JP5630177B2 - Centrifugal compressor and heat pump - Google Patents

Description

  The present invention relates to a centrifugal compressor and a heat pump for compressing a gas phase process fluid.

  The centrifugal compressor (turbo compressor) discharges gas to the outer peripheral portion of the impeller and applies pressure to the gas by rotating the impeller at high speed. When a centrifugal compressor is used in a heat pump or a chemical plant, the centrifugal compressor compresses a gas phase process fluid (such as a heat medium).

  In the centrifugal compressor, since it is necessary to rotate the impeller at a high speed (for example, 30000 rpm), a contact type cannot be used as the shaft seal structure, and a non-contact type is generally used. A dry gas seal is generally known as a non-contact type seal used for a shaft seal structure of a centrifugal compressor.

  The prior art document information related to the invention of this application includes the following.

JP 2003-194423 A Japanese Patent Laid-Open No. 2003-166761 Japanese Patent No. 3298691 JP-A-8-178477

  By the way, in a centrifugal compressor using a non-contact type seal, since it is non-contact type, there is a possibility that a part of the gas phase process fluid may enter the bearing housing (gear box).

  For example, when a centrifugal compressor is used as a compressor of a heat pump, the centrifugal compressor compresses a gas phase heat medium, but during operation of the centrifugal compressor, the impeller side (heat pump loop side) Since the pressure is higher than the pressure in the bearing housing, the gas phase heat medium may circulate to the back surface of the impeller and flow into the bearing housing through a slight gap of the non-contact type seal.

  Some heat media used in heat pumps are very compatible with the lubricating oil. When such a heat medium flows into the bearing housing, the heat medium is excessively dissolved in the lubricating oil. (The viscosity of the lubricating oil changes, and the formation of an appropriate oil film thickness that exerts a lubricating action on the gear surface provided in the bearing housing is hindered), which may cause a problem.

  Furthermore, some heat media used in heat pumps are highly erosive to elastomer materials. If such a heat medium flows into the bearing housing, the sealing material such as packing used in the bearing housing deteriorates. There is a risk of malfunction.

  In order to suppress such problems, it is desirable that a centrifugal compressor using a non-contact type seal is configured so that a gas phase process fluid to be compressed does not enter the bearing housing as much as possible.

  Patent Document 1 describes that a lubricating oil in which a heat medium (refrigerant) is dissolved is heated to vaporize and recover the heat medium from the lubricating oil. However, in Patent Document 1, although the heat medium dissolved in the lubricating oil can be recovered, the penetration of the heat medium into the bearing housing cannot be suppressed.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a centrifugal compressor and a heat pump capable of suppressing the intrusion of a gas phase process fluid to be compressed into a bearing housing. .

  The present invention has been devised to achieve the above object, and is a centrifugal compressor having a non-contact type seal in a bearing housing that houses an impeller rotary shaft, and compressing a gas phase process fluid. The process fluid in the gas phase leaked into the bearing housing through the non-contact type seal from the impeller side is cooled and liquefied on the opposite side of the impeller of the non-contact type seal. The centrifugal compressor is provided with a cooling recovery mechanism for recovering the process fluid.

  The cooling recovery mechanism is provided on a side opposite to the impeller of the non-contact type seal, and provided on the cooling recovery mechanism housing so as to surround the periphery of the impeller rotating shaft. The cooling fins are formed in the cooling recovery mechanism housing, and the cooling fluid flow paths for passing the cooling fluid for cooling the cooling fins are formed in the vertical direction below the cooling recovery mechanism housing, and are cooled by the cooling fins. And a recovery hole for recovering the liquefied process fluid.

  A lubricating oil circulation line is provided for collecting the lubricating oil in the bearing housing and supplying the lubricating oil to the bearing housing again. The lubricating oil circulation line is heated and dissolved in the lubricating oil. A separation / recovery mechanism may be provided that vaporizes and separates the process fluid and collects the vaporized process fluid.

  The present invention also provides an evaporator for exchanging heat with a high-temperature heat source to evaporate the heat medium, a compressor for compressing the heat medium evaporated by the evaporator, and the compressor compressed by the compressor. A heat pump comprising: a condenser that exchanges heat with a low-temperature heat source to condense the heat medium; and an expansion valve that expands the heat medium condensed by the condenser and supplies the heat medium to the evaporator. As described above, the separation and recovery mechanism is configured to heat the lubricating oil by exchanging heat between the heat medium compressed by the centrifugal compressor and the lubricating oil. It is a heat pump.

  ADVANTAGE OF THE INVENTION According to this invention, the centrifugal compressor and heat pump which can suppress the penetration | invasion in the bearing housing of the gaseous-phase process fluid used as compression object can be provided.

It is a schematic block diagram of the heat pump using the centrifugal compressor which concerns on one embodiment of this invention. It is sectional drawing which shows the cooling recovery mechanism of the centrifugal compressor of FIG. It is sectional drawing which shows the cooling recovery mechanism of the centrifugal compressor which concerns on other embodiment of this invention. FIG. 4 is a sectional view taken along line AA in FIG. 3.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic configuration diagram of a heat pump using the centrifugal compressor according to the present embodiment.

  As shown in FIG. 1, a heat pump 100 includes an evaporator (not shown) that heat-exchanges the heat medium with a high-temperature heat source and evaporates the heat medium, and a centrifugal compressor that compresses the heat medium evaporated by the evaporator. The compressor 1, the condenser 101 that exchanges heat between the heat medium compressed by the centrifugal compressor 1 and the low-temperature heat source to condense the heat medium, and the heat medium condensed by the condenser 101 is expanded and supplied to the evaporator. And an expansion valve (not shown). The evaporator, the centrifugal compressor 1, the condenser 101, and the expansion valve are sequentially connected by a heat medium circulation line 102, and the heat medium evaporated by the evaporator into a gas phase is supplied to the centrifugal compressor 1. It has become so.

  The temperature of the high-temperature heat source supplied to the evaporator is higher than the environmental temperature, for example, 100 to 150 ° C. The temperature of the heat medium during normal operation is, for example, 100 to 150 ° C. for the evaporator and 150 to 180 ° C. for the condenser 101. The heat pump 100 is, for example, an industrial high-temperature heat pump used for steam reheating and the like.

  The heat medium circulation line 102 between the condenser 101 and the expansion valve is provided with a liquid receiver 103 that stores the heat medium. An oil separator 104 for separating and recovering the lubricating oil leaked from the centrifugal compressor 1 is provided in the heat medium circulation line 102 between the centrifugal compressor 1 and the condenser 101. The oil separator 104 is connected to a later-described lubricating oil container 42 through an oil recovery line 105, and is configured to recover the lubricating oil separated by the oil separator 104 into the lubricating oil container 42. The oil separator 104 has been used conventionally, and the detailed structure is omitted, but the liquid level detected by the level sensor 104a (the liquid level of the separated lubricating oil) is equal to or higher than the upper limit threshold. The two-way valve 105a provided in the oil recovery line 105 is opened to collect the lubricating oil in the lubricating oil container 42, and the liquid level (lubricating oil level) detected by the level sensor 104a is the lower limit threshold value. When the following occurs, the two-way valve 105a is closed to prevent the heat medium from entering the lubricating oil container 42 side.

  Next, the centrifugal compressor 1 according to the present embodiment will be described.

  The centrifugal compressor 1 has an impeller housing part 10 and a gear box part 20.

  The impeller housing portion 10 includes an impeller 11 provided with a plurality of blades (not shown), and an impeller housing 16 that houses the impeller 11. The impeller housing 16 includes a suction port portion 12 for taking in a vapor phase heat medium from the evaporator, an impeller housing portion 13 for housing the impeller 11, an annular diffuser flow path 14 connected to the impeller housing portion 13, A scroll channel 15 connected to the outer peripheral edge of the diffuser channel 14 is formed.

  The impeller 11 is attached to the end of the impeller rotating shaft 21. The impeller 11 is rotated integrally with the impeller rotating shaft 21 by a driving force of a motor 24 described later, thereby discharging a gas phase process fluid (here, a heat medium) radially outward.

  The suction port portion 12 is provided on the upstream side of the impeller housing 16 so as to be coaxial with the impeller 11. Further, the suction port 12 is formed so that the opening area gradually decreases from the upstream side toward the downstream side.

  The impeller accommodating portion 13 is formed so that the opening area gradually increases from the upstream side toward the downstream side so as to accommodate the impeller 11. Further, the upstream side of the impeller accommodating portion 13 communicates with the suction port portion 12.

  The annular diffuser channel 14 is formed on the downstream side portion of the impeller housing 16 so as to surround the impeller accommodating portion 13. Further, a scroll flow path 15 that discharges a compressed gas-phase process fluid (here, a heat medium) to the condenser 101 is connected to the outer peripheral edge of the diffuser flow path 14.

  That is, the impeller housing portion 10 discharges the gas phase process fluid (here, the heat medium) taken in via the suction port portion 12 from the diffuser passage 14 to the scroll passage 15 by the rotation of the impeller 11. It is configured so as to compress (temperature increase / pressure increase).

  The gear box portion 20 includes an impeller rotating shaft 21, a bearing housing (gear box) 29 that accommodates the impeller rotating shaft 21, a pair of bearings 22 and 23 provided inside the bearing housing 29, and the bearing housing 29 side. A motor 24 that is attached to the motor, a driven gear 26 that is fitted to the impeller rotary shaft 21, a drive gear 27 that is fitted to the motor drive shaft 25, and a motor made of an elastomer material that seals the motor drive shaft 25. A shaft seal 28 and a dry gas seal 30 as a non-contact type seal are provided.

  The impeller rotating shaft 21 is rotatably supported in a bearing housing 29 by a pair of bearings 22 and 23. A driven shaft gear 26 that meshes with the drive gear 27 is fitted on the impeller rotary shaft 21 positioned between the pair of bearings 22 and 23. An annular protrusion 21 a to which a rotating ring 31 constituting a dry gas seal 30 described later is attached is formed on the peripheral surface of the impeller rotating shaft 21 between the bearing 22 and the impeller 11.

  As shown in FIG. 1, the motor drive shaft 25 of the motor 24 is inserted from the side of the bearing housing 29 and is rotatably supported by a bearing (not shown). The motor drive shaft 25 is fitted with a drive gear 27 having a larger diameter than the driven shaft gear 26. A motor shaft seal 28 that seals the motor drive shaft 25 is provided on the side of the bearing housing 29 through which the motor drive shaft 25 is inserted. In addition, in the bearing housing 29, lubricating oil is injected in order to suppress wear of the driven shaft gear 26 and the drive gear 27 that mesh with each other.

  The dry gas seal 30 includes a rotary ring 31 provided on the impeller rotary shaft 21 side and a fixed ring 32 provided on the bearing housing 29 side. The rotary ring 31 is fixed to the impeller rotary shaft 21 via the protrusion 21a. On the other hand, the fixed ring 32 is attached to a protrusion 20a formed inside the bearing housing 29 so as to be movable in the axial direction via a spring (not shown). A plurality of spiral grooves (not shown) are formed on the side surface of the rotating ring 31 facing the fixed ring 32.

  In other words, when the rotating ring 31 rotates integrally with the impeller rotating shaft 21, the dry gas seal 30 causes dynamic pressure to act between the rotating ring 31 and the fixed ring 32 by the plurality of spiral grooves, thereby rotating the impeller rotating shaft 21. It is configured to seal. This dynamic pressure separates the stationary ring 32 from the rotating ring 31 against the biasing force of the spring. On the other hand, when the impeller rotating shaft 21 is stopped, the rotating ring 31 and the stationary ring 32 are in contact with each other by the biasing force of the spring.

  The bearing housing 29 is connected to a lubricating oil circulation line 40 that collects the lubricating oil in the bearing housing 29 and supplies the lubricating oil into the bearing housing 29 again. One end of the lubricating oil circulation line 40 is connected to the lower part of the bearing housing 29 in the vertical direction in order to collect the lubricating oil accumulated in the bearing housing 29. The other end of the lubricating oil circulation line 40 is connected to the driven shaft gear 26. And the drive gear 27 are connected to an appropriate position of the bearing housing 29 so as to supply lubricating oil.

  In the lubricating oil circulation line 40, a two-way valve 41, a separation and recovery mechanism 45 described later, a lubricating oil container 42, a lubricating oil pump 43, and an oil cooler 44 are sequentially provided from one end side to the other end side. The lubricating oil container 42 is for storing lubricating oil, and the oil cooler 44 is for cooling the lubricating oil. A cooling water supply line 44a is connected to the oil cooler 44, and heat is exchanged between the cooling water supplied from outside the system and the lubricating oil to cool the lubricating oil. During operation of the centrifugal compressor 1, the two-way valve 41 is opened and the lubricating oil pump 43 is driven, so that lubricating oil is always supplied to the meshing portion between the driven shaft gear 26 and the driving gear 27. ing.

  Now, in the centrifugal compressor 1 according to the present embodiment, the dry gas seal 30 from the impeller 11 side to the side opposite to the impeller 11 of the dry gas seal 30, that is, in the bearing housing 29 between the dry gas seal 30 and the bearing 22. A cooling recovery mechanism 33 is provided for recovering the liquefied process fluid (here, the heat medium) by cooling and liquefying the gas phase process fluid (here, the heat medium) that has passed through and leaked into the bearing housing 29. .

  As shown in FIG. 2, in the present embodiment, the cooling recovery mechanism 33 is provided in the cooling recovery mechanism housing 34 provided on the opposite side of the dry gas seal 30 from the impeller 11, the cooling recovery mechanism housing 34, Cooling fins 35 provided so as to surround the periphery of the impeller rotary shaft 21, a cooling fluid passage 36 formed in the cooling recovery mechanism housing 34 for passing the cooling fluid for cooling the cooling fins 35, and the cooling recovery mechanism housing 34, and a recovery hole 37 for recovering a process fluid (here, a heat medium) cooled and liquefied by the cooling fin 35. In FIG. 2, the detailed structure of the dry gas seal (non-contact type seal) 30 is omitted.

  The cooling recovery mechanism housing 34 is provided in close contact with the dry gas seal 30 (more specifically, the protrusion 20a formed inside the bearing housing 29). An O-ring 38 as a packing material is provided on the contact surface of the cooling recovery mechanism housing 34 with the dry gas seal 30 (protrusion 20a), and the cooling recovery mechanism housing 34 is opposed to the dry gas seal 30 (protrusion 20a). And airtight.

  The cooling fin 35 is provided at the end of the cooling recovery mechanism housing 34 opposite to the dry seal 30 and is provided so as to surround the periphery of the impeller rotary shaft 21. Here, although the three cooling fins 35 were formed along the axial direction of the impeller rotating shaft 21, the number of the cooling fins 35 is not limited to this. The distance between the cooling fin 35 and the impeller rotary shaft 21 is preferably as small as possible so that the process fluid (here, the heat medium) does not leak into the bearing housing 29.

  The cooling fluid flow path 36 is desirably formed in the vicinity of the cooling fin 35 in order to efficiently cool the cooling fin 35. In the present embodiment, the lubricating oil cooled by the oil cooler 44 is used as the cooling fluid that passes through the cooling fluid flow path 36. By using lubricating oil as the cooling fluid, the structure of the cooling recovery mechanism 33 is simplified as compared with the case where other cooling fluid such as cooling water is introduced from outside the system.

  In the cooling recovery mechanism 33, a space 34 a surrounded by the cooling recovery mechanism housing 34 is formed between the dry gas seal 30 and the cooling fin 35, and the process fluid (here, cooled to the liquid by cooling with the cooling fin 35) Then, the heat medium) is guided below the space 34a. Although not shown, a hole for passing a process fluid (in this case, a heat medium) that is a liquid is formed in the lower portion of the cooling fin 35, and the recovered process fluid (here, Then, the heat medium) is guided to the space 34a through this hole. A recovery hole 37 is formed in the cooling recovery mechanism housing 34 below the space 34 a so as to penetrate the cooling recovery mechanism housing 34.

  As shown in FIGS. 1 and 2, the recovery hole 37 is connected to a heat medium recovery line 39 extending from the recovery hole 37 to the liquid receiver 103. The heat medium recovery line 39 is provided with a heat medium recovery container 39 a for storing the heat medium recovered from the recovery hole 37, and the heat medium recovery line 39 between the heat medium recovery container 39 a and the liquid receiver 103 has two A direction valve 39b is provided. The two-way valve 39 b is opened when the centrifugal compressor 1 is stopped, and returns the heat medium stored in the heat medium recovery container 39 a to the liquid receiver 103. The heat medium recovery line 39 branches on the upstream side of the heat medium recovery container 39a, and one is connected to the recovery hole 37 of the cooling recovery mechanism 33 and the other is connected to the separation recovery mechanism 45.

  By providing the cooling recovery mechanism 33, the process fluid (here, the heat medium) that has passed through the dry gas seal 30 is cooled to become a liquid and is recovered in the heat medium recovery container 39a through the heat medium recovery line 39. Intrusion into the bearing housing 29 can be suppressed. However, since the amount of the process fluid (here, the heat medium) entering the bearing housing 29 is not completely zero, in the present embodiment, the lubricating oil is further heated in the lubricating oil circulation line 40. A separation / recovery mechanism 45 is provided for vaporizing and separating the process fluid (here, the heat medium) dissolved in the lubricating oil and collecting the vaporized process fluid (here, the heat medium).

  The separation / recovery mechanism 45 is provided in the lubricating oil circulation line 40 between the two-way valve 41 and the lubricating oil container 42. The separation / recovery mechanism 45 requires a means for heating the lubricating oil. In the present embodiment, the separation / recovery mechanism 45 exchanges heat between the high-temperature heat medium compressed by the centrifugal compressor 1 and the lubricating oil. Thus, the lubricating oil is heated. FIG. 1 shows a case where the heat medium circulation line 102 on the downstream side of the condenser 101 is passed through the separation / recovery mechanism 45 to exchange heat between the heat medium and the lubricating oil on the downstream side of the condenser 101. However, the heat exchange may be performed with any position of the heat medium as long as it is downstream of the centrifugal compressor 1 and upstream of the expansion valve.

  When the lubricating oil is heated by the separation / recovery mechanism 45, the heat medium that has become a gas passes through the heat medium recovery line 39 and is recovered in the heat medium recovery container 39a. The heat medium that has become a gas is naturally cooled while passing through the heat medium recovery line 39 to become a liquid, and the heat medium that has become a liquid is recovered in the heat medium recovery container 39a.

  The operation of the present embodiment will be described.

  In the centrifugal compressor 1 according to the present embodiment, the gas phase process fluid leaked into the bearing housing 29 from the impeller 11 side through the dry gas seal 30 on the opposite side of the impeller 11 of the dry gas seal 30. A cooling recovery mechanism 33 is provided for recovering the liquefied process fluid by cooling and liquefying.

  By providing the cooling recovery mechanism 33, it is possible to liquefy and recover the gas phase process fluid that has leaked into the bearing housing 29 from a slight gap in the dry gas seal 30, and the process fluid can be collected into the bearing housing 29. Intrusion can be suppressed. Therefore, even when a process fluid that is very compatible with the lubricating oil is used, deterioration of the lubricating oil performance can be suppressed, and a process fluid that is highly erodible to the elastomer material can be used. Even if it exists, it can suppress that sealing materials, such as packing used for the bearing housing 29, deteriorate and a malfunction generate | occur | produces.

  Further, in the present embodiment, the lubricating oil is provided with the separation and recovery mechanism 45 that heats the lubricating oil and vaporizes and separates the process fluid dissolved in the lubricating oil, and collects the vaporized process fluid. Even when the process fluid is dissolved, the process fluid can be quickly recovered, and deterioration of the performance of the lubricating oil and adverse effects on the sealing material such as packing can be suppressed.

  Furthermore, in the present embodiment, since the heat medium compressed by the centrifugal compressor 1 and heated to a high temperature is used as the heat source of the separation and recovery mechanism 45, it is not necessary to separately provide a heating means or the like in the separation and recovery mechanism 45. It is low cost and energy saving can be improved.

  Next, another embodiment of the present invention will be described.

  The centrifugal compressor 51 shown in FIGS. 3 and 4 has basically the same configuration as the centrifugal compressor 1 described with reference to FIGS.

  As shown in FIGS. 3 and 4, the cooling recovery mechanism 52 has basically the same structure as the cooling recovery mechanism 33 described in FIG. 2, but the direction of the cooling fins 35 is different.

  That is, in the cooling recovery mechanism 33 described with reference to FIG. 2, the cooling fins 35 are formed so as to extend in a direction perpendicular to the axial direction of the impeller rotating shaft 21, and a plurality of cooling fins 35 are aligned in the axial direction. However, in the cooling recovery mechanism 52, the cooling fins 35 are formed so as to extend parallel to the axial direction of the impeller rotating shaft 21, and a plurality (here, four) cooling fins 35 are formed coaxially with the impeller rotating shaft 21. Is done. Each cooling fin 35 is provided so as to protrude into the space 34a from the inner wall of the cooling recovery mechanism housing 34 toward the dry gas seal 30 side.

  As shown in FIG. 4, a notch 35a is formed in the lower portion of each cooling fin 35, and each cooling fin 35 is formed in a C shape that is rotated 90 degrees to the right in a sectional view. The process fluid (here, the heat medium) that is cooled by the cooling fins 35 to become a liquid passes through the notch 35a and is guided to the lower part (recovery hole 37) of the space 34a.

  In the cooling recovery mechanism 52, an end portion of the cooling recovery mechanism housing 34 opposite to the dry gas seal 30 is provided so as to surround the periphery of the impeller rotating shaft 21, and the cooling recovery mechanism at this end portion is provided. It is desirable that the distance between the housing 34 and the impeller rotary shaft 21 be as small as possible so that the process fluid (here, the heat medium) does not leak into the bearing housing 29.

  As described above, even when the cooling fin 35 is formed so as to extend in parallel to the axial direction of the impeller rotary shaft 21, as with the centrifugal compressor 1 described above, the slight gap in the dry gas seal 30 is used. The gas phase process fluid that has leaked into the bearing housing 29 can be liquefied and recovered, and entry of the process fluid into the bearing housing 29 can be suppressed.

  Further, in the centrifugal compressor 51, even when the width of the entire cooling recovery mechanism 52 (that is, the width of the cooling recovery mechanism housing 34) is reduced, many cooling fins 35 can be provided. In addition, the cooling recovery mechanism 52 can be downsized while maintaining a sufficient cooling effect, which contributes to downsizing of the centrifugal compressor 51.

  The present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the spirit of the present invention.

  For example, in the above embodiment, the case where the centrifugal compressor 1 is applied to a high-temperature heat pump has been described. However, the centrifugal compressor 1 of the present invention is not limited to a high-temperature heat pump, and is widely applied to all types of heat pumps such as a refrigerator. It can also be widely applied to chemical plants other than heat pumps.

  In the above embodiment, the case where the dry gas seal 30 is used as the non-contact type seal has been described. However, the present invention is not limited to this, and a non-contact type seal other than the dry gas seal may be used.

  Furthermore, in the above embodiment, the case where the cooling recovery mechanism 33 having the structure shown in FIG. 2 or the cooling recovery mechanism 52 having the structure shown in FIGS. 3 and 4 is used has been described. The structure is not limited, and any structure may be used as long as the gas-phase process fluid can be cooled and recovered as a liquid.

DESCRIPTION OF SYMBOLS 1 Centrifugal compressor 11 Impeller 21 Impeller rotating shaft 29 Bearing housing 30 Dry gas seal (non-contact seal)
33 Cooling recovery mechanism 100 Heat pump

Claims (3)

A centrifugal compressor having a non-contact seal in a bearing housing that houses an impeller rotary shaft and compressing a gas phase process fluid,
On the opposite side of the impeller of the non-contact type seal, the gas phase process fluid leaked into the bearing housing through the non-contact type seal from the impeller side is cooled and liquefied and liquefied. A cooling recovery mechanism for recovering the process fluid is provided ;
The cooling recovery mechanism is
A cooling recovery mechanism housing provided on the opposite side of the impeller of the non-contact seal;
A cooling fin provided on the cooling recovery mechanism housing and surrounding the impeller rotation shaft;
A cooling fluid passage formed in the cooling recovery mechanism housing and for passing a cooling fluid for cooling the cooling fin;
A centrifugal compressor , comprising: a recovery hole that is formed vertically below the cooling recovery mechanism housing and recovers the process fluid cooled and liquefied by the cooling fins . A lubricating oil circulation line for recovering the lubricating oil in the bearing housing and supplying the lubricating oil again into the bearing housing;
The centrifuge according to claim 1, wherein the lubricating oil circulation line is provided with a separation and recovery mechanism for heating and lubricating the lubricating oil to vaporize and separate the process fluid dissolved in the lubricating oil and recovering the vaporized process fluid. Compressor. An evaporator that exchanges heat with a high-temperature heat source to evaporate the heat medium, a compressor that compresses the heat medium evaporated by the evaporator, and a low-temperature heat source that compresses the heat medium compressed by the compressor In a heat pump comprising a condenser that exchanges heat and condenses the heat medium, and an expansion valve that expands the heat medium condensed in the condenser and supplies the expansion medium to the evaporator,
As the compressor, the centrifugal compressor according to claim 2 is used,
The heat recovery pump is configured to heat the lubricating oil by exchanging heat between the heat medium compressed by the centrifugal compressor and the lubricating oil.

Images