JP2018169052A - Air conditioner - Google Patents

Abstract

To suppress generation of a disproportionation reaction in a refrigerant.SOLUTION: An air conditioner 1 has a refrigerant circuit 1a in which a compressor 10, an outdoor heat exchanger 23, a throttle device 24 and an indoor heat exchanger 51 are connected sequentially and in which a refrigerant circulates. The air conditioner 1 includes: an outdoor unit 2 including the compressor 10, the outdoor heat exchanger 23 and the throttle device 24; an indoor unit 5 including the indoor heat exchanger 51; and an outdoor unit control part 200. It also includes: a liquid injection connection pipe 46 for supplying a liquid refrigerant inside the refrigerant circuit 1a to a slide part of the compressor 10; and a solenoid valve 26 provided at the liquid injection connection pipe 46. The outdoor unit control part 200 controls opening/closing of the solenoid valve 26 so that a slide part temperature of the compressor 10 becomes a first threshold temperature in which a disproportionation reaction does not occur in the refrigerant.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an air conditioner.

  In an air conditioner including a compressor that compresses a refrigerant, an R410A refrigerant that is a hydrofluorocarbon (HFC) is widely used as the refrigerant. However, the R410A refrigerant has a large global warming potential (GWP). Thus, as a refrigerant having a relatively small GWP, a related technology using a hydrofluoroolefin (HFO) 1123 refrigerant and a mixed refrigerant containing an HFO 1123 refrigerant is known.

International Publication No. 2012/157774

However, HFO1123 refrigerant has the following chemical reaction formula under the given conditions:
CF2 = CHF → 1 / 2CF4 + 3 / 2C + HF + 20 kJ / mol
It has the property of causing a disproportionation reaction expressed by: The disproportionation reaction occurs, for example, when the temperature or pressure rises in a high-density state of the HFO 1123 refrigerant, or when some strong energy is applied to the HFO 1123 refrigerant. When a disproportionation reaction occurs in the HFO1123 refrigerant, a large amount of heat is generated. Therefore, when a disproportionation reaction occurs, the operation reliability of the air conditioner including the compressor is lowered or a sudden pressure increase is caused. There is a risk of damaging the piping in the air conditioner.

  In the operation of recovering the refrigerant in the refrigerant circuit in the outdoor unit (pump down operation), which is performed at the time of repair or relocation of the air conditioner, the refrigerant on the low pressure side gradually disappears. The temperature of the moving part may rise. In particular, in the rotary compressor, the temperature of the sliding portion between the tip of the vane and the outer peripheral surface of the piston becomes relatively high in the entire rotary compressor, and the temperature may locally rise to about 250 ° C. For this reason, in the rotary compressor using the HFO1123 refrigerant, there is a possibility that a disproportionation reaction may occur in the HFO1123 refrigerant due to the temperature rise of the sliding portion between the tip of the vane and the outer peripheral surface of the piston. For this reason, in the air conditioning apparatus using the HFO 1123 refrigerant, there is a possibility that a disproportionation reaction may occur in the HFO refrigerant due to the temperature rise of the sliding portion of the compressor during the pump down operation.

  The disclosed technology has been made in view of the above, and an object thereof is to provide an air conditioner that can suppress the occurrence of a disproportionation reaction in a refrigerant.

  One aspect of the air conditioner disclosed in the present application includes a refrigerant circuit in which a compressor, an outdoor heat exchanger, a throttling device, and an indoor heat exchanger are sequentially connected, and a refrigerant circulates therein. An air conditioner having an outdoor unit provided with an outdoor heat exchanger, an indoor unit provided with the indoor heat exchanger, and a control means, wherein liquid refrigerant in the refrigerant circuit is transferred to a sliding portion of the compressor. A liquid injection pipe to be supplied; an electromagnetic valve provided in the liquid injection pipe; and a sliding part temperature detecting means for detecting a sliding part temperature of the compressor, wherein the control means is a sliding part of the compressor. The solenoid valve is controlled so that the temperature of the part becomes a temperature at which disproportionation reaction does not occur in the refrigerant.

  According to one aspect of the air conditioner disclosed in the present application, it is possible to suppress the occurrence of a disproportionation reaction in the refrigerant.

FIG. 1 is a refrigerant circuit diagram illustrating the air conditioner of the first embodiment. FIG. 2 is a longitudinal sectional view showing the rotary compressor of the first embodiment. FIG. 3 is a cross-sectional view illustrating the rotary compressor according to the first embodiment. FIG. 4 is a flowchart illustrating a control mode of the air-conditioning apparatus according to the first embodiment. FIG. 5 is a graph showing the pressure and temperature at which HFO 1123 causes a disproportionation reaction.

  Embodiments of an air conditioner disclosed in the present application will be described below in detail with reference to the drawings. In addition, the air conditioning apparatus which this application discloses is not limited by the following examples.

[Configuration of air conditioner]
FIG. 1 is a refrigerant circuit diagram illustrating the air conditioner of the first embodiment. As shown in FIG. 1, the air conditioning apparatus 1 includes an outdoor unit 2 and an indoor unit 5. The outdoor unit 2 and the indoor unit 5 are connected by a liquid pipe 6a and a gas pipe 6b to form a refrigerant circuit 1a in which the refrigerant circulates. The outdoor unit 2 includes a rotary compressor 10, a four-way valve 22, an outdoor heat exchanger 23, a throttling device (decompressor) 24, a liquid injection connecting pipe 46, a solenoid valve 26, a capillary tube 27, a liquid side closing valve 61, and a gas side. A shut-off valve 62 and an outdoor unit controller 200 are provided.

  The rotary compressor 10 includes a discharge port 107 as a discharge unit and suction ports (104, 105) as suction units. The rotary compressor 10 is controlled by the outdoor unit control unit 200 to compress the refrigerant supplied from the suction ports (104, 105) via the suction pipe 42 and the four-way valve 22, and from the discharge port 107, The compressed refrigerant is supplied to the four-way valve 22 through the discharge pipe 41. As the refrigerant, HFO1123 refrigerant or a mixed refrigerant containing HFO1123 refrigerant is used.

  The four-way valve 22 is connected to the discharge pipe 41 and the suction pipe 42, and is connected to the outdoor heat exchanger 23 via the refrigerant pipe 43, and to the indoor unit 5 via the refrigerant pipe 44 and the gas-side closing valve 6b. ing. The indoor unit 5 and the outdoor heat exchanger 23 are connected via a liquid side shut-off valve 6a and a refrigerant pipe 45. The four-way valve 22 is controlled by the outdoor unit control unit 200 to switch the air conditioner 1 to either the heating mode or the cooling mode. When switched to the cooling mode, the four-way valve 22 supplies the refrigerant discharged from the rotary compressor 10 via the discharge pipe 41 to the outdoor heat exchanger 23, and the refrigerant flowing out of the indoor unit 5 is supplied to the rotary compressor 10. Supply is made through the suction pipe 42. When switched to the heating mode, the four-way valve 22 supplies the refrigerant discharged from the rotary compressor 10 via the discharge pipe 41 to the indoor unit 5 and supplies the refrigerant flowing out of the outdoor heat exchanger 23 to the rotary compressor 10. Supply is made through the suction pipe 42. The four-way valve 22 during the pump-down operation for collecting the refrigerant in the refrigerant circuit when the air conditioner 1 is repaired or moved is returned to the outdoor unit via the discharge pipe 41 as in the case of switching to the cooling mode. The refrigerant discharged from the rotary compressor 10 is supplied to the outdoor heat exchanger 23, and the refrigerant flowing out from the indoor unit 5 is supplied to the rotary compressor 10 via the suction pipe 42. Since the liquid side shut-off valve 61 is closed during the pump down operation, the refrigerant in the liquid pipe 6a, the indoor heat exchanger 51, the gas pipe 62, the refrigerant pipe 44, and the suction pipe 42 is recovered downstream from the compressor 10. Is done.

  The outdoor heat exchanger 23 is connected to the expansion device 24 via the refrigerant pipe 45. An outdoor fan 27 is disposed in the vicinity of the outdoor heat exchanger 23. The outdoor fan 27 is rotated by a fan motor (not shown), thereby taking outside air into the outdoor unit 2 and releasing outside air heat-exchanged with the refrigerant by the outdoor heat exchanger 23 to the outside of the outdoor unit 2. . In the cooling mode, the outdoor heat exchanger 23 exchanges heat between the refrigerant supplied from the four-way valve 22 and the outside air taken into the outdoor unit 2, and supplies the heat-exchanged refrigerant to the expansion device 24. To do. In the heating mode, the outdoor heat exchanger 23 exchanges heat between the refrigerant supplied from the expansion device 24 and the outside air taken into the outdoor unit 2 and supplies the heat-exchanged refrigerant to the four-way valve 22. To do.

  The expansion device 24 is connected to the indoor unit 5 via the refrigerant pipe 45 and the liquid side shut-off valve 6a. The expansion device 24 decompresses the refrigerant supplied from the outdoor heat exchanger 23 by adiabatic expansion in the cooling mode, and supplies the low-temperature and low-pressure two-phase refrigerant to the indoor unit 5. In the heating mode, the expansion device 24 decompresses the refrigerant supplied from the indoor unit 5 by adiabatic expansion, and supplies the low-temperature and low-pressure two-phase refrigerant to the outdoor heat exchanger 23. Further, the expansion device 24 is controlled by the outdoor unit control unit 200 so that the opening degree is adjusted, and in the heating mode, the flow rate of the refrigerant supplied from the indoor unit 5 to the outdoor heat exchanger 23 is adjusted. In the cooling mode, the flow rate of the refrigerant supplied from the outdoor heat exchanger 23 to the indoor unit 5 is adjusted.

  The liquid injection connecting pipe 46 connects a path between the outdoor heat exchanger 23 and the expansion device 24 in the refrigerant pipe 45 and an injection pipe 142 (described later) of the compressor 10. The electromagnetic valve 26 is provided in the middle of the liquid injection connecting pipe 46. The electromagnetic valve 26 is controlled by the outdoor unit control unit 200, so that the space between the outdoor heat exchanger 23 and the expansion device 24 in the refrigerant pipe 45 is transferred to the injection pipe 142 of the compressor 10 via the liquid injection connection pipe 46. Supply the refrigerant or stop supplying the refrigerant. The capillary tube 27 is provided in the middle of the liquid injection connecting pipe 46. The capillary tube 27 adjusts the amount of refrigerant supplied to the injection pipe 142 of the compressor 10 to a predetermined amount.

  The indoor unit 5 includes an indoor heat exchanger 51, an indoor fan 55, and an indoor unit control unit 500. The indoor fan 55 is disposed in the vicinity of the indoor heat exchanger 51, is rotated by a fan motor (not shown), takes indoor air into the indoor unit 5, and is cooled by the indoor heat exchanger 51. The indoor air heat-exchanged with is released into the room. The indoor heat exchanger 51 is connected to the four-way valve 22 via the gas-side stop valve 6b and the refrigerant pipe 44, and to the expansion device 24 of the outdoor unit 2 via the refrigerant pipe 45, respectively. The indoor heat exchanger 51 functions as an evaporator when the air conditioner 1 is switched to the cooling mode, and functions as a condenser when the air conditioner 1 is switched to the heating mode. In other words, in the cooling mode, the indoor heat exchanger 51 exchanges heat between the low-temperature and low-pressure two-phase refrigerant supplied from the expansion device 24 and the indoor air taken into the indoor unit 5. The heat-exchanged room air is discharged into the room, and the heat-exchanged refrigerant is supplied to the four-way valve 22. In the heating mode, the indoor heat exchanger 51 exchanges heat between the refrigerant supplied from the four-way valve 22 and the indoor air taken into the indoor unit 5, and the heat-exchanged indoor air enters the room. The refrigerant that has been discharged and the heat exchanged is supplied to the expansion device 24.

(Configuration of rotary compressor)
FIG. 2 is a longitudinal sectional view showing the rotary compressor of the embodiment. FIG. 3 is a cross-sectional view of the compression portion of the rotary compressor of the embodiment as viewed from above.

  As shown in FIG. 1, the rotary compressor 10 includes a compression unit 120 disposed at a lower portion in a sealed vertical cylindrical compressor housing 100 and a rotation portion disposed at an upper portion in the compressor housing 100. A motor 110 that drives the compression unit 120 via a shaft 150 and a vertically installed cylindrical accumulator 25 that is fixed and sealed to the outer peripheral surface of the compressor housing 100 are provided.

  The accumulator 25 is connected to the upper cylinder chamber 130T (see FIG. 3) of the upper cylinder 121T via the upper suction pipe 105 and the accumulator upper curved pipe 31T as the suction section, and the lower suction pipe 104 and the lower accumulator curve as the suction section. A lower cylinder chamber 130S (see FIG. 3) is connected to the lower cylinder 121S through a pipe 31S. In the present embodiment, the positions of the upper suction pipe 105 and the lower suction pipe 104 overlap in the circumferential direction of the compressor housing 10 and are located at the same position.

  The motor 110 includes a stator 111 disposed on the outer side and a rotor 112 disposed on the inner side. The stator 111 is fixed to the inner peripheral surface of the compressor housing 100 in a shrink-fitted state. The rotor 112 is fixed to the rotating shaft 150 in a shrink-fitted state.

  In the rotating shaft 150, the lower auxiliary shaft portion 151 is rotatably supported by the lower end plate 160S, and the upper main shaft portion 153 is rotatably supported by the upper end plate 160T. An upper piston 125T and a lower piston 125S are supported on the rotation shaft 150. As a result, the rotary shaft 150 is rotatably supported with respect to the entire compression portion 120, and the upper piston 125T is caused to revolve along the inner peripheral surface of the upper cylinder 121T by rotation, and the lower piston 125S is moved to the lower cylinder 121S. Revolve along the inner circumference of the.

  Inside the compressor housing 100, the lubricity of sliding parts such as the upper piston 125T and the lower piston 125S sliding in the compression part 120 is ensured, and the upper compression chamber 133T (see FIG. 3) and the lower compression chamber 133S are secured. In order to seal (refer FIG. 3), the lubricating oil 18 is enclosed by the quantity which substantially immerses the compression part 120. FIG.

  As shown in FIG. 3, an upper cylinder inner wall 123 </ b> T is formed on the upper cylinder 121 </ b> T along a concentric circle with the rotation shaft 150 of the motor 11. An upper piston 125T having an outer diameter smaller than the inner diameter of the upper cylinder 121T is disposed in the upper cylinder inner wall 123T, and the refrigerant is sucked, compressed, and discharged between the upper cylinder inner wall 123T and the upper piston 125T. An upper compression chamber 133T is formed. A lower cylinder inner wall 123S is formed on the lower cylinder 121S along a concentric circle with the rotation shaft 150 of the motor 11. A lower piston 125S having an outer diameter smaller than the inner diameter of the lower cylinder 121S is disposed in the lower cylinder inner wall 123S. The refrigerant is sucked, compressed, and discharged between the lower cylinder inner wall 123S and the lower piston 125S. A lower compression chamber 133S is formed.

  As shown in FIGS. 2 and 3, the upper cylinder 121 </ b> T has an upper protrusion 122 </ b> T that protrudes from the circular outer peripheral portion in the radial direction of the rotation shaft 150. The upper protruding portion 122T is provided with an upper vane groove 128T that extends radially outward from the upper cylinder chamber 130T. An upper vane 127T is slidably disposed in the upper vane groove 128T. The upper vane 127T has a sliding surface 137T that contacts the outer peripheral surface of the upper piston 125T. The lower cylinder 121 </ b> S includes a lower side protrusion 122 </ b> S that protrudes from the circular outer peripheral portion in the radial direction of the rotation shaft 150. The lower side protrusion 122S is provided with a lower vane groove 128S extending radially outward from the lower cylinder chamber 130S. A lower vane 127S is slidably disposed in the lower vane groove 128S. The lower vane 127S has a sliding surface 137S that contacts the outer peripheral surface of the lower piston 125S.

  The upper side protruding portion 122T and the lower side protruding portion 122S are formed over a predetermined protruding range along the circumferential direction of the rotating shaft 150. The upper side protruding part 122T and the lower side protruding part 122S are used as chuck holding parts for fixing to the processing jig when the upper cylinder 121T and the lower cylinder 121S are processed.

  An upper spring hole 124T is provided in the upper protruding portion 122T at a depth that does not penetrate the upper cylinder chamber 130T at a position overlapping the upper vane groove 128T from the outer surface. A spring (not shown) is disposed in the upper spring hole 124T. A lower spring hole 124S is provided in the lower side protrusion 122S at a position that overlaps with the lower vane groove 128S from the outer surface with a depth that does not penetrate the lower cylinder chamber 130S. A spring (not shown) is disposed in the lower spring hole 124S.

  Further, the refrigerant compressed in the compressor casing 100 is introduced into the lower cylinder 121S through the radially outer side of the lower vane groove 128S and the interior of the compressor casing 100, and the pressure of the refrigerant is applied to the lower vane 127S. Thus, a lower pressure introduction path 129S for applying back pressure is formed. Further, the refrigerant compressed in the compressor casing 100 is introduced into the upper cylinder 121T by communicating the radially outer side of the upper vane groove 128T with the inside of the compressor casing 100 through the opening, and the compressed refrigerant in the compressor casing 100 is introduced into the upper vane 127T. An upper pressure introduction path 129T that applies back pressure by the pressure of the refrigerant is formed.

  As shown in FIG. 3, an upper suction hole 135 </ b> T that fits into the upper suction pipe 105 is provided in the upper protrusion 122 </ b> T of the upper cylinder 121 </ b> T. A lower suction hole 135S that fits into the lower suction pipe 104 is provided in the lower side protruding portion 122S of the lower cylinder 121S.

  As shown in FIG. 2, the upper cylinder chamber 130T is closed by an upper end plate 160T and an intermediate partition plate 140 on the upper and lower sides, respectively. The lower cylinder chamber 130S is closed at the top and bottom by an intermediate partition plate 140 and a lower end plate 160S, respectively.

  As shown in FIG. 3, the upper cylinder chamber 130T includes an upper suction chamber 131T communicating with the upper suction hole 135T and an upper end of the upper vane 127T pressed by the upper spring 126T and abutting against the outer peripheral surface of the upper piston 125T. An upper compression chamber 133T communicating with an upper discharge hole 190T provided in the plate 160T is partitioned. The lower cylinder chamber 130S includes a lower suction chamber 131S communicating with the lower suction hole 135S and a lower plate provided in the lower end plate 160S when the lower vane 127S is pressed by the lower spring 126S and comes into contact with the outer peripheral surface of the lower piston 125S. And a lower compression chamber 133S communicating with the discharge hole 190S.

  The upper discharge hole 190T is provided in the vicinity of the upper vane groove 128T, and the lower discharge hole 190S is provided in the vicinity of the lower vane groove 128S. The refrigerant compressed in the upper compression chamber 133T and the lower compression chamber 133S is discharged from the upper compression chamber 133T and the lower compression chamber 133S through the upper discharge hole 190T and the lower discharge hole 190S.

  As shown in FIGS. 3 and 4, the intermediate partition plate 140 is formed with injection holes 140a along the radial direction of the intermediate partition plate 140, and injects liquid refrigerant into the upper compression chamber 133T and the lower compression chamber 133S. An injection tube 142 is fitted into the injection hole 140a. In addition, circular injection ports 141T and 141S are provided on both upper and lower surfaces of the intermediate partition plate 140 so as to communicate with the injection holes 140a and penetrate one end of the intermediate partition plate 140 in the thickness direction (direction of the rotation shaft 150). Yes. The injection ports 141T and 141S of the injection hole 140a are formed by using the sliding surface 137T of the upper vane 127T with the upper piston 125T and the sliding surface 137S of the lower vane 127S with the lower piston 125S, and the injection ports 141T and 141S of the injection hole 140a. It is provided in a position where it can be cooled by the liquid refrigerant injected from. The injection ports 141T and 141S of the injection hole 140a in the embodiment are provided in the intermediate partition plate 140 so as to open into the upper cylinder chamber 130T and the lower cylinder chamber 130S. On the plane orthogonal to the rotation shaft 150, the injection ports 141T and 141S of the injection hole 140a are located in the upper cylinder chamber 130T (upper compression chamber 133T) and on the lower side of the upper discharge groove 190T with respect to the upper vane groove 128T. It arrange | positions so that it may open in the lower cylinder chamber 130S (lower compression chamber 133S) of the lower discharge hole 190S side with respect to the vane groove | channel 128S.

  Here, the position that can be cooled by the liquid refrigerant is limited to a position where the liquid refrigerant injected into the upper compression chamber 133T and the lower compression chamber 133S is blown directly onto the sliding surfaces 137T and 137S. Instead, the sliding surface indirectly through the gas refrigerant in the space in which the liquid refrigerant is sprayed in the upper compression chamber 133T and the lower compression chamber 133S (the gas refrigerant in the space cooled by the mist of the liquid refrigerant). It includes a position where 137T and 137S are cooled. In other words, the injection port 141T of the injection hole 140a opens in the vicinity of the sliding surface 137T, and the injection port 141S opens in the vicinity of the sliding surface 137S, thereby indirectly through the space cooled by the liquid refrigerant. The sliding surfaces 137T and 137S can be cooled.

  One end of the injection pipe 142 is drawn out to the outer peripheral surface of the compressor housing 100 and is connected to an injection connecting pipe 46 through which liquid refrigerant is introduced from the refrigerant circulation path. In the rotary compressor 1, the liquid refrigerant supplied from the injection pipe 142 is injected into the upper compression chamber 133T and the lower compression chamber 133S from the injection ports 141T and 141S of the injection holes 140a of the intermediate partition plate 140, and the latter stage of the compression process. Refrigerant compression efficiency is increased by lowering the temperature of the refrigerant.

  Further, the liquid refrigerant injected into the upper compression chamber 133T and the lower compression chamber 133S from the injection hole 140a has the first action of increasing the refrigerant compression efficiency by cooling the refrigerant in the latter stage of the compression process, and the upper vane 127T. This also serves as a second action for cooling the sliding face 137T and the sliding face 137S of the lower vane 127S (an action for suppressing the disproportionation reaction of the refrigerant). The positions of the injection ports 141T and 141S of the injection hole 140a are opened in the upper compression chamber 133T and the lower compression chamber 133S from the viewpoint of obtaining the effect of increasing the compression efficiency of the refrigerant in the upper compression chamber 133T and the lower compression chamber 133S. It is preferable to arrange so as to.

  The compressor 10 is provided with sliding part temperature detecting means for detecting the temperature of the sliding parts 137T and 137S. In this embodiment, an outer temperature sensor 170 for detecting the outer temperature of the compressor is provided on the side surface of the compressor housing 100 as the sliding part detecting means. Since the outer temperature sensor 170 is used when the detection result is used to estimate the temperature of the sliding portions 137T and 137S, it is desirable that the outer temperature sensor 170 be disposed at a location where the heat of the sliding portions 137T and 137S is easily transmitted. For example, when the upper cylinder 121T or the lower cylinder 121S is fixed to the inner wall of the compressor casing 100 in a shrink-fit state, the outer temperature sensor is attached to the outer wall surface of the compressor casing 100 corresponding to the upper cylinder 121T or the lower cylinder 121S. 170 is provided. A temperature sensor may be provided directly on the upper end plate 160T and the lower end plate 160S in the vicinity of the sliding portions 137T and 137S.

  Hereinafter, the flow of the refrigerant due to the rotation of the rotating shaft 150 will be described. In the upper cylinder chamber 130T, the rotation of the rotation shaft 150 causes the upper piston 125T fitted to the rotation shaft 150 to revolve along the outer peripheral surface of the upper cylinder chamber 130T (the inner peripheral surface of the upper cylinder 121T). The upper suction chamber 131T sucks the refrigerant from the upper suction pipe 105 while increasing the volume, the upper compression chamber 133T compresses the refrigerant while reducing the volume, and the compressed refrigerant passes through the upper discharge hole 190T to compress the compressor. It is discharged into the body 100.

  In the lower cylinder chamber 130S, the rotation of the rotation shaft 150 causes the lower piston 125S fitted to the rotation shaft 150 to revolve along the outer peripheral surface of the lower cylinder chamber 130S (the inner peripheral surface of the lower cylinder 121S). . Accordingly, the lower suction chamber 131S sucks the refrigerant from the lower suction pipe 104 while increasing the volume, the lower compression chamber 133S compresses the refrigerant while reducing the volume, and the compressed refrigerant is compressed through the lower discharge hole 190S. It is discharged into the machine casing 100.

  The refrigerant discharged into the compressor casing 100 is notched (not shown) provided on the outer periphery of the stator 111 and communicated with the upper and lower sides, or a gap (not shown) between winding portions of the stator 111, or the stator 111. Through the gap between the rotor 112 and the rotor 112 (not shown), and is discharged to the upper side of the motor 110 and discharged from a discharge pipe 107 serving as a discharge portion disposed in the upper portion of the compressor casing 100.

(Characteristic control of air conditioner)
Next, characteristic control of the air conditioner 1 according to the embodiment will be described. FIG. 4 is a control flowchart of the air conditioning apparatus of the embodiment. In the flowchart shown in FIG. 4, ST represents a process step, and the number following this represents a step number. In FIG. 4, processing related to the present invention is mainly described, and description of general processing such as control corresponding to an operating condition such as a set temperature and an air volume instructed by the user is omitted.

  The process according to the flowchart of FIG. 4 is repeatedly performed while the compressor 10 of the air conditioner 1 is being driven. First, the outdoor unit controller 200 estimates the temperature T0 of the sliding surfaces 137T and 137S based on the compressor outer temperature detected by the outer temperature sensor 170 (ST10). The outdoor unit control unit 200 includes a table 210 that is determined in advance by a test or the like regarding the relationship between the sliding surface temperature T0 and the compressor outer temperature. The outdoor unit control part 200 which finished the process of step ST10 determines whether the solenoid valve 26 is a closed state (ST11). When the solenoid valve 26 is in the closed state (ST11-YES), the process proceeds to step ST12 to determine whether or not the sliding part temperature T0 is equal to or higher than the first threshold temperature T1. The first threshold temperature T1 is determined in advance by a test or the like, and is stored in a storage unit (not shown) of the outdoor unit control unit 200.

  Here, the first threshold temperature T1 will be described with reference to FIG. FIG. 5 is a graph showing the pressure and temperature at which HFO 1123 causes a disproportionation reaction. A region 71 in FIG. 5 represents a region of temperature and pressure of the atmosphere of HFO 1123 in which HFO 1123 causes a disproportionation reaction. A curved line 72 indicates the boundary of the region 71. A region 71 is a region above the curve 72. The lower temperature limit 73 in FIG. 5 is a temperature lower than the curve 72 that is determined in advance by a test or the like and does not cause a disproportionation reaction even at the maximum refrigerant pressure assumed in the air-conditioning apparatus 1. The pressure lower limit 74 in FIG. 5 is a pressure lower than the curve 72 that is determined in advance by a test or the like and does not cause a disproportionation reaction even at the maximum temperature of the refrigerant assumed in the air conditioner 1.

  The graph of FIG. 5 shows that the HFO 1123 does not cause a disproportionation reaction when either the temperature or pressure of the atmosphere of the HFO 1123 is not included in the region 71. That is, the graph of FIG. 5 shows that HFO 1123 does not cause a disproportionation reaction at a temperature lower than the temperature lower limit value 73, and shows that HFO 1123 does not cause a disproportionation reaction at a pressure lower than the pressure lower limit value 74. Yes.

The outdoor unit control unit 200 sets the temperature lower limit value 73 or a temperature lower than the temperature lower limit value 73 to the first threshold temperature T1, and when the sliding surface temperature T0 becomes equal to or higher than the first threshold temperature T1 (ST12-YES), The electromagnetic valve 26 is opened, the liquid injection connecting pipe 46 is opened, and liquid refrigerant is directly supplied from the injection ports 141T and 141S of the respective injection holes 140a to the vicinity of the sliding portions 137T and 137S, and the sliding surfaces 137T, 137S is cooled (ST14). As a result, even if the sliding surface temperature T0 approaches the temperature at which the refrigerant generates a disproportionation reaction, the solenoid valve 26 is controlled to open at a temperature at which the disproportionation reaction does not occur in the refrigerant. Generation of the leveling reaction can be suppressed. Thereafter, the outdoor unit control unit 200 ends this control and performs the process from step ST10 again.
When the electromagnetic valve 26 is in the open state in step ST11 (ST11-NO), the outdoor unit control unit 200 proceeds to step ST13 and determines whether or not the sliding unit temperature T0 is equal to or lower than the second threshold temperature T2. To do. The second threshold temperature T2 is a temperature determined by providing a predetermined hysteresis difference from the first threshold temperature T1, and may be, for example, T1−T2 = 2 ° C.

  When the sliding surface temperature T0 becomes equal to or lower than the second threshold temperature T2 (ST13-YES), the outdoor unit control unit 200 determines that the sliding unit temperature is low and does not need to be cooled, and closes the solenoid valve 26. The cooling of the sliding surfaces 137T and 137S is stopped (ST15). After that, the outdoor unit control unit 200 repeats the process from step ST10 again after completing this control.

In step ST12, the outdoor unit control unit 200 determines that the sliding surface temperature T0 is equal to or lower than the first threshold temperature T1 (ST12-NO), or the sliding surface temperature T0 is higher than the second threshold temperature T2 (ST13). -NO), outdoor unit control part 200 repeats processing from Step ST10 again after this control is completed.

  Thus, the air conditioner 1 in the embodiment includes the refrigerant circuit 1a in which the compressor 10, the outdoor heat exchanger 23, the expansion device 24, and the indoor heat exchanger 51 are sequentially connected, and the refrigerant circulates therein. An air conditioner 1 having an outdoor unit 2 provided with a compressor 10 and an outdoor heat exchanger 23, an indoor unit 5 provided with an indoor heat exchanger 51, and an outdoor unit control unit 200, and in the refrigerant circuit 1a Liquid injection connecting pipe 46 for supplying liquid refrigerant to sliding parts 137T and 137S of compressor 10, electromagnetic valve 26 provided in liquid injection connecting pipe 46, and sliding part for detecting sliding part temperature T0 of the compressor The outdoor unit control unit 200 includes a temperature detection unit (outer temperature sensor 170) so that the sliding unit temperature T0 of the compressor 10 becomes the first threshold temperature T1 that is a temperature at which the disproportionation reaction does not occur in the refrigerant. Open / close control of solenoid valve 26 There. As a result, the sliding surfaces 137T and 137S can be cooled by the liquid refrigerant, so that the disproportionation reaction can be prevented from occurring in the refrigerant.

  In the present embodiment, the first threshold temperature T1 is set to a temperature at which the sliding portion temperature T0 of the compressor 10 does not cause a disproportionation reaction in the refrigerant regardless of the pressure of the refrigerant. However, it can be realized only with a temperature sensor.

  In this embodiment, when the sliding surface temperature T0 becomes equal to or higher than the first threshold temperature T1, the solenoid valve 26 is opened, the liquid injection connecting pipe 46 is opened, and the liquid refrigerant is injected into each injection hole 140a. Although the sliding surfaces 137T and 137S are cooled by supplying directly from the ports 141T and 141S to the vicinity of the sliding portions 137T and 137S, the present invention is not limited to this. For example, since the low-pressure side refrigerant sucked by the compressor 10 gradually disappears during the pump down operation, the refrigerant that cools the compressor 10 disappears, and the sliding portion temperature T0 is likely to rise. Regardless of the temperature T0, the service person may operate the operating means (not shown) of the air conditioner 1 to control the opening of the electromagnetic valve 26. In this case, the outer temperature sensor 170 is not necessary.

  In the present embodiment, the expansion device 24 is disposed in the outdoor unit 2, but is not limited thereto, and may be disposed in the indoor unit 5, for example.

  Further, one connection position of the liquid injection connecting pipe 46 is not between the outdoor heat exchanger 23 and the expansion device 24 in the refrigerant pipe 45 but between the expansion device 24 and the liquid side shut-off valve 61 in the refrigerant pipe 45. good. Normally, the liquid side closing valve 61 is closed during the pump down operation. In this case, the liquid side closing valve 61 is opened and the expansion device 24 is fully closed. Since the refrigerant on the indoor unit 5 side can be supplied to the compressor 10 from the liquid injection connection pipe 46, the operation time of the pump-down operation can be shortened.

DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 2 Outdoor unit 5 Indoor unit 10 Rotary compressor 100 Compressor housing 110 Motor 120 Compression part 150 Rotating shaft 25 Accumulator 105 Upper suction pipe (suction part)
104 Lower suction pipe (suction part)
107 Discharge pipe (discharge section)
121T Upper cylinder 121S Lower cylinder 125T Upper piston 125S Lower piston 127T Upper vane 127S Lower vane 128T Upper vane groove 128S Lower vane groove 130T Upper cylinder chamber 130S Lower cylinder chamber 131T Upper suction chamber 131S Lower suction chamber 133T Upper compression chamber 133S Lower compression chamber 135T Upper suction hole 135S Lower suction hole 137T, 137S Sliding surface 140 Intermediate partition plate 140a Injection hole 141T, 141S Injection port 142 Injection pipe 151 Subshaft portion 152T Upper eccentric portion 152S Lower eccentric portion 153 Main shaft portion 160T Upper end plate 160S Lower end plate 161T Main bearing portion 161S Sub bearing portion 190T Upper discharge hole 190S Lower discharge hole

Claims (4)

A compressor, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger are sequentially connected, and has a refrigerant circuit in which refrigerant circulates;
An air conditioner having an outdoor unit including the compressor and the outdoor heat exchanger, an indoor unit including the indoor heat exchanger, and a control unit,
A liquid injection connecting pipe for supplying the liquid refrigerant in the refrigerant circuit to the sliding portion of the compressor, and an electromagnetic valve provided in the liquid injection connecting pipe,
A sliding part temperature detecting means for detecting a sliding part temperature of the compressor;
The control means includes
The air conditioner is characterized in that the electromagnetic valve is controlled so that the sliding part temperature becomes a temperature at which a disproportionation reaction does not occur in the refrigerant. The said sliding part temperature detection means is an outer temperature sensor which detects the outer temperature of the said compressor, Comprising: The said sliding part temperature is estimated from the outer temperature of the said compressor. Air conditioner. The air conditioner according to claim 1 or 2, wherein the control unit controls the opening of the electromagnetic valve during a pump down operation of the air conditioner.   The air conditioner according to any one of claims 1 to 3, wherein the refrigerant is HFO1123 refrigerant or a mixed refrigerant containing HFO1123 refrigerant.

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