US20120131949A1 - Fluid machine and refrigeration cycle apparatus - Google Patents
Fluid machine and refrigeration cycle apparatus Download PDFInfo
- Publication number
- US20120131949A1 US20120131949A1 US13/257,485 US201113257485A US2012131949A1 US 20120131949 A1 US20120131949 A1 US 20120131949A1 US 201113257485 A US201113257485 A US 201113257485A US 2012131949 A1 US2012131949 A1 US 2012131949A1
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- Prior art keywords
- compressor
- expander
- suction port
- working fluid
- shaft
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B11/00—Compression machines, plants or systems, using turbines, e.g. gas turbines
- F25B11/02—Compression machines, plants or systems, using turbines, e.g. gas turbines as expanders
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
- F01C1/00—Rotary-piston machines or engines
- F01C1/30—Rotary-piston machines or engines having the characteristics covered by two or more groups F01C1/02, F01C1/08, F01C1/22, F01C1/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members
- F01C1/34—Rotary-piston machines or engines having the characteristics covered by two or more groups F01C1/02, F01C1/08, F01C1/22, F01C1/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group F01C1/08 or F01C1/22 and relative reciprocation between the co-operating members
- F01C1/356—Rotary-piston machines or engines having the characteristics covered by two or more groups F01C1/02, F01C1/08, F01C1/22, F01C1/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group F01C1/08 or F01C1/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the outer member
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
- F01C13/00—Adaptations of machines or engines for special use; Combinations of engines with devices driven thereby
- F01C13/04—Adaptations of machines or engines for special use; Combinations of engines with devices driven thereby for driving pumps or compressors
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
- F04C18/30—Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups F04C18/02, F04C18/08, F04C18/22, F04C18/24, F04C18/48, or having the characteristics covered by one of these groups together with some other type of movement between co-operating members
- F04C18/34—Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups F04C18/02, F04C18/08, F04C18/22, F04C18/24, F04C18/48, or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group F04C18/08 or F04C18/22 and relative reciprocation between the co-operating members
- F04C18/356—Rotary-piston pumps specially adapted for elastic fluids having the characteristics covered by two or more of groups F04C18/02, F04C18/08, F04C18/22, F04C18/24, F04C18/48, or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in group F04C18/08 or F04C18/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the outer member
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C23/00—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids
- F04C23/001—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids of similar working principle
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C23/00—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids
- F04C23/02—Pumps characterised by combination with or adaptation to specific driving engines or motors
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
- F01C20/00—Control of, monitoring of, or safety arrangements for, machines or engines
- F01C20/24—Control of, monitoring of, or safety arrangements for, machines or engines characterised by using valves for controlling pressure or flow rate, e.g. discharge valves
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
- F25B2400/14—Power generation using energy from the expansion of the refrigerant
Definitions
- the present invention relates to a fluid machine used for water heaters, air-conditioners, etc, and a refrigeration cycle apparatus using the fluid machine.
- Patent Literature 1 discloses a fluid machine 100 shown in FIG. 12 .
- an expander 110 and a compressor 120 are coupled to each other by a shaft 101 in the fluid machine 100 . Both of the expander 110 and the compressor 120 are rotary type.
- the shaft 101 has a first eccentric portion 102 for the expander 110 and a second eccentric portion 103 for the compressor 120 .
- the expander 110 has an expander piston 112 into which the first eccentric portion 102 of the shaft 101 is fitted, and an expander cylinder 111 accommodating the expander piston 112 .
- a crescent-shaped expander working chamber 113 is formed between an inner circumferential surface of the expander cylinder 111 and an outer circumferential surface of the expander piston 112 .
- the expander working chamber 113 is partitioned into a suction side space and a discharge side space by an expander partition member 114 .
- the expander partition member 114 is integrated with the expander piston 112 .
- a columnar shoe 117 supporting reciprocably the expander partition member 114 is provided rotatably to the expander cylinder 111 . That is, the expander piston 112 swings taking the center of the shoe 117 as the pivot point while changing the distance between the supporting point and itself.
- the expander cylinder 111 is provided with a suction port 110 a through which a working fluid is introduced into the expander working chamber 113 , and a discharge port 110 b through which the working fluid is discharged from the expander working chamber 113 .
- the suction port 110 a is, at a specified timing, brought into communication with the expander working chamber 113 through a communication port 115 formed in the shoe 117 and a communication groove 116 formed in the expander partition member 113 . That is, the shoe 117 and the expander partition member 113 constitute a drawing control mechanism for opening and closing the suction port 110 a as the shaft 101 rotates.
- the timing at which the suction port 110 a is opened is a period of time from when the expander piston 112 is at a top dead center at which it retracts the expander partition member 114 most until the expander piston 112 rotates about 140° from the top dead center.
- the compressor 120 has a compressor piston 122 , composed of roller bearings, into which the second eccentric portion 103 of the shaft 101 is fitted, and a compressor cylinder 121 accommodating the compressor piston 122 .
- a crescent-shaped compressor working chamber 123 is formed between an inner circumferential surface of the compressor cylinder 121 and an outer circumferential surface of the compressor piston 122 .
- the compressor working chamber 123 is partitioned into a suction side space and a discharge side space by a compressor partition member 124 .
- the compressor partition member 114 is pressed against the compressor piston 122 by a spring.
- the compressor cylinder 121 is provided with a suction port 120 a through which the working fluid is introduced into the compressor working chamber 123 .
- a closing member adjacent to the compressor cylinder 121 and the compressor piston 122 is provided with a discharge port 120 b through which the working fluid is discharged from the compressor working chamber 113 .
- the suction port 120 a opens on the inner circumferential surface of the compressor cylinder 121 .
- the suction port 120 a is closed by the compressor piston 122 only when a sliding point of the compressor piston 122 sliding on the inner circumferential surface of the compressor cylinder 121 is present on the suction port 120 a.
- Patent Literature 1 also discloses a refrigeration cycle apparatus 200 shown in FIG. 15 using the fluid machine 100 .
- the refrigeration cycle apparatus 200 has a configuration in which the compressor 120 of the fluid machine 100 increases preliminarily the pressure of the working fluid to be drawn into a main compressor 210 .
- the main compressor 210 , a radiator 220 , the expander 110 , an evaporator 230 , and the compressor 120 are connected in this order by a flow passage so as to constitute a working fluid circuit.
- the fluid machine 100 includes no driving means such as a motor, and is expected to self-start owing to the pressure of the working fluid in the refrigeration cycle apparatus 200 as shown in FIG. 15 . That is, starting the main compressor 210 allows the high pressure working fluid to flow into the suction side space of the expander working chamber 113 of the expander 110 . This causes a pressure difference between the suction side space and the discharge side space of the expander working chamber 113 , and this pressure difference applies a torque to the shaft 101 to start the fluid machine 100 .
- driving means such as a motor
- the inventors of the present invention arrived at, prior to the present invention, an idea of guiding, at the time of starting, the high pressure working fluid discharged from the main compressor also to the compressor of the fluid machine to apply a torque to the shaft also in the compressor. That is, a bypass passage that links a high pressure flow passage between the main compressor and the radiator or between the radiator and the expander to a low pressure passage between the evaporator and the compressor is provided so as to allow the high pressure working fluid to flow also into the suction side space of the compressor working chamber of the compressor at the time of starting. Thereby, a pressure difference is generated also between the suction side space and the discharge side space of the compressor working chamber. As a result, a torque can be applied to the shaft also in the compressor.
- the position of the expander partition member 114 and the position of the compressor partition member 124 coincide with each other in the axial direction of the shaft 101 , and an eccentric orientation of the first eccentric portion 102 is deviated 180° from an eccentric orientation of the second eccentric portion 103 .
- the suction port 120 a is in communication with the discharge port 120 b through the compressor working chamber 123 until the sliding point of the compressor piston 121 reaches the suction port 120 a after passing the discharge port 120 b.
- the working fluid can flow into the suction side space of the expander working chamber 113 in the expander 110 when the rotation angle of the shaft 101 is in the range from 0° to about 140°.
- the suction port 120 a of the compressor 120 is closed by the compressor piston 122 when the rotation angle of the shaft 101 is in the range from about 190° to about 200°, the working fluid can flow into the suction side space of the compressor working chamber 123 when the rotation angle of the shaft 101 is out of this range.
- both of the expander suction port 110 a and the compressor suction port 120 a are closed, and the torque for rotating the shaft 110 is generated neither in the expander 110 nor in the compressor 120 .
- the suction port 120 a is in communication with the discharge port 120 b through the compressor working chamber 123 as described above and the working fluid that has flowed into the compressor working chamber 123 through the suction port 120 a is discharged through the discharge port 120 b . Furthermore, the suction port 110 a of the expander 110 is closed during that time. Therefore, when the fluid machine 100 is stopped in the state where the rotation angle of the shaft is between about 180° and about 200°, the torque for rotating the shaft 101 owing to the pressure of the working fluid cannot be generated and the fluid machine 100 cannot self-start.
- the present invention is intended to provide a fluid machine that can self-start owing to the pressure of the working fluid no matter in what state it is stopped, and a refrigeration cycle apparatus using the fluid machine.
- the present invention provides a fluid machine including: an expander that expands a working fluid drawn through an expander suction port and discharges the working fluid through an expander discharge port so as to recover power from the working fluid; a compressor that increases a pressure of the working fluid drawn through a compressor suction port and discharges the working fluid through a compressor discharge port; and a shaft that couples the expander to the compressor so that the compressor is driven by the power recovered by the expander.
- the expander suction port and the compressor suction port are opened and closed as the shaft rotates.
- the expander suction port is opened during a period of time when the compressor suction port is closed, and the compressor suction port is opened and maintained out of communication with the compressor discharge port during a period of time when the expander suction port is closed.
- the present invention also provides a refrigeration cycle apparatus using the fluid machine, including: a working fluid circuit through which a working fluid circulates, the working fluid circuit including a main compressor for compressing the working fluid, a radiator for radiating heat from the compressed working fluid, the expander for expanding the working fluid that has flowed out of the radiator, an evaporator for evaporating the expanded working fluid, and the compressor for increasing a pressure of the working fluid that has flowed out of the evaporator and supplying the working fluid to the main compressor; and a bypass passage linking a portion between the main compressor and the radiator or a portion between the radiator and the expander to a portion between the evaporator and the compressor in the working fluid circuit.
- the working fluid can always flow into one or both of the suction side space of the expander working chamber and the suction side space of the compressor working chamber.
- the working fluid that has flowed therein is prevented from being discharged through the compressor discharge port. Therefore, the fluid machine can self-start owing to the pressure of the working fluid no matter in what state it is stopped.
- FIG. 1 is a configuration diagram of a refrigeration cycle apparatus using a fluid machine according to Embodiment 1 of the present invention.
- FIG. 2 is a vertical cross-sectional view of the fluid machine according to Embodiment 1 of the present invention.
- FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2 .
- FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 2 .
- FIG. 5 is a cross-sectional view taken along the line V-V in FIG. 2 .
- FIGS. 6A to 6C each are a diagram illustrating the operating principle of the fluid machine according to Embodiment 1 of the present invention.
- FIGS. 7A to 7C each are a diagram illustrating the operating principle of the fluid machine according to Embodiment 1 of the present invention.
- FIG. 8 is a vertical cross-sectional view of a fluid machine according to Embodiment 2 of the present invention.
- FIG. 9 is a cross-sectional view taken along the line IX-IX in FIG. 8 .
- FIGS. 10A to 10C each are a diagram illustrating the operating principle of the fluid machine according to Embodiment 2 of the present invention.
- FIGS. 11A to 11C each are a diagram illustrating the operating principle of the fluid machine according to Embodiment 2 of the present invention.
- FIG. 12 is a vertical cross-sectional view of a conventional fluid machine.
- FIG. 13 is a cross-sectional view taken along the line A-A in FIG. 12 .
- FIG. 14 is a cross-sectional view taken along the line B-B in FIG. 12 .
- FIG. 15 is a configuration diagram of a refrigeration cycle using the fluid machine shown in FIG. 12 .
- FIG. 1 is a configuration diagram of a refrigeration cycle apparatus 1 using a fluid machine 8 A according to Embodiment 1 of the present invention.
- the refrigeration cycle apparatus 1 is provided with a working fluid circuit 7 through which a working fluid (refrigerant) circulates.
- the working fluid circuit 7 includes a main compressor 2 , a radiator 3 , an expander 4 , an evaporator 5 , and a compressor 6 as a sub compressor. These components 2 to 6 are connected in this order by a first to fifth flow passages (pipes) 7 a to 7 e .
- As the working fluid carbon dioxide and chlorofluorocarbon alternative can be used, for example.
- the main compressor 2 has, in a single closed casing 2 c holding a lubricating oil, a compression mechanism 2 a and a motor 2 b for driving the compression mechanism 2 a .
- the main compressor 2 compresses the working fluid at high temperature and high pressure.
- a scroll type compressor and a rotary type compressor can be used, for example.
- a discharge mouth of the main compressor 2 is connected to an inlet of the radiator 3 through the first flow passage 7 a.
- the radiator 3 radiates heat from the high temperature, high pressure working fluid compressed in the main compressor 2 to cool the working fluid.
- An outlet of the radiator 3 is connected to a suction mouth of the expander 4 through the second flow passage 7 b.
- the expander 4 expands the middle temperature, high pressure working fluid that has flowed out of the radiator 3 and converts the expansion energy of the working fluid into mechanical energy, thereby recovering power from the working fluid.
- the expander 4 is a rotary type expander (details will be described later).
- a discharge mouth of the expander 4 is connected to an inlet of the evaporator 5 through the third flow passage 7 c.
- the evaporator 5 heats the low temperature, low pressure working fluid that has been expanded in the expander 4 to evaporate the working fluid.
- An outlet of the evaporator 5 is connected to a suction mouth of the compressor 6 through the fourth flow passage 7 d.
- the compressor 6 increases preliminary the pressure of the middle temperature, low pressure working fluid that has flowed out of the evaporator 5 and supplies the working fluid to the main compressor 2 .
- the compressor 6 is a rotary type compressor (details will be described later).
- a discharge mouth of the compressor 6 is connected to a suction mouth of the main compressor 2 through the fifth flow passage 7 e.
- the expander 4 and the compressor 6 are disposed in a single closed casing 80 holding a lubricating oil, while being coupled to each other by a shaft 81 , to constitute the fluid machine 8 A. That is, the power recovered by the expander 4 is transferred to the compressor 6 via the shaft 81 , thereby driving the compressor 6 .
- the refrigeration cycle apparatus 1 shown in FIG. 1 further is provided with a first bypass passage 91 with its both ends being connected to the working fluid circuit 7 so as to bypass the evaporator 5 and the compressor 6 , and a second bypass passage (corresponding to a bypass passage of the present invention) 93 with its both ends being connected to the working fluid circuit 7 so as to bypass the expander 4 and the evaporator 5 .
- the first bypass passage 91 has a first bypass valve 92 for controlling the flow of the working fluid in the first bypass passage 91 .
- the second bypass passage 93 has a second bypass valve 94 for controlling the flow of the working fluid in the second bypass passage 93 .
- the first bypass passage 91 links the third flow passage 7 c for guiding the working fluid from the discharge mouth of the expander 4 to the inlet of the evaporator 5 to the fifth flow passage 7 e for guiding the working fluid from the discharge mouth of the compressor 6 to the suction mouth of the main compressor 2 .
- the first bypass passage 91 is a flow passage that allows the working fluid discharged from the expander 4 to bypass the evaporator 5 and the compressor 6 so as to be drawn directly into the main compressor 2 .
- a check valve is used as the first bypass valve 92 .
- the first bypass valve 92 is not limited to this, and an opening and closing valve or a three-way valve may be used.
- the first bypass valve 92 allows the working fluid to flow through the first bypass passage 91 when the working fluid in the first bypass passage 91 downstream (outlet side) of the first bypass valve 92 has a lower pressure than that of the working fluid in the first bypass passage 91 upstream (inlet side) of the first bypass valve 92 . In the opposite case, the first bypass valve 92 prohibits the working fluid from flowing through the first bypass passage 91 .
- the working fluid flows from the third flow passage 7 c into the fifth flow passage 7 e through the first bypass passage 91 when the working fluid in the fifth flow passage 7 e between the discharge mouth of the compressor 6 and the suction mouth of the main compressor 2 has a lower pressure than that of the working fluid in the flow passage (the third flow passage 7 c , the evaporator 5 , and the fourth flow passage 7 d ) between the discharge mouth of the expander 4 and the suction mouth of the compressor 6 .
- the second bypass passage 93 links the second flow passage 7 b for guiding the working fluid from the outlet of the radiator 3 to the suction mouth of the expander 4 to the fourth flow passage 7 d for guiding the working fluid from the outlet of the evaporator 5 to the suction mouth of the compressor 6 .
- the second bypass passage 93 is a flow passage that allows the high pressure working fluid that has flowed out of the radiator 3 to bypass the expander 4 and the evaporator 5 so as to be drawn directly into the compressor 6 .
- an opening and closing valve is used as the second bypass valve 94 .
- the second bypass valve 94 is not limited to this, and a three-way valve may be used.
- the second bypass passage 92 has only to be a flow passage that allows the high pressure working fluid to be drawn directly into the compressor 6 .
- the second bypass passage 92 may link the first flow passage 7 a for guiding the working fluid from the discharge mouth of the main compressor 2 to the inlet of the radiator 3 to the fourth flow passage 7 d.
- the second bypass valve 94 is opened in the start control, and thereby the high pressure working fluid that has flowed out of the radiator 3 flows from the second flow passage 7 b into the fourth flow passage 7 d through the second bypass passage 93 .
- a compressor upstream valve 71 for controlling the flow of the working fluid in the fourth flow passage 7 d is provided to the fourth flow passage 7 d between the outlet of the evaporator 5 and the position at which a downstream end of the second bypass passage 93 is connected to the fourth flow passage 7 d .
- an opening and closing valve is used as the compressor upstream valve 71 .
- the compressor upstream valve 71 is closed in the start control so as to prevent the working fluid from flowing from the evaporator 5 into the compressor 6 and prevent the working fluid that has flowed into the fourth flow passage 7 d through the second bypass passage 93 from flowing into the evaporator 5 .
- the second bypass valve 94 and the compressor upstream valve 71 are controlled by a controller that is not shown.
- the refrigeration cycle apparatus 1 is provided, although not shown, with a start detection means for detecting that the compressor 6 is started. When the compressor 6 is started, a detection signal is transmitted from the start detection means to the controller.
- the start detection means it is possible to use a method, with a thermocouple provided to the third flow passage 7 c on a discharge side of the expander 4 , to measure the temperature of the working fluid in the third flow passage 7 c , for example.
- the refrigeration cycle apparatus 1 performs the start control first, and then initiates steady operation.
- the pressure of the working fluid in the working fluid circuit 7 is approximately uniform when the refrigeration cycle apparatus 1 is in standby state (stopped state) for operation.
- the second bypass valve 94 is opened and the compressor upstream valve 71 is closed first. Thereby, the second bypass passage 93 is opened through and the fourth flow passage 7 d is blocked between the outlet of the evaporator 5 and the downstream end of the second bypass passage 93 . Subsequently, the main compressor 2 is started and the working fluid in the fifth flow passage 7 e and the working fluid in the first bypass passage 91 downstream of the first bypass valve 92 are drawn into the main compressor 2 .
- the first bypass valve 92 which is a check valve, is opened, and the working fluid in the flow passage (the third flow passage 7 c , the evaporator 5 , and a part of the fourth flow passage 7 d ) from the discharge mouth of the expander 4 to the compressor upstream valve 71 flows into the first bypass passage 91 .
- the working fluid in the flow passage from the discharge mouth of the expander 4 to the compressor upstream valve 71 is drawn into the main compressor 2 together with the working fluid in the first bypass passage 9 and the working fluid in the fifth flow passage 7 e so as to be compressed and discharged into the first flow passage 7 a .
- the pressure of the working fluid in the first bypass passage 91 upstream of the first bypass valve 92 and the working fluid in the flow passage from the discharge mouth of the expander 4 to the compressor upstream valve 71 are lowered.
- the pressure of the working fluid in the flow passage (the first flow passage 7 a , the radiator 3 , and the second flow passage 7 b ) from the discharge mouth of the main compressor 2 to the suction mouth of the expander 4 is increased because the working fluid drawn into the main compressor 2 is compressed and discharged.
- the second bypass valve 94 is opened and the compressor upstream valve 71 is closed in the start control, the working fluid in the flow passage from the discharge mouth of the main compressor 2 to the suction mouth of the expander 4 flows, through the second bypass passage 93 , also into a portion of the fourth flow passage 7 d between the compressor upstream valve 71 and the suction mouth of the compressor 6 .
- the second bypass valve 94 When the above-mentioned start detection means detects that the compressor 6 is started, the second bypass valve 94 is closed and the compressor upstream valve 71 is opened. Thereby, the second bypass passage 93 is blocked and the fourth flow passage 7 d is opened through. Then the refrigeration cycle apparatus 1 ends the start control and shifts to the steady operation in which the working fluid circulates through the working fluid circuit 7 .
- the working fluid in the fourth flow passage 7 d and the working fluid in the second bypass passage 93 downstream of the second bypass valve 94 are drawn into the compressor 6 and its pressure is increased, and the working fluid is discharged into the fifth flow passage 7 e .
- the working fluid in the fifth flow passage 7 e and the working fluid in the first bypass passage 91 downstream of the first bypass valve 92 have a higher pressure than the pressure of the working fluid in the flow passage (the third flow passage 7 c , the evaporator 5 , and the fourth flow passage 7 d ) from the discharge mouth of the expander 4 to the suction mouth of the compressor 6 and the pressure of the working fluid in the first bypass passage 91 upstream of the first bypass valve 92 .
- the first bypass valve 92 which is a check valve, is closed.
- the working fluid in the fifth flow passage 7 e and the working fluid in the first bypass passage 91 downstream of the first bypass valve 92 have a high pressure as in the case above, and thus the first bypass valve 92 remains closed. Thereby, the working fluid during the steady operation circulates through the working fluid circuit 7 .
- FIG. 2 is a vertical cross-sectional view of the fluid machine 8 A.
- FIGS. 3 to 5 are transverse cross-sectional views of the fluid machine 8 A taken along the lines III-III to V-V in FIG. 2 , respectively.
- the closed casing 80 is omitted.
- the fluid machine 8 A is a power recovering system in which the expander 4 and the compressor 6 are coupled to each other by the shaft 81 so that the power recovered by the expander 4 drives the compressor 6 .
- the shaft 81 extends in a vertical direction
- the expander 4 is disposed at a lower part in the closed casing 80
- the compressor 6 is disposed at an upper part in the closed casing 80 .
- the positional relationship between the expander 4 and the compressor 6 may be vertically opposite.
- the shaft 81 may extend in a lateral direction so that the expander 4 and the compressor 6 are aligned in the lateral direction.
- the closed casing 80 is filled with the lubricating oil to an extent that the oil level is present above the compressor 6 .
- the shaft 81 has a first eccentric portion 81 b for the expander 4 and a second eccentric portion 81 c for the compressor 6 as eccentric portions, each having a central axis at a location away from the axial center of the shaft 81 .
- An oil supply passage 81 a that penetrates through the shaft 81 in the axial direction and that opens on an outer circumferential surface of the first eccentric portion 81 b , an outer circumferential surface of the second eccentric portion 81 c , etc. is formed in the shaft 81 .
- the oil supply passage 81 a Through the oil supply passage 81 a , the lubricating oil in the closed casing 80 is supplied to the sliding parts, etc. of the expander 4 and the compressor 6 .
- the expander 4 is a rotary type expander in the present embodiment.
- the expander 4 is not limited to the rotary type expander and may be a scroll type expander or another type of expander.
- the expander 4 expands the working fluid drawn through the expander suction port 4 a and discharges the working fluid through the expander discharge port 4 b so as to recover power from the working fluid.
- the expander 4 has an expander piston 42 into which the first eccentric portion 81 b of the shaft 81 is fitted, and an expander cylinder 41 accommodating the expander piston 42 .
- the expander cylinder 41 has an inner circumferential surface forming a cylindrical surface whose central axis coincides with the axial center of the shaft 81 .
- the expander piston 42 performs an eccentric rotational motion along the inner circumferential surface of the expander cylinder 41 as the shaft 81 rotates. That is, a crescent-shaped expander working chamber 43 is formed between the inner circumferential surface of the expander cylinder 41 and an outer circumferential surface of the expander piston 42 .
- the expander working chamber 43 is partitioned into a suction side space 43 a and a discharge side space 43 b by an expander partition member 44 .
- the expander suction port 4 a opens to a portion of the suction side space 43 a adjacent to the expander partition member 44 .
- the expander discharge port 4 b opens to a portion of the discharge side space 43 b adjacent to the expander partition member 44 .
- the expander partition member 44 has a plate-like shape and is inserted reciprocably in a groove 41 a formed in the expander cylinder 41 .
- the groove 41 a opens to the expander working chamber 43 , on a straight line passing the axial center of the shaft 81 .
- a biasing means 45 for pressing the expander partition member 44 against the outer circumferential surface of the expander piston 42 is disposed between a bottom of the groove 41 a and the expander partition member 44 .
- the biasing means 45 can be composed of a compression coil spring, for example.
- the biasing means 45 may be a so-called gas spring configured by making a back space between a rear edge of the expander partition member 44 and the bottom of the groove 41 a a closed space.
- the biasing means 45 may be composed of two or more types of springs, such as the compression coil spring and the gas spring, of course.
- the expander piston 42 and the expander partition member 44 may be integrated with each other, without the biasing means 45 being provided.
- the expander 4 has a first closing member (inner closing member) 49 for closing the expander working chamber 43 from a side of the compressor 6 , a second closing member (outer closing member) 46 for closing the expander working chamber 43 from a side opposite to the compressor 6 , and a bearing member 47 disposed below the second closing member 46 .
- the bearing member 47 is fixed to an inner circumferential surface of the closed casing 80 and supports rotatably a lower part of the shaft 81 .
- the second closing member 46 , the expander cylinder 41 , and the first closing member 49 are stacked in this order on the bearing member 47 .
- a suction pipe 82 and a discharge pipe 83 penetrating through the closed casing 80 are connected to the bearing member 47 .
- the first closing member 49 and the second closing member 46 each have a disc shape that is flattened in the axial direction of the shaft 81 .
- the shaft 81 penetrates through the centers of the first closing member 49 and the second closing member 46 .
- the expander suction port 4 a is provided in the second closing member 46 and the expander discharge port 4 b is provided in the first closing member 49 and the expander cylinder 41 .
- a circular recessed portion 46 a whose center coincides with the axial center of the shaft 81 is provided on a lower surface of the second closing member 46 .
- the expander suction port 4 a penetrates through the second closing member 46 in the axial direction of the shaft 81 so as to extend straightly from an upper surface of the second closing member 46 to a bottom surface of the recessed portion 46 a .
- the expander suction port 4 a is in communication with the suction pipe 82 through a suction space inside the recessed portion 46 a and a suction passage 47 a formed in the bearing member 47 . That is, the high pressure working fluid from the second flow passage 7 b shown in FIG. 1 is guided from the expander suction port 4 a to the suction side space 43 a of the expander working chamber 43 through the suction pipe 82 , the suction passage 47 a , and the suction space inside the recessed portion 46 a.
- the expander discharge port 4 b is constructed of a vertical groove 41 b recessed radially outward and formed in the inner circumferential surface of the expander cylinder 41 , and a lateral groove 49 a formed in a lower surface of the first closing member 49 so as to extend radially outward from a position corresponding to the vertical groove 41 b .
- An outer end of the expander discharge port 4 b is in communication with the discharge pipe 83 through a discharge passage 4 c formed so as to extend across the expander cylinder 41 , the second closing member 46 , and the bearing member 47 .
- the working fluid in the discharge side space 43 b of the expander working chamber 43 is discharged into the third flow passage 7 c shown in FIG. 1 through the expander discharge port 4 b , the discharge passage 4 c , and the discharge pipe 83 .
- a rotor plate 48 is disposed as a drawing control mechanism for opening and closing the expander suction port 4 a as the shaft 81 rotates.
- the rotor plate 48 is attached to the shaft 81 so as to rotate while being in contact with the bottom surface of the recessed portion 46 a.
- the expander suction port 4 a extends in an arc shape from a vicinity of the expander partition member 44 along the inner circumferential surface of the expander cylinder 41 .
- the rotor plate 48 has a large diameter portion 48 a for blocking the expander suction port 4 a and a small diameter portion 48 b for exposing the expander suction port 4 a.
- the expander suction port 4 a is exposed partly or completely when the expander piston 41 rotates 140° from a top dead center, and the expander suction port 4 a is completely blocked by the large diameter portion 48 a anytime other than this period, according to the angle ranges and positions of the large diameter portion 48 a and the small diameter portion 48 b .
- the top dead center refers to a location at which a sliding point of the expander piston 42 sliding on the inner circumferential surface of the expander cylinder 41 coincides with the expander partition member 44 .
- the configuration of the expander 4 can be inverted vertically. That is, the first closing member 49 , the expander cylinder 41 , the second closing member 46 , the rotor plate 48 , and the bearing member 47 may be disposed in this order from bottom to top so that the first closing member 49 serves as the outer closing member and the second closing member 46 serves as the inner closing member.
- the bearing member 47 may fit loosely around the shaft 81
- the first closing member 49 may have a function of supporting rotatably the lower part of the shaft 81 .
- the compressor 6 is a rotary type compressor in the present embodiment.
- the compressor 6 increases the pressure of the working fluid drawn through the compressor suction port 6 a and discharges the working fluid through the compressor discharge port 6 b.
- the compressor 6 has a compressor piston 62 into which the second eccentric portion 81 c of the shaft 81 is fitted, and a compressor cylinder 61 accommodating the compressor piston 62 .
- the compressor cylinder 61 has an inner circumferential surface forming a cylindrical surface whose central axis coincides with the axial center of the shaft 81 .
- the compressor piston 62 performs an eccentric rotational motion along the inner circumferential surface of the compressor cylinder 61 as the shaft 81 rotates. That is, a crescent-shaped compressor working chamber 63 is formed between the inner circumferential surface of the compressor cylinder 61 and an outer circumferential surfaces of the compressor piston 62 .
- the compressor working chamber 63 is partitioned into a suction side space 63 a and a discharge side space 63 b by an compressor partition member 64 .
- the compressor suction port 6 a opens to a portion of the suction side space 63 a adjacent to the compressor partition member 64 .
- the compressor discharge port 6 b opens to a portion of the discharge side space 63 b adjacent to the compressor partition member 64 .
- the compressor partition member 64 has a plate-like shape and is inserted reciprocably in a groove 61 a formed in the compressor cylinder 61 .
- the groove 61 a opens to the compressor working chamber 63 , on a straight line passing the axial center of the shaft 81 .
- a biasing means 65 for pressing the compressor partition member 64 against the outer circumferential surface of the compressor piston 62 is disposed between a bottom of the groove 61 a and the compressor partition member 64 .
- the biasing means 65 can be composed of a compression coil spring, for example.
- the biasing means 65 may be a so-called gas spring configured by making a back space between a rear edge of the compressor partition member 64 and the bottom of the groove 61 a a closed space.
- the biasing means 65 may be composed of two or more types of springs, such as the compression coil spring and the gas spring, of course.
- the compressor piston 62 and the compressor partition member 64 may be integrated with each other, without the biasing means 65 being provided.
- the compressor 6 has the first closing member (inner closing member) 49 for closing the compressor working chamber 63 from a side of the expander 4 , a second closing member (outer closing member) 66 for closing the compressor working chamber 63 from a side opposite to the expander 4 , and a cover member 67 disposed above the second closing member 46 . That is, the expander 4 and the compressor 6 share the first closing member 49 in the present embodiment. However, the expander 4 and the compressor 6 may have the first closing members, respectively.
- the second closing member 66 has a function as a bearing member for supporting rotatably an upper part of the shaft 81 .
- the compressor cylinder 61 , the second closing member 66 , and the cover member 67 are stacked in this order on the first closing member 49 .
- a suction pipe 84 penetrating through the closed casing 80 is connected to the compressor cylinder 61 .
- a discharge pipe 85 penetrating through the closed casing 80 is connected to the second closing member 66 .
- the second closing member 66 has a disc shape that is flattened in the axial direction of the shaft 81 .
- the shaft 81 penetrates through the center of the second closing member 66 .
- the cover member 67 also has a disc shape that is flattened in the axial direction of the shaft 81 .
- an opening through which an upper end portion of the shaft 81 is exposed is provided.
- the compressor suction port 6 a is provided in the compressor cylinder 61 and the compressor discharge port 6 b is provided in the second closing member 66 .
- the compressor suction port 6 a penetrates laterally through the compressor cylinder 61 .
- the compressor suction port 6 a opens approximately circularly on the inner circumferential surface of the compressor cylinder 61 , and is in communication with the suction pipe 84 . That is, the low pressure (high pressure during the start control) working fluid from the fourth flow passage 7 d shown in FIG. 1 is guided from the compressor suction port 6 a to the suction side space 63 a of the compressor working chamber 63 through the suction pipe 84 .
- the compressor suction port 6 a Since the compressor suction port 6 a opens on the inner circumferential surface of the compressor cylinder 61 , it is opened and closed by the compressor piston 62 as the shaft rotates. More specifically, the compressor suction port 6 a is closed by the compressor piston 62 only when the sliding point of the compressor piston 62 sliding on the inner circumferential surface of the compressor cylinder 61 is present on the compressor suction port 6 a , in other words, only when the compressor piston 62 rotates from the point of about 5° to the point of about 15°, with a top dead center (a location at which the sliding point of the compressor piston 62 coincides with the compressor partition member 64 ) being defined as 0°.
- the compressor suction port 6 a is not completely closed by the compressor piston 62 because the inner circumferential surface of the compressor cylinder 61 and the outer circumferential surface of the compressor piston 62 have different diameters from each other. However, in this description, it is defined, as described above, that the compressor suction port 6 a is closed when the sliding point of the compressor piston 62 is present on the compressor suction port 6 a.
- a discharge chamber 66 a opening upward and closed by the cover member 67 , and a discharge passage 66 b extending from the discharge chamber 66 a to the discharge pipe 85 are formed in the second closing member 66 .
- the compressor discharge port 6 b has a circular section and penetrates through the second closing member 66 in the axial direction of the shaft 81 so as to extend straightly from a lower surface of the second closing member 66 to the discharge chamber 66 a .
- the compressor discharge port 6 b is in communication with the discharge pipe 85 through the discharge chamber 66 a and the discharge passage 66 b . That is, the working fluid in the discharge side space 63 b of the compressor working chamber 63 is discharged into the fifth flow passage 7 e shown in FIG. 1 through the compressor discharge port 6 b , the discharge chamber 66 a , the discharge passage 66 b , and the discharge pipe 85 .
- the compressor discharge port 6 b is disposed at a location that allows it to be crossed by the inner circumferential surface of the compressor cylinder 61 , the compressor discharge port 6 b is closed by the compressor piston 62 only when the sliding point of the compressor piston 62 is present on the compressor discharge port 6 b , in other words, only when the compressor piston 62 rotates from the point of about 345° to the point of about 355°, with the top dead center being defined as 0°.
- the compressor discharge port 6 b is not completely closed by the compressor piston 62 in a strict sense. However, in this description, it is defined, as described above, that the compressor discharge port 6 b is closed when the sliding point of the compressor piston 62 is present on the compressor discharge port 6 b.
- a discharge valve 68 that, by being deformed elastically, opens and closes automatically the compressor discharge port 6 b owing to the pressure of the discharge side space 63 b of the compressor working chamber 63 is disposed in the discharge chamber 66 a.
- Forming the compressor suction port 6 a as described above makes it possible to reduce the passage resistance of the working fluid flowing into the compressor working chamber 63 and suppress the decrease in the pressure of the working fluid to be drawn into the compressor 6 .
- forming the compressor discharge port 6 b as described above makes it possible to simplify the structure of the compressor 6 , reduce the passage resistance of the working fluid flowing out of the compressor working chamber 63 , and suppress the decrease in the pressure of the working fluid to be discharged from the compressor 6 .
- the configuration of the compressor 6 can be inverted vertically. That is, the cover member 67 , the second closing member 66 , the compressor cylinder 61 , and the first closing member 49 may be disposed in this order from bottom to top so that the first closing member 49 serves as the outer closing member and the second closing member 66 serves as the inner closing member.
- the second closing member 66 may fit loosely around the shaft 81
- the first closing member 49 may have a function of supporting rotatably the upper part of the shaft 81 .
- the fluid machine 8 A is configured so that the expander suction port 6 a is opened during a period of time when the compressor suction port 6 a is closed, and the compressor suction port 6 a is opened and maintained out of communication with the compressor discharge port 6 b during a period of time when the expander suction port 6 a is closed.
- the shaft 81 , the expander 4 , and the compressor 6 are configured so that the compressor piston 62 passes the top dead center within a period of time when the expander suction port 6 a is opened.
- Formula 1 below preferably is satisfied where, when a rotation direction of the shaft 81 is defined as positive, ⁇ c ( ⁇ 180° ⁇ c ⁇ 180°) indicates a phase difference of an eccentric orientation of the second eccentric portion 81 c with respect to an eccentric orientation of the first eccentric portion 81 b , ⁇ v ( ⁇ 180° ⁇ c ⁇ 180°) indicates a phase difference of a position of the compressor partition member 64 with respect to a position of the expander partition member 44 , and further ⁇ o indicates a rotation angle of the shaft during the period of time when the expander suction port 6 a is opened.
- the present invention is not limited to this.
- it may be configured so that the first eccentric portion 81 b and the second eccentric portion 81 c are eccentric in the same direction and the position of the expander partition member 44 and the position of the compressor partition member 64 are deviated from each other within a range that satisfies Formula 1, or so that deviations occur in terms both of the eccentric orientation and the position of the partition members within ranges that satisfy Formula 1.
- the rotation angle ⁇ of the shaft 81 when the expander piston 42 is present at the top dead center is defined as 0°.
- the expander suction port 4 a starts being blocked by the rotor plate 48 when the shaft 81 rotates about 125°, and the expander suction port 4 a is blocked completely when the shaft 81 rotates about 140°. Thereby, the suction process is completed.
- the volumetric capacity of the suction side space 63 a of the expander working chamber 63 increases gradually as the shaft 81 rotates, and thereby the working fluid is expanded and a torque is applied to the shaft 81 .
- the torque applied to the shaft 81 is used as the power for the compressor 6 .
- the shaft 81 rotates 360° and the expander piston 42 passes the top dead center, so that the suction side space 43 a of the expander working chamber 43 shifts to the discharge side space 43 b .
- the shaft 81 makes one rotation, so that the expanded working fluid is discharged from the discharge side space 63 b toward the evaporator 5 through the expander discharge port 4 b.
- the shaft 81 is rotated by the power recovered by the expander 4 . With the rotation of the shaft 81 , the compressor piston 62 also rotates, and thereby the compressor 6 is driven.
- the compressor suction port 6 a is opened when the shaft 81 rotates about 105°, and the low pressure working fluid from the evaporator 5 is drawn into the suction side space 63 a of the compressor working chamber 63 through the compressor suction port 6 a . Then, the compressor piston 62 rotates further and the suction side space 63 a of the compressor working chamber 63 is brought into communication with the compressor discharge port 6 b , and thereafter the compressor piston 62 passes the top dead center.
- the suction side space 63 a of the compressor working chamber 63 shifts to the discharge side space 63 b , so that the volumetric capacity of the discharge side space 63 b of the compressor working chamber 63 decreases gradually as the shaft 81 rotates.
- the working fluid in the discharge side space 63 b of the compressor working chamber 63 presses and opens the discharge valve 68 and is discharged toward the main compressor 2 through the compressor discharge port 6 b.
- the expander suction port 4 a is closed after the compressor suction port 6 a is brought into communication with the suction side space 63 a of the compressor working chamber 63 , and the expander suction port 4 a is opened before the suction side space 63 a of the compressor working chamber 63 is brought into communication with the compressor discharge port 6 b.
- the flow passage of the fluid machine 8 A upstream of the expander suction port 4 a through the suction pipe 82 and the flow passage of the fluid machine 8 A upstream of the compressor suction port 6 a through the suction pipe 84 are filled with the high pressure working fluid.
- the fluid machine 8 A since the fluid machine 8 A is configured as described above, at least one of the expander suction port 4 a and the compressor suction port 6 a always is opened and the high pressure working fluid always flows into at least one of the suction side space 43 a of the expander working chamber 43 and the suction side space 63 a of the compressor working chamber 63 no matter what angular position the shaft 81 of the fluid machine 8 A takes at the start of the refrigeration cycle apparatus. Moreover, it is after the expander suction port 4 a is opened that the compressor suction port 6 a is brought into communication with the compressor discharge port 63 b through the compressor working chamber 63 .
- both of the expander suction port 4 a and the compressor suction port 6 a are opened and the high pressure working fluid flows into the suction side space 43 a of the expander working chamber 43 and the suction side space 63 a of the compressor working chamber 63 .
- a torque is generated in each of the expander 4 and the compressor 6 .
- both of the expander suction port 4 a and the compressor suction port 6 a are opened and the high pressure working fluid flows into the suction side space 43 a of the expander working chamber 43 and the suction side space 63 a of the compressor working chamber 63 .
- a torque is generated in each of the expander 4 and the compressor 6 .
- the fluid machine 8 A which has no driving device, can self-start without fail at the start of the refrigeration cycle apparatus 1 owing only to the pressure of the working fluid. Therefore, the reliability of the refrigeration cycle apparatus 1 can be increased.
- Embodiment 2 of the present invention a fluid machine 8 B according to Embodiment 2 of the present invention will be described with reference to FIG. 8 and FIG. 9 .
- the same components as those in Embodiment 1 are designated by the same reference numerals, and the descriptions thereof are omitted.
- a refrigeration cycle apparatus using the fluid machine 8 B is the same as the refrigeration cycle apparatus 1 shown in FIG. 1 , the description thereof also is omitted.
- the fluid machine 8 B of the present embodiment is different from the fluid machine 8 A of Embodiment 1 in that the suction pipe 84 is connected to the second closing member 66 , and the compressor 6 is a fluid pressure motor compressor and does not have the discharge valve 68 (see FIG. 2 ). That is, the compressor 6 increases the pressure of the working fluid without changing the volume of the working fluid.
- the compressor suction port 6 a is provided so as to be exposed only to the suction side space 63 a of the compressor working chamber 63 and the compressor discharge port 6 b is provided so as to be exposed only to the discharge side space 63 b of the compressor working chamber 63 .
- Both of the compressor suction port 6 a and the compressor discharge port 6 b extend in the axial direction of the shaft 81 .
- a suction passage 6 c that brings an upper end of the compressor suction port 6 a into communication with the suction pipe 84 and a discharge passage 6 d that brings an upper end of the compressor discharge port 6 b into communication with the discharge pipe 85 are formed in the second closing member 66 .
- the compressor suction port 6 a and the compressor discharge port 6 b extend from a vicinity of the compressor partition member 64 so as to be gradually away from the inner circumferential surface of the compressor cylinder 61 .
- Outer edges of the compressor suction port 6 a and the compressor discharge port 6 b (edges on a side of the inner circumferential surface of the compressor cylinder 61 ) each are formed in an arc shape that coincides with the outer circumferential surface of the compressor piston 62 when the compressor piston 62 is present at the top dead center.
- the compressor suction port 6 a is completely closed by the compressor piston 63 only during a short period of time after the compressor piston 62 is present at the top dead center
- the compressor discharge port 6 b is completely closed by the compressor piston 63 only during a short period of time before the compressor piston 62 is present at the top dead center.
- the relationship between the eccentric orientation of the first eccentric portion 81 b of the shaft 81 and the eccentric orientation of the second eccentric portion 82 b of the shaft 81 , and the relationship between the position of the expander partition member 44 and the position of the compressor partition member 64 are the same as in Embodiment 1.
- the compressor suction port 6 a and the compressor discharge port 6 b do not necessarily have to be provided in the second closing member 66 , and one or both of them may be provided in the first closing member 49 .
- FIGS. 10A to 10C and FIGS. 11A to 11C the rotation angle ⁇ of the shaft 81 when the expander piston 42 is present at the top dead center is defined as 0°. Since the operation of the expander 4 is the same as in Embodiment 1, the description thereof is omitted.
- the compressor suction port 6 a is completely closed by the compressor piston 62 when the shaft 81 rotates from the point of 90° to the point of about 95°. After the shaft 81 rotates about 95°, the compressor suction port 6 a is opened gradually and the low pressure working fluid from the evaporator 5 is drawn into the suction side space 63 a of the compressor working chamber 63 through the compressor suction port 6 a . Then, as shown in FIGS. 10A and 11B , the compressor suction port 6 a is closed gradually after the compressor piston 62 rotates about 360°.
- the suction process is completed and the suction side space 63 a of the compressor working chamber 63 shifts to the discharge side space 63 b .
- the compressor discharge port 6 b is opened gradually, and the working fluid in the discharge side space 63 b is discharged toward the main compressor 2 through the compressor discharge port 6 b .
- Such extrusion of the working fluid by the compressor piston 62 increases the pressure of the working fluid.
- the compressor discharge port 63 b is closed gradually after the shaft 81 rotates about 300°, and is completely closed by the compressor piston 62 when the shaft 81 rotates from the point of about 85° to the point of about 90°.
- the expander suction port 4 a is closed after the compressor suction port 6 a is brought into communication with the suction side space 63 a of the compressor working chamber 63 , and the expander suction port 4 a is opened before the compressor suction port 6 a is closed.
- the flow passage of the fluid machine 8 A upstream of the expander suction port 4 a through the suction pipe 82 and the flow passage of the fluid machine 8 A upstream of the compressor suction port 6 a through the suction pipe 84 are filled with the high pressure working fluid.
- the fluid machine 8 A since the fluid machine 8 A is configured as described above, at least one of the expander suction port 4 a and the compressor suction port 6 a always is opened and the high pressure working fluid always flows into at least one of the suction side space 43 a of the expander working chamber 43 and the suction side space 63 a of the compressor working chamber 63 no matter what angular position the shaft 81 of the fluid machine 8 A takes at the start of the refrigeration cycle apparatus 1 . Therefore, no matter in what state the fluid machine 8 A is stopped, a torque for rotating the shaft 81 can be generated in one or both of the expander 4 and the compressor 6 , making it possible for the fluid machine 8 A to self-start owing to the pressure of the working fluid.
- both of the expander suction port 4 a and the compressor suction port 6 a are opened and the high pressure working fluid flows into the suction side space 43 a of the expander working chamber 43 and the suction side space 63 a of the compressor working chamber 63 .
- a torque is generated in each of the expander 4 and the compressor 6 .
- both of the expander suction port 4 a and the compressor suction port 6 a are opened and the high pressure working fluid flows into the suction side space 43 a of the expander working chamber 43 and the suction side space 63 a of the compressor working chamber 63 .
- a torque is generated in each of the expander 4 and the compressor 6 .
- the fluid machine 8 A which has no driving device, can self-start without fail at the start of the refrigeration cycle apparatus 1 owing only to the pressure of the working fluid. Therefore, the reliability of the refrigeration cycle apparatus 1 can be increased.
- the rotor plate 48 constitutes the drawing control mechanism in which the expander suction port 4 a is opened and closed as the shaft 81 rotates.
- the drawing control mechanism of the present invention is not limited to this and drawing control mechanisms with various structures can be employed.
- a drawing control mechanism with the structure disclosed in Patent Literature 1 may be employed, or a drawing control mechanism in which an arc groove is provided in an upper surface of the first eccentric portion 81 b of the shaft 81 and a communication groove that brings the arc groove into communication with the suction side space 43 a of the expander working chamber 43 is provided in the lower surface of the first closing member 49 may be employed.
- the present invention surely can realize the self-starting of the fluid machine.
- the present invention is useful particularly for refrigeration cycle apparatuses using the fluid machine as a power recovery system.
Abstract
A fluid machine (8A) includes an expander (4) having an expander suction port (4 a) and an expander discharge port (4 b), a compressor (6) having a compressor suction port (6 a) and a compressor discharge port (6 b), and a shaft (81) coupling the expander (4) to the compressor (6). The expander suction port (4 a) and the compressor suction port (4 a) are opened and closed as the shaft (81) rotates. The expander suction port (4 a) is opened during a period of time when the compressor suction port (6 a) is closed, and the compressor suction port (6 a) is opened and maintained out of communication with the compressor discharge port (6 b) during a period of time when the expander suction port (4 a) is closed.
Description
- The present invention relates to a fluid machine used for water heaters, air-conditioners, etc, and a refrigeration cycle apparatus using the fluid machine.
- Conventionally, there have been known fluid machines in which an expander and a compressor are coupled to each other by a shaft and the compressor is driven by the power recovered from a working fluid expanding in the expander. For example, Patent Literature 1 discloses a
fluid machine 100 shown inFIG. 12 . - As shown in
FIG. 12 , anexpander 110 and acompressor 120 are coupled to each other by ashaft 101 in thefluid machine 100. Both of theexpander 110 and thecompressor 120 are rotary type. Theshaft 101 has a firsteccentric portion 102 for theexpander 110 and a secondeccentric portion 103 for thecompressor 120. - As shown in
FIG. 13 , theexpander 110 has anexpander piston 112 into which the firsteccentric portion 102 of theshaft 101 is fitted, and anexpander cylinder 111 accommodating theexpander piston 112. A crescent-shapedexpander working chamber 113 is formed between an inner circumferential surface of theexpander cylinder 111 and an outer circumferential surface of theexpander piston 112. Theexpander working chamber 113 is partitioned into a suction side space and a discharge side space by anexpander partition member 114. Theexpander partition member 114 is integrated with theexpander piston 112. Acolumnar shoe 117 supporting reciprocably theexpander partition member 114 is provided rotatably to theexpander cylinder 111. That is, theexpander piston 112 swings taking the center of theshoe 117 as the pivot point while changing the distance between the supporting point and itself. - The
expander cylinder 111 is provided with asuction port 110 a through which a working fluid is introduced into theexpander working chamber 113, and adischarge port 110 b through which the working fluid is discharged from theexpander working chamber 113. Thesuction port 110 a is, at a specified timing, brought into communication with theexpander working chamber 113 through acommunication port 115 formed in theshoe 117 and acommunication groove 116 formed in theexpander partition member 113. That is, theshoe 117 and theexpander partition member 113 constitute a drawing control mechanism for opening and closing thesuction port 110 a as theshaft 101 rotates. The timing at which thesuction port 110 a is opened (in communication with the expander working chamber 113) is a period of time from when theexpander piston 112 is at a top dead center at which it retracts theexpander partition member 114 most until theexpander piston 112 rotates about 140° from the top dead center. - As shown in
FIG. 14 , thecompressor 120 has acompressor piston 122, composed of roller bearings, into which the secondeccentric portion 103 of theshaft 101 is fitted, and acompressor cylinder 121 accommodating thecompressor piston 122. A crescent-shapedcompressor working chamber 123 is formed between an inner circumferential surface of thecompressor cylinder 121 and an outer circumferential surface of thecompressor piston 122. Thecompressor working chamber 123 is partitioned into a suction side space and a discharge side space by acompressor partition member 124. Thecompressor partition member 114 is pressed against thecompressor piston 122 by a spring. - The
compressor cylinder 121 is provided with asuction port 120 a through which the working fluid is introduced into thecompressor working chamber 123. A closing member adjacent to thecompressor cylinder 121 and thecompressor piston 122 is provided with adischarge port 120 b through which the working fluid is discharged from thecompressor working chamber 113. Thesuction port 120 a opens on the inner circumferential surface of thecompressor cylinder 121. Thesuction port 120 a is closed by thecompressor piston 122 only when a sliding point of thecompressor piston 122 sliding on the inner circumferential surface of thecompressor cylinder 121 is present on thesuction port 120 a. - Patent Literature 1 also discloses a
refrigeration cycle apparatus 200 shown inFIG. 15 using thefluid machine 100. Therefrigeration cycle apparatus 200 has a configuration in which thecompressor 120 of thefluid machine 100 increases preliminarily the pressure of the working fluid to be drawn into amain compressor 210. Themain compressor 210, aradiator 220, theexpander 110, anevaporator 230, and thecompressor 120 are connected in this order by a flow passage so as to constitute a working fluid circuit. -
- PTL 1: JP 2004-324595 A
- The
fluid machine 100 includes no driving means such as a motor, and is expected to self-start owing to the pressure of the working fluid in therefrigeration cycle apparatus 200 as shown inFIG. 15 . That is, starting themain compressor 210 allows the high pressure working fluid to flow into the suction side space of theexpander working chamber 113 of theexpander 110. This causes a pressure difference between the suction side space and the discharge side space of theexpander working chamber 113, and this pressure difference applies a torque to theshaft 101 to start thefluid machine 100. - However, when the
fluid machine 100 is stopped in the state where thesuction port 110 a of theexpander 110 is closed, the high pressure working fluid cannot flow into theexpander working chamber 113 and thus no torque for rotating theshaft 101 is generated. - In contrast, the inventors of the present invention arrived at, prior to the present invention, an idea of guiding, at the time of starting, the high pressure working fluid discharged from the main compressor also to the compressor of the fluid machine to apply a torque to the shaft also in the compressor. That is, a bypass passage that links a high pressure flow passage between the main compressor and the radiator or between the radiator and the expander to a low pressure passage between the evaporator and the compressor is provided so as to allow the high pressure working fluid to flow also into the suction side space of the compressor working chamber of the compressor at the time of starting. Thereby, a pressure difference is generated also between the suction side space and the discharge side space of the compressor working chamber. As a result, a torque can be applied to the shaft also in the compressor.
- However, even when the above-mentioned technique is applied to the
fluid machine 100 disclosed in Patent Literature 1, no torque for rotating theshaft 101 is generated yet in some cases. The reason is as follows. - In the
fluid machine 100 disclosed in Patent Literature 1, the position of theexpander partition member 114 and the position of thecompressor partition member 124 coincide with each other in the axial direction of theshaft 101, and an eccentric orientation of the firsteccentric portion 102 is deviated 180° from an eccentric orientation of the secondeccentric portion 103. Moreover, in thecompressor 120, thesuction port 120 a is in communication with thedischarge port 120 b through thecompressor working chamber 123 until the sliding point of thecompressor piston 121 reaches thesuction port 120 a after passing thedischarge port 120 b. - Thus, with the rotation angle of the
shaft 101 when theexpander piston 112 is present at the top dead center being defined as 0°, the working fluid can flow into the suction side space of theexpander working chamber 113 in theexpander 110 when the rotation angle of theshaft 101 is in the range from 0° to about 140°. On the other hand, in thecompressor 120, although thesuction port 120 a of thecompressor 120 is closed by thecompressor piston 122 when the rotation angle of theshaft 101 is in the range from about 190° to about 200°, the working fluid can flow into the suction side space of thecompressor working chamber 123 when the rotation angle of theshaft 101 is out of this range. - However, when the rotation angle of the
shaft 101 is in the range from about 190° to about 200°, both of theexpander suction port 110 a and thecompressor suction port 120 a are closed, and the torque for rotating theshaft 110 is generated neither in theexpander 110 nor in thecompressor 120. Moreover, when the rotation angle of theshaft 101 is in the range from about 180°, at which the sliding point of thecompressor piston 121 passes thedischarge port 120 b, to about 190°, at which the sliding point reaches thesuction port 120 a, thesuction port 120 a is in communication with thedischarge port 120 b through thecompressor working chamber 123 as described above and the working fluid that has flowed into thecompressor working chamber 123 through thesuction port 120 a is discharged through thedischarge port 120 b. Furthermore, thesuction port 110 a of theexpander 110 is closed during that time. Therefore, when thefluid machine 100 is stopped in the state where the rotation angle of the shaft is between about 180° and about 200°, the torque for rotating theshaft 101 owing to the pressure of the working fluid cannot be generated and thefluid machine 100 cannot self-start. - In view of the foregoing, the present invention is intended to provide a fluid machine that can self-start owing to the pressure of the working fluid no matter in what state it is stopped, and a refrigeration cycle apparatus using the fluid machine.
- In order to solve the above-mentioned problems, the present invention provides a fluid machine including: an expander that expands a working fluid drawn through an expander suction port and discharges the working fluid through an expander discharge port so as to recover power from the working fluid; a compressor that increases a pressure of the working fluid drawn through a compressor suction port and discharges the working fluid through a compressor discharge port; and a shaft that couples the expander to the compressor so that the compressor is driven by the power recovered by the expander. The expander suction port and the compressor suction port are opened and closed as the shaft rotates. The expander suction port is opened during a period of time when the compressor suction port is closed, and the compressor suction port is opened and maintained out of communication with the compressor discharge port during a period of time when the expander suction port is closed.
- The present invention also provides a refrigeration cycle apparatus using the fluid machine, including: a working fluid circuit through which a working fluid circulates, the working fluid circuit including a main compressor for compressing the working fluid, a radiator for radiating heat from the compressed working fluid, the expander for expanding the working fluid that has flowed out of the radiator, an evaporator for evaporating the expanded working fluid, and the compressor for increasing a pressure of the working fluid that has flowed out of the evaporator and supplying the working fluid to the main compressor; and a bypass passage linking a portion between the main compressor and the radiator or a portion between the radiator and the expander to a portion between the evaporator and the compressor in the working fluid circuit.
- According to the above-mentioned configuration, the working fluid can always flow into one or both of the suction side space of the expander working chamber and the suction side space of the compressor working chamber. In the compressor working chamber, the working fluid that has flowed therein is prevented from being discharged through the compressor discharge port. Therefore, the fluid machine can self-start owing to the pressure of the working fluid no matter in what state it is stopped.
-
FIG. 1 is a configuration diagram of a refrigeration cycle apparatus using a fluid machine according to Embodiment 1 of the present invention. -
FIG. 2 is a vertical cross-sectional view of the fluid machine according to Embodiment 1 of the present invention. -
FIG. 3 is a cross-sectional view taken along the line III-III inFIG. 2 . -
FIG. 4 is a cross-sectional view taken along the line IV-IV inFIG. 2 . -
FIG. 5 is a cross-sectional view taken along the line V-V inFIG. 2 . -
FIGS. 6A to 6C each are a diagram illustrating the operating principle of the fluid machine according to Embodiment 1 of the present invention. -
FIGS. 7A to 7C each are a diagram illustrating the operating principle of the fluid machine according to Embodiment 1 of the present invention. -
FIG. 8 is a vertical cross-sectional view of a fluid machine according toEmbodiment 2 of the present invention. -
FIG. 9 is a cross-sectional view taken along the line IX-IX inFIG. 8 . -
FIGS. 10A to 10C each are a diagram illustrating the operating principle of the fluid machine according toEmbodiment 2 of the present invention. -
FIGS. 11A to 11C each are a diagram illustrating the operating principle of the fluid machine according toEmbodiment 2 of the present invention. -
FIG. 12 is a vertical cross-sectional view of a conventional fluid machine. -
FIG. 13 is a cross-sectional view taken along the line A-A inFIG. 12 . -
FIG. 14 is a cross-sectional view taken along the line B-B inFIG. 12 . -
FIG. 15 is a configuration diagram of a refrigeration cycle using the fluid machine shown inFIG. 12 . - Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention, however, is not limited to the following embodiments.
-
FIG. 1 is a configuration diagram of a refrigeration cycle apparatus 1 using afluid machine 8A according to Embodiment 1 of the present invention. The refrigeration cycle apparatus 1 is provided with a workingfluid circuit 7 through which a working fluid (refrigerant) circulates. The workingfluid circuit 7 includes amain compressor 2, aradiator 3, anexpander 4, anevaporator 5, and acompressor 6 as a sub compressor. Thesecomponents 2 to 6 are connected in this order by a first to fifth flow passages (pipes) 7 a to 7 e. As the working fluid, carbon dioxide and chlorofluorocarbon alternative can be used, for example. - The
main compressor 2 has, in a singleclosed casing 2 c holding a lubricating oil, acompression mechanism 2 a and amotor 2 b for driving thecompression mechanism 2 a. Themain compressor 2 compresses the working fluid at high temperature and high pressure. As themain compressor 2, a scroll type compressor and a rotary type compressor can be used, for example. A discharge mouth of themain compressor 2 is connected to an inlet of theradiator 3 through thefirst flow passage 7 a. - The
radiator 3 radiates heat from the high temperature, high pressure working fluid compressed in themain compressor 2 to cool the working fluid. An outlet of theradiator 3 is connected to a suction mouth of theexpander 4 through thesecond flow passage 7 b. - The
expander 4 expands the middle temperature, high pressure working fluid that has flowed out of theradiator 3 and converts the expansion energy of the working fluid into mechanical energy, thereby recovering power from the working fluid. In the present embodiment, theexpander 4 is a rotary type expander (details will be described later). A discharge mouth of theexpander 4 is connected to an inlet of theevaporator 5 through thethird flow passage 7 c. - The
evaporator 5 heats the low temperature, low pressure working fluid that has been expanded in theexpander 4 to evaporate the working fluid. An outlet of theevaporator 5 is connected to a suction mouth of thecompressor 6 through thefourth flow passage 7 d. - The
compressor 6 increases preliminary the pressure of the middle temperature, low pressure working fluid that has flowed out of theevaporator 5 and supplies the working fluid to themain compressor 2. In the present embodiment, thecompressor 6 is a rotary type compressor (details will be described later). A discharge mouth of thecompressor 6 is connected to a suction mouth of themain compressor 2 through thefifth flow passage 7 e. - The
expander 4 and thecompressor 6 are disposed in a singleclosed casing 80 holding a lubricating oil, while being coupled to each other by ashaft 81, to constitute thefluid machine 8A. That is, the power recovered by theexpander 4 is transferred to thecompressor 6 via theshaft 81, thereby driving thecompressor 6. - The refrigeration cycle apparatus 1 shown in
FIG. 1 further is provided with afirst bypass passage 91 with its both ends being connected to the workingfluid circuit 7 so as to bypass theevaporator 5 and thecompressor 6, and a second bypass passage (corresponding to a bypass passage of the present invention) 93 with its both ends being connected to the workingfluid circuit 7 so as to bypass theexpander 4 and theevaporator 5. Thefirst bypass passage 91 has afirst bypass valve 92 for controlling the flow of the working fluid in thefirst bypass passage 91. Thesecond bypass passage 93 has asecond bypass valve 94 for controlling the flow of the working fluid in thesecond bypass passage 93. - The
first bypass passage 91 links thethird flow passage 7 c for guiding the working fluid from the discharge mouth of theexpander 4 to the inlet of theevaporator 5 to thefifth flow passage 7 e for guiding the working fluid from the discharge mouth of thecompressor 6 to the suction mouth of themain compressor 2. That is, thefirst bypass passage 91 is a flow passage that allows the working fluid discharged from theexpander 4 to bypass theevaporator 5 and thecompressor 6 so as to be drawn directly into themain compressor 2. In the present embodiment, a check valve is used as thefirst bypass valve 92. However, thefirst bypass valve 92 is not limited to this, and an opening and closing valve or a three-way valve may be used. - The
first bypass valve 92 allows the working fluid to flow through thefirst bypass passage 91 when the working fluid in thefirst bypass passage 91 downstream (outlet side) of thefirst bypass valve 92 has a lower pressure than that of the working fluid in thefirst bypass passage 91 upstream (inlet side) of thefirst bypass valve 92. In the opposite case, thefirst bypass valve 92 prohibits the working fluid from flowing through thefirst bypass passage 91. That is, the working fluid flows from thethird flow passage 7 c into thefifth flow passage 7 e through thefirst bypass passage 91 when the working fluid in thefifth flow passage 7 e between the discharge mouth of thecompressor 6 and the suction mouth of themain compressor 2 has a lower pressure than that of the working fluid in the flow passage (thethird flow passage 7 c, theevaporator 5, and thefourth flow passage 7 d) between the discharge mouth of theexpander 4 and the suction mouth of thecompressor 6. - The
second bypass passage 93 links thesecond flow passage 7 b for guiding the working fluid from the outlet of theradiator 3 to the suction mouth of theexpander 4 to thefourth flow passage 7 d for guiding the working fluid from the outlet of theevaporator 5 to the suction mouth of thecompressor 6. That is, thesecond bypass passage 93 is a flow passage that allows the high pressure working fluid that has flowed out of theradiator 3 to bypass theexpander 4 and theevaporator 5 so as to be drawn directly into thecompressor 6. In the present embodiment, an opening and closing valve is used as thesecond bypass valve 94. However, thesecond bypass valve 94 is not limited to this, and a three-way valve may be used. Moreover, thesecond bypass passage 92 has only to be a flow passage that allows the high pressure working fluid to be drawn directly into thecompressor 6. Thesecond bypass passage 92 may link thefirst flow passage 7 a for guiding the working fluid from the discharge mouth of themain compressor 2 to the inlet of theradiator 3 to thefourth flow passage 7 d. - The
second bypass valve 94 is opened in the start control, and thereby the high pressure working fluid that has flowed out of theradiator 3 flows from thesecond flow passage 7 b into thefourth flow passage 7 d through thesecond bypass passage 93. - In the refrigeration cycle apparatus 1 shown in
FIG. 1 , a compressorupstream valve 71 for controlling the flow of the working fluid in thefourth flow passage 7 d is provided to thefourth flow passage 7 d between the outlet of theevaporator 5 and the position at which a downstream end of thesecond bypass passage 93 is connected to thefourth flow passage 7 d. In the present embodiment, an opening and closing valve is used as the compressorupstream valve 71. The compressorupstream valve 71 is closed in the start control so as to prevent the working fluid from flowing from theevaporator 5 into thecompressor 6 and prevent the working fluid that has flowed into thefourth flow passage 7 d through thesecond bypass passage 93 from flowing into theevaporator 5. - The
second bypass valve 94 and the compressorupstream valve 71 are controlled by a controller that is not shown. Moreover, the refrigeration cycle apparatus 1 is provided, although not shown, with a start detection means for detecting that thecompressor 6 is started. When thecompressor 6 is started, a detection signal is transmitted from the start detection means to the controller. As the start detection means, it is possible to use a method, with a thermocouple provided to thethird flow passage 7 c on a discharge side of theexpander 4, to measure the temperature of the working fluid in thethird flow passage 7 c, for example. - <Operation of Refrigeration Cycle Apparatus>
- The refrigeration cycle apparatus 1 performs the start control first, and then initiates steady operation. In the refrigeration cycle apparatus 1, the pressure of the working fluid in the working
fluid circuit 7 is approximately uniform when the refrigeration cycle apparatus 1 is in standby state (stopped state) for operation. - In the start control, the
second bypass valve 94 is opened and the compressorupstream valve 71 is closed first. Thereby, thesecond bypass passage 93 is opened through and thefourth flow passage 7 d is blocked between the outlet of theevaporator 5 and the downstream end of thesecond bypass passage 93. Subsequently, themain compressor 2 is started and the working fluid in thefifth flow passage 7 e and the working fluid in thefirst bypass passage 91 downstream of thefirst bypass valve 92 are drawn into themain compressor 2. - When the drawing of the working fluid into the
main compressor 2 begins, the pressures of the working fluid in thefifth flow passage 7 e and the working fluid in thefirst bypass passage 91 downstream of thefirst bypass valve 92 are lowered. Thereby, thefirst bypass valve 92, which is a check valve, is opened, and the working fluid in the flow passage (thethird flow passage 7 c, theevaporator 5, and a part of thefourth flow passage 7 d) from the discharge mouth of theexpander 4 to the compressorupstream valve 71 flows into thefirst bypass passage 91. That is, the working fluid in the flow passage from the discharge mouth of theexpander 4 to the compressorupstream valve 71 is drawn into themain compressor 2 together with the working fluid in the first bypass passage 9 and the working fluid in thefifth flow passage 7 e so as to be compressed and discharged into thefirst flow passage 7 a. As a result, the pressure of the working fluid in thefirst bypass passage 91 upstream of thefirst bypass valve 92 and the working fluid in the flow passage from the discharge mouth of theexpander 4 to the compressorupstream valve 71 are lowered. - In contrast, the pressure of the working fluid in the flow passage (the
first flow passage 7 a, theradiator 3, and thesecond flow passage 7 b) from the discharge mouth of themain compressor 2 to the suction mouth of theexpander 4 is increased because the working fluid drawn into themain compressor 2 is compressed and discharged. Moreover, since thesecond bypass valve 94 is opened and the compressorupstream valve 71 is closed in the start control, the working fluid in the flow passage from the discharge mouth of themain compressor 2 to the suction mouth of theexpander 4 flows, through thesecond bypass passage 93, also into a portion of thefourth flow passage 7 d between the compressorupstream valve 71 and the suction mouth of thecompressor 6. This increases the pressure of the working fluid in the flow passage (a part of thefourth flow passage 7 d) from the compressorupstream valve 71 to the suction mouth of thecompressor 6. - Therefore, high pressure-low pressure differences occur between the working fluid (high pressure) in the flow passage (the
second flow passage 7 b) on a side of the suction mouth of theexpander 4 and the working fluid (low pressure) in the flow passage (thethird flow passage 7 c) on a side of the discharge mouth of theexpander 4, and between the working fluid (high pressure) in the flow passage (a part of thefourth flow passage 7 d) on a side of the suction mouth of thecompressor 6 and the working fluid (low pressure) in the flow passage (thefifth flow passage 7 e) on a side of the discharge mouth of thecompressor 6, respectively. These high pressure-low pressure differences between the working fluids act on theexpander 4 and thecompressor 6, respectively, making it possible for thefluid machine 8A to self-start easily. - When the above-mentioned start detection means detects that the
compressor 6 is started, thesecond bypass valve 94 is closed and the compressorupstream valve 71 is opened. Thereby, thesecond bypass passage 93 is blocked and thefourth flow passage 7 d is opened through. Then the refrigeration cycle apparatus 1 ends the start control and shifts to the steady operation in which the working fluid circulates through the workingfluid circuit 7. - During the steady operation, the working fluid in the
fourth flow passage 7 d and the working fluid in thesecond bypass passage 93 downstream of thesecond bypass valve 94 are drawn into thecompressor 6 and its pressure is increased, and the working fluid is discharged into thefifth flow passage 7 e. Thereby, the working fluid in thefifth flow passage 7 e and the working fluid in thefirst bypass passage 91 downstream of thefirst bypass valve 92 have a higher pressure than the pressure of the working fluid in the flow passage (thethird flow passage 7 c, theevaporator 5, and thefourth flow passage 7 d) from the discharge mouth of theexpander 4 to the suction mouth of thecompressor 6 and the pressure of the working fluid in thefirst bypass passage 91 upstream of thefirst bypass valve 92. Thus, thefirst bypass valve 92, which is a check valve, is closed. During the steady operation, the working fluid in thefifth flow passage 7 e and the working fluid in thefirst bypass passage 91 downstream of thefirst bypass valve 92 have a high pressure as in the case above, and thus thefirst bypass valve 92 remains closed. Thereby, the working fluid during the steady operation circulates through the workingfluid circuit 7. - <Configuration of Fluid Machine>
- Next, the configuration of the
fluid machine 8A will be described in detail.FIG. 2 is a vertical cross-sectional view of thefluid machine 8A.FIGS. 3 to 5 are transverse cross-sectional views of thefluid machine 8A taken along the lines III-III to V-V inFIG. 2 , respectively. InFIGS. 3 to 5 , theclosed casing 80 is omitted. - As described above, the
fluid machine 8A is a power recovering system in which theexpander 4 and thecompressor 6 are coupled to each other by theshaft 81 so that the power recovered by theexpander 4 drives thecompressor 6. In the present embodiment, theshaft 81 extends in a vertical direction, theexpander 4 is disposed at a lower part in theclosed casing 80, and thecompressor 6 is disposed at an upper part in theclosed casing 80. However, the positional relationship between theexpander 4 and thecompressor 6 may be vertically opposite. Theshaft 81 may extend in a lateral direction so that theexpander 4 and thecompressor 6 are aligned in the lateral direction. Theclosed casing 80 is filled with the lubricating oil to an extent that the oil level is present above thecompressor 6. - 1) Shaft
- The
shaft 81 has a firsteccentric portion 81 b for theexpander 4 and a secondeccentric portion 81 c for thecompressor 6 as eccentric portions, each having a central axis at a location away from the axial center of theshaft 81. Anoil supply passage 81 a that penetrates through theshaft 81 in the axial direction and that opens on an outer circumferential surface of the firsteccentric portion 81 b, an outer circumferential surface of the secondeccentric portion 81 c, etc. is formed in theshaft 81. Through theoil supply passage 81 a, the lubricating oil in theclosed casing 80 is supplied to the sliding parts, etc. of theexpander 4 and thecompressor 6. - 2) Expander
- As described above, the
expander 4 is a rotary type expander in the present embodiment. However, theexpander 4 is not limited to the rotary type expander and may be a scroll type expander or another type of expander. Theexpander 4 expands the working fluid drawn through theexpander suction port 4 a and discharges the working fluid through theexpander discharge port 4 b so as to recover power from the working fluid. - Specifically, as shown in
FIG. 4 , theexpander 4 has anexpander piston 42 into which the firsteccentric portion 81 b of theshaft 81 is fitted, and anexpander cylinder 41 accommodating theexpander piston 42. Theexpander cylinder 41 has an inner circumferential surface forming a cylindrical surface whose central axis coincides with the axial center of theshaft 81. Theexpander piston 42 performs an eccentric rotational motion along the inner circumferential surface of theexpander cylinder 41 as theshaft 81 rotates. That is, a crescent-shapedexpander working chamber 43 is formed between the inner circumferential surface of theexpander cylinder 41 and an outer circumferential surface of theexpander piston 42. - The
expander working chamber 43 is partitioned into asuction side space 43 a and adischarge side space 43 b by anexpander partition member 44. Theexpander suction port 4 a opens to a portion of thesuction side space 43 a adjacent to theexpander partition member 44. Theexpander discharge port 4 b opens to a portion of thedischarge side space 43 b adjacent to theexpander partition member 44. - The
expander partition member 44 has a plate-like shape and is inserted reciprocably in agroove 41 a formed in theexpander cylinder 41. Thegroove 41 a opens to theexpander working chamber 43, on a straight line passing the axial center of theshaft 81. A biasing means 45 for pressing theexpander partition member 44 against the outer circumferential surface of theexpander piston 42 is disposed between a bottom of thegroove 41 a and theexpander partition member 44. - The biasing means 45 can be composed of a compression coil spring, for example. The biasing means 45 may be a so-called gas spring configured by making a back space between a rear edge of the
expander partition member 44 and the bottom of thegroove 41 a a closed space. The biasing means 45 may be composed of two or more types of springs, such as the compression coil spring and the gas spring, of course. Theexpander piston 42 and theexpander partition member 44 may be integrated with each other, without the biasing means 45 being provided. - As shown in
FIG. 2 , theexpander 4 has a first closing member (inner closing member) 49 for closing theexpander working chamber 43 from a side of thecompressor 6, a second closing member (outer closing member) 46 for closing theexpander working chamber 43 from a side opposite to thecompressor 6, and a bearingmember 47 disposed below thesecond closing member 46. - The bearing
member 47 is fixed to an inner circumferential surface of theclosed casing 80 and supports rotatably a lower part of theshaft 81. Thesecond closing member 46, theexpander cylinder 41, and thefirst closing member 49 are stacked in this order on the bearingmember 47. Asuction pipe 82 and adischarge pipe 83 penetrating through theclosed casing 80 are connected to the bearingmember 47. - The
first closing member 49 and thesecond closing member 46 each have a disc shape that is flattened in the axial direction of theshaft 81. Theshaft 81 penetrates through the centers of thefirst closing member 49 and thesecond closing member 46. In the present embodiment, theexpander suction port 4 a is provided in thesecond closing member 46 and theexpander discharge port 4 b is provided in thefirst closing member 49 and theexpander cylinder 41. - A circular recessed
portion 46 a whose center coincides with the axial center of theshaft 81 is provided on a lower surface of thesecond closing member 46. Theexpander suction port 4 a penetrates through thesecond closing member 46 in the axial direction of theshaft 81 so as to extend straightly from an upper surface of thesecond closing member 46 to a bottom surface of the recessedportion 46 a. Theexpander suction port 4 a is in communication with thesuction pipe 82 through a suction space inside the recessedportion 46 a and asuction passage 47 a formed in the bearingmember 47. That is, the high pressure working fluid from thesecond flow passage 7 b shown inFIG. 1 is guided from theexpander suction port 4 a to thesuction side space 43 a of theexpander working chamber 43 through thesuction pipe 82, thesuction passage 47 a, and the suction space inside the recessedportion 46 a. - On the other hand, as shown in
FIG. 4 , theexpander discharge port 4 b is constructed of avertical groove 41 b recessed radially outward and formed in the inner circumferential surface of theexpander cylinder 41, and alateral groove 49 a formed in a lower surface of thefirst closing member 49 so as to extend radially outward from a position corresponding to thevertical groove 41 b. An outer end of theexpander discharge port 4 b is in communication with thedischarge pipe 83 through adischarge passage 4 c formed so as to extend across theexpander cylinder 41, thesecond closing member 46, and the bearingmember 47. That is, the working fluid in thedischarge side space 43 b of theexpander working chamber 43 is discharged into thethird flow passage 7 c shown inFIG. 1 through theexpander discharge port 4 b, thedischarge passage 4 c, and thedischarge pipe 83. - Further, inside the recessed
portion 46 a, arotor plate 48 is disposed as a drawing control mechanism for opening and closing theexpander suction port 4 a as theshaft 81 rotates. Therotor plate 48 is attached to theshaft 81 so as to rotate while being in contact with the bottom surface of the recessedportion 46 a. - As shown in
FIG. 4 , theexpander suction port 4 a extends in an arc shape from a vicinity of theexpander partition member 44 along the inner circumferential surface of theexpander cylinder 41. As shown inFIG. 3 , therotor plate 48 has alarge diameter portion 48 a for blocking theexpander suction port 4 a and asmall diameter portion 48 b for exposing theexpander suction port 4 a. - In the present embodiment, the
expander suction port 4 a is exposed partly or completely when theexpander piston 41 rotates 140° from a top dead center, and theexpander suction port 4 a is completely blocked by thelarge diameter portion 48 a anytime other than this period, according to the angle ranges and positions of thelarge diameter portion 48 a and thesmall diameter portion 48 b. Here, the top dead center refers to a location at which a sliding point of theexpander piston 42 sliding on the inner circumferential surface of theexpander cylinder 41 coincides with theexpander partition member 44. - The configuration of the
expander 4 can be inverted vertically. That is, thefirst closing member 49, theexpander cylinder 41, thesecond closing member 46, therotor plate 48, and the bearingmember 47 may be disposed in this order from bottom to top so that thefirst closing member 49 serves as the outer closing member and thesecond closing member 46 serves as the inner closing member. In this case, the bearingmember 47 may fit loosely around theshaft 81, and thefirst closing member 49 may have a function of supporting rotatably the lower part of theshaft 81. - 3) Compressor
- As described above, the
compressor 6 is a rotary type compressor in the present embodiment. Thecompressor 6 increases the pressure of the working fluid drawn through thecompressor suction port 6 a and discharges the working fluid through thecompressor discharge port 6 b. - Specifically, as shown in
FIG. 5 , thecompressor 6 has acompressor piston 62 into which the secondeccentric portion 81 c of theshaft 81 is fitted, and acompressor cylinder 61 accommodating thecompressor piston 62. Thecompressor cylinder 61 has an inner circumferential surface forming a cylindrical surface whose central axis coincides with the axial center of theshaft 81. Thecompressor piston 62 performs an eccentric rotational motion along the inner circumferential surface of thecompressor cylinder 61 as theshaft 81 rotates. That is, a crescent-shapedcompressor working chamber 63 is formed between the inner circumferential surface of thecompressor cylinder 61 and an outer circumferential surfaces of thecompressor piston 62. - The
compressor working chamber 63 is partitioned into asuction side space 63 a and adischarge side space 63 b by ancompressor partition member 64. Thecompressor suction port 6 a opens to a portion of thesuction side space 63 a adjacent to thecompressor partition member 64. Thecompressor discharge port 6 b opens to a portion of thedischarge side space 63 b adjacent to thecompressor partition member 64. - The
compressor partition member 64 has a plate-like shape and is inserted reciprocably in agroove 61 a formed in thecompressor cylinder 61. Thegroove 61 a opens to thecompressor working chamber 63, on a straight line passing the axial center of theshaft 81. A biasing means 65 for pressing thecompressor partition member 64 against the outer circumferential surface of thecompressor piston 62 is disposed between a bottom of thegroove 61 a and thecompressor partition member 64. - The biasing means 65 can be composed of a compression coil spring, for example. The biasing means 65 may be a so-called gas spring configured by making a back space between a rear edge of the
compressor partition member 64 and the bottom of thegroove 61 a a closed space. The biasing means 65 may be composed of two or more types of springs, such as the compression coil spring and the gas spring, of course. Thecompressor piston 62 and thecompressor partition member 64 may be integrated with each other, without the biasing means 65 being provided. - Moreover, as shown in
FIG. 2 , thecompressor 6 has the first closing member (inner closing member) 49 for closing thecompressor working chamber 63 from a side of theexpander 4, a second closing member (outer closing member) 66 for closing thecompressor working chamber 63 from a side opposite to theexpander 4, and a cover member 67 disposed above thesecond closing member 46. That is, theexpander 4 and thecompressor 6 share thefirst closing member 49 in the present embodiment. However, theexpander 4 and thecompressor 6 may have the first closing members, respectively. - The
second closing member 66 has a function as a bearing member for supporting rotatably an upper part of theshaft 81. Thecompressor cylinder 61, thesecond closing member 66, and the cover member 67 are stacked in this order on thefirst closing member 49. Asuction pipe 84 penetrating through theclosed casing 80 is connected to thecompressor cylinder 61. Adischarge pipe 85 penetrating through theclosed casing 80 is connected to thesecond closing member 66. - The
second closing member 66 has a disc shape that is flattened in the axial direction of theshaft 81. Theshaft 81 penetrates through the center of thesecond closing member 66. The cover member 67 also has a disc shape that is flattened in the axial direction of theshaft 81. At the center of the cover member 67, an opening through which an upper end portion of theshaft 81 is exposed is provided. In the present embodiment, thecompressor suction port 6 a is provided in thecompressor cylinder 61 and thecompressor discharge port 6 b is provided in thesecond closing member 66. - The
compressor suction port 6 a penetrates laterally through thecompressor cylinder 61. Thecompressor suction port 6 a opens approximately circularly on the inner circumferential surface of thecompressor cylinder 61, and is in communication with thesuction pipe 84. That is, the low pressure (high pressure during the start control) working fluid from thefourth flow passage 7 d shown inFIG. 1 is guided from thecompressor suction port 6 a to thesuction side space 63 a of thecompressor working chamber 63 through thesuction pipe 84. - Since the
compressor suction port 6 a opens on the inner circumferential surface of thecompressor cylinder 61, it is opened and closed by thecompressor piston 62 as the shaft rotates. More specifically, thecompressor suction port 6 a is closed by thecompressor piston 62 only when the sliding point of thecompressor piston 62 sliding on the inner circumferential surface of thecompressor cylinder 61 is present on thecompressor suction port 6 a, in other words, only when thecompressor piston 62 rotates from the point of about 5° to the point of about 15°, with a top dead center (a location at which the sliding point of thecompressor piston 62 coincides with the compressor partition member 64) being defined as 0°. In a strict sense, thecompressor suction port 6 a is not completely closed by thecompressor piston 62 because the inner circumferential surface of thecompressor cylinder 61 and the outer circumferential surface of thecompressor piston 62 have different diameters from each other. However, in this description, it is defined, as described above, that thecompressor suction port 6 a is closed when the sliding point of thecompressor piston 62 is present on thecompressor suction port 6 a. - In contrast, a discharge chamber 66 a opening upward and closed by the cover member 67, and a discharge passage 66 b extending from the discharge chamber 66 a to the
discharge pipe 85 are formed in thesecond closing member 66. Thecompressor discharge port 6 b has a circular section and penetrates through thesecond closing member 66 in the axial direction of theshaft 81 so as to extend straightly from a lower surface of thesecond closing member 66 to the discharge chamber 66 a. Thecompressor discharge port 6 b is in communication with thedischarge pipe 85 through the discharge chamber 66 a and the discharge passage 66 b. That is, the working fluid in thedischarge side space 63 b of thecompressor working chamber 63 is discharged into thefifth flow passage 7 e shown inFIG. 1 through thecompressor discharge port 6 b, the discharge chamber 66 a, the discharge passage 66 b, and thedischarge pipe 85. - In the present embodiment, since the
compressor discharge port 6 b is disposed at a location that allows it to be crossed by the inner circumferential surface of thecompressor cylinder 61, thecompressor discharge port 6 b is closed by thecompressor piston 62 only when the sliding point of thecompressor piston 62 is present on thecompressor discharge port 6 b, in other words, only when thecompressor piston 62 rotates from the point of about 345° to the point of about 355°, with the top dead center being defined as 0°. As in the case of thecompressor suction port 6 a, thecompressor discharge port 6 b is not completely closed by thecompressor piston 62 in a strict sense. However, in this description, it is defined, as described above, that thecompressor discharge port 6 b is closed when the sliding point of thecompressor piston 62 is present on thecompressor discharge port 6 b. - A discharge valve 68 that, by being deformed elastically, opens and closes automatically the
compressor discharge port 6 b owing to the pressure of thedischarge side space 63 b of thecompressor working chamber 63 is disposed in the discharge chamber 66 a. - Forming the
compressor suction port 6 a as described above makes it possible to reduce the passage resistance of the working fluid flowing into thecompressor working chamber 63 and suppress the decrease in the pressure of the working fluid to be drawn into thecompressor 6. Moreover, forming thecompressor discharge port 6 b as described above makes it possible to simplify the structure of thecompressor 6, reduce the passage resistance of the working fluid flowing out of thecompressor working chamber 63, and suppress the decrease in the pressure of the working fluid to be discharged from thecompressor 6. - The configuration of the
compressor 6 can be inverted vertically. That is, the cover member 67, thesecond closing member 66, thecompressor cylinder 61, and thefirst closing member 49 may be disposed in this order from bottom to top so that thefirst closing member 49 serves as the outer closing member and thesecond closing member 66 serves as the inner closing member. In this case, thesecond closing member 66 may fit loosely around theshaft 81, and thefirst closing member 49 may have a function of supporting rotatably the upper part of theshaft 81. - 4) Correlation
- The
fluid machine 8A is configured so that theexpander suction port 6 a is opened during a period of time when thecompressor suction port 6 a is closed, and thecompressor suction port 6 a is opened and maintained out of communication with thecompressor discharge port 6 b during a period of time when theexpander suction port 6 a is closed. Specifically, theshaft 81, theexpander 4, and thecompressor 6 are configured so that thecompressor piston 62 passes the top dead center within a period of time when theexpander suction port 6 a is opened. - In order to achieve this configuration, Formula 1 below preferably is satisfied where, when a rotation direction of the
shaft 81 is defined as positive, βc (−180°<βc≦180°) indicates a phase difference of an eccentric orientation of the secondeccentric portion 81 c with respect to an eccentric orientation of the firsteccentric portion 81 b, βv (−180°<βc≦180°) indicates a phase difference of a position of thecompressor partition member 64 with respect to a position of theexpander partition member 44, and further θo indicates a rotation angle of the shaft during the period of time when theexpander suction port 6 a is opened. -
0.25θo≦βv−βc≦0.75θo (Formula 1) - In the present embodiment, as shown in
FIG. 4 andFIG. 5 , the position of theexpander partition member 44 and the position of thecompressor partition member 64 coincide with each other in the axial direction of theshaft 81, and the eccentric orientation of the secondeccentric portion 81 c is deviated −90° from the eccentric orientation of the firsteccentric portion 81 b. That is, βc=−90°, βv=0°, and βv−βc=90°. Moreover, due to the shape of therotor plate 48 as described above, θo=about 140°, leading to 0.25θo≈35° and 0.75θo105°, which satisfies Formula 1. - The present invention is not limited to this. For example, it may be configured so that the first
eccentric portion 81 b and the secondeccentric portion 81 c are eccentric in the same direction and the position of theexpander partition member 44 and the position of thecompressor partition member 64 are deviated from each other within a range that satisfies Formula 1, or so that deviations occur in terms both of the eccentric orientation and the position of the partition members within ranges that satisfy Formula 1. - <Operation of Fluid Machine>
- Next, the operation of the
fluid machine 8A during the steady operation will be described with reference toFIGS. 6A to 6C andFIGS. 7A to 7C . In these figures, the rotation angle θ of theshaft 81 when theexpander piston 42 is present at the top dead center is defined as 0°. - First, the operation of the
expander 4 will be explained. As shown inFIGS. 6A to 6C , theshaft 81 rotates from θ=0° and therotor plate 48 rotates synchronously with it, so that theexpander suction port 4 a starts being exposed out of therotor plate 48 and theexpander suction port 4 a is opened. Accordingly, the high pressure working fluid from theradiator 3 is drawn into thesuction side space 43 a of theexpander working chamber 43 through theexpander suction port 4 a. Thereafter, theexpander suction port 4 a is exposed completely when theshaft 81 rotates about 30°. On the other hand, as shown inFIGS. 7A and 7B , theexpander suction port 4 a starts being blocked by therotor plate 48 when theshaft 81 rotates about 125°, and theexpander suction port 4 a is blocked completely when theshaft 81 rotates about 140°. Thereby, the suction process is completed. - Thereafter, as shown in
FIG. 7C , the volumetric capacity of thesuction side space 63 a of theexpander working chamber 63 increases gradually as theshaft 81 rotates, and thereby the working fluid is expanded and a torque is applied to theshaft 81. The torque applied to theshaft 81 is used as the power for thecompressor 6. Theshaft 81 rotates 360° and theexpander piston 42 passes the top dead center, so that thesuction side space 43 a of theexpander working chamber 43 shifts to thedischarge side space 43 b. Then, theshaft 81 makes one rotation, so that the expanded working fluid is discharged from thedischarge side space 63 b toward theevaporator 5 through theexpander discharge port 4 b. - Next, the operation of the
compressor 6 will be described. Theshaft 81 is rotated by the power recovered by theexpander 4. With the rotation of theshaft 81, thecompressor piston 62 also rotates, and thereby thecompressor 6 is driven. - As shown in
FIG. 6C andFIG. 7A , thecompressor suction port 6 a is opened when theshaft 81 rotates about 105°, and the low pressure working fluid from theevaporator 5 is drawn into thesuction side space 63 a of thecompressor working chamber 63 through thecompressor suction port 6 a. Then, thecompressor piston 62 rotates further and thesuction side space 63 a of thecompressor working chamber 63 is brought into communication with thecompressor discharge port 6 b, and thereafter thecompressor piston 62 passes the top dead center. Thereby, thesuction side space 63 a of thecompressor working chamber 63 shifts to thedischarge side space 63 b, so that the volumetric capacity of thedischarge side space 63 b of thecompressor working chamber 63 decreases gradually as theshaft 81 rotates. This compresses the working fluid in thedischarge side space 63 b of thecompressor working chamber 63, increasing the pressure of the working fluid. When the pressure of the working fluid in thedischarge side space 63 b of thecompressor working chamber 63 becomes higher than the pressure of the working fluid in the discharge chamber 66 a, the working fluid in thedischarge side space 63 b presses and opens the discharge valve 68 and is discharged toward themain compressor 2 through thecompressor discharge port 6 b. - <Actions and Effects of the Present Embodiment>
- As described above, in the present embodiment, the
expander suction port 4 a is opened during the period of time when θ=0° to about 140°, and theexpander suction port 4 a is closed during the period of time when θ=about 140° to 360°. On the other hand, thecompressor suction port 6 a is closed during the period of time when θ=about 95° to about 105°, and thecompressor suction port 6 a is opened during the periods of time when θ=0° to about 95° and θ=about 105° to 360°. Moreover, thecompressor discharge port 6 b is in communication with thecompressor discharge port 6 b through thecompressor working chamber 63 during the period of time when θ=about 85° to about 95°. That is, theexpander suction port 4 a is closed after thecompressor suction port 6 a is brought into communication with thesuction side space 63 a of thecompressor working chamber 63, and theexpander suction port 4 a is opened before thesuction side space 63 a of thecompressor working chamber 63 is brought into communication with thecompressor discharge port 6 b. - As described in the section <Operation of refrigeration cycle apparatus>, since, at the start of the refrigeration cycle apparatus 1, the
main compressor 2 is started in the state in which thesecond bypass valve 94 is opened and the compressorupstream valve 71 is closed, high pressure-low pressure differences occur between the working fluid in the flow passage on the side of the suction mouth of theexpander 4 and the working fluid in the flow passage on the side of the discharge mouth of theexpander 4, and between the working fluid in the flow passage on the side of the suction mouth of thecompressor 6 and the working fluid in the flow passage on the side of the discharge mouth of thecompressor 6, respectively. In other words, the flow passage of thefluid machine 8A upstream of theexpander suction port 4 a through thesuction pipe 82 and the flow passage of thefluid machine 8A upstream of thecompressor suction port 6 a through thesuction pipe 84 are filled with the high pressure working fluid. - In the present embodiment, since the
fluid machine 8A is configured as described above, at least one of theexpander suction port 4 a and thecompressor suction port 6 a always is opened and the high pressure working fluid always flows into at least one of thesuction side space 43 a of theexpander working chamber 43 and thesuction side space 63 a of thecompressor working chamber 63 no matter what angular position theshaft 81 of thefluid machine 8A takes at the start of the refrigeration cycle apparatus. Moreover, it is after theexpander suction port 4 a is opened that thecompressor suction port 6 a is brought into communication with thecompressor discharge port 63 b through thecompressor working chamber 63. Therefore, no matter in what state thefluid machine 8A is stopped, a torque for rotating theshaft 81 can be generated in one or both of theexpander 4 and thecompressor 6, making it possible for thefluid machine 8A to self-start owing to the pressure of the working fluid. - Specifically, when the
shaft 81 is in the range of θ=0° to about 85°, both of theexpander suction port 4 a and thecompressor suction port 6 a are opened and the high pressure working fluid flows into thesuction side space 43 a of theexpander working chamber 43 and thesuction side space 63 a of thecompressor working chamber 63. Thus, a torque is generated in each of theexpander 4 and thecompressor 6. - When the
shaft 81 is in the range of θ=about 85° to about 95°, thecompressor suction port 6 a is opened but is in communication with thecompressor discharge port 6 b through thecompressor working chamber 63, and the working fluid leaks from thecompressor suction port 6 a to the compressor discharge port 26 b. Thus, no torque is generated in thecompressor 6. However, since theexpander suction port 4 a is opened and the high pressure working fluid flows into the suction side space of theexpander working chamber 63, a torque is generated in theexpander 4. - When the
shaft 81 is in the range of θ=about 95° to about 105°, thecompressor suction port 6 a is closed and no torque is generated in thecompressor 6, but theexpander suction port 4 a is opened and the high pressure working fluid flows into thesuction side space 63 a of thecompressor working chamber 63. Thus, a torque is generated in thecompressor 6. - When the
shaft 81 is in the range of θ=about 105° to about 140°, both of theexpander suction port 4 a and thecompressor suction port 6 a are opened and the high pressure working fluid flows into thesuction side space 43 a of theexpander working chamber 43 and thesuction side space 63 a of thecompressor working chamber 63. Thus, a torque is generated in each of theexpander 4 and thecompressor 6. - When the
shaft 81 is in the range of θ=about 140° to 360°, theexpander suction port 4 a is closed and no torque is generated in theexpander 4, but thecompressor suction port 6 a is opened and the high pressure working fluid flows into thesuction side space 63 a of thecompressor working chamber 63. Thus, a torque is generated thecompressor 6. - As described above, in the present embodiment, the
fluid machine 8A, which has no driving device, can self-start without fail at the start of the refrigeration cycle apparatus 1 owing only to the pressure of the working fluid. Therefore, the reliability of the refrigeration cycle apparatus 1 can be increased. - Next, a
fluid machine 8B according toEmbodiment 2 of the present invention will be described with reference toFIG. 8 andFIG. 9 . In the present embodiment, the same components as those in Embodiment 1 are designated by the same reference numerals, and the descriptions thereof are omitted. In addition, since a refrigeration cycle apparatus using thefluid machine 8B is the same as the refrigeration cycle apparatus 1 shown inFIG. 1 , the description thereof also is omitted. - <Configuration of Fluid Machine>
- The
fluid machine 8B of the present embodiment is different from thefluid machine 8A of Embodiment 1 in that thesuction pipe 84 is connected to thesecond closing member 66, and thecompressor 6 is a fluid pressure motor compressor and does not have the discharge valve 68 (seeFIG. 2 ). That is, thecompressor 6 increases the pressure of the working fluid without changing the volume of the working fluid. - Specifically, in the
second closing member 66, thecompressor suction port 6 a is provided so as to be exposed only to thesuction side space 63 a of thecompressor working chamber 63 and thecompressor discharge port 6 b is provided so as to be exposed only to thedischarge side space 63 b of thecompressor working chamber 63. Both of thecompressor suction port 6 a and thecompressor discharge port 6 b extend in the axial direction of theshaft 81. Moreover, asuction passage 6 c that brings an upper end of thecompressor suction port 6 a into communication with thesuction pipe 84 and adischarge passage 6 d that brings an upper end of thecompressor discharge port 6 b into communication with thedischarge pipe 85 are formed in thesecond closing member 66. - More specifically, the
compressor suction port 6 a and thecompressor discharge port 6 b extend from a vicinity of thecompressor partition member 64 so as to be gradually away from the inner circumferential surface of thecompressor cylinder 61. Outer edges of thecompressor suction port 6 a and thecompressor discharge port 6 b (edges on a side of the inner circumferential surface of the compressor cylinder 61) each are formed in an arc shape that coincides with the outer circumferential surface of thecompressor piston 62 when thecompressor piston 62 is present at the top dead center. That is, thecompressor suction port 6 a is completely closed by thecompressor piston 63 only during a short period of time after thecompressor piston 62 is present at the top dead center, and thecompressor discharge port 6 b is completely closed by thecompressor piston 63 only during a short period of time before thecompressor piston 62 is present at the top dead center. - Moreover, in the present embodiment, the relationship between the eccentric orientation of the first
eccentric portion 81 b of theshaft 81 and the eccentric orientation of the second eccentric portion 82 b of theshaft 81, and the relationship between the position of theexpander partition member 44 and the position of thecompressor partition member 64 are the same as in Embodiment 1. - The
compressor suction port 6 a and thecompressor discharge port 6 b do not necessarily have to be provided in thesecond closing member 66, and one or both of them may be provided in thefirst closing member 49. - <Operation of
Fluid Machine 8B> - Next, the operation of the
fluid machine 8A during the steady operation will be described with reference toFIGS. 10A to 10C andFIGS. 11A to 11C . In these figures, the rotation angle θ of theshaft 81 when theexpander piston 42 is present at the top dead center is defined as 0°. Since the operation of theexpander 4 is the same as in Embodiment 1, the description thereof is omitted. - As shown in
FIG. 10C andFIGS. 11A to 11C , thecompressor suction port 6 a is completely closed by thecompressor piston 62 when theshaft 81 rotates from the point of 90° to the point of about 95°. After theshaft 81 rotates about 95°, thecompressor suction port 6 a is opened gradually and the low pressure working fluid from theevaporator 5 is drawn into thesuction side space 63 a of thecompressor working chamber 63 through thecompressor suction port 6 a. Then, as shown inFIGS. 10A and 11B , thecompressor suction port 6 a is closed gradually after thecompressor piston 62 rotates about 360°. When theshaft 81 rotates 90° again, the suction process is completed and thesuction side space 63 a of thecompressor working chamber 63 shifts to thedischarge side space 63 b. After theshaft 81 rotates 90°, thecompressor discharge port 6 b is opened gradually, and the working fluid in thedischarge side space 63 b is discharged toward themain compressor 2 through thecompressor discharge port 6 b. Such extrusion of the working fluid by thecompressor piston 62 increases the pressure of the working fluid. Thecompressor discharge port 63 b is closed gradually after theshaft 81 rotates about 300°, and is completely closed by thecompressor piston 62 when theshaft 81 rotates from the point of about 85° to the point of about 90°. - <Actions and Effects of the Present Embodiment>
- In the present embodiment, the
expander suction port 4 a is opened during the period of time when θ=0° to about 140°, and theexpander suction port 4 a is closed during the period of time when θ=about 140° to 360°, as described above. In contrast, thecompressor suction port 6 a is closed during the period of time when θ=90° to about 95°, and thecompressor suction port 6 a is opened during the periods of time when θ=0° to 90° and θ=about 95° to 360°. That is, theexpander suction port 4 a is closed after thecompressor suction port 6 a is brought into communication with thesuction side space 63 a of thecompressor working chamber 63, and theexpander suction port 4 a is opened before thecompressor suction port 6 a is closed. - As described in the section <Operation of refrigeration cycle apparatus>, since, at the start of the refrigeration cycle apparatus 1, the
main compressor 2 is started in the state in which thesecond bypass valve 94 is opened and the compressorupstream valve 71 is closed, high pressure-low pressure differences occur between the working fluid in the flow passage on the side of the suction mouth of theexpander 4 and the working fluid in the flow passage on the side of the discharge mouth of theexpander 4, and between the working fluid in the flow passage on the side of the suction mouth of thecompressor 6 and the working fluid in the flow passage on the side of the discharge mouth of thecompressor 6, respectively. In other words, the flow passage of thefluid machine 8A upstream of theexpander suction port 4 a through thesuction pipe 82 and the flow passage of thefluid machine 8A upstream of thecompressor suction port 6 a through thesuction pipe 84 are filled with the high pressure working fluid. - In the present embodiment, since the
fluid machine 8A is configured as described above, at least one of theexpander suction port 4 a and thecompressor suction port 6 a always is opened and the high pressure working fluid always flows into at least one of thesuction side space 43 a of theexpander working chamber 43 and thesuction side space 63 a of thecompressor working chamber 63 no matter what angular position theshaft 81 of thefluid machine 8A takes at the start of the refrigeration cycle apparatus 1. Therefore, no matter in what state thefluid machine 8A is stopped, a torque for rotating theshaft 81 can be generated in one or both of theexpander 4 and thecompressor 6, making it possible for thefluid machine 8A to self-start owing to the pressure of the working fluid. - Specifically, when the
shaft 81 is in the range of θ=0° to 90°, both of theexpander suction port 4 a and thecompressor suction port 6 a are opened and the high pressure working fluid flows into thesuction side space 43 a of theexpander working chamber 43 and thesuction side space 63 a of thecompressor working chamber 63. Thus, a torque is generated in each of theexpander 4 and thecompressor 6. - When the
shaft 81 is in the range of θ=90° to about 95°, thecompressor suction port 6 a is closed and no torque is generated in thecompressor 6, but theexpander suction port 4 a is opened and the high pressure working fluid flows into thesuction side space 63 a of thecompressor working chamber 63. Thus, a torque is generated in thecompressor 6. - When the
shaft 81 is in the range of θ=about 95° to about 140°, both of theexpander suction port 4 a and thecompressor suction port 6 a are opened and the high pressure working fluid flows into thesuction side space 43 a of theexpander working chamber 43 and thesuction side space 63 a of thecompressor working chamber 63. Thus, a torque is generated in each of theexpander 4 and thecompressor 6. - When the
shaft 81 is in the range of θ=about 140° to 360°, theexpander suction port 4 a is closed and no torque is generated in theexpander 4, but thecompressor suction port 6 a is opened and the high pressure working fluid flows into thesuction side space 63 a of thecompressor working chamber 63. Thus, a torque is generated in thecompressor 6. - As described above, in the present embodiment, the
fluid machine 8A, which has no driving device, can self-start without fail at the start of the refrigeration cycle apparatus 1 owing only to the pressure of the working fluid. Therefore, the reliability of the refrigeration cycle apparatus 1 can be increased. - In the embodiments mentioned above, the
rotor plate 48 constitutes the drawing control mechanism in which theexpander suction port 4 a is opened and closed as theshaft 81 rotates. However, the drawing control mechanism of the present invention is not limited to this and drawing control mechanisms with various structures can be employed. For example, a drawing control mechanism with the structure disclosed in Patent Literature 1 may be employed, or a drawing control mechanism in which an arc groove is provided in an upper surface of the firsteccentric portion 81 b of theshaft 81 and a communication groove that brings the arc groove into communication with thesuction side space 43 a of theexpander working chamber 43 is provided in the lower surface of thefirst closing member 49 may be employed. - The present invention surely can realize the self-starting of the fluid machine. The present invention is useful particularly for refrigeration cycle apparatuses using the fluid machine as a power recovery system.
Claims (10)
1. A fluid machine comprising:
an expander that expands a working fluid drawn through an expander suction port and discharges the working fluid through an expander discharge port so as to recover power from the working fluid;
a compressor that increases a pressure of the working fluid drawn through a compressor suction port and discharges the working fluid through a compressor discharge port; and
a shaft that couples the expander to the compressor so that the compressor is driven by the power recovered by the expander,
wherein the expander suction port and the compressor suction port are opened and closed as the shaft rotates, and
the expander suction port is opened during a period of time when the compressor suction port is closed, and the compressor suction port is opened and maintained out of communication with the compressor discharge port during a period of time when the expander suction port is closed.
2. The fluid machine according to claim 1 ,
wherein the shaft has a first eccentric portion for the expander and a second eccentric portion for the compressor,
the compressor includes a compressor piston into which the second eccentric portion is fitted, a compressor cylinder accommodating the compressor piston, and a compressor partition member partitioning a compressor working chamber formed between the compressor piston and the compressor cylinder into a suction side space and a discharge side space, and
within a period of time when the expander suction port is opened, the compressor piston passes a top dead center at which a sliding point of the compressor piston sliding on an inner circumferential surface of the compressor cylinder coincides with the compressor partition member.
3. The fluid machine according to claim 2 ,
wherein the expander includes an expander piston into which the first eccentric portion is fitted, an expander cylinder accommodating the expander piston, and an expander partition member partitioning an expander working chamber formed between the expander piston and the expander cylinder into a suction side space and a discharge side space, and
0.25θo≦βv−βc≦0.75θo is satisfied where, when a rotation direction of the shaft is defined as positive, βc (−180°<βc≦180°) indicates a phase difference of an eccentric orientation of the second eccentric portion with respect to an eccentric orientation of the first eccentric portion, βv (−180°<βc≦180°) indicates a phase difference of a position of the compressor partition member with respect to a position of the expander partition member, and further θo indicates a rotation angle of the shaft during the period of time when the expander suction port is opened.
4. The fluid machine according to claim 2 ,
wherein the compressor suction port is provided in the compressor cylinder and opens on the inner circumferential surface of the compressor cylinder, and
the expander suction port is closed after the compressor suction port is brought into communication with the suction side space of the compressor working chamber, and the expander suction port is opened before the suction side space of the compressor working chamber is brought into communication with the compressor discharge port.
5. The fluid machine according to claim 4 , wherein the compressor further includes a discharge valve for opening and closing the compressor discharge port owing to a pressure of the discharge side space of the compressor working chamber.
6. The fluid machine according to claim 2 ,
wherein the compressor further includes an inner closing member for closing the compressor working chamber from a side of the expander and an outer closing member for closing the compressor working chamber from a side opposite to the expander,
the compressor suction port is provided in the inner closing member or the outer closing member so as to be exposed only to the suction side space of the compressor working chamber, and
the expander suction port is closed after the compressor suction port is brought into communication with the suction side space of the compressor working chamber, and the expander suction port is opened before the compressor suction port is closed.
7. The fluid machine according to claim 6 , wherein the compressor discharge port is provided in the inner closing member or the outer closing member so as to be exposed only to the discharge side space of the compressor working chamber.
8. The fluid machine according to claim 3 , wherein the expander further includes a drawing control mechanism for opening and closing the expander suction port as the shaft rotates.
9. The fluid machine according to claim 8 ,
wherein the expander further includes an inner closing member for closing the expander working chamber from a side of the compressor and an outer closing member for closing the expander working chamber from a side opposite to the compressor,
the expander suction port is provided in the inner closing member or the outer closing member so as to penetrate through the inner closing member or the outer closing member, and
the drawing control mechanism is a rotor plate that is attached to the shaft so as to rotate while being in contact with a surface of the inner closing member or the outer closing member opposite to the expander working chamber and that has a large diameter portion for blocking the expander suction port and a small diameter portion for exposing the expander suction port.
10. A refrigeration cycle apparatus using the fluid machine according to claim 1 , comprising:
a working fluid circuit through which a working fluid circulates, the working fluid circuit including a main compressor for compressing the working fluid, a radiator for radiating heat from the compressed working fluid, the expander for expanding the working fluid that has flowed out of the radiator, an evaporator for evaporating the expanded working fluid, and the compressor for increasing a pressure of the working fluid that has flowed out of the evaporator and supplying the working fluid to the main compressor; and
a bypass passage linking a portion between the main compressor and the radiator or a portion between the radiator and the expander to a portion between the evaporator and the compressor in the working fluid circuit.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
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JP2010-104775 | 2010-04-30 | ||
JP2010104775 | 2010-04-30 | ||
PCT/JP2011/002050 WO2011135779A1 (en) | 2010-04-30 | 2011-04-06 | Fluid machine and refrigeration cycle apparatus |
Publications (1)
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US20120131949A1 true US20120131949A1 (en) | 2012-05-31 |
Family
ID=44861108
Family Applications (1)
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US13/257,485 Abandoned US20120131949A1 (en) | 2010-04-30 | 2011-04-06 | Fluid machine and refrigeration cycle apparatus |
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US (1) | US20120131949A1 (en) |
JP (1) | JPWO2011135779A1 (en) |
CN (1) | CN102395759A (en) |
WO (1) | WO2011135779A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110247358A1 (en) * | 2008-12-22 | 2011-10-13 | Panasonic Corporation | Refrigeration cycle apparatus |
US20150322790A1 (en) * | 2013-01-25 | 2015-11-12 | Beijing Rostar Technology Co. Ltd., | Rotation device and rotor compressor and fluid motor having the same |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
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CN104564678B (en) * | 2013-10-28 | 2017-06-30 | 珠海格力节能环保制冷技术研究中心有限公司 | Expansion compressor device and the air-conditioner with it |
CN105179020B (en) * | 2014-05-26 | 2017-11-21 | 珠海格力节能环保制冷技术研究中心有限公司 | Expansion machinery suction control device |
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US5741120A (en) * | 1995-06-07 | 1998-04-21 | Copeland Corporation | Capacity modulated scroll machine |
US20060165542A1 (en) * | 2002-12-11 | 2006-07-27 | Katsumi Sakitani | Volume expander and fluid machine |
US20070154328A1 (en) * | 2003-05-13 | 2007-07-05 | Lg Electronics Inc. | Rotary compressor |
JP2007332819A (en) * | 2006-06-13 | 2007-12-27 | Hitachi Appliances Inc | Displacement fluid machine |
EP2077426A1 (en) * | 2006-10-25 | 2009-07-08 | Panasonic Corporation | Refrigeration cycle device and fluid machine used for the same |
JP2009204201A (en) * | 2008-02-27 | 2009-09-10 | Panasonic Corp | Refrigeration cycle device |
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JP4976970B2 (en) * | 2007-09-27 | 2012-07-18 | パナソニック株式会社 | Refrigeration cycle equipment |
-
2011
- 2011-04-06 JP JP2011533471A patent/JPWO2011135779A1/en not_active Withdrawn
- 2011-04-06 CN CN2011800017666A patent/CN102395759A/en active Pending
- 2011-04-06 US US13/257,485 patent/US20120131949A1/en not_active Abandoned
- 2011-04-06 WO PCT/JP2011/002050 patent/WO2011135779A1/en active Application Filing
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US5741120A (en) * | 1995-06-07 | 1998-04-21 | Copeland Corporation | Capacity modulated scroll machine |
US20060165542A1 (en) * | 2002-12-11 | 2006-07-27 | Katsumi Sakitani | Volume expander and fluid machine |
US20070154328A1 (en) * | 2003-05-13 | 2007-07-05 | Lg Electronics Inc. | Rotary compressor |
JP2007332819A (en) * | 2006-06-13 | 2007-12-27 | Hitachi Appliances Inc | Displacement fluid machine |
EP2077426A1 (en) * | 2006-10-25 | 2009-07-08 | Panasonic Corporation | Refrigeration cycle device and fluid machine used for the same |
JP2009204201A (en) * | 2008-02-27 | 2009-09-10 | Panasonic Corp | Refrigeration cycle device |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
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US20110247358A1 (en) * | 2008-12-22 | 2011-10-13 | Panasonic Corporation | Refrigeration cycle apparatus |
US20150322790A1 (en) * | 2013-01-25 | 2015-11-12 | Beijing Rostar Technology Co. Ltd., | Rotation device and rotor compressor and fluid motor having the same |
US10215025B2 (en) * | 2013-01-25 | 2019-02-26 | Beijing Rostar Technology Co. Ltd. | Rotation device and rotor compressor and fluid motor having the same |
Also Published As
Publication number | Publication date |
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JPWO2011135779A1 (en) | 2013-07-18 |
WO2011135779A1 (en) | 2011-11-03 |
CN102395759A (en) | 2012-03-28 |
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Owner name: PANASONIC CORPORATION, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:WADA, MASANOBU;OGATA, TAKESHI;SHIOTANI, YU;REEL/FRAME:027266/0881 Effective date: 20110804 |
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STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO PAY ISSUE FEE |