Heat pump with multi-stage compressor and spiral housings

Abstract

A heat pump (100) is described, comprising: an evaporator (10) for evaporating operating liquid so as to obtain operating vapor; a compressor (20) for compressing the operating vapor so as to obtain compressed operating vapor; and a condenser (30) for condensing the compressed operating vapor, wherein the compressor (20) comprises a first compressor stage (70-1) and a second compressor stage (70-2), wherein the first compressor stage (70-1) comprises a first spiral housing (78-1), a first drive motor (80-1), and a first drive shaft (86-1), wherein the second compressor stage (70-2) comprises a second spiral housing (78-2), a second drive motor (80-2), and a second drive shaft (86-2), wherein the first drive shaft (86-1) is separate from the second drive shaft (86-2), and wherein the drive shaft (86-1) is configured to be standing in an operation direction of the heat pump (100). Furthermore, a method for manufacturing such a heat pump (100) and a method for operating such a heat pump (100) are described.

Description

[0001] The present invention concerns a heat pump with a multi-stage compressor and spiral housings, a method for manufacturing such a heat pump, and a method for operating such a heat pump.

[0002] The publication (Tadayoshi et al.: Centrifugal turbo chiller using water as refrigerant and lubricant, The 11th International Conference on Compressors and their System, Journal of Process Mechanical Engineering, published on 1 Jul. 2020, DOI: 10.1177 / 0954408920938197) describes a water refrigerant heat pump system 7′ (cf. FIG. 27) with a water vapor turbo compressor, wherein the compressor and the spiral housing are directly and firmly connected to the evaporator and compressor tanks. The water refrigerant heat pump system comprises standing spiral housings with a recumbent shaft, wherein the spiral housings are arranged above the evaporator and the condenser. Both rotor discs are arranged on a drive shaft 5′ and can therefore not be driven separately. The evaporator and the condenser are arranged side by side. The intercooler is located above the evaporator. FIG. 28 shows—as described in the publication—water vapor being sprayed through nozzles. To this end, the water refrigerant heat pump system is elaborately manufactured with vapor nozzles and is made of several chambers (chamber 1′, chamber 2′, chamber 3′) of the intercooler, wherein there is no separation of the intercooler of its storage tank 4′.

[0003] Since both rotor discs are arranged on a recumbent drive shaft, the rotor discs cannot be controlled separately. The equipment can therefore only be operated with two stages. A single-stage operation without the second rotor disc is not possible. In addition, due to the spiral housings standing above the evaporator and the condenser, the water refrigerant heat pump system has a structural height that is quite high. Due to the fact that the evaporator and the condenser are arranged side by side, the water refrigerant heat pump system further has a structural width that is quite large. Overall, the installation space is not utilized well.

[0004] WO 2013 085 969 A1 discloses a refrigerator that uses a centrifugal compressor whose rotor discs are mounted on a shaft that is rotatably mounted by using rolling bearings. FIG. 29 shows the refrigerator, which is a centrifugal refrigerator, and its fundamental components. The refrigerator 10′ consists of a compressor part 12′, a condenser 14′ and an evaporator 16′. The refrigerant gas is compressed in the compressor part 12′. This refrigerant gas is led out of the output spiral 18′ into the pipeline 20′ connecting the compressor and the condenser 14′. The refrigerator of WO 2013 085 969 A1 comprises a standing spiral housing and consequently a recumbent shaft, wherein the spiral housing is arranged above the evaporator and the condenser. Both rotor discs are located on a drive shaft. Consequently, the rotor discs cannot be controlled separately. Furthermore, the impeller is arranged so as to be standing.

[0005] Since both rotor discs are located on a recumbent drive shaft, the rotor discs cannot be controlled separately. The equipment can therefore only be operated in two stages. A single stage operation without the second rotor disc is not possible. In addition, there is no intercooling. Due to the standing spiral housing compressor, the refrigerator of the publication also has a structural height that is quite high.

[0006] It is the object of the present invention to provide an improved heat pump concept.

[0007] This object is solved by a heat pump according to claim 1, a method for manufacturing a heat pump according to claim 25, or a method for operating a heat pump according to claim 26.

[0008] A core idea of the present invention is to arrange individual components of the heat pump such that the components are arranged more closely in less installation space, and to simultaneously provide each drive motor with its own shaft so that each rotor disc can be driven selectively by the respectively associated drive motor. Through this, the heat pump can operate more efficiently in less installation space.

[0009] According to the proposal, the heat pump includes an evaporator (or vaporizer) for evaporating operating liquid so as to obtain operating vapor; a compressor for compressing the operating vapor so as to obtain compressed operating vapor; and a condenser (or liquefier) for condensing the compressed operating vapor, wherein the compressor comprises a first compressor stage and a second compressor stage. The first compressor stage comprises a first spiral housing, a first drive motor, and a first drive shaft. The second compressor stage comprises a second spiral housing, a second drive motor, and a second drive shaft. According to the proposal, the first drive shaft is separated from the second drive shaft, and the first drive shaft is configured so as to be standing in an operation direction of the heat pump. In particular, the second drive shaft is configured so as to be recumbent (or horizontal or reclined) or standing in an operation direction of the heat pump. Preferably, configured to be standing refers to a direction that is vertical to a bottom region of the heat pump, whereas configured to be recumbent refers to a direction that is horizontal to the bottom region of the heat pump. Thus, according to the proposal, each drive motor of the heat pump has its own drive shaft so that each drive motor can be driven independently of the other drive motor. Due to the drive shafts being configured so as to be recumbent or standing, the individual components of the heat pump may be arranged more closely with respect to each other, that is in less installation space, which is why the heat pump itself spans less volume, i.e. it gets smaller.

[0010] A further aspect of the present invention concerns a method for operating the above-described heat pump, and a method for manufacturing the above-described heat pump.

[0011] The method for manufacturing a heat pump with an evaporator for evaporating operating liquid so as to obtain operating vapor; a compressor for compressing the operating vapor so as to obtain compressed operating vapor, and a condenser for condensing the compressed operating vapor, wherein the compressor comprises a first compressor stage and a second compressor stage, wherein the first compressor stage comprises a first spiral housing, a first drive motor, and a first drive shaft, wherein the second compressor stage comprises a second spiral housing, a second drive motor, and a second drive shaft, the method including: arranging the drive shafts so that the first drive shaft is separate from the second drive shaft, and configuring the first drive shaft so as to be standing in an operation direction of the heat pump.

[0012] A method for operating a heat pump with an evaporator for evaporating operating liquid so as to obtain operating vapor; a compressor for compressing the operating vapor so as to obtain compressed operating vapor, and a condenser for condensing the compressed operating vapor, wherein the compressor comprises a first compressor stage and a second compressor stage, wherein the first compressor stage comprises a first spiral housing, a first drive motor, and a first drive shaft, wherein the second compressor stage comprises a second spiral housing, a second drive motor, and a second drive shaft, wherein the first drive shaft is separate from the second drive shaft, the method including: setting up the heat pump in an operation direction; and operating the heat pump in the operation direction so that the first drive shaft is configured to be standing in the operation direction of the heat pump.

[0013] The inventive heat pump concept is advantageous in that it better utilizes the installation space of the heat pump, wherein the heat pump is further configured to be smaller. Due to the inventive heat pump concept, the heat pump can be used efficiently since the components of the heat pump are at least partially manufactured so as to be smaller or shorter by utilizing the installation space.

[0014] It is understood that individual aspects described with reference to the heat pump may also be implemented as a method step and vice versa. Further details are described in the context of the subsequent description of the drawings.

[0015] Preferred embodiments of the present invention are subsequently described in detail with reference to the accompanying drawings, in which:

[0016] FIG. 1 shows a perspective view of the inventive heat pump;

[0017] FIG. 2 shows a side view of the inventive heat pump;

[0018] FIG. 3 shows a front view of the inventive heat pump;

[0019] FIG. 4 shows a hydraulics scheme of the inventive heat pump;

[0020] FIG. 5 shows a perspective view of a further embodiment of the inventive heat pump;

[0021] FIG. 6 shows a side view of the further embodiment of the inventive heat pump;

[0022] FIG. 7 shows a perspective view of an embodiment of the inventive heat pump, wherein the intake funnel is arranged outside of the evaporator;

[0023] FIG. 8 shows a section of the inventive heat pump with a cylindrical configuration of the intercooler;

[0024] FIG. 9 shows an arrangement of the output of the first compressor so as to be off-center at the intercooler in an embodiment of the inventive heat pump;

[0025] FIG. 10 shows an arrangement of the intercooler in the inventive heat pump;

[0026] FIG. 11 shows an arrangement of the intercooler in the inventive heat pump;

[0027] FIG. 12 shows a view of water pipes in the intercooler;

[0028] FIG. 13 shows a cutting ring fitting;

[0029] FIG. 14 shows a further view of water pipes in the intercooler;

[0030] FIG. 15 shows a view of a coiled cooling pipe in the intercooler;

[0031] FIG. 16 shows a connection between the exit pipes of the first and second compressor stages of the inventive heat pump;

[0032] FIG. 17 shows an arrangement of the bypass pipe in the inventive heat pump;

[0033] FIG. 18 shows an arrangement of the intercooler and the intercooling storage tank (cf. FIG. 7) in the inventive heat pump;

[0034] FIG. 19 indicates a droplet separator in front of the second compressor in the inventive heat pump;

[0035] FIGS. 20a-d show a schematic design of a spiral housing;

[0036] FIG. 21 shows a schematic design of a plate of the spiral housing;

[0037] FIG. 22 shows a schematic design of an evolute of the spiral housing;

[0038] FIG. 23 shows views of the spiral housing;

[0039] FIG. 24 shows further views of the spiral housing;

[0040] FIG. 25 shows a flow chart of the method for manufacturing the inventive heat pump;

[0041] FIG. 26 shows a flow chart of the method for operating the inventive heat pump;

[0042] FIG. 27 shows a water refrigerant heat pump system of the prior art;

[0043] FIG. 28 schematically shows the water vapor being sprayed through nozzles known from the prior art; and

[0044] FIG. 29 shows a refrigerator known from the prior art.

[0045] Individual aspects of the invention described herein are subsequently described in FIGS. 1 to 26. In the present application, the same reference numerals concern the same elements or elements having the same effect, wherein not all reference numerals have to be indicated in all drawings in case of repetition. FIGS. 27 to 29 show a heat pump known from the prior art and were already described in the introductory part.

[0046] FIG. 1 shows a perspective view of the inventive heat pump 100, FIG. 2 shows a side view of the inventive heat pump 100, and FIG. 3 shows a front view of the inventive heat pump 100. The heat pump 100 according to a first embodiment is shown when combining FIGS. 1 to 3. The heat pump 100 according to a second embodiment is shown when combining FIGS. 5 and 6.

[0047] The proposed heat pump 100 according to the embodiments described herein includes: an evaporator 10 for evaporating operating liquid so as to obtain operating vapor; a compressor 20 for compressing the operating vapor so as to obtain compressed operating vapor; and a condenser 30 for condensing the compressed operating vapor. According to the proposal, the compressor 20 comprises a first compressor stage 70-1 and a second compressor stage 70-2, wherein the first compressor stage 70-1 comprises a first spiral housing 78-1, a first drive motor 80-1, and a first drive shaft 86-1, wherein the second compressor stage 70-2 comprises a second spiral housing 78-2, a second drive motor 80-2, and a second drive shaft 86-2. According to the proposal, the first drive shaft 86-1 is separate from the second drive shaft 86-2, wherein the first drive shaft 86-1 is configured so as to be standing in an operation direction of the heat pump 100. In this case, the operation direction refers to the direction along which the operating liquid is evaporated, compressed and re-condensed. Thus, the operation direction is no invariable direction, but may be different depending on the structural arrangement of the individual components of the heat pump 100. With respect to the first compressor stage 70-1 comprising the first spiral housing 78-1, the first drive motor 80-1, and the first drive shaft 86-1, the first drive shaft 86-1 is configured so as to be standing, i.e. along a z direction, when using the coordinate system drawn in FIGS. 1-3 and 5 and 6. To be standing in the operation direction may refer to, e.g., in parallel or anti-parallel to the z direction. Anti-parallel to the z direction therefore means in the (minus) “−z” direction. As proposed, each of the drive motors 80-1, 80-2 comprises its own drive shaft 86-1, 86-2, wherein one of the drive shafts 86-1, 86-2 is configured so as to be standing, in particular, in parallel to the z direction. The other drive shaft 86-1, 86-2 may also be configured to be standing, in particular in parallel to the z direction (cf. e.g. FIGS. 1 to 3), or recumbent (cf. e.g. 5 and 6), in particular in parallel to the x direction or the y direction or in parallel to an x-y plane. In particular, the drive shafts 86-1, 86-2 extend through their associated drive motors 80-1, 80-2 such that the associated drive motor 80-1, 80-2 drives the corresponding drive shaft 86-1, 86-2 during operation of the drive motor 80-1,80-2.

[0048] FIG. 1 and FIG. 2 show a recumbent arrangement of the first and second spiral housings 78-1, 78-2. Consequently, the impellers according to the heat pump according to FIGS. 1 to 3 are arranged so as to be recumbent. Due to the recumbent arrangement of the first and second spiral housings 78-1, 78-2, the height, in particular along the z direction, of the heat pump 100 may be limited. Furthermore, FIG. 1 and FIG. 2 show a standing arrangement of the drive shafts 86-1, 86-2 of the first and second spiral housings 78-1, 78-2. According to the heat pump 100, as shown in FIGS. 1 to 3, the first compressor stage 70-1 and the second compressor stage 70-2 can be driven separately from each other, in particular controlled separately from each other. In addition, the impellers each run on a different drive shaft 86-1, 86-2. The compressor 20 comprises a compressor tank 21, in particular configured to be cylindrical. At one end, the compressor tank 21 leads to an evaporator tank 11. At an opposite different end, the compressor tank leads to an intake socket 52. In particular, the evaporator tank 11 is configured to be cylindrical. As shown in FIGS. 1 and 2, the compressor tank 21 may be configured perpendicular to the evaporator tank 11, in particular, the compressor tank 21 and the evaporator tank 11 may be configured to be connected to each other or be configured to be formed integrally. The condenser 30 comprises a condenser tank 31. In particular, the condenser tank 31 is configured to be formed cylindrically. As can be further gathered from FIGS. 1 and 2, the evaporator tank 11 and the condenser tank 31 are each configured to be recumbent, wherein a length of the evaporator tank 11 and the condenser tank 31 extends along an x direction. The evaporator tank 11 and the condenser tank 31 are arranged offset from each other so that the evaporator tank 11 and the condenser tank 31 do not overlap along an x direction (FIG. 2) and are arranged so as to partially overlap (along the z direction) (cf. FIG. 3). Furthermore, the evaporator tank 11 and the condenser tank 31 do not overlap along a y direction (cf. FIG. 3). As can be further gathered from FIG. 1, the evaporator tank 11 and the condenser tank 31 are arranged to be offset transversally from each other. In particular, the evaporator tank 11 and the condenser tank 31 do not overlap along the y direction (cf. FIG. 1 or FIG. 3). FIG. 1 shows the transversal arrangement of the evaporator tank 11 and the condenser tank 31 by means of the slope 200 drawn in. FIGS. 1 and 2 further show that the heat pump 100 comprises an intercooler 42 including an intercooling storage tank 44, wherein the intercooling storage tank 44 is configured as a unit with the intercooler 42. In particular, the intercooling storage tank 44 and the intercooler 42 are each configured to be cylindrical.

[0049] Preferably, the evaporator 10 is configured as a recumbent evaporator cylinder 15. The condenser 30 is preferably configured as a recumbent condenser cylinder 35, wherein the recumbent condenser cylinder 35 is arranged obliquely above the recumbent evaporator cylinder 15 in the operation direction of the heat pump 100, wherein, in particular, the evaporator cylinder 15 and the condenser cylinder 35 vertically overlap at least partially, i.e. in the z direction. As can exemplarily be gathered from FIGS. 1 and 2, the recumbent condenser cylinder 35 and the recumbent evaporator cylinder 15 are each arranged in an x-y plane, wherein these x-y planes are spaced apart along the z direction. The recumbent evaporator cylinder 15 and the recumbent condenser cylinder 35 overlap partially along the z direction. To at least partially overlap means that the x-y plane of the recumbent evaporator cylinder 15 and the x-y plane of the recumbent condenser cylinder 35 partially overlap when viewed along the z direction (cf. FIG. 2). When viewed along the y direction (cf. FIG. 1), the evaporator cylinder 15 and the condenser cylinder 35 preferably do not overlap. In the present case, the condenser cylinder 35 is also referred to as condenser tank 31. In the present case, the evaporator cylinder 15 is also referred to as evaporator tank 11.

[0050] FIG. 3 shows a front view of the inventive heat pump 100. FIG. 3 shows the first spiral housing 78-1 being recumbent with a standing first drive shaft 80-1. In addition, the slope 200 is also plotted in FIG. 3 so as to show the offset arrangement between the condenser cylinder 35 or the condenser tank 31 and the evaporator cylinder 15 or the evaporator tank 11, respectively. In the view according to FIG. 3, the first drive motor 80-1 is covered with a burst bucket 90. Preferably, the first drive shaft 86-1 is also covered with the burst bucket 90.

[0051] FIG. 4 shows a hydraulics scheme of the inventive heat pump 100 as it is essentially shown in FIGS. 1 to 3 and 5-6. According to the hydraulics scheme according to FIG. 4, the first and second spiral housings 78 are arranged so as to recumbent, in particular in an x-y plane. The first compressor stage 70-1 is connected to the second compressor stage 70-2 via an intercooler 42. The intercooler 42 has an intercooling space 43 where the compressed operating fluid passes through and which is cooled within the intercooling space 43. The intercooling space 43 comprises an entry 47 into the intercooling space 43 and an exit 46 out of the intercooling space 43 to the second compressor stage 70-2. A bypass pipe 84 extends from the exit 46 out of the intercooling space 43 to the second compressor stage 70-2. If only the first compressor stage 70-1 is to be operated, the compressed operating fluid does not pass the intercooler 42, but a pipe 45 that directly leads to the condenser 30. The intercooler exit pipe 45 comprises a hatch 82 that is closed if the operating fluid is to also pass the second compressor stage 70-2, or that is open if the operating fluid is to be led from the first compressor stage 70-1 directly into the condenser 30. The hatch 82 may be configured to be driven or may be configured as a thermal element. Preferably, the hatch 82 is driven such that it opens as soon as the second compressor stage is operated. The intercooler 42 comprises an intercooling storage tank 44. A bypass pipe, or bypass strand, 85 also comprising a hatch 82 is arranged between the condenser 30 and the evaporator 10. The hatch 82 in the bypass strand85 may be configured to be driven or may be configured as a thermal element as well. Preferably, the hatch 82 in the bypass strand 85 is driven such that it opens as soon as the second compressor stage 70-2 is operated in an idle operation.

[0052] Preferably, the intercooling storage tank 44 of the intercooler 42 is arranged, in particular for reasons of space efficiency, below the condenser sump 36 and above the evaporator sump 16 so that the condensed operating fluid, i.e. the condensed water, is able to flow back due to gravity. The operating fluid flows out of the condenser sump 36 via the intercooling storage tank 44 back to the evaporator sump 16 under the effect of gravity.

[0053] Preferably, the intercooler 42 comprising an intercooling space 43 and an intercooling storage tank 44 is arranged between the first compressor stage 70-1 and the second compressor stage 70-2, wherein the intercooling space 43 is configured integrally with the intercooling storage tank 44, and / or wherein the intercooling space 43 is arranged above the evaporator 10 (cf. FIGS. 1 and 2), or wherein the intercooling storage tank 44 is arranged below the condenser sump 36 configured in the condenser 30 and above the evaporator sump 16 configured in the evaporator 10 (cf. FIG. 4). As is shown in FIG. 4, the intercooling storage tank 44 is arranged separately from the intercooler 42. Depending on the available installation space, the arrangement of the intercooler 42 with its intercooling storage tank 44 may be configured integrally or separately.

[0054] FIG. 5 shows a respective view of a further embodiment of the inventive heat pump 100 and FIG. 6 shows a side view of the further embodiment of the inventive heat pump 100. As can be gathered from FIGS. 5 and 6, the second drive shaft 86-2 is preferably arranged so as to be recumbent in the operation direction of the heat pump 100, wherein the first spiral housing 78-1 is arranged so as to be recumbent and the second spiral housing 78-2 is arranged so as to be standing (cf. FIGS. 5 and 6). Under consideration of the coordinate system, this means that the second drive shaft 86-2 and the first spiral housing 78-1 arranged so as to be recumbent extend along the x direction, whereas the second spiral housing 78-2 arranged so as to be standing and the first drive shaft 86-1 extend along the z direction. The first spiral housing 78-1 and the second spiral housing 78-2 are connected via the intercooler 42 (cf. FIG. 4 as well as FIGS. 1 and 2). According to the heat pump 100 according to FIGS. 5 and 6, the first spiral housing 78-1 and the second spiral housing 78-2 are connected via the intercooler 42, whereas, in the heat pump 100 according to FIGS. 1 and 2, the first spiral housing 78-1 and the second spiral housing 78-2 are connected via the intercooler 42 and a bypass pipe 84. Preferably, a further droplet separator 55 is arranged in the bypass pipe 84.

[0055] Preferably, the intercooling space 43 is arranged above the condenser 30 (cf. FIGS. 1, 2, 5 and 6) or is arranged so as to at least partially the condenser 30 (cf. FIGS. 1, 2, 5 and 6) vertically, in particularly along the z direction. Furthermore, the intercooling space 43 is preferably arranged between the first spiral housing 78-1 and the spiral housing 78-2 (cf. FIGS. 1, 2, 5, and 6). Alternatively or additionally, the intercooling storage tank 44 is arranged separately from the intercooling space 43 below the condenser 30 (cf. FIGS. 5 and 6), or an essentially straight or essentially U-shaped bypass pipe 85 is arranged between the condenser 30 and the evaporator 10 in a region in which the condenser 30 and the evaporator 10 at least partially overlap vertically in the operation direction of the heat pump 100 (cf. FIGS. 1 and 2). The bypass pipe 84 is preferably bent, which is why the operation direction of the operating fluid adopts a direction that is different with respect to the coordinate system plotted, provided that the evaporated operating fluid passes the bypass pipe 84. When operating the first compressor stage 70-1 only, the operating fluid may be led directly to the condenser 30 by having the operating fluid pass the pipe connection 45 (cf. FIG. 4 in addition to FIGS. 1, 2, 5, and 6).

[0056] As can be gathered from FIGS. 5 and 6, the first compressor housing 78-1 is recumbent, whereas the second compressor housing 78-2 is standing. Only the intercooler 42 is arranged between the first and second compressor housings 78-1, 78-2. Through this, the flow control of the vapor, i.e. the compressed operating fluid, can be improved since the flow control between the first and the second compressor stage 70-1, 70-2 can be carried out without any further pipes arranged therebetween. In addition, it can be gathered from FIGS. 5 and 6 that a bypass strand 85 is arranged from the condenser 30 to the evaporator 10. The bypass strand 85 enables directly guiding the operating fluid out of the condenser sump 36 into the evaporator sump 16. Furthermore, the heat pump 100 according to FIGS. 5 and 6 comprises a separate intercooling storage tank 44 that is arranged separately from the intercooler 42. The intercooling storage tank 44 is connected to the intercooler 42 for receiving operating fluid from the intercooler 42 (cf. FIG. 4).

[0057] A comparison of FIG. 2 and FIG. 6 shows, according to FIG. 2, that the first and the second spiral housing 78-1, 78-1 are each arranged so as to be recumbent, whereas, according to FIG. 6, the first spiral housing 78-1 is arranged to be standing and the second spiral housing 78-2 is arranged to be recumbent. In both embodiments, i.e. in the heat pump 100 according to FIG. 2 and according to FIG. 6, a stage 1 operation is possible in which only the first compressor stage 70-1 is operated. At the same time. Both embodiments may be operated in a stage 2 operation in which the first and the second compressor stages 70-1, 70-2 are operated. The heat pump 100 according to FIG. 6 comprises an intercooler 42 that is arranged separately from its intercooling storage tank 44. Preferably, the intercooler 42 comprises indirect heat transfer pipes arranged so as to be recumbent, in particular, arranged so as to be wound as a coil in the intercooling space 43. According to the heat pump 100 according to FIG. 2, the intercooler 42 and the intercooling storage tank 44 are configured continuously, in particular cylindrically.

[0058] The heat pump 100 according to FIG. 6 comprises the bypass strand 85 as a direct connection between the condenser 30 and the evaporator 10. The heat pump 100 according to FIG. 2 comprises the bypass strand 85 as a direct connection between the condenser 30 and the evaporator 10, wherein the bypass strand 85 is arranged around the intake socket 52 of the first compressor stage 70-1. Both heat pumps 100 are each arranged in a rack 40.

[0059] Preferably, an intake socket 52 arranged outside of the evaporator 10, as can be seen in FIG. 7 for example, is arranged between the evaporator 10 and the first compressor stage 70-1. Alternatively or additionally, an intake socket 52 arranged outside of the evaporator 10 is arranged between the evaporator 10 and the first compressor stage 70-1, wherein a droplet separator 54 is arranged in the intake socket 52. Furthermore, alternatively or additionally, an intake socket 52 arranged outside of the evaporator 10 and having a length that is at least as large as half of the diameter of the condenser 30 is arranged between the evaporator 10 and the first compressor stage 70-1, and / or wherein the intake socket 52 is arranged so as to be standing, in particular along the z direction. Due to the fact that the droplet separator 54 is arranged in the intake socket 52, the droplet separator 54 can only be implied through its reference numeral. FIG. 7 shows a perspective view of an embodiment of the inventive heat pump, wherein the intake funnel 52 is arranged outside of the evaporator. This simplifies manufacturing and assembly of the inventive heat pump 100. In addition, the evaporator 10, in particular the evaporator tank 11, may be built with a smaller size. Due to the fact that the droplet separator 54 is arranged in the intake socket 52, which is arranged outside of the evaporator 10, arranging and maintaining the droplet separator 54 in the intake socket 52 is simplified. In addition, the danger of a malfunction of the droplet separator 54 may be reduced since the height difference between the water line of the evaporator tank 11 and the entry to the compressor is larger as would be the case if the intake funnel was arranged in the tank so as to arrange the first spiral housing compressor at the height of the second spiral housing compressor. In addition, the evaporator 10, in particular its evaporator tanks 11, may be configured so as to be miniaturized or shortened. By arranging the individual components or modules, particularly the tanks 11, 15, 21, 31, 44, and the spiral housings 78-1, 78-2, of the heat pump 100, installation space may be saved on the one hand, and the flow control of the operating fluid may be improved on the other hand.

[0060] Preferably, an entry 79-1 of the first spiral housing 78-1 arranged so as to be recumbent is arranged in the operation direction of the heat pump 100 on top of the intake socket 52. An exit 77-1 of the first spiral housing 78-1 is connected to an entry 47 of an intercooling space 43 of an intercooler 42. Furthermore, an exit 46 of the intercooling space 43 is preferably connected to an entry 79-2 of the second spiral housing 78-2 arranged so as to be standing, and an exit 77-2 of the second spiral housing 78-2 is connected to an entry 36 of the condenser 30 (cf. FIG. 6), wherein the respective connections are preferably configured to be direct, in particular without any further components therebetween. Alternatively or additionally, the first spiral housing 78-1, the second spiral housing 78-2, and the condenser 30 are arranged so that, during operation of the heat pump 100, a vapor flow is caused through the intake socket 52 in a first direction, a vapor flow is caused through the intercooling space 43 in a second direction essentially perpendicular to the first direction, and a vapor flow is caused from the second spiral housing 78-2 into the condenser 30 in a third direction having at least one directional component that is directed essentially opposite the first direction, and wherein the first spiral housing 78-1 and the second spiral housing 78-2 are arranged and configured to cause a vapor flow directional change of essentially 90 degrees. For example, as can be gathered from FIG. 6 with the help of the coordinate system plotted, the first direction may be parallel to the z direction, whereas the second direction may be parallel to the-x direction. On the other hand, the third direction comprises (x, y, z) coordinates. As can be further gathered from FIGS. 1 and 2, the exit 46 of the intercooling space 43 is connected to the entry 79-2 of the second spiral housing 78-2 via the bypass pipe 84. In the heat pump according to FIGS. 1 and 2 and in the heat pump 100 according to FIGS. 5 and 6, the intercooling space 43 is connected to the condenser 30 via a pipe connection 45.

[0061] Preferably, the first compressor stage 70-1 comprises a first impeller wheel arranged at the first drive shaft 86-1, wherein the second compressor stage 70-2 comprises a second impeller wheel arranged at the second drive shaft 86-2, wherein the first drive shaft 86-1 and the second drive shaft 86-2 are essentially arranged in parallel in the operation direction of the heat pump 100 (cf. FIGS. 1 and 2), wherein the first impeller wheel and the second impeller wheel are arranged essentially at a same height, or wherein, in the operation direction of the heat pump 100, the first drive shaft 86-1 and the second drive shaft 86-2 are essentially arranged perpendicular to each other and the first impeller wheel has a length and the second impeller wheel has a diameter, wherein the first impeller wheel and the second impeller wheel are arranged such that the length of the first impeller wheel and the diameter of the second impeller wheel at least partially overlap. In particular, the length of the first impeller wheel and the diameter of the second impeller wheel essentially overlap along at least one direction of the coordinate system plotted in the figures.

[0062] Preferably, the heat pump 100 comprises an intercooler 42 with an intercooling space 43, wherein an exit 77-1 of the first spiral housing 78-1 is arranged in an upper region 210 of the intercooling space 43 in the operation direction of the heat pump 100, and an entry 79-2 of the second spiral housing 78-2 is arranged in a lower region 220 of the intercooling space 43 in the operation direction of the heat pump 100, so that, in operation of the heat pump 100, a vapor flow takes place in the intercooler 42 from top to bottom (cf. FIG. 8). In the present case, from top to bottom means at least along the negative left direction when considering the coordinate system plotted in the figures. Through this arrangement, the installation space in the heat pump is utilized in a space-efficient manner.

[0063] FIG. 8 shows a section of the inventive heat pump 100 with a cylindrical configuration of the intercooler 42. As shown in FIG. 8, the intercooler 42 consists of two parts that define the upper region 210 and the lower region 220. The upper region 210 is joined to the exit 77-1 of the first spiral housing 78-1. The lower region 220 is jointed to an entry 79-2 of the second spiral housing 78-2 via the bypass pipe 84. Preferably, the upper region 210 and the lower region 220 are built identically, apart from entries and exits. The upper and the lower regions 210, 220 can therefore be manufactured and assembled very easily. Intercooling, i.e. the intercooler 42, can be exchanged flexibly, e.g., the cooling pipes, or cooling rods 48, (cf. FIG. 14) with direct intercooling may be exchanged for coiled cooling pipes 115 (cf. FIG. 15) with indirect intercooling.

[0064] FIG. 9 shows an arrangement of the exit 77-1 of the first compressor stage 70-1 so as to be off-center at the intercooler 42 in an embodiment of the inventive heat pump 100. The exit 77-1 is arranged in the upper region 210. This achieves an optimized swirl of the vapor, leading to a rotation of the swirl in the cylindrical intercooler 42 and therefore to an improved cooling of the steam. The upper region 210 is defined by an upper element 210 and the lower region 220 is defined by a lower element 220. FIG. 12 also shows this off-center arrangement.

[0065] Preferably, the intercooling space 43 is configured of the upper element 210 and the lower element 220, wherein the upper element is connected to the exit 77-1 of the first spiral housing 78-1 and the lower element is connected to the entry 79-2 of the second spiral housing 78-2, and wherein the two elements are connected to each other, in particular connected directly (cf. FIGS. 1, 2 and FIGS. 9 and 12). Alternatively or additionally, in the operation direction of the heat pump 100, the intercooler 42 further comprises the intercooling storage tank 44 arranged below the bottom of the intercooling space 43 and connected to the intercooling space 43 via a pipeline 230 (FIGS. 5 to 7) or integrally connected to the intercooling space 43 (FIGS. 1 and 2), wherein a pump is provided for pumping refrigerant from the intercooling storage tank 44 into the intercooling space 43.

[0066] FIGS. 10 and 11 each show an arrangement of the intercooler 42 in the inventive heat pump 100. FIGS. 10 and 11 show two different perspectives of the heat pump 100. As can be gathered from FIGS. 10 and 11, the intercooler 42 is split into two parts. Through this, the installation space in the heat pump 100 can be better utilized since the split intercooler 42, 44 can be mounted at different locations of the heat pump. The actual intercooler 42 for cooling the steam is preferably located next to the condenser 30. The intercooling storage tank 44 of the intercooler 42 is located below the condenser 30, in particular next to the evaporator 10 (cf. FIG. 11). The intercooler 42 and its intercooling storage tank 44 are connected via a conduit (hose).

[0067] Preferably, the exit 77-1 of the first spiral housing 78-1 is configured as a pipe connection that is attached at the upper element 210 of the intercooling space 43 so as to be off-center with respect to a center axis of the intercooling space 43 so that the axis of the pipe connection passes the center axis of the intercooling space 43 without a point of intersection, wherein the upper element 210 of the intercooling space 43 is configured so as to be essentially cylindrical, wherein, in particular, the outer surface of the pipe connection is attached to the outer part of the intercooling space 43 configured to be cylindrical. In particular, the axis of the pipe connection refers to an axis that extends centrally through the pipe connection. For example, this can be seen in FIGS. 9 and 10.

[0068] FIG. 12 shows a view of cooling rods 48 in the intercooler 42, wherein a cutting ring fitting, as shown in FIG. 13, is used to assemble the cooling rods 48. FIG. 14 shows a further view of cooling rods 48 in the intercooler 42. Preferably, the intercooler 42 comprises one or several cooling rods 48 (cf. FIGS. 8, 12 and 14) extending in the intercooling space 43 from top to bottom in the operation direction of the heat pump 100, wherein nozzle openings 49 are perforated in a lower region of the one or several cooling rods 48 and wherein less or no novel openings are perforated in an upper region, wherein a refrigerant supply is configured to supply refrigerant into the one or the several cooling rods 48 at the upper region so that the refrigerant can be sprayed through the nozzle openings 49 into the intercooling space 43 during operation of the heat pump 100. Through this, operating fluid can be intercooled in the intercooler 42. Preferably, the cooling rods 48 are configured as water pipes with holes (nozzle openings 49). The nozzle openings are used to spray the vapor flowing out in the intercooler 42, i.e. to cool the vapor flowing out in the intercooler 42. FIGS. 12 to 14 each show cooling rods 48. The cooling rods 48 are connected via socket elements 134 by means of cutting ring fittings 130 at a cover plate 132 of the intercooler 42. In FIGS. 12 and 14, an outer wall of the intercooler 42 is indicated only schematically so as to disclose the inside of the intercooler 42.

[0069] The use of an intercooler 42 that is particularly arranged between the first compressor stage 70-1 and the second compressor stage 70-2 makes it possible to cool the vapor of the operating fluid in a stage 1 operation and in a stage 2 operation of the heat pump 100.

[0070] Preferably, the one or the several cooling rods 48 are closed below the nozzle openings 49 in the operation direction of the heat pump 100, in particular, the one or the several cooling rods 48 are squeezed together below the nozzle openings 49 (cf. e.g. FIG. 14). By squeezing them together, the one or the several cooling rods 48 have a conical progression at least in a side view. Alternatively or additionally, the one or the several cooling rods 48 are made of stainless steel, copper, or plastic. Stainless steel and copper are good heat conductors, whereas plastic has a lower weight compared to metal. In any case, the materials mentioned are robust and therefore have a long service life. Preferably, the one or the several cooling rods 48 are attached to a cover element 132 (cover plate 132) of the upper element of the intercooling space 43 via one or several socket elements 134, wherein the socket elements 134 extend through the cover element 132 and comprise refrigerant connections outside of the intercooling space 43. Preferably, the one or the several cooling rods 48 are attached to the sockets elements 134 by one or several cutting ring fixings 130, respectively, said socket elements being connected to the cover element 132 of the intercooling space 43.

[0071] FIG. 13 shows a cutting ring fitting 130. Cutting ring fittings are normed according to DIN EN ISO 8434 (parts 1.4), or DIN 2353, and are used in the field of hydraulics, above all. The parts of a cutting ring fitting are as follows: union nut, clamping cone, and cutting ring. It has a sealing cone of 24°, the nut has a metric thread (cf. Wikipedia). In particular, the cutting ring fitting 130 is used in metallic cooling rods 48. Other assembly possibilities for fixing the cooling rods 48 to the intercooler 42 are also considerable.

[0072] Preferably, the one or several cooling rods 48 do not have any perforations 148 in a portion 140, in particular the upper portion, and have perforations 148 in another portion 142, in particular a lower portion, wherein the portion 140, in particular an upper portion, is dimensioned for indirect cooling, and the other portion 142, in particular a lower portion, is dimensioned for direct cooling. Direct cooling includes spraying with refrigerant, wherein indirect cooling only includes heat transfer between the one or the other cooling rods 48. Preferably, the upper portion 140 is longer than the lower portion 142. Additionally or alternatively, the one or several cooling rods 48 comprise in the upper portion 140 a surface that is configured to be more inhomogeneous than compared to the lower portion 142. The surface configured to be more inhomogeneous may comprise a greater roughness and therefore a larger surface compared to the surface of the lower portion 142, so as to improve the heat transfer between an interior of the one or several cooling rods 48 and the intercooling space 43. The perforations 148 are configured as nozzle openings 49 that may have varying opening diameters. Preferably, the perforations 148 or the nozzle openings 49 are configured as laser holes. By changing the proportion of indirect cooling (without perforations 148 in a portion 140) and direct cooling (with perforations 148 in the other portion 142) of the cooling rods 48, the cooling capacity of the intercooler 42 may be adapted variably. Preferably, three cooling rods 48 are provided in the intercooler 42. However, there may be more or less than three cooling rods 48. Instead of cooling rods 48 extending in a straight line, there may be more or fewer cooling pipes. For example, the cooling pipe may be configured to be spiral-shaped or coiled. The pipes may also have ribs or may be configured with a rough surface in the region of indirect cooling (in the region 140) so as to increase the heat transfer surface area.

[0073] Alternatively, the intercooling space 43 preferably comprises one or several coiled cooling pipes 115 (cf. FIG. 15). Preferably, according to an alternative, the heat pump 100 described herein comprises cooling rods 48, wherein the one or the several cooling rods 48 are configured as coiled cooling pipes 115, wherein the one or the several coiled cooling pipes 115 comprise an end arranged in the intercooling space 43, said end being arranged such that cooling liquid exiting the end, or ends, can be sprayed from bottom to top into the intercooling space 43 in the operation direction of the heat pump 100 (cf. arrow 116 in FIG. 15), or wherein the one or several coiled cooling pipes 115 comprise nozzle openings 49 configured to spray refrigerant from bottom to top in an intercooling space 43. The arrow 116 in FIG. 15 schematically shows cooling liquid being sprayed into the intercooling space 43. The arrow 117 shows the vapor direction of the compressed operating fluid. As shown in FIG. 15, e.g. instead of the cooling rods 48 that “hang” downwards, a coiled cooling pipe 115 comprising a larger length for indirect cooling of the vapor than the cooling rods 48 extending in a straight line may be used. The cooling water exiting the cooling pipe 115 (in the direction of the arrow 116) is sprayed opposite to the vapor direction 117, causing improved cooling of the vapor (cf. FIG. 15).

[0074] Preferably, the second spiral housing 78-2 comprises a second exit pipe 145, wherein the intercooler 42 comprises an intercooler exit pipe 45 leading to the condenser 30. The second exit pipe 145 is connected to the first intercooler exit pipe 45. Alternatively or additionally, the second exit pipe 145 may directly lead to the condenser 30. FIG. 16 shows both possibilities. The second exit pipe 145 may be interpreted as a “stage 2 exit pipe,” since the second exit pipe 145 leads the steam exiting the second compressor stage 70-2 directly to the condenser 30 and / or via the intercooler exit pipe 45. The intercooler exit pipe 45 may be interpreted as a “stage 1 exit pipe,” wherein the intercooler exit pipe 45 leads the vapor exiting the first compressor stage 70-1 directly to the condenser 30. By docking the second exit pipe 45 to the intercooler exit pipe 45, e.g., a connection to the condenser 30 can be omitted if the second exit pipe 145 does not comprise a direct connection to the condenser (not illustrated in FIG. 16). Through this, the insulation space may be better utilized through the arrangement of the other components of the heat pump.

[0075] FIG. 17 shows an arrangement of a bypass pipe 84 in the inventive heat pump 100. Preferably, the heat pump 100 comprises the bypass pipe 84, wherein a first end 151 of the bypass pipe 84 leads to the condenser 30, wherein a second end 152 of the bypass pipe 84 leads to the evaporator 10, and wherein the second end 152 of the bypass pipe 84 leads to the evaporator 10 below a sprinkling in the evaporator 10 and above a level of an evaporator sump 16 (cf. reference numerals 161 in FIG. 17), and / or wherein the first end 151 of the bypass pipe 84 leads to the condenser 30 below the upper end of the condenser 30 and above the level of the condenser sump 36 (cf. reference numerals 161 in FIG. 17). The reference numerals 161 and 162 indicate the regions in which the first and second end 151, 152 may each be arranged.

[0076] Similar to FIG. 11, FIG. 18 shows an arrangement of the intercooler 42 in the inventive heat pump 100, wherein the intercooling storage tank 44 (cf. FIG. 10) is arranged separately from the intercooler 42. FIG. 18 shows the intercooler 42 with its bottom edge 143. Fundamentally, the intercooling storage tank 44 of the intercooler 42 may be arranged everywhere in the heat pump 100 below the bottom edge 143 of the intercooler 42 (cf. FIGS. 18 and 11). The intercooling storage tank 44 may be configured of plastic or stainless steel or any other metal that reacts little with water or not at all.

[0077] The second spiral housing 78-2 preferably comprises an input connection 26 connected to a connection pipe 28 (cf. FIG. 19), wherein a further droplet separator 55 is configured in the connection pipe 28 so as to reduce or eliminate operating fluid droplets in a vapor flow into the second spiral housing 78-2. In particular, the vapor flow specifies the operation direction of the heat pump 100. The droplet separators 55 arranged in the heat pump 100 are used to separate operating liquid droplets from operating vapor. FIG. 19 schematically shows the arrangement of a droplet separator 55 (indicated by its reference numeral) in front of the second compressor in the connection pipe 28 in the inventive heat pump 100. The connection pipe 28 is also referred to as bypass pipe 84. A second droplet separator 55 is arranged between the exit of the intercooler 42 and the second compressor stage 70-2 so as to prevent that droplets are drawn out of the water vapor, or out of the intercooler 42, into the second compressor stage 70-2 and damage the same. A first droplet separator 55 is arranged in the intake socket 52 (cf. FIG. 19).

[0078] FIG. 19 further shows a burst bucket 90 put over the first drive motor 80-1 of the first compressor stage 70-1. Preferably, the first spiral housing 78-1 and / or the second spiral housing 78-2 is attached to a rack 40 of the heat pump 100 via at least one elastic damping element 94. Preferably, a safety element 95 is arranged between the rack 40 and the first spiral housing 78-1 and / or the second spiral housing 78-2 in the heat pump 100 so as to essentially hold in place the first spiral housing 78-1 and / or the second spiral housing 78-2, in particular within the rack 40, in the case of destruction of the at least one elastic damping element 94. The safety element 95 is preferably arranged in the region of the drive motors 80-1, 80-2 so as to protect the first spiral housing 78-1 and / or the second spiral housing 78-2 from parts of the drive motors 80-1, 80-2, or the impellers, flying around in case that the drive motors 80-1, 80-2 no longer function.

[0079] In the case of the impeller bursting due to material failure, etc., the impeller will become entrenched in the spiral housing 78-1 and 78-2, or wedged in, and will apply a torque 190 to the spiral housing 78-1, 78-2. In this case, the damping element 94 will be the weakest spot. In this case, the compressor stage 70-1, 70-2 with the spiral housing 78-1, 78-2 will tumble in the opening of the rack 40 and possibility be released.

[0080] Thus, a safety element 95 is proposed between the rack 40 and the spiral housing 78-1, 78-2, for example an arresting cable, a screw connection, a catching device 89 or the like that “catches” the spiral housing 78-1, 78-2 in case of the impeller bursting.

[0081] FIGS. 20 to 21 show different schematic views of the spiral housing 78-1, 78-2 so as to highlight the design of such a housing. FIG. 20 shows different views of a schematic design of a spiral housing 78-1, 78-2. FIG. 20a shows a perspective 3-dimensional view of a spiral housing 78-1, 78-2 having attached thereon a drive motor 80-1, 80-2. FIG. 20b shows a top view of the spiral housing 78-1, 78-2 having attached thereon the drive motor 80-1, 80-2. A diameter 205 of the evolute of approximately 500 mm, for example, can be gathered from FIG. 20b, wherein an exit 201 of the evolute comprises a diameter 205 of approximately 90 mm. The exit 201 of the evolute corresponds to the exits 77-1, 77-2 of the spiral housings 78-1, 78-2, which can also be seen in FIG. 20c. FIGS. 20c and 20d each show a side view of the spiral housing 78-1, 78-2, wherein FIG. 20c shows the entry 79-1, 79-2 of the spiral housing 78-1, 78-2. The entries 79-1, 79-2 have a diameter 205 of approximately 10 mm. FIG. 20d shows in detail the shape of the spiral housing 78-1, 78-2, comprising an upper part 202 in the form of a plate and a bottom part 203 with a U-profile, wherein the diameter of the U-profile increases up to the exit 201 of the evolute. FIG. 21 shows in magnified way the schematic structure of the upper part 202 on the plate of the spiral housing 78-1, 78-2, wherein the upper part 201 comprises a recess 204 or opening 204 for receiving the drive motor 80-1, 80-2. FIG. 22 shows in a magnified way the schematic structure of the bottom part 203 of the spiral housing 78-1, 78-2, wherein a center of the vapor entry (air inlet 56) and a center of the spiral housing 78-1, 78-2 are on an axis N. FIG. 23 and FIG. 24 show further details in top views and side views of the spiral housing 78-1, 78-2.

[0082] Preferably, the first spiral housing 78-1 or the second spiral housing 78-1 comprise the following features: a central air inlet 56; a lateral air outlet 57; a planar connection channel 66 adjacent to the air inlet 56; and an evolute channel 62 connecting the planar connection region 66 and the air outlet 57, wherein evolute channel 62 comprises a cross-sectional area that continuously increases from the air inlet 56 towards the air outlet 57, and wherein the evolute channel 62 is curved and extends from the air inlet 56 to the air outlet 57 by more than 180 degrees and by less than 360 degrees (cf. FIGS. 20 to 24).

[0083] Preferably, the evolute channel 62 comprises a diameter of more than 70 mm and less than 110 mm at the air entry opening, or at the air inlet 56, wherein a diameter of the first spiral housing 78-1 and / or of the second spiral housing 78-2 is between 400 and 600 mm, or wherein a ratio between the diameter of the first or the second spiral housing 78-1, 78-2 and the diameter of the air outlet 57 is between (two) 2 and (ten) 10, in particular between (three) 3 and (eight) 8, in particular between (four) 4 and (seven) 7 (cf. FIGS. 20 to 24).

[0084] Preferably, the planar connection region 66, or the planar connection channel 66, extends around the air inlet 56 by more than 270 degrees and less than 360 degrees, and has a height that is at most half of a height of the evolute channel 62 at the air exit, or air outlet 57 (cf. FIGS. 20 to 24).

[0085] Preferably, the evolute channel 62 increases in its cross-sectional area along a rotational sense, wherein the rotational sense is directed same as the rotational sense of the first compressor motor 17) and / or the second compressor motor 18. The first compressor motor 17 corresponds to the first drive motor 80-1. The second compressor motor 18 corresponds to the second drive motor 80-2.

[0086] Preferably, the first spiral housing 78-1 and / or the second spiral housing 78-2 are formed on a base plate 64 and an evolute plate 63, wherein the evolute plate 63 comprises a surrounding U-profile, whose cross-section continuously increases, for defining the evolute channel 62, or wherein the first spiral housing 78-1 and / or the second spiral housing 78-2 is formed of an integrally generated cast part 65, wherein the evolute channel 62 and / or the planar connection channel 66 are defined by a sacrificial core 67. The evolute plate 63 corresponds to the bottom part 203 and the base plate 64 corresponds to the upper part 202.

[0087] The heat pump 100 described herein comprises a space-efficient arrangement of its individual components. In addition, the individual components of the heat pump 100 are arranged such that the flow of the operating fluid is optimized with respect to its flow during operation of the heat pump 100, in particular by the tanks and the spiral housings 79-1, 79-2.

[0088] A further aspect of the present invention concerns a method 250 for manufacturing a heat pump 100 with an evaporator 10 for evaporating operating liquid so as to obtain operating vapor; a compressor 20 for compressing the operating vapor so as to obtain compressed operating vapor; and a condenser 30 for condensing the compressed operating vapor, wherein the condenser 20 comprises a first compressor stage 70-1 and a second compressor stage 70-2, wherein the first compressor stage 70-1 comprises a first spiral housing 78-1, a first drive motor 80-1, and a first drive shaft 86-1, wherein the second compressor stage 70-2 comprises a second spiral housing 78-2, a second drive motor 80-2, and a second drive shaft 86-2. In step 252, the method 250 includes arranging the drive shafts 86-1, 86-2 so that the first drive shaft 86-1 is separate from the second drive shaft 86-2. Through this, the drive motors 80-1, 80-1 may be operated independently from each other. In step 254, the method 250 includes configuring the first drive shaft 86-1 so as to be standing in an operation direction of the heat pump 100. Configuring the same so as to be standing corresponds to arranging the first drive shaft 86-1 essentially perpendicular to a surface on which the heat pump 100 is set up. The operation direction of the heat pump is the direction in which an operating liquid is evaporated, or compressed, or condensed. The operation direction of the heat pump 100 indicates a flow direction of the operating liquid, or the operating fluid. Thus, the operation direction of the heat pump 100 is not constant, but depends on spatial conditions of the individual components of the heat pump 100, which the operating fluid passes during operation of the heat pump. The method 250 is shown in FIG. 25.

[0089] A further aspect of the present invention concerns a method 260 for operating a heat pump 100 with an evaporator 10 for evaporating operating liquid so as to obtain operating vapor; a compressor 20 for compressing the operating vapor so as to obtain compressed operating vapor; and a condenser 30 for condensing the compressed operating vapor, wherein the compressor 20 comprises a first compressor stage 70-1 and a second compressor stage 70-2, wherein the first compressor stage 70-1 comprises a first spiral housing 78-1, a first drive motor 80-1, and a first drive shaft 86-1, wherein the second compressor stage 70-2 comprises a second spiral housing 78-2, a second drive motor 80-2, and a second drive shaft 86-2, wherein the first drive shaft 86-1 is separate from the second drive shaft 86-2. In step 262, the method 260 includes setting up the heat pump 100 in an operation direction. In particular, the heat pump is arranged on the earth surface. At the start of an operation cycle of the heat pump, the operation direction of the heat pump 100 is essentially perpendicular to the earth surface. In step 264, the method 260 includes operating the heat pump 100 in the operation direction so that the first drive shaft 86-1 is configured so as to be standing in the operation direction of the heat pump 100, in particular essentially perpendicular to the surface. The method 260 is shown in FIG. 26.

[0090] The method 250 and the method 260 each include steps for manufacturing and operating the heat pump 100 as described in connection with its apparatus features herein.

[0091] Even though some aspects are described in connection with an apparatus, or system, it is understood that these aspects also represent a description of a corresponding method, so that a block or component of an apparatus, or system, can also be understood as a corresponding method step or as a feature of a method step. A representation of the present invention in the form of method steps is omitted for reasons of redundancy.

[0092] In the above detailed description, different features were partially grouped in examples so as to rationalize the disclosure. This type of disclosure is not to be interpreted with the intent that the claimed examples have more features than explicitly indicated in each claim. Rather, as expressed by the following claims, the subject-matter may be within fewer than all of the features of a single disclosed example. Consequently, the following claims are incorporated hereby into the detailed description, wherein each claim can stand as its own separate example. While each claim can stand as its own separate example, it is to be noted that, even though dependent claims in the claims refer back to a specific combination with one or several other claims, other examples also include a combination of dependent claims with the subject-matter of each other dependent claim or a combination of each feature with other dependent or independent claims. Such combinations are included unless is indicated that a specific combination is not intended. Furthermore, it is intended that a combination of features of a claim with each other independent claim is included, even if this claim does not directly depend on the independent claim.LIST OF REFERENCE NUMERALS10 evaporator

[0094] 11 evaporator tank

[0095] 15 evaporator cylinder

[0096] 16 evaporator sump

[0097] 17 first compressor motor

[0098] 18 second compressor motor

[0099] 20 compressor

[0100] 21 compressor tank

[0101] 26 entry connection

[0102] 28 connection pipe

[0103] 30 condenser

[0104] 36 condenser sump

[0105] 31 condenser tank

[0106] 35 condenser cylinder

[0107] 36 entry of the condenser

[0108] 40 rack

[0109] 42 intercooler

[0110] 43 intercooling space

[0111] 44 intercooling storage tank

[0112] 45 intercooling exit pipe

[0113] 46 exit of the intercooling space

[0114] 47 entry of the intercooling space

[0115] 48 cooling rod

[0116] 49 nozzle opening

[0117] 52 intake socket

[0118] 54 droplet separator

[0119] 55 further droplet separator

[0120] 56 air inlet

[0121] 57 air outlet

[0122] 62 evolute channel

[0123] 63 evolute plate

[0124] 64 base plate

[0125] 65 mold part

[0126] 66 connection channel

[0127] 67 sacrificial core

[0128] 70-1 first compressor stage

[0129] 70-2 second compressor stage

[0130] 77-1 exit of the first spiral housing

[0131] 77-2 exit of the second spiral housing

[0132] 78 spiral housing

[0133] 78-1 first spiral housing

[0134] 78-2 second spiral housing

[0135] 79-1 entry of the first spiral housing

[0136] 79-2 entry of the second spiral housing

[0137] 80 drive motor

[0138] 80-1 first drive motor

[0139] 80-2 second drive motor

[0140] 82 hatch

[0141] 84 bypass pipe

[0142] 85 bypass strand

[0143] 86-1 first drive shaft

[0144] 86-2 second drive shaft

[0145] 90 burst bucket

[0146] 94 elastic banding element

[0147] 95 safety element

[0148] 98 catching device

[0149] 100 heat pump

[0150] 115 coiled cooling pipe

[0151] 116 arrow

[0152] 117 arrow

[0153] 130 cutting ring fitting

[0154] 132 copper plate of the intercooler

[0155] 134 socket element

[0156] 151 first end

[0157] 152 second end

[0158] 161 region

[0159] 162 region

[0160] 190 torque

[0161] 200 slope

[0162] 201 exit of the evolute

[0163] 202 upper part

[0164] 203 bottom part

[0165] 204 recess / opening

[0166] 205 diameter of the evolute

[0167] 210 upper element

[0168] 220 lower element

[0169] 140 portion

[0170] 142 other portion

[0171] 143 bottom edge of the intercooler

[0172] 145 second exit pipe

[0173] 148 perforation

[0174] 1′ chamber

[0175] 2′ chamber

[0176] 3 chamber

[0177] 4 storage tank

[0178] 5 rotor discs are on a drive shaft

[0179] 6 evaporator

[0180] 7 water refrigerant heat pump system

[0181] 10′ refrigerator

[0182] 12′ compressor part

[0183] 14′ condenser

[0184] 16′ evaporator

[0185] 18 outlet spiral

[0186] 20′ pipeline

Claims

1. A heat pump, comprising:an evaporator for evaporating operating liquid so as to obtain operating vapor;a compressor for compressing the operating vapor so as to obtain compressed operating vapor; anda condenser for condensing the compressed operating vapor,wherein the compressor comprises a first compressor stage and a second compressor stage, wherein the first compressor stage comprises a first spiral housing, a first drive motor, and a first drive shaft, wherein the second compressor stage comprises a second spiral housing a second drive motorand a second drive shaft,wherein the first drive shaft is separate from the second drive shaft andwherein the drive shaft is configured to be standing in an operation direction of the heat pump2. The heat pump according to claim 1, wherein the evaporator is configured as a recumbent evaporator cylinder and wherein the condenser is configured as a recumbent condenser cylinder, wherein the recumbent condenser cylinder is arranged obliquely above the recumbent evaporator cylinder in the operation direction of the heat pump, and wherein, in particular, the evaporator cylinder and the condenser cylinder at least partially overlap vertically (to the operation direction).

3. The heat pump according to claim 1, wherein an intercooler comprising an intercooling space and an intercooling storage tank is arranged between the first compressor stage and the second compressor stage,wherein the intercooling space is configured to be integrated with the intercooling storage tank, and / or wherein the intercooling space is arranged above the evaporator, orwherein the intercooling storage tank is arranged below the condenser sump configured in the condenser, and above the evaporator sump configured in the evaporator.

4. The heat pump according to claim 1, wherein the second drive shaft is arranged to be recumbent in the operation direction of the heat pump,wherein the first spiral housing is arranged to be recumbent and the second spiral housing is arranged to be standing.

5. The heat pump according to claim 3, wherein the intercooling space is arranged above the condenser or at least partially overlaps the same vertically and wherein the intercooling space is arranged between the first spiral housing and the second spiral housing, and / or wherein the intercooling storage tank is arranged separate from the intercooling space below the condenser, orwherein an essentially straight or U-shaped bypass pipe is arranged between the condenser and the evaporator in a region in which the condenser and the evaporator at least partially overlap vertically in the operation direction of the heat pump.

6. The heat pump according to claim 1, wherein an intake socket arranged outside of the evaporator is arranged between the evaporator and the first compressor stage, orwherein an intake socket arranged outside of the evaporator is arranged between the evaporator and the first compressor stage, wherein a droplet separator is arranged in the intake socket, orwherein an intake socket arranged outside of the evaporator and having a length that is at least as large as half of the diameter of the condenser is arranged between the evaporator and the first compressor stage, and / or wherein the intake socket is arranged to be standing.

7. The heat pump according to claim 6, wherein an entry of the first spiral housing arranged to be recumbent is arranged at the top of the intake socket in the operation direction of the heat pump wherein an exit of the first spiral housing is connected to an entry of an intercooling space of an intercooler,wherein an exit of the intercooling space is connected to an entry of the second spiral housing arranged to be recumbent, and an exit of the second spiral housing is connected to an entry of the condenser, wherein the respective connections are preferably configured directly, and / orwherein the first spiral housing, the second spiral housing, and the condenser are arranged such that, during operation of the heat pump, a vapor flow is caused through the intake socket in a first direction, a vapor flow is caused through the intercooling space in a second direction essentially perpendicular to the first direction, and a vapor flow is caused from the second spiral housing into the condenser in a third direction having at least one directional component that is directed essentially opposite to the first direction, and wherein the first spiral housing and the second spiral housing are arranged and configured to each cause a vapor flow direction change of essentially 90 degrees.

8. The heat pump according to claim 1, wherein the first compressor stage comprises a first impeller wheel arranged at the first drive shaft wherein the second compressor stage comprises a second impeller wheel attached to the second drive shaft, wherein the first drive shaft and the second drive shaft are arranged essentially in parallel, wherein the first impeller wheel and the second impeller wheel are arranged at essentially the same height, orwherein, in the operation direction of the heat pump, the first drive shaft and the second drive shaft are arranged essentially perpendicular to each other and the first impeller wheel comprises a length and the second impeller wheel comprises a diameter, wherein the first impeller wheel and the second impeller wheel are arranged such that the length of the first impeller wheel and the diameter of the second impeller wheel overlap essentially at least partially.

9. The heat pump according to claim 1, comprising an intercooler with an intercooling space, wherein an exit of the first spiral housing is arranged in an upper region of the intercooling space in the operation direction of the heat pump, and an entry of the second spiral housing is arranged in a lower region of the intercooling space in the operation direction of the heat pump, so that, in operation of the heat pump, a vapor flow takes place from top to bottom in the intercooler10. The heat pump according to claim 9, wherein the intercooling space configured of an upper element and a lower element, wherein the upper element is connected to the exit of the first spiral housing, and the lower element is connected to the entry of the second spiral housing, and wherein the two elements are connected to each other, in particular connected directly, and / orwherein, in the operation direction of the heat pump, the intercooler further comprises the intercooling storage tank arranged below the bottom of the intercooling space and via which a pipeline is connected to the intercooling space or is integrally connected to the intercooling space wherein a pump is provided for pumping a refrigerant from the intercooling storage tank into the intercooling space configured to be cylindrical.

11. The heat pump according to claim 9, wherein the exit of the first spiral housing is configured as a pipe connection attached at the upper element of the intercooling space so as to be off center with respect to a center axis of the intercooling space so that the axis of the pipe connection passes the center axis of the intercooling space without point of intersection, wherein the upper element of the intercooling space is configured to be essentially cylindrical, wherein, in particular, the outer surface of the pipe connection is attached to the outer part of the intercooling space configured to be cylindrical.

12. The heat pump according to claim 9, wherein the intercooler comprises one or several cooling rods extending in the intercooling space from top to bottom in the operation direction of the heat pump, wherein nozzle openings are perforated in a lower region of the one or several cooling rods, and wherein fewer or no nozzle openings are perforated in an upper region, wherein a refrigerant supply is configured to supply refrigerant into the one or the several cooling rods at the upper region so that the refrigerant can be sprayed into the intercooling space through the nozzle openings during operation of the heat pump13. The heat pump according to claim 12, wherein the one or the several cooling rods are closed below the nozzle openings in the operation direction of the heat pump, in particular, wherein the one or the several cooling rods are squeezed together below the nozzle openings, and / orwherein the one or the several cooling rods are configured of stainless steel, copper, or plastic, and / orwherein the one or the several cooling rods are joined to a cover element of the upper element of the intercooling space via one or several socket elements, wherein the socket elements extend through the cover element and comprise refrigerant connections outside of the intercooling space and / orwherein the one or the several cooling rods are attached to the socket elements connected to the cover element of the intercooling space via one or several cutting ring fittings, respectively.

14. The heat pump according to claim 12, wherein the one or the several cooling rods comprise no perforations in one portion and comprise the perforations in another portion, wherein the one upper portion is dimensioned for indirect cooling and the other lower portion is dimensioned for direct cooling, and / or wherein the upper portion is longer than the lower portion, and / or wherein the one or the several cooling rods comprise in the upper portion a surface that is configured to be more inhomogeneous compared to the lower portion.

15. The heat pump according to claim 12, wherein the intercooling space comprises one or several coiled cooling pipes, or the heat pump wherein the one or the several cooling rods are configured as coiled cooling pipes, wherein the one or the several coiled cooling pipes comprise an end arranged in the intercooling space, said end or ends being arranged such that cooling liquid exiting the end or the ends can be sprayed into the intercooling space from bottom to top into the operation direction of the heat pump, or wherein the one or the several coiled cooling pipes comprise nozzle openings configured to spray refrigerant from bottom to top into a intercooling space16. The heat pump according to any of the preceding claim 1, wherein the second spiral housing comprises a second exit pipe, wherein the intercooler comprises an intercooler exit pipe ending in the condenser, and wherein the second exit pipe is connected to the first intercooler exit pipe.

17. The heat pump according to claim 1, comprising a bypass pipe, wherein a first end of the bypass pipe ends in the condenser, wherein a second end of the bypass pipe ends in the evaporator, and wherein the second end of the bypass pipe leads to the evaporator below a sprinkling in the evaporator and above a level of an evaporator sump, and / or wherein the first end of the bypass pipe leads to the condenser below the upper end of the condenser and above the level of the condenser sump18. The heat pump according to claim 1, wherein the second spiral housing comprises an entry connection connected to the connection pipe, wherein a further droplet separator is configured in the connection pipe to reduce or eliminate operating liquid droplets in a vapor flow into the second spiral housing.

19. The heat pump according to claim 1, wherein the first spiral housing and / or the second spiral housing are attached to a rack via at least one elastic damping element, and wherein a safety element is arranged between the rack and the first spiral housing and / or the second spiral housing to hold the first spiral housing and / or the second spiral housing in essentially the same position, in particular within the rack, in case of destruction of the at least one elastic damping element.

20. The heat pump according to claim 1, wherein the first spiral housing or the second spiral housing comprises:a central air inlet;a lateral air outlet;a planar connection channel adjacent to the air inlet;an evolute channel connecting the planar connection region to the air outlet,wherein the evolute channel comprises a cross-sectional area that continuously increases from the air inlet to the air outlet, and wherein the evolute channel is curved and extends from the air inlet to the air outlet by more than 180 degrees and less than 360 degrees.

21. The heat pump according to claim 20, wherein the evolute channel comprises at the air entry opening a diameter of more than 70 mm and less than 110 mm, wherein a diameter of the first spiral housing and / or the second spiral housing is between 400 mm and 600 mm, or wherein a ratio of the diameter of the first or the second spiral housing and the diameter of the air outlet is between 2 and 10, in particular between 3 and 8, and in particular between 4 and 7.

22. The heat pump according to claim 20, wherein the planar connection region extends around the air inlet by more than 270 degrees and less than 360 degrees, and comprises a height that is at most half of a height of the evolute channel at the air outlet.

23. The heat pump according to claim 20, wherein the evolute channel increases in its cross-sectional area along a rotational sense, wherein the rotational sense is directed same as the rotational sense of the first compressor motor and / or the second compressor motor.

24. The heat pump according to claim 20, wherein the first spiral housing or the second spiral housing is formed of a base plate and an evolute plate, wherein the evolute plate comprises a surrounding U-profile, whose cross-section continuously increases, for defining the evolute channel, or wherein the first spiral housing or the second spiral housing is formed of an integrally generated cast part, wherein the evolute channel and the planar connection channel are defined by a sacrificial core25. A method for manufacturing a heat pump, comprising: an evaporator for evaporating operating liquid so as to obtain operating vapor; a compressor for compressing the operating vapor so as to obtain compressed operating vapor; and a condenser for condensing the compressed operating vapor, wherein the compressor comprises a first compressor stage and second compressor stage, wherein the first compressor stage comprises a first spiral housing, a first drive motor and a first drive shaft, wherein the second compressor stage comprises a second spiral housing, a second drive motor, and a second drive shaft comprising:arranging the drive shafts so that the first drive shaft is separate from the second drive shaft, andconfiguring the first drive shaft so as to be standing in an operation direction of the heat pump.

26. A method for operating a heat pump, comprising: an evaporator for evaporating operating liquid so as to obtain operating vapor; a compressor for compressing the operating vapor so as to obtain compressed operating vapor; and a condenser for condensing the compressed operating vapor,wherein the compressor comprises a first compressor stage and a second compressor stage, wherein the first compressor stage comprises a first spiral housing a first drive motorand a first drive shaft wherein the second compressor stage comprises a second spiral housing, a second drive motorand a second drive shaft, wherein the first drive shaft is separate from the second drive shaft, comprising:setting up the heat pump in an operation direction; andoperating the heat pump in the operation direction so that the first drive shaft is configured to be standing in the operation direction of the heat pump

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