent speed control, ensuring that only the amount of energy actually required is consumed. This approach, which also avoids the constant on / off cycling of the heat pump, as is common with heat pumps that use hysteresis, also guarantees that no start-up losses occur due to continuous operation.

[0116] Preferably, a speed control or "fine control" of a radial compressor is implemented within the compressor motor. Fig. 1. Temperature ranges “medium cold”, “warm”, “very warm” were set to ensure that the heat pump always operates with the heating / cooling output required by the actual conditions.

[0117] 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.

[0118] During a mode change, the controller 430 is designed to detect a condition for transitioning from the medium-capacity mode to the high-capacity module. The compressor 304 is then started in the subsequent heat pump stage 300. Only after a predetermined time, greater than one minute and preferably greater than four or even five minutes, has elapsed will the controllable directional control module switch from the medium-capacity mode to the high-capacity mode. This ensures that switching can be performed easily from a standstill, with the compressor motor running before the switchover guaranteeing that the pressure in the evaporator is lower than the pressure in the compressor.

[0119] It should be noted that the temperature ranges in Fig. The temperature can vary by 7°C. In particular, the threshold temperatures between a very cold temperature and a moderately cold temperature, i.e., the value 16°C, are... Fig. 7C as well as between the moderately cold temperature and the warm temperature, i.e. the value 22 °C in Fig. 7C and the value between the warm and the very warm temperature, i.e. the value 28 °C in Fig. 7C is merely an example. Preferably, the threshold temperature between warm and very warm, at which a switch from medium-power mode to high-power mode occurs, is between 25 and 30 °C. Furthermore, the threshold temperature between warm and medium-cold, i.e., when switching between free-cooling mode and medium-power mode, is in a temperature range between 18 and 24 °C. Finally, the threshold temperature at which a switch occurs between medium-cold mode and very-cold mode, is in a range between 12 and 20 °C, the values ​​preferably being selected as shown in the table in Fig. 7C are shown, however, as mentioned, they can be adjusted differently in the areas mentioned.

[0120] Depending on the implementation and requirements profile, the heat pump system can also be operated in four different operating modes, which are all on a different absolute level, so that the terms "very cold", "medium cold", "warm", "very warm" are only to be understood relative to each other, but do not represent absolute temperature values.

[0121] Although certain elements are described as device elements, it should be noted that this description can equally be viewed as a description of steps in a process and vice versa. For example, the elements described in the Fig. The block diagrams described in 6A to 6D are equally flowcharts of a corresponding method according to the invention.

[0122] Furthermore, it should be noted that the control is, for example, by element 430 in Fig. 4B can be implemented as software or hardware, and this also applies to the tables in the Fig. 4C, Fig.4D, or 7A, 7B, 7C, 7D applies. The control system can be implemented on a non-volatile storage medium, a digital or other storage medium, in particular a floppy disk or CD with electronically readable control signals that can interact with a programmable computer system to execute the corresponding method for pumping heat or operating a heat pump. In general, the invention thus also includes a computer program product with program code stored on a machine-readable medium for carrying out the method, provided the computer program product runs on a computer. In other words, the invention can also be realized as a computer program with program code for carrying out the method, provided the computer program runs on a computer.

Claims

[1] Heat pump system with the following features: a heat pump unit with at least one heat pump stage (200), wherein the at least one heat pump stage (200) comprises an evaporator (202), a compressor (204) and a condenser (206); 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); and a second pump (210) which is coupled to the second heat exchanger (214), wherein the heat pump system has an operating position, wherein in the operating position the first pump (208) or the second pump (210) is arranged above the first heat exchanger (212) or the second heat exchanger (214), and the heat pump unit is located above the first pump (208) and the second pump (210). [2] Heat pump system according to claim 1, wherein the first heat exchanger (212) has an inlet (240) and an outlet (241), wherein the inlet (240) and the outlet (241) are coupled to the heat pump unit, wherein the inlet (240) is arranged perpendicularly or at least at an angle of less than 45° to a perpendicular wherein a suction side of the first pump (208) is arranged in the inlet (228, 230, 240), and in which, during operation of the heat pump, a flow of working fluid flows from top to bottom through the inlet (228, 230, 240). [3] Heat pump system according to claim 1 or 2, wherein the second heat exchanger (214) has an inlet (242, 236, 234) and an outlet (243, 238), wherein the inlet (234, 236, 242) or the outlet (238, 243) is coupled to the heat pump unit, wherein the outlet or the inlet is arranged perpendicular or at least at an angle of less than 45° to a perpendicular, wherein a suction side of the second pump (210) is arranged in the inlet (234, 236, 242), and wherein, during operation, a flow of working fluid flows from top to bottom through the inlet. [4] Heat pump system according to one of the preceding claims, wherein the first heat exchanger (212) or the second heat exchanger (214) is arranged horizontally. [5] Heat pump system according to one of the preceding claims, wherein the first pump (208) or the second pump (210) are arranged closer to the first heat exchanger (212) or to the second heat exchanger (214) than to a connection point on the heat pump unit. [6] Heat pump system according to one of the preceding claims, wherein the heat pump unit is designed such that at least one outlet of the evaporator (202) or the condenser (206) of the at least one heat pump stage (200), which is connected to the first heat exchanger (212) or the second heat exchanger (214), is arranged such that it exits the at least one heat pump stage (200) in the operating position vertically downwards or at an angle of less than 45° from a vertical of the at least one heat pump stage (200). [7] Heat pump system according to one of the preceding claims, in which the heat pump unit is designed such that at least one inlet (222, 226) of the evaporator (202) or of the condenser (206) of the at least one heat pump stage (200), which is connected to the first heat exchanger (212) or the second heat exchanger (214), is designed such that it exits from the at least one heat pump stage (200) in the operating position vertically downwards or at an angle of less than 45° from a vertical from the at least one heat pump stage (200). [8] Heat pump system according to one of the preceding claims, wherein the at least one heat pump stage (200) is designed such that a steam intake channel (250) of the at least one heat pump stage (200) extends through the condenser (206). [9] Heat pump system according to one of the preceding claims, wherein the at least one heat pump stage (200) is designed such that the compressor (204) extends above the condenser (206), so that in an off state of the compressor (204) liquid runs away from the compressor (204) due to gravity. [10] Heat pump system according to one of the preceding claims, which is configured to use water as the working medium, wherein the at least one heat pump stage (200) is configured to maintain a pressure at which the water can evaporate at temperatures below 60 °C. [11] Heat pump system according to one of the preceding claims, further comprising the following features: a support frame, wherein the first heat exchanger (212) and the second heat exchanger (214) are attached to the bottom of the support frame, wherein the first pump (208) and the second pump (210) are attached to each other by a pump holder, and wherein the pump holder is attached to the support frame above the first heat exchanger (212) and the second heat exchanger (214), and wherein at least one heat pump stage (200) is arranged above the pump holder. [12] Heat pump system according to one of the preceding claims, wherein the heat pump unit comprises at least one heat pump stage (200) and a further heat pump stage (300). [13] Heat pump system according to one of the preceding claims, in which an evaporator outlet (220) of the at least one heat pump stage (200) is connected via a first downpipe (228) to a suction side of the first pump (208), wherein the downpipe is vertical in the operating position or has an angle of at most 45° to a vertical. [14] Heat pump system according to claim 12 or 13, wherein a condenser outlet (224) of the further heat pump stage (300) is connected via a second downpipe (338) to a suction side of the second pump (210), wherein the downpipe (338) is vertical in the operating position or has an angle of at most 45° to a vertical. [15] Heat pump system according to one of the preceding claims, in which a condenser outlet (224) of the at least one heat pump stage (200) is connected to an evaporator inlet (322) of the further heat pump stage (300) by an intermediate circuit pipe (332), wherein no pump is arranged in the intermediate circuit pipe (332), and wherein the at least one heat pump stage (200) and the further heat pump stage (300) are designed and arranged such that, during operation, a condenser working fluid level of the at least one heat pump stage (200) is higher than an evaporator working fluid level in the further heat pump stage (300). [16] Heat pump system according to one of claims 12 to 15, which further comprises an intermediate circuit pump (330) which is arranged below the at least one heat pump stage (200) and the further heat pump stage (300) and is connected to an evaporator outlet (320) of the further heat pump stage (300) via a downpipe (334) which is connected to a suction side of the intermediate circuit pump (330). [17] Heat pump system according to one of claims 12 to 16, in which the at least one heat pump stage (200) has the compressor (204) and the further heat pump stage (300) has a second compressor (304), wherein the respective compressor (204, 304) is arranged above the condenser (206) or a further condenser (306) of the further heat pump stage (300), and wherein the at least one heat pump stage (200) and the further heat pump stage (300) are arranged relative to each other such that a radial wheel of the second compressor (304) is arranged at least 5 cm lower than a radial wheel of the compressor (204). [18] Heat pump system according to one of claims 12 to 17, wherein the at least one heat pump stage (200) and the further heat pump stage (300) have an outer housing dimension which is the same within a tolerance of 5 cm, wherein the housing of the at least one heat pump stage (200) is arranged higher than the housing of the further heat pump stage (300), such that a bottom of the housing of the at least one heat pump stage (200) is higher than a bottom of the housing of the further heat pump stage (300). [19] Heat pump system according to claim 18, in which a controllable directional control module (420) is arranged below the at least one heat pump stage (200) and above the first pump (208), the second pump (210) or the intermediate circuit pump (330) to connect at least two inputs into the controllable directional control module (420) with at least two outputs from the controllable directional control module (420). [20] Heat pump system according to claim 19, wherein the controllable directional module (420) has the following connections: a return flow from the first heat exchanger (212) as the first inlet (404); a return flow from the second heat exchanger (214) as the second inlet (402); a pump side of the intermediate circuit pump (330) as the third input (403); an inlet to the evaporator (202) of which at least one heat pump stage (200) is the first outlet (411); an inlet to the condenser (206) of at least one heat pump stage (200) as a second outlet (412); and an inlet to the further condenser (306) of the further heat pump stage (300) as a third outlet (413), and wherein the controllable path module (420) is configured to connect one or more inputs to one or more outputs depending on a control signal (431). [21] Heat pump system according to claim 19 or 20, further comprising a control unit (430) for controlling the heat pump unit and the controllable directional module (420) to operate the heat pump system in one of at least two different modes, wherein the heat pump system is configured to perform at least two modes selected from a group of modes comprising the following modes: a high-performance mode in which at least one heat pump stage (200) and the other heat pump stage (300) are active; a medium-performance mode in which at least one heat pump stage (200) is active and the other heat pump stage (300) is inactive; a free cooling mode in which at least one heat pump stage (200) is active and the other heat pump stage (300) is inactive and the second heat exchanger (214) is coupled to an evaporator inlet (222) of at least one heat pump stage (200); and a low-power mode in which at least one heat pump stage (200) and the other heat pump stage (300) are inactive. [22] Heat pump system according to claim 21, in which the at least one heat pump stage (200) or the further heat pump stage (300) is inactive when a compressor motor (204, 304) of the corresponding heat pump stage is switched off. [23] Heat pump system according to claim 21 or 22, in which the first pump (208), the second pump (210) and the intermediate circuit pump (330) are active in high-performance mode, medium-performance mode and free-cooling mode, and in which, in low-power mode, the first pump (208) and the second pump (210) are active, and the intermediate circuit pump (330) is inactive. [24] Heat pump system according to one of claims 19 to 23, in which the controllable path module (420) is configured to connect the first input (401) to the first output (411) in a high-performance mode, to connect the second input (402) to a third output (413), and to connect the third input (403) to the second output (412), to connect the first input (401) to the first output (411), the second input (402) to the second output (412), and the third input (403) to the third output (413) in a medium power mode, to connect the first input (401) to the second output, the second input (402) to the first output, and the third input (403) to the third output in a free cooling mode, and to connect the first input (401) to the third output, the second input (402) to the first output, and the third input (403) to the second output (412) in a low-power mode. [25] Heat pump system according to one of claims 19 to 24, wherein the controllable path module (420) has a first changeover switch (421) with two switch positions and a second changeover switch (422) with two switch positions, wherein an output (14) of the first switch is connected to an input (404) of the second switch (406). [26] Heat pump system according to claim 25, wherein the two switch positions define four operating modes with different power levels, wherein when switching from one power level to the next higher or lower power level only one switch is switched and the other switch remains in its position. [27] Heat pump system according to one of claims 19 to 24, in which the controllable directional switch (420) has a first changeover switch (421) and a second changeover switch (422) each with two switch positions, wherein the first switch (421) has the following features: a first switch input which is connected to the first input (401), a second switch input that is coupled to the second input (402), a first switch output coupled to the first output (411), and a second switch output the second switch (422) has the following features: a first switch input that is coupled to the second switch output of the first switch (421), a second switch input that is coupled to the third input (413), a first switching output that is coupled to the second output (412), and a second switch output that is coupled to the third output (413). [28] Heat pump system according to claim 27, wherein the first changeover switch (421) is configured to connect the first changeover switch input to the first changeover switch output and to connect the second changeover switch input to the second changeover switch output in a first switch position, and to connect the first changeover switch input to the second changeover switch output in a second switch position, and to connect the second changeover switch input to the first changeover switch output, or wherein the second changeover switch (422) is configured to connect the first changeover switch input to the first changeover switch output in a first switch position, and to connect the second changeover switch input to the second changeover switch output, and to connect the first changeover switch input to the second changeover switch output in a second switch position, and to connect the second changeover switch input to the first changeover switch output. [29] Heat pump system according to claim 28, in which the controllable path module (420) is configured, to operate the first switch (421) in the first switch position in a high-performance mode, and to operate the second switch (422) in the first switch position, or to operate the first switch (421) in the first switch position and the second switch (422) in the second switch position in a medium power mode, or to operate the first switch (421) in the second switch position and the second switch (422) in the first switch position in a free cooling mode, or to operate the first switch (421) in the second switch position in a low-power mode, and to operate the second switch (422) in the second switch position. [30] Heat pump system according to one of the preceding claims, wherein the height of the heat pump system is less than 2.50 m, the width of the heat pump system is less than 2 m, and the depth of the heat pump system is less than 1 m. [31] Method for manufacturing a heat pump system with a heat pump unit having at least one heat pump stage (200), wherein the at least one heat pump stage (200) comprises an evaporator (202), a compressor (204) and a condenser (206); 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); and a second pump (210) coupled to the second heat exchanger (214), comprising the following steps: Arranging the first pump (208) or the second pump (210) above the first heat exchanger (212) or the second heat exchanger (214), and Position the heat pump unit above the first pump (208) and the second pump (210). [32] Method for operating a heat pump system with a heat pump unit having at least one heat pump stage (200), wherein the at least one heat pump stage (200) comprises an evaporator (202), a compressor (204) and a condenser (206); 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); and a second pump (210) coupled to the second heat exchanger (214), comprising the following steps: Bringing the heat pump system into an operating position, wherein in the operating position the first pump (208) or the second pump (210) is arranged above the first heat exchanger (212) or the second heat exchanger (214), and wherein the heat pump unit is arranged above the first pump (208) and the second pump (210); and Activating at least one heat pump stage (200) in the operating position,

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