Grease and refrigeration cycle device using the grease as a lubricant

Abstract

Provided is a lubricating grease and a refrigeration cycle device using the same as a lubricant, which is capable of suppressing a decrease in the function as a lubricant even when the lubricating grease is used in an apparatus provided in a refrigerant circuit in which a refrigerant having a chlorine atom and an olefin bond in a molecule flows. The composition of the lubricating grease used in an apparatus provided in a refrigerant circuit (50) in which a refrigerant having a chlorine atom and an olefin bond in a molecule flows contains fluorine. In a cooling device, the lubricating grease is used as a lubricant in at least one of a first radial contact bearing (162) and a second radial contact bearing (164) of a compressor (100), a driving portion of an inlet guide vane (124) of the compressor (100), and a driving portion of an expansion valve.

Description

Technical Field

[0001] This disclosure relates to a grease and a refrigeration cycle apparatus using the grease as a lubricant, the grease being used in a device provided in a refrigerant circuit for the flow of a refrigerant containing chlorine atoms and olefin bonds within its molecules. Background Technology

[0002] As in Patent Document 1 (Japanese Patent Publication No. 2011-520089), for the sake of environmental protection, refrigerants with low global warming coefficients and containing chlorine atoms and olefin bonds in their molecules are sometimes used in refrigeration cycle devices. Summary of the Invention

[0003] The technical problem that the invention aims to solve

[0004] In addition, grease is sometimes used as a lubricant for various sliding parts of equipment located in the refrigerant circuit that supplies refrigerant flow.

[0005] However, when using refrigerants containing chlorine atoms and olefin bonds within their molecules, if the grease currently used in refrigeration cycle units is used, adverse situations may occur, such as a decrease in the grease's function as a lubricant.

[0006] Technical solutions adopted to solve technical problems

[0007] The first-concept grease is a grease used in equipment located in a refrigerant circuit, which supplies the flow of a refrigerant containing chlorine atoms and olefin bonds within its molecules. The grease contains fluorine.

[0008] In the first viewpoint of the lubricating grease, by using a chemically stable and fluorinated lubricating grease, even when using a refrigerant containing chlorine atoms and olefin bonds within the molecule, it is possible to suppress the decline in the lubricating grease's function as a lubricant.

[0009] Based on the grease of the first viewpoint, the grease of the second viewpoint contains refrigerant R1233zd(E).

[0010] By using the second-viewpoint grease, R1233zd(E) with a low global warming coefficient, zero ozone depletion coefficient, low environmental impact, non-flammability, low toxicity, and safety can be used in refrigerant circuits, and poor sliding of sliding parts of equipment in refrigerant circuits can be suppressed.

[0011] Based on the greases of the first or second viewpoint, the grease of the third viewpoint uses a fluorinated oil as the base oil.

[0012] By using a grease with a base oil containing fluorine, which has high chemical stability, as a base oil, a third-party approach can be adopted to suppress the decline in the grease's function as a lubricant, even when using refrigerants containing chlorine atoms and olefin bonds within the molecule.

[0013] Based on the greases of any of the first to third viewpoints, in the grease of the fourth viewpoint, fluoropolymer is used as a thickener.

[0014] By using a grease with a chemically stable fluoropolymer as a thickener, as described in the fourth viewpoint, the decline in the grease's function as a lubricant can be suppressed even when using refrigerants containing chlorine atoms and olefin bonds within the molecule.

[0015] Based on the grease of any one of the first to fourth viewpoints, in the grease of the fifth viewpoint, the grease is used as a lubricant in at least one of the following: a rolling bearing that provides shaft support for a shaft connected to a motor of a compressor provided in the refrigerant circuit; a drive part for an inlet guide vane provided at the suction port of a compressor provided in the refrigerant circuit; and a drive part for a valve core provided in an expansion valve provided in the refrigerant circuit.

[0016] By using greases with high chemical stability, damage to rolling bearings, inlet guide vanes, expansion valves, etc., can be suppressed even when using refrigerants containing chlorine atoms and olefin bonds within their molecules.

[0017] The sixth viewpoint's refrigeration cycle device includes a refrigerant circuit for the flow of a refrigerant containing chlorine atoms and olefin bonds within its molecules. The refrigerant circuit includes at least a turbo compressor and an expansion valve. The turbo compressor includes inlet guide vanes, a motor, a shaft, an impeller, and rolling bearings. The inlet guide vanes are located at the suction port of the turbo compressor. The shaft is connected to the motor. The impeller is located on the shaft. The rolling bearings support the shaft. The expansion valve includes a valve core and a drive portion of the valve core. In at least one of the rolling bearings of the turbo compressor, the drive portion of the turbo compressor's inlet guide vanes, and the drive portion of the expansion valve, a fluorinated grease is used as a lubricant.

[0018] In the refrigeration cycle device of the sixth viewpoint, even when using refrigerants containing chlorine atoms and olefin bonds within the molecule, damage to rolling bearings, inlet guide vanes, expansion valves, etc., which use grease can be suppressed. Attached Figure Description

[0019] Figure 1 This is a schematic structural diagram of a cooling device according to one embodiment of a refrigeration cycle device.

[0020] Figure 2 yes Figure 1 A schematic cross-sectional view of the compressor used in the cooling system. Detailed Implementation

[0021] Hereinafter, with reference to the accompanying drawings, embodiments of the lubricating grease and the refrigeration circulation device will be described.

[0022] (1) Overview of the cooling system

[0023] Reference Figure 1 The cooling device 10, which uses the grease as a lubricant, will be described below. Figure 1 This is a schematic structural diagram of the cooling device 10.

[0024] The cooling device 10 is an example of a refrigeration cycle device utilizing a vapor compression refrigeration cycle. The cooling device 10 is a device that cools a liquid (heat medium) by exchanging heat with a refrigerant. The liquid cooled by the cooling device 10 is supplied to a user-side device (not shown) for air conditioning, equipment cooling, etc. The liquid used in this embodiment is, for example, water or brine. Examples of brine include aqueous solutions of sodium chloride, calcium chloride, ethylene glycol, and propylene alcohol. Furthermore, the liquid (heat medium) exchanging heat with the refrigerant is not limited to the types illustrated here; any suitable selection is acceptable. In this embodiment, water is used as the liquid (heat medium).

[0025] Furthermore, the type of refrigeration cycle device is not limited to the cooling device 10 that cools liquids. For example, the refrigeration cycle device may also be a device that heats liquids by exchanging heat between the liquid (heat medium) and the refrigerant. In addition, the refrigeration cycle device may also be a device that cools or heats air by exchanging heat between air and the refrigerant instead of a liquid.

[0026] The cooling unit 10 includes a refrigerant circuit 50. The equipment configured in the refrigerant circuit 50 mainly includes a compressor 100, a condenser 20, an expansion valve 30, and an evaporator 40. The refrigerant circuit 50 is constructed by connecting the compressor 100, condenser 20, expansion valve 30, and evaporator 40 via refrigerant piping as follows: The discharge pipe 116 of the compressor 100 (described later) is connected to the inlet of the condenser 20 via refrigerant piping. The outlet of the condenser 20 is connected to the inlet of the evaporator 40 via refrigerant piping. An expansion valve 30 is installed on the refrigerant piping connecting the outlet of the condenser 20 and the inlet of the evaporator 40. The outlet of the evaporator 40 is connected to the suction pipe 114 of the compressor 100 (described later).

[0027] In addition, the equipment configured in the refrigerant circuit 50 is not limited to the compressor 100, condenser 20, expansion valve 30 and evaporator 40, but may also include other equipment commonly used in the refrigerant circuit 50 of a refrigeration cycle unit.

[0028] The refrigerant circuit 50 is filled with a refrigerant containing chlorine atoms and olefin bonds within its molecules. While the type of refrigerant is not limited, refrigerants containing chlorine atoms and olefin bonds within their molecules and filling the refrigerant circuit 50 include, for example, R1233zd(E) (trans-1-chloro-3,3,3-trifluoropropene), R1233xf (2-chloro-3,3,3-trifluoropropene), and R1224yd(Z) ((Z)-1-chloro-2,3,3,3-tetrafluoropropene). The refrigerant filling the refrigerant circuit 50 can be a single-component refrigerant or a mixture of two or more refrigerants. In the cooling device 10 of this embodiment, the monomer of R1233zd(E) is used as the refrigerant.

[0029] In addition, the cooling device 10 includes a controller 60, which controls the operation of various structures of the compressor 100 (inlet guide vane 124, motor 140, magnetic bearing 150, described later), expansion valve 30, and various parts of the cooling device 10.

[0030] When the cooling unit 10 is operating, the refrigerant circulates within the refrigerant circuit 50 to perform a refrigeration cycle. Specifically, when the motor 140 of the compressor 100 is running, the compressor 100 draws in low-pressure gaseous refrigerant from the refrigeration cycle, compresses the drawn-in gaseous refrigerant, and ejects it as high-pressure gaseous refrigerant in the refrigeration cycle. The high-pressure gaseous refrigerant ejected by the compressor 100 is sent to the condenser 20. The high-pressure gaseous refrigerant sent to the condenser 20 releases heat and condenses in the condenser 20, becoming high-pressure liquid refrigerant. The refrigerant condensed in the condenser 20 is sent to the evaporator 40 through the expansion valve 30. In addition, the high-pressure liquid refrigerant flowing from the condenser 20 toward the evaporator 40 is depressurized when passing through the expansion valve 30, becoming low-pressure gaseous two-phase refrigerant. The low-pressure gaseous two-phase refrigerant flowing into the evaporator 40 absorbs heat from the liquid (heat medium) supplied to the evaporator 40 and evaporates, becoming low-pressure gaseous refrigerant. In the evaporator 40, the refrigerant absorbs heat from the liquid, thereby cooling the liquid. The liquid cooled in the evaporator 40 is supplied to a utilization-side device (not shown) that utilizes the cooled liquid. On the other hand, the gaseous refrigerant evaporated in the evaporator 40 is drawn into the compressor 100 and compressed again.

[0031] (2) Detailed structure of the cooling device

[0032] (2-1) Compressor

[0033] The compressor 100 is a device that draws in low-pressure gaseous refrigerant from the refrigeration cycle, compresses the drawn-in gaseous refrigerant, and ejects high-pressure gaseous refrigerant from the refrigeration cycle. In this embodiment, the compressor 100 is a single-stage turbo compressor.

[0034] However, compressor 100 is not limited to a single-stage compression turbo compressor, but can also be a multi-stage compression turbo compressor. Furthermore, the type of compressor used in the refrigeration cycle unit is not limited to a turbo compressor, but can be other types of compressors. For example, the compressor in the refrigeration cycle unit may not be a centrifugal compressor such as a turbo compressor, but a positive displacement compressor such as a screw compressor.

[0035] The compressor 100 of this embodiment is an oil-free compressor that does not use refrigeration oil (lubricating oil) to lubricate the sliding parts.

[0036] Reference Figure 2 The structure of compressor 100 will be described. Figure 2 This is a schematic sectional view of compressor 100. Compressor 100 mainly includes housing 110, compression mechanism 120, shaft 130, motor 140, magnetic bearing 150, and contact bearing (auxiliary bearing) 160.

[0037] These structures of the compressor 100 are described in summary.

[0038] The housing 110 houses various components of the compressor 100, including the compression mechanism 120, shaft 130, motor 140, magnetic bearing 150, and contact bearing 160.

[0039] The compression mechanism 120 mainly includes an impeller 122, an inlet guide vane 124, and a diffuser section 126 disposed on the outer casing 110. After accelerating the refrigerant gas through the rotation of the impeller 122, the compression mechanism 120 uses the diffuser section 126 to convert the kinetic energy of the refrigerant gas into pressure and compress the refrigerant gas.

[0040] The impeller 122 of the compression mechanism 120 is mounted on the shaft 130. The shaft 130 is connected to the rotating component 144 of the motor 140 (described later). When the rotating component 144 of the motor 140 rotates, the shaft 130 rotates, and the impeller 122 mounted on the shaft 130 rotates.

[0041] The magnetic bearing 150 magnetically levitates the shaft 130, supporting the shaft 130 so that it can rotate. When power is off or when the magnetic bearing 150 is not energized, in other words, when the shaft 130 is not magnetically levitated, the contact bearing 160 supports the shaft 130.

[0042] The housing 110, compression mechanism 120, shaft 130, motor 140, magnetic bearing 150 and contact bearing 160 are described in detail.

[0043] (2-1-1) Outer shell

[0044] The housing 110 has a cylindrical shape that is closed at both ends. The compressor 100 is arranged with the central axis O of the cylindrical housing 110 extending substantially horizontally. The internal space of the housing 110 is divided by the wall 112 into an impeller chamber S1 that houses the impeller 122 of the compression mechanism 120 and a motor chamber S2 that houses the motor 140. Figure 2 In this structure, an impeller chamber S1 is arranged on the right side of the wall portion 112, and a motor chamber S2 is arranged on the left side of the wall portion 112. Furthermore, the impeller chamber S1 and the motor chamber S2 are not separated by the wall portion 112 in an airtight manner, but are connected to each other.

[0045] The outer casing 110 is provided with an intake pipe 114 and an exhaust pipe 116.

[0046] One end of the suction tube 114 is connected to one end formed axially along the central axis O of the housing 110. Figure 2 The suction pipe 114 is connected to the right end of the impeller chamber S1 via the suction port 115. When viewed along the central axis O, the suction port 115 opens at the center of the impeller chamber S1. The other end of the suction pipe 114 (the end opposite to the side of the suction port 115 connected to the housing 110) is connected to the evaporator 40 via piping. When the compressor 100 is running, low-pressure gaseous refrigerant in the refrigeration cycle is drawn into the impeller chamber S1 through the suction pipe 114. As described above, the impeller chamber S1 is connected to the motor chamber S2; therefore, a portion of the refrigerant flowing into the impeller chamber S1 through the suction pipe 114 also flows into the motor chamber S2.

[0047] One end of the ejector pipe 116 is connected to the side of the housing 110. The ejector pipe 116 opens into the first space 118. The first space 118 is the space into which the refrigerant, accelerated by the impeller 122, flows through the diffuser section 126. The other end of the ejector pipe 116 (the end opposite to the side connected to the housing 110) is connected to the condenser 20 via piping. When the compressor 100 operates, the high-pressure gaseous refrigerant, compressed by the compression mechanism 120, is sent to the condenser 20 through the first space 118 and the ejector pipe 116.

[0048] (2-1-2) Compression mechanism

[0049] As described above, the compression mechanism 120 mainly includes an impeller 122, an inlet guide vane 124, and a diffuser section 126.

[0050] Impeller 122 has multiple blades and an approximately conical shape. Impeller 122 is disposed in impeller chamber S1. Impeller 122 is mounted on shaft 130. When shaft 130 rotates and impeller 122 rotates, gaseous refrigerant is introduced into impeller 122 and accelerated within impeller 122.

[0051] The inlet guide vane 124 is a mechanism installed at the suction port 115 of the compressor 100, which is connected to the suction pipe 114, and regulates the flow rate of refrigerant flowing towards the impeller 122. The inlet guide vane 124 is positioned upstream of the impeller 122 in the refrigerant suction direction of the compressor 100. The inlet guide vane 124 is mounted on the housing 110.

[0052] The inlet guide vane 124 mainly includes multiple blade bodies 124a, a support portion 125a, a mounting portion 125b, and a drive portion 124b for driving the blade bodies 124a. While not limited, the drive portion 124b can be a stepper motor. The blade body 124a is an airfoil-shaped member formed on a thin plate. The support portion 125a supports the blade body 124a. The support portion 125a is a member connected to the blade body 124a and forms a shaft for rotating the blade body 124a. The mounting portion 125b supports the support portion 125a so that it can rotate. The mounting portion 125b is directly or indirectly fixed to the housing 110. The drive portion 124b rotates the support portion 125a relative to the mounting portion 125b via a power transmission mechanism (not shown), thereby rotating the blade body 124a and changing the flow path area of ​​the refrigerant flow path from the suction port 115 towards the impeller 122 when viewed along the central axis O. As a result, the amount of refrigerant flowing into impeller 122 changes.

[0053] The diffuser section 126 is a refrigerant flow path that increases the refrigerant pressure by changing the refrigerant velocity. The diffuser section 126 is disposed between the impeller chamber S1 and the first space 118.

[0054] (2-1-3) axis

[0055] Shaft 130 is a drive shaft that transmits the driving force of motor 140 to impeller 122. Shaft 130 extends through impeller chamber S1 and motor chamber S2. In other words, shaft 130 extends across wall portion 112 between impeller chamber S1 and motor chamber S2. Shaft 130 is connected to the rotating component 144 of motor 140 at its central portion along its axial direction (the same as the axial direction of the central axis O of housing 110). Impeller 122 is mounted at one end of shaft 130. Disc portion 132 is provided at the other end of shaft 130.

[0056] In this compressor 100, the shaft 130 is supported by a magnetic bearing 150, therefore, the shaft 130 and the disk portion 132 are made of magnetic material.

[0057] (2-1-4) Motor

[0058] Motor 140 rotates shaft 130. Motor 140 mainly has a fixed member 142 and a rotating member 144. Fixed member 142 is cylindrical. The outer surface of fixed member 142 is fixed to the inner surface of housing 110. Rotating member 144 is cylindrical. Rotating member 144 has a small gap inside fixed member 142 and is configured to rotate. A shaft hole is formed in the center of rotating member 144 for shaft 130 to be inserted and fixed.

[0059] (2-1-5) Magnetic bearings

[0060] The magnetic bearing 150 magnetically levitates the shaft 130, supporting the shaft 130 in a non-contact manner so that it can rotate.

[0061] The magnetic bearing 150 preferably includes a first radial magnetic bearing 152, a second radial magnetic bearing 154, and a thrust magnetic bearing 156. The first radial magnetic bearing 152 is axially disposed between the impeller 122 and the motor 140 on the shaft 130. The second radial magnetic bearing 154 is axially disposed between the motor 140 and the disc portion 132 disposed at the end of the shaft 130. The thrust magnetic bearing 156 is disposed adjacent to the disc portion 132 disposed at the end of the shaft 130.

[0062] The first radial magnetic bearing 152, the second radial magnetic bearing 154, and the thrust magnetic bearing 156 each include multiple electromagnets (not shown), and the shaft 130 is supported in a non-contact manner by the combined electromagnetic force of the multiple electromagnets.

[0063] Multiple electromagnets of the first radial magnetic bearing 152 are arranged circumferentially around the shaft 130. Multiple electromagnets of the second radial magnetic bearing 154 are also arranged circumferentially around the shaft 130. Multiple electromagnets of the thrust magnetic bearing 156 are arranged such that they clamp the disk portion 132 located at the end of the shaft 130 in the axial direction. The first radial magnetic bearing 152 and the second radial magnetic bearing 154 adjust the radial position of the shaft 130. The thrust magnetic bearing 156 adjusts the axial position of the shaft 130.

[0064] The position adjustment of shaft 130 will be described in more detail. Compressor 100 is equipped with multiple sensors for detecting the radial and axial positions of shaft 130 relative to magnetic bearings 152, 154, and 156. These sensors, for example, are eddy current displacement sensors. Controller 60, described later, controls the combined electromagnetic force acting on shaft 130 based on the detection results of these sensors, so that shaft 130 is positioned relative to magnetic bearings 152, 154, and 156 at a predetermined position. Specifically, controller 60 controls the combined electromagnetic force acting on shaft 130 by controlling the current flowing in each of the multiple electromagnets of the first radial magnetic bearing 152, the second radial magnetic bearing 154, and the thrust magnetic bearing 156, thereby controlling the position of shaft 130 relative to magnetic bearings 152, 154, and 156.

[0065] (2-1-6) Contact bearings

[0066] The contact bearing 160 is the bearing that supports the shaft 130 when the magnetic bearing 150 is not energized, in other words, when the shaft 130 is not magnetically levitated.

[0067] The contact bearing 160 includes a first radial contact bearing 162 and a second radial contact bearing 164. Both the first radial contact bearing 162 and the second radial contact bearing 164 are rolling bearings. The rolling bearings can be ball bearings with "balls" as rolling elements or roller bearings with "rollers" as rolling elements. Although not limited, the inner rings, outer rings, and rolling elements of the first radial contact bearing 162 and the second radial contact bearing 164 are, for example, made of high-carbon chromium bearing steel.

[0068] The first radial contact bearing 162 is disposed adjacent to the first radial magnetic bearing 152. The first radial contact bearing 162 is disposed axially between the impeller 122 and the first radial magnetic bearing 152 on the shaft 130. However, it is not limited to this, the first radial contact bearing 162 may also be disposed axially between the first radial magnetic bearing 152 and the motor 140 on the shaft 130.

[0069] The second radial contact bearing 164 is disposed adjacent to the second radial magnetic bearing 154. The second radial contact bearing 164 is disposed axially between the second radial magnetic bearing 154 and the disk portion 132 disposed at the end of the shaft 130. However, it is not limited to this, the second radial contact bearing 164 may also be disposed axially between the motor 140 and the second radial magnetic bearing 154.

[0070] (2-2) Condenser

[0071] In this embodiment, the condenser 20 is a water-cooled condenser. However, the condenser 20 of the cooling device 10 is not limited to a water-cooled condenser and may also be an air-cooled condenser.

[0072] The type of heat exchanger in condenser 20 is not limited; for example, it can be a shell-and-tube condenser. For example, cooling water cooled by a cooling tower (not shown) is supplied to condenser 20, where heat exchange occurs between the cooling water and the refrigerant.

[0073] (2-3) Expansion valve

[0074] In this embodiment, the expansion valve 30 is an electronic expansion valve. However, the expansion valve 30 may also be an automatic temperature expansion valve with a temperature sensing cylinder. Furthermore, the cooling device 10 may also have a capillary tube instead of the expansion valve 30 as the expansion mechanism.

[0075] like Figure 1 Thus, the expansion valve 30 mainly includes a valve core 32 and a drive unit 34 that drives the valve core 32. While not limited, the drive unit 34 can be a stepper motor. The controller 60, described later, controls the drive unit 34 to drive the valve core 32 and control the opening degree of the expansion valve 30 based on the measurement results of one or more sensors (not shown) that measure the temperature or pressure of the refrigerant at a predetermined location in the refrigerant circuit 50. When the drive unit 34 drives the valve core 32, the valve core 32 moves either by narrowing the refrigerant flow path within the expansion valve 30 while sliding on the side wall 32a surrounding the valve core 32, or by widening the refrigerant flow path within the expansion valve 30 while sliding on the side wall 32a surrounding the valve core 32. For example, in... Figure 1 In this process, the valve core 32 slides on the side wall 32a surrounding the valve core 32 while moving up and down. Although the control method is not limited, the controller 60 controls the drive unit 34 to drive the valve core 32 in such a way as to make the superheat calculated from the refrigerant evaporation temperature measured by the sensor and the refrigerant temperature at the outlet of the evaporator 40 reach a target value, thereby controlling the opening degree of the expansion valve 30.

[0076] (2-4) Evaporator

[0077] In this embodiment, the evaporator 40 is a liquid cooling evaporator. However, the evaporator 40 of the cooling device 10 is not limited to a liquid cooling evaporator, and may also be an air cooling evaporator.

[0078] The type of heat exchanger in evaporator 40 is not limited; for example, it can be a shell-and-tube condenser. Liquid (heat medium) is supplied to evaporator 40, where heat exchange occurs between the liquid and the refrigerant, thereby cooling the liquid. The cooled liquid in evaporator 40 is then supplied to a utilization-side device (not shown) that utilizes the cooled liquid for purposes such as air conditioning and cooling of equipment.

[0079] (2-5) Controller

[0080] The controller 60 is a device that controls the operation of various parts of the cooling unit 10. The controller 60 is electrically connected to the compressor 100 and the expansion valve 30, for example, in a manner capable of controlling the operation of the compressor 100 and the expansion valve 30. Furthermore, the controller 60 is connected to sensors (not shown) for detecting the radial and axial positions of the shaft 130 relative to the magnetic bearings 152, 154, and 156, and sensors (not shown) for measuring the temperature or pressure of the refrigerant at specified locations in the refrigerant circuit 50, in a manner capable of receiving signals from the sensors.

[0081] The controller 60 may include, for example, a microprocessor or CPU, an input / output interface, RAM and ROM, and a storage device storing a control program for controlling the operation of the cooling device 10. Furthermore, the controller 60 may also include an input device for accepting input from the user, a display device for providing various information to the user, etc.

[0082] As described above, the controller 60 controls the combined electromagnetic force acting on the shaft 130 based on the detection results of the sensors used to detect the radial and axial positions of the shaft 130 relative to the magnetic bearings 152, 154, and 156, so that the shaft 130 is positioned in a specified position relative to the magnetic bearings 152, 154, and 156.

[0083] Furthermore, the controller 60 controls the rotational speed of the motor 140 of the compressor 100 based on the measurement results of a sensor (not shown) that measures the temperature or pressure of the refrigerant at a predetermined location in the refrigerant circuit 50, thereby controlling the capacity of the compressor 100. Additionally, the controller 60 controls the drive unit 124b of the inlet guide vane 124 based on the measurement results of the sensor (not shown) that measures the temperature or pressure of the refrigerant at a predetermined location in the refrigerant circuit 50, thereby controlling the amount of refrigerant flowing into the impeller 122. Furthermore, the controller 60 controls the drive unit 34 of the expansion valve 30 based on the measurement results of a sensor (not shown) that measures the temperature or pressure of the refrigerant at a predetermined location in the refrigerant circuit 50, adjusting the opening degree of the expansion valve 30. Various methods can be used by the controller 60 to control the motor 140, the inlet guide vane 124, and the expansion valve 30.

[0084] (3) Lubricating grease

[0085] In the cooling device 10, at least one of the devices provided in the refrigerant circuit 50 uses a lubricating grease (referred to as grease G). More specifically, grease G is used at locations in the device provided in the refrigerant circuit 50 where lubrication is required and where refrigerant may flow. In other words, grease G is used at locations in the device provided in the refrigerant circuit 50 where one component slides relative to other components and where refrigerant may flow.

[0086] As a specific example, grease G is used in at least one of the following: contact bearing 160 (first radial contact bearing 162 and second radial contact bearing 164); drive portion 124b of inlet guide vane 124; and drive portion 34 of expansion valve 30. Specifically, in the cooling device 10 of this embodiment, grease G is used as a lubricant in the contact bearing 160, drive portion 124b of inlet guide vane 124, and drive portion 34 of expansion valve 30. Furthermore, specifically, the portion of inlet guide vane 124 using grease G is the rolling bearing 124ba within the stepper motor that serves as drive portion 124b of inlet guide vane 124. Specifically, the portion of expansion valve 30 using grease G is the rolling bearing 34a within the stepper motor that serves as drive portion 34 of expansion valve 30. Additionally, the rolling bearings 34a and 124ba can be ball bearings with "balls" as rolling elements or roller bearings with "rollers" as rolling elements. Furthermore, although not limited, the inner ring, outer ring, and rolling elements of rolling bearings 34a and 124ba are, for example, made of high-carbon chromium bearing steel.

[0087] Alternatively, grease G may be used only in a portion of the contact bearing 160, the drive section 124b of the inlet guide vane 124, and the drive section 34 of the drive valve 30. Furthermore, grease G may also be used in other locations of the compressor 100 and / or the expansion valve 30 where lubrication is required and refrigerant may flow. Additionally, grease G may be used in other equipment besides the compressor 100 and the expansion valve 30 where lubrication is required and refrigerant may flow.

[0088] Grease G is a grease containing fluorine, which has high chemical stability. In particular, in order to suppress the effect of using a refrigerant containing chlorine atoms and olefin bonds in the refrigerant circuit 50 on the grease, it is preferable to use a grease containing more than 10% by weight of fluorine as grease G.

[0089] Grease G primarily contains base oils that form the base material and thickeners dispersed within the base oils. Base oils used in Grease G include, for example, mineral oils, synthetic hydrocarbon oils, ether oils, ester oils, polyethylene glycol oils, silicone oils, fluorosilicone oils, and fluorinated oils. Thickeners used in Grease G include, for example, calcium soaps, lithium soaps, sodium soaps, complex calcium soaps, complex aluminum soaps, complex lithium soaps, complex barium soaps, bentonite, urea compounds, and fluoropolymers (PTFE, etc.).

[0090] When grease G uses a base oil that is fluorine-free, a fluorinated thickener is used. Conversely, when grease G does not use a fluorinated thickener, a fluorinated base oil is used.

[0091] In particular, preferably, in grease G, a fluorinated oil (in the example of a base oil, a fluorosilicone oil or a fluorinated oil) is used as the base oil, and a fluoropolymer is used as the thickener. Furthermore, as mentioned above, grease G preferably contains 10% by weight or more of fluorine.

[0092] (4) Features

[0093] (4-1)

[0094] The grease G in this embodiment is a grease used in a device provided in a refrigerant circuit 50, which supplies a refrigerant containing chlorine atoms and olefin bonds within its molecules. The grease G contains fluorine.

[0095] By using fluorinated grease G, which has high chemical stability, the decline in the function of grease G as a lubricant can be suppressed even when using refrigerants with high oil solubility and containing chlorine atoms and olefin bonds in the molecule.

[0096] (4-2)

[0097] Refrigerants containing chlorine atoms and olefin bonds within their molecules include, for example, R1233zd(E) (trans-1-chloro-3,3,3-trifluoropropylene). Refrigerants can be single-component refrigerants or mixtures of two or more refrigerants.

[0098] R1233zd(E) is a safe refrigerant with a low global warming coefficient, zero ozone depletion potential, low environmental impact, non-flammability, and low toxicity. By using grease G as a lubricant, it is possible to use such an environmentally friendly and safe refrigerant, and to prevent poor sliding of sliding parts in the equipment in the refrigerant circuit 50.

[0099] (4-3)

[0100] In this embodiment, the lubricating grease G is preferably made of fluorinated oil as the base oil.

[0101] By using grease G with a base oil containing fluorine, which has high chemical stability, the function of grease G as a lubricant can be suppressed even when using refrigerants that contain chlorine atoms and olefin bonds in their molecules and have high oil solubility.

[0102] Furthermore, the grease G in this embodiment preferably uses a fluoropolymer as a thickener.

[0103] By using grease G containing a chemically stable fluoropolymer as a thickener, the decline in the function of grease G as a lubricant can be suppressed even when using refrigerants that contain chlorine atoms and olefin bonds in their molecules and have high oil solubility.

[0104] Furthermore, it is particularly preferred that, in the grease G, a fluorinated oil is used as the base oil and a fluoropolymer is used as the thickener.

[0105] (4-4)

[0106] In this embodiment, the grease G is preferably used as a lubricant in at least one of the following ways:

[0107] 1. Examples of rolling bearings that provide shaft support for a shaft 130 connected to a motor 140 of a compressor 100 provided in a refrigerant circuit 50, including a first radial contact bearing 162 and a second radial contact bearing 164.

[0108] 2. A drive unit 124b is provided for the inlet guide vane 124 of the suction port 115 of the compressor 100 provided in the refrigerant circuit 50;

[0109] 3. The drive part 34 of the valve core 32 of the expansion valve 30 installed in the refrigerant circuit 50.

[0110] In this embodiment, grease G is used in all three of the above-mentioned locations.

[0111] Specifically, the portion of the inlet guide vane 124 that uses grease G is the rolling bearing 124ba within the drive section 124b of the inlet guide vane 124. Similarly, the portion of the expansion valve 30 that uses grease G is the rolling bearing 34a within the drive section 34 of the expansion valve 30.

[0112] By using a chemically stable grease G, damage to radial contact bearings 162 and 164, inlet guide vanes 124, expansion valves 30, etc., can be suppressed even when using refrigerants containing chlorine atoms and olefin bonds within their molecules.

[0113] (4-5)

[0114] An example of the refrigeration cycle apparatus of this embodiment, namely the cooling device 10, includes a refrigerant circuit 50, which supplies a refrigerant containing chlorine atoms and olefin bonds within its molecules. The refrigerant circuit 50 includes at least a compressor 100 and an expansion valve 30. The compressor 100 includes an inlet guide vane 124, a motor 140, a shaft 130, an impeller 122, a first radial contact bearing 162 (an example of a rolling bearing), and a second radial contact bearing 164. The inlet guide vane 124 is disposed at the suction port 115 of the compressor 100. The shaft 130 is connected to the motor 140. The impeller 122 is disposed on the shaft 130. The first radial contact bearing 162 and the second radial contact bearing 164 provide shaft support for the shaft 130. The expansion valve 30 includes a valve core 32 and a drive portion 34 for the valve core 32. In at least one of the first radial contact bearing 162 and the second radial contact bearing 164 of the compressor 100, the drive portion 124b of the inlet guide vane 124 of the compressor 100, and the drive portion 34 of the expansion valve 30, a fluorinated grease G is used as a lubricant.

[0115] In the cooling device 10 of this embodiment, even when a refrigerant containing chlorine atoms and olefin bonds in its molecule is used, damage to radial contact bearings 162 and 164, inlet guide vanes 124, expansion valves 30, etc., which use grease, can be suppressed.

[0116] (5) Variations

[0117] Hereinafter, variations of the above embodiments will be described. Furthermore, the following variations can be appropriately combined without contradicting each other.

[0118] (5-1) Variation A

[0119] In the above embodiment, the compressor 100 of the cooling device 10 is a turbo compressor. However, as mentioned above, the compressor 100 of the cooling device 10 can also be a screw compressor. In the case where the compressor 100 is a screw compressor, for example, grease G can also be used for the rolling bearing that supports the shaft on which the rotor is mounted.

[0120] (5-2) Variation B

[0121] In the above embodiment, the compressor 100 has a magnetic bearing 150 and a contact bearing 160 as bearings for supporting the shaft 130, but is not limited thereto.

[0122] For example, compressor 100 may not have magnetic bearing 150, but only rolling bearing as the bearing for shaft 130. In other words, in compressor 100, shaft 130 can always be supported by rolling bearing. In this case, grease G is preferably used as the lubricant for the rolling bearing of compressor 100.

[0123] (5-3) Variation C

[0124] In the above embodiment, compressor 100 is a type of compressor that does not use refrigeration oil; however, it is not limited to this. Compressor 100 may also be a compressor that uses refrigeration oil. Furthermore, in this case, grease G may not be used for the first radial contact bearing 162 and the second radial contact bearing 164.

[0125] <Postscript>

[0126] The embodiments and variations of this disclosure have been described above. However, it should be understood that various changes in form and detail can be made without departing from the spirit and scope of this disclosure as set forth in the claims.

[0127] Industrial availability

[0128] The grease disclosed herein is useful for use in refrigeration cycle devices, in refrigerant circuits for refrigerants containing chlorine atoms and olefin bonds within their molecules.

[0129] Symbol Explanation

[0130] 10. Cooling Unit (Refrigeration Circulation Unit)

[0131] 30 Expansion Valve

[0132] 32 valve core

[0133] 34 Drive Unit

[0134] 50 refrigerant circuit

[0135] 100 compressor (turbo compressor)

[0136] 115 suction port

[0137] 122 impeller

[0138] 124 imported guide vanes

[0139] 124b drive unit

[0140] 130 axis

[0141] 140 motor

[0142] 162 First radial contact bearing (rolling bearing)

[0143] 164 Second Radial Contact Bearing (Rolling Bearing)

[0144] G grease

[0145] Existing technical documents

[0146] Patent documents

[0147] Patent Document 1: Japanese Patent Application Publication No. 2011-520089.

Claims

1. A refrigeration cycle device (10), the refrigeration cycle device comprising a refrigerant circuit (50), wherein a refrigerant containing chlorine atoms and olefin bonds within its molecules flows in the refrigerant circuit (50), characterized in that, The refrigerant circuit is equipped with at least a turbo compressor (100) and an expansion valve (30). The turbo compressor includes an inlet guide vane (124) disposed at the suction port (115) of the turbo compressor, a motor (140), a shaft (130) connected to the motor, an impeller (122) disposed on the shaft, and rolling bearings (162, 164) that support the shaft. The expansion valve includes a valve core (32) and a drive part (34) of the valve core. In at least one of the rolling bearing of the turbo compressor, the drive part (124b) of the inlet guide vane of the turbo compressor, and the drive part (34) of the expansion valve, a grease (G) containing more than 10% by weight of fluorine is used as a lubricant.

2. The refrigeration cycle apparatus as described in claim 1, characterized in that, The refrigerant includes R1233zd(E).

3. The refrigeration cycle apparatus as described in claim 1 or 2, characterized in that, The grease uses a fluorinated oil as its base oil.

4. The refrigeration cycle apparatus as described in claim 1 or 2, characterized in that, In the grease, fluoropolymer is used as a thickener.

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