Refrigeration cycle device

Abstract

In a refrigeration cycle device, a compression mechanism unit includes a cylinder, a piston disposed in the cylinder, and a vane that partitions an inside of the cylinder. A shaft includes an eccentric portion. In the refrigeration cycle device, a vane groove in which the vane is disposed is formed in the cylinder. The eccentric portion is disposed in the cylinder. The piston is fitted to the eccentric portion. The vane operates without being separated from the piston. In the refrigeration cycle device, a receiver that stores a part of a refrigerant flowing through the refrigerant pipe is provided in the refrigerant pipe, and a receiver internal volume of the receiver is made larger than a difference between a utilization-side internal volume of heat exchange of the utilization-side heat exchanger and a heat source-side internal volume of heat exchange of the heat source-side heat exchanger to reduce a liquid refrigerant sucked into the cylinder.

Description

BACKGROUND1. Technical Field

[0001] The present disclosure relates to a refrigeration cycle device using a compressor in which a vane operates without moving away from a piston.2. Description of the Related Art

[0002] The rotary compressor disclosed in PTL 1 has a configuration in which a piston and a vane that partitions a compression chamber and a suction chamber in a cylinder are integrally provided. A protruding-side distal end portion of the vane is received in a receiving groove of a rotatably supportive columnar support, and the receiving groove penetrates from one side to the other side of an outer peripheral surface. Therefore, since the piston and the vane do not repeat separation and contact, refrigeration oil does not deteriorate or hydrolyze, sludge is not generated and does not adhere to the inside of a refrigeration cycle, and a highly reliable refrigeration cycle device can be provided.Citation ListPatent Literature

[0003] PTL 1: Unexamined Japanese Patent Publication No. H08-121364SUMMARY

[0004] However, since the piston and the vane are integrally configured, when a liquid refrigerant is supplied to the compressor, the refrigerant does not leak from a high pressure side to a low pressure side in the compression chamber, and thus liquid compression occurs. Therefore, a large load is applied to the vane, and the vane or a component constituting the compressor may be damaged. Furthermore, even in the case of the low rotation operation of the compressor, since the refrigerant cannot be released from the high pressure side to the low pressure side, the compression load does not decrease, and the rotation operation may become unstable.

[0005] Therefore, the present disclosure provides a refrigeration cycle device capable of suppressing leakage of a refrigerant from a high pressure side to a low pressure side of a compression chamber and suppressing liquid compression.

[0006] A refrigeration cycle device according to one aspect of the present disclosure is a refrigeration cycle device in which a compressor, a utilization-side heat exchanger, a decompressor, a heat source-side heat exchanger, and a four-way valve are annularly connected by a refrigerant pipe. The compressor includes, in a sealed container, an electric motor unit and a compression mechanism unit. The electric motor unit and the compression mechanism unit are coupled by a shaft. The compression mechanism unit includes a cylinder, a piston disposed in the cylinder, and a vane that partitions an inside of the cylinder. The shaft includes an eccentric portion. A vane groove in which the vane is disposed is formed in the cylinder. The eccentric portion is disposed in the cylinder. The piston is fitted to the eccentric portion. The vane operates without being separated from the piston. In the refrigeration cycle device, a receiver that stores a part of a refrigerant flowing through the refrigerant pipe is provided in the refrigerant pipe, and a receiver internal volume of the receiver is made larger than a difference between a utilization-side internal volume of heat exchange of the utilization-side heat exchanger and a heat source-side internal volume of heat exchange of the heat source-side heat exchanger to reduce a liquid refrigerant sucked into the cylinder.

[0007] According to the present disclosure, leakage of a refrigerant from a high pressure side to a low pressure side of a compression chamber can be prevented, and liquid compression can be suppressed.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Fig. 1 is a configuration diagram illustrating a refrigeration cycle device according to an example of the present disclosure; Fig. 2 is a sectional view illustrating a compressor used in the refrigeration cycle device according to the present example; Fig. 3A is an A-A arrow view of the compressor illustrated in Fig. 2; Fig. 3B is a perspective view of the compressor illustrated in Fig. 2 in a state where a piston and a vane are separated from each other; Fig. 4 is a flowchart illustrating refrigerant flow channel switching control of the refrigeration cycle device according to the present example; Fig. 5A is an explanatory diagram illustrating control of a degree of superheating or a high and low pressure difference of the refrigeration cycle device according to the present example; and Fig. 5B is a diagram illustrating a relationship between a rotation speed band of the compressor, and a target degree of superheating and a target high and low pressure difference range in the refrigeration cycle device according to the present example. DETAILED DESCRIPTIONS

[0009] A refrigeration cycle device according to a first exemplary embodiment of the present disclosure is a refrigeration cycle device in which a compressor, a utilization-side heat exchanger, a decompressor, a heat source-side heat exchanger, and a four-way valve are annularly connected by a refrigerant pipe. The compressor includes, in a sealed container, an electric motor unit and a compression mechanism unit. The electric motor unit and the compression mechanism unit are coupled by a shaft. The compression mechanism unit includes a cylinder, a piston disposed in the cylinder, and a vane that partitions an inside of the cylinder. The shaft includes an eccentric portion. A vane groove in which the vane is disposed is formed in the cylinder. The eccentric portion is disposed in the cylinder. The piston is fitted to the eccentric portion. The vane operates without being separated from the piston. In the refrigeration cycle device according to the present exemplary embodiment, a receiver that stores a part of a refrigerant flowing through the refrigerant pipe is provided in the refrigerant pipe, and a receiver internal volume of the receiver is made larger than a difference between a utilization-side internal volume of heat exchange of the utilization-side heat exchanger and a heat source-side internal volume of heat exchange of the heat source-side heat exchanger to reduce a liquid refrigerant sucked into the cylinder. According to the present exemplary embodiment, the vane operates without being separated from the piston. Therefore, leakage of a refrigerant from a high pressure side to a low pressure side of a compression chamber can be prevented. Furthermore, according to the present exemplary embodiment, the receiver that stores a part of a refrigerant flowing through the refrigerant pipe is provided in the refrigerant pipe, so that the refrigerant can be stored in the receiver in a case where the refrigerant is excessive. Therefore, for example, even at the time of low external air temperature or at the time of starting the operation of the compressor, the degree of superheating of the refrigerant sucked into the compressor can be sufficiently secured, the vane can be suppressed from being damaged by a load due to liquid compression, and a decrease in reliability of the compressor due to liquid compression can be suppressed.

[0010] In a refrigeration cycle device according to a second exemplary embodiment of the present disclosure, in the refrigeration cycle device according to the first exemplary embodiment, the receiver includes a sealed container. Furthermore, in the refrigeration cycle device according to the present exemplary embodiment, a refrigerant introduction pipe that introduces the refrigerant into the receiver and a refrigerant derivation pipe that derives the refrigerant from the receiver are inserted vertically upward from a lower side of the container. According to the present exemplary embodiment, by inserting the refrigerant introduction pipe and the refrigerant derivation pipe vertically upward from the lower side of the container, the liquid refrigerant in the container does not flow out of the refrigerant derivation pipe due to inertia. Therefore, the inflow of the liquid refrigerant into the compressor can be suppressed, and the decrease in reliability of the compressor due to liquid return can be suppressed.

[0011] In a refrigeration cycle device according to a third exemplary embodiment of the present disclosure, in the refrigeration cycle device according to the first exemplary embodiment, the receiver is provided in the refrigerant pipe between the utilization-side heat exchanger and the decompressor, and the heat source-side internal volume of heat exchange is made larger than the utilization-side internal volume of heat exchange. In a case where the utilization-side heat exchanger operates as a condenser, if the utilization-side internal volume of heat exchange is smaller than the heat source-side internal volume of heat exchange, a refrigerant circulation amount becomes excessive. However, according to the present exemplary embodiment, by providing the receiver in the refrigerant pipe between the utilization-side heat exchanger and the decompressor, the liquid refrigerant can be stored in the receiver, the degree of superheating of the refrigerant sucked into the compressor can be more reliably secured, and a decrease in reliability of the compressor due to liquid return can be suppressed.

[0012] In a refrigeration cycle device according to a fourth exemplary embodiment of the present disclosure, in the refrigeration cycle device according to the third exemplary embodiment, the receiver includes a sealed container. Furthermore, in the refrigeration cycle device according to the present exemplary embodiment, a utilization heat exchange-side connection refrigerant pipe connected to the utilization-side heat exchanger and a decompressor-side connection refrigerant pipe connected to the decompressor are inserted vertically upward from a lower side of the container. Furthermore, in the refrigeration cycle device according to the present exemplary embodiment, an opening end portion of the decompressor-side connection refrigerant pipe is located higher than an opening end portion of the utilization heat exchange-side connection refrigerant pipe. As described above, in the refrigeration cycle device according to the present exemplary embodiment, the utilization heat exchange-side connection refrigerant pipe and the decompressor-side connection refrigerant pipe are inserted vertically upward from the lower side of the container, and further, the opening end portion of the decompressor-side connection refrigerant pipe is located higher than the opening end portion of the utilization heat exchange-side connection refrigerant pipe. As a result, the liquid refrigerant supplied from the utilization-side heat exchanger does not directly flow out to the decompressor, the degree of superheating of the refrigerant sucked into the compressor can be more reliably secured, and a decrease in reliability of the compressor due to liquid return can be suppressed.

[0013] In a refrigeration cycle device according to a fifth exemplary embodiment of the present disclosure, in the refrigeration cycle device according to the first exemplary embodiment, the receiver is provided in the refrigerant pipe between the heat source-side heat exchanger and the decompressor, and the utilization-side internal volume of heat exchange is made larger than the heat source-side internal volume of heat exchange. In a case where the heat source-side heat exchanger operates as a condenser, if the heat source-side internal volume of heat exchange is smaller than the utilization-side internal volume of heat exchange, a refrigerant circulation amount becomes excessive. However, according to the present exemplary embodiment, by providing the receiver in the refrigerant pipe between the heat source-side heat exchanger and the decompressor, the liquid refrigerant can be stored in the receiver, the degree of superheating of the refrigerant sucked into the compressor can be more reliably secured, and a decrease in reliability of the compressor due to liquid return can be suppressed.

[0014] In a refrigeration cycle device according to a sixth exemplary embodiment of the present disclosure, in the refrigeration cycle device according to the fifth exemplary embodiment, the receiver includes a sealed container. Furthermore, in the present refrigeration cycle device, a heat source heat exchange-side connection refrigerant pipe connected to the heat source-side heat exchanger and a decompressor-side connection refrigerant pipe connected to the decompressor are inserted vertically upward from a lower side of the container. Furthermore, in the present refrigeration cycle device, an opening end portion of the decompressor-side connection refrigerant pipe is located higher than an opening end portion of the heat source heat exchange-side connection refrigerant pipe. As described above, in the refrigeration cycle device according to the present exemplary embodiment, the heat source heat exchange-side connection refrigerant pipe and the decompressor-side connection refrigerant pipe are inserted vertically upward from the lower side of the container, and further, the opening end portion of the decompressor-side connection refrigerant pipe is located higher than the opening end portion of the heat source heat exchange-side connection refrigerant pipe. As a result, the liquid refrigerant supplied from the heat source-side heat exchanger does not directly flow out to the decompressor, the degree of superheating of the refrigerant sucked into the compressor can be more reliably ensured, and a decrease in reliability of the compressor due to liquid return can be suppressed.[Examples]

[0015] Hereinafter, examples of the present disclosure will be described in detail with reference to the drawings. However, the drawings described in the following examples are schematic views, and the ratio of the size and the thickness of each component does not necessarily reflect the actual dimension ratio. Furthermore, the configurations described in the following examples are merely examples of the present disclosure. The present disclosure is not limited to the following examples, and various modifications can be made according to the design and the like as long as the effects of the present disclosure can be achieved. Note that "vertically upward" in the following examples means that it is intended to be vertically upward, but includes a portion slightly deviated from vertically upward due to an error or the like. Specifically, vertically upward means within 90° ± 5°, preferably within 90° ± 3°, and more preferably within 90° ± 1°.

[0016] Fig. 1 is a configuration diagram illustrating refrigeration cycle device 100 according to an example of the present disclosure.

[0017] In refrigeration cycle device 100 according to the present example, compressor 1, utilization-side heat exchanger 2, decompressor 3, and heat source-side heat exchanger 4 are annularly connected by refrigerant pipe 5.

[0018] In refrigeration cycle device 100, refrigerant pipe 5 is provided with receiver 6 that stores a part of the refrigerant flowing through refrigerant pipe 5.

[0019] Receiver 6 is preferably provided in refrigerant pipe 5 between utilization-side heat exchanger 2 and decompressor 3. Receiver 6 is a sealed container, and a receiver internal volume of receiver 6 is made larger than a difference between a utilization-side internal volume of heat exchange of utilization-side heat exchanger 2 and a heat source-side internal volume of heat exchange of heat source-side heat exchanger 4.

[0020] In refrigeration cycle device 100, four-way valve 7 is provided in refrigerant pipe 5. That is, in refrigeration cycle device 100, compressor 1, utilization-side heat exchanger 2, decompressor 3, heat source-side heat exchanger 4, and four-way valve 7 may be annularly connected by refrigerant pipe 5.

[0021] Four-way valve 7 switches the refrigerant discharged from compressor 1 to flow to utilization-side heat exchanger 2 or heat source-side heat exchanger 4.

[0022] In a case where four-way valve 7 causes the refrigerant discharged from compressor 1 to flow into utilization-side heat exchanger 2, the refrigerant discharged from compressor 1 flows through utilization-side heat exchanger 2, decompressor 3, and heat source-side heat exchanger 4, and then returns to compressor 1 by four-way valve 7.

[0023] In a case where four-way valve 7 causes the refrigerant discharged from compressor 1 to flow into heat source-side heat exchanger 4, the refrigerant discharged from compressor 1 flows through heat source-side heat exchanger 4, decompressor 3, and utilization-side heat exchanger 2, and then returns to compressor 1 by four-way valve 7.

[0024] Refrigerant pipe 5 includes refrigerant discharge pipe 5a, first refrigerant pipe 5b, second refrigerant pipe 5c1, third refrigerant pipe 5c2, fourth refrigerant pipe 5d, fifth refrigerant pipe 5e, and refrigerant suction pipe 5f. Refrigerant discharge pipe 5a connects discharge pipe 13 (see Fig. 2) of compressor 1 and four-way valve 7. First refrigerant pipe 5b connects four-way valve 7 and utilization-side heat exchanger 2. Second refrigerant pipe 5c1 connects utilization-side heat exchanger 2 and receiver 6. Third refrigerant pipe 5c2 connects receiver 6 and decompressor 3. Fourth refrigerant pipe 5d connects decompressor 3 and heat source-side heat exchanger 4. Fifth refrigerant pipe 5e connects heat source-side heat exchanger 4 and four-way valve 7. Refrigerant suction pipe 5f connects four-way valve 7 and suction pipe 12 (see Fig. 2) of compressor 1.

[0025] Accumulator 14 is provided in refrigerant suction pipe 5f. Furthermore, refrigerant flow channel switching valve 8 is provided in refrigerant pipe 5 (refrigerant suction pipe 5f) located upstream of suction pipe 12 of compressor 1.

[0026] Refrigeration cycle device 100 includes heat storage tank 60 using compressor 1 as a heat source.

[0027] Heat storage tank 60 is provided around compressor 1 so as to surround compressor 1, and absorbs heat generated from compressor 1. Heat storage tank 60 includes, for example, a heat storage material such as an ethylene glycol aqueous solution, and stores the heat of sealed container 10 (see Fig. 2) of compressor 1 in the heat storage material. Then, the heat of the stored heat storage material is applied to heat exchange circuit 61. Heat storage tank 60 preferably includes a heat generating source such as a heater in addition to compressor 1 as a heat source.

[0028] Heat exchange circuit 61 includes an inner pipe through which a refrigerant passes, and in particular, the inner pipe that exchanges heat with the heat storage material in heat storage tank 60 preferably has grooves or irregularities formed on at least one of an inner surface and an outer surface of the inner pipe. By forming the grooves or irregularities on the inner surface and the outer surface of the inner pipe, the heat transfer coefficient can be improved, and heat exchange from heat storage tank 60 to the refrigerant flowing through the inner pipe can be promoted.

[0029] Refrigerant flow channel switching valve 8 switches between heat exchange circuit 61 that performs heat exchange in heat storage tank 60 and guides the refrigerant to suction pipe 12, and refrigerant suction pipe 5f that guides the refrigerant to suction pipe 12 without passing through heat exchange circuit 61.

[0030] Refrigeration cycle device 100 includes detector 70, which is any one of detector 70a, detector 70b, detector 70c, detector 70d, detector 70e, and detector 70f. Detector 70a detects the temperature or pressure of the refrigerant flowing through refrigerant discharge pipe 5a. Detector 70b detects the temperature or pressure of the refrigerant flowing through first refrigerant pipe 5b. Detector 70c detects the temperature or pressure of the refrigerant flowing through second refrigerant pipe 5c1 or third refrigerant pipe 5c2. Detector 70d detects the temperature or pressure of the refrigerant flowing through fourth refrigerant pipe 5d. Detector 70e detects the temperature or pressure of the refrigerant flowing through fifth refrigerant pipe 5e. Detector 70f detects the temperature or pressure of the refrigerant flowing through refrigerant suction pipe 5f.

[0031] Refrigeration cycle device 100 includes controller 80 that controls a rotation speed of compressor 1 and a throttle amount of decompressor 3 to adjust a refrigerant circulation amount. Controller 80 controls the rotation speed (frequency) of compressor 1, an opening degree of decompressor 3, switching of four-way valve 7, and switching of refrigerant flow channel switching valve 8 on the basis of a detection value from detector 70 and instruction data from an input unit. Note that controller 80 may be a hardware circuit designed exclusively for realizing the control of refrigeration cycle device 100. Furthermore, controller 80 may realize the control of refrigeration cycle device 100 by a processor executing a program stored in a memory, that is, by the cooperation of hardware and software. Although the program to be executed by the processor is here to be recorded in advance in the memory, the control program may be provided by being recorded in a non-temporary recording medium such as a memory card, or may be provided through a telecommunication line such as the Internet.

[0032] End portions of second refrigerant pipe 5c1 and third refrigerant pipe 5c2 are inserted into receiver 6 from a lower portion of receiver 6.

[0033] In refrigeration cycle device 100, a refrigerant introduction pipe that introduces a refrigerant into receiver 6 and a refrigerant derivation pipe that derives the refrigerant from receiver 6 are inserted into receiver 6 that is a sealed container in a vertically upward direction from a lower side of the container. As described above, by inserting the refrigerant introduction pipe and the refrigerant derivation pipe vertically upward from the lower side of the container, liquid refrigerant in the container does not flow out of the refrigerant derivation pipe due to inertia. Therefore, the inflow of the liquid refrigerant into compressor 1 can be suppressed, and the decrease in reliability of compressor 1 due to liquid return can be suppressed.

[0034] When the operation mode is a heating operation mode and a forward cycle defrosting operation mode, second refrigerant pipe 5c1 serves as a refrigerant introduction pipe, and third refrigerant pipe 5c2 serves as a refrigerant derivation pipe.

[0035] Furthermore, when the operation mode is a cooling operation mode and a reverse cycle defrosting operation mode, third refrigerant pipe 5c2 serves as a refrigerant introduction pipe, and second refrigerant pipe 5c1 serves as a refrigerant derivation pipe. Note that the operation mode will be described later.

[0036] As illustrated in Fig. 1, in refrigeration cycle device 100, receiver 6 is provided in refrigerant pipe 5 between utilization-side heat exchanger 2 and decompressor 3, and the heat source-side internal volume of heat exchange is made larger than the utilization-side internal volume of heat exchange. In a case where the utilization-side heat exchanger 2 operates as a condenser, if the utilization-side internal volume of heat exchange is smaller than the heat source-side internal volume of heat exchange, the refrigerant circulation amount becomes excessive. However, in refrigeration cycle device 100, receiver 6 is provided in refrigerant pipe 5 between the utilization-side heat exchanger 2 and decompressor 3. As a result, refrigeration cycle device 100 can store the liquid refrigerant in receiver 6, can more reliably secure the degree of superheating of the refrigerant sucked into compressor 1, and can suppress a decrease in reliability of compressor 1 due to liquid return.

[0037] Furthermore, as illustrated in Fig. 1, in refrigeration cycle device 100, utilization heat exchange-side connection refrigerant pipe (second refrigerant pipe) 5c1 connected to utilization-side heat exchanger 2 and decompressor-side connection refrigerant pipe (third refrigerant pipe) 5c2 connected to decompressor 3 are inserted into receiver 6, which is a sealed container, vertically upward from the lower side of the container. Furthermore, in refrigeration cycle device 100, an opening end portion of decompressor-side connection refrigerant pipe (third refrigerant pipe) 5c2 is located higher than an opening end portion of utilization heat exchange-side connection refrigerant pipe (second refrigerant pipe) 5c1. In this way, the liquid refrigerant supplied from the utilization-side heat exchanger 2 does not directly flow out to decompressor 3, the degree of superheating of the refrigerant sucked into compressor 1 can be more reliably ensured, and a decrease in reliability of compressor 1 due to liquid return can be suppressed.

[0038] Note that, unlike refrigeration cycle device 100 illustrated in Fig. 1, receiver 6 may be provided in fourth refrigerant pipe 5d between heat source-side heat exchanger 4 and decompressor 3. Hereinafter, this refrigeration cycle device is also referred to as a modified refrigeration cycle device. In the modified refrigeration cycle device, the utilization-side internal volume of heat exchange of utilization-side heat exchanger 2 is made larger than the heat source-side internal volume of heat exchange of heat source-side heat exchanger 4.

[0039] In a case where heat source-side heat exchanger 4 operates as a condenser, if the heat source-side internal volume of heat exchange is smaller than the utilization-side internal volume of heat exchange, the refrigerant circulation amount becomes excessive. However, in the modified refrigeration cycle device, receiver 6 is provided in fourth refrigerant pipe 5d between heat source-side heat exchanger 4 and decompressor 3. As a result, the liquid refrigerant can be stored in receiver 6, the degree of superheating of the refrigerant sucked into compressor 1 can be more reliably secured, and a decrease in reliability of compressor 1 due to liquid return can be suppressed.

[0040] Furthermore, in the modified refrigeration cycle device, the heat source heat exchange-side connection refrigerant pipe connected to heat source-side heat exchanger 4 and decompressor-side connection refrigerant pipe 5c2 connected to decompressor 3 are inserted into receiver 6, which is a sealed container, vertically upward from the lower side of the container. Then, in the modified refrigeration cycle device, the opening end portion of decompressor-side connection refrigerant pipe 5c2 is located higher than the opening end portion of the heat source heat exchange-side connection refrigerant pipe. As described above, in the modified refrigeration cycle device, the heat source heat exchange-side connection refrigerant pipe and decompressor-side connection refrigerant pipe 5c2 are inserted vertically upward from the lower side of the container, and further, the opening end portion of decompressor-side connection refrigerant pipe 5c2 is located higher than the opening end portion of the heat source heat exchange-side connection refrigerant pipe. As a result, the liquid refrigerant supplied from heat source-side heat exchanger 4 does not directly flow out to decompressor 3, the degree of superheating of the refrigerant sucked into compressor 1 can be more reliably ensured, and a decrease in reliability of compressor 1 due to liquid return can be suppressed.

[0041] Refrigeration cycle device 100 has a heating operation mode, a cooling operation mode, a forward cycle defrosting operation mode, and a reverse cycle defrosting operation mode as operation modes.

[0042] In the heating operation mode, a refrigerant flows sequentially through compressor 1, utilization-side heat exchanger 2, decompressor 3, and heat source-side heat exchanger 4, so that utilization-side heat exchanger 2 is used as a condenser and heat source-side heat exchanger 4 is used as an evaporator.

[0043] In the cooling operation mode, a refrigerant flows through compressor 1, heat source-side heat exchanger 4, decompressor 3, and utilization-side heat exchanger 2 in this order, so that utilization-side heat exchanger 2 is used as an evaporator and heat source-side heat exchanger 4 is used as a condenser.

[0044] In the forward cycle defrosting operation mode, a refrigerant flows through compressor 1, utilization-side heat exchanger 2, decompressor 3, and heat source-side heat exchanger 4 in this order, and an opening degree of decompressor 3 is fully opened to use utilization-side heat exchanger 2 and heat source-side heat exchanger 4 as condensers. By using utilization-side heat exchanger 2 and heat source-side heat exchanger 4 as condensers, it is possible to defrost heat source-side heat exchanger 4 while continuing heating by utilization-side heat exchanger 2.

[0045] In the reverse cycle defrosting operation mode, a refrigerant flows through compressor 1, heat source-side heat exchanger 4, decompressor 3, and utilization-side heat exchanger 2 in this order to defrost heat source-side heat exchanger 4 by using heat source-side heat exchanger 4 as a condenser.

[0046] Fig. 2 is a sectional view illustrating compressor 1 used in refrigeration cycle device 100 according to the present example, Fig. 3A is a view taken along line A-A of compressor 1 illustrated in Fig. 2, and Fig. 3B is a perspective view of compressor 1 in a state where piston 32 and vane 33 are separated from each other.

[0047] As illustrated in Fig. 2, compressor 1 includes electric motor unit 20 and compression mechanism unit 30 in sealed container 10. Electric motor unit 20 and compression mechanism unit 30 are coupled by shaft 40.

[0048] Electric motor unit 20 includes stator 21 fixed to an inner surface of sealed container 10 and rotor 22 that rotates in stator 21.

[0049] Compression mechanism unit 30 includes cylinder 31, piston 32 disposed in cylinder 31, and vane 33 (see Figs. 3A and 3B) that partitions the inside of cylinder 31.

[0050] Upper bearing 51 is disposed on one surface of cylinder 31, and lower bearing 52 is disposed on the other surface of cylinder 31.

[0051] Shaft 40 includes main shaft portion 41 to which rotor 22 is attached and which is supported by upper bearing 51, eccentric portion 42 to which piston 32 is attached, and auxiliary shaft portion 43 supported by lower bearing 52. Eccentric portion 42 is disposed in cylinder 31.

[0052] Upper bearing 51 is fixed to sealed container 10. Piston 32 is rotatably fitted to eccentric portion 42 of shaft 40 penetrating inside cylinder 31.

[0053] Upper cover 53 is provided in an upper portion of upper bearing 51. Sound deadening chamber 54 is formed between upper bearing 51 and upper cover 53. A high pressure refrigerant gas compressed by compression mechanism unit 30 is discharged into sound deadening chamber 54. The high pressure refrigerant gas discharged into sound deadening chamber 54 is discharged into sealed container 10.

[0054] Oil reservoir 11 is formed at a bottom portion inside sealed container 10. Oil reservoir 11 stores refrigeration oil. In-shaft oil supply passage 46 is formed in shaft 40 in an axial direction. Communication passage 47 for supplying refrigeration oil to a sliding surface of compression mechanism unit 30 is formed inside eccentric portion 42.

[0055] The refrigeration oil in oil reservoir 11 is introduced into in-shaft oil supply passage 46 from a lower end of shaft 40. A part of the refrigeration oil introduced into in-shaft oil supply passage 46 is supplied from communication passage 47 to the sliding surface of compression mechanism unit 30.

[0056] Suction pipe 12 is connected to a side surface of sealed container 10, and discharge pipe 13 is connected to an upper surface of sealed container 10. Suction pipe 12 guides the refrigerant to compression mechanism unit 30. Discharge pipe 13 guides the refrigerant compressed by compression mechanism unit 30 and discharged into sealed container 10 to the outside of sealed container 10.

[0057] Accumulator 14 is provided on an upstream side of suction pipe 12.

[0058] Accumulator 14 includes outer cylinder 14a, refrigerant suction pipe 14b, and separation plate 14c. Outer cylinder 14a includes, in its upper portion, outer cylinder inlet 14d through which the refrigerant from evaporator 4 is introduced. Refrigerant suction pipe 14b includes suction pipe inlet 14e inside outer cylinder 14a. Separation plate 14c is disposed between outer cylinder inlet 14d and suction pipe inlet 14e.

[0059] Liquid reservoir 14f is formed in an inner bottom portion of outer cylinder 14a. The liquid refrigerant is stored in liquid reservoir 14f. The liquid refrigerant can be stored up to height H of suction pipe inlet 14e. Therefore, the volume of liquid reservoir 14f is up to height H of suction pipe inlet 14e.

[0060] Compressor 1 is driven by an inverter at a plurality of operation frequencies, and is driven in a low rotation speed band in which the rotation speed of the electric motor unit 20 decreases or in a high rotation speed band in which the rotation speed of the electric motor unit 20 increases.

[0061] Compression chamber 34 illustrated in Fig. 3A is formed between upper bearing 51 and lower bearing 52 and between an inner peripheral surface of cylinder 31 and an outer peripheral surface of piston 32.

[0062] Suction pipe 12 is connected to suction passage 35 of compression mechanism unit 30.

[0063] Suction passage 35 is connected to compression chamber 34.

[0064] The rotation of shaft 40 causes piston 32 to revolve.

[0065] Vane 33 reciprocates in vane groove 36 by piston 32 revolving along an inner wall surface of cylinder 31. That is, vane groove 36 in which vane 33 is disposed is formed in cylinder 31.

[0066] Compression chamber 34 is partitioned by vane 33 into suction space 34a communicating with suction passage 35 and compression space 34b communicating with discharge hole 37. A suction volume formed in cylinder 31 is a volume of suction space 34a in a state where suction passage 35 is closed by piston 32, and is a volume in a state where suction space 34a becomes the maximum space.

[0067] The gas refrigerant sucked into compression chamber 34 from suction pipe 12 through suction passage 35 by the revolution of piston 32 is compressed in compression chamber 34 and then discharged from discharge hole 37 into sound deadening chamber 54.

[0068] The refrigerant gas discharged into the sound deadening chamber 54 is discharged into sealed container 10, and is discharged from discharge pipe 13 into the outside of sealed container 10. The high pressure refrigerant gas discharged to the outside of sealed container 10 passes through condenser 2, decompressor 3, and evaporator 4, becomes a low pressure refrigerant gas, and is returned to compression mechanism unit 30 via accumulator 14.

[0069] As illustrated in Fig. 3B, cylindrical groove 32a having an arc angle exceeding 180° is formed on the outer peripheral surface of piston 32. Cylindrical groove 32a extends from one end face to the other end face of piston 32.

[0070] Vane 33 includes vane side surface portion 33a that slides with vane groove 36, cylindrical portion 33b disposed in cylindrical groove 32a, and constricted portion 33c that connects vane side surface portion 33a and cylindrical portion 33b. Cylindrical portion 33b is formed at an end portion of vane 33.

[0071] By engaging cylindrical portion 33b with cylindrical groove 32a, vane 33 operates without being separated from piston 32. Note that piston 32 and vane 33 may be integrally formed.

[0072] Fig. 4 is a flowchart illustrating refrigerant flow channel switching control of refrigeration cycle device 100 according to the present example.

[0073] When the operation mode is a heating operation mode (step S1), controller 80 connects fifth refrigerant pipe 5e and refrigerant suction pipe 5f by refrigerant flow channel switching valve 8, and causes the refrigerant from fifth refrigerant pipe 5e to flow to refrigerant suction pipe 5f (step S2).

[0074] If the degree of superheating estimated from the suction refrigerant temperature or the discharge refrigerant temperature detected by detector 70 is greater than or equal to a threshold (No in step S3), the refrigerant flows through refrigerant suction pipe 5f without switching refrigerant flow channel switching valve 8 (step S2). Note that the estimation of the degree of superheating will be described later.

[0075] In a case where the degree of superheating estimated from the suction refrigerant temperature or the discharge refrigerant temperature detected by detector 70 is lower than the threshold (Yes in step S3), refrigerant flow channel switching valve 8 is switched (step S4), and the refrigerant from fifth refrigerant pipe 5e is caused to flow to heat exchange circuit 61 (step S5).

[0076] When defrosting is not required (No in step S6), the refrigerant from fifth refrigerant pipe 5e is caused to flow to heat exchange circuit 61 without switching refrigerant flow channel switching valve 8 (step S5).

[0077] Note that, in the present example, in a case where defrosting is not required (No in step S6), the refrigerant from fifth refrigerant pipe 5e is caused to flow to heat exchange circuit 61. However, although not illustrated in the drawing, in a case where defrosting is not required (No in step S6) and the degree of superheating estimated from the suction refrigerant temperature or the discharge refrigerant temperature detected by detector 70 is greater than or equal to the threshold, refrigerant flow channel switching valve 8 is switched to flow the refrigerant into refrigerant suction pipe 5f (step S2).

[0078] When detector 70 detects frost formation in heat source-side heat exchanger 4 and controller 80 determines that defrosting is required (Yes in step S6), the forward cycle defrosting operation or the reverse cycle defrosting operation is selected from the detected frost formation state.

[0079] In a case where the forward cycle defrosting operation mode is selected (Yes in step S7), controller 80 switches refrigerant flow channel switching valve 8 (step S8), and performs the defrosting operation with the refrigerant from fifth refrigerant pipe 5e flowing to heat exchange circuit 61 (step S9).

[0080] When the defrosting operation in the forward cycle defrosting operation mode is finished (Yes in step S10), the refrigerant flow channel switching valve 8 is switched (step S11), and the operation returns to an operation in the heating operation mode (step S1).

[0081] In a case where the reverse cycle defrosting operation mode is selected (No in step S7), controller 80 performs the defrosting operation with the refrigerant flowing through refrigerant suction pipe 5f without switching refrigerant flow channel switching valve 8 (step S12).

[0082] When the defrosting operation in the reverse cycle defrosting operation mode is finished (Yes in step S13), the operation returns to the operation in the heating operation mode (step S1).

[0083] As described above, refrigeration cycle device 100 causes the refrigerant to flow into refrigerant suction pipe 5f by refrigerant flow channel switching valve 8 when the degree of superheating estimated from the suction refrigerant temperature or the discharge refrigerant temperature detected by detector 70 is greater than or equal to the threshold in the heating operation mode. On the other hand, in a case where the degree of superheating is lower than the threshold, refrigeration cycle device 100 causes the refrigerant to flow to heat exchange circuit 61 by refrigerant flow channel switching valve 8. In this way, in a case where the degree of superheating is insufficient, for example, at a low external air temperature, at the time of starting the operation of compressor 1 or the like, the degree of superheating of the refrigerant sucked into compressor 1 can be sufficiently secured, vane 33 can be suppressed from being damaged by a load due to liquid compression, and a decrease in reliability of compressor 1 due to liquid compression can be suppressed.

[0084] Furthermore, refrigeration cycle device 100 causes the refrigerant to flow to refrigerant suction pipe 5f by refrigerant flow channel switching valve 8 in the heating operation mode, and causes the refrigerant to flow to heat exchange circuit 61 by refrigerant flow channel switching valve 8 in the forward cycle defrosting operation mode. In this way, even in the case of the forward cycle defrosting operation mode, the degree of superheating of the refrigerant sucked into compressor 1 can be sufficiently secured, vane 33 can be prevented from being damaged by the load due to liquid compression, a decrease in reliability of compressor 1 due to liquid compression can be suppressed, and defrosting performance at a low external temperature can be improved.

[0085] Fig. 5A is an explanatory diagram illustrating control of a degree of superheating or a high and low pressure difference of refrigeration cycle device 100 according to the present example. Fig. 5B is a diagram illustrating a relationship between the rotation speed band of compressor 1, and the target degree of superheating and the target high and low pressure difference range.

[0086] As illustrated in Fig. 5A, the degree of superheating (suction SH) can be estimated from, for example, a temperature difference between the suction temperature and the low pressure temperature, and the high and low pressure difference is a difference between hc and hd.

[0087] Controller 80 controls decompressor 3 so that the degree of superheating in a case where the rotation speed of compressor 1 is in the low rotation speed band is smaller than the degree of superheating in a case where the rotation speed is in the high rotation speed band.

[0088] Refrigeration cycle device 100 includes detector 70 that detects a suction refrigerant temperature of a refrigerant sucked into compressor 1 or a discharge refrigerant temperature of a refrigerant discharged from compressor 1. Controller 80 estimates the degree of superheating from the suction refrigerant temperature or the discharge refrigerant temperature detected by detector 70, and controls decompressor 3 so that the degree of superheating falls within a preset target degree of superheating range.

[0089] The target degree of superheating range is set according to the rotation speed band of compressor 1.

[0090] As illustrated in Fig. 5B, for example, in a case where the rotation speed band of compressor 1 is a maximum rotation speed band, a high rotation speed band, a medium rotation speed band, and a minimum rotation speed band, the target degree of superheating ranges corresponding to the respective rotation speed bands are set as follows. That is, the target degree of superheating range in the maximum rotation speed band is set to a range in which the target degree of superheating is maximized, and the target degree of superheating range in the high rotation speed band is set to a range in which the target degree of superheating is smaller than the maximum but larger than the medium. Furthermore, the target degree of superheating range in the medium rotation speed band is set to a range in which the target degree of superheating is smaller than large but larger than the minimum, and the target degree of superheating range in the minimum rotation speed band is set to a range in which the target degree of superheating is the minimum (zero). That is, controller 80 controls decompressor 3 with the degree of superheating set to zero in a case where the rotation speed band of compressor 1 is in the minimum rotation speed band.

[0091] Furthermore, controller 80 controls decompressor 3 such that a high and low pressure difference of the refrigerant before and after decompressor 3 in a case where the rotation speed of compressor 1 is in the low rotation speed band is smaller than the difference in a case where the rotation speed of compressor 1 is in the high rotation speed band.

[0092] Refrigeration cycle device 100 includes detector 70 that detects a high pressure side temperature or a high pressure side pressure of the refrigerant upstream of decompressor 3 and a low pressure side temperature or a low pressure side pressure of the refrigerant downstream of decompressor 3. Controller 80 controls decompressor 3 so that the high and low pressure difference of the refrigerant detected by detector 70 falls within a preset target high and low pressure difference range.

[0093] The target high and low pressure difference range is set according to the rotation speed band of compressor 1.

[0094] As illustrated in Fig. 5B, for example, in a case where the rotation speed band of compressor 1 is the maximum rotation speed band, the high rotation speed band, the medium rotation speed band, and the minimum rotation speed band, the target high and low pressure difference ranges corresponding to the respective rotation speed bands are set as follows. That is, the target high and low pressure difference range in the maximum rotation speed band is set to a range in which the high and low pressure difference is maximized, and the target high and low pressure difference range in the high rotation speed band is set to a range in which the high and low pressure difference is smaller than the maximum but larger than the medium. Furthermore, the high and low pressure difference in the medium rotation speed band is set to a range in which the high and low pressure difference is smaller than large but larger than minimum, and the high and low pressure difference in the minimum rotation speed band is set to minimum. That is, in a case where the rotation speed of compressor 1 is in the minimum rotation speed band, controller 80 controls decompressor 3 with the high and low pressure difference minimized.

[0095] As described above, refrigeration cycle device 100 according to the present example is a refrigeration cycle device in which compressor 1, utilization-side heat exchanger 2, decompressor 3, heat source-side heat exchanger 4, and four-way valve 7 are annularly connected by refrigerant pipe 5. Compressor 1 includes electric motor unit 20 and compression mechanism unit 30 in sealed container 10. Electric motor unit 20 and compression mechanism unit 30 are coupled by shaft 40. Compression mechanism unit 30 includes cylinder 31, piston 32 disposed in cylinder 31, and vane 33 that partitions the inside of cylinder 31. Shaft 40 includes eccentric portion 42. In refrigeration cycle device 100, vane groove 36 in which vane 33 is disposed is formed in cylinder 31. Eccentric portion 42 is disposed in cylinder 31. Piston 32 is fitted to eccentric portion 42. Vane 33 operates without being separated from piston 32. In refrigeration cycle device 100, refrigerant pipe 5 is provided with receiver 6 that stores a part of the refrigerant flowing through refrigerant pipe 5, and the receiver internal volume of receiver 6 is made larger than the difference between the utilization-side internal volume of heat exchange of utilization-side heat exchanger 2 and the heat source-side internal volume of heat exchange of the heat source-side heat exchanger 4 to reduce the liquid refrigerant sucked into cylinder 31. According to the present example, since vane 33 operates without being separated from piston 32, leakage of the refrigerant from the high pressure side to the low pressure side of compression chamber 34 can be prevented. Furthermore, according to the present example, receiver 6 that stores a part of the refrigerant flowing through refrigerant pipe 5 is provided in refrigerant pipe 5, so that the refrigerant can be stored in receiver 6 in a case where the refrigerant is excessive. Therefore, for example, even at the time of a low external air temperature or at the time of starting the operation of compressor 1, the degree of superheating of the refrigerant sucked into compressor 1 can be sufficiently secured, vane 33 can be suppressed from being damaged by a load due to liquid compression, and a decrease in reliability of compressor 1 due to liquid compression can be suppressed. In other words, refrigeration cycle device 100 according to the present example can prevent leakage of the refrigerant from the high pressure side to the low pressure side of compression chamber 34 and suppress liquid compression.

[0096] Furthermore, in refrigeration cycle device 100 according to the present example, receiver 6 is a sealed container, and a refrigerant introduction pipe that introduces the refrigerant into receiver 6 and a refrigerant derivation pipe that derives the refrigerant from receiver 6 are inserted vertically upward from the lower side of the container. As a result, the liquid refrigerant in the container does not flow out of the refrigerant derivation pipe due to inertia, the inflow of the liquid refrigerant into compressor 1 can be suppressed, and a decrease in reliability of compressor 1 due to liquid return can be suppressed.

[0097] Furthermore, in refrigeration cycle device 100 according to the present example, receiver 6 is provided in refrigerant pipe 5 between utilization-side heat exchanger 2 and decompressor 3, and the heat source-side internal volume of heat exchange is made larger than the utilization-side internal volume of heat exchange. In a case where the utilization-side heat exchanger 2 operates as a condenser, if the utilization-side internal volume of heat exchange is smaller than the heat source-side internal volume of heat exchange, the refrigerant circulation amount becomes excessive. However, according to the present example, by providing receiver 6 in refrigerant pipe 5 between utilization-side heat exchanger 2 and decompressor 3, the liquid refrigerant can be stored in receiver 6. Therefore, the degree of superheating of the refrigerant sucked into compressor 1 can be secured more reliably, and a decrease in reliability of compressor 1 due to liquid return can be suppressed.

[0098] Furthermore, in refrigeration cycle device 100 according to the present example, receiver 6 is a sealed container. In the refrigeration cycle device 100, utilization heat exchange-side connection refrigerant pipe 5c1 connected to utilization-side heat exchanger 2 and decompressor-side connection refrigerant pipe 5c2 connected to decompressor 3 are inserted vertically upward from the lower side of the container. In refrigeration cycle device 100, the opening end portion of decompressor-side connection refrigerant pipe 5c2 is located higher than the opening end portion of utilization heat exchange-side connection refrigerant pipe 5c1. As described above, in refrigeration cycle device 100, utilization heat exchange-side connection refrigerant pipe 5c1 and decompressor-side connection refrigerant pipe 5c2 are inserted vertically upward from the lower side of the container, and further, the opening end portion of decompressor-side connection refrigerant pipe 5c2 is located higher than the opening end portion of utilization heat exchange-side connection refrigerant pipe 5c1. As a result, the liquid refrigerant supplied from utilization-side heat exchanger 2 does not directly flow out to decompressor 3, and the degree of superheating of the refrigerant sucked into compressor 1 can be more reliably secured, so that a decrease in reliability of compressor 1 due to liquid return can be suppressed.

[0099] Furthermore, in refrigeration cycle device 100 according to the present example, receiver 6 is provided in fourth refrigerant pipe 5d between heat source-side heat exchanger 4 and decompressor 3, and the utilization-side internal volume of heat exchange is made larger than the heat source-side internal volume of heat exchange. In a case where heat source-side heat exchanger 4 operates as a condenser, if the heat source-side internal volume of heat exchange is smaller than the utilization-side internal volume of heat exchange, the refrigerant circulation amount becomes excessive. However, according to the present example, by providing receiver 6 in fourth refrigerant pipe 5d between heat source-side heat exchanger 4 and decompressor 3, the liquid refrigerant can be stored in receiver 6. Therefore, the degree of superheating of the refrigerant sucked into compressor 1 can be secured more reliably, and a decrease in reliability of compressor 1 due to liquid return can be suppressed.

[0100] Furthermore, in refrigeration cycle device 100 according to the present example, receiver 6 is a sealed container. In refrigeration cycle device 100, the heat source heat exchange-side connection refrigerant pipe connected to heat source-side heat exchanger 4 and decompressor-side connection refrigerant pipe 5c2 connected to decompressor 3 are inserted vertically upward from the lower side of the container. In refrigeration cycle device 100, the opening end portion of decompressor-side connection refrigerant pipe 5c2 is located higher than the opening end portion of the heat source heat exchange-side connection refrigerant pipe. As described above, in refrigeration cycle device 100, the heat source heat exchange-side connection refrigerant pipe and decompressor-side connection refrigerant pipe 5c2 are inserted vertically upward from the lower side of the container, and further, the opening end portion of decompressor-side connection refrigerant pipe 5c2 is located higher than the opening end portion of the heat source heat exchange-side connection refrigerant pipe. This prevents the liquid refrigerant supplied from heat source-side heat exchanger 4 from directly flowing out to decompressor 3. Therefore, the degree of superheating of the refrigerant sucked into compressor 1 can be secured more reliably, and a decrease in reliability of compressor 1 due to liquid return can be suppressed.

[0101] Furthermore, in refrigeration cycle device 100 according to the present example, compressor 1 includes electric motor unit 20 and compression mechanism unit 30 in sealed container 10. Electric motor unit 20 and compression mechanism unit 30 are coupled by shaft 40. Compression mechanism unit 30 includes cylinder 31, piston 32 disposed in cylinder 31, and vane 33 that partitions the inside of cylinder 31. Shaft 40 includes eccentric portion 42. In refrigeration cycle device 100, vane groove 36 in which vane 33 is disposed is formed in cylinder 31. Eccentric portion 42 is disposed in cylinder 31. Piston 32 is fitted to eccentric portion 42. Vane 33 operates without being separated from piston 32. Refrigeration cycle device 100 includes heat storage tank 60 using compressor 1 as a heat source. In refrigeration cycle device 100, refrigerant flow channel switching valve 8 is provided in refrigerant pipe 5 located upstream of suction pipe 12 of compressor 1. Refrigerant flow channel switching valve 8 switches between heat exchange circuit 61 that performs heat exchange in heat storage tank 60 and guides the refrigerant to suction pipe 12, and refrigerant suction pipe 5f that guides the refrigerant to suction pipe 12 without passing through heat exchange circuit 61. According to the present example, since vane 33 operates without being separated from piston 32, leakage of the refrigerant from the high pressure side to the low pressure side of compression chamber 34 can be prevented. Furthermore, according to the present example, by causing the refrigerant to flow through heat exchange circuit 61 that performs heat exchange in heat storage tank 60, the degree of superheating of the refrigerant sucked into compressor 1 can be sufficiently secured, vane 33 can be suppressed from being damaged by a load due to liquid compression, and a decrease in reliability of compressor 1 due to liquid compression can be suppressed.

[0102] Furthermore, refrigeration cycle device 100 according to the present example has the heating operation mode in which the refrigerant sequentially flows through compressor 1, utilization-side heat exchanger 2, decompressor 3, and heat source-side heat exchanger 4 to use utilization-side heat exchanger 2 as a condenser. Furthermore, refrigeration cycle device 100 has the forward cycle defrosting operation mode in which the refrigerant is caused to flow through compressor 1, utilization-side heat exchanger 2, decompressor 3, and heat source-side heat exchanger 4 in this order to defrost the heat source-side heat exchanger 4. Refrigeration cycle device 100 causes the refrigerant to flow to refrigerant suction pipe 5f by refrigerant flow channel switching valve 8 in the heating operation mode, and causes the refrigerant to flow to heat exchange circuit 61 by refrigerant flow channel switching valve 8 in the forward cycle defrosting operation mode. In this way, even in the case of the forward cycle defrosting operation mode, the degree of superheating of the refrigerant sucked into compressor 1 can be sufficiently secured, vane 33 can be prevented from being damaged by the load due to liquid compression, a decrease in reliability of compressor 1 due to liquid compression can be suppressed, and defrosting performance at a low external temperature can be improved.

[0103] Furthermore, in refrigeration cycle device 100 according to the present example, heat storage tank 60 includes a heat generating source such as a heater in addition to compressor 1 as a heat source. In this way, since the heating amount can be increased as necessary in addition to the exhaust heat of compressor 1, the degree of superheating of the refrigerant sucked into compressor 1 can be sufficiently secured.

[0104] Furthermore, in refrigeration cycle device 100 according to the present example, heat exchange circuit 61 includes an inner pipe through which the refrigerant passes, and has grooves or irregularities formed in at least one of the inner surface and the outer surface of the inner pipe. In this way, the heat transfer coefficient can be improved, the heat exchange from heat storage tank 60 to the refrigerant can be promoted, and the degree of superheating of the refrigerant sucked into compressor 1 can be sufficiently secured.

[0105] Furthermore, refrigeration cycle device 100 according to the present example includes detector 70 that detects a suction refrigerant temperature of a refrigerant sucked into compressor 1 or a discharge refrigerant temperature of a refrigerant discharged from compressor 1. Refrigeration cycle device 100 causes the refrigerant to flow as follows according to the degree of superheating estimated from the suction refrigerant temperature or the discharge refrigerant temperature detected by detector 70 in the heating operation mode in which utilization-side heat exchanger 2 is used as a condenser by causing the refrigerant to flow through compressor 1, utilization-side heat exchanger 2, decompressor 3, and heat source-side heat exchanger 4 in order. That is, refrigeration cycle device 100 causes the refrigerant to flow to refrigerant suction pipe 5f by refrigerant flow channel switching valve 8 in a case where the degree of superheating is greater than or equal to the threshold, and causes the refrigerant to flow to heat exchange circuit 61 by the refrigerant flow channel switching valve 8 in a case where the degree of superheating is less than the threshold. In this way, in a case where the degree of superheating is insufficient, for example, at a low external air temperature, at the time of starting the operation of compressor 1 or the like, the degree of superheating of the refrigerant sucked into compressor 1 can be sufficiently secured, vane 33 can be suppressed from being damaged by a load due to liquid compression, and a decrease in reliability of compressor 1 due to liquid compression can be suppressed.

[0106] Furthermore, refrigeration cycle device 100 according to the present example includes detector 70 that detects a suction refrigerant temperature of a refrigerant sucked into compressor 1 or a discharge refrigerant temperature of a refrigerant discharged from compressor 1. Furthermore, refrigeration cycle device 100 includes controller 80 that estimates a degree of superheating from a suction refrigerant temperature or a discharge refrigerant temperature detected by detector 70, and switches refrigerant flow channel switching valve 8 in accordance with the estimated degree of superheating. Controller 80 switches refrigerant flow channel switching valve 8 so that the refrigerant flows to refrigerant suction pipe 5f in a case where the estimated degree of superheating is greater than or equal to the threshold, and switches refrigerant flow channel switching valve 8 so that the refrigerant flows to heat exchange circuit 61 in a case where the degree of superheating is less than the threshold. In this way, in a case where the degree of superheating is insufficient, for example, at a low external air temperature, at the time of starting the operation of compressor 1 or the like, the degree of superheating of the refrigerant sucked into compressor 1 can be sufficiently secured, vane 33 can be suppressed from being damaged by a load due to liquid compression, and a decrease in reliability of compressor 1 due to liquid compression can be suppressed.

[0107] Furthermore, refrigeration cycle device 100 according to the present example is a refrigeration cycle device in which compressor 1, utilization-side heat exchanger 2, decompressor 3, and heat source-side heat exchanger 4 are annularly connected by refrigerant pipe 5, and the refrigeration cycle device includes controller 80 that controls a rotation speed of compressor 1 and a throttle amount of decompressor 3 to adjust a refrigerant circulation amount. Compressor 1 includes electric motor unit 20 and compression mechanism unit 30 in sealed container 10. Electric motor unit 20 and compression mechanism unit 30 are coupled by shaft 40. Compression mechanism unit 30 includes cylinder 31, piston 32 disposed in cylinder 31, and vane 33 that partitions the inside of cylinder 31. Shaft 40 includes eccentric portion 42. Vane groove 36 in which vane 33 is disposed is formed in cylinder 31. Eccentric portion 42 is disposed in cylinder 31. Piston 32 is fitted to eccentric portion 42. Vane 33 operates without being separated from piston 32. Controller 80 controls decompressor 3 so that the degree of superheating in a case where the rotation speed of compressor 1 is in the low rotation speed band is smaller than the degree of superheating in a case where the rotation speed is in the high rotation speed band. According to the present example, since vane 33 operates without being separated from piston 32, leakage of the refrigerant from the high pressure side to the low pressure side of compression chamber 34 can be prevented. Furthermore, according to the present example, in a case where the rotation speed of compressor 1 is in the low rotation speed band, an amount of liquid return decreases due to a decrease in a refrigerant circulation amount. Therefore, liquid compression can be suppressed even when the degree of superheating is reduced, and operation can be performed with high efficiency by reducing the degree of superheating.

[0108] Furthermore, refrigeration cycle device 100 according to the present example includes detector 70 that detects a suction refrigerant temperature of a refrigerant sucked into compressor 1 or a discharge refrigerant temperature of a refrigerant discharged from compressor 1. Controller 80 estimates the degree of superheating from the suction refrigerant temperature or the discharge refrigerant temperature detected by detector 70, and controls decompressor 3 so that the degree of superheating falls within a preset target degree of superheating range. As described above, by controlling the degree of superheating to fall within the target degree of superheating range, it is possible to suppress liquid compression and realize highly efficient operation.

[0109] Furthermore, in refrigeration cycle device 100 according to the present example, the target degree of superheating range is set according to the rotation speed band of compressor 1. As described above, by setting the target degree of superheating range according to the rotation speed band of compressor 1, it is possible to suppress liquid compression and realize highly efficient operation.

[0110] Furthermore, in refrigeration cycle device 100 according to the present example, controller 80 controls decompressor 3 with the degree of superheating set to zero in a case where the rotation speed of compressor 1 is in the minimum rotation speed band. As described above, when the degree of superheating is zero, the refrigerant is in a wet state and a liquid refrigerant is mixed. However, when the rotation speed of compressor 1 is in the minimum rotation speed band, the load due to liquid compression is small and vane 33 is not damaged. By setting the degree of superheating to zero, the compression ratio is reduced, so that operation can be performed with high efficiency.

[0111] Furthermore, refrigeration cycle device 100 according to the present example is a refrigeration cycle device in which compressor 1, utilization-side heat exchanger 2, decompressor 3, and heat source-side heat exchanger 4 are annularly connected by refrigerant pipe 5, and the refrigeration cycle device includes controller 80 that controls a rotation speed of compressor 1 and a throttle amount of decompressor 3 to adjust a refrigerant circulation amount. Compressor 1 includes electric motor unit 20 and compression mechanism unit 30 in sealed container 10. Electric motor unit 20 and compression mechanism unit 30 are coupled by shaft 40. Compression mechanism unit 30 includes cylinder 31, piston 32 disposed in cylinder 31, and vane 33 that partitions the inside of cylinder 31. Shaft 40 includes eccentric portion 42. Vane groove 36 in which vane 33 is disposed is formed in cylinder 31. Eccentric portion 42 is disposed in cylinder 31. Piston 32 is fitted to eccentric portion 42. Vane 33 operates without being separated from piston 32. Controller 80 controls decompressor 3 so as to reduce a high and low pressure difference of the refrigerant before and after decompressor 3 in a case where the rotation speed of compressor 1 is in the low rotation speed band as compared with the difference in a case where the rotation speed of compressor 1 is in the high rotation speed band. According to the present example, since vane 33 operates without being separated from piston 32, leakage of the refrigerant from the high pressure side to the low pressure side of compression chamber 34 can be prevented. Furthermore, according to the present example, in a case where the rotation speed of compressor 1 is in the low rotation speed band, an amount of liquid return decreases due to a decrease in a refrigerant circulation amount. Therefore, liquid compression can be suppressed even if a high and low pressure difference of the refrigerant before and after decompressor 3 is reduced, and the operation can be performed with high efficiency by reducing the high and low pressure difference of the refrigerant before and after decompressor 3. Furthermore, according to the present example, in a case where the rotation speed of compressor 1 is in the low rotation speed band, a compression load can be reduced by reducing the high and low pressure difference of the refrigerant before and after decompressor 3, and the stability of the compressor rotation can be secured.

[0112] Furthermore, refrigeration cycle device 100 according to the present example includes detector 70 that detects the high pressure side temperature or the high pressure side pressure of the refrigerant upstream of decompressor 3 and the low pressure side temperature or the low pressure side pressure of the refrigerant downstream of decompressor 3. Controller 80 controls the decompressor 3 so that the high and low pressure difference of the refrigerant detected by detector 70 falls within a preset target high and low pressure difference range. As described above, by controlling the high and low pressure difference to fall within the target high and low pressure difference range, it is possible to suppress liquid compression, perform highly efficient operation, and ensure stability of compressor rotation.

[0113] Furthermore, in refrigeration cycle device 100 according to the present example, the target high and low pressure difference range is set according to the rotation speed band of compressor 1. As described above, by setting the target high and low pressure difference range according to the rotation speed band of compressor 1, it is possible to suppress liquid compression, perform highly efficient operation, and ensure stability of compressor rotation.

[0114] Furthermore, in refrigeration cycle device 100 according to the present example, in a case where the rotation speed of compressor 1 is in the minimum rotation speed band, controller 80 controls decompressor 3 with the high and low pressure difference minimized. As described above, the high and low pressure difference of the refrigerant before and after decompressor 3 is reduced, so that the liquid refrigerant may be mixed. However, when the rotation speed of compressor 1 is in the minimum rotation speed band, the load due to the liquid compression is small, vane 33 is not damaged, and the high and low pressure difference of the refrigerant is small, so that the operation can be performed with high efficiency, and the stability of the compressor rotation can be secured.

[0115] The refrigeration cycle device of the present disclosure is applicable to, for example, a hot water heating device, an air conditioning device, a water heater, a refrigerator, a showcase, a chiller, a dehumidifier, or a freezing machine.

Examples

examples

[Examples]

[0015]Hereinafter, examples of the present disclosure will be described in detail with reference to the drawings. However, the drawings described in the following examples are schematic views, and the ratio of the size and the thickness of each component does not necessarily reflect the actual dimension ratio. Furthermore, the configurations described in the following examples are merely examples of the present disclosure. The present disclosure is not limited to the following examples, and various modifications can be made according to the design and the like as long as the effects of the present disclosure can be achieved. Note that "vertically upward" in the following examples means that it is intended to be vertically upward, but includes a portion slightly deviated from vertically upward due to an error or the like. Specifically, vertically upward means within 90° ± 5°, preferably within 90° ± 3°, and more preferably within 90° ± 1°.

[0016]Fig. 1 is a configuration dia...

BACKGROUND1. Technical Field

[0001] The present disclosure relates to a refrigeration cycle device using a compressor in which a vane operates without moving away from a piston.2. Description of the Related Art

[0002] The rotary compressor disclosed in PTL 1 has a configuration in which a piston and a vane that partitions a compression chamber and a suction chamber in a cylinder are integrally provided. A protruding-side distal end portion of the vane is received in a receiving groove of a rotatably supportive columnar support, and the receiving groove penetrates from one side to the other side of an outer peripheral surface. Therefore, since the piston and the vane do not repeat separation and contact, refrigeration oil does not deteriorate or hydrolyze, sludge is not generated and does not adhere to the inside of a refrigeration cycle, and a highly reliable refrigeration cycle device can be provided.Citation ListPatent Literature

[0003] PTL 1: Unexamined Japanese Patent Publication No. H08-121364SUMMARY

[0004] However, since the piston and the vane are integrally configured, when a liquid refrigerant is supplied to the compressor, the refrigerant does not leak from a high pressure side to a low pressure side in the compression chamber, and thus liquid compression occurs. Therefore, a large load is applied to the vane, and the vane or a component constituting the compressor may be damaged. Furthermore, even in the case of the low rotation operation of the compressor, since the refrigerant cannot be released from the high pressure side to the low pressure side, the compression load does not decrease, and the rotation operation may become unstable.

[0005] Therefore, the present disclosure provides a refrigeration cycle device capable of suppressing leakage of a refrigerant from a high pressure side to a low pressure side of a compression chamber and suppressing liquid compression.

[0006] A refrigeration cycle device according to one aspect of the present disclosure is a refrigeration cycle device in which a compressor, a utilization-side heat exchanger, a decompressor, a heat source-side heat exchanger, and a four-way valve are annularly connected by a refrigerant pipe. The compressor includes, in a sealed container, an electric motor unit and a compression mechanism unit. The electric motor unit and the compression mechanism unit are coupled by a shaft. The compression mechanism unit includes a cylinder, a piston disposed in the cylinder, and a vane that partitions an inside of the cylinder. The shaft includes an eccentric portion. A vane groove in which the vane is disposed is formed in the cylinder. The eccentric portion is disposed in the cylinder. The piston is fitted to the eccentric portion. The vane operates without being separated from the piston. In the refrigeration cycle device, a receiver that stores a part of a refrigerant flowing through the refrigerant pipe is provided in the refrigerant pipe, and a receiver internal volume of the receiver is made larger than a difference between a utilization-side internal volume of heat exchange of the utilization-side heat exchanger and a heat source-side internal volume of heat exchange of the heat source-side heat exchanger to reduce a liquid refrigerant sucked into the cylinder.

[0007] According to the present disclosure, leakage of a refrigerant from a high pressure side to a low pressure side of a compression chamber can be prevented, and liquid compression can be suppressed.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Fig. 1 is a configuration diagram illustrating a refrigeration cycle device according to an example of the present disclosure; Fig. 2 is a sectional view illustrating a compressor used in the refrigeration cycle device according to the present example; Fig. 3A is an A-A arrow view of the compressor illustrated in Fig. 2; Fig. 3B is a perspective view of the compressor illustrated in Fig. 2 in a state where a piston and a vane are separated from each other; Fig. 4 is a flowchart illustrating refrigerant flow channel switching control of the refrigeration cycle device according to the present example; Fig. 5A is an explanatory diagram illustrating control of a degree of superheating or a high and low pressure difference of the refrigeration cycle device according to the present example; and Fig. 5B is a diagram illustrating a relationship between a rotation speed band of the compressor, and a target degree of superheating and a target high and low pressure difference range in the refrigeration cycle device according to the present example. DETAILED DESCRIPTIONS

[0009] A refrigeration cycle device according to a first exemplary embodiment of the present disclosure is a refrigeration cycle device in which a compressor, a utilization-side heat exchanger, a decompressor, a heat source-side heat exchanger, and a four-way valve are annularly connected by a refrigerant pipe. The compressor includes, in a sealed container, an electric motor unit and a compression mechanism unit. The electric motor unit and the compression mechanism unit are coupled by a shaft. The compression mechanism unit includes a cylinder, a piston disposed in the cylinder, and a vane that partitions an inside of the cylinder. The shaft includes an eccentric portion. A vane groove in which the vane is disposed is formed in the cylinder. The eccentric portion is disposed in the cylinder. The piston is fitted to the eccentric portion. The vane operates without being separated from the piston. In the refrigeration cycle device according to the present exemplary embodiment, a receiver that stores a part of a refrigerant flowing through the refrigerant pipe is provided in the refrigerant pipe, and a receiver internal volume of the receiver is made larger than a difference between a utilization-side internal volume of heat exchange of the utilization-side heat exchanger and a heat source-side internal volume of heat exchange of the heat source-side heat exchanger to reduce a liquid refrigerant sucked into the cylinder. According to the present exemplary embodiment, the vane operates without being separated from the piston. Therefore, leakage of a refrigerant from a high pressure side to a low pressure side of a compression chamber can be prevented. Furthermore, according to the present exemplary embodiment, the receiver that stores a part of a refrigerant flowing through the refrigerant pipe is provided in the refrigerant pipe, so that the refrigerant can be stored in the receiver in a case where the refrigerant is excessive. Therefore, for example, even at the time of low external air temperature or at the time of starting the operation of the compressor, the degree of superheating of the refrigerant sucked into the compressor can be sufficiently secured, the vane can be suppressed from being damaged by a load due to liquid compression, and a decrease in reliability of the compressor due to liquid compression can be suppressed.

[0010] In a refrigeration cycle device according to a second exemplary embodiment of the present disclosure, in the refrigeration cycle device according to the first exemplary embodiment, the receiver includes a sealed container. Furthermore, in the refrigeration cycle device according to the present exemplary embodiment, a refrigerant introduction pipe that introduces the refrigerant into the receiver and a refrigerant derivation pipe that derives the refrigerant from the receiver are inserted vertically upward from a lower side of the container. According to the present exemplary embodiment, by inserting the refrigerant introduction pipe and the refrigerant derivation pipe vertically upward from the lower side of the container, the liquid refrigerant in the container does not flow out of the refrigerant derivation pipe due to inertia. Therefore, the inflow of the liquid refrigerant into the compressor can be suppressed, and the decrease in reliability of the compressor due to liquid return can be suppressed.

[0011] In a refrigeration cycle device according to a third exemplary embodiment of the present disclosure, in the refrigeration cycle device according to the first exemplary embodiment, the receiver is provided in the refrigerant pipe between the utilization-side heat exchanger and the decompressor, and the heat source-side internal volume of heat exchange is made larger than the utilization-side internal volume of heat exchange. In a case where the utilization-side heat exchanger operates as a condenser, if the utilization-side internal volume of heat exchange is smaller than the heat source-side internal volume of heat exchange, a refrigerant circulation amount becomes excessive. However, according to the present exemplary embodiment, by providing the receiver in the refrigerant pipe between the utilization-side heat exchanger and the decompressor, the liquid refrigerant can be stored in the receiver, the degree of superheating of the refrigerant sucked into the compressor can be more reliably secured, and a decrease in reliability of the compressor due to liquid return can be suppressed.

[0012] In a refrigeration cycle device according to a fourth exemplary embodiment of the present disclosure, in the refrigeration cycle device according to the third exemplary embodiment, the receiver includes a sealed container. Furthermore, in the refrigeration cycle device according to the present exemplary embodiment, a utilization heat exchange-side connection refrigerant pipe connected to the utilization-side heat exchanger and a decompressor-side connection refrigerant pipe connected to the decompressor are inserted vertically upward from a lower side of the container. Furthermore, in the refrigeration cycle device according to the present exemplary embodiment, an opening end portion of the decompressor-side connection refrigerant pipe is located higher than an opening end portion of the utilization heat exchange-side connection refrigerant pipe. As described above, in the refrigeration cycle device according to the present exemplary embodiment, the utilization heat exchange-side connection refrigerant pipe and the decompressor-side connection refrigerant pipe are inserted vertically upward from the lower side of the container, and further, the opening end portion of the decompressor-side connection refrigerant pipe is located higher than the opening end portion of the utilization heat exchange-side connection refrigerant pipe. As a result, the liquid refrigerant supplied from the utilization-side heat exchanger does not directly flow out to the decompressor, the degree of superheating of the refrigerant sucked into the compressor can be more reliably secured, and a decrease in reliability of the compressor due to liquid return can be suppressed.

[0013] In a refrigeration cycle device according to a fifth exemplary embodiment of the present disclosure, in the refrigeration cycle device according to the first exemplary embodiment, the receiver is provided in the refrigerant pipe between the heat source-side heat exchanger and the decompressor, and the utilization-side internal volume of heat exchange is made larger than the heat source-side internal volume of heat exchange. In a case where the heat source-side heat exchanger operates as a condenser, if the heat source-side internal volume of heat exchange is smaller than the utilization-side internal volume of heat exchange, a refrigerant circulation amount becomes excessive. However, according to the present exemplary embodiment, by providing the receiver in the refrigerant pipe between the heat source-side heat exchanger and the decompressor, the liquid refrigerant can be stored in the receiver, the degree of superheating of the refrigerant sucked into the compressor can be more reliably secured, and a decrease in reliability of the compressor due to liquid return can be suppressed.

[0014] In a refrigeration cycle device according to a sixth exemplary embodiment of the present disclosure, in the refrigeration cycle device according to the fifth exemplary embodiment, the receiver includes a sealed container. Furthermore, in the present refrigeration cycle device, a heat source heat exchange-side connection refrigerant pipe connected to the heat source-side heat exchanger and a decompressor-side connection refrigerant pipe connected to the decompressor are inserted vertically upward from a lower side of the container. Furthermore, in the present refrigeration cycle device, an opening end portion of the decompressor-side connection refrigerant pipe is located higher than an opening end portion of the heat source heat exchange-side connection refrigerant pipe. As described above, in the refrigeration cycle device according to the present exemplary embodiment, the heat source heat exchange-side connection refrigerant pipe and the decompressor-side connection refrigerant pipe are inserted vertically upward from the lower side of the container, and further, the opening end portion of the decompressor-side connection refrigerant pipe is located higher than the opening end portion of the heat source heat exchange-side connection refrigerant pipe. As a result, the liquid refrigerant supplied from the heat source-side heat exchanger does not directly flow out to the decompressor, the degree of superheating of the refrigerant sucked into the compressor can be more reliably ensured, and a decrease in reliability of the compressor due to liquid return can be suppressed.[Examples]

[0015] Hereinafter, examples of the present disclosure will be described in detail with reference to the drawings. However, the drawings described in the following examples are schematic views, and the ratio of the size and the thickness of each component does not necessarily reflect the actual dimension ratio. Furthermore, the configurations described in the following examples are merely examples of the present disclosure. The present disclosure is not limited to the following examples, and various modifications can be made according to the design and the like as long as the effects of the present disclosure can be achieved. Note that "vertically upward" in the following examples means that it is intended to be vertically upward, but includes a portion slightly deviated from vertically upward due to an error or the like. Specifically, vertically upward means within 90° ± 5°, preferably within 90° ± 3°, and more preferably within 90° ± 1°.

[0016] Fig. 1 is a configuration diagram illustrating refrigeration cycle device 100 according to an example of the present disclosure.

[0017] In refrigeration cycle device 100 according to the present example, compressor 1, utilization-side heat exchanger 2, decompressor 3, and heat source-side heat exchanger 4 are annularly connected by refrigerant pipe 5.

[0018] In refrigeration cycle device 100, refrigerant pipe 5 is provided with receiver 6 that stores a part of the refrigerant flowing through refrigerant pipe 5.

[0019] Receiver 6 is preferably provided in refrigerant pipe 5 between utilization-side heat exchanger 2 and decompressor 3. Receiver 6 is a sealed container, and a receiver internal volume of receiver 6 is made larger than a difference between a utilization-side internal volume of heat exchange of utilization-side heat exchanger 2 and a heat source-side internal volume of heat exchange of heat source-side heat exchanger 4.

[0020] In refrigeration cycle device 100, four-way valve 7 is provided in refrigerant pipe 5. That is, in refrigeration cycle device 100, compressor 1, utilization-side heat exchanger 2, decompressor 3, heat source-side heat exchanger 4, and four-way valve 7 may be annularly connected by refrigerant pipe 5.

[0021] Four-way valve 7 switches the refrigerant discharged from compressor 1 to flow to utilization-side heat exchanger 2 or heat source-side heat exchanger 4.

[0022] In a case where four-way valve 7 causes the refrigerant discharged from compressor 1 to flow into utilization-side heat exchanger 2, the refrigerant discharged from compressor 1 flows through utilization-side heat exchanger 2, decompressor 3, and heat source-side heat exchanger 4, and then returns to compressor 1 by four-way valve 7.

[0023] In a case where four-way valve 7 causes the refrigerant discharged from compressor 1 to flow into heat source-side heat exchanger 4, the refrigerant discharged from compressor 1 flows through heat source-side heat exchanger 4, decompressor 3, and utilization-side heat exchanger 2, and then returns to compressor 1 by four-way valve 7.

[0024] Refrigerant pipe 5 includes refrigerant discharge pipe 5a, first refrigerant pipe 5b, second refrigerant pipe 5c1, third refrigerant pipe 5c2, fourth refrigerant pipe 5d, fifth refrigerant pipe 5e, and refrigerant suction pipe 5f. Refrigerant discharge pipe 5a connects discharge pipe 13 (see Fig. 2) of compressor 1 and four-way valve 7. First refrigerant pipe 5b connects four-way valve 7 and utilization-side heat exchanger 2. Second refrigerant pipe 5c1 connects utilization-side heat exchanger 2 and receiver 6. Third refrigerant pipe 5c2 connects receiver 6 and decompressor 3. Fourth refrigerant pipe 5d connects decompressor 3 and heat source-side heat exchanger 4. Fifth refrigerant pipe 5e connects heat source-side heat exchanger 4 and four-way valve 7. Refrigerant suction pipe 5f connects four-way valve 7 and suction pipe 12 (see Fig. 2) of compressor 1.

[0025] Accumulator 14 is provided in refrigerant suction pipe 5f. Furthermore, refrigerant flow channel switching valve 8 is provided in refrigerant pipe 5 (refrigerant suction pipe 5f) located upstream of suction pipe 12 of compressor 1.

[0026] Refrigeration cycle device 100 includes heat storage tank 60 using compressor 1 as a heat source.

[0027] Heat storage tank 60 is provided around compressor 1 so as to surround compressor 1, and absorbs heat generated from compressor 1. Heat storage tank 60 includes, for example, a heat storage material such as an ethylene glycol aqueous solution, and stores the heat of sealed container 10 (see Fig. 2) of compressor 1 in the heat storage material. Then, the heat of the stored heat storage material is applied to heat exchange circuit 61. Heat storage tank 60 preferably includes a heat generating source such as a heater in addition to compressor 1 as a heat source.

[0028] Heat exchange circuit 61 includes an inner pipe through which a refrigerant passes, and in particular, the inner pipe that exchanges heat with the heat storage material in heat storage tank 60 preferably has grooves or irregularities formed on at least one of an inner surface and an outer surface of the inner pipe. By forming the grooves or irregularities on the inner surface and the outer surface of the inner pipe, the heat transfer coefficient can be improved, and heat exchange from heat storage tank 60 to the refrigerant flowing through the inner pipe can be promoted.

[0029] Refrigerant flow channel switching valve 8 switches between heat exchange circuit 61 that performs heat exchange in heat storage tank 60 and guides the refrigerant to suction pipe 12, and refrigerant suction pipe 5f that guides the refrigerant to suction pipe 12 without passing through heat exchange circuit 61.

[0030] Refrigeration cycle device 100 includes detector 70, which is any one of detector 70a, detector 70b, detector 70c, detector 70d, detector 70e, and detector 70f. Detector 70a detects the temperature or pressure of the refrigerant flowing through refrigerant discharge pipe 5a. Detector 70b detects the temperature or pressure of the refrigerant flowing through first refrigerant pipe 5b. Detector 70c detects the temperature or pressure of the refrigerant flowing through second refrigerant pipe 5c1 or third refrigerant pipe 5c2. Detector 70d detects the temperature or pressure of the refrigerant flowing through fourth refrigerant pipe 5d. Detector 70e detects the temperature or pressure of the refrigerant flowing through fifth refrigerant pipe 5e. Detector 70f detects the temperature or pressure of the refrigerant flowing through refrigerant suction pipe 5f.

[0031] Refrigeration cycle device 100 includes controller 80 that controls a rotation speed of compressor 1 and a throttle amount of decompressor 3 to adjust a refrigerant circulation amount. Controller 80 controls the rotation speed (frequency) of compressor 1, an opening degree of decompressor 3, switching of four-way valve 7, and switching of refrigerant flow channel switching valve 8 on the basis of a detection value from detector 70 and instruction data from an input unit. Note that controller 80 may be a hardware circuit designed exclusively for realizing the control of refrigeration cycle device 100. Furthermore, controller 80 may realize the control of refrigeration cycle device 100 by a processor executing a program stored in a memory, that is, by the cooperation of hardware and software. Although the program to be executed by the processor is here to be recorded in advance in the memory, the control program may be provided by being recorded in a non-temporary recording medium such as a memory card, or may be provided through a telecommunication line such as the Internet.

[0032] End portions of second refrigerant pipe 5c1 and third refrigerant pipe 5c2 are inserted into receiver 6 from a lower portion of receiver 6.

[0033] In refrigeration cycle device 100, a refrigerant introduction pipe that introduces a refrigerant into receiver 6 and a refrigerant derivation pipe that derives the refrigerant from receiver 6 are inserted into receiver 6 that is a sealed container in a vertically upward direction from a lower side of the container. As described above, by inserting the refrigerant introduction pipe and the refrigerant derivation pipe vertically upward from the lower side of the container, liquid refrigerant in the container does not flow out of the refrigerant derivation pipe due to inertia. Therefore, the inflow of the liquid refrigerant into compressor 1 can be suppressed, and the decrease in reliability of compressor 1 due to liquid return can be suppressed.

[0034] When the operation mode is a heating operation mode and a forward cycle defrosting operation mode, second refrigerant pipe 5c1 serves as a refrigerant introduction pipe, and third refrigerant pipe 5c2 serves as a refrigerant derivation pipe.

[0035] Furthermore, when the operation mode is a cooling operation mode and a reverse cycle defrosting operation mode, third refrigerant pipe 5c2 serves as a refrigerant introduction pipe, and second refrigerant pipe 5c1 serves as a refrigerant derivation pipe. Note that the operation mode will be described later.

[0036] As illustrated in Fig. 1, in refrigeration cycle device 100, receiver 6 is provided in refrigerant pipe 5 between utilization-side heat exchanger 2 and decompressor 3, and the heat source-side internal volume of heat exchange is made larger than the utilization-side internal volume of heat exchange. In a case where the utilization-side heat exchanger 2 operates as a condenser, if the utilization-side internal volume of heat exchange is smaller than the heat source-side internal volume of heat exchange, the refrigerant circulation amount becomes excessive. However, in refrigeration cycle device 100, receiver 6 is provided in refrigerant pipe 5 between the utilization-side heat exchanger 2 and decompressor 3. As a result, refrigeration cycle device 100 can store the liquid refrigerant in receiver 6, can more reliably secure the degree of superheating of the refrigerant sucked into compressor 1, and can suppress a decrease in reliability of compressor 1 due to liquid return.

[0037] Furthermore, as illustrated in Fig. 1, in refrigeration cycle device 100, utilization heat exchange-side connection refrigerant pipe (second refrigerant pipe) 5c1 connected to utilization-side heat exchanger 2 and decompressor-side connection refrigerant pipe (third refrigerant pipe) 5c2 connected to decompressor 3 are inserted into receiver 6, which is a sealed container, vertically upward from the lower side of the container. Furthermore, in refrigeration cycle device 100, an opening end portion of decompressor-side connection refrigerant pipe (third refrigerant pipe) 5c2 is located higher than an opening end portion of utilization heat exchange-side connection refrigerant pipe (second refrigerant pipe) 5c1. In this way, the liquid refrigerant supplied from the utilization-side heat exchanger 2 does not directly flow out to decompressor 3, the degree of superheating of the refrigerant sucked into compressor 1 can be more reliably ensured, and a decrease in reliability of compressor 1 due to liquid return can be suppressed.

[0038] Note that, unlike refrigeration cycle device 100 illustrated in Fig. 1, receiver 6 may be provided in fourth refrigerant pipe 5d between heat source-side heat exchanger 4 and decompressor 3. Hereinafter, this refrigeration cycle device is also referred to as a modified refrigeration cycle device. In the modified refrigeration cycle device, the utilization-side internal volume of heat exchange of utilization-side heat exchanger 2 is made larger than the heat source-side internal volume of heat exchange of heat source-side heat exchanger 4.

[0039] In a case where heat source-side heat exchanger 4 operates as a condenser, if the heat source-side internal volume of heat exchange is smaller than the utilization-side internal volume of heat exchange, the refrigerant circulation amount becomes excessive. However, in the modified refrigeration cycle device, receiver 6 is provided in fourth refrigerant pipe 5d between heat source-side heat exchanger 4 and decompressor 3. As a result, the liquid refrigerant can be stored in receiver 6, the degree of superheating of the refrigerant sucked into compressor 1 can be more reliably secured, and a decrease in reliability of compressor 1 due to liquid return can be suppressed.

[0040] Furthermore, in the modified refrigeration cycle device, the heat source heat exchange-side connection refrigerant pipe connected to heat source-side heat exchanger 4 and decompressor-side connection refrigerant pipe 5c2 connected to decompressor 3 are inserted into receiver 6, which is a sealed container, vertically upward from the lower side of the container. Then, in the modified refrigeration cycle device, the opening end portion of decompressor-side connection refrigerant pipe 5c2 is located higher than the opening end portion of the heat source heat exchange-side connection refrigerant pipe. As described above, in the modified refrigeration cycle device, the heat source heat exchange-side connection refrigerant pipe and decompressor-side connection refrigerant pipe 5c2 are inserted vertically upward from the lower side of the container, and further, the opening end portion of decompressor-side connection refrigerant pipe 5c2 is located higher than the opening end portion of the heat source heat exchange-side connection refrigerant pipe. As a result, the liquid refrigerant supplied from heat source-side heat exchanger 4 does not directly flow out to decompressor 3, the degree of superheating of the refrigerant sucked into compressor 1 can be more reliably ensured, and a decrease in reliability of compressor 1 due to liquid return can be suppressed.

[0041] Refrigeration cycle device 100 has a heating operation mode, a cooling operation mode, a forward cycle defrosting operation mode, and a reverse cycle defrosting operation mode as operation modes.

[0042] In the heating operation mode, a refrigerant flows sequentially through compressor 1, utilization-side heat exchanger 2, decompressor 3, and heat source-side heat exchanger 4, so that utilization-side heat exchanger 2 is used as a condenser and heat source-side heat exchanger 4 is used as an evaporator.

[0043] In the cooling operation mode, a refrigerant flows through compressor 1, heat source-side heat exchanger 4, decompressor 3, and utilization-side heat exchanger 2 in this order, so that utilization-side heat exchanger 2 is used as an evaporator and heat source-side heat exchanger 4 is used as a condenser.

[0044] In the forward cycle defrosting operation mode, a refrigerant flows through compressor 1, utilization-side heat exchanger 2, decompressor 3, and heat source-side heat exchanger 4 in this order, and an opening degree of decompressor 3 is fully opened to use utilization-side heat exchanger 2 and heat source-side heat exchanger 4 as condensers. By using utilization-side heat exchanger 2 and heat source-side heat exchanger 4 as condensers, it is possible to defrost heat source-side heat exchanger 4 while continuing heating by utilization-side heat exchanger 2.

[0045] In the reverse cycle defrosting operation mode, a refrigerant flows through compressor 1, heat source-side heat exchanger 4, decompressor 3, and utilization-side heat exchanger 2 in this order to defrost heat source-side heat exchanger 4 by using heat source-side heat exchanger 4 as a condenser.

[0046] Fig. 2 is a sectional view illustrating compressor 1 used in refrigeration cycle device 100 according to the present example, Fig. 3A is a view taken along line A-A of compressor 1 illustrated in Fig. 2, and Fig. 3B is a perspective view of compressor 1 in a state where piston 32 and vane 33 are separated from each other.

[0047] As illustrated in Fig. 2, compressor 1 includes electric motor unit 20 and compression mechanism unit 30 in sealed container 10. Electric motor unit 20 and compression mechanism unit 30 are coupled by shaft 40.

[0048] Electric motor unit 20 includes stator 21 fixed to an inner surface of sealed container 10 and rotor 22 that rotates in stator 21.

[0049] Compression mechanism unit 30 includes cylinder 31, piston 32 disposed in cylinder 31, and vane 33 (see Figs. 3A and 3B) that partitions the inside of cylinder 31.

[0050] Upper bearing 51 is disposed on one surface of cylinder 31, and lower bearing 52 is disposed on the other surface of cylinder 31.

[0051] Shaft 40 includes main shaft portion 41 to which rotor 22 is attached and which is supported by upper bearing 51, eccentric portion 42 to which piston 32 is attached, and auxiliary shaft portion 43 supported by lower bearing 52. Eccentric portion 42 is disposed in cylinder 31.

[0052] Upper bearing 51 is fixed to sealed container 10. Piston 32 is rotatably fitted to eccentric portion 42 of shaft 40 penetrating inside cylinder 31.

[0053] Upper cover 53 is provided in an upper portion of upper bearing 51. Sound deadening chamber 54 is formed between upper bearing 51 and upper cover 53. A high pressure refrigerant gas compressed by compression mechanism unit 30 is discharged into sound deadening chamber 54. The high pressure refrigerant gas discharged into sound deadening chamber 54 is discharged into sealed container 10.

[0054] Oil reservoir 11 is formed at a bottom portion inside sealed container 10. Oil reservoir 11 stores refrigeration oil. In-shaft oil supply passage 46 is formed in shaft 40 in an axial direction. Communication passage 47 for supplying refrigeration oil to a sliding surface of compression mechanism unit 30 is formed inside eccentric portion 42.

[0055] The refrigeration oil in oil reservoir 11 is introduced into in-shaft oil supply passage 46 from a lower end of shaft 40. A part of the refrigeration oil introduced into in-shaft oil supply passage 46 is supplied from communication passage 47 to the sliding surface of compression mechanism unit 30.

[0056] Suction pipe 12 is connected to a side surface of sealed container 10, and discharge pipe 13 is connected to an upper surface of sealed container 10. Suction pipe 12 guides the refrigerant to compression mechanism unit 30. Discharge pipe 13 guides the refrigerant compressed by compression mechanism unit 30 and discharged into sealed container 10 to the outside of sealed container 10.

[0057] Accumulator 14 is provided on an upstream side of suction pipe 12.

[0058] Accumulator 14 includes outer cylinder 14a, refrigerant suction pipe 14b, and separation plate 14c. Outer cylinder 14a includes, in its upper portion, outer cylinder inlet 14d through which the refrigerant from evaporator 4 is introduced. Refrigerant suction pipe 14b includes suction pipe inlet 14e inside outer cylinder 14a. Separation plate 14c is disposed between outer cylinder inlet 14d and suction pipe inlet 14e.

[0059] Liquid reservoir 14f is formed in an inner bottom portion of outer cylinder 14a. The liquid refrigerant is stored in liquid reservoir 14f. The liquid refrigerant can be stored up to height H of suction pipe inlet 14e. Therefore, the volume of liquid reservoir 14f is up to height H of suction pipe inlet 14e.

[0060] Compressor 1 is driven by an inverter at a plurality of operation frequencies, and is driven in a low rotation speed band in which the rotation speed of the electric motor unit 20 decreases or in a high rotation speed band in which the rotation speed of the electric motor unit 20 increases.

[0061] Compression chamber 34 illustrated in Fig. 3A is formed between upper bearing 51 and lower bearing 52 and between an inner peripheral surface of cylinder 31 and an outer peripheral surface of piston 32.

[0062] Suction pipe 12 is connected to suction passage 35 of compression mechanism unit 30.

[0063] Suction passage 35 is connected to compression chamber 34.

[0064] The rotation of shaft 40 causes piston 32 to revolve.

[0065] Vane 33 reciprocates in vane groove 36 by piston 32 revolving along an inner wall surface of cylinder 31. That is, vane groove 36 in which vane 33 is disposed is formed in cylinder 31.

[0066] Compression chamber 34 is partitioned by vane 33 into suction space 34a communicating with suction passage 35 and compression space 34b communicating with discharge hole 37. A suction volume formed in cylinder 31 is a volume of suction space 34a in a state where suction passage 35 is closed by piston 32, and is a volume in a state where suction space 34a becomes the maximum space.

[0067] The gas refrigerant sucked into compression chamber 34 from suction pipe 12 through suction passage 35 by the revolution of piston 32 is compressed in compression chamber 34 and then discharged from discharge hole 37 into sound deadening chamber 54.

[0068] The refrigerant gas discharged into the sound deadening chamber 54 is discharged into sealed container 10, and is discharged from discharge pipe 13 into the outside of sealed container 10. The high pressure refrigerant gas discharged to the outside of sealed container 10 passes through condenser 2, decompressor 3, and evaporator 4, becomes a low pressure refrigerant gas, and is returned to compression mechanism unit 30 via accumulator 14.

[0069] As illustrated in Fig. 3B, cylindrical groove 32a having an arc angle exceeding 180° is formed on the outer peripheral surface of piston 32. Cylindrical groove 32a extends from one end face to the other end face of piston 32.

[0070] Vane 33 includes vane side surface portion 33a that slides with vane groove 36, cylindrical portion 33b disposed in cylindrical groove 32a, and constricted portion 33c that connects vane side surface portion 33a and cylindrical portion 33b. Cylindrical portion 33b is formed at an end portion of vane 33.

[0071] By engaging cylindrical portion 33b with cylindrical groove 32a, vane 33 operates without being separated from piston 32. Note that piston 32 and vane 33 may be integrally formed.

[0072] Fig. 4 is a flowchart illustrating refrigerant flow channel switching control of refrigeration cycle device 100 according to the present example.

[0073] When the operation mode is a heating operation mode (step S1), controller 80 connects fifth refrigerant pipe 5e and refrigerant suction pipe 5f by refrigerant flow channel switching valve 8, and causes the refrigerant from fifth refrigerant pipe 5e to flow to refrigerant suction pipe 5f (step S2).

[0074] If the degree of superheating estimated from the suction refrigerant temperature or the discharge refrigerant temperature detected by detector 70 is greater than or equal to a threshold (No in step S3), the refrigerant flows through refrigerant suction pipe 5f without switching refrigerant flow channel switching valve 8 (step S2). Note that the estimation of the degree of superheating will be described later.

[0075] In a case where the degree of superheating estimated from the suction refrigerant temperature or the discharge refrigerant temperature detected by detector 70 is lower than the threshold (Yes in step S3), refrigerant flow channel switching valve 8 is switched (step S4), and the refrigerant from fifth refrigerant pipe 5e is caused to flow to heat exchange circuit 61 (step S5).

[0076] When defrosting is not required (No in step S6), the refrigerant from fifth refrigerant pipe 5e is caused to flow to heat exchange circuit 61 without switching refrigerant flow channel switching valve 8 (step S5).

[0077] Note that, in the present example, in a case where defrosting is not required (No in step S6), the refrigerant from fifth refrigerant pipe 5e is caused to flow to heat exchange circuit 61. However, although not illustrated in the drawing, in a case where defrosting is not required (No in step S6) and the degree of superheating estimated from the suction refrigerant temperature or the discharge refrigerant temperature detected by detector 70 is greater than or equal to the threshold, refrigerant flow channel switching valve 8 is switched to flow the refrigerant into refrigerant suction pipe 5f (step S2).

[0078] When detector 70 detects frost formation in heat source-side heat exchanger 4 and controller 80 determines that defrosting is required (Yes in step S6), the forward cycle defrosting operation or the reverse cycle defrosting operation is selected from the detected frost formation state.

[0079] In a case where the forward cycle defrosting operation mode is selected (Yes in step S7), controller 80 switches refrigerant flow channel switching valve 8 (step S8), and performs the defrosting operation with the refrigerant from fifth refrigerant pipe 5e flowing to heat exchange circuit 61 (step S9).

[0080] When the defrosting operation in the forward cycle defrosting operation mode is finished (Yes in step S10), the refrigerant flow channel switching valve 8 is switched (step S11), and the operation returns to an operation in the heating operation mode (step S1).

[0081] In a case where the reverse cycle defrosting operation mode is selected (No in step S7), controller 80 performs the defrosting operation with the refrigerant flowing through refrigerant suction pipe 5f without switching refrigerant flow channel switching valve 8 (step S12).

[0082] When the defrosting operation in the reverse cycle defrosting operation mode is finished (Yes in step S13), the operation returns to the operation in the heating operation mode (step S1).

[0083] As described above, refrigeration cycle device 100 causes the refrigerant to flow into refrigerant suction pipe 5f by refrigerant flow channel switching valve 8 when the degree of superheating estimated from the suction refrigerant temperature or the discharge refrigerant temperature detected by detector 70 is greater than or equal to the threshold in the heating operation mode. On the other hand, in a case where the degree of superheating is lower than the threshold, refrigeration cycle device 100 causes the refrigerant to flow to heat exchange circuit 61 by refrigerant flow channel switching valve 8. In this way, in a case where the degree of superheating is insufficient, for example, at a low external air temperature, at the time of starting the operation of compressor 1 or the like, the degree of superheating of the refrigerant sucked into compressor 1 can be sufficiently secured, vane 33 can be suppressed from being damaged by a load due to liquid compression, and a decrease in reliability of compressor 1 due to liquid compression can be suppressed.

[0084] Furthermore, refrigeration cycle device 100 causes the refrigerant to flow to refrigerant suction pipe 5f by refrigerant flow channel switching valve 8 in the heating operation mode, and causes the refrigerant to flow to heat exchange circuit 61 by refrigerant flow channel switching valve 8 in the forward cycle defrosting operation mode. In this way, even in the case of the forward cycle defrosting operation mode, the degree of superheating of the refrigerant sucked into compressor 1 can be sufficiently secured, vane 33 can be prevented from being damaged by the load due to liquid compression, a decrease in reliability of compressor 1 due to liquid compression can be suppressed, and defrosting performance at a low external temperature can be improved.

[0085] Fig. 5A is an explanatory diagram illustrating control of a degree of superheating or a high and low pressure difference of refrigeration cycle device 100 according to the present example. Fig. 5B is a diagram illustrating a relationship between the rotation speed band of compressor 1, and the target degree of superheating and the target high and low pressure difference range.

[0086] As illustrated in Fig. 5A, the degree of superheating (suction SH) can be estimated from, for example, a temperature difference between the suction temperature and the low pressure temperature, and the high and low pressure difference is a difference between hc and hd.

[0087] Controller 80 controls decompressor 3 so that the degree of superheating in a case where the rotation speed of compressor 1 is in the low rotation speed band is smaller than the degree of superheating in a case where the rotation speed is in the high rotation speed band.

[0088] Refrigeration cycle device 100 includes detector 70 that detects a suction refrigerant temperature of a refrigerant sucked into compressor 1 or a discharge refrigerant temperature of a refrigerant discharged from compressor 1. Controller 80 estimates the degree of superheating from the suction refrigerant temperature or the discharge refrigerant temperature detected by detector 70, and controls decompressor 3 so that the degree of superheating falls within a preset target degree of superheating range.

[0089] The target degree of superheating range is set according to the rotation speed band of compressor 1.

[0090] As illustrated in Fig. 5B, for example, in a case where the rotation speed band of compressor 1 is a maximum rotation speed band, a high rotation speed band, a medium rotation speed band, and a minimum rotation speed band, the target degree of superheating ranges corresponding to the respective rotation speed bands are set as follows. That is, the target degree of superheating range in the maximum rotation speed band is set to a range in which the target degree of superheating is maximized, and the target degree of superheating range in the high rotation speed band is set to a range in which the target degree of superheating is smaller than the maximum but larger than the medium. Furthermore, the target degree of superheating range in the medium rotation speed band is set to a range in which the target degree of superheating is smaller than large but larger than the minimum, and the target degree of superheating range in the minimum rotation speed band is set to a range in which the target degree of superheating is the minimum (zero). That is, controller 80 controls decompressor 3 with the degree of superheating set to zero in a case where the rotation speed band of compressor 1 is in the minimum rotation speed band.

[0091] Furthermore, controller 80 controls decompressor 3 such that a high and low pressure difference of the refrigerant before and after decompressor 3 in a case where the rotation speed of compressor 1 is in the low rotation speed band is smaller than the difference in a case where the rotation speed of compressor 1 is in the high rotation speed band.

[0092] Refrigeration cycle device 100 includes detector 70 that detects a high pressure side temperature or a high pressure side pressure of the refrigerant upstream of decompressor 3 and a low pressure side temperature or a low pressure side pressure of the refrigerant downstream of decompressor 3. Controller 80 controls decompressor 3 so that the high and low pressure difference of the refrigerant detected by detector 70 falls within a preset target high and low pressure difference range.

[0093] The target high and low pressure difference range is set according to the rotation speed band of compressor 1.

[0094] As illustrated in Fig. 5B, for example, in a case where the rotation speed band of compressor 1 is the maximum rotation speed band, the high rotation speed band, the medium rotation speed band, and the minimum rotation speed band, the target high and low pressure difference ranges corresponding to the respective rotation speed bands are set as follows. That is, the target high and low pressure difference range in the maximum rotation speed band is set to a range in which the high and low pressure difference is maximized, and the target high and low pressure difference range in the high rotation speed band is set to a range in which the high and low pressure difference is smaller than the maximum but larger than the medium. Furthermore, the high and low pressure difference in the medium rotation speed band is set to a range in which the high and low pressure difference is smaller than large but larger than minimum, and the high and low pressure difference in the minimum rotation speed band is set to minimum. That is, in a case where the rotation speed of compressor 1 is in the minimum rotation speed band, controller 80 controls decompressor 3 with the high and low pressure difference minimized.

[0095] As described above, refrigeration cycle device 100 according to the present example is a refrigeration cycle device in which compressor 1, utilization-side heat exchanger 2, decompressor 3, heat source-side heat exchanger 4, and four-way valve 7 are annularly connected by refrigerant pipe 5. Compressor 1 includes electric motor unit 20 and compression mechanism unit 30 in sealed container 10. Electric motor unit 20 and compression mechanism unit 30 are coupled by shaft 40. Compression mechanism unit 30 includes cylinder 31, piston 32 disposed in cylinder 31, and vane 33 that partitions the inside of cylinder 31. Shaft 40 includes eccentric portion 42. In refrigeration cycle device 100, vane groove 36 in which vane 33 is disposed is formed in cylinder 31. Eccentric portion 42 is disposed in cylinder 31. Piston 32 is fitted to eccentric portion 42. Vane 33 operates without being separated from piston 32. In refrigeration cycle device 100, refrigerant pipe 5 is provided with receiver 6 that stores a part of the refrigerant flowing through refrigerant pipe 5, and the receiver internal volume of receiver 6 is made larger than the difference between the utilization-side internal volume of heat exchange of utilization-side heat exchanger 2 and the heat source-side internal volume of heat exchange of the heat source-side heat exchanger 4 to reduce the liquid refrigerant sucked into cylinder 31. According to the present example, since vane 33 operates without being separated from piston 32, leakage of the refrigerant from the high pressure side to the low pressure side of compression chamber 34 can be prevented. Furthermore, according to the present example, receiver 6 that stores a part of the refrigerant flowing through refrigerant pipe 5 is provided in refrigerant pipe 5, so that the refrigerant can be stored in receiver 6 in a case where the refrigerant is excessive. Therefore, for example, even at the time of a low external air temperature or at the time of starting the operation of compressor 1, the degree of superheating of the refrigerant sucked into compressor 1 can be sufficiently secured, vane 33 can be suppressed from being damaged by a load due to liquid compression, and a decrease in reliability of compressor 1 due to liquid compression can be suppressed. In other words, refrigeration cycle device 100 according to the present example can prevent leakage of the refrigerant from the high pressure side to the low pressure side of compression chamber 34 and suppress liquid compression.

[0096] Furthermore, in refrigeration cycle device 100 according to the present example, receiver 6 is a sealed container, and a refrigerant introduction pipe that introduces the refrigerant into receiver 6 and a refrigerant derivation pipe that derives the refrigerant from receiver 6 are inserted vertically upward from the lower side of the container. As a result, the liquid refrigerant in the container does not flow out of the refrigerant derivation pipe due to inertia, the inflow of the liquid refrigerant into compressor 1 can be suppressed, and a decrease in reliability of compressor 1 due to liquid return can be suppressed.

[0097] Furthermore, in refrigeration cycle device 100 according to the present example, receiver 6 is provided in refrigerant pipe 5 between utilization-side heat exchanger 2 and decompressor 3, and the heat source-side internal volume of heat exchange is made larger than the utilization-side internal volume of heat exchange. In a case where the utilization-side heat exchanger 2 operates as a condenser, if the utilization-side internal volume of heat exchange is smaller than the heat source-side internal volume of heat exchange, the refrigerant circulation amount becomes excessive. However, according to the present example, by providing receiver 6 in refrigerant pipe 5 between utilization-side heat exchanger 2 and decompressor 3, the liquid refrigerant can be stored in receiver 6. Therefore, the degree of superheating of the refrigerant sucked into compressor 1 can be secured more reliably, and a decrease in reliability of compressor 1 due to liquid return can be suppressed.

[0098] Furthermore, in refrigeration cycle device 100 according to the present example, receiver 6 is a sealed container. In the refrigeration cycle device 100, utilization heat exchange-side connection refrigerant pipe 5c1 connected to utilization-side heat exchanger 2 and decompressor-side connection refrigerant pipe 5c2 connected to decompressor 3 are inserted vertically upward from the lower side of the container. In refrigeration cycle device 100, the opening end portion of decompressor-side connection refrigerant pipe 5c2 is located higher than the opening end portion of utilization heat exchange-side connection refrigerant pipe 5c1. As described above, in refrigeration cycle device 100, utilization heat exchange-side connection refrigerant pipe 5c1 and decompressor-side connection refrigerant pipe 5c2 are inserted vertically upward from the lower side of the container, and further, the opening end portion of decompressor-side connection refrigerant pipe 5c2 is located higher than the opening end portion of utilization heat exchange-side connection refrigerant pipe 5c1. As a result, the liquid refrigerant supplied from utilization-side heat exchanger 2 does not directly flow out to decompressor 3, and the degree of superheating of the refrigerant sucked into compressor 1 can be more reliably secured, so that a decrease in reliability of compressor 1 due to liquid return can be suppressed.

[0099] Furthermore, in refrigeration cycle device 100 according to the present example, receiver 6 is provided in fourth refrigerant pipe 5d between heat source-side heat exchanger 4 and decompressor 3, and the utilization-side internal volume of heat exchange is made larger than the heat source-side internal volume of heat exchange. In a case where heat source-side heat exchanger 4 operates as a condenser, if the heat source-side internal volume of heat exchange is smaller than the utilization-side internal volume of heat exchange, the refrigerant circulation amount becomes excessive. However, according to the present example, by providing receiver 6 in fourth refrigerant pipe 5d between heat source-side heat exchanger 4 and decompressor 3, the liquid refrigerant can be stored in receiver 6. Therefore, the degree of superheating of the refrigerant sucked into compressor 1 can be secured more reliably, and a decrease in reliability of compressor 1 due to liquid return can be suppressed.

[0100] Furthermore, in refrigeration cycle device 100 according to the present example, receiver 6 is a sealed container. In refrigeration cycle device 100, the heat source heat exchange-side connection refrigerant pipe connected to heat source-side heat exchanger 4 and decompressor-side connection refrigerant pipe 5c2 connected to decompressor 3 are inserted vertically upward from the lower side of the container. In refrigeration cycle device 100, the opening end portion of decompressor-side connection refrigerant pipe 5c2 is located higher than the opening end portion of the heat source heat exchange-side connection refrigerant pipe. As described above, in refrigeration cycle device 100, the heat source heat exchange-side connection refrigerant pipe and decompressor-side connection refrigerant pipe 5c2 are inserted vertically upward from the lower side of the container, and further, the opening end portion of decompressor-side connection refrigerant pipe 5c2 is located higher than the opening end portion of the heat source heat exchange-side connection refrigerant pipe. This prevents the liquid refrigerant supplied from heat source-side heat exchanger 4 from directly flowing out to decompressor 3. Therefore, the degree of superheating of the refrigerant sucked into compressor 1 can be secured more reliably, and a decrease in reliability of compressor 1 due to liquid return can be suppressed.

[0101] Furthermore, in refrigeration cycle device 100 according to the present example, compressor 1 includes electric motor unit 20 and compression mechanism unit 30 in sealed container 10. Electric motor unit 20 and compression mechanism unit 30 are coupled by shaft 40. Compression mechanism unit 30 includes cylinder 31, piston 32 disposed in cylinder 31, and vane 33 that partitions the inside of cylinder 31. Shaft 40 includes eccentric portion 42. In refrigeration cycle device 100, vane groove 36 in which vane 33 is disposed is formed in cylinder 31. Eccentric portion 42 is disposed in cylinder 31. Piston 32 is fitted to eccentric portion 42. Vane 33 operates without being separated from piston 32. Refrigeration cycle device 100 includes heat storage tank 60 using compressor 1 as a heat source. In refrigeration cycle device 100, refrigerant flow channel switching valve 8 is provided in refrigerant pipe 5 located upstream of suction pipe 12 of compressor 1. Refrigerant flow channel switching valve 8 switches between heat exchange circuit 61 that performs heat exchange in heat storage tank 60 and guides the refrigerant to suction pipe 12, and refrigerant suction pipe 5f that guides the refrigerant to suction pipe 12 without passing through heat exchange circuit 61. According to the present example, since vane 33 operates without being separated from piston 32, leakage of the refrigerant from the high pressure side to the low pressure side of compression chamber 34 can be prevented. Furthermore, according to the present example, by causing the refrigerant to flow through heat exchange circuit 61 that performs heat exchange in heat storage tank 60, the degree of superheating of the refrigerant sucked into compressor 1 can be sufficiently secured, vane 33 can be suppressed from being damaged by a load due to liquid compression, and a decrease in reliability of compressor 1 due to liquid compression can be suppressed.

[0102] Furthermore, refrigeration cycle device 100 according to the present example has the heating operation mode in which the refrigerant sequentially flows through compressor 1, utilization-side heat exchanger 2, decompressor 3, and heat source-side heat exchanger 4 to use utilization-side heat exchanger 2 as a condenser. Furthermore, refrigeration cycle device 100 has the forward cycle defrosting operation mode in which the refrigerant is caused to flow through compressor 1, utilization-side heat exchanger 2, decompressor 3, and heat source-side heat exchanger 4 in this order to defrost the heat source-side heat exchanger 4. Refrigeration cycle device 100 causes the refrigerant to flow to refrigerant suction pipe 5f by refrigerant flow channel switching valve 8 in the heating operation mode, and causes the refrigerant to flow to heat exchange circuit 61 by refrigerant flow channel switching valve 8 in the forward cycle defrosting operation mode. In this way, even in the case of the forward cycle defrosting operation mode, the degree of superheating of the refrigerant sucked into compressor 1 can be sufficiently secured, vane 33 can be prevented from being damaged by the load due to liquid compression, a decrease in reliability of compressor 1 due to liquid compression can be suppressed, and defrosting performance at a low external temperature can be improved.

[0103] Furthermore, in refrigeration cycle device 100 according to the present example, heat storage tank 60 includes a heat generating source such as a heater in addition to compressor 1 as a heat source. In this way, since the heating amount can be increased as necessary in addition to the exhaust heat of compressor 1, the degree of superheating of the refrigerant sucked into compressor 1 can be sufficiently secured.

[0104] Furthermore, in refrigeration cycle device 100 according to the present example, heat exchange circuit 61 includes an inner pipe through which the refrigerant passes, and has grooves or irregularities formed in at least one of the inner surface and the outer surface of the inner pipe. In this way, the heat transfer coefficient can be improved, the heat exchange from heat storage tank 60 to the refrigerant can be promoted, and the degree of superheating of the refrigerant sucked into compressor 1 can be sufficiently secured.

[0105] Furthermore, refrigeration cycle device 100 according to the present example includes detector 70 that detects a suction refrigerant temperature of a refrigerant sucked into compressor 1 or a discharge refrigerant temperature of a refrigerant discharged from compressor 1. Refrigeration cycle device 100 causes the refrigerant to flow as follows according to the degree of superheating estimated from the suction refrigerant temperature or the discharge refrigerant temperature detected by detector 70 in the heating operation mode in which utilization-side heat exchanger 2 is used as a condenser by causing the refrigerant to flow through compressor 1, utilization-side heat exchanger 2, decompressor 3, and heat source-side heat exchanger 4 in order. That is, refrigeration cycle device 100 causes the refrigerant to flow to refrigerant suction pipe 5f by refrigerant flow channel switching valve 8 in a case where the degree of superheating is greater than or equal to the threshold, and causes the refrigerant to flow to heat exchange circuit 61 by the refrigerant flow channel switching valve 8 in a case where the degree of superheating is less than the threshold. In this way, in a case where the degree of superheating is insufficient, for example, at a low external air temperature, at the time of starting the operation of compressor 1 or the like, the degree of superheating of the refrigerant sucked into compressor 1 can be sufficiently secured, vane 33 can be suppressed from being damaged by a load due to liquid compression, and a decrease in reliability of compressor 1 due to liquid compression can be suppressed.

[0106] Furthermore, refrigeration cycle device 100 according to the present example includes detector 70 that detects a suction refrigerant temperature of a refrigerant sucked into compressor 1 or a discharge refrigerant temperature of a refrigerant discharged from compressor 1. Furthermore, refrigeration cycle device 100 includes controller 80 that estimates a degree of superheating from a suction refrigerant temperature or a discharge refrigerant temperature detected by detector 70, and switches refrigerant flow channel switching valve 8 in accordance with the estimated degree of superheating. Controller 80 switches refrigerant flow channel switching valve 8 so that the refrigerant flows to refrigerant suction pipe 5f in a case where the estimated degree of superheating is greater than or equal to the threshold, and switches refrigerant flow channel switching valve 8 so that the refrigerant flows to heat exchange circuit 61 in a case where the degree of superheating is less than the threshold. In this way, in a case where the degree of superheating is insufficient, for example, at a low external air temperature, at the time of starting the operation of compressor 1 or the like, the degree of superheating of the refrigerant sucked into compressor 1 can be sufficiently secured, vane 33 can be suppressed from being damaged by a load due to liquid compression, and a decrease in reliability of compressor 1 due to liquid compression can be suppressed.

[0107] Furthermore, refrigeration cycle device 100 according to the present example is a refrigeration cycle device in which compressor 1, utilization-side heat exchanger 2, decompressor 3, and heat source-side heat exchanger 4 are annularly connected by refrigerant pipe 5, and the refrigeration cycle device includes controller 80 that controls a rotation speed of compressor 1 and a throttle amount of decompressor 3 to adjust a refrigerant circulation amount. Compressor 1 includes electric motor unit 20 and compression mechanism unit 30 in sealed container 10. Electric motor unit 20 and compression mechanism unit 30 are coupled by shaft 40. Compression mechanism unit 30 includes cylinder 31, piston 32 disposed in cylinder 31, and vane 33 that partitions the inside of cylinder 31. Shaft 40 includes eccentric portion 42. Vane groove 36 in which vane 33 is disposed is formed in cylinder 31. Eccentric portion 42 is disposed in cylinder 31. Piston 32 is fitted to eccentric portion 42. Vane 33 operates without being separated from piston 32. Controller 80 controls decompressor 3 so that the degree of superheating in a case where the rotation speed of compressor 1 is in the low rotation speed band is smaller than the degree of superheating in a case where the rotation speed is in the high rotation speed band. According to the present example, since vane 33 operates without being separated from piston 32, leakage of the refrigerant from the high pressure side to the low pressure side of compression chamber 34 can be prevented. Furthermore, according to the present example, in a case where the rotation speed of compressor 1 is in the low rotation speed band, an amount of liquid return decreases due to a decrease in a refrigerant circulation amount. Therefore, liquid compression can be suppressed even when the degree of superheating is reduced, and operation can be performed with high efficiency by reducing the degree of superheating.

[0108] Furthermore, refrigeration cycle device 100 according to the present example includes detector 70 that detects a suction refrigerant temperature of a refrigerant sucked into compressor 1 or a discharge refrigerant temperature of a refrigerant discharged from compressor 1. Controller 80 estimates the degree of superheating from the suction refrigerant temperature or the discharge refrigerant temperature detected by detector 70, and controls decompressor 3 so that the degree of superheating falls within a preset target degree of superheating range. As described above, by controlling the degree of superheating to fall within the target degree of superheating range, it is possible to suppress liquid compression and realize highly efficient operation.

[0109] Furthermore, in refrigeration cycle device 100 according to the present example, the target degree of superheating range is set according to the rotation speed band of compressor 1. As described above, by setting the target degree of superheating range according to the rotation speed band of compressor 1, it is possible to suppress liquid compression and realize highly efficient operation.

[0110] Furthermore, in refrigeration cycle device 100 according to the present example, controller 80 controls decompressor 3 with the degree of superheating set to zero in a case where the rotation speed of compressor 1 is in the minimum rotation speed band. As described above, when the degree of superheating is zero, the refrigerant is in a wet state and a liquid refrigerant is mixed. However, when the rotation speed of compressor 1 is in the minimum rotation speed band, the load due to liquid compression is small and vane 33 is not damaged. By setting the degree of superheating to zero, the compression ratio is reduced, so that operation can be performed with high efficiency.

[0111] Furthermore, refrigeration cycle device 100 according to the present example is a refrigeration cycle device in which compressor 1, utilization-side heat exchanger 2, decompressor 3, and heat source-side heat exchanger 4 are annularly connected by refrigerant pipe 5, and the refrigeration cycle device includes controller 80 that controls a rotation speed of compressor 1 and a throttle amount of decompressor 3 to adjust a refrigerant circulation amount. Compressor 1 includes electric motor unit 20 and compression mechanism unit 30 in sealed container 10. Electric motor unit 20 and compression mechanism unit 30 are coupled by shaft 40. Compression mechanism unit 30 includes cylinder 31, piston 32 disposed in cylinder 31, and vane 33 that partitions the inside of cylinder 31. Shaft 40 includes eccentric portion 42. Vane groove 36 in which vane 33 is disposed is formed in cylinder 31. Eccentric portion 42 is disposed in cylinder 31. Piston 32 is fitted to eccentric portion 42. Vane 33 operates without being separated from piston 32. Controller 80 controls decompressor 3 so as to reduce a high and low pressure difference of the refrigerant before and after decompressor 3 in a case where the rotation speed of compressor 1 is in the low rotation speed band as compared with the difference in a case where the rotation speed of compressor 1 is in the high rotation speed band. According to the present example, since vane 33 operates without being separated from piston 32, leakage of the refrigerant from the high pressure side to the low pressure side of compression chamber 34 can be prevented. Furthermore, according to the present example, in a case where the rotation speed of compressor 1 is in the low rotation speed band, an amount of liquid return decreases due to a decrease in a refrigerant circulation amount. Therefore, liquid compression can be suppressed even if a high and low pressure difference of the refrigerant before and after decompressor 3 is reduced, and the operation can be performed with high efficiency by reducing the high and low pressure difference of the refrigerant before and after decompressor 3. Furthermore, according to the present example, in a case where the rotation speed of compressor 1 is in the low rotation speed band, a compression load can be reduced by reducing the high and low pressure difference of the refrigerant before and after decompressor 3, and the stability of the compressor rotation can be secured.

[0112] Furthermore, refrigeration cycle device 100 according to the present example includes detector 70 that detects the high pressure side temperature or the high pressure side pressure of the refrigerant upstream of decompressor 3 and the low pressure side temperature or the low pressure side pressure of the refrigerant downstream of decompressor 3. Controller 80 controls the decompressor 3 so that the high and low pressure difference of the refrigerant detected by detector 70 falls within a preset target high and low pressure difference range. As described above, by controlling the high and low pressure difference to fall within the target high and low pressure difference range, it is possible to suppress liquid compression, perform highly efficient operation, and ensure stability of compressor rotation.

[0113] Furthermore, in refrigeration cycle device 100 according to the present example, the target high and low pressure difference range is set according to the rotation speed band of compressor 1. As described above, by setting the target high and low pressure difference range according to the rotation speed band of compressor 1, it is possible to suppress liquid compression, perform highly efficient operation, and ensure stability of compressor rotation.

[0114] Furthermore, in refrigeration cycle device 100 according to the present example, in a case where the rotation speed of compressor 1 is in the minimum rotation speed band, controller 80 controls decompressor 3 with the high and low pressure difference minimized. As described above, the high and low pressure difference of the refrigerant before and after decompressor 3 is reduced, so that the liquid refrigerant may be mixed. However, when the rotation speed of compressor 1 is in the minimum rotation speed band, the load due to the liquid compression is small, vane 33 is not damaged, and the high and low pressure difference of the refrigerant is small, so that the operation can be performed with high efficiency, and the stability of the compressor rotation can be secured.

[0115] The refrigeration cycle device of the present disclosure is applicable to, for example, a hot water heating device, an air conditioning device, a water heater, a refrigerator, a showcase, a chiller, a dehumidifier, or a freezing machine.

Examples

examples

[Examples]

[0015]Hereinafter, examples of the present disclosure will be described in detail with reference to the drawings. However, the drawings described in the following examples are schematic views, and the ratio of the size and the thickness of each component does not necessarily reflect the actual dimension ratio. Furthermore, the configurations described in the following examples are merely examples of the present disclosure. The present disclosure is not limited to the following examples, and various modifications can be made according to the design and the like as long as the effects of the present disclosure can be achieved. Note that "vertically upward" in the following examples means that it is intended to be vertically upward, but includes a portion slightly deviated from vertically upward due to an error or the like. Specifically, vertically upward means within 90° ± 5°, preferably within 90° ± 3°, and more preferably within 90° ± 1°.

[0016]Fig. 1 is a configuration dia...

Claims

1. A refrigeration cycle device comprising: a compressor; a utilization-side heat exchanger; a decompressor; a heat source-side heat exchanger; a four-way valve; and a refrigerant pipe annularly connecting the compressor, the utilization-side heat exchanger, the decompressor, the heat source-side heat exchanger, and the four-way valve, wherein the compressor includes a sealed container, an electric motor unit, a compression mechanism unit, and a shaft, the sealed container accommodating the electric motor unit and the compression mechanism unit, the electric motor unit and the compression mechanism unit are coupled by the shaft, the compression mechanism unit includes a cylinder, a piston disposed in the cylinder, and a vane that partitions an inside of the cylinder, the shaft includes an eccentric portion, the cylinder includes a vane groove formed in the cylinder, the vane being disposed in the vane groove, the eccentric portion is disposed in the cylinder, the piston is fitted to the eccentric portion, the vane operates without being separated from the piston, the refrigerant pipe includes, in the refrigerant pipe, a receiver that stores a part of a refrigerant flowing through the refrigerant pipe, and the receiver has a receiver internal volume that is made larger than a difference between a utilization-side internal volume of heat exchange of the utilization-side heat exchanger and a heat source-side internal volume of heat exchange of the heat source-side heat exchanger to reduce a liquid refrigerant sucked into the cylinder.

2. The refrigeration cycle device according to Claim 1, wherein the receiver includes a sealed container, and the receiver receives, vertically upward from a lower side of the sealed container, a refrigerant introduction pipe that introduces the refrigerant into the receiver and a refrigerant derivation pipe that derives the refrigerant from the receiver.

3. The refrigeration cycle device according to Claim 1, wherein the receiver is provided in the refrigerant pipe between the utilization-side heat exchanger and the decompressor, and the heat source-side internal volume of heat exchange is made larger than the utilization-side internal volume of heat exchange.

4. The refrigeration cycle device according to Claim 3, wherein the receiver includes a sealed container, and the receiver receives, vertically upward from a lower side of the sealed container, a utilization heat exchange-side connection refrigerant pipe connected to the utilization-side heat exchanger and a decompressor-side connection refrigerant pipe connected to the decompressor, and the decompressor-side connection refrigerant pipe includes an opening end portion located higher than an opening end portion of the utilization heat exchange-side connection refrigerant pipe.

5. The refrigeration cycle device according to Claim 1, wherein the receiver is provided in the refrigerant pipe between the heat source-side heat exchanger and the decompressor, and the utilization-side internal volume of heat exchange is made larger than the heat source-side internal volume of heat exchange.

6. The refrigeration cycle device according to Claim 5, wherein the receiver includes a sealed container, and the receiver receives, vertically upward from a lower side of the sealed container, a heat source heat exchange-side connection refrigerant pipe connected to the heat source-side heat exchanger and a decompressor-side connection refrigerant pipe connected to the decompressor, and the decompressor-side connection refrigerant pipe includes an opening end portion located higher than an opening end portion of the heat source heat exchange-side connection refrigerant pipe.

Images