HEAT PUMP WITH MOTOR COOLING

Description

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

[0002] Fig. 8A und Fig. 8B These components represent 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. 8A The turbomachine is designated 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, for example 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. 8B The table shows an illustration of different pressures and the evaporation temperatures associated with these pressures, from which it can be seen 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] A general problem with heat pumps is the need to cool moving parts, especially those that move quickly. The compressor motor, and particularly its shaft, poses a significant challenge in this regard. Specifically for heat pumps that use radial impellers as compressors, which are operated at very high speeds to achieve a compact design (for example, at speeds exceeding 50,000 revolutions per minute), shaft temperatures can reach problematic levels, potentially leading to component failure.

[0017] US Patent No. 6,070,421 discloses a cooling system. It comprises a condenser, an evaporator, and a two-stage centrifugal compressor assembly with an electric motor, which is equipped with a cooling system. A condenser inlet is connected to a compressor assembly outlet, while a condenser outlet is connected, via first and second throttle elements, to an evaporator inlet and to the cooling system. The evaporator outlet communicates with the compressor assembly inlet, and the cooling system outlet communicates with the second-stage inlet of the assembly. The cooling system is provided with a cooling skirt that includes a cooling system cavity located between a stator and a housing.The cooling system has a separator tank, a recuperative heat exchanger, and a temperature control valve. This valve is controlled by the coolant pressure and temperature at the cooling jacket inlet and is also installed in series with the separator tank in the line connecting the condenser inlet to the evaporator. The separator tank is connected to the coolant supply line via a gas line. The heat exchanger is connected via the coolant to a line that links the condenser outlet, through the separator tank, to the evaporator inlet. The second throttling element is a temperature-controlled valve, regulated by the pressure and temperature of the coolant in the coolant outlet line from the cooling jacket.

[0018] WO 2014 / 0895551 A1 discloses cooling systems and methods for controlling the temperature of engines in gas compression systems. Certain systems use a two-stage centrifugal compressor equipped with an engine between the stages. The cooling system provides a low-velocity coolant spray to at least one or both ends of the engine without requiring additional pumping energy from the engine to deliver the coolant spray.

[0019] The object of the present invention is to create a safe concept for a heat pump.

[0020] This problem is solved by a heat pump according to claim 1 or a method for manufacturing a heat pump according to claim 14, or a method for operating a heat pump according to claim 15.

[0021] The heat pump according to one example incorporates a special convective wave cooling system. This heat pump has a condenser with a condenser housing, a compressor motor attached to the condenser housing and comprising a rotor and a stator. The rotor has a motor shaft to which a radial wheel is attached, extending into an evaporator zone, and a guide chamber designed to receive vapor compressed by the radial wheel and direct it into the condenser. Furthermore, this heat pump has a motor housing surrounding the compressor motor, preferably designed to maintain a pressure at least equal to the pressure in the condenser. However, a pressure greater than the pressure behind the radial wheel is also sufficient. In certain embodiments, this pressure settles at a level midway between the condenser pressure and the evaporator pressure.Furthermore, a steam supply is provided in the motor housing to supply steam to a motor gap between the stator and the motor shaft. The motor is also designed such that a further gap extends from the motor gap between the stator and the motor shaft along the radial gear to the guide chamber.

[0022] This results in a relatively high pressure within the motor housing, higher than the average pressure from the condenser and evaporator, and preferably equal to or higher than the condenser pressure, while a lower pressure prevails in the further gap extending along the radial wheel to the guide chamber. This pressure, equal to the average pressure from the condenser and evaporator, exists because, during the compression of the vapor from the evaporator, the radial wheel creates a high-pressure area upstream of the wheel and a low-pressure or vacuum area downstream of the wheel. Specifically, the high-pressure area upstream of the radial wheel is still lower than the high pressure in the condenser, and the low pressure, so to speak, "downstream" the radial wheel is even lower than the high pressure at the radial wheel's outlet. Only at the outlet of the guide chamber does the high condenser pressure then exist.

[0023] This pressure differential, coupled to the motor gap, ensures that working steam is drawn from the motor housing, via the steam supply, along the motor gap and the wider gap into the condenser. This steam is at or above the temperature of the condenser's working fluid. This is advantageous because it prevents all condensation problems within the motor, and especially within the motor shaft, which would otherwise promote corrosion.

[0024] In this example, the coldest working fluid, namely that present in the evaporator, is not used for convective shaft cooling. Nor is the cold vapor in the evaporator used. Instead, the vapor at condenser or condenser temperature, which is present in the heat pump, is used for convective shaft cooling. This still achieves sufficient shaft cooling due to its convective nature; that is, the motor shaft is surrounded by a significant and, in particular, adjustable amount of vapor due to the vapor supply, the motor gap, and the additional gap. At the same time, because this vapor is relatively warm compared to the vapor in the evaporator, it is ensured that no condensation occurs along the motor shaft in the motor gap or the additional gap. Instead, a temperature is always maintained that is higher than the coldest temperature.Condensation always occurs at the coldest temperature in a volume, and therefore not within the motor gap and the wider gap, since these are surrounded by the warm steam.

[0025] This example demonstrates sufficient convective shaft cooling. This prevents excessively high temperatures in the motor shaft and the associated wear. Furthermore, it effectively prevents condensation from occurring in the motor, for example, when the heat pump is not running. This also effectively eliminates all operational safety and corrosion problems that would be associated with such condensation. The example based on convective shaft cooling results in a significantly more reliable heat pump.

[0026] In the present invention, which relates to a heat pump with motor cooling, the heat pump comprises a condenser with a condenser housing, a compressor motor mounted on the condenser housing and having a rotor and a stator. The rotor includes a motor shaft to which a compressor wheel for compressing working fluid vapor is attached. The compressor motor also has a motor wall. The heat pump includes a motor housing that surrounds the compressor motor and is preferably designed to maintain a pressure at least equal to the pressure in the condenser, and which has a working fluid inlet to supply liquid working fluid from the condenser to the motor wall for motor cooling. However, the pressure in the motor housing can also be lower, since heat dissipation from the motor housing occurs through boiling or evaporation.The heat energy at the engine wall is thus primarily carried away by the steam, which is then discharged, for example, into the condenser. Alternatively, the steam from the engine cooling system can also be directed into the evaporator or to the outside. However, directing the heated steam into the condenser is preferred. In contrast to water cooling, where an engine is cooled by flowing water, cooling in the invention occurs through evaporation, so that the heat energy to be removed is carried away by the provided steam discharge. One advantage is that less liquid is required for cooling and the steam can be easily discharged, e.g., automatically into the condenser, where the steam then condenses again and thus transfers the heat output of the engine to the condenser fluid.

[0027] The motor housing is therefore designed to create a vapor space during the operation of the heat pump, containing the working fluid due to nucleate boiling or evaporation. The motor housing is further designed to discharge the vapor from this vapor space through a vapor outlet. This discharge leads to the condenser, achieved via a gas-permeable connection between the condenser and the motor housing.

[0028] The motor housing is further designed to maintain a maximum level of liquid refrigerant within the housing during heat pump operation and to create a vapor space above this maximum level. The motor housing is also designed to direct any refrigerant above the maximum level into the condenser. This design allows for robust cooling through vapor generation, as the constant level of refrigerant ensures sufficient refrigerant is present on the motor wall for bubble boiling. Alternatively, instead of maintaining a constant level of refrigerant, refrigerant can be sprayed onto the motor wall. The sprayed fluid is metered so that it evaporates upon contact with the motor wall, thereby achieving the cooling effect for the motor.

[0029] The engine is thus effectively cooled at its housing by liquid refrigerant. This liquid refrigerant is not the cold refrigerant from the evaporator, but the warm refrigerant from the condenser. Using the warm refrigerant from the condenser still provides sufficient engine cooling. At the same time, it is ensured that the engine is not cooled too much, and in particular, that it is not cooled to the point where it is the coldest part in the condenser or on the condenser housing. This would lead to condensation of refrigerant vapor on the outside of the engine housing, both when the engine is off and during operation, which would cause corrosion and other problems.Instead, it is ensured that the motor is well cooled, but at the same time is always the warmest part of the heat pump, so that condensation, which always takes place at the coldest "end", does not occur on the compressor motor.

[0030] Preferably, the liquid working fluid in the motor housing is maintained at nearly the same pressure as the condenser. This results in the working fluid cooling the motor being close to its boiling point, since this working fluid is the condenser fluid and is at a similar temperature to that in the condenser. If the motor wall is now heated due to friction from motor operation, the thermal energy is transferred to the liquid working fluid. Because the liquid working fluid is close to its boiling point, bubble boiling begins in the liquid working fluid that fills the motor housing to its maximum level.

[0031] This bubble boiling enables exceptionally efficient cooling due to the very thorough mixing of the liquid working fluid within the motor housing. This boiling-assisted cooling can be further enhanced by a preferably integrated convection element, resulting in highly efficient motor cooling with a relatively small volume, or even no, of stagnant liquid working fluid. Moreover, this self-regulating cooling requires no further control. Thus, efficient motor cooling is achieved with minimal technical effort, which in turn significantly contributes to the operational reliability of the heat pump.

[0032] Preferred embodiments of the present invention are explained in detail below with reference to the accompanying drawings. These show: Fig. 1 a schematic view of a heat pump with an interlocked evaporator / condenser arrangement; Fig. 2 a schematic representation of a heat pump with convective wave cooling according to one aspect; Fig. 3 a schematic representation of a heat pump with convective wave cooling on the one hand and motor cooling according to another aspect; Fig. 4 a sectional view of a heat pump according to an embodiment with convective wave cooling on the one hand and motor cooling on the other, with special consideration of the convective wave cooling; Fig. 5 a sectional view of a heat pump with an evaporator plate and a condenser plate according to the embodiment of Fig. 1 Fig. 6 a perspective view of a condenser as shown in WO 2014072239 A1; Fig. 7 a view of the liquid distribution plate on the one hand and the vapor inlet zone with vapor inlet gap on the other hand from WO 2014072239 A1; Fig. 8a a schematic representation of a known heat pump for evaporating water; Fig. 8 a table illustrating pressures and evaporation temperatures of water as the working fluid; Fig. 9 a schematic representation of a heat pump with motor cooling according to the second aspect; Fig. 10 a heat pump according to an embodiment with convective shaft cooling according to the first aspect and motor cooling according to the second aspect, with particular emphasis on motor cooling; and Fig. 11 a cross-section through a motor shaft with a bearing section according to embodiments of the present invention.

[0033] Fig. 1 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. 1 As shown in the figure, 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 which is not described in detail, but is in principle designed 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 pressure of the evaporator. Fig. 1 In the illustrated embodiment, the capacitor compartment is completely surrounded by the capacitor space wall 114. This means that the capacitor compartment, as shown in Fig. 1 shown, extends to the evaporator base, and that the evaporator chamber simultaneously extends very far upwards, typically through almost the entire condenser chamber 104.

[0034] 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. For example, in a cylindrical form, the heat pump 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.

[0035] Furthermore, it should be noted that the operating direction of the heat pump is as shown in Fig. 1 This is shown. This means that, during operation, the evaporator base defines the lower section of the heat pump, 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.

[0036] 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.

[0037] 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.

[0038] 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 openings for sensors in 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 opening 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.

[0039] 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.

[0040] 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, ensure that the corresponding pipes / lines can be kept as short as possible, contributing to a compact overall design of the heat pump.

[0041] In 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.

[0042] 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.

[0043] 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 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.

[0044] In the present application, identical reference numerals refer to identical or equivalent elements, and not all reference numerals are repeated in all drawings.

[0045] Fig. 2 The image shows a heat pump according to an exemplary embodiment in conjunction with the first aspect, convective wave cooling. Thus, the heat pump comprises Fig. 2 a condenser with a condenser housing 114, which includes a condenser chamber 104. Furthermore, the compressor motor is attached, which is schematically represented by the stator 308 in Fig. 4 This compressor motor is shown in Fig. 2 The condenser housing 114 is attached in a manner not shown and comprises the stator and a rotor 306, the rotor 306 having a motor shaft to which a radial wheel 304 is attached, extending into an evaporation zone which is in Fig. 2 not shown. Furthermore, the heat pump includes a guide chamber 302, which is designed to receive steam compressed by the radial wheel and direct it into the condenser, as shown schematically in Figure 112.

[0046] Furthermore, the motor comprises a motor housing 300 that surrounds the compressor motor and is preferably designed to maintain a pressure at least equal to the pressure in the condenser. Alternatively, the motor housing is designed to maintain a pressure higher than the average pressure between the evaporator and the condenser, or higher than the pressure in the wider gap 313 between the radial wheel and the guide chamber (302), or greater than or equal to the pressure in the condenser. The motor housing is thus designed such that a pressure drop occurs from the motor housing along the motor shaft towards the guide chamber, drawing working steam through the motor gap and the wider gap along the motor shaft to cool the shaft.

[0047] This area within the engine casing, with the necessary pressure, is in Fig. 2 Figure 312 shows the motor housing 300. A steam supply 310 is also provided to supply steam to a motor gap 311 located between the stator 308 and the shaft 306 within the motor housing 300. Furthermore, the motor includes another gap 313 extending from the motor gap 311 along the radial wheel to the guide chamber 302.

[0048] In the arrangement according to the invention, a relatively high pressure p3 prevails in the condenser. In contrast, a medium pressure p2 prevails in the guideway or guide chamber 302. The lowest pressure, apart from the evaporator, prevails behind the radial wheel, specifically where the radial wheel is attached to the motor shaft, i.e., in the wider gap 313. A pressure p4 exists in the motor housing 300, which is either equal to or greater than the pressure p3. This creates a pressure gradient from the motor housing to the end of the wider gap. This pressure gradient causes a steam flow through the steam supply into the motor gap and the wider gap up to the guideway 302. This steam flow carries working steam from the motor housing past the motor shaft into the condenser. This steam flow provides convective shaft cooling of the motor shaft through the motor gap 311 and the wider gap 313, which adjoins the motor gap 311.The radial wheel draws steam downwards, past the motor shaft. This steam is then drawn into the motor gap via the steam inlet, which is typically implemented as specially designed bores.

[0049] Fig. 3 shows a further schematic embodiment of the convective wave cooling according to the first aspect of the present invention, which is preferably combined there with the motor cooling according to the second aspect of the present invention.

[0050] However, it should be noted at this point that the two aspects, convective shaft cooling on the one hand and motor cooling on the other, can also be used separately. Motor cooling without a separate convective shaft cooling system already leads to significantly increased operational reliability. Furthermore, convective motor shaft cooling without additional motor cooling also leads to increased operational reliability of the heat pump. However, as will be explained below... Fig. 3 As shown, they can be connected particularly favorably in order to implement both convective shaft cooling and motor cooling with a particularly advantageous design of the motor housing and the compressor motor, which in a further preferred embodiment can be supplemented individually or jointly by special ball bearing cooling.

[0051] Fig. 3 shows an embodiment with combined use of convective shaft cooling and motor cooling, wherein in the Fig. 3 In the illustrated embodiment, the evaporator zone is shown at 102. The evaporator zone is separated from the condenser zone, i.e., from the condenser area 104, by the condenser base 106. Working steam, which is schematically shown at 314, is drawn in by the rotating radial wheel 304 (shown schematically and in section) and "forced" into the guideway 302. The guideway 302 is located in the Fig. 3 In the illustrated embodiment, the radial wheel is designed such that its cross-section increases towards the outside. This results in further steam compression. The first stage of steam compression occurs through the rotation of the radial wheel and the drawing in of steam. However, when the radial wheel feeds the steam into the inlet of the guideway, i.e., where the radial wheel "ends" at the top, the already pre-compressed steam encounters a kind of steam build-up caused by the narrowing and curvature of the guideway. This leads to further steam compression, so that finally the compressed and thus heated steam 112 flows into the condenser.

[0052] Fig. 3 further shows the steam supply openings 320, which are shown in a schematically depicted engine wall 309 in Fig. 3 are executed. This engine wall 309 has in the Fig. 3 In the illustrated embodiment, bores for the steam supply openings 320 are located in the upper area. However, these bores can be situated at any point where steam can penetrate into the motor gap 311 and thus also into the further motor gap 313. The resulting steam flow 310 leads to the desired effect of convective shaft cooling.

[0053] The in Fig. 3 The illustrated embodiment further includes, for the implementation of motor cooling, a working fluid inlet 330, which is designed to direct liquid working fluid from the condenser to the motor wall for motor cooling. Furthermore, the motor housing is designed to maintain a maximum liquid level 322 of liquid working fluid during operation of the heat pump. In addition, the motor housing 300 is also designed to form a vapor space 323 above the maximum level. The motor housing also has provisions to direct liquid working fluid above the maximum level into the condenser 104. This embodiment is used in the [reference to be added] Fig. 3 In the illustrated embodiment, the overflow is formed by, for example, a flat, channel-shaped overflow 324, which serves as the vapor outlet and is located somewhere in the upper condenser wall and has a length that defines the maximum level 322. If too much working fluid is introduced into the motor housing, i.e., the fluid area 328, through the condenser fluid supply 330, the liquid working fluid flows through the overflow 324 into the condenser volume. Furthermore, the overflow also provides a buffer zone in the event of... Fig. 3 The passive arrangement shown, which could alternatively be a tube of a corresponding length, creates a pressure equalization between the motor housing, and in particular the vapor space 323 of the motor housing, and the condenser interior 104. Thus, the pressure in the vapor space 323 of the motor housing is always almost equal to, or at most slightly higher than, the pressure in the condenser due to a pressure loss along the overflow. Therefore, the boiling point of the liquid 328 in the motor housing will be similar to the boiling point in the condenser housing. Consequently, heating of the motor wall 309 due to power loss generated in the motor leads to bubble boiling in the liquid volume 328, which will be explained later.

[0054] Fig. 3 The figure also shows various seals in schematic form at reference numeral 326 and at similar locations between the motor housing and the condenser housing on the one hand, and between the motor wall 309 and the condenser housing 114 on the other. These seals are intended to symbolize that a liquid- and pressure-tight connection is to be established here.

[0055] The motor housing defines a separate space, which, however, represents a pressure zone almost identical to that of the condenser. Due to the heating of the motor and the energy thereby transferred to the motor wall 309, this promotes bubble boiling in the liquid volume 328. This, in turn, results in a particularly efficient distribution of the working fluid within volume 328 and thus particularly effective cooling with a small volume of coolant. Furthermore, it is ensured that cooling is performed with the working fluid at its most favorable temperature, namely the warmest temperature in the heat pump. This ensures that all condensation problems, which always occur on cold surfaces, are eliminated for the motor wall, the motor shaft, and the areas in the motor gap 311 and the further gap 313. Furthermore, in the Fig. 3 In the illustrated embodiment, the working fluid vapor 310 used for convective shaft cooling is vapor that is otherwise located in the vapor space 323 of the motor housing. This vapor, like the liquid 328, also has the optimal (warm) temperature. Furthermore, the overflow 324 ensures that the pressure in area 323 cannot rise above the condenser pressure due to the nucleate boiling caused by the motor cooling or the motor wall 309. Additionally, the vapor discharge dissipates the heat energy generated by the motor cooling. This ensures that the convective shaft cooling always operates consistently. If the pressure were to rise too high, excessive working fluid vapor could be forced through the motor gap 311 and the further gap 313.

[0056] The 320 bores for steam supply are typically formed in an array, which can be arranged regularly or irregularly. The individual bores are no larger than 5 mm in diameter and can have a minimum size of approximately 1 mm.

[0057] Fig. 6 shows a liquefier, where the liquefier is in Fig. 6 a steam inlet zone 102 that extends completely around the condensation zone 100. In particular, in Fig. 6 A portion of a condenser is shown, comprising a condenser base 200. A condenser housing section 202 is arranged on the condenser base, which, as shown in the illustration, Fig. 6 The condenser is depicted as transparent, but in reality it does not necessarily have to be transparent; it could be made of, for example, plastic, die-cast aluminum, or something similar. The side housing part 202 rests on a rubber seal 201 to ensure a good seal with the base 200. Furthermore, the condenser includes a liquid outlet 203, a liquid inlet 204, and a vapor inlet 205 centrally located within the condenser, which extends from bottom to top. Fig. 6 rejuvenated. It should be noted that Fig. 6 The desired installation direction of a heat pump and its condenser is represented, whereby in this installation direction in Fig. 6 The evaporator of a heat pump is located below the condenser. The condensation zone 100 is bounded externally by a basket-like boundary element 207, which, like the outer housing part 202, is shown transparent and is normally basket-shaped.

[0058] Furthermore, a grid 209 is arranged, which is designed to hold filler bodies that are in Fig. 6 not shown, to wear. As it appears from Fig. 6 As can be seen, the basket 207 extends downwards only to a certain point. The basket 207 is designed to be vapor-permeable in order to hold packing materials, such as so-called Pall rings. These packing materials are introduced into the condensation zone, specifically only within the basket 207, but not in the vapor inlet zone 102. However, the packing materials are also filled to a height outside the basket 207, such that their height extends either to the lower boundary of the basket 207 or slightly above it.

[0059] The liquefier of Fig. 6 includes a working fluid supply, which is in particular characterized by the working fluid supply 204, as described in Fig. 6 As shown, the working fluid supply is arranged around the steam supply in the form of an ascending coil, formed by a liquid transport area 210 and by a liquid distribution element 212, which is preferably designed as a perforated plate. In particular, the working fluid supply is thus designed to supply the working fluid to the condensation zone.

[0060] Furthermore, a steam feeder is also provided, which, as described in Fig. 6 The assembly shown preferably consists of the funnel-shaped, tapered feed section 205 and the upper steam guide section 213. A radial compressor wheel is preferably used in the steam guide section 213, and the radial compression causes steam to be drawn from bottom to top through the feed section 205. Due to the radial compression by the radial wheel, the steam is then deflected outwards by approximately 90 degrees, thus changing the flow from bottom to top to center to outwards. Fig. 6 regarding element 213.

[0061] In Fig. 6 Not shown is a further deflector that deflects the already outwardly deflected steam by another 90 degrees in order to then direct it from above into the gap 215, which in a sense represents the beginning of the steam inlet zone that extends laterally around the condensation zone. The steam inlet is therefore preferably annular in shape and provided with an annular gap for supplying the steam to be condensed, with the working fluid supply being located within the annular gap.

[0062] To illustrate, the following is shown: Fig. 7 referred. Fig. 7 shows a view of the "lid area" of the condenser of Fig. 6 from below. In particular, the perforated plate 212, which acts as a liquid distribution element, is shown schematically from below. The vapor inlet gap 215 is drawn schematically, and it follows from Fig. 7 The vapor inlet gap is only annular in shape, such that no vapor to be condensed is fed directly into the condensation zone from above or below, but only laterally. Thus, only liquid flows through the holes of the distributor plate 212, but no vapor. The vapor is only drawn laterally into the condensation zone by the liquid that has passed through the perforated plate 212. The liquid distributor plate can be made of metal, plastic, or a similar material and can be manufactured with different hole patterns. Furthermore, as described in Fig. 6 As shown, preferably a lateral boundary is provided for liquid flowing from element 210, wherein this lateral boundary is designated 217. This ensures that liquid which exits element 210 with a swirl due to the curved feed 204 and is distributed from the inside out on the liquid distributor does not splash over the edge into the steam inlet zone, unless the liquid has already dripped through the holes of the liquid distributor plate and condensed with steam.

[0063] Fig. 5 shows a complete heat pump in cross-sectional view, including both the evaporator base 108 and the condenser base 106. As shown in Fig. 5 or also in Fig. 1 As shown, the condenser base 106 has a tapered cross-section from an inlet for the working fluid to be evaporated to an extraction opening 115, which is coupled to the compressor or motor 110, where the preferably used radial wheel of the motor extracts the vapor generated in the evaporator chamber 102.

[0064] Fig. 5 Figure 1 shows a cross-section through the entire heat pump. In particular, a droplet separator 404 is arranged within the condenser base. This droplet separator comprises individual blades 405. To keep the droplet separator in place, these blades are inserted into corresponding grooves 406, which are located in Fig. 5 These grooves are arranged in the condenser base in an area facing the evaporator base, on the inside of the evaporator base. Furthermore, the condenser base has various guide features, which can be designed as rods or tongues, to hold hoses intended, for example, for condenser water supply. These hoses are attached to corresponding sections and connect to the condenser water supply inlets. This condenser water supply 402 can be configured, depending on the implementation, as shown in the Fig. 6 and 7as shown in reference numerals 102, 207 to 250. Furthermore, the capacitor preferably has a capacitor fluid distribution arrangement with two or more injection points. A first injection point is therefore connected to a first section of a capacitor inlet. A second injection point is connected to a second section of the capacitor inlet. If more injection points are provided for the capacitor fluid distribution arrangement, the capacitor inlet will be divided into further sections.

[0065] The upper part of the heat pump of Fig. 5 can therefore be used in the same way as the upper area in Fig. 6 be designed in such a way that the condenser water supply is via the perforated sheet of Fig. 6 and Fig. 7 This occurs so that downward-flowing condenser water 408 is obtained, into which the working steam 112 is preferably introduced laterally, so that cross-flow condensation, which allows for particularly high efficiency, can be obtained. As is also the case in Fig. 6 As shown, the condensation zone can be provided with a merely optional filling, in which the edge 207, also designated 409, remains free of packing materials or similar substances, so that the working steam 112 can penetrate the condensation zone not only from above, but also laterally from below. The imaginary boundary line 410 is intended to represent this. Fig. 5 illustrate. In the case of the Fig. 5 In the illustrated embodiment, however, the entire area of ​​the condenser is designed with its own condenser base 200, which is arranged above an evaporator base.

[0066] Fig. 4 Figure 1 shows a preferred embodiment of a heat pump and, in particular, of a heat pump section, which comprises the "upper" area of ​​the heat pump, as is the case, for example, in Fig. 5 The illustration shows. In particular, the M 110 engine corresponds to... Fig. 5 the area surrounded by a motor wall 309, which in the cross-sectional view in Fig. 4 The fluid area 328 is preferably designed with cooling fins on the outside to increase the surface area of ​​the motor wall 309. Furthermore, the area of ​​the motor housing 300 corresponds to Fig. 4 the corresponding area 300 in Fig. 5 In Fig. 4 Furthermore, the radial gear 304 is shown in a more detailed cross-section. The radial gear 304 is mounted on the motor shaft 306 in a fork-shaped mounting area. The motor shaft 306 has a rotor 307, which is opposite the stator 308. The rotor 307 schematically comprises Fig. 4 The permanent magnets shown are depicted. In particular, the steam path 310 through the motor gap 311 is shown. The motor gap 311 extends between the rotor and the stator and opens into the further gap 313, which runs along the forked cross-section mounting area of ​​the shaft 306 to the guide space 302, as also shown in 346.

[0067] Furthermore, in Fig. 4 An emergency bearing 344 is shown, which does not support the shaft during normal operation. Instead, the shaft is supported by the bearing section shown at 343. The emergency bearing 344 is only present to support the shaft and thus the radial wheel in the event of damage, so that the rapidly rotating radial wheel cannot cause further damage to the heat pump. Fig. 4 It also shows various fasteners, such as screws, nuts, etc., and various seals in the form of different O-rings. Furthermore, it shows Fig. 4 an additional convection element 342, which will be referred to later Fig. 10 will be addressed.

[0068] Fig. 4 Figure 360 ​​further shows a splash guard 360 in the vapor space above the maximum volume in the motor housing, which is normally filled with liquid working fluid. This splash guard is designed to catch liquid droplets flung into the vapor space during nucleate boiling. Preferably, the vapor path 310 is shown schematically in Figure 360. Fig. 4 It is indicated that it is designed to benefit from the 360° splash guard, i.e., that due to the flow into the motor gap and the further gap, only working fluid vapor, but not liquid droplets due to boiling in the motor housing, are drawn in.

[0069] The heat pump with convective shaft cooling preferably has a steam supply designed such that a steam flow through the motor gap and the further gap does not pass through a bearing section designed to support the motor shaft relative to the stator. This is in Fig. 4 As indicated. The bearing section 343, which in this case comprises two ball bearings, is sealed from the motor gap, for example by O-rings 351. Thus, the working steam can only escape as seen through the path 310 in Fig. 4 As shown, the steam enters an area within the motor wall 309 via the steam supply, flows downwards in a free space, and along the rotor 307 through the motor gap 311 into the further gap 313. The advantage of this is that the ball bearings are not exposed to steam, thus ensuring that the bearing lubrication remains within the sealed ball bearings and is not drawn through the motor gap. Furthermore, this also ensures that the ball bearing is not moistened, but always remains in the defined state it was in upon installation.

[0070] In another embodiment, the motor housing, as shown in Fig. 4 shown is the heat pump in its operating position, mounted on top of the condenser housing 114, so that the stator is located above the radial wheel and the steam flow 310 passes through the motor gap and the further gap from top to bottom.

[0071] Furthermore, the heat pump includes the bearing section 343, which is designed to support the motor shaft relative to the stator. The bearing section is also arranged such that the rotor 307 and the stator 308 are located between the bearing section and the radial wheel 304. This has the advantage that the bearing section 343 can be located in the steam zone within the motor housing, and the rotor / stator, where the greatest power loss occurs, is located below the maximum liquid level 322 ( Fig. 3 ) can be arranged. This creates an optimal arrangement whereby each area is in the medium best suited to its purpose, namely motor cooling on the one hand, convective shaft cooling on the other, and, if applicable, ball bearing cooling, which will be discussed further below. Fig. 10 will be addressed.

[0072] The motor housing also includes the working fluid inlet 330 to direct liquid working fluid from the condenser to a wall of the compressor motor for motor cooling. Fig. 10 shows a special implementation of this work equipment inlet 362, which corresponds to the inlet 330 of Fig. 3 This corresponds to the working fluid inlet 362 leading into a closed volume 364, which represents a ball bearing cooling system. A discharge emerges from the ball bearing cooling system, comprising a tube 366 that prevents the working fluid from being directed onto the top of the working fluid volume 328, as in Fig. 3 The tube 366 is designed to be located within the convection element 342, which is arranged around the motor wall 309, at a certain distance, so that a volume of liquid working fluid exists both inside and outside the convection element 342 within the motor housing 300.

[0073] A convection zone 367 is created within the volume of working fluid 328 by the nucleate boiling of the working fluid, which is in contact with the motor wall 309, particularly in the lower area where the fresh working fluid inlet 366 terminates. Specifically, the boiling bubbles are drawn upwards by the nucleate boiling process. This results in a continuous "stirring" of hot working fluid from the bottom to the top. The energy from the nucleate boiling is then transferred to the vapor bubble, which ends up in the vapor volume 323 above the liquid volume 328. The resulting pressure is immediately transferred to the condenser via the overflow 324, the overflow extension 340, and the outlet 342. This results in a continuous heat transfer from the motor to the condenser, primarily due to the discharge of vapor and not the discharge of heated liquid.

[0074] This means that the heat, which is actually waste heat from the engine, is preferentially transferred via the steam extraction system to exactly where it's needed: the condenser water to be heated. This keeps all the engine heat within the system, which is particularly advantageous for heating applications of the heat pump. However, heat transfer from the engine to the condenser is also beneficial for cooling applications of the heat pump, because the condenser is typically coupled with an efficient heat dissipation system, such as a heat exchanger or direct heat dissipation in the area to be heated. Therefore, a separate engine heat recovery system isn't necessary; instead, the existing heat dissipation from the condenser to the outside, already used by the heat pump, is essentially "utilized" by the engine cooling system.

[0075] The motor housing is further designed to maintain the maximum level of liquid working fluid during operation of the heat pump and to create the steam space 323 above the liquid working fluid level. The steam supply is further designed to communicate with the steam space, so that the steam in the steam space is used for convective wave cooling through the motor gap and the further gap in Fig. 4 is being managed.

[0076] At the in Fig. 10 and Fig. 4 In the heat pump shown, the drain is arranged as an overflow in the motor housing to direct liquid working fluid above the level into the condenser and to furthermore to create a vapor path between the vapor space and the condenser. Preferably, the drain 324 is both an overflow and a vapor path. However, these functionalities can also be implemented by an alternative design of the overflow on the one hand and a vapor space on the other, using different elements.

[0077] The heat pump includes, in the Fig. 10 The illustrated embodiment features a special ball bearing cooling system, characterized in particular by the fact that a sealed volume 364 containing liquid working fluid surrounds the bearing section 343. The inlet 362 enters this volume, and the volume has an outlet 366 from the ball bearing cooling system into the working fluid volume for motor cooling. This creates a separate ball bearing cooling system that, however, runs around the outside of the ball bearing and not inside it. Thus, while this ball bearing cooling system provides efficient cooling, it does not impair the lubrication of the bearing.

[0078] As further explained in Fig. 10 As shown, the working fluid inlet 362 includes in particular the line section 366, which extends almost to the bottom of the motor housing 300 or to the bottom of the liquid working fluid 328 in the motor housing or at least to a region below the maximum level, in order in particular to carry liquid working fluid out of the ball bearing cooling and to supply the liquid working fluid to the motor wall.

[0079] Fig. 10 and Fig. 4 They further show the convection element, which is arranged in the liquid working fluid at a distance from the wall of the compressor motor 309, and which is more permeable to the liquid working fluid in a lower region than in an upper region. In particular, in the Fig. 10 In the illustrated embodiment, the upper region is impermeable and the lower region is relatively highly permeable, and the convection element is designed in the form of a "crown" which is inverted and placed within the liquid volume. This allows the convection zone 367 to be formed as shown in Fig. 10 as shown. However, alternative convection elements 342 can be used which are in some way less permeable at the top than at the bottom. For example, a convection element could be taken which has holes at the bottom that, in shape or number, have a larger cross-sectional area than holes in the upper region. Alternative elements for generating the convection flow 367, as shown in Fig. 10 The ones shown are also usable.

[0080] To protect the motor in the event of a bearing problem, the emergency bearing 344 is provided, which is designed to secure the motor shaft 306 between the rotor 370 and the radial wheel 304. In particular, the further gap 313 extends through a bearing gap of the emergency bearing or preferably through bores intentionally provided in the emergency bearing. In one implementation, the emergency bearing is provided with a plurality of bores so that the emergency bearing itself presents the lowest possible flow resistance to the steam flow 10 for the purposes of convective shaft cooling.

[0081] Fig. 11 Figure 1 shows a schematic cross-section through a motor shaft 306, as it can be used for preferred embodiments. The motor shaft 306 comprises a hatched core, as shown in Figure 2. Fig. 11 The figure shows a rotor, which in its upper section, representing bearing section 343, is supported by preferably two ball bearings 398 and 399. Further down the shaft 306, the rotor is formed with permanent magnets 307. These permanent magnets are mounted on the motor shaft 306 and are held at the top and bottom by stabilizing bands 397, which are preferably made of carbon. The permanent magnets are further held by a stabilizing sleeve 396, which is also preferably made of carbon. This retaining or stabilizing sleeve ensures that the permanent magnets remain securely on the shaft 306 and cannot detach from the shaft due to the very strong centrifugal forces resulting from the high rotational speed of the shaft.

[0082] Preferably, the shaft is made of aluminum and has a fork-shaped mounting section 395, which serves as a holder for the radial gear 304 when the radial gear 304 and the motor shaft are not formed in one piece, but as two separate elements. If the radial gear 304 and the motor shaft 306 are formed in one piece, the gear mounting section 395 is not present; instead, the radial gear 304 connects directly to the motor shaft. As can be seen from the figure, the area of ​​the gear mounting section 395 also contains a... Fig. 10 As can be seen, the emergency storage unit 344 is preferably also made of metal and in particular aluminium.

[0083] The following are specific preferred embodiments of the second aspect regarding engine cooling based on… Fig. 10 shown. In particular, the motor housing 300, which is also in Fig. 3 The motor housing 300 is designed to maintain a pressure that is at most 20% greater than the pressure in the condenser housing during operation of the heat pump. Furthermore, the motor housing 300 can be designed to maintain a pressure so low that, when the motor wall 309 heats up due to motor operation, bubble boiling occurs in the liquid working fluid 328 and in the motor housing 300.

[0084] Preferably, the bearing section 343 is arranged above the maximum fluid level, so that even in the event of a leak in the motor wall 309, no liquid working fluid can enter the bearing section. In contrast, the area of ​​the motor that at least partially comprises the rotor and the stator is located below the maximum level, since the greatest power loss typically occurs in the bearing area on the one hand, and also between the rotor and stator on the other, and this loss can be optimally dissipated by convective nucleation.

[0085] As is particularly evident in Fig. 4 As shown, the overflow 324 is designed such that it has a first tube section that projects into the motor housing, and that it further has a second line section 340 that extends from a curved section 317 to an outlet 342, which is furthermore arranged outside an area in which the guide chamber 302 introduces working steam compressed by the compressor wheel 304 into the condenser.

[0086] Fig. 9 Furthermore, a schematic representation of the heat pump for engine cooling is shown. In particular, the working fluid flow 324 is an alternative to Fig. 4 or as shown in Fig. 20. The process need not be passive, but can also be active, controlled, for example, by a pump or other element, which, depending on the level sensing of level 322, draws some working fluid from the motor housing 300. Alternatively, instead of the tubular drain 324, there could be a resealable opening at the bottom of the motor housing 300, in order to allow a controlled quantity of working fluid to drain from the motor housing into the condenser by briefly opening the resealable opening.

[0087] Fig. 9 Figure 391 further shows the area to be heated, or a heat exchanger, from which a condenser inlet 204 leads into the condenser, and from which a condenser outlet 203 emerges. A pump 392 is also provided to drive the circuit of condenser inlet 204 and condenser outlet 203. This pump 392 preferably has a branch to the inlet 362, as shown schematically. This eliminates the need for a separate pump; instead, the existing pump for the condenser outlet also drives a small portion of the condenser outlet into the inlet line 362 and thus into the liquid volume 328.

[0088] Furthermore, it shows Fig. 9 a general representation of the condenser 114, the compressor motor with motor wall 309 and the motor housing 300, as also shown by Fig. 3 has been described.

Claims

1. Heat pump comprising following features: a condenser (104) comprising a condenser housing (114); a compressor motor comprising a rotor (307) and a stator (308), the rotor (307) comprising a motor shaft (306) on which is mounted a compressor wheel (304) for compressing working medium vapor, and the compressor motor comprising a motor wall (309); a motor housing (300) which surrounds the compressor motor and comprises a working medium intake (362, 330) so as to direct liquid working medium (328) out of the condenser (104) to the motor wall (309) for cooling the motor, wherein the motor housing (300) is configured to maintain a maximum level (322) of liquid working medium (328) within the motor housing (300) during operation of the heat pump, wherein the motor housing (300) is further configured to form a vapor space (323) above the maximum level (322) during operation of the heat pump, and wherein the motor housing (300) further comprises a vapor discharge outlet (324) which is configured to discharge vapor from the vapor space (323) within the motor housing (300) into the condenser (104), characterized in that the compressor motor is mounted on the condenser housing (114) and in that the vapor discharge outlet (324) is configured as an overflow (324) protruding into the motor housing (300) and defining the maximum level (322) of liquid working medium (328), the overflow (324) extending from the motor housing (300) into the condenser (104) and the overflow (324) further representing a vapour passage for vapour from the vapour space (323) into the condenser (104), so that the pressures within the motor housing (300) and in the condenser housing (114) are essentially the same.

2. Heat pump according to claim 1, wherein the motor housing (300) is configured to maintain, at a maximum, a pressure which is higher by 20% than the pressure within the condenser housing (114) during operation of the heat pump, wherein the liquid working medium (328) from the condenser (104) is water.

3. Heat pump according to claim 1, wherein the motor housing (300) is configured to maintain a pressure which is so low that upon heating of the motor wall (309) due to operation of the compressor motor, nucleate boiling takes place in the liquid working medium (328) within the motor housing (300) wherein the liquid working medium (328) from the condenser (104) is water.

4. Heat pump according to any one of the preceding claims, wherein the compressor motor further comprises a bearing portion (343) by means of which the rotor (307) is supported in relation to the stator (308), and wherein the compressor motor is arranged within the motor housing (300) such that the bearing portion (343) is located above the maximum level (322) of liquid working medium (328), or wherein the compressor motor is arranged within the motor housing (300) such that an area of the compressor motor which at least partly comprises the rotor (307) and the stator (308) is arranged below the maximum level (322) of liquid working medium (328).

5. Heat pump according to any one of the preceding claims, wherein the motor wall (309) is provided with cooling ribs (315) which are arranged within the motor housing (300) such that at least a part of the cooling ribs is arranged below the maximum level (322) at the liquid working medium (328).

6. Heat pump according to any one of the preceding claims, wherein in the motor housing (300) a convection element (342) is arranged which extends within the liquid working medium (328) and is spaced apart from the wall of the compressor motor and from a wall of the motor housing (300) and is more permeable to the liquid working medium (328) in a lower area than in an upper area.

7. Heat pump according to claim 6, wherein the convection element (342) is crown-shaped, wherein an area of the convection element (342) which comprises crown teeth defines the lower area, and the upper area of the convection element (342) is non-permeable to the liquid working medium (328).

8. Heat pump according to claim 6 or 7, wherein the convection element (342) is configured and arranged such that the upper area extends up to or beyond the maximum level (322) of liquid working medium (328).

9. Heat pump according to any one of the preceding claims, wherein the working medium intake (362, 330) comprises a line portion which is configured to direct the liquid working medium (328) out of a sealed-off volume (364), and wherein the line portion extends through the liquid working medium (328) within the motor housing (300) so as to feed the liquid working medium (328) within the line portion to a base of the motor housing (300).

10. Heat pump according to any one of the preceding claims, wherein the motor shaft (306) comprises following features: a shaft core (306'); a magnet area (307) comprising permanent magnets attached on the shaft core (306'); and a securing sleeve (396) which is arranged around the magnet area (307) to secure the permanent magnets, wherein the compressor motor is mounted within the motor housing (300) such that the magnet area (307) is positioned below the maximum level (322) of liquid working medium (328).

11. Heat pump according to any one of the claims 1 to 10, which further has an evaporator wherein the motor housing (300) is configured to maintain a pressure which is at least equal to a pressure within the evaporator-wherein the liquid working medium (328) is water.

12. Heat pump according to any one of the claims 1 to 11, wherein the motor housing (300) is further configured to direct the liquid working medium (328) above the maximum level (322) of liquid working medium (328) into the condenser (104).

13. Heat pump according to any one of the claims 1 to 12, wherein a motor gap is configured between the rotor (307) and the stator (308), and wherein the motor housing (300) is configured to keep the liquid working medium (328) away from the motor gap.

14. Method of producing a heat pump comprising following features: a condenser (104) comprising a condenser housing (114); a compressor motor mounted on the condenser housing (114) and comprising a rotor (307) and a stator (308), the rotor (307) comprising a motor shaft (306) on which a compressor wheel (304) is mounted for compressing working medium vapor, and the compressor motor comprising a motor wall (309); a motor housing (300) which surrounds the compressor motor and comprises a working medium intake (362, 330) so as to direct liquid working medium (328) out of the condenser (104) to the motor wall (309) for cooing the motor, the method comprising following steps: configuring the motor housing (300) such that it maintains a maximum level (322) of liquid working medium (328) within the motor housing (300) during operation of the heat pump and that it forms a vapor space (323) above the maximum level (322) of liquid working medium (328) during operation of the heat pump; and arranging a vapor discharge outlet (324) within the motor housing (300) wherein the vapor discharge outlet (324) is configured for discharging vapor from the vapor space (323) within the motor housing (300) into the condenser (104) wherein the vapour discharge outlet (324) is configured as an overflow (324) protruding into the motor housing (300) and defining the maximum level (322) of liquid working medium (328), the overflow (324) extending from the motor housing (300) into the condenser (104) and the overflow (324) further representing a vapour passage for vapour from the vapour space (323) into the condenser (104), so that the pressures within the motor housing (300) and in the condenser housing (114) are essentially the same.

15. Method of operating a heat pump comprising following features; a condenser (104) comprising a condenser housing (114); a compressor motor mounted on the condenser housing (114) and comprising a rotor (307) and a stator (308), the rotor (307) comprising a motor shaft (306) on which is mounted a compressor wheel (304) for compressing working medium vapor, and the compressor motor comprising a motor wall (309); a motor housing (300) which surrounds the compressor motor and comprises a working medium intake (362, 330) so as to direct liquid working medium (328) out of the condenser (104) to the motor wall (309) for cooling the motor, the motor housing (300) being configured to maintain a maximum level (322) of liquid working medium (328) within the motor housing (300) during operation of the heat pump, an the motor housing (300) being further configured to form a vapor space (323) above the maximum level (322) of liquid working medium (328) during operation of the heat pump, the method comprising following step: during operation of the heat pump, discharging vapor from the vapor space (323) within the motor housing (300) into the condenser (104).