JP6624809B2 - Compressor and heat pump device provided with the compressor - Google Patents

Description

  The present invention relates to a compressor for compressing a refrigerant, and a heat pump device including the compressor.

  Conventionally, a heat pump device used for an air conditioner, a refrigerator, and the like has a refrigerant circuit in which a compressor, a condenser, an expansion mechanism, and an evaporator are connected by refrigerant piping. In such a heat pump device, when the electric motor mounted on the compressor is driven, the refrigerant in the refrigerant circuit is compressed by the compressor and discharged from the compressor. The refrigerant discharged from the compressor is condensed by the condenser, decompressed by the expansion mechanism, evaporated by the evaporator, and sucked into the compressor again. During operation of the compressor, the pressure in the refrigerant circuit becomes a positive pressure higher than the atmospheric pressure between the discharge port of the compressor and the inlet of the expansion mechanism, and the pressure between the outlet of the expansion mechanism and the suction port of the compressor. The pressure becomes lower than the atmospheric pressure. Therefore, when a hole is formed in the refrigerant pipe serving as a refrigerant flow path from the outlet of the expansion mechanism to the suction port of the compressor due to corrosion or poor welding, air may be mixed into the refrigerant circuit.

  Further, for example, air may be mixed into the refrigerant circuit due to an improper assembly of the heat pump device or an artificial cause such as an impact at the time of installing or removing the heat pump device.

  The air mixed in the refrigerant circuit is mixed with the refrigerant in the refrigerant circuit to form an air-fuel mixture. When a flammable refrigerant such as isobutane, propane, or R32 is used as the refrigerant, a flammable mixture may be formed when the refrigerant and air are mixed. Further, the air mixed in the refrigerant circuit is mixed with steam or mist lubricating oil in the refrigerant circuit to form an air-fuel mixture. When a flammable lubricating oil is used, a flammable mixture may be formed when the refrigerant and the lubricating oil are mixed.

  That is, when at least one of the refrigerant and the lubricating oil has flammability, if air enters the refrigerant circuit, a flammable air-fuel mixture may be generated. If the operation of the compressor causes the refrigerant or the lubricating oil to reach high temperature and high pressure, and the combustible mixture ignites or ignites, the compressor or the heat pump device may be damaged.

  Patent Document 1 includes an oxygen adsorbent made of reduced iron or activated carbon, a case for storing the oxygen adsorbent, and a permeable plate that permeates oxygen in the refrigeration cycle and separates the oxygen adsorbent from the refrigeration cycle. A refrigeration cycle to which an oxygen absorbing device is connected is described. This document describes that when air is mixed into the refrigeration cycle, oxygen in the mixed air reacts with the oxygen adsorbent and is absorbed, so that high reliability for explosion protection is obtained.

JP 2000-320911 A

  However, in the refrigeration cycle of Patent Document 1, oxygen is mixed into the refrigerant circuit at a mixing speed exceeding the adsorption speed of the oxygen adsorbent, or oxygen in an amount exceeding the adsorption capacity of the oxygen adsorbent is mixed into the refrigerant circuit. In this case, an increase in the combustible mixture in the refrigerant circuit cannot be suppressed. For this reason, when the combustible mixture ignites or ignites, there is a problem that damage to the compressor or the heat pump device cannot be prevented.

  The present invention has been made to solve the above-described problems, and includes a compressor that can prevent breakage even if a combustible air-fuel mixture ignites or ignites, and includes the compressor. It is an object of the present invention to provide a heat pump device.

The heat pump device according to the present invention includes a compressor, and a control unit that controls the compressor. The compressor includes a compression unit that compresses a refrigerant, an electric unit that drives the compression unit, and the compression unit. And a closed muffler that stores the lubricating oil and a cup muffler provided so as to cover a discharge port of the compression unit, and includes at least the refrigerant and the lubricating oil. One is flammable, and a temperature detecting unit is provided at a discharge port of the cup muffler, and the temperature detecting unit is located in the closed container, below the electric unit and the compression unit. Provided above the control unit , the control unit acquires information on the detected temperature detected by the temperature detection unit, and stops the electric unit when the detected temperature is higher than a preset set value. Is configured .
A compressor according to the present invention includes a compression unit that compresses a refrigerant, an electric unit that drives the compression unit, a closed container that stores the compression unit and the electric unit, and stores lubricating oil, A cup muffler provided so as to cover the discharge port of at least one of the refrigerant and the lubricating oil has flammability, and a temperature detection unit is provided at the discharge port of the cup muffler. The temperature detector is provided in the closed container, below the electric unit and above the compressor, and the temperature detector constitutes a part of an electric circuit for driving the compressor. Temperature fuse .

  A heat pump device according to the present invention includes the compressor according to the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, even if a combustible air-fuel mixture ignites or ignites, damage of a compressor or a heat pump apparatus can be prevented.

FIG. 1 is a refrigerant circuit diagram illustrating a schematic configuration of a heat pump device 100 according to Embodiment 1 of the present invention. 1 is a longitudinal sectional view illustrating a schematic configuration of a compressor 1 according to Embodiment 1 of the present invention. FIG. 2 is a side view illustrating an example of a configuration of a temperature detection unit 10 in the compressor 1 according to Embodiment 1 of the present invention. FIG. 3 is a top view illustrating an example of a positional relationship between the detection end 41 of the temperature detection unit 10 and the cup muffler 31 in the compressor 1 according to Embodiment 1 of the present invention. FIG. 3 is a side view illustrating an example of a positional relationship between a detection end 41 of the temperature detection unit 10 and the cup muffler 31 in the compressor 1 according to Embodiment 1 of the present invention. 3 is a flowchart illustrating an example of a process executed by a control unit 50 of the compressor 1 according to Embodiment 1 of the present invention. FIG. 4 is an explanatory diagram illustrating a relationship between a pressure and a temperature of a combustible mixture including a combustible refrigerant. 3 is a graph illustrating an example of a change over time of a detected temperature detected by a temperature detecting section 10 of the compressor 1 according to Embodiment 1 of the present invention.

Embodiment 1 FIG.
A compressor according to Embodiment 1 of the present invention and a heat pump device including the compressor will be described. FIG. 1 is a refrigerant circuit diagram illustrating a schematic configuration of a heat pump device 100 according to the present embodiment. In the following drawings including FIG. 1, the relative dimensional relationships, shapes, and the like of the components may be different from actual ones.

[Heat pump device 100]
The heat pump device 100 is used as a heat source device used for a refrigerating device such as an air conditioner, a refrigerator, or a water heater. In the present embodiment, a heat pump device 100 used in an air conditioner and capable of switching between a cooling operation and a heating operation is illustrated.

  As shown in FIG. 1, the heat pump device 100 includes a compressor 1 that compresses and discharges a refrigerant, a muffler 6 that reduces pulsation of the refrigerant discharged from the compressor 1, and a four-way valve 5 that switches a flow path of the refrigerant. A first heat exchanger 2 (heat source side heat exchanger) functioning as a radiator or an evaporator, an expansion mechanism 3 for decompressing high-pressure refrigerant, and a second heat exchanger 4 functioning as an evaporator or a radiator. (Load-side heat exchanger) and an accumulator 7 for storing excess refrigerant. The heat pump device 100 has a refrigerant pipe 9 that connects the compressor 1, the muffler 6, the four-way valve 5, the first heat exchanger 2, the expansion mechanism 3, the second heat exchanger 4, the accumulator 7, and the like. . Hereinafter, among the refrigerant pipes 9, the refrigerant pipe between the compressor 1 and the four-way valve 5 may be referred to as a discharge refrigerant pipe 9A. Further, among the refrigerant pipes 9, the refrigerant pipe between the accumulator 7 and the compressor 1 may be referred to as a suction refrigerant pipe 9B.

  In the present embodiment, a flammable refrigerant (for example, isobutane, propane, R32, or the like) is used as the refrigerant circulating in the refrigerant flow path of the heat pump device 100. In addition, flammable lubricating oil is used as lubricating oil stored in the sealed container 11 of the compressor 1. Here, the refrigerant flow path is a refrigerant circuit configured by the compressor 1, the muffler 6, the four-way valve 5, the first heat exchanger 2, the expansion mechanism 3, the second heat exchanger 4, the accumulator 7, and the refrigerant pipe 9. It is.

[First heat exchanger 2]
The first heat exchanger 2 exchanges heat between a refrigerant flowing inside and an external fluid (for example, outdoor air). The first heat exchanger 2 functions as an evaporator that absorbs heat from the external fluid to evaporate the refrigerant during the heating operation, and a radiator (for example, a condenser) that absorbs heat from the refrigerant and releases the heat to the external fluid during the cooling operation. Function as As the first heat exchanger 2, for example, a plate fin and tube heat exchanger including a plurality of plate fins provided in parallel with each other and a plurality of tubes provided through the plurality of plate fins Is used. One of the two refrigerant ports provided in the first heat exchanger 2 is connected to the four-way valve 5 via the refrigerant pipe 9, and the other is connected to the expansion mechanism 3 via the refrigerant pipe 9. . The first heat exchanger 2 is housed in, for example, an outdoor unit installed outdoors. The outdoor unit houses a blower fan (not shown) that blows outdoor air to the first heat exchanger 2 and promotes heat exchange between the refrigerant and the outdoor air.

[Expansion mechanism 3]
The expansion mechanism 3 decompresses and expands the refrigerant. One of the two refrigerant ports provided in the expansion mechanism 3 is connected to the first heat exchanger 2 via the refrigerant pipe 9, and the other is connected to the second heat exchanger 4 via the refrigerant pipe 9. Have been. As the expansion mechanism 3, an expansion valve such as an electronic expansion valve whose opening can be variably adjusted, or a fixed throttle such as a capillary tube can be used.

[Second heat exchanger 4]
The second heat exchanger 4 exchanges heat between a refrigerant flowing inside and an external fluid (for example, indoor air). The second heat exchanger 4 functions as a radiator (for example, a condenser) that absorbs heat from the refrigerant and radiates heat to the external fluid during the heating operation, and evaporator that absorbs heat from the external fluid and evaporates the refrigerant during the cooling operation. Function as As the second heat exchanger 4, for example, a plate fin and tube heat exchanger is used. One of the two refrigerant ports provided in the second heat exchanger 4 is connected to the four-way valve 5 via the refrigerant pipe 9, and the other is connected to the expansion mechanism 3 via the refrigerant pipe 9. . The second heat exchanger 4 is housed in, for example, an indoor unit installed indoors. The indoor unit houses a blower fan (not shown) that blows indoor air to the second heat exchanger 4 to promote heat exchange between the refrigerant and the indoor air and supplies air-conditioned air to the space to be air-conditioned. I have.

[Four-way valve 5]
The four-way valve 5 switches a flow path of the high-pressure refrigerant discharged from the compressor 1 to a flow path toward the first heat exchanger 2 or a flow path toward the second heat exchanger 4. The four-way valve 5 switches the flow path so that the high-pressure refrigerant discharged from the compressor 1 is supplied to the second heat exchanger 4 during the heating operation, and the high-pressure refrigerant discharged from the compressor 1 during the cooling operation. Are switched so that is supplied to the first heat exchanger 2. FIG. 1 shows the flow path during the cooling operation.

[Muffler 6]
The muffler 6 is provided on a discharge refrigerant pipe 9 </ b> A between the compressor 1 and the four-way valve 5. The muffler 6 reduces pulsation of the refrigerant discharged from the compressor 1. The muffler 6 has an upstream side in the refrigerant flow direction connected to the discharge side of the compressor 1, and a downstream side in the refrigerant flow direction connected to the four-way valve 5.

[Accumulator 7]
The accumulator 7 is provided in a suction refrigerant pipe 9B between the four-way valve 5 and the compressor 1. The accumulator 7 has a refrigerant storage function of storing the surplus refrigerant, and separates the low-pressure refrigerant flowing out of the evaporator (the first heat exchanger 2 or the second heat exchanger 4) into a liquid refrigerant and a gas refrigerant. And a gas-liquid separation function for preventing the liquid refrigerant from being sucked into the air.

[Compressor 1]
FIG. 2 is a longitudinal sectional view illustrating a schematic configuration of the compressor 1 according to the present embodiment. In the present embodiment, a vertical compressor 1 is illustrated. As shown in FIG. 2, the compressor 1 includes a compression unit 15 that compresses a refrigerant, an electric unit 13 that drives the compression unit 15, and a sealed container 11 that houses the compression unit 15 and the electric unit 13. ing. The motor 13 and the compressor 15 are connected by a rotating shaft 14.

[Sealed container 11]
The closed container 11 constitutes an outer shell of the compressor 1. A compression section 15 and a stator 16 of an electric section 13 disposed above the compression section 15 are fixed to the inner wall surface of the closed casing 11. A discharge port 11a and a suction port 11b, which are openings, are formed in the closed container 11. A discharge refrigerant pipe 9 </ b> A that discharges the high-pressure refrigerant compressed by the compression unit 15 from the inside of the closed container 11 to the outside is connected to the discharge port 11 a of the closed container 11. A suction refrigerant pipe 9B for supplying a low-pressure refrigerant to the compression unit 15 is connected to a suction port 11b of the closed casing 11. In this example, the pressure in the internal space of the closed container 11 is the discharge pressure.

  A lubricating oil reservoir 12 is formed at the bottom of the closed container 11. The lubricating oil reservoir 12 stores lubricating oil for reducing sliding friction in the compression section 15. The lubricating oil stored in the lubricating oil reservoir 12 is sucked into the compression section 15 together with the refrigerant, and is supplied to a sliding section in the compression section 15.

[Electric part 13]
The electric unit 13 includes a stator 16 fixed to the closed casing 11, and a rotor 17 arranged on the inner peripheral side of the stator 16. The stator 16 has a configuration in which a multi-phase winding 21 is mounted on a laminated iron core 19. A plurality of oil return holes 18 penetrating in the axial direction (only one oil return hole 18 is shown in FIG. 2) is formed in the laminated iron core 19. The outer peripheral surface of the stator 16 is fixed to the inner peripheral surface of the closed casing 11. The outer peripheral surface of the rotor 17 and the inner peripheral surface of the stator 16 face each other with a predetermined gap therebetween. A rotating shaft 14 is coaxially fixed to the inner peripheral side of the rotor 17. When electric power is supplied to the stator 16 from a power supply (not shown), the rotor 17 rotates. This rotation driving force is transmitted to the compression unit 15 via the rotation shaft 14. In the compression section 15, the refrigerant is compressed by the transmitted rotational driving force.

[Compression unit 15]
The compression section 15 compresses the refrigerant drawn into the closed container 11. As the compression unit 15, various compression mechanisms (for example, a rotary type, a scroll type, a vane type, etc.) can be adopted. Here, a rotary compression mechanism will be described as an example.

  The compression unit 15 includes a hollow cylinder 24, a roller 26 disposed in a space inside the cylinder 24, and a vane 27 that abuts on an outer peripheral surface of the roller 26 to divide the space inside the cylinder 24 into a compression chamber and a suction chamber. And an upper bearing portion 28 and a lower bearing portion 29 that rotatably support the rotating shaft 14.

  The upper end side of the rotating shaft 14 is connected to the rotor 17 of the electric unit 13. The lower end of the rotary shaft 14 is rotatably supported by the upper bearing 28 and the lower bearing 29 of the compression unit 15. The rotation shaft 14 rotates around an axis parallel to the vertical direction. The rotary shaft 14 is provided with an eccentric part 25 having a central axis at a position shifted from the central axis of the rotary shaft 14. The eccentric part 25 is located in a space inside the cylinder 24. When the rotation shaft 14 rotates, the eccentric part 25 rotates eccentrically in the space inside the cylinder 24.

  The roller 26 is a ring-shaped member. An eccentric portion 25 of the rotating shaft 14 is slidably fitted on the inner peripheral side of the roller 26. The roller 26 eccentrically rotates along the inner peripheral surface of the cylinder 24 due to the eccentric rotation of the eccentric portion 25.

  The vane 27 is slidably accommodated in a vane groove (not shown) formed along the radial direction of the cylinder 24. The vane 27 reciprocates in the vane groove following the eccentric rotation of the roller 26.

  The upper bearing portion 28 also serves as an end plate that closes an upper end portion (an end portion on the electric unit 13 side) of the space in the cylinder 24. The lower bearing portion 29 also serves as an end plate that closes a lower end portion (an end portion on the lubricating oil reservoir 12 side) of the space in the cylinder 24.

  A compression chamber, which is a space in which the refrigerant is compressed, is formed by the cylinder 24, the rollers 26, the vanes 27, and the like. With the eccentric rotation of the roller 26, the volume of the compression chamber becomes smaller. Thereby, the refrigerant supplied to the compression chamber is compressed.

  The discharge port 15 a of the compression section 15 is formed in the upper bearing section 28. The discharge port 15a is provided with a discharge valve 30 that opens when the pressure in the compression chamber becomes equal to or higher than a preset pressure.

  A cup muffler 31 is provided on the upper surface of the upper bearing portion 28 so as to cover the discharge port 15a of the compression portion 15 and the discharge valve 30. The cup muffler 31 is formed in a substantially circular cup shape using a conductive material. Inside the cup muffler 31 (that is, between the cup muffler 31 and the upper bearing portion 28), a muffler chamber for reducing pulsation of the refrigerant discharged from the discharge port 15a is formed. The muffler chamber in the cup muffler 31 communicates with the internal space of the closed container 11 via a discharge port 31a formed in the cup muffler 31. The outlet 31a of the cup muffler 31 is provided with a temperature detector 10 described later. The temperature detecting section 10 is provided in the closed container 11 below the electric section 13 and above the compressing section 15.

  The low-pressure refrigerant supplied to the compression section 15 via the suction refrigerant pipe 9B is compressed in the compression chamber of the compression section 15. The high-pressure refrigerant compressed in the compression chamber is once discharged from the discharge port 15a to a muffler chamber in the cup muffler 31, and then discharged from the discharge port 31a of the cup muffler 31 to the internal space of the closed container 11. The high-pressure refrigerant discharged into the internal space of the closed container 11 is supplied to a space above the electric unit 13 through a gap or the like between the stator 16 and the rotor 17, and is supplied to a discharge port 11 a of the closed container 11. The refrigerant is discharged to the outside of the compressor 1 through the connected discharge refrigerant pipe 9A.

[Temperature detector 10]
The temperature detector 10 detects the temperature at the discharge port 31a of the cup muffler 31 (for example, the temperature of the high-pressure refrigerant discharged from the discharge port 31a). Further, the temperature detection unit 10 can also detect a temperature rise due to heat generation of a flame described later. As the temperature detecting unit 10, for example, a thermocouple for detecting electromotive force, a resistance temperature detector for detecting electric resistance, or the like is used. Thermocouples are formed by connecting both ends of two different types of metal wires to form a closed circuit. When a temperature difference occurs at both ends, a thermoelectric power unique to the metal is generated by the Seebeck effect, and a current flows in a closed circuit. There are various types of thermocouples depending on the combination of the two types of metal wires. A sheath-type thermocouple in which two types of metal wires are covered with an insulating material and a protective tube is easy to handle. The resistance temperature detector utilizes the characteristic that the electrical resistance of a metal changes with temperature. Some of the resistance temperature detectors also include a sheath type in which the periphery of the resistance element is covered with an insulating material and a protective tube.

  FIG. 3 is a side view showing an example of a configuration of the temperature detecting unit 10 in the compressor 1 according to the present embodiment. FIG. 3 illustrates the temperature detection unit 10 using a thermocouple or a resistance temperature detector. As shown in FIG. 3, the temperature detection unit 10 has a detection end 41 having a cylindrical rod shape, and an attachment portion 42 having an outer diameter larger than the detection end 41 and penetrating the detection end 41. ing. The detection end 41 includes, for example, a protection tube, an insulating material, and a detection element (a thermocouple or a resistance temperature detector). The mounting portion 42 is inserted into a through-hole formed in the body of the closed container 11 and is hermetically joined to the closed container 11 by welding or the like.

  FIG. 4 is a top view illustrating an example of a positional relationship between the detection end 41 of the temperature detection unit 10 and the cup muffler 31 in the compressor 1 according to the present embodiment. FIG. 5 is a side view illustrating an example of a positional relationship between the detection end 41 of the temperature detection unit 10 and the cup muffler 31 in the compressor 1 according to the present embodiment. As shown in FIGS. 4 and 5, the detection end 41 of the temperature detection unit 10 is disposed at the discharge port 31 a of the cup muffler 31. More precisely, at least a part of the detection end 41 is arranged outside the muffler chamber formed in the cup muffler 31 and directly above the discharge port 31a of the cup muffler 31.

  In this example, the temperature detector 10 using a thermocouple or a resistance temperature detector is illustrated, but the temperature detector 10 is not limited thereto. The temperature detection unit 10 may use a radiation temperature sensor or the like that detects infrared rays. Further, in this example, the temperature detection unit 10 using the sheath-type thermocouple is illustrated, but two types of metal wires can be used as the detection end 41 as they are. Further, in this example, the detection end 41 of the temperature detection unit 10 has a cylindrical rod shape, but the detection end 41 may have another shape such as a flat bar shape.

[Control unit 50]
Returning to FIG. 1, the temperature detection unit 10 is connected to the control unit 50 via the wiring 51. The control unit 50 has a microcomputer including a CPU, a ROM, a RAM, an input / output port, and the like. The control unit 50 acquires information on the detected temperature from the electromotive force and the electric resistance of the temperature detection unit 10. The control unit 50 of the present example also serves as a control device that controls the operations of the compressor 1 and the heat pump device 100 including the same.

  FIG. 6 is a flowchart illustrating an example of a process executed by control unit 50 of compressor 1 according to the present embodiment. The process shown in FIG. 6 is repeatedly executed at predetermined time intervals during the operation period of the compressor 1, for example. In step S1 of FIG. 6, information on the temperature detected by the temperature detecting unit 10 is acquired based on the electromotive force and the electric resistance of the temperature detecting unit 10. Next, in step S2, it is determined whether or not the acquired detected temperature is higher than a preset set value (described later). If it is determined that the detected temperature is higher than the set value, the process proceeds to step S3, and if it is determined that the detected temperature is equal to or lower than the set value, the process ends.

  In step S3, a process of stopping the electric unit 13 of the compressor 1 is performed. By this process, the compressor 1 stops. Thereafter, a process of prohibiting the restart of the electric unit 13 may be performed (step S4). By this processing, restart of the stopped compressor 1 is prohibited.

[Operation of heat pump device 100]
The operation of the heat pump device 100 configured as described above during the cooling operation will be described. During the cooling operation, the four-way valve 5 is switched so that the refrigerant flow path shown in FIG. 1 is formed. The high-temperature and high-pressure gas refrigerant compressed by the compressor 1 is discharged to the discharge refrigerant pipe 9A and flows into the first heat exchanger 2 via the muffler 6 and the four-way valve 5. During the cooling operation, the first heat exchanger 2 functions as a condenser. That is, in the first heat exchanger 2, heat exchange between the refrigerant flowing inside and the outdoor air blown by the blower fan is performed, and the heat of condensation of the refrigerant is radiated to the outdoor air. Thereby, the refrigerant flowing into the first heat exchanger 2 is condensed and becomes a high-pressure liquid refrigerant. The high-pressure liquid refrigerant flows into the expansion mechanism 3 and is reduced in pressure to become a low-pressure two-phase refrigerant.

  The low-pressure two-phase refrigerant decompressed by the expansion mechanism 3 flows into the second heat exchanger 4. During the cooling operation, the second heat exchanger 4 functions as an evaporator. That is, in the second heat exchanger 4, heat exchange between the refrigerant flowing inside and the room air blown by the blower fan is performed, and the heat of evaporation of the refrigerant is absorbed from the room air. Thereby, the refrigerant flowing into the second heat exchanger 4 evaporates and becomes a low-pressure gas refrigerant or a two-phase refrigerant. Further, the air blown by the blower fan is cooled by the heat absorbing action of the refrigerant. The low-pressure gas refrigerant or the two-phase refrigerant flowing out of the second heat exchanger 4 flows into the accumulator 7 via the four-way valve 5 and is separated into gas and liquid by the accumulator 7. The gas refrigerant in the accumulator 7 is drawn into the compressor 1 via the suction refrigerant pipe 9B, and is compressed again. In the cooling operation, the above cycle is continuously repeated. Thereby, the space to be air-conditioned is cooled using the cold generated by the second heat exchanger 4.

  During the operation of the compressor 1, the pressure in the refrigerant circuit becomes a negative pressure lower than the atmospheric pressure between the outlet of the expansion mechanism 3 and the suction port 11 b of the compressor 1. Therefore, if a hole is formed in the refrigerant pipe from the outlet of the expansion mechanism 3 to the suction port 11b of the compressor 1 due to corrosion or poor welding, air may enter the refrigerant circuit. In addition, an assembly failure of the heat pump device 100 (for example, a displacement of a connection position between the refrigerant pipe 9 and the second heat exchanger 4 from a design position) or an artificial force such as an impact at the time of installing or removing the heat pump device 100 is performed. Air may be mixed into the refrigerant circuit depending on a specific cause.

  In the present embodiment, the refrigerant has flammability. Therefore, if the air mixed in the refrigerant circuit is mixed with the refrigerant, the air may become a combustible air-fuel mixture depending on the concentration of the refrigerant. For example, the flammable range of isobutane is 1.8 vol% to 8.4 vol% under atmospheric pressure. The flammable range of propane is 2.1 vol% to 9.5 vol% under atmospheric pressure. The flammable range of R32 is 13.3 vol% to 29.3 vol% under atmospheric pressure.

  In the present embodiment, the lubricating oil also has flammability. For this reason, if the air mixed in the refrigerant circuit is mixed with the vapor or mist of the lubricating oil, it may become a combustible air-fuel mixture.

  FIG. 7 is an explanatory diagram showing the relationship between the pressure and the temperature of the combustible mixture including the combustible refrigerant. The horizontal axis in FIG. 7 represents pressure, and the vertical axis represents temperature. In addition, the horizontal axis of FIG. 7 also represents the lapse of time when the pressure increases from the normal operation range. A curve A indicates a change in the pressure and temperature of the combustible mixture in the compressor 1, and a curve B indicates a change in the auto-ignition temperature of the combustible refrigerant. The auto-ignition temperature of isobutane is between 432 ° C and 470 ° C under atmospheric pressure. The auto-ignition temperature of propane is between 430C and 460C under atmospheric pressure. The autoignition temperature of R32 is 648 ° C. under atmospheric pressure. Generally, the self-ignition temperature of the refrigerant decreases as the pressure increases.

  The mixture containing the flammable refrigerant has a concentration in the flammable range, and the pressure and temperature in the compressor 1 increase due to the operation of the compressor 1 (curve A in FIG. 7). When the curve B) in FIG. 7 is reached, the combustible mixture in the compressor 1 self-ignites.

  Although the self-ignition temperature of a lubricating oil is not generally disclosed, when the self-ignition temperature of a certain lubricating oil was examined, the lubricating oil mist self-ignited at about 400 ° C. Although the self-ignition temperature differs depending on the type of the lubricating oil, it was found that the lubricating oil sometimes self-ignites at a lower temperature than the refrigerant. Therefore, for example, when the lubricating oil and the flammable refrigerant having isobutane are used in the heat pump device 100, the lubricating oil having a relatively low auto-ignition temperature may self-ignite first.

  The space where the flame is first formed during the operation of the compressor 1 is the discharge port 31 a of the cup muffler 31. The space above the fixed position of the compression unit 15 and below the fixed position of the electric unit 13 in the closed container 11 has a high pressure, and the discharge port 31a of the cup muffler 31 has the highest temperature. Therefore, since the combustible air-fuel mixture at the discharge port 31a of the cup muffler 31 reaches the self-ignition temperature first in the closed container 11, the flame is formed first at the discharge port 31a. That is, in the configuration of the present embodiment, temperature detection unit 10 is arranged in a space where a flame is first formed.

  FIG. 8 is a graph showing an example of a temporal change of the detected temperature detected by temperature detecting section 10 of compressor 1 according to the present embodiment. The horizontal axis of the graph represents the elapsed time [sec] when the time when the flame is formed is set to 0 second. The vertical axis represents the temperature [° C.]. As the temperature detecting unit 10, a sheath-type K (chromel-alumel) thermocouple having an outer diameter of 1 mm was used.

  As shown in FIG. 8, during normal operation of the compressor 1, the temperature detected by the temperature detection unit 10 varies depending on the type of the refrigerant, but is at most about 80 ° C. to 120 ° C. On the other hand, the temperature of the flame is generally 1000 ° C. or higher, and the adiabatic flame temperature when there is no heat loss is 2000 ° C. or higher. For this reason, when the combustible air-fuel mixture ignites and a flame is formed in the vicinity of the temperature detecting unit 10, the temperature detecting unit 10 detects an extremely high temperature as compared with during normal operation. Since not all of the heat of the flame is instantaneously transmitted to the temperature detector 10, there is a difference between the actual flame temperature and the temperature detected by the temperature detector 10. However, immediately after the flame is formed, the temperature detector 10 detects a temperature of about 500 ° C., which is extremely higher than the temperature during normal operation.

  When the high temperature due to the formation of the flame is detected by the temperature detection unit 10, the control unit 50 of the present embodiment stops driving the compressor 1. That is, when the temperature change as shown in FIG. 8 occurs, if the set value used as the threshold in step S2 in FIG. And the formation of a flame can be reliably detected.

  As described in step S4 of FIG. 6, when the controller 50 stops the compressor 1 upon detecting the formation of the flame, the controller 50 may prohibit the restart of the compressor 1. This is because, once a flame is generated, the internal components of the compressor 1 are exposed to high temperatures, and carbides such as soot due to the flame adhere to the internal components. In this case, when the heat pump device 100 is operated again, for example, replacement of the compressor 1 is performed.

  In the above example, a sheath-type K thermocouple having an outer diameter of 1 mm is used as the temperature detecting unit 10. However, since flame formation is an instantaneous phenomenon, in order to more reliably detect flame formation, it is desirable to reduce the outer diameter of the detection end 41 of the temperature detection unit 10 to reduce the heat capacity. Further, in order to reduce the heat capacity of the detection end 41, a bare thin wire thermocouple without a protection tube can be used. When a bare thin wire thermocouple is used, it is necessary to improve the heat resistance of the metal wire. Therefore, a platinum-based R (platinum-rhodium alloy-platinum: rhodium 13%) thermocouple that can be detected up to higher temperatures or S (Platinum rhodium alloy-platinum: rhodium 10%) It is desirable to use a thermocouple or the like.

  A temperature fuse may be used for the temperature detection unit 10. The thermal fuse normally functions as a conductor constituting a part of an electric circuit (for example, an electric circuit for driving the compressor 1 or an electric circuit for detecting the formation of a flame), and when the temperature becomes high, the element is melted. It cuts off the electric circuit. There are various operating temperatures of the thermal fuse, such as 70 ° C. to 240 ° C. By using a temperature fuse that operates at a higher temperature than the above-described maximum temperature of about 80 ° C. to 120 ° C. during normal operation, it is possible to avoid erroneous stop of the compressor 1 during normal operation. When a thermal fuse is used as the temperature detecting unit 10, after the thermal fuse operates due to flame formation, the compressor 1 is restarted unless the thermal fuse is replaced (for example, unless the compressor 1 itself is replaced). The configuration cannot be performed.

  As described above, the compressor 1 according to the present embodiment accommodates the compression unit 15 that compresses the refrigerant, the electric unit 13 that drives the compression unit 15, the compression unit 15 and the electric unit 13, and A closed container 11 for storing oil, and a cup muffler 31 provided so as to cover the discharge port 15a of the compression unit 15, wherein at least one of the refrigerant and the lubricating oil has flammability. The temperature detection unit 10 is provided at the discharge port 31a.

  In the conventional configuration, in the event that the combustible air-fuel mixture ignites or ignites in the closed container 11, a flame is repeatedly formed at the discharge port 31a of the cup muffler 31 having the highest pressure in the closed container 11, The temperature change as shown in FIG. 8 may be repeated. If the operation of the compressor 1 is continued in such a state in which the flame is repeatedly formed, not only the discharge port 31a of the cup muffler 31 but also the entire temperature in the closed container 11 reaches the self-ignition temperature, and the inside of the closed container 11 The flames can spread throughout the area. If the flame spreads in the closed container 11, the pressure in the closed container 11 becomes high, and the compressor 1 may be damaged depending on the pressure resistance of the closed container 11.

  On the other hand, according to the present embodiment, even if a flammable mixture is ignited or ignited in the sealed container 11 and a flame is formed, the discharge port 31a of the cup muffler 31 is Can be detected. For this reason, immediately after the flame is first formed in the closed container 11, for example, by stopping the compressor 1 (the electric unit 13), the pressure and the temperature in the closed container 11 can be reduced. Thereby, it is possible to prevent the first flame in the closed casing 11 from propagating to the entire compressor 1 or the refrigerant circuit of the heat pump device 100. Therefore, according to the present embodiment, damage to compressor 1 and heat pump device 100 can be prevented.

  Further, in the compressor 1 according to the present embodiment, the compressor 1 further includes a control unit 50 for acquiring information on the detected temperature detected by the temperature detection unit 10, and the control unit 50 sets the detected temperature to a preset value. It may be configured to stop the electric unit 13 when the value is higher than the value. According to this configuration, the compressor 1 can be reliably stopped immediately after the first flame is formed in the closed container 11.

  Further, in compressor 1 according to the present embodiment, control unit 50 may be configured to prohibit restart of electric unit 13 when electric unit 13 is stopped. According to this configuration, it is possible to prevent the compressor 1 from being operated in a state where the internal components of the compressor 1 are exposed to a high temperature or a carbide such as soot due to a flame adheres to the internal components. .

  Further, in compressor 1 according to the present embodiment, temperature detecting section 10 may include a sheath-type thermocouple.

  Further, in compressor 1 according to the present embodiment, temperature detection unit 10 may include a bare wire thermocouple (for example, a thin wire thermocouple).

  Further, in the compressor 1 according to the present embodiment, the thermocouple may be a platinum-based R thermocouple or an S thermocouple.

  Further, in compressor 1 according to the present embodiment, temperature detection unit 10 may include a thermal fuse (for example, a thermal fuse that constitutes a part of an electric circuit that drives compressor 1). According to this configuration, the compressor 1 can be reliably stopped immediately after the first flame is formed in the closed container 11. Further, according to this configuration, the compressor 1 cannot be restarted unless the thermal fuse (for example, the compressor 1 itself) is replaced. Therefore, it is possible to prevent, for example, a user from operating the compressor 1 in a state where the internal components are exposed to a high temperature or a carbide such as soot due to a flame adheres to the internal components.

  In the compressor 1 according to the present embodiment, the refrigerant may include at least one of isobutane, propane, and R32 as a composition.

  Further, a heat pump device 100 according to the present embodiment includes the compressor 1 described above. According to this configuration, it is possible to prevent the heat pump device 100 from being damaged.

Other embodiments.
The present invention is not limited to the above embodiment, and various modifications are possible.
For example, in the above-described embodiment, a configuration in which both the refrigerant and the lubricating oil have flammability has been described as an example, but the present invention is applicable to a configuration in which at least one of the refrigerant and the lubricating oil has flammability.

  Further, in the above embodiment, the vertical compressor is taken as an example, but the present invention is also applicable to a horizontal compressor.

  Further, the above-described embodiments and modifications can be implemented in combination with each other.

  DESCRIPTION OF SYMBOLS 1 Compressor, 2 1st heat exchanger, 3 Expansion mechanism, 4 2nd heat exchanger, 5 Four-way valve, 6 Muffler, 7 Accumulator, 9 Refrigerant piping, 9A Discharge refrigerant piping, 9B Suction refrigerant piping, 10 Temperature detection part , 11 closed container, 11a discharge port, 11b suction port, 12 lubricating oil reservoir, 13 motorized section, 14 rotating shaft, 15 compression section, 15a discharge port, 16 stator, 17 rotor, 18 oil return hole, 19 laminated iron core , 21 winding, 24 cylinder, 25 eccentric part, 26 roller, 27 vane, 28 upper bearing part, 29 lower bearing part, 30 discharge valve, 31 cup muffler, 31a discharge port, 41 detecting end, 42 mounting part, 50 control Part, 51 wiring, 100 heat pump device.

Claims (8)

A compressor, comprising a control unit for controlling the compressor,
The compressor is
A compression unit for compressing the refrigerant,
An electric unit that drives the compression unit;
A sealed container that houses the compression unit and the electric unit, and stores lubricating oil,
A cup muffler provided to cover a discharge port of the compression unit,
Has,
At least one of the refrigerant and the lubricating oil has flammability,
A temperature detection unit is provided at an outlet of the cup muffler,
The temperature detection unit is provided in the closed container, below the electric unit and above the compression unit,
A heat pump device configured to acquire information on a detected temperature detected by the temperature detecting unit, and to stop the electric unit when the detected temperature is higher than a preset set value; .   The heat pump device according to claim 1, wherein the control unit is configured to prohibit restart of the electric unit when the electric unit is stopped.   The heat pump device according to claim 1, wherein the temperature detection unit includes a sheath-type thermocouple.   The heat pump device according to claim 1, wherein the temperature detection unit includes a bare wire thermocouple.   The heat pump device according to claim 4, wherein the thermocouple is an R thermocouple or an S thermocouple.   The heat pump device according to any one of claims 1 to 5, wherein the refrigerant includes at least one of isobutane, propane, and R32 as a composition. A compression unit for compressing the refrigerant,
An electric unit that drives the compression unit;
A sealed container that houses the compression unit and the electric unit, and stores lubricating oil,
A cup muffler provided to cover a discharge port of the compression unit,
With
At least one of the refrigerant and the lubricating oil has flammability,
A temperature detector is provided at the outlet of the cup muffler,
The temperature detection unit is provided in the closed container, below the electric unit and above the compression unit,
The compressor, wherein the temperature detector has a temperature fuse that forms a part of an electric circuit that drives the compressor.   A heat pump device comprising the compressor according to claim 7.

Images