JP6448936B2 - Oil recovery device for turbo refrigerator - Google Patents

Description

  The present invention relates to an oil recovery device for a centrifugal chiller in which compressor lubricating oil that has flowed out to the refrigeration cycle can be recovered in an oil tank of a lubricating oil system via an ejector.

  In a centrifugal chiller, a bearing that supports the rotating shaft (motor shaft and / or impeller shaft) of a compressor (turbo compressor) is cooled and lubricated with lubricating oil, and the lubricating oil is compressed. It is equipped with a lubricating oil system that circulates to the cooling and lubricating parts of the machine. This lubricating oil system is generally discharged from an oil tank that stores a certain amount of lubricating oil, an oil pump and oil supply passage that supplies the lubricating oil to the cooling and lubricating parts of the compressor, and a cooling and lubricating part of the compressor. The oil drainage path collects the oil in the oil tank, and an oil cooler is provided if necessary.

  On the other hand, the lubricating oil used for compressor lubrication has compatibility with the refrigerant filled in the refrigeration cycle, and flows out to the refrigeration cycle side by dissolving in contact with the refrigerant in the compressor. . The lubricating oil that has flowed out to the refrigeration cycle reaches the evaporator and remains in the evaporator, thereby hindering heat exchange between the refrigerant and the medium to be cooled, lowering the evaporation performance, and reducing the cycle efficiency. For this reason, as shown in Patent Documents 1 and 2, the lubricating oil that has flowed out to the refrigeration cycle side is recovered from the evaporator to the oil tank of the lubricating oil system via the ejector.

  Patent Document 1 discloses a configuration in which lubricating oil is sucked from an evaporator via an ejector that uses high-pressure gas refrigerant extracted from a condenser as a driving fluid and is collected in an oil tank of a lubricating oil system. . Further, in Patent Document 2, the lubricating oil is recovered from the evaporator to the oil recovery unit, where the lubricating oil is heated by the heater to evaporate the refrigerant and return to the refrigeration cycle side. There is disclosed a system in which oil discharged from a pump is sucked by an ejector using a driving fluid and collected in an oil tank.

Japanese Patent Application Laid-Open No. 10-300290 Japanese Patent No. 2827801

  As described above, the lubricating oil that has flowed out to the refrigeration cycle reaches the evaporator together with the refrigerant, and remains in the evaporator without being evaporated as it is. Since this lubricating oil has a specific gravity smaller than that of the refrigerant, a dense lubricating oil layer is formed on the upper layer of the liquid refrigerant and stays there, so that it is sucked with an ejector and collected in an oil tank. However, the lubricating oil recovered from the evaporator contains a refrigerant, and if it is recovered in the oil tank as it is, the clay of the lubricating oil decreases due to the mixing of the refrigerant, and if the amount increases, there is a concern that foaming will occur. This can cause poor lubrication, tripping due to a decrease in the oil supply differential pressure, and cavitation of the oil pump.

Therefore, as shown in Patent Document 2, the lubricating oil collected in the oil collector is heated, and the lubricating oil separated from the refrigerant is sucked by the ejector and collected in the oil tank. However, in the one shown in Patent Document 2, an oil recovery device is provided on the suction side of the ejector, and the refrigerant recovered from the evaporator is heated to separate the refrigerant so that the refrigerant is not mixed in the subsequent process. The oil discharged from the oil pump is used as the driving fluid, and a certain amount of lubricating oil is retained in the oil recovery unit regardless of whether the ejector is driven. Oil must be filled, and the capacity of the oil pump must be increased to a capacity that discharges the total amount of oil that is supplied to the compressor cooling / lubrication area and the oil that drives the ejector. There was a problem such as not becoming.

The present invention has been made in view of such circumstances, and does not need to be filled with an excessive amount of lubricating oil. Even if a high-pressure gas refrigerant is used as a drive fluid for the ejector, the refrigerant is reliably separated. An object of the present invention is to provide an oil recovery device for a turbo chiller that can recover the lubricating oil to the lubricating oil system and reduce the capacity of the oil pump of the lubricating oil system.

In order to solve the above-described problems, the turbo chiller oil recovery apparatus of the present invention employs the following means.
That is, an oil recovery device for a turbo chiller according to the present invention includes an ejector that uses a high-pressure gas refrigerant extracted from a condenser as a driving fluid for compressor lubricating oil mixed into the refrigerant and flowing out to the refrigeration cycle side. An oil recovery device for a turbo chiller that is sucked from an evaporator and can be recovered in an oil tank of a lubricating oil system, and heats the lubricating oil including a refrigerant on a discharge side of the ejector, An oil recovery device for separating the refrigerant from the lubricating oil is provided, and a refrigerant return circuit for returning the refrigerant gas separated by the oil recovery device to the refrigeration cycle side is provided.

According to the present invention, there is provided an oil recovery device for a turbo refrigerator in which the lubricating oil for a compressor that has flowed out to the refrigeration cycle side can be recovered in an oil tank via an ejector that uses a high-pressure gas refrigerant as a driving fluid. In addition, an oil recovery device that heats the lubricating oil containing refrigerant on the discharge side of the ejector and separates the refrigerant from the lubricating oil is provided, and the refrigerant return that returns the refrigerant gas separated by the oil recovery device to the refrigeration cycle side Since the circuit is provided, the oil recovery device provided on the discharge side of the ejector can be configured to directly suck the lubricating oil containing the refrigerant from the refrigeration cycle side through the ejector using the high-pressure gas refrigerant as the driving fluid. Lubricating oil with a high mixing ratio of refrigerant can be intensively heated to efficiently separate the refrigerant, and the lubricating oil with reduced refrigerant mixing amount can be recovered in the oil tank, while the refrigerant separated from the lubricating oil Gas It can be returned promptly to the refrigeration cycle side by the medium returning circuit. Accordingly, it is possible to eliminate the concern that the amount of mixed refrigerant increases and the clay of the lubricating oil is lowered or foamed, leading to poor lubrication, tripping, and cavitation of the oil pump. In addition, the amount of lubricating oil filled can be reduced by an amount corresponding to the lubricating oil held in the oil collecting device, compared with the case where an oil collecting device is provided on the suction side of the ejector. By making the oil pump dedicated to oil supply, the capacity and power can be reduced.

  Furthermore, the oil recovery device of the turbo chiller according to the present invention is a heater that heats the lubricating oil recovered by the ejector from the refrigeration cycle side in the oil recovery device of the turbo chiller. And the separator which isolate | separates the refrigerant | coolant in the lubricating oil is set as the structure integrated or separated.

  According to the present invention, in the oil recovery apparatus, the heater that heats the lubricating oil recovered by the ejector from the refrigeration cycle side and the separator that separates the refrigerant in the lubricating oil are integrated or separated. Therefore, the function of heating the lubricating oil recovered from the refrigeration cycle side and the function of separating the refrigerant in the lubricating oil have two functions: the specification of the heater, that is, the type of heating source and its function Depending on the configuration, the oil recovery device can be configured as an integral or separate unit with the separator, and in either case, the lubricant recovered from the refrigeration cycle side is heated on the discharge side of the ejector. Thus, the refrigerant can be separated, and the separated refrigerant can be recovered in the refrigeration cycle side, and the lubricating oil can be recovered in the oil tank of the lubricating oil system. Therefore, lubricating oil with a high mixing ratio of refrigerant is concentratedly heated by a heater on the discharge side of the ejector, the refrigerant is efficiently separated by a separator, and each is reliably recovered in the refrigeration cycle side and the oil tank. be able to.

  Furthermore, the oil recovery device for a turbo chiller according to the present invention is the oil recovery device for any one of the above-described turbo chillers, in which the oil recovery device is recovered from the refrigeration cycle side through the ejector. It is characterized by comprising a heating / separator that mixes high-temperature oil discharged from the lubricating part of the compressor and heats the lubricating oil containing the refrigerant to separate the refrigerant.

  According to the present invention, the oil recovery device mixes the high-temperature oil discharged from the lubricating portion of the compressor into the lubricating oil recovered from the refrigeration cycle side through the ejector, and heats the lubricating oil including the refrigerant. Because it is composed of a heating / separator that separates the refrigerant, the high-temperature oil discharged from the lubrication part of the compressor is mixed with the lubricating oil containing the refrigerant recovered from the refrigeration cycle side as an oil recovery device. It is only necessary to provide a heating / separator that heats and separates the refrigerant. Therefore, it is not necessary to prepare a special heating means, the configuration of the oil recovery device can be simplified, and heat dissipation loss can be eliminated. Can do.

  Furthermore, the oil recovery device for a turbo chiller according to the present invention is the oil recovery device for a turbo chiller described above, wherein the oil recovery device is a high-temperature oil discharged from a lubrication part of an electric heater or the compressor or the refrigeration. A structure in which the heater, which is a heat transfer tube through which either high-pressure gas refrigerant or high-pressure liquid refrigerant extracted from the cycle side is circulated, is provided in the separator, and the heater and the separator are integrated; It is characterized by being.

  According to the present invention, the oil recovery device is a heat transfer tube in which either high-temperature oil discharged from the lubrication part of the electric heater or the compressor or high-pressure gas refrigerant or high-pressure liquid refrigerant extracted from the refrigeration cycle side is circulated. Since the heater is provided in the separator and the heater and the separator are integrated, the separator is provided with the lubricant recovered from the refrigeration cycle side on the discharge side of the ejector. The refrigerant is integrated by introducing it into the inside and heating it with an electric heater or a heater in which high-temperature oil or high-pressure gas refrigerant or high-pressure liquid refrigerant is circulated. It is possible to efficiently separate by the heated heater / separator and return the refrigerant and the lubricating oil to the refrigeration cycle side and the oil tank, respectively. Therefore, heat is concentrated in a heating / separator that integrates lubricating oil with a high mixing ratio of refrigerant on the discharge side of the ejector, efficiently separating the refrigerant, and ensuring that each is in the refrigeration cycle side and oil tank. Can be recovered.

  Further, the oil recovery device for a turbo chiller according to the present invention is the oil recovery device for the turbo chiller described above, wherein the oil recovery device is extracted from high-temperature oil discharged from a lubrication site of the compressor or the refrigeration cycle. The high-pressure gas refrigerant or the high-pressure liquid refrigerant, and the heater that is a double-tube heat exchanger that exchanges heat between the refrigeration cycle side and the lubricating oil recovered by the ejector, and the downstream side thereof And the separator for separating the refrigerant from the lubricating oil heated in the double-tube heat exchanger, wherein the heater and the separator are separated. And

  According to the present invention, the oil recovery device recovers either the high-temperature oil discharged from the lubrication part of the compressor or the high-pressure gas refrigerant or the high-pressure liquid refrigerant extracted from the refrigeration cycle and the ejector from the refrigeration cycle side. A heat exchanger for exchanging heat with the lubricating oil, and a separator provided on the downstream side thereof for separating the refrigerant from the lubricating oil heated in the double pipe heat exchanger Since the heater and the separator are separated, the lubricating oil containing the refrigerant recovered from the refrigeration cycle side is supplied to the double tube heat exchanger provided on the discharge side of the ejector. After introducing and heating heat exchanged with either high-temperature oil or high-pressure gas refrigerant or high-pressure liquid refrigerant discharged from the lubrication site inside, by introducing into the separator provided on the downstream side, Out of lubricating oil Medium was separated, it can be returned refrigerant and lubricating oil in each refrigeration cycle side and the oil tank. Therefore, lubricating oil with a high mixing ratio of refrigerant on the discharge side of the ejector is intensively heated by an oil recovery device in which a heater and a separator are separated to efficiently separate the refrigerant, and each is reliably refrigerated. It can be recovered in the cycle side and in the oil tank.

  In the turbo refrigerator oil recovery apparatus according to the present invention, in any one of the above-described turbo refrigerator oil recovery apparatuses, the separator is shared by the oil tank.

  According to the present invention, since the separator is shared by the oil tank, the lubricating oil recovered by the ejector from the refrigeration cycle side is discharged from the lubrication site by a double pipe heat exchanger or the like that is a heater. Heat is exchanged with either high-temperature oil or high-pressure gas refrigerant or high-pressure liquid refrigerant and heated, and then introduced into the oil tank on the downstream side to separate the refrigerant from the lubricating oil, and the lubricating oil is directly put into the oil tank. In addition to being able to recover, the separated refrigerant can be returned to the refrigeration cycle side. Thus, by combining an oil tank as a refrigerant separator, an oil recovery apparatus that separates and recovers refrigerant from lubricating oil can be used. The configuration can be simplified and the cost can be reduced.

  Furthermore, an oil recovery device for a turbo chiller according to the present invention is the oil recovery device for any one of the above-described turbo chillers, wherein the ejector is activated / deactivated in a path for supplying the drive fluid to the ejector. A control valve is provided.

According to the present invention, since the control valve for operating / disabling the ejector is provided in the system for supplying the drive fluid to the ejector, the control valve is controlled to open and close according to the operating condition, and driven to the ejector. By supplying or stopping the high-pressure gas refrigerant as the fluid, the ejector can be turned on and off easily by turning the ejector on and off. At this time, the oil recovery device provided on the discharge side of the ejector Lubricating oil does not flow in from the refrigeration cycle side and is not held, so that the amount of lubricating oil filled in each system can be reduced.

According to the present invention, even if the lubricating oil containing the refrigerant is directly sucked from the refrigeration cycle side through the ejector using the high-pressure gas refrigerant as the driving fluid, the refrigerant is mixed in the oil recovery device provided on the discharge side of the ejector. It is possible to intensively heat a high proportion of lubricating oil and efficiently separate the refrigerant, and to collect the lubricating oil with a reduced amount of refrigerant mixed in the oil tank, while the refrigerant gas separated from the lubricating oil is used as the refrigerant Since the return circuit can quickly return to the refrigeration cycle side, the amount of refrigerant mixed in increases, eliminating the concerns about lubrication failure, tripping, oil pump cavitation, etc. can do. In addition, the amount of lubricating oil filled can be reduced by an amount corresponding to the lubricating oil held in the oil collecting device, compared with the case where an oil collecting device is provided on the suction side of the ejector. By making the oil pump dedicated to oil supply, the capacity and power can be reduced.

It is a lineblock diagram of the oil recovery device of the turbo refrigerator concerning a 1st embodiment of the present invention. It is a block diagram of the oil recovery apparatus of the turbo refrigerator which concerns on 2nd Embodiment of this invention. It is a block diagram of the oil recovery apparatus of the turbo refrigerator which concerns on 3rd Embodiment of this invention. It is a block diagram of the modification of the oil recovery apparatus which concerns on the said 3rd Embodiment. It is a block diagram of the oil recovery apparatus of the turbo refrigerator which concerns on 4th Embodiment of this invention.

Embodiments according to the present invention will be described below with reference to the drawings.
[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a schematic configuration diagram (system diagram) of an oil recovery device for a turbo chiller according to a first embodiment of the present invention.
The turbo refrigerator 1 includes a closed cycle refrigeration cycle 7 configured by connecting a turbo compressor (compressor) 2, a condenser 3, a decompression device 4, and an evaporator 5 sequentially through a refrigerant pipe 6. Yes. This refrigeration cycle 7 is well known, and is filled with a predetermined amount of refrigerant in the cycle 7 and circulated through the compressor 2.

  On the other hand, the turbo compressor (compressor) 2 includes an impeller 8, and the impeller 8 is driven by a motor 9 with a motor shaft 10 and / or an impeller shaft 11 (in the case of a compressor with a direct connection structure, a motor shaft and an impeller shaft). , And a low-pressure refrigerant gas is sucked, centrifugally compressed, and discharged as a high-temperature and high-pressure refrigerant gas. The motor shaft 10 and / or the impeller shaft 11 of the compressor 2 are rotatably supported in the housing 12 via a plurality of sets of bearings (not shown), and the power is transmitted via the speed increasing gear train 13. Are combined to be.

  The bearing and the speed increasing gear train 13 are cooled and lubricated through a lubricating oil 14. A predetermined amount of the lubricating oil 14 is stored in the oil tank 15, and is supplied to the bearing and the speed increasing gear train 13 which are lubrication parts via the oil pump 16 and the oil supply system passage 17, and the bearing, the speed increasing gear train 13 and the like. After being cooled and lubricated, a lubricating oil system path (lubricating oil system) 19 is formed so as to return to the oil tank 15 through a predetermined oil draining system path 18 from there. Although the oil tank 15 has been described as an example where it is provided separately, the oil tank 15 may be provided integrally in the turbo compressor 2.

  The lubricating oil 14 is compatible with the refrigerant filled in the refrigeration cycle 7, and is mixed (dissolved) in the refrigerant by contacting the refrigerant in the compressor 2, and flows out to the refrigeration cycle 7 side. . This lubricating oil 14 passes through the condenser 3 and the decompression device 4 together with the refrigerant to reach the evaporator 5 and does not evaporate. Therefore, the lubricating oil 14 remains in the evaporator 5 and has a specific gravity smaller than that of the refrigerant. A high-density layer is formed on the upper layer and stays there.

  When the lubricating oil 14 stays in the evaporator 5, the heat exchange between the refrigerant and the medium to be cooled is hindered, and not only the evaporation performance is lowered, but also the amount corresponding to the amount of oil flowing out and staying on the refrigeration cycle 7 side. This means that the amount of oil in the lubricating oil system passage 19 is reduced and the oil becomes insufficient. Therefore, it is necessary to recover the lubricating oil that has flowed out to the refrigeration cycle 7 side to the lubricating oil system path 19 side, and an oil recovery system path 20 that performs the function is provided.

As described above, the oil recovery path 20 sucks the lubricating oil 14 staying in the upper layer of the liquid refrigerant in the evaporator 5 and recovers it into the oil tank 15 of the lubricating oil path 19. The refrigerant sucked together with the lubricating oil 14 from the evaporator 5 is separated and can be recovered in the oil tank 15 in a state where the amount of refrigerant mixed is reduced. The oil recovery system 20 includes an ejector 21 for sucking the lubricating oil 14 staying in the evaporator 5.

  The ejector 21 includes a nozzle, a diffuser, a suction chamber, and the like. The ejector 21 entrains and mixes the suction fluid in the suction chamber using a driving force generated by the flow of high-pressure fluid (driving fluid) ejected from the nozzle. The high-pressure gas refrigerant extracted from the condenser 3 as a driving fluid can be introduced into the nozzle via the pipe 22 and sucks lubricating oil from the evaporator 5. A piping 23 is connected to the suction chamber.

  On the discharge side of the ejector 21, that is, on the downstream side of the diffuser, the refrigerant mixed in the lubricating oil 14 is heated and separated, and the lubricating oil in which the mixing ratio of the refrigerant is reduced is collected on the lubricating oil path 19 side. In addition, an oil recovery device 25 for returning the separated refrigerant to the refrigeration cycle 7 side is connected via the discharge pipe 24. Further, the refrigerant is separated from the oil recovery device 25 and mixed therein. An oil return pipe 26 for returning the reduced amount of the lubricating oil 14 into the oil tank 15 and a refrigerant return pipe (refrigerant return circuit) 27 for returning the separated refrigerant to the refrigeration cycle 7 side are connected. .

  The other end side of the refrigerant return pipe (refrigerant return circuit) 27 is connected to the evaporator 5 or the refrigerant suction pipe extending from the evaporator 5 to the compressor 2. The refrigerant return pipe 27 is connected to the oil tank 15 and has a function as a pressure equalizing pipe for maintaining the pressure in the oil tank 15 at a low pressure.

  As shown in FIG. 1, the oil recovery device 25 of the present embodiment includes a lubricating part of the compressor 2 in the lubricating oil containing the refrigerant recovered from the evaporator 5 on the refrigeration cycle 7 side through the ejector 21. It comprises a heating / separator 28 for separating the refrigerant by heating the lubricating oil containing the refrigerant by mixing the high-temperature oil discharged from the oil through the oil discharge system 18, and lubricating the turbo compressor 2. It is supposed that the lubricating oil containing the refrigerant is heated by using high-temperature exhaust oil whose temperature has been raised by cooling and lubricating the part as a heat source, and the refrigerant is separated.

With the configuration described above, according to the present embodiment, the following operational effects can be obtained.
In the turbo chiller 1, when the turbo compressor 2 is started and the refrigeration operation is started, the refrigerant compressed by the turbo compressor 2 passes through the condenser 3, the decompression device 4, the evaporator 5 and the refrigeration cycle 7 in sequence. It circulates and performs the required cooling action. On the other hand, the lubricating oil 14 that circulates through the lubricating oil passage 19 having compatibility with the refrigerant contacts and enters the refrigerant in the turbo compressor 2 and flows out to the refrigeration cycle 7 side. Circulates in the refrigeration cycle 7 together with the refrigerant, reaches the evaporator 5, and forms a high-density layer on the upper layer of the liquid refrigerant and stays therein.

The oil recovery system path 20 sucks the lubricating oil 14 staying in the evaporator 5 through an ejector 21 using the high-pressure gas refrigerant extracted from the condenser 3 as a driving fluid, and is connected to the discharge side thereof. It is introduced into a heating / separator 28 constituting the oil recovery device 25 through the discharge pipe 24.
The heating / separator 28 is supplied with oil from the oil tank 15 through the oil pump 16 and the oil supply path 17 to the bearing or the speed increasing gear train 13 which is a lubrication part of the turbo compressor 2. After the oil is cooled and lubricated, the high-temperature lubricating oil 14 that is returned to the oil tank 15 through the predetermined oil drain path 18 is introduced.

  The temperature of the lubricating oil 14 discharged from the oil draining path 18 is raised by cooling and lubricating the lubricated portion of the turbo compressor 2, and the lubricating oil 14 is supplied to the heating / separator 28 of the oil recovery device 25. Low temperature lubricating oil recovered from the refrigeration cycle 7 side using the high temperature lubricating oil 14 discharged from the lubrication site as a heating source by mixing in the lubricating oil 14 containing the refrigerant recovered from the refrigeration cycle 7 side. 14 can be heated to evaporate and separate the refrigerant. The separated refrigerant can be returned to the refrigeration cycle 7 (evaporator 5) side through the refrigerant return pipe (refrigerant return circuit) 27, and lubricating oil with a reduced refrigerant mixing ratio can be supplied to the oil return pipe 26. It can be recovered in the oil tank 15 of the lubricating oil path 19 via

  Thus, according to the oil recovery system 20 of the present embodiment, the lubricating oil 14 containing the refrigerant can be directly sucked from the refrigeration cycle 7 side through the ejector 21 using the high-pressure gas refrigerant as the driving fluid. The oil recovery device 25 provided on the discharge side of the ejector 21 intensively heats the lubricating oil with a high mixing ratio of the refrigerant to efficiently separate the refrigerant, and the lubricating oil with the reduced mixing amount of the refrigerant is supplied to the oil tank 15. On the other hand, since the refrigerant gas separated from the lubricating oil 14 can be quickly returned to the refrigeration cycle 7 side by the refrigerant return circuit 27, the amount of refrigerant mixed increases, and the clay of the lubricating oil decreases. Alternatively, it is possible to eliminate the concern that forming will occur and cause lubrication failure, trip, cavitation of the oil pump 16, and the like.

Moreover, compared with the conventional one provided with the oil recovery device to the suction side of the ejector 21, an amount corresponding to corresponding to the lubricating oil 1 4 to be held in the oil recovery vessel, reducing the loading of the lubricating oil 1 4 In addition, since the oil pump 16 of the lubricating oil path (lubricating oil system) 19 is dedicated to oil supply, the capacity and power can be reduced.

  Further, in the present embodiment, the oil recovery device 25 mixes the high-temperature oil discharged from the lubrication part of the turbo compressor 2 into the lubricating oil recovered by the ejector 21 from the refrigeration cycle 7 side, and includes the refrigerant. Since it comprises the heating / separator 28 that heats the lubricating oil and separates the refrigerant, the lubricating oil 14 containing the refrigerant recovered from the refrigeration cycle 7 side by the ejector 21 is used as the oil recovery device 25 as a turbo compressor. It is only necessary to provide a heating / separator 28 that mixes and heats high-temperature oil discharged from the lubrication part 2 and separates the refrigerant, and therefore, it is not necessary to prepare a special heating means, and the oil recovery apparatus The configuration of 25 can be simplified and heat dissipation loss can be eliminated.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.
This embodiment differs in the structure of the oil collection | recovery apparatus 25 with respect to above-described 1st Embodiment. Since other points are the same as those in the first embodiment, description thereof will be omitted.
The oil recovery device 25 of the present embodiment is integrally provided with a heater 29 that heats the lubricating oil 14 in a separator 30 that separates the refrigerant in the lubricating oil 14 recovered by the ejector from the refrigeration cycle side. The heater 29 and the separator 30 are integrated.

  The heater 29 may be an electric heater, or a high-pressure gas refrigerant or a high-pressure liquid refrigerant extracted from the heat transfer pipe through which high-temperature oil discharged from the lubrication part of the turbo compressor 2 is circulated or the refrigeration cycle 7 side. Either a heat transfer pipe or the like that is circulated may be used. Either the high-temperature oil discharged from the lubrication part of the electric heater or the turbo compressor 2, or the high-pressure gas refrigerant or high-pressure liquid refrigerant extracted from the refrigeration cycle 7 side. An oil recovery device 25 in which the heater 29 and the separator 30 are integrated is configured by providing the heater 29 in the separator 30 as a heat transfer tube through which the gas is circulated.

  Also in this embodiment, the lubricating oil 14 containing the refrigerant recovered by the ejector 21 from the refrigeration cycle 7 side is introduced into the separator 30 provided on the discharge side of the ejector 21 and provided therein. Heating is performed by a heater 29 which is an electric heater or a heat transfer tube through which high-temperature oil or high-pressure gas refrigerant or high-pressure liquid refrigerant is circulated, so that the refrigerant is efficiently separated by the integrated heating / separators 29 and 30. Then, the refrigerant and the lubricating oil can be returned to the refrigeration cycle 7 side and the oil tank 15, respectively. Therefore, heat is concentrated in heating / separators 29 and 30 in which lubricating oil with a high mixing ratio of refrigerant is integrated on the discharge side of the ejector 21 to efficiently separate the refrigerant, thereby ensuring that each of the refrigeration cycles 7 Side and oil tank 15 can be collected.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIGS.
This embodiment differs in the structure of the oil collection | recovery apparatus 25 with respect to above-described 1st and 2nd embodiment. Since other points are the same as those in the first embodiment, description thereof will be omitted.
In the oil recovery device 25 of the present embodiment, a heater that heats the lubricating oil 14 containing the refrigerant recovered by the ejector 21 from the refrigeration cycle 7 side is used as a double tube heat exchanger 31 provided on the discharge side of the ejector 21. Yes.

  And, as shown in FIG. 3, a part of the high-pressure gas refrigerant discharged from the turbo compressor 2 via the refrigerant extraction pipe 32 is introduced into the outer pipe of the double pipe heat exchanger 31. Alternatively, as shown in FIG. 4, high-temperature oil discharged from the lubrication site of the turbo compressor 2 through the oil discharge path 18 is introduced and used as a heating source for heating the lubricating oil 14 including the refrigerant. Further, by introducing the lubricating oil 14 containing the refrigerant heated by the double pipe heat exchanger 31 into the oil tank 15A serving as a separator for separating the refrigerant, the refrigerant is separated, and the separated refrigerant is returned to the refrigerant. It is configured to return to the refrigeration cycle 7 side via a pipe (refrigerant return circuit) 27.

  In the above embodiment, the high-pressure gas refrigerant discharged from the turbo compressor 2 or the lubrication part of the turbo compressor 2 is discharged as a heating source for heating the lubricating oil 14 containing the refrigerant in the double pipe heat exchanger 31. However, the high-pressure liquid refrigerant condensed in the condenser 3 may be used. The high-pressure gas refrigerant, the high-pressure liquid refrigerant, or the high-temperature exhaust oil is used as the double-pipe heat exchanger 31. It is only necessary to guide the condenser 3 or the oil tank 15 through the pipes 33 and 34. In the above embodiment, the refrigerant is separated from the lubricating oil 14 containing the refrigerant heated by the double pipe heat exchanger 31 by the separator / oil tank 15 </ b> A, but the refrigerant is separated from the oil tank 15. A configuration may be provided in which a dedicated separator for separation is provided.

  Thus, in the oil recovery apparatus 25, the heater for heating the lubricating oil 14 containing the refrigerant recovered from the refrigeration cycle 7 side is the double-tube heat exchanger 31, and a separator / oil tank that separates the refrigerant separately from the heater. The lubricating oil 14 containing the refrigerant recovered from the refrigeration cycle 7 side is also introduced into the double-pipe heat exchanger 31 by providing 15A or a dedicated separator and separating the heater and the separator. Then, heat is exchanged with either the high-pressure gas refrigerant, high-pressure liquid refrigerant, or high-temperature exhaust oil in the interior, and then heated, and then introduced into the separator / oil tank 15A (or a dedicated separator) provided downstream. Thus, the refrigerant can be separated from the lubricating oil, and the refrigerant and the lubricating oil can be returned to the refrigeration cycle 7 side and the oil tank 15A (15), respectively.

  Therefore, the oil recovery in which the heater having the double-pipe heat exchanger 31 made of the lubricating oil 14 having a high refrigerant mixing ratio on the discharge side of the ejector 21 and the separator / oil tank 15A or a dedicated separator is separated. The apparatus 25 can be heated intensively to efficiently separate the refrigerant, and each can be reliably recovered in the refrigeration cycle 7 side and in the oil tank 15A (15). In particular, the oil tank 15A has a function of separating the refrigerant from the lubricating oil 14 including the refrigerant heated by the double pipe heat exchanger 31, and the oil tank 15A is also used as a separator, so that the refrigerant can be removed from the lubricating oil. The configuration of the oil recovery apparatus 25 that separates and recovers can be simplified and the cost can be reduced.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIG.
The present embodiment differs from the first to third embodiments described above in the configuration of a system path for introducing a driving fluid (high-pressure gas refrigerant) to the ejector 21. Since other points are the same as those in the first embodiment, description thereof will be omitted.
In this embodiment, as shown in FIG. 5, the ejector 21 is activated / deactivated in a pipe (system path) 22 that introduces the high-pressure gas refrigerant extracted from the condenser 3 into the ejector 21 as a driving fluid. A control valve 35 is provided, and the oil recovery operation can be turned on and off by controlling the opening and closing of the control valve 35 according to the operation status.

As described above, the control valve 35 that activates / deactivates the ejector 21 is provided in the pipe (system path) 22 that supplies the ejector 21 with the high-pressure gas refrigerant that is the driving fluid. Accordingly, the control valve 35 is controlled to open and close, and the ejector 21 can be supplied or stopped with the high-pressure gas refrigerant as the driving fluid. Thus, the oil recovery operation can be easily turned on / off by operating / disabling the ejector 21. At this time, the oil recovery device 25 provided on the discharge side of the ejector 21 is supplied with lubricating oil from the refrigeration cycle 7 side. 1 4 is flowed, hold without being is able to reduce the amount of lubricating oil 1 4 to be filled respectively in the lubricating oil pathway 19 and the refrigeration cycle within 7.

  In addition, this invention is not limited to the invention concerning the said embodiment, In the range which does not deviate from the summary, it can change suitably. For example, in the above embodiment, heating of a heater (the heating / separator 28, the heater 29, the double tube heat exchanger 31, etc.) that heats the lubricating oil 14 containing the refrigerant recovered from the refrigeration cycle 7 side by the ejector 21. The source uses high-temperature oil discharged from the lubrication part, electric heater, high-pressure gas refrigerant extracted from the refrigeration cycle 7 side, high-pressure liquid refrigerant, etc., but high temperature discharged from the lubrication part from the viewpoint of heat loss It is preferable to utilize the exhaust heat of the oil. In this case, since exhaust heat may be insufficient, high temperature oil discharged from the lubrication part is used as the main heating source, and another refrigerant or electric heater is used in combination as a sub heating source to supplement it. It is good.

1 Turbo refrigerator 2 Turbo compressor (compressor)
7 Refrigeration cycle 14 Lubricating oil 15 Oil tank 15A Separator oil tank 19 Lubricating oil system 20 Oil recovery system 21 Ejector 22 Piping for supplying driving fluid (system)
25 Oil recovery device 27 Refrigerant return pipe (refrigerant return circuit)
28 Heater / Separator 29 Heater (electric heater, heat transfer tube)
30 Separator 31 Double tube heat exchanger (heater)
35 Control valve

Claims (3)

The lubricating oil for the compressor mixed into the refrigerant and flowing out to the refrigeration cycle side is sucked from the evaporator through an ejector that uses the high-pressure gas refrigerant extracted from the condenser as a driving fluid, and the oil tank of the lubricating oil system An oil recovery device for a turbo chiller that can be recovered by
An oil recovery device is provided on the discharge side of the ejector for heating the lubricating oil containing the refrigerant and separating the refrigerant from the lubricating oil,
A refrigerant return circuit for returning the refrigerant gas separated by the oil recovery device to the refrigeration cycle side is provided ;
The oil recovery device is configured such that a heater for heating the lubricating oil recovered by the ejector from the refrigeration cycle side and a separator for separating the refrigerant in the lubricating oil are separated.
The oil recovery device is either high-temperature oil discharged from a lubrication site of the compressor or high-pressure gas refrigerant or high-pressure liquid refrigerant extracted from the refrigeration cycle, and the ejector recovered from the refrigeration cycle side by the ejector. The heater that is a double-tube heat exchanger that exchanges heat with the lubricating oil, and the separation that is provided downstream thereof and separates the refrigerant from the lubricating oil heated in the double-tube heat exchanger oil recovery apparatus for centrifugal chiller, characterized in that it consists of a vessel. 2. The turbo chiller oil recovery apparatus according to claim 1 , wherein the separator is shared by the oil tank. The oil recovery apparatus for a turbo chiller according to claim 1 or 2 , wherein a control valve that activates / deactivates the ejector is provided in a system for supplying the drive fluid to the ejector. .

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