WO2023194475A1

WO2023194475A1 - Heat pump

Info

Publication number: WO2023194475A1
Application number: PCT/EP2023/059007
Authority: WO
Inventors: Florian Hanslik; Thaddäus Hinterberger; Lennart Thomsen
Original assignee: Efficient Energy Gmbh
Priority date: 2022-04-07
Filing date: 2023-04-05
Publication date: 2023-10-12
Also published as: DE102022203526A1

Abstract

A heat pump (100) with an evaporator (50) for evaporating a fluid in order to obtain evaporated fluid is described; with a condenser (60) for condensing a compressed fluid; with a compressor having a first compressor stage (10) and a second compressor stage (20), the compressor being arranged in the flow direction of the evaporated fluid during operation of the heat pump (100) between the evaporator (50) and the condenser (60) and being designed to compress the evaporated fluid in order to obtain compressed fluid; and with a bridging duct (62) between the first compressor stage (10) and the condenser (60) in order to bridge the second compressor stage (20), a cross-section reducing element (70) being arranged in the bridging duct (62) in order to adjust a cross section of the bridging duct (62) so as to control a flow of compressed fluid from the first compressor stage (10) to the condenser (60). Furthermore, methods for operating and producing the heat pump are described.

Description

Heat pump

Description

The present invention relates to the field of heat pumps and, more particularly, to concepts for improving the efficiency of a heat pump.

EP 3 203 164 describes a heat pump. 20 shows prior art from EP 3 203 164. The heat pump of EP 3 203 164 is operated with water as a refrigerant. The water is led from the sump of the condenser 6' through the supply line 71' to the sump of the intermediate cooling. The feed line 71' goes from the sump of the intermediate cooling to the sump of the evaporator 2', which allows the refrigerant to be returned. From the sump 4a' of the intermediate cooling 4', the further supply line 72' goes to the sump of the evaporator 2', whereby the refrigerant is returned to the evaporator. Through the pump 4c', the cooling water for irrigation is fed to the top of the intermediate cooling container 41' to cool the superheated water vapor leaving the compressor 3'. EP 3 203 164 discloses direct cooling with direct irrigation. With direct irrigation, the superheated steam flowing from the first compressor is cooled down to saturated steam temperature by sprinkling water from the sump of the intercooler. The irrigation can form droplets that are carried along by the steam towards the second compressor 5' and can damage it due to the impact of the droplets on the impeller. In addition, the superheated steam is only cooled in the intercooler. The water collected in the intermediate cooling sump therefore already corresponds almost to the saturated steam temperature. In order to deheat the superheated steam to the saturated steam temperature level, a relatively large surface area and a long contact time between water and steam are required. Refrigeration systems are usually only limited to a limited range of power output. In order to be able to react to higher and lower cooling capacities at the same time, the compressors often have to be switched on/off. In EP 3 203 164 B, for example, a flap is provided between the different compressors.

In the publication Novel Turbo Compressor for Heat Pump Using Water as Refrigerant and Lubricant by T. Shoyama et al. 2019, IOP Conf.: Mater. Be. Closely. 604 011010 is a compressor for a heat pump with a steam bypass V0 described, which taps the steam directly after the compressor (see Fig. 21). The steam flow goes from the output of the second compressor C2 back to the input of the first compressor C1.

The power consumption of the first compressor stage usually serves as a reference variable for the second compressor stage. This means that the two compressor stages (first and second compressor stages) contribute a similar pressure ratio to the overall pressure ratio, since both rotate at approximately the same speed. As a result, the flow through the second compressor is not optimal. This becomes particularly problematic at high pressure conditions because the power consumption of the first compressor results in a variance in vapor volume flows due to the ambient temperature and the control of the second compressor. The liquefaction and re-evaporation in the intermediate circuit leads to a thermodynamic loss, so that the pressure ratios of the compressor stages do not fully contribute to the overall compression ratio. This is a problem particularly for the second compressor.

The object of the present invention is to create an improved heat pump, which in particular has an improved concept for heat exchange of a fluid circulating in the heat pump, such as a cooling liquid.

This task is solved by a heat pump according to claim 1.

The heat pump according to the present invention includes an evaporator for evaporating a fluid to obtain evaporated fluid; a condenser for condensing a compressed fluid; a compressor with a first compressor stage and a second compressor stage, the compressor being arranged in the flow direction of the evaporated fluid in an operation of the heat pump between the evaporator and the condenser and being designed to compress the evaporated fluid to obtain compressed fluid; and a bypass channel between the first compressor stage and the condenser to bridge the second compressor stage, wherein a cross-section reducing element is arranged in the bypass channel to adjust a cross section of the bypass channel to regulate a flow of compressed fluid from the first compressor stage to the condenser. It goes without saying that individual aspects that are described in relation to the heat pump can also be implemented as a process step and vice versa. Further details are discussed in the image description below.

Preferred embodiments of the present invention are explained in detail below with reference to the accompanying drawings. Show it:

Fig. 1 is a hydraulic diagram of the heat pump according to the invention;

2 shows an enlarged section of the hydraulic diagram according to FIG. 1, with a steam flap (upper section) and a steam bypass flap (lower section) being shown;

3 shows a schematic test stand which is used to test the functionality of the compressors of the heat pump under real operating conditions;

4 shows a schematic structure of an N-stage compression, where in the case shown N=3;

Fig. 5 is a hydraulic diagram of the N-stage compression;

6 shows a three-dimensional view of the heat pump according to the invention;

Fig. 7 shows a top view (Fig. 7a) and a side view (Fig. 7b) of the

Cross-sectional reducing element and a connection of the cross-sectional reducing element (Fig. 7c);

8 shows a hydraulic diagram in which a circuit for indirect intermediate cooling is shown;

Fig. 9 is a hydraulic diagram of indirect intercooling with an indirect heat exchanger;

Fig. 10 is a sketch of a side view of a heat exchanger tube; Fig. 11 is a diametrical perspective view of the heat exchanger;

12 shows a hydraulic diagram showing a supply of the intercooling, the intercooling being fed from the evaporator sump;

13 shows a hydraulic diagram showing a supply of the intermediate cooling, with a sketched heat exchanger, the intermediate cooling being fed from the evaporator sump;

14 shows a hydraulic diagram showing a supply of the intermediate cooling, with additional packing and/or additional intermediate cooling, the intermediate cooling being fed from the evaporator sump;

Fig. 15 shows a compressor map;

16 shows a three-dimensional envelope surface over a corrected mass flow;

17 shows a three-dimensional representation for determining the volume flow to determine the corrected mass flow;

18 is a hydraulic schematic highlighting temperature sensors for guiding the second compressor;

Fig. 19 Scheme to illustrate a control of the compressor stages of the heat pump;

20 shows a hydraulic diagram of a heat pump known from the prior art; and

Fig. 21 is a hydraulic diagram of a heat pump known from the prior art with steam bypass.

Individual aspects of the invention described herein are shown below in Figures. 1 to 15 described. In the present application, the same reference numerals refer to the same or elements with the same effect, although not all reference symbols in all drawings, if they are repeated, have to be shown again.

The heat pump 100 according to the invention is described in conjunction with the attached Figures 1 to 19, with individual aspects of the heat pump according to the invention being viewed with different facets in the various Figures 1 to 19 in order to highlight the individual aspects of the embodiments of the heat pump according to the invention in synopsis. The individual aspects of the embodiments can be interchanged with one another as desired.

1 shows a hydraulic diagram of the heat pump 100 according to the invention. In the hydraulic diagram according to FIG. 1, a first compressor stage 10 and a second compressor stage 20 can be seen. The first compressor stage 10 and the second compressor stage 20 are connected to one another via a steam channel 30. The steam channel preferably has a curved shape with a depression 32. Mathematically speaking, the steam channel has at least one turning point in the depression 32, with a curvature being zero in the at least one turning point. According to the hydraulic diagram according to FIG. 1, an intercooler 40 is arranged in the depression 32. The intercooler 40 includes an operating element 42 and an intercooler sump 44. The intercooler sump 44 for collecting fluid and the operating element 42 of the intercooler 40 are coupled to one another via a first intercooler line 46, with fluid from the intercooler sump 44 via the first intercooler line 46 can be guided to the effect element 42 in order to sprinkle compressed fluid from the first compressor stage 10, which is led in particular in the steam channel 30 to the second compressor stage 20, for the purpose of cooling. Furthermore, starting from the intercooler sump 44, a second intercooler line 48 is provided. The second intercooler line 48 leads from the intercooler sump 44 to a ball bearing adapter 49 for cooling the ball bearing adapter 49.

1 further shows an evaporator 50 assigned to the first compressor stage 10. The evaporator 50 comprises an evaporator sump 52. Above the evaporator sump 52, the evaporator 50 comprises an upper evaporator part 54, in which the first compressor stage 10 is arranged. In the evaporator 50, a pipe 56 is arranged above the evaporator sump 52, which is arranged in a matrix shape above the evaporator sump 52 according to the cross section shown in the hydraulic diagram according to FIG. The pipeline 56 above the Fluid to be cooled can flow through the evaporator sump 52. A sprinkler device 58 is arranged above the pipeline in order to irrigate the pipeline 56 with fluid from the evaporator sump 52. From the evaporator sump 52 to the sprinkling device 58, a first evaporator line 59 is provided, which directs fluid from the evaporator sump 52 to the sprinkling device 58. After the pipe 56 has been irrigated, the fluid released via the sprinkling device 58 can be collected in the evaporator sump 52 and fed again to a circuit of the heat pump 100.

1 also shows a bridging channel 62 between the first compressor stage 10 and a condenser 60 for bridging the second compressor stage 20. Via the bridging channel 62, compressed fluid can be passed directly to the condenser 60 after exiting the first compressor stage 10. The condenser 60 includes a condenser sump 64 for collecting fluid. A pipeline 56 is arranged above the condenser sump 64. However, the pipe 56 assigned to the condenser does not have a sprinkling device. The pipe 56 assigned to the condenser 60 is flowed through by fluid to be heated.

Further features of the hydraulic scheme according to FIG. 1 will be described below in connection with the further advantageous embodiments of the heat pump 100.

Fig. 2 shows an enlarged section of the hydraulic diagram according to Fig. 1, with a cross-sectional reduction element 70 (upper strand) and a steam transfer flap 90 (lower strand) being shown. When the steam transfer flap 90 is open, vaporous fluid can be guided from the condenser 60 into the evaporator 50 via a steam guide line 92. In an open state of the cross-sectional reduction element 70, vaporous fluid can be conducted directly to the condenser 60 via the bridging channel 62.

According to a preferred embodiment, the heat pump 100 includes the evaporator 50 for evaporating a fluid to obtain a vaporized fluid, the evaporator 50 having the evaporator sump 52. Furthermore, the heat pump 100 includes the condenser 60 to evaporate and from an N-stage Compressor 10, 80, 20 to condense compressed fluid, the condenser 60 having a condenser sump 64, a condensation area 66 and a holding area 67 for holding any vaporous fluid remaining after the condensation area 66. The N-stage compressor 10, 20, 80 includes N compressors, where N is a natural number greater than or equal to one, the N-stage compressor 10, 20, 80 being arranged between the evaporator 50 and the condenser 60. In addition, the heat pump 100 includes the steam channel 30, which couples at least two of the N compressors of the N-stage compressor 10, 20, 80 between the evaporator 50 and the condenser 60. In Fig. 4, for example, an N-stage compressor, 10, 20, 80 is shown, in which N = 3. Furthermore, the heat pump 100 includes a vapor guide line 92, which is arranged between the condenser 60 and the evaporator 50 in order to guide vaporous fluid from the holding area 67 of the condenser 60 into the evaporator 50. Figs. 2 and 4 show, for example, a single steam guide line 92, in which the steam transfer flap 90 is arranged.

Fig. 3 shows a schematic test stand which is used to test the functionality of a single compressor of the heat pump 100 under real operating conditions. According to the test bench 300 from FIG. 3, N=1. The test stand 300 includes a compressor 301 to be tested and at least one pressure sensor 302 for measuring a compression pressure of the compressed fluid. In addition, the test stand 300 includes at least one temperature sensor 303 for measuring the temperature of the compressed fluid. The at least one pressure sensor 302 and the at least one temperature sensor 303 are arranged near the compressor 301 to be tested. A fluid line 15 and a fluid line 15 lead into the test stand 303 in order to supply fluid, in particular cooling water, to or from the pipeline 56. The flow in the fluid lines 15 is regulated depending on a liquefaction pressure. The fluid lines 15 of the test stand 300 are preferably connected to a cold water ring line (at a water temperature of approximately 17° degrees). The test stand 300 includes a Jacob tube which includes a K4 condenser. The Jacob tube preferably has a height of up to 650 mm, in particular 600 mm, and a diameter of up to 600 mm, in particular 500 mm or 550 mm. The test stand also includes another Jacob tube, which has a height of up to 300 mm, in particular 240 mm, and a diameter of up to 600 mm, in particular 500 mm or 550 mm. The Jacob tubes are arranged on a container 45 in which the fluid occupies a fluid level 51. In the container 45 is a temperature sensor 303 for measuring a sump temperature is arranged in the container 45. At least one packing body 7 is arranged above the fluid level 51. The packing 7 preferably comprises several individual packings, which are intended to allow the steam to flow past a larger surface so that it condenses out in a particularly advantageous manner. The fluid level 51 is set in the container 45 in such a way that there is a distance between the liquid fluid and the tube wall in a pipe 306, which supplies the fluid to the container 45. This distance creates a steam flow 304 between the water level and the pipe wall. The pipe 306 provides a connection between an outlet of the compressor under test 301 and an inlet to the container 45 to return vaporized fluid from the compressor under test 301 to the container 45. The pipe 306 is in particular designed in two parts, with a throttle valve 307 being arranged between the two pipe sections in order to adjust a resistance of the evaporated fluid. Furthermore, the evaporation temperature is set using the throttle valve 307. A connection 311 of the tube 306 to the compressor 301 to be tested is designed such that different cross sections of different compressors 301 can be connected to the tube 306. The test stand 300 also has a geometric structure which serves as a return line 308 of the condensed fluid from the compressor 301 to be tested. An effective element 43 for sprinkling the evaporated fluids is also provided in the pipe 306. By means of a pump 310 and an associated line, fluid is pumped from the container 45 into the operating element 42 of the test stand 300. The test bench further includes a sensor 309, which is in particular a volume flow sensor to measure a volume flow of the evaporated fluid. A connected control device receives the measurement signals from the volume flow sensor and, among other things, determines the control signal from this signal in order to specify its target speed to the compressor.

The holding area 67 is preferably arranged in the condenser 60 between the condensation area 66 and the condenser sump 64 with condensed working fluid. An opening 65 of the steam guide line 92 is arranged in the holding area 67 above a fill level 68, in particular a fluid level (51), of the working fluid in the condenser sump 64. The opening 65 of the steam guide line 92 comprises a channel piece which protrudes through the condenser sump 64 into the holding area 67 in order to conduct evaporated, i.e. non-condensed, fluid via the steam guide line 92 to the evaporator 50. The condenser sump 64 with condensed working fluid is preferably arranged in the condenser 60. The steam guide line 92 extends from the holding area 67 through the condenser sump 64 and is led out of the condenser through a wall, preferably a floor, of the condenser 60. In Figs. 2 and 4, for example, it is shown how the steam guide line 92 extends through a bottom of the condenser sump 64. It is conceivable that the steam guide line 92 extends through a wall, in particular a side wall, through the condenser sump 64.

The condenser 60 preferably has a tube bundle 56a or a spiral-shaped tube arrangement 56b, through which liquid to be heated can flow, the tube bundle 56a or the spiral-shaped tube arrangement 56b being arranged laterally with respect to the opening 65 of the steam guide line 92, and above of the tube bundle 56a or the spiral tube arrangement 56b, an intake port 12 of a compressor of the N-stage compressor 10, 20, 80 is arranged. The tube bundle 56a or the spiral tube arrangement 56b are also referred to here as a pipeline 56.

The steam guide line 92 preferably has an opening 55 in the evaporator 50, the opening 65 being arranged above the evaporator sump 52 in the evaporator 50. The steam guide line 92 thus has two openings 55, 65, one opening leading through the condenser sump 64 and the other opening 55 opening into the evaporator 50 above the evaporator sump 52. This is shown, for example, in Figs. 2 and 4 can be found.

Preferably, a tube bundle 56a for liquid to be cooled and a sprinkling device 58 for sprinkling the tube bundle 56a are arranged in the evaporator 50, the opening 55 of the vapor guide line into the evaporator 50 being arranged in such a way that vaporous fluid passes through the opening 55 into the evaporator 50 arrives, hits the tube bundle 56a laterally, and/or that the vaporous fluid that emerges from the steam guide line 92 enters a sprinkling area 57, which is at least partially sprinkled by the sprinkling device 58. Such as Figs. 1, 2 or 4, the sprinkler device 58 is supplied with fluid from the evaporator sump 52 via a first evaporator line 59 between the evaporator sump 52 up to the sprinkler device 58. After Sprinkling the tube bundle 56a in the evaporator 50, the fluid used for sprinkling can be collected again by the evaporator sump 52 and fed again to a circuit of the heat pump 100.

Each compressor of the N-stage compressor 10, 20, 80 preferably has its own shaft, on which the corresponding compressor of the N-stage compressor 10, 20, 80 can be operated and individually controlled during operation. As shown in Figs. 1, 2 or 4, for example, each compressor has its own motor M. The compressors of the N-stage compressor 10, 20, 80 can therefore be operated independently of one another or not be operated individually.

Preferably, the N-stage compressor 10, 20, 80 N comprises compressors connected in series, with the vapor guide line 92 being formed as a single vapor guide line 92 and the vaporous fluid, which has been brought into the condenser 60 from a final stage, from the condenser 60 leads into the evaporator 50 (see Figs. 2, 4 and 5). A hydraulic diagram of the N-stage compression is shown in FIG. In Fig. 5, for example, the cross-sectional reduction element 70 is shown designed as a valve. The N-stage compressor 10, 20, 80 is shown as an N series-connected compressor, which is connected between the evaporator 50 and the condenser 60.

Preferably, at least two compressors of the N-stage compressor 10, 20, 80 are connected via a vapor channel 30 and an intercooler 40 is arranged between two compressors in order to cool the vaporous fluid (see FIG. 4). Each intercooler 40 includes an effect element 42 and an intercooler sump 44 (see FIG. 4). The intercooler sump 44 is each for collecting fluid and the effect element 42 of the respective intercooler 40 is each coupled to one another via a first intercooler line 46, wherein fluid from the intercooler sump 44 can be guided to the effect element 42 via the first intercooler line 46. After passing through the respective effective element 42, the fluid can be collected by the intercooler sump 44. The fluid can then be fed back into a circuit of the heat pump 100. In Fig. 5, for the sake of clarity, an intercooler 40 is not shown between the compressors of the N-stage compressor 10, 20, 80. The intercooler 40 is preferably arranged in a depression 32 of the steam channel 32 and the intercooler 40 has an intercooling sump 44 and an effect element 42, the effect element 42 being designed to ensure an interaction between an intercooling fluid that flows through a supply line, in particular the first intercooler -Line 46, from the intermediate cooling sump 44 or from the evaporator sump 52 or from the condenser sump 64 can flow into the effect element 42, and a heated vaporous fluid that can be emitted by the compressor, the interaction in particular cooling the vaporous fluid emitted by the compressor caused by the intercooling fluid (see Figs. 2 and 4). Before the vaporous fluid is sucked into the vapor channel 30 by the second compressor stage 20, the vaporous fluid is cooled by the intercooler 40.

Each intercooler 40 preferably has an intercooling sump 44 and an effective element 42 and is arranged in its own depression 32 in the steam channel 30, in particular each intercooler 40 has its own first intercooler line 46 to the effective element 42. The first intercooler line 46 can also be referred to as a supply line. In particular, in the case of several intercooling sumps 44, the supply lines, i.e. the first intercooler lines 46, can also be connected to one another (not shown in the figures), so that the supply lines then only form a total of one supply line.

The steam channel 30 between two compressors preferably has a curved shape with the depression 32, so that fluid from the steam channel 30 flows past the intermediate cooling sump 44. Condensing fluid can be collected in the intercooling sump 44.

The steam guide line 92 and the steam channel 30 are preferably fluidly separated from one another. In the present case, fluidly separated from one another means that the steam guide line 92 and the steam channel 30 are not brought together into one another, which would allow the fluid to mix. Therefore, the steam guide line 92 and the steam channel 30 are shown in FIGS. 2 and 4, for example, are drawn with dashed lines to show that the steam guide line 92 and the steam channel 30 are separated from one another. Mind you, they form Steam guide line 92 and the steam channel 30 form a circuit in which the fluid in the heat pump 100 circulates. The steam channel 30 or the steam channels 30 is/are arranged between the evaporator 50 and the condenser 60 in the upper strand. The steam guide line 92 is arranged between the evaporator 50 and the condenser 60 in the lower branch.

Preferably, further N compressors are arranged in such a way that a further compressor of the N compressors is connected in series to a first compressor of the N-stage compressor 10, 20, 80 by switching a switch into an open state. In Fig. 5, n+1 compressors to the first compressor 10 are schematically sketched. The n+1 compressor is drawn with dashed lines, which is intended to indicate the switching on of the individual compressors of the N-stage compressor 10, 20, 80. In the present case, the first compressor stage 10 includes the first compressor. The second compressor stage includes the second compressor. An nth compressor stage includes an nth compressor, where n is a natural number.

A bridging flap 90 is preferably arranged in the vapor guide line 92, which can be converted to an open position, an intermediate position or, to avoid the vaporous fluid being guided into the evaporator, into a closed position to guide the vaporous fluid from the condenser 60 to the evaporator 50 is. Similar to the cross-sectional reduction element 70, the bridging flap 90 can be designed as a panel or a wing door or a check valve or as a valve, as shown, for example, in FIG. 5. The heat pump 100 further includes a controller for controlling the bypass flap 90 into the open position, into the intermediate position or into the closed position.

The bridging flap 90 is preferably designed as a controlled bridging valve, which can be addressed by means of the control in order to be operated near a boundary line of a compressor map 170 assigned to the N-stage compressor 10, 20, 80. The design of the bridging flap 90 as a controlled bridging valve is shown, for example, in FIG. 5. The bridging flap 90 can also be referred to here as a steam transfer flap 90. A compressor map 170 associated with the N-stage compressor 10, 20, 80 defines a relationship between a pressure ratio and a mass flow. Such a compressor map 170 is shown, for example, in FIG. 15. The compressor map 170 is to be understood as a three-dimensional field, the third dimension being represented by shading in the two-dimensional coordinate system, which is spanned by the pressure ratio PiC and the, in particular corrected, mass flow WcCorr. The pressure ratio PiC describes a ratio of the pressures between the evaporator 50 and the condenser 60, ie between the compressor stages 10, 20, 80. A surge limit 171 is present in the compressor map 170, which represents a monotonically increasing function between the mass flow and the pressure ratio. The bypass flap 90 is controlled to ensure that for a specific mass flow, the pressure ratio is less than a limit pressure ratio that is assigned according to the function to the specific mass flow. In Fig. 15, the dotted lines show 172 lines of the same speed at a measured evaporation temperature of 18° degrees.

The control is preferably designed to move the bridging flap 90 into a closed position, into an open position, or into an intermediate position in order to reduce the load of the N-stage compressor 10, 20, 80 to at least a load setpoint during operation hold. The surge limit 171 can in particular describe the load setpoint, which in particular can also be a function depending on the mass flow WcCorr. In particular, the control is designed to control the bridging flap 90 in such a way that the heat pump 100 is operated essentially along the surge limit 171 or in an area that is slightly shifted to larger mass flows WcCorr, so that operation of the compressor below its absorption limit is advantageously prevented is.

The control is preferably designed to open the bridging flap 90 when the load of the N-stage compressor 10, 20, 80 falls below the load setpoint; or close the bypass damper 90 when the load of the N-stage compressor 10, 20, 80 exceeds the load setpoint to generate additional load; or to control the intermediate position of the bridging flap 90 depending on whether the load setpoint is undershot. This can ensure that the heat pump is operated essentially along the surge limit 171. For example, the bridging flap 90 can be moved to the intermediate position when the load of the N-stage compressor 10, 20, 80 deviates from the load setpoint by up to 5%. This can be done starting from the open or closed position of the bridging flap 90. The load setpoint indicates a load of the heat pump 100 during operation, which can be achieved at least by the N-stage compressor 10, 20, 80.

Preferably, in the case of a two-stage compressor 10, 20, as shown for example in FIG except a first stage 10 are switched off when the bridging flap 90 is opened. As soon as all but one of the compressor stages are switched off, the bridging flap 90 is opened. If at least one further compressor stage is switched on in addition to the one compressor stage that is already in operation, the bridging flap 90 is closed or, if necessary, transferred to an intermediate position. For example, the first compressor 10 can be controlled depending on a speed of a compressor drive in order to adapt the speed of the first compressor stage 10 to a required performance of the first compressor 10.

Fig. 6 shows a three-dimensional view of the heat pump 100 according to the invention. The heat pump 100 includes the first compressor stage 10 and the second compressor stage 20. The first compressor stage 10 and the second compressor stage 20 are connected to one another via the curved steam channel 30, the steam channel 30 being the intercooler 40 has. Furthermore, the view from Fig. 6 shows that the first compressor stage 10 is connected to the condenser 60 via the bridging channel 62, the cross-sectional reduction element 70 being arranged in the bridging channel 62. The heat pump 100 has already been described with reference to FIG. 1. According to the view of FIG. 6, not all details can be seen, which, for example, the hydraulic diagram according to FIG. 1 reveals. However, the proportions can be seen from the heat pump 100 shown in FIG. 6; for example, the steam channel 30 has an average diameter that corresponds approximately to half the width of the condenser. In this respect, for the description of FIG. 6, reference is also made to the description of FIG. 1 or another figure, which shows a hydraulic diagram of the heat pump 100 according to the invention.

A preferred embodiment of the heat pump 100 includes an evaporator

50 for vaporizing a fluid to obtain vaporized fluid. Furthermore, it includes Heat pump 100 a condenser 60 for condensing a compressed fluid. In addition, the heat pump 100 includes a compressor with a first compressor stage 10 and a second compressor stage 20, wherein the compressor is arranged in the flow direction of the evaporated fluid during operation of the heat pump 100 between the evaporator 50 and the condenser 60 and is designed to transport the evaporated fluid to compress to obtain compressed fluid. According to the proposal, a bridging channel 62 is arranged between the first compressor stage 10 and the condenser 60 in order to bridge the second compressor stage 20, wherein a cross-section reducing element 70 is arranged in the bridging channel 62 in order to adjust a cross section of the bridging channel 62 in order to ensure a flow of compressed fluid the first compressor stage 10 to the condenser 60 to regulate. After exiting the first compressor stage 100, compressed fluid can thus be passed directly to the condenser 60, provided that the cross-sectional reduction element 70 assumes an open position. In particular, when the second compressor stage 20 is not in operation, ie it is in a switched-off state, the cross-sectional reduction element 70 is in the open position.

The first compressor stage 10 and the second compressor stage 20 are preferably connected via the steam channel 30 (see also the description of FIG. 1). The steam channel 30 is curved, in particular banana-shaped, i.e. curved. The steam channel 30 can have a depression 32 in which a container 45, also called an intercooler sump 44, is arranged to collect fluid that passes through the steam channel 30, provided that the gaseous fluid passing through the steam channel 30 condenses. Because the container 45 is arranged in the depression 32, condensed fluid can be fed into the container 45 automatically, in particular without any further technical means, by utilizing the gravitational force.

Preferably, the bridging channel 62 has an opening in the first compressor stage 10, wherein the first compressor stage 10 has a suction port 12 for sucking in the evaporated fluid and a guide space 14 in order to direct the vaporous compressed fluid into the bridging channel 62. The intake port 12 can be cone-shaped, with a first diameter being arranged in a suction region of the intake port 12 for sucking in the fluid and a second diameter of the intake port 12 directly adjoining the guide space 14. In particular, the first diameter is larger than the second diameter. In the present case, the first diameter is a maximum diameter 16 and the second Diameter is a minimum diameter 17. The guide space 14 is arranged transversely, in particular substantially orthogonally, to the second diameter of the intake port 12.

The condenser 60 preferably has a pipeline 56. The pipeline 56 is preferably designed as a tube bundle 56a or a spiral-shaped tube arrangement 56b, through which liquid to be heated can flow, the tube bundle 56a or the spiral-shaped tube arrangement 56b being arranged laterally with respect to a further opening of the bridging channel 62, and where An intake port 12 of a compressor of the second compressor stage 20 is arranged above the tube bundle 56a or the spiral tube arrangement 56b.

Preferably, the further opening of the bridging channel 62 is arranged such that vaporous fluid, which passes through the further opening into the condenser 60, hits the tube bundle 56 laterally. Because the pipe 56, i.e. the pipe bundle 56a or the spiral pipe arrangement 56b, is arranged laterally with respect to a further opening of the bridging channel 62 in the condenser 60, evaporated compressed fluid, after passing through the bridging channel 62, hits directly from the pipe 56 on which the evaporated fluid and compressed fluid can be cooled. Because the fluid to be heated can flow through the pipeline 56, heat is transferred from the evaporated and compressed fluid, which hits the pipeline 56 laterally from the bridging channel 62, via the pipeline 56 to the fluid to be heated flowing through the pipeline. When the evaporated and compressed fluid hits the pipeline 56, the evaporated and compressed fluid is cooled so that condensation can occur. A fluid condensed on the pipeline 56 can drip into the condenser sump 64, in particular due to gravity.

Preferably, the cross-sectional reducing element 70 is designed to assume a closed position or an open position depending on the operation of the second compressor stage 20, wherein the cross-sectional reducing element 70 is designed to assume the closed position when the second compressor stage 20 is switched on, or the open position to be taken when the second compressor stage 20 is switched off. Depending on the operation of the second compressor stage 20, the cross-sectional reduction element 70 can be in the closed or be transferred to the open position. It is also conceivable to transfer the cross-sectional reduction element 70 to an intermediate position, i.e. a position between the open and the closed position, in particular when the second compressor stage 20 is shut down (switched off) or started up (switched on).

Preferably, the cross-sectional reduction element 70 is biased in the closed position by means of a spring element (not shown). If the second compressor stage 20 is switched off, the prestressed spring element can relax, in particular due to the absence of suction of compressed fluid from the first compressor stage 10 through the steam channel 30, so that the cross-sectional reduction element 70 transitions into the open position. The compressed fluid from the first compressor stage 10 can then pass through the bridging channel 62, whereby the second compressor stage 20 is bridged.

Preferably, the cross-sectional reduction element 70 is a flap or a panel or a wing door or a non-return flap. 7 shows a top view of the cross-sectional reduction element 70 in FIG. 7a and a side view of the cross-sectional reduction element 70 in FIG Fig. 1, Fig. 2 or Fig. 4). A diameter 72 of the cross-sectional reduction element 70 (as shown in FIG. 7a) may correspond to a diameter of the bridging channel 62 or be smaller than the diameter of the bridging channel 62. The diameter of the bridging channel 62 can be 10mm, for example. Of course, the diameter of the bridging channel 62 can also have a different diameter. In the side view of the cross-sectional reduction element 70 (as shown in FIG. 7b), the diameter 72 of the cross-sectional reduction element 70 is smaller than the diameter of the bridging channel 62. Fig. 7c shows a detail from Fig. 7b with regard to a connection of the cross-sectional reduction element 70 for controlling the cross-sectional reduction element 70 into the open or closed position. Further requirements of the cross-sectional reducing element 70 can be found, for example, in DIN EN ISO 5211.

The heat pump 100 preferably has a controller for controlling the

Cross-section reducing element 70 in the open position or the closed position position. Depending on the design of the cross-sectional reducing element 70 as a flap or panel or wing door or non-return flap, the control is designed to control the flap or panel or wing door or non-return flap. When designed as a diaphragm, for example, the control is designed to increase or decrease a diameter of the diaphragm.

Preferably, the first compressor stage 10 is designed to build up a maximum affordable pressure, and the cross-sectional reduction element 70 is designed to assume the open position when a pressure ratio between the condenser pressure Tl ₂ and the evaporator pressure Th is smaller than the maximum affordable pressure of the first compressor stage to convey compressed fluid from the first compressor stage 10 to the condenser 60 via the bypass channel 62. The pressure ratio between the condenser pressure Tl ₂ and the evaporator pressure T can be calculated, for example, by measuring temperatures. In particular, the temperature Th in the evaporator sump 52 and the temperature Tl ₂ in the condenser sump 64 can each be measured in order to determine the pressure ratio between the condenser pressure (Tl ₂ ) and the evaporator pressure Th. In the present case, the measured temperature Th in the evaporator sump 52 is associated with the evaporator pressure Th. In the present case, the measured temperature Tl ₂ in the condenser sump 64 is also associated with the condenser pressure Tl ₂ . Therefore, the corresponding measured temperature reference symbols Th and Tl ₂ are used as reference symbols for the respective pressure in the condenser sump 64 or in the evaporator sump 52. For example, Fig. 18 shows where the temperatures Th, TL are measured.

Preferably, the cross-sectional reduction element 70 is designed to assume the closed position when the pressure ratio between the condenser pressure Tl ₂ and the evaporator pressure Th is greater than the maximum achievable pressure of the first compressor stage 10 in order to supply compressed fluid from the first compressor stage 10 via the steam channel 30 the second compressor stage 20 to lead. Once in the second compressor stage 20, the compressed fluid is further compressed before it is fed to the condenser 60 via a guide space 14. The guide space 14, which is assigned to the condenser 60, is designed analogously to the guide space 14, which is assigned to the evaporator 50 in the upper evaporator upper part 54. Preferably, the first compressor stage 10 can be operated with N further compressor stages, where N is a natural number greater than or equal to two. In Fig. 4, for example, three compressor stages 10, 20, 80 are shown. As shown in FIG. 4, N here is equal to three. It is conceivable to provide any number of compressor stages between the evaporator 50 and the condenser 60. The first compressor stage 10 and the N further compressor stages 80, 30 are preferably arranged in a series connection, with N compressor stages two adjacent compressor stages each being connected via a steam channel 30 (see Fig. 4, where N = 3 is shown, or Fig .5).

Fig. 8 shows a hydraulic diagram according to Fig. 1, in which a circuit of indirect intermediate cooling 8 is shown. The indirect intermediate cooling 8 is used in a preferred embodiment of the heat pump 100.

In the preferred embodiment of the heat pump 100, as shown in FIG. 8, the heat pump 100 includes the evaporator 50 for evaporating a fluid to obtain a vaporized fluid, the evaporator 50 having the evaporator sump 52. Furthermore, the heat pump 100 includes the condenser 60 for condensing a compressed fluid, the condenser 60 having the condenser sump 64. The heat pump 100 further has the compressor with the first compressor stage 10 and the second compressor stage 20, wherein the compressor is arranged in the flow direction of the evaporated fluid during operation of the heat pump 100 between the evaporator 50 and the condenser 60 and is designed to transport the evaporated fluid Compress fluid to obtain the compressed fluid. The heat pump, as shown in Fig. 8, further includes a container 45 for collecting an intercooling fluid. In particular, the container 45 is an intermediate cooling sump 44. The heat pump further comprises a heat exchanger 82 with a pipe 56 which is designed to be flowed through by the intermediate cooling fluid from the container 45, the pipe 56 being in a flow region 11 between the first compressor stage 10 and the second compressor stage 20 is arranged to cool vaporous fluid in the flow region 11. 8 shows, for example, that the heat exchanger 82 is arranged around an intake port 12 of the first compressor stage 10. In other words, according to the embodiment according to FIG. 8, the pipeline 56 is arranged in the area of the first compressor stage 10. As shown in Fig. 14, the heat exchanger 82 can be arranged for indirect cooling between the first compressor stage 10 and the second compressor stage 20, in particular where an intercooler 40 and/or another intercooler 4 and/or yet another intercooler 5 can be provided.

The pipeline 56 is preferably metallic, preferably the pipeline 56 has stainless steel and/or copper. The metallic pipe 56 improves heat transfer between fluid within the pipe 56 and fluid outside the pipe 56.

The pipeline 56 of the heat exchanger 82 is shown, for example, in Figs. 8 to 10 shown. Preferably, the pipe 56 of the heat exchanger 82 has an area in which the pipe 56 runs in a spiral or spring-shaped manner, the spring-shaped or spiral-shaped area having turns 83 with different turn spacings. In the case of a spring-shaped pipeline 56, the diameter from one turn to the next is constant. In the case of a spiral-shaped pipeline 56, the diameter of one turn is different in size from the diameter of a subsequent turn. A spiral-shaped pipeline 56 can be designed as a conical spiral. A spring-shaped pipeline 56 is created when a helical line 101 is centrally projected onto a plane perpendicular to the screw axis 102, as shown, for example, in FIG. 10. Fig. 10 schematically branches off the heat exchanger 82.

The first compressor stage 10 preferably has a suction port 12 for sucking in the evaporated fluid and a guide space 14 in order to direct the vaporous fluid into the flow region 11. The flow area 11 includes a volume of an upper evaporator part 54, the steam channel 30 and the bridging channel 62. The flow area 11 includes those areas of the heat pump 100 into which evaporated and compressed fluid can flow.

As for example in Figs. 8 and 9, the pipeline 56 of the heat exchanger 82 is arranged around the intake port 12 of the first compressor stage 10, with a turn spacing between two turns 83 in an inflow area of the vaporous fluid of the first compressor stage 10 being greater than in an outflow area of the vaporous fluid the guide space 14. This is shown, for example, in Figs. 8 and 9 can be seen. Because the distance between two turns 83 in an inflow area is larger, the flow speed of the steam is slowed down slightly. By In the outflow area of the vaporous fluid into the guide space 14, the winding distance between two turns 83 is larger in order to improve, in particular to increase, cooling of the steam.

Fig. 11 shows, for example, a diametrical perspective view of the heat exchanger 82. Fig. 11 shows that it is also conceivable that in the outflow area of the vaporous fluid out of the guide space 14 the winding distance between two turns 83 is smaller than in that Inflow area.

Preferably, a steam channel 30 is arranged between the pipeline 56 and the container 45, with the outflow region 11, in particular also referred to as the flow region 11, being connected to the steam channel 30 in order to convey the vaporous fluid via the steam channel 30 through the container 45 to pass through, “to pass through the container 45” is to be understood as “to pass over the container 45”. The vaporous fluid is attracted by the second compressor during operation of the second compressor stage 20. As a result, the vaporous fluid is passed through the vapor channel 30, as can be seen, for example, in FIG. 8.

A fluid line channel 15 preferably extends from the outflow area 11 laterally into the steam channel 30 in order to supply the intermediate cooling fluid flowing through the heat exchanger 82 to the container 45 via the steam channel 30 (see FIG. 8). The outflow area 11 extends from an outlet of the first compressor stage into the steam channel 30 and into the evaporator part 54. The fluid line channel 15 extends through a wall, in particular a floor, of the upper evaporator part 54. This collects in a floor area of the upper evaporator part 54 Intercooling fluid flowing through heat exchanger 82 and forms a fluid level 51. If the fluid level 51 of the upper evaporator part 54 is above the extent of the fluid line channel 15 through the wall, the intermediate cooling fluid can flow into the vapor channel 30 via the fluid line channel 15, in particular due to gravity.

The intake port 12 preferably has a funnel shape which has a maximum diameter 16 and a minimum diameter 17 opposite one another, with the guide space 14 for guiding the compressed vaporous fluid running axially to the minimum diameter 17 of the funnel shape. The maximum diameter 16 can adjoin the bottom of the upper evaporator part 54, whereby the intermediate cooling fluid flowing through the heat exchanger 82 is collected outside the intake port 12 of the first compressor stage 10 in the bottom area (see FIG. 8).

The guide space 14 is preferably curved at one end, which merges into the upper evaporator part 54, in order to direct the vaporous fluid flowing through the guide space 14 in a direction opposite to a gas flow direction in the intake port. In particular, the vaporous fluid leaving the guide space 14 is directed into the vapor channel 30, if the second compressor stage is in operation, or into the vapor guide line 92, if the second compressor stage is not in operation.

The guide space 14 preferably has a volume with a circle or an oval as a base area. The guide space 14 is arranged essentially perpendicular to the minimum diameter 16 of the intake port 12 of the first compressor stage 10. The guide space is arranged in particular in the upper evaporator part 54. Furthermore, the second compressor stage 20 also has a guide space 14, which is arranged essentially perpendicular to the minimum diameter 16 of the intake port 12 of the second compressor stage 20. The guide space 14 of the first or second compressor stage 10, 20 can also have another base area of any design.

A further heat exchanger 82 is preferably arranged in the steam channel 30 at a distance from the outflow area 11. The further heat exchanger 82 is preferably arranged in an intake port 12 of the second compressor stage 20. The first and second compressor stages 10, 20 are connected by the steam channel 30, the steam channel 30 being arranged between a pressure side of the first compressor stage 10 and a suction side of the second compressor stage 20. Preferably, the steam channel 30 has a curved shape with a depression 32. Preferably, the container 45 is arranged in the depression 32 so that liquid intercooling fluid flows from the vapor channel 30 into the container 45. This can be seen in FIG. 8, for example.

The heat exchanger 82 and/or the further heat exchanger preferably has/have

82 has an at least partially contoured outer surface on its outer surface, which is in contact with the vaporous fluid in order to improve heat transfer between the heat transfer medium 82 and the vaporous fluid. Preferably, the heat exchanger 82 and/or the further heat exchanger 82 has an at least partially contoured inner surface on its inner surface, which is in contact with the fluid from the container 45 in order to cause the formation of a turbulent flow on its inner surface. The contoured inner and/or outer surfaces can have grooves and/or reliefs, ie recesses/projections of any shape.

For self-regulation of a fluid level, the condenser sump 64 and/or the evaporator sump 52 and/or the container 45 are preferably each connected to one another in a fluid-conducting manner via a fluid line channel 15, so that the fluid level 51 of the individual sumps 52, 45, 64, in particular only below Utilization of gravity is regulated. In other words, the fluid level 51 of the individual sumps 52, 45, 64 is set passively due to the geometric arrangement and the connection of the individual sumps 52, 45, 64 to one another (see, for example, Figs. 1, 2, 8, or 12 to 14 ). In this case, self-regulation means passive regulation, i.e. without further technical means. However, it is conceivable to also provide active regulation of the fluid level of the sumps 52, 45, 64 by pumping, in which, for example, a control can be provided as well as level sensors which detect the level in the sumps 52, 45, 64.

Preferably, a return line 2, which is also referred to in particular as a fluid line channel 15, extends for conducting fluid from the condenser sump 64 from the condenser sump 64 into the container 45 or the intermediate cooling sump 44. Furthermore, a fluid line channel 15 preferably extends for conducting fluid the container 45 or the intermediate cooling sump 44 from the container 45 or the intermediate cooling sump 44 into the evaporator sump 52, in particular the fluid line channel 15 starting from a bottom of the container 45 or or the intermediate cooling sump 44 laterally into the evaporator sump 52 below the fluid level 51 of the evaporator sump 52 extends into it. The container 45 is preferably an intercooling sump 44 of an intercooler 40.

The heat pump 100 preferably has an intercooling circulation pump 22

Supply intermediate cooling fluid from the container 45 to the pipeline 56. The intermediate cooling fluid supply line 3 can be in this embodiment Heat pump 100 extends from the container 45 to the pipeline 56 (see Fig. 8). In the embodiments of FIGS. 12, 13 and 14, the intercooling circulation pump 22 can supply intercooling fluid from the evaporator sump 52 to the pipeline 56.

Fig. 9 shows a hydraulic diagram of the indirect intermediate cooling 8 with indirect heat exchanger 82. From Fig. 9 it can be seen in a simplified representation that from the upper evaporator part 54, in which in particular the first compressor of the first compressor stage 10 is arranged and in which the Heat exchanger 82 can be arranged, the steam channel 30 extends to the second compressor stage 20. Compressed fluid coming out of the first compressor stage 10 can therefore be guided to the second compressor stage 20 via the steam channel 30. Furthermore, starting from the arranged heat exchanger 82, one of the fluid line channels 15 extends, in which the fluid flowing through the heat exchanger 82 can be guided into the container 45. The legend of Fig. 9 further shows that the fluid line channels 15 and the intermediate cooling fluid supply line 3 conduct liquid fluid, i.e. in this case water. It can also be seen that the steam channel 30 between the first and second compressor stages 10, 20 is an active steam path. In the present case, active steam path means that the second compressor stage 20 is in operation, so that compressed fluid leaving the first compressor stage is sucked in through the second compressor stage 20. The bridging channel 62 between the first compressor stage and the condenser 60, however, is an inactive vapor path. In the present case, inactive vapor path means that the second compressor stage 20 is out of operation and the cross-sectional reduction element 70 is open, so that compressed fluid that leaves the first compressor stage is fed directly into the condenser 60 via the bridging channel 62.

According to a further preferred embodiment, the heat pump 100 includes the evaporator 50 for evaporating a fluid to obtain a vaporized fluid, the evaporator 50 having the evaporator sump 52. Furthermore, the heat pump 100 includes the compressor with the first compressor stage 10 and the second compressor stage 20, wherein the compressor is arranged in the flow direction of the evaporated fluid during operation of the heat pump 100 between the evaporator 50 and the condenser 60 and is designed to transport the evaporated fluid to compress to obtain compressed fluid. The condenser 60 serves to condense the compressed fluid. The heat pump 100 also includes the intercooler 40, which is connected to an intercooling fluid supply line 3 and has the operating element 42, wherein the operating element is arranged between the first compressor stage 10 and the second compressor stage 20 and is designed to ensure an interaction between an intercooling fluid that can be supplied through the intercooling fluid supply line 3, and one of to cause the heated vaporous fluid that can be output from the first compressor stage 10. The intermediate cooling fluid supply line 3 extends from the evaporator sump 52 to the operating element 42. Such a preferred embodiment of the heat pump is shown as a hydraulic diagram, for example in FIG. 12. Fig. 12 also shows the hydraulic diagram, which shows a supply of the intermediate cooling, the intermediate cooling being fed from the evaporator sump 52. Fluid from the evaporator sump 52 is supplied to the effect element 42 via the intercooling fluid supply line 3, so that the fluid from the evaporator sump 52 can be used to sprinkle evaporated and compressed fluid, which passes through the intercooler 40, which is arranged in the vapor channel 30.

Preferably, the intercooling fluid supply line 3 extends through an opening in the evaporator sump 52, and the opening of the intercooling fluid supply line 3 lies below a fluid level 51 of the fluid in the evaporator sump 52. The fluid from the evaporator sump 52 can flow into the intermediate cooling fluid supply line 3, in particular using gravity. In particular, the intercooling fluid supply line 3 does not require any control for supplying fluid from the evaporator sump 52. However, it is conceivable to provide a control for supplying liquid fluid to the intercooling fluid supply line 3.

As shown in Fig. 12, the intercooler 40 preferably has an intercooling sump 44, with a return line 2 or a fluid line channel 15 for returning fluid from the intercooling sump 44 into the evaporator sump 52, preferably laterally, extending from a bottom of the intercooling sump extends the evaporator sump 52. In particular, the heated vaporous fluid that can be output from the first compressor stage 10 and the intermediate cooling fluid are each taken from the evaporator sump 52.

A further return line 1, which can also be referred to in particular as a fluid line channel 15, preferably extends for returning fluid from the Condenser sump 64 into the evaporator sump 52 from the condenser sump 64 directly, preferably laterally, into the evaporator sump 52. In particular, the return line 2 and the further return line 1 are fluidly separated from one another. “Fluidically separated from each other” means that the fluid from the return line 2 and the further return line 1 cannot mix in one line, but are only mixed with one another in the evaporator sump 52. With regard to the lines 1, 2 and 3, Figs. 12 and 14 an identical arrangement of the lines 1, 2, 3.

Fig. 14 shows a further preferred embodiment of the heat pump 100, as shown in Fig. 12. 14 shows a hydraulic diagram as in FIG.

According to the further preferred embodiment of the heat pump, as shown in Fig. 14, the intercooling fluid supply line 3 is connected to at least one further intercooler 4, 5. The further intercooler 5 can be arranged in the steam channel 30 between the evaporator 50 and the condenser 60. The further or even further intercooler 4, 5 can in particular be arranged after an output of the first compressor stage 10.

12 and 14, the intercooling sump 44 is designed to collect fluid that can flow through the intercooling fluid supply line 3, the fluid from the intercooling sump 44 to the evaporator sump 52 via the return line 2, or also fluid line channel 15 called, can be supplied. In particular, the return line 2 and the further return line 1 each have an opening 55 to the evaporator sump 52 at spaced positions of the evaporator sump 52. In particular, the opening 55 of the further return line 1 into the evaporator sump 52 is arranged below a fluid level 51 of the evaporator sump 52. Furthermore, in particular, the opening 55 of the return line into the evaporator sump 52 is arranged below a fluid level 51 of the evaporator sump 52.

The intermediate cooling fluid supply line 3 or an engine cooling line 33 from the evaporator sump 52 to an engine cooling system 34 of the first compressor stage is preferred 10 arranged to conduct fluid from the evaporator sump 52 to the engine cooling 34 for cooling a motor M assigned to the first compressor stage 10. In particular, the intermediate cooling fluid supply line 3 and/or the engine cooling line 33 extend from the evaporator sump 52 via the engine cooling 34 of the first compressor stage 10 to the effect element 42 in order to supply fluid from the evaporator sump 52 to the engine cooling 34 for cooling an engine assigned to the first compressor stage 10 M and to the effective element 42 (see Figs. 12 and 14).

As shown in Figs. 12 and 14, a further engine cooling line 35 is arranged from the evaporator sump 52 to a further engine cooling system 36 of the second compressor stage 20 in order to supply fluid from the evaporator sump 52 to the further engine cooling system 36 for cooling a motor M assigned to the second compressor stage 20 lead. The motors M, which are assigned to the compressor stages 20, 30, 80, can be cooled with fluid from the evaporator sump 52. The fluid from the evaporator sump 52 is cooler than the fluid from an intercooling sump 44. The fluid from one of the intercooling sumps 44 is in turn cooler than the fluid from the condenser sump 64.

Like, for example, Figs. 1, 2, 8 or 12 to 15, a ball bearing adapter line 74 is preferably arranged from the intermediate cooling sump 44 to a ball bearing adapter 76, which is assigned to the first compressor stage 10, in order to supply fluid from the intermediate cooling sump 44 for cooling the at least one ball bearing adapter 76 to direct. In particular, a compressor cooling channel 77 is arranged from an output of the ball bearing adapter 76 to the first compressor stage 10 in order to direct fluid from the ball bearing adapter 76 to the first compressor stage 10 in order to irrigate compressed fluid in the first compressor stage 10 with the fluid from the ball bearing adapter 76.

Furthermore, a ball bearing adapter line 74 is preferably arranged from the condenser sump 64 to a ball bearing adapter 76, which is assigned to the second compressor stage 20, in order to direct fluid from the condenser sump 64 for cooling the at least one ball bearing adapter 76. In particular, a compressor cooling channel 77 is arranged from an output of the ball bearing adapter 76 to the second compressor stage 20 in order to direct fluid from this ball bearing adapter 76 to the second compressor stage 20 in order to compress fluid in the second compressor stage 20 with the fluid from the ball bearing adapter 76, which is the second compressor stage 20 is assigned rain. In an embodiment not shown, the ball bearing adapter can also receive fluid for cooling from the intermediate cooling fluid supply line 3 and thus be connected in series or parallel to the same line to which the engine cooling 36 is also connected.

Preferably, at least one packing body 7 is arranged in an area around the first compressor stage 10 to dissipate heat, in particular to increase the surface area and thus for optimized cooling of the steam. The at least one packing body 7 is arranged in particular around the intake port 12 of the first compressor stage 10 (cf. with FIG. 14). In a particularly advantageous embodiment, the at least one packing comprises numerous individual packings which are distributed around the intake port 12 of the first compressor stage 10.

As can be seen from FIG. 14, for example, a further intercooler 4 is preferably arranged in the intercooling fluid supply line 3. In particular, due to the arrangement of the intercooler 40, the further intercooler 4 and the even further intercooler 5, the steam, i.e. the evaporated and compressed fluid, in the intercooling fluid supply line 3, after exiting the first compressor stage 10, first passes the further intercooler 4 and then the further one Intercooler 5 and/or the intercooler 40. It is conceivable that the heat pump 100 only includes the further intercooler 4 and the even further intercooler 5 (see FIG. 14). It is also conceivable that the heat pump 100 only includes the intercooler 40 (see FIG. 12). It is also conceivable that the heat pump 100 only includes the intercooler 40 and the further intercooler 4 or the even further intercooler 5. In an embodiment not shown, it is also possible for the intercooler 5 to extend over the entire length of the steam channel 30, thus resulting in particularly efficient cooling of the steam flowing past.

The further intermediate cooler 4 is preferably designed as a heat exchanger 82, which is designed as a pipe 56 and/or as a tube bundle 56a and has a pipe volume through which fluid from the evaporator sump 52 flows in order to enable indirect cooling 8 of the steam. Figs. 8 to 10 show, for example, the indirect cooling 8 through the heat exchanger 82. The heat exchanger 82 has already been discussed in detail, to which reference is made at this point. The second compressor stage 20 is preferably arranged between the evaporator 50 and the condenser 60 and the intercooler 40, the further intercooler 4 and/or the further intercooler 5 are arranged at a distance from a suction area of the second compressor stage 20. As can be seen, for example, in Fig. 14, the intercooler 40 and/or the further intercooler 4 and/or the further intercooler 5 can be in the upper evaporator part 54 and/or starting from the first compressor stage 10 in the steam channel 30 up to the sink 32 be arranged.

To regulate a fluid level, i.e. a fluid level 51, the condenser sump 64 and/or the evaporator sump 52 and/or the intermediate cooling sump 44 can each have a level control. Level control can preferably be dispensed with if the fluid level 51 in the individual sumps 52, 44, 64 controls itself via the height of the outflows, i.e. if self-regulation, as already described, is possible. Then the fluid level 51 does not need to be actively regulated. In the present case, drains mean, for example, the opening 65 of the vapor supply line 92 into the condenser 60, and/or the opening 65 of the return line 2 into the intercooling sump 44 and/or the opening 65 of the intercooling fluid supply line 3 into the evaporator sump 52, as shown, for example, in FIGS. 12, 13 and 14 is shown.

As already explained, FIG. 15 shows a compressor map 170 of an N-stage compressor, the compressor map 170 defining a relationship between a pressure ratio and a mass flow.

16 shows a three-dimensional envelope surface 180 over a corrected mass flow, the dotted lines representing measured speed characteristics 181. The speed characteristics 181 are dependent on the corrected mass flow WCcorr and the compression ratio PiC. Similar to FIG. 15, the surge limit 171 is shown in FIG. 16 as a function of the corrected mass flow and the compressor ratio. The envelope surface 180 is shown as a compensation surface (3D fit), which has been adapted to the measured speed characteristics 181. The envelope surface 180 initially increases with increasing corrected mass flow and increasing speed, which is represented by a three-dimensional monotonically increasing function. After reaching a mass flow of approximately 0.8, the envelope surface 180 branches off in a monotonically decreasing course. Fig. 17 shows a three-dimensional representation for determining a volume flow to determine the corrected mass flow. The volume flow is given by a function which depends on the excluded electrical power P _ei and the speed of the compressor stage 10, 20. Preferably, 100 compressor stages 10, 20 are used in the heat pump, which are identical in construction. It is conceivable to use compressor stages 10, 20 that differ from one another.

The volume flow cannot be measured directly. Instead, this is determined indirectly via a stored 3D map 190, which is specific for a compressor drive used. The volume flow is derived depending on the electrical power P _ei consumed and the speed of the compressor drive with the help of the 3D map in the 3D map 190 (see dotted curves 191), in which the measured values 191 are entered in the 3D map 190 become. After determining the volume flow, mass flow can be corrected, in particular by applying knowledge of the molar mass of the fluid at a given pressure and temperature.

According to a preferred embodiment, the heat pump 100 includes the evaporator 50 for vaporizing a fluid to obtain a vaporized fluid; the condenser 60 for condensing a compressed fluid; and the compressor with a first compressor stage 10 and a second compressor stage 20, wherein the compressor is arranged in the flow direction of the evaporated fluid in an operation of the heat pump 100 between the evaporator 50 and the condenser 60 and is designed to compress the evaporated fluid in order to to obtain the compressed fluid. In addition, the heat pump 100 includes a value detection device 95 for detecting a first value P1, which corresponds to a first pressure ratio between an input of the first compressor stage 10 and an output of the first compressor stage 10 or is dependent on the first pressure ratio; and a controller 96 for controlling a first speed of the first compressor stage 10 and a second speed of the second compressor stage 20, the controller 96 being designed to control the second speed of the second compressor stage 20 depending on the first value P1. The value capture device 95 and the controller 96 can communicate with each other and can each communicate with components of the heat pump 100, as indicated in FIG. 18 by the arrows in opposite directions. The output of the first compressor stage 10 includes an area immediately after the first compressor stage 10 as well as an area between first compressor stage 10 and the second compressor stage 20, in particular an area in the steam channel 30.

Preferably, the value detection device 95 is designed to detect a second value P2, which corresponds to a second pressure ratio between an output of the second compressor stage 20 and an input of the first compressor stage 10 or is dependent on the second pressure ratio, and wherein the controller 96 is designed to further control the second speed depending on the second value P2. In particular, an area of the input of the second compressor stage 20 can connect to the area of the output of the first compressor stage 10. For example, the area of the output of the first compressor stage 10 can end in the depression 32 and the area of the inlet of the second compressor stage 20 can begin in the depression 32 of the steam channel 30 (see FIG. 18).

18 shows the hydraulic diagram of the heat pump 100, in which the first temperature sensor 91, the second temperature sensor 92 and the third temperature sensor 93 are shown. 18 also shows the controller 96 and the value recording device 95, which communicate with the individual components of the heat pump 100 as well as with each other. The cooling liquid 97 indicates the cold water temperature that a user of the heat pump 100 is provided with as the actual temperature. The first temperature sensor 91 measures the first temperature TU in the evaporator sump 52 and thus before the first compressor stage 10. The second temperature sensor 92 measures the second temperature TI3 in the intermediate cooling sump 44 and thus after the first compressor stage 10 and before the second compressor stage 20. The third Temperature sensor 93 measures the third temperature TI2 in the condenser sump 64 and thus after the second compressor stage. As Fig. 18 suggests, the user is provided with a cooling power 103, which serves as a power for cooling customer water. This is a service that is provided to the user or customer. The dissipated heat output 105 is heat output that is dissipated via a dry cooler. The motors M of the compressor stages 10, 20 absorb the electrical power 104, which is the power absorbed by the heat pump 100, which is absorbed via the two compressor stages 10, 20. For example, a maximum pressure ratio of the first compressor stage can be 10 P1 =3.7. For example, a maximum pressure ratio of the second compressor stage can be 20 P2 = 3.7. In this case, for example, the maximum total pressure ratio P _tot of the heat pump 100 Ptot=P1 * P2 =3.7 *3.7 =13.7. In connection with Fig. 19 it can further be summarized that in case 1 the first compressor stage 10 is operated constantly at a pressure ratio of, for example, P1 = 2.7 and the second compressor stage 20 is operated in a pressure ratio P2 between zero and 2.7 . If the first compressor stage 10 and the second compressor stage 20 are each operated at a pressure ratio of P1 = P2 = 2.7, the heat pump 100 switches from case (first performance range 98) to case 2 (second performance range 99. In the second performance range 99 increase the compression ratios of the first compressor stage 10 and the second compressor stage 20 each vary equally from P1 =P2=2.7 to P1 =P2=3.7.

The controller 96 is preferably designed to use the first value P1 as the actual value and the second value P2 as the setpoint. Furthermore, the controller 96 is preferably designed to increase the speed of the second compressor stage 20 if the actual value is greater than the setpoint, or to reduce the speed of the second compressor stage 20 if the actual value is smaller than the setpoint. By comparing the actual value with the setpoint, the speeds of the first and second compressor stages 10, 20 can each be adjusted such that the second compressor stage can be used efficiently independently of the first compressor stage 10. An independent adjustment of the speeds of the first and second compressor stages 10, 20 is achieved in that each motor M of the compressor stages 10, 20 has its own motor shaft that is to be driven. The first value P1 indicates a compression ratio of the first compressor stage 10 according to P1 =TI3/TI1. The second value P2 indicates a compression ratio of the second compressor stage 20 according to P2=TI2/TI3.

Preferably, the value recording device 95 is further designed to determine an actual temperature of a coolant 97 dispensed on the evaporator side, and in which the controller 96 is designed to control the speed of the first compressor stage 10 depending on the actual temperature of the coolant 97 and a predefined one Set the target temperature of the coolant 97. During operation of the heat pump 100, it can increase the actual temperature of the coolant 97 dispensed on the evaporator side, since as a result of the operation of the heat pump 100, the fluid circulating in the heat pump, i.e. the coolant 97, assumes a higher temperature over time.

The control is preferably designed to be dependent on one

Power requirement in a first power range 98, the first compressor stage 10 to operate with a higher pressure ratio than the second compressor stage 20, with a difference in the pressure ratios of the first compressor stage 10 and the second compressor stage 20 decreasing as performance requirements increase (see case 1 in Fig. 19), and in order to achieve both in a second performance range 99 to operate the first compressor stage 10 as well as the second compressor stage 20 in such a way that pressure ratios of the two compressor stages 10, 20 in the second performance range 99 are approximately the same, or in particular the same within a range of plus/minus 20 percent, and/or the same as the power requirement increases increase (see case 2 in Fig. 19), wherein the second performance range 99 includes greater performance requirements than the first performance range 98, with a boundary 94 between the first performance range 98 and the second performance range 99 through the first compressor stage 10 and / or through the second Compressor stage 20 is set. Fig. 19 shows a diagram to illustrate a control of the compressor stages 10, 20 of the heat pump 100 depending on the speeds of the first and second compression stages 10, 20 in the first performance range 98 and in the second performance range 99. In case 2, i.e. the second performance range 99 , a higher power TT is implemented than in the first case, i.e. in the first power range 98 (see FIG. 19). 19 can also be seen that the first compressor stage 10 operates at a constant power value, in particular TT=2.7. The constant power value TT of the first compressor stage 10 corresponds to a setpoint in the first line area 98 at which the first compressor stage is to be operated. The second compressor stage 20 begins with an initially lower power TT, but increasingly approaches the setpoint of the first power stage 10. If the second compressor stage 20 also reaches the setpoint of the power TT, both compressor stages 10, 20 switch over in an operation which corresponds to case two, i.e. the second power range 99. In the second performance range, the pressure ratio of the first compressor stage 10 and the second compressor stage 20 preferably increases uniformly. At the border 94, operation in the first power range 98 is switched to operation in the second power range 99/9. In particular, with a total pressure ratio of ((772)/(771)), the heat pump 100 switches from operation in the first performance range 98 to operation in the second performance range 99, where p(TZl) indicates a saturated steam pressure in the evaporator sump 52, which in particular can be measured by the first temperature sensor 91, and where p(Tl2) indicates a saturated steam pressure in the condenser sump 64, which can be measured in particular by the third temperature sensor 93 (cf. with FIG. 18). The first compressor stage 10 and the second compressor stage 20 preferably have radial wheels of different sizes, the controller 96 being designed to control the first compressor stage 10 in the first performance range 98 to a constant first pressure ratio as a setpoint, and to control the second compressor stage 20 increasing power requirement to an increasing second pressure ratio as a setpoint, and in order to accommodate an increasing power requirement in the second performance range 99 both by the first compressor stage 10 and by the second compressor stage 20 (see mi Fig. 19). For example, the setpoint for the compressor stages 10, 20 used is 2.7, as already explained. If other compressor stages are used, the setpoint may be different. In particular, the setpoint is specific to the compressor. The radial wheel of the first compressor stage 10 is preferably designed to be larger than the radial wheel of the second compressor stage 20. Both radial wheels are designed in particular so that they both pass through approximately the same mass flow. Since the temperature in front of the second radial wheel, ie the radial wheel of the second compressor stage 20, is higher than in front of the first radial wheel, ie the radial wheel of the first compressor stage 10, the second radial wheel must be made smaller.

The controller 96 is preferably designed to use a maximum value from a function of the second value P2 or a predefined constant const as a setpoint for controlling the second speed of the second compressor stage 20. The predefined constant depends on the compressors used and is preferably in the range between 1 and 5, i.e. 1 <const. <5, more preferably in the range between 2 and 4, the constant const=2.7 is particularly advantageous. The constant is the optimal pressure ratio of the first compressor. The maximum value of the second speed of the second compressor stage 20 is therefore given by:

Maximum value = P2 or const.

The maximum value is given by a maximum function which takes the highest value from the second value P2 or a predefined constant const.

Preferably, the maximum function is a root function and the predefined constant is the limit 94 between the first and second power ranges 98, 99. In particular, the maximum function is given by ((n2)/(ni)) ^1/2 , where p(Tll) indicates a saturated steam pressure in the evaporator sump (52), which can be measured in particular by the first temperature sensor 91, and where p(TL2) indicates a saturated steam pressure in the condenser sump 64 indicates which can be measured in particular by the third temperature sensor 93 (see FIG. 18).

The first value P1 is given by the ratio: P1 =TI3/T11.

The second value P2 is given by the ratio: P2 =TI2/TI3.

A total compression ratio P _tot , as shown in FIG. 19, is given by the product of the first value P1 and the second value P2, namely by:

P _tot =P1*P2= (TI3/TI1) * (TI2/TI3) = TI2/ TI1

As can be seen, for example, from FIG. 19, the first value P1 and the second value P2 are geometrically added (hence 2*a/2=a) to obtain the total compression ratio Ptot.

The value detection device 95 preferably comprises a first temperature sensor for detecting a first temperature TU with respect to the evaporator 50, and a second temperature sensor for detecting a second temperature TI3 with respect to an output of the first compressor stage 10, wherein the value detection device 95 is designed to measure the first value P1 to determine the first temperature TU and the second temperature TI3. 18 shows, for example, where in the hydraulic diagram of the heat pump 100 the temperature sensors could be arranged, which indicates where which of the temperatures TU, TI2 and TI3 can be measured.

Preferably, the first temperature sensor is arranged in the evaporator sump 52 of the evaporator 50 in order to detect the first temperature TU before the first compressor stage 10, and the second temperature sensor is arranged in an intermediate cooling sump 44 in order to detect the second temperature TI3 after an output of the first compressor 10 capture. Preferably, the output of the first compressor 10 includes the sink 32 in the steam channel 30, which fluidly connects the first compressor stage 10 and the second compressor stage 20. The steam channel 30 is preferably provided between the first compressor stage 10 and the second compressor stage 20 in order to guide compressed fluid from the first compressor stage 10 into the second compressor stage 20, the intermediate cooling sump 44 or the container 45 being arranged in the steam channel 30. The first compressor stage 10 and the second compressor stage 20 are fluidly connected to one another through the steam channel 30.

18, the value acquisition device 95 comprises a third temperature sensor in order to measure a third temperature TI2, the value acquisition device 95 being designed to obtain the second value P2 from the third temperature TI2 and the first temperature (TU). to determine. The third temperature sensor is preferably arranged in the condenser sump 64 in order to detect the third temperature TI2 after the second compressor stage 20. 18 shows a hydraulic diagram highlighting temperature sensors for guiding the second compressor, particularly where the temperature sensors could be located in the heat pump 100 to measure the respective temperature TU, TI2 or TI3. 8, for example, the second temperature sensor can also be arranged in the container 45 instead of in the intermediate cooling sump 44, i.e. in a sump 44, 45, which fluidly connects the first compressor stage 10 and the second compressor stage to one another.

Preferably extends from the condenser sump 64 into the intercooling sump

44 (Fig. 18) or in the container 45 (Fig. 8) a fluid line channel 15 extends to fluid from the condenser sump 64 into the intermediate cooling sump 44 or into the container

45, and wherein a further fluid line channel 15 extends from the intercooling sump 44 or the container 45 in the evaporator sump 52 in order to direct fluid from the intercooling sump 44 or the container 45 into the evaporator sump 52. By connecting the sumps 64, 44, 45 and 52 to one another via the fluid lines 15, the fluid in each of the sumps 64, 44, 45 and 52 is increased during operation of the heat pump 100. This can result in the need to regulate the compressor stages of the heat pump, as shown in FIG. 19, simply because of the running time of the heat pump 100.

A bridging channel 62 is preferably arranged between the first compressor stage 10 and the condenser 60 in order to bridge the second compressor stage 20, wherein in the bridging channel 62 a cross-sectional reducing element 70 is arranged to adjust a cross-section of the bridging channel 62 in order to regulate a flow of compressed fluid from the first compressor stage 10 to the condenser 60, wherein the cross-sectional reducing element 70 has a closed one during operation of the second compressor stage 20 takes position. The bridging channel 62 and the cross-sectional reducing element 70 have already been described in detail, to which reference is made.

The speeds of the compressor stages 10, 20 can be increased for two reasons, since both the user side and the dry cooler side act on the heat pump. For example, the cold water temperature 97 can rise. The water used by the user, which is provided to him, simply has a higher temperature, i.e. the user needs more cooling capacity. In this case, the speed of the first compressor stage 10 is increased, as a result of which more electrical power 104 is supplied to the heat pump 100. This increases the cooling capacity 103 generated by the heat pump. In another case, cold water temperature 97 can increase if the water temperature from the recooler to the condenser increases, for example if the outside temperature rises and the recooler can only dissipate the heat energy with greater energy expenditure. In this case, for example, the measured temperatures TU, TI3 and TI2 increase, which ultimately increases the cold water temperature that the user receives. For the operation of the compressor stages 10, 20, this means that first the speed of the first compressor stage is increased and, secondly, the speed of the second compressor stage is also increased. If the cooling water temperature increases, the electrical power consumed 104 by the heat pump 100 also increases.

The heat pump described herein allows the second compressor to be used more efficiently, whereby the heat pump as such can be used more efficiently. In addition, it is prevented that the second compressor stage is operated in the surge limit or in the swallow limit.

In particular, the first compressor stage provides the user with a requested cooling capacity. The second compressor stage 20 removes the heat from the heat pump 100 to the dry cooler. If the first compressor stage 10 provides the user with more cooling capacity, the compressor stage 20 will do this More heat output is delivered to the dry cooler, which increases the electrical power consumed by the heat pump.

Another aspect relates to a method for operating a heat pump 100 with an evaporator 50 for evaporating a fluid to obtain a vaporized fluid, the evaporator 50 having an evaporator sump 52; a condenser 60 for condensing vaporized fluid compressed by an N-stage compressor, the condenser 60 having a condenser sump 64, a condensation region 66 and a holding region 67 for holding a vaporous fluid remaining after the condensation region 66; the N-stage compressor, which includes N compressors, where N is a natural number greater than or equal to one, the N-stage compressor being arranged between the evaporator 50 and the condenser 60; a steam channel 30, which couples at least two of the N compressors of the N-stage compressor between the evaporator 50 and the condenser 60, and a steam guide line 92, which is arranged between the condenser 60 and the evaporator 50, to transport vaporous fluid from the holding region 67 of the Condenser 60 into evaporator 50 with the following steps:

evaporating fluid through evaporator 50;

feeding the vaporized fluid into the first compressor stage 10 to compress the vaporized fluid,

directing the compressed fluid through the vapor passage 30 to pass the N compressors; to finally reach the condenser 60;

condensing the compressed fluid in the condensation region 66 and maintaining uncondensed fluid in the holding region 67; and

Returning the evaporated fluid via the vapor guide line 92 from the holding area 67 to the evaporator 50.

Another aspect relates to a method of manufacturing a heat pump 100 having an evaporator 50 for evaporating a fluid to obtain a vaporized fluid, the evaporator 50 having an evaporator sump 52; a condenser 60 for condensing vaporized fluid compressed by an N-stage compressor, the condenser 60 having a condenser sump 64, a condensation region 66 and a holding region 67 for holding a vaporous fluid remaining after the condensation region 66; the N-stage compressor, which comprises N compressors, where N is a natural number larger or is equal to one, where the N-stage compressor is arranged between the evaporator 50 and the condenser 60; a steam channel 30, which couples at least two of the N compressors of the N-stage compressor between the evaporator 50 and the condenser 60, and a steam guide line 92, which is arranged between the condenser 60 and the evaporator 50, to transport vaporous fluid from the holding region 67 of the Condenser 60 into evaporator 50 with the following steps:

arranging the evaporator 50, the N-stage compressor and the condenser 60; connecting the evaporator, the N-stage compressor and the condenser 60 via the vapor passage 30; and

Connecting the evaporator and condenser 60 via the vapor guide line 92 to create a circuit in which the fluid circulates.

Another aspect relates to a method for operating a heat pump 100 with an evaporator 50 for evaporating a fluid to obtain a vaporized fluid, the evaporator 50 having an evaporator sump 52; a condenser 60 for condensing a compressed fluid, the condenser 60 having a condenser sump 64; a compressor with a first compressor stage

10 and a second compressor stage 20, wherein the compressor is arranged in the flow direction of the evaporated fluid in an operation of the heat pump 100 between the evaporator 50 and the condenser 60 and is designed to compress the evaporated fluid to obtain the compressed fluid; wherein the method includes the steps:

collecting an intercooling fluid in a container 45; and

Flowing through a heat exchanger 82 with a pipe 56 with the intermediate cooling fluid from the container 45, the pipe 56 in a flow area

11 is arranged between the first compressor stage 10 and the second compressor stage 20 in order to cool vaporous fluid in the flow region 11.

Another aspect relates to a method of manufacturing a heat pump 100 having an evaporator 50 for evaporating a fluid to obtain a vaporized fluid, the evaporator 50 having an evaporator sump 52; a condenser 60 for condensing a compressed fluid, the condenser 60 having a condenser sump 64; a compressor with a first compressor stage 10 and a second compressor stage 20, the method comprising: arranging the compressor in the flow direction of the evaporated fluid so that during operation of the heat pump 100, the compressor is arranged between the evaporator 50 and the condenser 60 to compress the evaporated fluid to obtain the compressed fluid;

arranging a container 45 for collecting an intercooling fluid; and arranging a heat exchanger 82 with a pipe 56 in a flow region 11 between the first compressor stage 10 and the second compressor stage 20 in order to allow the intermediate cooling fluid from the container 45 to flow through the pipe 56 when the heat pump is in operation and for vaporous fluid to flow through the pipe 56 in the flow region 11 to cool

Another aspect relates to a method for operating a heat pump 100 with an evaporator 50 for evaporating a fluid to obtain a vaporized fluid, the evaporator 50 having an evaporator sump 52; a compressor with a first compressor stage 10 and a second compressor stage 20, wherein the compressor is arranged in the flow direction of the evaporated fluid in an operation of the heat pump 100 between the evaporator 50 and a condenser 60 and is designed to compress the evaporated fluid in order to compress compressed fluid to obtain fluid; and the condenser 60 for condensing the compressed fluid; and an intercooler 40, which is connected to an intercooling fluid supply line 3 and which has an operating element 42, the operating element 42 being arranged between the first compressor stage 10 and the second compressor stage 20, the method comprising:

Supplying intercooling fluid via the intercooling fluid supply line 3 from the evaporator sump 52 into the operating element 42;

discharging a heated vaporous fluid through the first compressor stage 10; Interacting the intercooling fluid supplyable through the intercooling fluid supply line 3 with the heated vapor fluid output from the first compressor stage 10 to cool the vapor fluid.

Another aspect relates to a method of manufacturing a heat pump 100 having an evaporator 50 for evaporating a fluid to obtain a vaporized fluid, the evaporator 50 having an evaporator sump 52; a compressor with a first compressor stage 10 and a second compressor stage 20, the compressor being in the flow direction of the evaporated fluid in operation of the heat pump 100 is disposed between the evaporator 50 and a condenser 60 and is configured to compress the evaporated fluid to obtain compressed fluid; and the condenser 60 for condensing the compressed fluid; the method comprising:

Arranging an intercooler 40 with an effective element 42 between the first compressor stage 10 and the second compressor stage 20

Connecting the intercooler 40 to an intercooling fluid supply line 3, which extends from the evaporator sump 52 to the effect element 42, in order to ensure an interaction between an intercooling fluid, which can be supplied through the intercooling fluid supply line 3, and one that can be output from the first compressor stage 10 during operation of the heat pump 100 to cause heated vaporous fluid.

Another aspect relates to a method for operating a heat pump 100 with an evaporator 50 for evaporating a fluid to obtain evaporated fluid; a condenser 60 for condensing a compressed fluid; a compressor with a first compressor stage 10 and a second compressor stage 20, wherein the compressor is arranged in the flow direction of the evaporated fluid in an operation of the heat pump 100 between the evaporator 50 and the condenser 60 and is designed to compress the evaporated fluid in order to compress compressed fluid to obtain fluid; and a bypass channel 62 between the first compressor stage 10 and the condenser 60, the method comprising:

Bridging the second compressor stage 20 by adjusting a cross section of a cross section reducing element 70 in the bridging channel 62 to regulate a flow of compressed fluid from the first compressor stage 10 to the condenser 60.

Another aspect relates to a method of manufacturing a heat pump 100 with an evaporator 50 for evaporating a fluid to obtain evaporated fluid; a condenser 60 for condensing a compressed fluid; a compressor with a first compressor stage 10 and a second compressor stage 20, the compressor being arranged between the evaporator 50 and the condenser 60 in the flow direction of the evaporated fluid during operation of the heat pump 100 and is designed to compress the vaporized fluid to obtain compressed fluid; wherein the method includes

Arranging a bridging channel 62 between the first compressor stage 10 and the condenser 60 in order to bridge the second compressor stage 20,

Arranging a cross-sectional reduction element 70 in the bypass channel 62 to adjust a cross-section of the bypass channel 62 to regulate a flow of compressed fluid from the first compressor stage 10 to the condenser 60.

Another aspect relates to a method for operating a heat pump 100 with an evaporator 50 for evaporating a fluid to obtain a vaporized fluid; a condenser 60 for condensing a compressed fluid; and a compressor with a first compressor stage 10 and a second compressor stage 20, wherein the compressor is arranged in the flow direction of the evaporated fluid in an operation of the heat pump 100 between the evaporator 50 and the condenser 60 and is designed to compress the evaporated fluid in order to to obtain the compressed fluid, with the following steps:

Detecting a first value P1 that corresponds to a first pressure ratio between an input of the first compressor stage and an output of the first compressor stage or is dependent on the first pressure ratio; and controlling a first speed of the first compressor stage 10 and a second speed of the second compressor stage 20, the second speed of the second compressor stage 20 being controlled depending on the first value P1.

Another aspect relates to a method of manufacturing a heat pump 100 comprising: an evaporator 50 for vaporizing a fluid to obtain a vaporized fluid; a condenser 60 for condensing a compressed fluid; and a compressor with a first compressor stage 10 and a second compressor stage 20, with the following steps:

in an operation of the heat pump 100, arranging the compressor in the flow direction of the evaporated fluid between the evaporator 50 and the condenser 60 to compress the evaporated fluid to obtain the compressed fluid; and connecting a value detection device for detecting a first value that corresponds to a first pressure ratio between an input of the first compressor stage and an output of the first compressor stage or is dependent on the first pressure ratio with the compressor, the evaporator or the condensing; and connecting a controller for controlling a first speed of the first compressor stage 10 and a second speed of the second compressor stage 20 with the compressor, the second speed of the second compressor stage 20 being controlled as a function of the first value.

As already mentioned in the general part, individual aspects that are described in relation to the heat pump can also be implemented as a process step.

Preferably, a method for producing a heat pump 100, as described above, can be provided by producing the individual features and combining the individual features to form one of the heat pump 100 described above. The individual features will not be discussed again here in connection with the manufacturing process of the heat pump. Rather, reference is made at this point to the above description of the individual features, which can also be understood as a production process step.

Further preferably, a method for operating a heat pump 100 first comprises providing a heat pump 100, as described above.

To operate the heat pump, at least one, in particular the first, compressor stage 10 is operated. During operation of the first compressor stage 10, fluid is evaporated via the evaporator 50 and thus supplied to the first compressor stage. At the same time, liquid fluid is supplied to an effective element 42 and/or a heat exchanger 82 via the intermediate cooling fluid supply line 3. Evaporated and compressed fluid leaving the first compressor stage 10 is cooled as already described above. Furthermore, the method for operating a heat pump 100 includes adjusting the cross-sectional reduction element 70 into an open, closed position or into an intermediate position, as already described above. Depending on the position of the cross-sectional reduction element 70, the evaporated and compressed fluid leaving the first compressor stage 10 is either passed through the bridging channel 62 directly to the condenser 60 (inactive steam path) and/or via the steam channel 30 to the second compressor stage 20 (active steam path ). In an intermediate position of the cross-sectional reducing element 70, in particular the inactive and the active vapor path can be used to conduct the evaporated and compressed fluid. A description of the circulation of the fluid can be found in the above description, which is not repeated again in connection with the method for operating the heat pump in order to avoid redundancies avoid. Rather, reference is made here to the above description, which can also be understood as procedural steps for operating the heat pump.

In particular, the various features described can be combined with one another or exchanged for one another as desired. In particular, fluid and cooling water are used interchangeably. In particular, when the word steam is used, it means vaporized fluid.

Reference symbol list

1 additional return line

3 Intercooling fluid supply line

2 return line

4 additional intercoolers

5 another intercooler

7 fillers

8 indirect intercooling

10 first compressor stage

11 flow area

12 intake ports

14 control room

15 fluid line channel

16 maximum diameter

17 minimum diameter

20 second compressor stage

22 circulation pump

30 Steam Channel (Banana)

32 sink

33 engine cooling line

34 engine cooling

35 more engine cooling lines

36 more engine cooling

40 intercoolers

42 effect element

44 Intercooling sump

45 containers

46 first intercooler line

48 second intercooler line

49 ball bearing adapters 50 evaporators

51 fluid level

52 evaporator sump

54 upper evaporator part

55 opening in the evaporator

56 pipeline

56a tube bundle

56b spiral tube arrangement

57 sprinkler area

58 sprinkler device

59 first evaporator line

60 condensers

62 bridging channel

64 condenser sump

65 Opening of a pipe into a swamp

66 condensation area

67 holding area

68 level

70 cross-section reduction element

72 diameter of the cross-sectional reducing element

74 ball bearing adapter line

76 ball bearing adapters

77 compressor cooling channel

80 Nth compressor stage

82 heat exchangers

83 turns

90 Steam transfer flap/bridging flap

92 steam pipe

91 first temperature sensor

92 second temperature sensor 93 third temperature sensor

94 border

95 value recording device

96 control

97 Actual temperature of a coolant dispensed on the evaporator side

98 first management area

99 second performance range

TH first temperature

TI3 second temperature

TI2 third temperature

100 heat pump

101 helix

102 screw axle

103 cooling capacity

104 electrical power

105 power dissipated

170 compressor map/boundary lines

171 surge limit

172 dotted lines

180 envelope area

181 speed characteristic

P1 first value/actual value

P2 second value/setpoint

M engine

300 test stand 301 Compressor to be checked

302 pressure sensor

303 temperature sensor

304 steam flow

306 pipe

307 throttle valve

308 Rewind

309 sensor

310 pump

311 connection

2' evaporator

3' first compressor

4' intercooling

4a' intercooling sump

4c' pump

5' second compressor

6' capacitor

41′ container

71′ feed line

72' supply line

V0 steam bypass

50' evaporator

60' condenser

Claims

Patent claims

1 . Heat pump (100) comprising: an evaporator (50) for evaporating a fluid to obtain evaporated fluid; a condenser (60) for condensing a compressed fluid; a compressor with a first compressor stage (10) and a second compressor stage (20), wherein the compressor is arranged and designed in the flow direction of the evaporated fluid during operation of the heat pump (100) between the evaporator (50) and the condenser (60). to compress the vaporized fluid to obtain compressed fluid; and a bridging channel (62) between the first compressor stage (10) and the condenser (60) to bridge the second compressor stage (20), wherein a cross-section reducing element (70) is arranged in the bridging channel (62) to a cross section of the bridging channel (62) to regulate a flow of compressed fluid from the first compressor stage (10) to the condenser (60).

2. Heat pump (100) according to claim 1, wherein the first compressor stage (10) and the second compressor stage (209) are connected via a steam channel (30).

3. Heat pump (100) according to one of the preceding claims, in which the bridging channel (62) has an opening in the first compressor stage (10), the first compressor stage (10) having a suction port (12) for sucking in the evaporated fluid and a guide space (14) to direct the vaporous compressed fluid into the bridging channel (62).

4. Heat pump (100) according to one of the preceding claims, in which the condenser (60) has a tube bundle (56a) or a spiral tube arrangement (56b) through which liquid to be heated can flow, the tube bundle (56a ) or the spiral-shaped tube arrangement (56b) is arranged laterally with respect to a further opening of the bridging channel (62), and an intake port (12) of a compressor of the second compressor stage (20) is arranged above the tube bundle (56a) or the spiral-shaped tube arrangement (56b). is.

5. Heat pump (100) according to 4, wherein the further opening of the bridging channel (62) is arranged so that vaporous fluid that passes through the further opening into the Condenser (60) reaches the side of the tube bundle (56a) or the spiral tube arrangement (56b).

6. Heat pump (100) according to one of the preceding claims, wherein the cross-sectional reduction element (70) is designed to assume a closed position or an open position depending on the operation of the second compressor stage (20), wherein the cross-sectional reduction element (70) is designed to to assume the closed position when the second compressor stage (20) is switched on, or to assume the open position when the second compressor stage (20) is switched off.

7. Heat pump (100) according to claim 6, wherein the cross-sectional reduction element (70) is biased in the closed position by means of a spring element.

8. Heat pump (100) according to one of the preceding claims, wherein the cross-sectional reduction element (70) is a flap or a panel or a wing door or a non-return flap.

9. Heat pump (100) according to one of claims 6 to 8, wherein the heat pump (100) has a controller for controlling the cross-sectional reduction element (70) into the open position or the closed position.

10. Heat pump (100) according to one of claims 6 to 9, wherein the first compressor stage (10) is designed to build up a maximum affordable pressure, and the cross-sectional reduction element (70) is designed to assume the open position when a pressure ratio between one Condenser pressure (Th) and an evaporator pressure (Th) is smaller than the maximum affordable pressure of the first compressor stage (10) in order to lead compressed fluid from the first compressor stage (10) via the bridging channel (62) to the condenser (60).

11. Heat pump (100) according to one of claims 6 to 10, wherein the cross-sectional reduction element (70) is designed to assume the closed position when the pressure ratio between the condenser pressure (Th) and the evaporator pressure (Th) is greater than the maximum affordable pressure of the first Compressor stage is to lead compressed fluid from the first compressor stage (10) via the steam channel (30) to the second compressor stage (20).

12. Heat pump (100) according to one of the preceding claims, wherein the first compressor stage (10) can be operated with N further compressor stages, where N is a natural number greater than or equal to two.

13. Heat pump (100) according to claim 12, wherein the first compressor stage (10) and the N further compressor stages are arranged in a series connection, with N compressor stages two adjacent compressor stages each being connected via a steam channel (30).

14. A method of operating a heat pump (100) having an evaporator (50) for vaporizing a fluid to obtain vaporized fluid; a condenser (60) for condensing a compressed fluid; a compressor with a first compressor stage (10) and a second compressor stage (20), wherein the compressor is arranged and designed in the flow direction of the evaporated fluid during operation of the heat pump (100) between the evaporator (50) and the condenser (60). to compress the vaporized fluid to obtain compressed fluid; and a bypass channel (62) between the first compressor stage (10) and the condenser (60), the method comprising:

Bridging the second compressor stage (20) by adjusting a cross section of a cross section reducing element (70) in the bridging channel (62) to regulate a flow of compressed fluid from the first compressor stage (10) to the condenser (60).

15. A method of manufacturing a heat pump (100) having an evaporator (50) for vaporizing a fluid to obtain vaporized fluid; a condenser (60) for condensing a compressed fluid; a compressor with a first compressor stage (10) and a second compressor stage (20), wherein the compressor is arranged and designed in the flow direction of the evaporated fluid during operation of the heat pump (100) between the evaporator (50) and the condenser (60). to compress the vaporized fluid to obtain compressed fluid; wherein the method includes: arranging a bypass channel (62) between the first compressor stage (10) and the condenser (60) to bypass the second compressor stage (20);

Arranging a cross-sectional reduction element (70) in the bypass channel (62) to adjust a cross-section of the bypass channel (62) to regulate a flow of compressed fluid from the first compressor stage (10) to the condenser (60).