JP7292428B2 - refrigeration cycle equipment - Google Patents

Description

The present disclosure relates to a refrigeration cycle device having a refrigerant circuit with an oil injection circuit.

Conventionally, a refrigeration cycle device is known to have a scroll compressor having an injection passage for supplying oil to a compression chamber during compression. For example, in the oil-filled hermetic scroll compressor disclosed in Patent Document 1, part of the oil separated by an oil separator provided on the discharge side of the scroll compressor is injected through an oil feed pipe and an injection pipe. It is configured to supply the fuel from the injection port to the compression chamber. The compression chamber is formed by combining the fixed spiral teeth of the fixed scroll and the oscillating spiral teeth of the oscillating scroll so as to mesh with each other.

JP-A-5-5486

However, the lubricated hermetic scroll compressor disclosed in Patent Document 1 is not configured to control the amount of oil injected into the compression chambers, so oil is always injected into the compression chambers. Therefore, in a scroll compressor operated by inverter control, the higher the operating frequency becomes, the more oil is taken into the compression chamber. There is concern about performance degradation due to an increase in

The present disclosure has been made to solve the above problems, and an object thereof is to provide a refrigeration cycle apparatus capable of controlling the amount of oil injected into the compression chamber.

A refrigeration cycle device according to the present disclosure includes a scroll compressor having a compression chamber for compressing a refrigerant and an injection pipe connected to the compression chamber, an oil separator, a first heat exchanger, a pressure reducing device, a second A heat exchanger is connected in order by pipes to operate a main circuit in which refrigerant circulates, an oil injection circuit branched from the oil separator and connected to the injection pipe of the scroll compressor, and a refrigeration cycle device. a first oil injection circuit branched from the oil separator and connected to the injection pipe of the scroll compressor via the first heat exchanger; and , a second oil injection circuit branched from the oil separator and connected to the injection pipe of the scroll compressor via the second heat exchanger, the first oil injection circuit and the second 2. Each of the oil injection circuits is provided with a first control valve that is controlled by the control device and adjusts the flow rate of the oil flowing through the oil injection circuit. Oil injection is performed by closing the first control valve and opening the first control valve during low-speed operation of the scroll compressor.

According to the refrigeration cycle apparatus of the present disclosure, the oil injection circuit is provided with the first control valve that adjusts the flow rate of oil, so the flow rate and timing of injection of oil into the compression chamber can be controlled. Therefore, in a state where the operating frequency of the scroll compressor is in a high speed range, the amount of oil supplied to the compression chamber can be adjusted. It is possible to suppress the deterioration in performance due to the increase.

1 is a refrigerant circuit diagram of a refrigeration cycle device according to Embodiment 1. FIG. 1 is a schematic longitudinal sectional view showing a scroll compressor that is a component of a refrigeration cycle apparatus according to Embodiment 1; FIG. FIG. 7 is a refrigerant circuit diagram of a refrigeration cycle device according to Embodiment 2; FIG. 7 is a refrigerant circuit diagram of a refrigeration cycle device according to Embodiment 3; FIG. 11 is a refrigerant circuit diagram of a refrigeration cycle device according to Embodiment 4; FIG. 11 is a refrigerant circuit diagram of a refrigeration cycle device according to Embodiment 5;

Embodiments of the present disclosure will be described below with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will be omitted or simplified as appropriate. Further, the shape, size, arrangement, etc. of the configuration described in each drawing can be changed as appropriate.

Embodiment 1.
FIG. 1 is a refrigerant circuit diagram of a refrigeration cycle apparatus according to Embodiment 1. FIG. FIG. 2 is a schematic longitudinal sectional view showing a scroll compressor that is a component of the refrigeration cycle apparatus according to Embodiment 1. FIG. The refrigerating cycle device according to Embodiment 1 is used for applications such as air conditioners, refrigerating devices, refrigerators, freezers, vending machines, and water heaters, for example. The refrigeration cycle device includes a refrigerant circuit 100 having a main circuit A, a refrigerant injection circuit B, and an oil injection circuit C, as shown in FIG.

The main circuit A, as shown in FIGS. The exchanger 202, the decompression device 203, and the second heat exchanger 204 are connected in order by pipes to circulate the refrigerant.

Refrigerant injection circuit B is, as shown in FIGS. . The refrigerant injection circuit B is provided with a second control valve 207 that adjusts the flow rate of refrigerant flowing through the refrigerant injection circuit B, and a second electromagnetic valve 208 that opens and closes the refrigerant injection circuit B. FIG. The second control valve 207 is composed of, for example, an electronic expansion valve. The refrigerant circuit 100 may omit the second electromagnetic valve 208 as long as the second control valve 207 can adjust the degree of opening from 0% to 100%.

As shown in FIGS. 1 and 2, the oil injection circuit C is branched from the oil separator 201, connected to the second heat exchanger 204, and then connected to the refrigerant injection circuit B. It is the structure connected to the injection pipe 12 of the scroll compressor 200 via. The oil injection circuit C includes a first control valve 205 that adjusts the flow rate of oil flowing through the oil injection circuit C between the second heat exchanger 204 and the connection point of the refrigerant injection circuit B, and the oil injection circuit C. A first electromagnetic valve 206 that opens and closes is provided. The first control valve 205 is composed of, for example, an electronic expansion valve. The refrigerant circuit 100 may omit the first solenoid valve 206 if the first control valve 205 is configured to be able to adjust the degree of opening from 0% to 100%.

Next, each component constituting the refrigerant circuit 100 will be described. First, based on FIG. 2, the structure of the scroll compressor 200 is demonstrated.

The scroll compressor 200 sucks and compresses the refrigerant circulating in the refrigerant circuit 100, and discharges the refrigerant in a high-temperature, high-pressure state. As shown in FIG. 2, the scroll compressor 200 includes a shell 1 forming an outer shell, a main frame 2 fixed to the inner wall surface of the shell 1, a compression mechanism section 3 having a compression chamber 30 for compressing a refrigerant, A drive mechanism portion 6 that drives the compression mechanism portion 3 and a main shaft 7 that connects the compression mechanism portion 3 and the drive mechanism portion 6 are provided.

The shell 1 consists of a pressure vessel. The shell 1 is connected with a suction pipe 10 for taking refrigerant into the shell 1 from the outside and a discharge pipe 11 for discharging the compressed refrigerant from the shell 1 to the outside. The pressure of the refrigerant sucked from the suction pipe 10 is a low pressure Ps. The pressure of the refrigerant discharged from the discharge pipe 11 is high pressure Pd. An oil sump 14 for storing refrigerating machine oil is provided at the inner bottom of the shell 1 . Refrigerant oil is supplied to the compression mechanism portion 3 and each bearing through an oil supply passage 70 formed in the main shaft 7 .

The compression mechanism section 3 includes a fixed scroll 4 and an orbiting scroll 5 . The fixed scroll 4 is fixed by bolts or the like to the main frame 2 fixed to the inner wall surface of the shell 1 . The fixed scroll 4 has a fixed base plate 40 and a fixed spiral tooth 41 which is an involute curve-shaped protrusion provided on the lower surface of the fixed base plate 40 . The oscillating scroll 5 has an oscillating base plate 50 and an oscillating spiral tooth 51 that is an involute curve-shaped protrusion provided on the upper surface of the oscillating base plate 50 .

The fixed scroll 4 and the orbiting scroll 5 are arranged in the shell 1 in a symmetrical spiral shape in which the fixed spiral teeth 41 and the orbiting spiral teeth 51 are meshed in opposite phases with respect to the rotation center of the main shaft 7. . In the compression mechanism section 3, the fixed scroll 4 and the oscillating scroll 5 are combined so that the fixed spiral teeth 41 and the oscillating spiral teeth 51 are engaged with each other. A compression chamber 30 is formed. As the main shaft 7 rotates, the volume of the compression chamber 30 decreases from radially outward to radially inward.

A discharge port 42 is formed in the central portion of the fixed base plate 40 to discharge the high-temperature and high-pressure refrigerant compressed in the compression chamber 30 . A back plate 15 having a discharge passage 15a communicating with a discharge port 42 is provided on the upper surface of the fixed scroll 4 and fixed by bolting or the like. The back plate 15 is provided with a discharge valve 16 that opens and closes the discharge passage 15a according to the pressure of the refrigerant. The discharge valve 16 opens the discharge passage 15a when the refrigerant in the compression chamber 30 communicating with the discharge port 42 reaches a predetermined pressure. The compressed high-temperature and high-pressure refrigerant is discharged from the discharge port 42 into the discharge space 13 above the fixed scroll 4 , passes through the discharge pipe 11 , and is discharged to the outside of the shell 1 .

An injection passage 43 communicating with the compression chamber 30 is formed in the fixed base plate 40 . The injection flow path 43 is formed at a position where it communicates with the compression chamber 30 at the initial stage or intermediate stage of the compression stroke during one rotation of the main shaft 7 . The pressure in the compression chamber 30 at this time is an intermediate pressure between the low pressure Ps and the high pressure Pd. Further, the back plate 15 is formed with a communication channel 15 b that communicates with the injection channel 43 . An injection pipe 12 communicating with the communication passage 15b from the outside of the shell 1 is fixed to the back plate 15 by a connecting member 12a. That is, the injection channel 43 is connected to the injection pipe 12 via the communication channel 15b. Refrigerant and oil are supplied from the injection pipe 12 to the compression chamber 30 through the communication channel 15 b and the injection channel 43 .

The orbiting scroll 5 revolves around the fixed scroll 4 without rotating due to an Oldham's coupling 8 for preventing rotation. The surface of the rocking base plate 50 on which the rocking spiral teeth 51 are not formed acts as a rocking scroll thrust bearing surface. A hollow cylindrical boss portion 52 is provided at the center of the orbiting scroll thrust bearing surface. An eccentric shaft portion 71 provided at one end of the main shaft 7 is rotatably connected to the boss portion 52 . The orbiting scroll 5 revolves on the thrust sliding surface of the main frame 2 by rotating the eccentric shaft portion 71 of the main shaft 7 inserted into the boss portion 52 .

The drive mechanism section 6 is provided below the main frame 2 and rotates the orbiting scroll 5 connected via the main shaft 7 with respect to the fixed scroll 4 . The driving mechanism 6 is composed of an annular stator 60 fixed to the inner wall surface of the shell 1 by shrink fitting or the like, and a rotor 61 rotatably provided facing the inner surface of the stator 60. ing. The stator 60 has a structure in which a winding is wound around an iron core formed by laminating a plurality of electromagnetic steel sheets, for example, with an insulating layer interposed therebetween. The rotor 61 has a structure in which a permanent magnet is built in an iron core formed by laminating a plurality of electromagnetic steel sheets, and has a through hole penetrating vertically in the center. A main shaft 7 is fixed to the through hole of the rotor 61 . In the drive mechanism section 6, the rotor 61 rotates when the stator 60 is energized, and the main shaft 7 rotates with the rotation of the rotor 61. It is a configuration in which the driving force is transmitted.

Next, each component of the refrigerant circuit 100 other than the scroll compressor 200 will be described. The oil separator 201 is connected to the discharge side of the scroll compressor 200 and separates oil contained in refrigerant gas discharged from the scroll compressor 200 . The oil separated from the refrigerant gas by the oil separator 201 is returned to the suction side of the scroll compressor 200 via the oil injection circuit C. Oil that has not been separated by the oil separator 201 flows through the first heat exchanger 202 , the decompression device 203 and the second heat exchanger 204 in order, and is returned to the suction side of the scroll compressor 200 .

The first heat exchanger 202 in Embodiment 1 functions as a condenser. The first heat exchanger 202 exchanges heat between the refrigerant discharged from the scroll compressor 200 and a heat medium such as air or water to condense and liquefy the refrigerant. The first heat exchanger 202 has an inflow side connected to the oil separator 201 and an outflow side connected to the decompression device 203 .

The decompression device 203 decompresses and expands the supplied refrigerant. The decompression device 203 is composed of, for example, an expansion valve or a capillary tube.

The second heat exchanger 204 in Embodiment 1 functions as an evaporator. The second heat exchanger 204 exchanges heat between the air sucked from the intake port and the refrigerant. to evaporate the refrigerant. The second heat exchanger 204 has an inflow side connected to the pressure reducing device 203 and an outflow side connected to the scroll compressor 200 .

The control device 300 controls the entire refrigeration cycle device. The control device 300 controls, for example, the rotation speed of the scroll compressor 200, the opening control of the expansion valves that constitute the pressure reducing device 203, the control of the first control valve 205 and the second control valve 207, the control of the first solenoid valve 206 and the second Opening and closing operations of the electromagnetic valve 208 are performed. The control device 300 is composed of a microcomputer or the like, and includes a CPU, a RAM, a ROM, and the like.

Next, the refrigerant flow and injection operation of the refrigerant circuit 100 according to Embodiment 1 will be described. In the main circuit A, the refrigerant discharged from the scroll compressor 200 is separated into refrigerant and oil by the oil separator 201 and then cooled by the first heat exchanger 202 . The refrigerant cooled by the first heat exchanger 202 is decompressed by the decompression device 203 and then heated by the second heat exchanger 204 to become refrigerant gas. Refrigerant gas that has flowed out of the second heat exchanger 204 returns to the scroll compressor 200 .

Here, the control device 300 closes the first control valve 205 and the first solenoid valve 206 and opens the second control valve 207 and the second solenoid valve 208 during the refrigerant injection operation. As a result, the injection refrigerant, which is part of the high-pressure liquid refrigerant cooled by the first heat exchanger 202, flows into the refrigerant injection circuit B, is decompressed by the second control valve 207, and becomes a liquid state or a two-phase state. , flows into the injection pipe 12 of the scroll compressor 200 via the second solenoid valve 208 . The injection refrigerant that has flowed into the injection pipe 12 flows through the communication flow path 15b and the injection flow path 43 into the compression chamber 30 during compression. At this time, since the first control valve 205 and the first electromagnetic valve 206 of the oil injection circuit C are closed, oil does not flow through the injection pipe 12 .

Further, the control device 300 opens the first control valve 205 and the first solenoid valve 206 and closes the second control valve 207 and the second solenoid valve 208 during the oil injection operation. As a result, part of the oil discharged from the scroll compressor 200 and separated into refrigerant and oil by the oil separator 201 flows into the oil injection circuit C and is cooled by the second heat exchanger 204. After becoming oil, the pressure is reduced and the flow rate is adjusted by the second control valve 207 , connected to the piping of the refrigerant injection circuit B, and flows into the injection piping 12 of the scroll compressor 200 . The injection oil that has flowed into the injection pipe 12 passes through the communication flow path 15b and the injection flow path 43 and flows into the compression chamber 30 during the compression process. At this time, since the second control valve 207 and the second electromagnetic valve 208 of the refrigerant injection circuit B are closed, the refrigerant does not flow through the injection pipe 12 .

The internal pressure P of the compression chamber 30 when the injection passage 43 communicates with the compression chamber 30 during compression is lower than the internal pressure Pm in the refrigerant injection circuit B and the oil injection circuit C. This is because, as described above, the injection flow path 43 is formed at a position communicating with the compression chamber 30 at the initial or intermediate stage of the compression stroke during one rotation of the main shaft 7 . Due to the pressure difference between the internal pressure P of the compression chamber 30 and the internal pressure Pm of the refrigerant injection circuit B and the oil injection circuit C, the injection refrigerant or injection oil flows from the injection pipe 12 into the communication passage 15b and the injection passage 43. It flows in and is supplied to the compression chamber 30 . As a result, the gas refrigerant that is in the process of being compressed is cooled. In addition, oil is supplied into the compression chamber 30 to form an oil seal between the fixed spiral tooth 41 and the oscillating spiral tooth 51 .

As described above, the refrigeration cycle apparatus of Embodiment 1 includes a scroll compressor 200 having a compression chamber 30 for compressing a refrigerant and an injection pipe 12 connected to the compression chamber 30, an oil separator 201, a first A heat exchanger 202, a decompression device 203, and a second heat exchanger 204 are connected in order by pipes, a main circuit A in which refrigerant circulates, and an injection pipe of the scroll compressor 200 branched from the oil separator 201. 12, and a control device 300 that controls the operation of the refrigeration cycle device. The oil injection circuit C is provided with a first control valve 205 that is controlled by the control device 300 and adjusts the flow rate of oil flowing through the oil injection circuit C. As shown in FIG.

Therefore, in the refrigeration cycle apparatus of Embodiment 1, the oil injection circuit C is provided with the first control valve 205 for adjusting the flow rate of oil, so that the flow rate and timing of injection of oil into the compression chamber 30 can be controlled. . Therefore, in a state where the operating frequency of the scroll compressor 200 is in a high speed range, the amount of oil supplied to the compression chamber 30 can be adjusted. can be suppressed, and deterioration in performance due to an increase in the amount of discharged oil circulating can be suppressed.

The oil injection circuit C is branched from the oil separator 201 and connected to the injection pipe 12 of the scroll compressor 200 via the second heat exchanger 204 . Therefore, in the refrigeration cycle apparatus of Embodiment 1, the oil separated by the oil separator 201 can be cooled by the second heat exchanger 204 and then injected into the compression chamber 30. The refrigerant gas can be cooled, and the discharge temperature can be suppressed. In addition, by cooling the oil, it is possible to inject oil with high viscosity into the compression chamber 30, so that the sealing performance between the tooth tips of the fixed spiral tooth 41 and the oscillating spiral tooth 51 is improved, resulting in refrigerant leakage loss. can be reduced and the performance can be improved.

The refrigeration cycle apparatus of Embodiment 1 further includes a refrigerant injection circuit B branched from the pipe between the first heat exchanger 202 and the pressure reducing device 203 and connected to the injection pipe 12 of the scroll compressor 200. ing. Refrigerant injection circuit B is provided with a second control valve 207 that is controlled by control device 300 to control the flow rate of the refrigerant flowing through refrigerant injection circuit B. As shown in FIG. Therefore, the refrigeration cycle apparatus of Embodiment 1 can adjust the flow rate and timing of the refrigerant injected into the compression chambers 30, so that an appropriate amount of refrigerant can be injected into the compression chambers 30. can be expanded and the frequency range to be used can be expanded.

Further, the control device 300 performs control to close the first control valve 205 and open the second control valve 207 during the refrigerant injection operation, and to open the first control valve 205 and open the second control valve 207 during the oil injection operation. Control is performed to close the control valve 207 . Therefore, in the refrigeration cycle apparatus of Embodiment 1, the oil injection circuit C is closed during high-speed operation of the compressor, thereby suppressing the circulation amount of the discharged oil and improving the performance. By injecting oil from time to time, it becomes possible to supply oil between the fixed spiral tooth 41 and the oscillating spiral tooth 51, thereby preventing wear of the fixed spiral tooth 41 and the oscillating spiral tooth 51 and improving reliability. be able to.

Embodiment 2.
Next, a refrigeration cycle apparatus according to Embodiment 2 will be described with reference to FIG. FIG. 3 is a refrigerant circuit diagram of a refrigeration cycle apparatus according to Embodiment 2. FIG. The same reference numerals are given to the same configurations as those of the refrigeration cycle apparatus described in Embodiment 1, and the description thereof will be omitted as appropriate.

The refrigeration cycle apparatus according to Embodiment 2 includes a refrigerant circuit 101 having a main circuit A, a refrigerant injection circuit B, and an oil injection circuit C, as shown in FIG.

The main circuit A has a structure in which a scroll compressor 200, an oil separator 201, a first heat exchanger 202, a pressure reducing device 203, and a second heat exchanger 204 are connected in order by pipes, and the refrigerant circulates. is. The first heat exchanger 202 in Embodiment 2 functions as a condenser. Also, the second heat exchanger 204 in the second embodiment functions as an evaporator.

Refrigerant injection circuit B is configured to be branched from a pipe between first heat exchanger 202 and decompression device 203 and connected to injection pipe 12 of scroll compressor 200 . The refrigerant injection circuit B is provided with a second control valve 207 that adjusts the flow rate of oil flowing through the oil injection circuit C. As shown in FIG. The second control valve 207 is configured so that the degree of opening can be adjusted from 0% to 100%. In addition, as shown in Embodiment 1, the refrigerant injection circuit B may be provided with the second solenoid valve 208 for opening and closing the refrigerant injection circuit B. FIG.

The oil injection circuit C branches from the oil separator 201 and is connected between the second control valve 207 and the scroll compressor 200 in the refrigerant injection circuit B. Through the refrigerant injection circuit B, the scroll compressor 200 is injected. It is configured to be connected to the pipe 12 . The oil injection circuit C is provided with a first control valve 205 that adjusts the flow rate of oil flowing through the oil injection circuit C. As shown in FIG. The first control valve 205 is configured so that the degree of opening can be adjusted from 0% to 100%. Note that, as shown in Embodiment 1, the oil injection circuit C may be provided with the first solenoid valve 206 for opening and closing the oil injection circuit C.

As described above, in the refrigeration cycle apparatus of Embodiment 2, the oil injection circuit C is provided with the first control valve 205 for adjusting the flow rate of oil. can be controlled. Therefore, in a state where the operating frequency of the scroll compressor 200 is in a high speed range, the amount of oil supplied to the compression chamber 30 can be adjusted. can be suppressed, and deterioration in performance due to an increase in the amount of discharged oil circulating can be suppressed.

In addition, since the refrigeration cycle apparatus of Embodiment 2 can adjust the flow rate and timing of the refrigerant injected into the compression chamber 30, an appropriate amount of refrigerant can be injected into the compression chamber 30. can be expanded and the frequency range to be used can be expanded.

Further, in the refrigeration cycle apparatus of Embodiment 2, the oil injection circuit C is closed during high-speed operation of the compressor, so that the amount of discharged oil circulated can be suppressed and the performance can be improved. By injecting oil from time to time, it becomes possible to supply oil between the fixed spiral tooth 41 and the oscillating spiral tooth 51, thereby preventing wear of the fixed spiral tooth 41 and the oscillating spiral tooth 51 and improving reliability. be able to.

Embodiment 3.
Next, a refrigeration cycle apparatus according to Embodiment 3 will be described with reference to FIG. 4 is a refrigerant circuit diagram of a refrigeration cycle apparatus according to Embodiment 3. FIG. The same reference numerals are given to the same configurations as those of the refrigeration cycle apparatuses described in Embodiments 1 and 2, and the description thereof will be omitted as appropriate.

Refrigerant circuit 102 of a refrigeration cycle apparatus according to Embodiment 3 has, in addition to the configuration of Embodiment 2, an oil return pipe 209 that bypasses oil separator 201 and the suction side of scroll compressor 200. Characterized by The oil return pipe 209 is provided with a third control valve 210 that is controlled by the control device 300 and adjusts the flow rate of oil flowing through the oil return pipe 209 . The third control valve 210 is composed of an electronic expansion valve or the like capable of adjusting the degree of opening from 0% to 100%. A solenoid valve for opening and closing the oil return pipe 209 may be provided in the oil return pipe 209 .

Scroll compressor 200 has a sufficient amount of oil supplied to compression mechanism 3 during high-speed operation. Therefore, the amount of oil supplied to the injection flow path 43 is made zero or extremely small. However, if scroll compressor 200 continues to operate at high speed, oil may accumulate in oil separator 201 and oil in scroll compressor 200 may be depleted. Therefore, it is preferable to provide an oil return pipe 209 that bypasses the suction side of the oil separator 201 and the scroll compressor 200 as in the refrigeration cycle apparatus of the third embodiment. Furthermore, a third control valve 210 may be provided in the oil return pipe 209 to return oil to the suction side of the scroll compressor 200 according to the amount of oil in the oil separator 201 . The amount of oil in the oil separator 201 is obtained from the measured value of the amount of oil by an oil gauge. Note that the amount of oil in the oil separator 201 may be obtained from the operating frequency of the scroll compressor 200 and its operating time. Also, the amount of oil in the oil separator 201 may be obtained by an estimated value calculated from the amount of oil returned to the scroll compressor 200 through the oil return pipe 209 .

Embodiment 4.
Next, a refrigeration cycle apparatus according to Embodiment 4 will be described with reference to FIG. FIG. 5 is a refrigerant circuit diagram of a refrigeration cycle apparatus according to Embodiment 4. FIG. The same reference numerals are assigned to the same configurations as those of the refrigeration cycle apparatus described in the first to third embodiments, and the description thereof will be omitted as appropriate.

A refrigeration cycle apparatus according to Embodiment 4 is, for example, an air conditioner capable of cooling and heating. This refrigeration cycle apparatus includes a refrigerant circuit 103 having a main circuit A, a refrigerant injection circuit B, and an oil injection circuit C, as shown in FIG.

The main circuit A includes a scroll compressor 200, an oil separator 201, a flow path switching means 211, a first heat exchanger 202, a first pressure reducing device 212, a second pressure reducing device 213, and a second heat exchanger. 204 and are connected in order by pipes, and the refrigerant circulates.

The channel switching means 211 is, for example, a four-way valve, and has a function of switching the coolant channel under control of the control device 300 . During cooling operation, the flow path switching means 211 connects the discharge side of the scroll compressor 200 and the first heat exchanger 202, and connects the suction side of the scroll compressor 200 and the first heat exchanger 202, as indicated by the solid line in FIG. 2 switch the refrigerant flow path so as to connect with the heat exchanger 204 . During heating operation, the flow path switching means 211 connects the discharge side of the scroll compressor 200 and the second heat exchanger 204, and connects the suction side of the scroll compressor 200 and the second heat exchanger 204, as indicated by the dashed line in FIG. 1 switch the refrigerant flow path so as to connect with the heat exchanger 202 . The channel switching means 211 may be configured by combining two-way valves or three-way valves.

The first heat exchanger 202 functions as a condenser to liquefy the refrigerant during cooling operation, and functions as an evaporator to evaporate the refrigerant during heating operation. The second heat exchanger 204 functions as an evaporator during cooling operation, and functions as a condenser during heating operation.

The first decompression device 212 and the second decompression device 213 are controlled by the control device 300 to decompress and expand the supplied refrigerant. The first decompression device 212 and the second decompression device 213 are configured by, for example, expansion valves or capillary tubes.

Refrigerant injection circuit B is configured to branch from a pipe between first pressure reducing device 212 and second pressure reducing device 213 and to be connected to injection pipe 12 of scroll compressor 200 . The refrigerant injection circuit B is provided with a second control valve 207 that adjusts the flow rate of the refrigerant flowing through the refrigerant injection circuit B. As shown in FIG. The second control valve 207 is configured so that the degree of opening can be adjusted from 0% to 100%. In addition, as shown in Embodiment 1, the refrigerant injection circuit B may be provided with the second solenoid valve 208 for opening and closing the refrigerant injection circuit B. FIG.

The oil injection circuit C branches from the oil separator 201 and is connected between the second control valve 207 and the scroll compressor 200 in the refrigerant injection circuit B. Through the refrigerant injection circuit B, the scroll compressor 200 is injected. It is configured to be connected to the pipe 12 . The oil injection circuit C is provided with a first control valve 205 that adjusts the flow rate of oil flowing through the oil injection circuit C. As shown in FIG. The first control valve 205 is configured so that the degree of opening can be adjusted from 0% to 100%. Note that, as shown in Embodiment 1, the oil injection circuit C and the first electromagnetic valve 206 for opening and closing the oil injection circuit C may be provided.

Refrigerant circuit 103 in Embodiment 4 is provided with oil return pipe 209 that bypasses oil separator 201 and the suction side of scroll compressor 200 . The oil return pipe 209 is provided with a third control valve 210 that is controlled by the control device 300 and adjusts the flow rate of oil flowing through the oil return pipe 209 . The third control valve 210 is composed of an electronic expansion valve or the like capable of adjusting the degree of opening from 0% to 100%. Although not shown, the oil return pipe 209 may be provided with an electromagnetic valve for opening and closing the oil return pipe 209 .

As described above, also in the refrigeration cycle apparatus according to the fourth embodiment, the same effects as those described in the second and third embodiments can be obtained.

Embodiment 5.
Next, a refrigeration cycle apparatus according to Embodiment 5 will be described with reference to FIG. 6 is a refrigerant circuit diagram of a refrigeration cycle apparatus according to Embodiment 5. FIG. The same reference numerals are assigned to the same configurations as those of the refrigeration cycle apparatus described in the first to fourth embodiments, and the description thereof will be omitted as appropriate.

As shown in FIG. 6, the refrigerating cycle device according to Embodiment 5 differs from the refrigerating cycle device according to Embodiment 4 described above in the configuration of the oil injection circuit C. As shown in FIG. Therefore, in the fifth embodiment, only the configuration of the oil injection circuit C will be described, and the configuration of the fourth embodiment is used for other configurations.

The oil injection circuit C in Embodiment 5 has a first oil injection circuit C1 and a second oil injection circuit C2.

As shown in FIG. 6, the first oil injection circuit C1 is branched from the oil separator 201, connected to the first heat exchanger 202, and then connected to the refrigerant injection circuit B. , and connected to the injection pipe 12 of the scroll compressor 200 shown in FIG. Between the oil separator 201 and the first heat exchanger 202 in the first oil injection circuit C1, a first control valve 205 that is controlled by the control device 300 and adjusts the flow rate of oil flowing through the first oil injection circuit C1. is provided. The first control valve 205 is composed of an electronic expansion valve or the like capable of adjusting the degree of opening from 0% to 100%. A solenoid valve for opening and closing the first oil injection circuit C1 may be provided in the first oil injection circuit C1.

As shown in FIG. 6, the second oil injection circuit C2 is branched from the oil separator 201, connected to the second heat exchanger 204, and then connected to the refrigerant injection circuit B. , and connected to the injection pipe 12 of the scroll compressor 200 shown in FIG. Between the oil separator 201 and the second heat exchanger 204 in the second oil injection circuit C2, a first control valve 205 that is controlled by the control device 300 and adjusts the flow rate of oil flowing through the second oil injection circuit C2. is provided. The first control valve 205 is composed of an electronic expansion valve or the like capable of adjusting the degree of opening from 0% to 100%. A solenoid valve for opening and closing the second oil injection circuit C2 may be provided in the second oil injection circuit C2.

In the refrigerant circuit 104 of Embodiment 5, when the first heat exchanger 202 functions as an evaporator, oil is supplied from the injection pipe 12 to the compression chamber 30 through the first oil injection circuit C1, and the second heat exchanger When 204 functions as an evaporator, oil is supplied from the injection pipe 12 to the compression chamber 30 through the second oil injection circuit C2.

As described above, also in the refrigeration cycle apparatus according to the fifth embodiment, it is possible to obtain the same effects as those described in the first embodiment.

Although the refrigeration cycle apparatus has been described above based on the embodiment, the refrigeration cycle apparatus is not limited to the configuration of the embodiment described above. The refrigeration cycle device is not limited to the components described above, and may include other components or omit some components. For example, the coolant injection circuit B is not necessarily provided and may be omitted. Also, the oil separator 201 may be provided between the condenser and the decompression device, or between the decompression device and the branch point of the refrigerant injection circuit B. In this case, the temperature of the oil can also be lowered as the temperature of the refrigerant is lowered by the refrigeration cycle. Moreover, the magnitude of the pressure is not determined by the relationship with the absolute value, but relatively determined by the state and operation of the system and device. In short, the refrigeration cycle apparatus includes a range of design changes and application variations that are normally made by those skilled in the art within a range that does not deviate from the technical idea thereof.

Reference Signs List 1 Shell 2 Main Frame 3 Compression Mechanism Part 4 Fixed Scroll 5 Oscillating Scroll 6 Drive Mechanism Part 7 Main Shaft 8 Oldham Coupling 10 Suction Pipe 11 Discharge Pipe 12 Injection Pipe 12a Connection Member 13 Discharge space 14 Oil reservoir 15 Back plate 15a Discharge channel 15b Communication channel 16 Discharge valve 30 Compression chamber 40 Fixed base plate 41 Fixed spiral tooth 42 Discharge port 43 Injection channel 50 Fluctuation 100, 101, 102, 103 Refrigerant circuit 200
scroll compressor 201 oil separator 202 first heat exchanger 203 decompression device 204 second heat exchanger 205 first control valve 206 first solenoid valve 207 second control valve 208 second solenoid valve , 209 oil return pipe, 210 third control valve, 211 flow path switching means, 212 first pressure reducing device, 213 second pressure reducing device, 300 control device, A main circuit, B refrigerant injection circuit, C oil injection circuit, C1 first first Oil injection circuit, second oil injection circuit.

Claims (4)

A scroll compressor having a compression chamber for compressing a refrigerant and an injection pipe connected to the compression chamber, an oil separator, a first heat exchanger, a decompression device, and a second heat exchanger are connected in order by pipes. a main circuit connected and through which a refrigerant circulates;
an oil injection circuit branched from the oil separator and connected to the injection pipe of the scroll compressor;
and a control device that controls the operation of the refrigeration cycle device,
The oil injection circuit is
a first oil injection circuit branched from the oil separator and connected to the injection pipe of the scroll compressor via the first heat exchanger;
a second oil injection circuit branched from the oil separator and connected to the injection pipe of the scroll compressor via the second heat exchanger;
The first oil injection circuit and the second oil injection circuit are each provided with a first control valve that is controlled by the control device and adjusts the flow rate of oil flowing through the oil injection circuit,
The control device closes the first control valve during high-speed operation of the scroll compressor and opens the first control valve during low-speed operation of the scroll compressor to perform oil injection. Device. further comprising a refrigerant injection circuit branched from a pipe between the first heat exchanger and the decompression device and connected to the injection pipe of the scroll compressor,
2. The refrigeration cycle apparatus according to claim 1 , wherein said refrigerant injection circuit is provided with a second control valve that is controlled by said controller and adjusts the flow rate of refrigerant flowing through said refrigerant injection circuit. The control device is
performing control to close the first control valve and open the second control valve during the refrigerant injection operation;
3. The refrigeration cycle apparatus according to claim 2 , wherein control is performed to open said first control valve and to close said second control valve during an oil injection operation. further comprising an oil return pipe connecting the oil separator and the suction side of the scroll compressor,
The refrigeration cycle apparatus according to any one of claims 1 to 3 , wherein the oil return pipe is provided with a third control valve that is controlled by the control device and adjusts the flow rate of oil flowing through the oil return pipe. .

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