JP5615210B2 - Scroll compressor and refrigeration cycle apparatus including the same - Google Patents

Description

  The present invention relates to a scroll compressor that is mounted as a component of a refrigeration cycle apparatus such as an air conditioner, a water heater, or a refrigeration apparatus, and capable of capacity control, and a refrigeration cycle apparatus including the scroll compressor. .

  2. Description of the Related Art Conventionally, there is a scroll compressor that enables capacity control by an internal configuration of a sealed container (see, for example, Patent Document 1). In this scroll compressor, a capacity control mechanism is attached to the upper surface of the fixed scroll. When the low-pressure gas refrigerant is introduced into the control pressure introduction pipe constituting the capacity control mechanism, the switching valve (bypass valve) remains open and becomes unloaded. When is introduced, the switching valve is closed to enter a full load state. In the unloaded state, that is, in the open state of the switching valve, the gas refrigerant is discharged to the low pressure chamber in the shell through the communication hole (return hole) for the stroke volume outside the communication hole (bypass port). The stroke volume is smaller than in the case of. Generally, full load / unload switching is performed by controlling an electromagnetic valve or the like in the refrigerant circuit.

  In addition, there is a scroll compressor in which, for example, liquid refrigerant in a liquid receiver constituting a refrigerant circuit is injected into an intermediate pressure portion in the course of compression and evaporated to cool the compressor and to control capacity. (For example, refer to Patent Document 2). Also in this scroll compressor, a capacity control mechanism (injection flow path) is attached to the upper surface of the fixed scroll.

Japanese Unexamined Patent Publication No. 2000-161263 (page 5-6, FIG. 1) Japanese Patent Laid-Open No. 11-159479 (page 5, FIGS. 7-8)

  In the configuration of the scroll compressor as described in Patent Document 1 and Patent Document 2, the capacity control pipe and the injection flow path are individually attached to the fixed scroll. The number of man-hours and assembly man-hours increased. If it does so, it will be complicated and the cost corresponding to those increase will be needed, and it will be expected that the cost will rise.

  Further, in the configuration of the scroll compressor as described in Patent Document 2, since an electromagnetic valve or the like for controlling the injection amount is installed outside the compressor, the injection flow path is always connected to the compression chamber. The communication was in a state of communication, and the dead volume in compression increased. As a result, there is a possibility that the operation loss is increased.

  The present invention has been made to cope with the above-described problems. A scroll compressor that simplifies a capacity control mechanism to reduce costs and realizes reduction in operating loss and scroll compression thereof. It aims at providing the refrigerating cycle device provided with the machine.

  A scroll compressor according to the present invention includes a fixed scroll and an orbiting scroll, and a compression mechanism unit that compresses refrigerant sucked into a compression chamber when the orbiting scroll is rotationally driven with respect to the fixed scroll. A drive mechanism section for driving the orbiting scroll; a closed container that houses the compression mechanism section and the drive mechanism section; and a pressure introduction pipe for control that introduces refrigerant into the sealed container from the outside of the sealed container And a connecting pipe for introducing liquid refrigerant from the outside of the sealed container to the inside of the sealed container or returning the refrigerant being compressed to the outside of the sealed container, and the fixed scroll includes the control A capacity control space to which the pressure introduction pipe and the connection pipe are connected, an intermediate compression chamber in which refrigerant in the middle of compression exists, and a communication hole that connects the capacity control space are formed, and the capacity control space is formed. In, characterized in that installed a switching valve for opening and closing the communication hole by the pressure of the refrigerant introduced from said control pressure inlet pipe.

The refrigeration cycle apparatus according to the present invention includes the scroll compressor, a radiator that exchanges heat between the refrigerant discharged from the scroll compressor and a heat medium, a decompression mechanism that decompresses the refrigerant flowing out of the radiator, And a refrigeration cycle in which an evaporator that exchanges heat between the refrigerant decompressed by the decompression mechanism and the heat medium is connected by piping, a flow path between the radiator and the decompression mechanism, and compression in the scroll compressor and injection circuit for connecting the compression chamber in the process step, and the scroll compressor control valve installed in the control pressure introduction pipe for introducing the refrigerant into the closed vessel, the interior of the sealed container of the scroll compressor An injection control valve installed in one pipe branched from a connecting pipe for introducing liquid refrigerant or returning the refrigerant in the middle of compression to the outside of the sealed container; and the connection A capacity control valve installed in the other pipe branched from the control valve, and the injection control mode executed by controlling the control valve, the injection control valve, and the capacity control valve, the first capacity A control mode and a second capacity control mode, wherein the injection operation mode is executed by closing the control valve, opening the injection control valve, and closing the capacity control valve; The control mode is executed by opening the control valve, closing the injection control valve, and closing the displacement control valve. In the second displacement control mode, the control valve is closed and the injection control valve is closed. This is performed by opening the capacity control valve.

  According to the scroll compressor according to the present invention, the capacity control means and the refrigerant injection means can be configured by a common circuit, the number of parts, the number of machining processes, the number of assembly processes can be reduced, and the cost can be reduced. it can.

  According to the refrigeration cycle apparatus according to the present invention, since the above-described compressor is provided as one of the components of the refrigeration cycle, high-efficiency operation can be maintained over a wide range.

It is a lineblock diagram showing roughly the example of composition of the scroll compressor concerning an embodiment of the invention. It is a top view which shows roughly the state which looked at the fixed scroll of the scroll compressor which concerns on embodiment of this invention from the top. It is a partial block diagram which shows roughly the structural example of the scroll compressor provided with the capacity | capacitance control mechanism which exists conventionally. It is a partial block diagram which shows roughly the structural example of the scroll compressor which can be injected conventionally. It is explanatory drawing for demonstrating the relationship between the operation control mode of a compressor, and the state of each control valve. It is a circuit block diagram which shows roughly the refrigerant circuit structure of the refrigerating-cycle apparatus which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram schematically showing a configuration example of a scroll compressor (hereinafter referred to as a compressor 100) according to an embodiment of the present invention. FIG. 2 is a plan view schematically showing the fixed scroll 1 as viewed from above. Based on FIG.1 and FIG.2, the structure and operation | movement of the compressor 100 are demonstrated. In FIG. 1, the refrigerant flow is indicated by a broken line. Moreover, in FIG. 1, the flow of refrigeration oil is represented by a solid line arrow.

  The compressor 100 is a compressor using a scroll method in which a compression rate is determined by a scroll shape. The compressor 100 is a component of a refrigeration cycle apparatus such as a refrigerator, a freezer, a vending machine, an air conditioner, a refrigeration apparatus, or a water heater, and sucks refrigerant that circulates through the refrigeration cycle and compresses the refrigerant. Thus, it is discharged in a high temperature and high pressure state. In addition, in the following drawings including FIG. 1, the relationship of the size of each component may be different from the actual one. Further, in the following drawings including FIG. 1, the same reference numerals denote the same or equivalent parts, and this is common throughout the entire specification. Furthermore, the forms of the constituent elements shown in the entire specification are merely examples, and are not limited to these descriptions.

  The compressor 100 is configured by housing a compression mechanism unit 50 and a drive mechanism unit 60 in a shell (sealed container) 14 that is a pressure vessel. The compression mechanism unit 50 is disposed on the upper side of the shell 14, and the drive mechanism unit 60 is disposed on the lower side of the shell 14. The bottom of the shell 14 is an oil sump 17 that stores the refrigeration oil. Connected to the shell 14 are a suction pipe 15 that takes in an external refrigerant into the shell 14 and a discharge pipe 16 that discharges the compressed refrigerant out of the shell 14.

  Further, a connecting pipe 26 for injecting refrigerant is connected to the shell 14 in the intermediate compression chamber 4a in the course of compression (the formation position of the intermediate compression chamber 4a may be arbitrarily determined by the formation position of the communication hole 23). ing. The connection pipe 26 communicates with a capacity control space 30 formed in the fixed scroll 1 described later. Further, a control pressure introducing pipe 25 for taking in the refrigerant from the outside of the shell 14 is connected to the shell 14. The control pressure introducing pipe 25 communicates with the capacity control space 30. The connecting pipe 26 and the control pressure introducing pipe 25 are attached to the shell 14 by brazing, welding means, or the like. Further, the switching valve 24 is fixed to the capacity control space 30 with a fixing member such as a bolt. The switching valve 24 is biased upward by a spring or the like.

  The control pressure introduction pipe 25 extends outside the compressor 100 and is connected to a part of the refrigeration cycle. A control valve 27 is installed in the control pressure introduction pipe 25 outside the compressor 100. The connecting pipe 26 extends outside the compressor 100 and branches and then connects to a part of the refrigeration cycle. An injection control valve 28 and a capacity control valve 29 are installed in each branch pipe of the connection pipe 26. The control valve 27, the injection control valve 28, and the capacity control valve 29 are composed of electromagnetic valves or the like, and are controlled to open / close by a control device (not shown) so that the refrigerant may or may not be conducted. is there.

  The compression mechanism portion 50 is driven by the drive mechanism portion 60 and has a function of compressing the refrigerant gas sucked from the suction pipe 15 and discharging it to the discharge space 31 in the shell 14 through the discharge port 32. The compression mechanism unit 50 is generally configured by a fixed scroll 1, a swinging scroll 2, and an Oldham joint 6. The discharge space 31 is formed in an upper space inside the compressor 100 and is a high-pressure space. The refrigerant gas discharged into the discharge space 31 is discharged to the outside of the compressor 100 from the discharge pipe 16 communicating with the discharge space 31.

  The fixed scroll 1 is fixed to a frame 5 fixedly supported in the shell 14 by bolts or the like (not shown). Further, the fixed scroll 1 includes an end plate 1a and a wrap portion 1b that is a spiral projection having an involute curve shape that is erected on one surface of the end plate 1a (for example, a lower surface of the paper). Further, a discharge port 32 is formed at the center of the fixed scroll 1 to discharge the compressed and high-pressure refrigerant gas. On the upper surface of the end plate 1a of the fixed scroll 1 (surface opposite to the surface on which the wrap portion 1b is formed), the above-described capacity control space 30 is formed. The capacity control space 30 is covered with a cover 35 attached to the upper surface of the end plate 1 a of the fixed scroll 1.

  The end plate 1a of the fixed scroll 1 is formed with a communication hole 23 that allows the capacity control space 30 and the intermediate compression chamber 4a to communicate with each other. The communication holes 23 are preferably formed at two places as shown in FIG. Further, a connection hole 23 a for connecting the two communication holes 23 is formed inside the end plate 1 a of the fixed scroll 1. The capacity control space 30 may be formed with a pedestal 1c for fixing the switching valve 24 in advance. For convenience, the communication hole 23 that directly communicates with the capacity control space 30 will be referred to as a communication hole 23b.

  The orbiting scroll 2 performs a revolving orbiting movement without rotating with respect to the fixed scroll 1 by the Oldham joint 6. The orbiting scroll 2 includes an end plate 2a and a wrap portion 2b that is a spiral protrusion having an involute curve shape that is erected on one surface of the end plate 2a (the upper surface in the drawing). A hollow cylindrical oscillating scroll boss 2c is formed at a substantially central portion of a surface (hereinafter referred to as a thrust surface) opposite to the surface on which the wrap portion 2b of the oscillating scroll 2 is formed. An eccentric pin portion 3a provided at the upper end of a crankshaft 3 described later is fitted (engaged) with the swing scroll boss portion 2c.

  The fixed scroll 1 and the orbiting scroll 2 are fitted in the shell 14 so that the wrap portion 1b and the wrap portion 2b are engaged with each other. And between the lap | wrap part 1b and the lap | wrap part 2b, the compression chamber 4 from which a volume changes relatively is formed. The Oldham coupling 6 is disposed on the thrust surface of the orbiting scroll 2 and functions to prevent the rotation motion during the eccentric orbiting motion of the orbiting scroll 2. In other words, the Oldham joint 6 functions to prevent the orbiting scroll 2 from rotating and to enable a revolving orbiting motion.

  The drive mechanism unit 60 functions to drive the orbiting scroll 2 in order to compress the refrigerant gas by the compression mechanism unit 50. In other words, the driving mechanism 60 drives the orbiting scroll 2 via the crankshaft 3 so that the refrigerant gas is compressed by the compression mechanism 50. The drive mechanism 60 is roughly configured by a motor / rotor 9 fixed to the crankshaft 3 by press-fitting or the like, and a motor / stator 13 fixedly held by the shell 14. The motor / rotor 9 is fixed to the crankshaft 3 and is rotationally driven when the energization of the motor / stator 13 is started to rotate the crankshaft 3. The outer peripheral surface of the motor / stator 13 is fixedly supported on the shell 14 by shrink fitting or the like.

  A motor chamber upper space 21 and a motor chamber lower space 22 are formed above and below the drive mechanism 60. The second balancer 11 is attached to the lower surface of the motor / rotor 9 (the surface of the motor / rotor 9 located in the motor chamber lower space 22). The second balancer 11 has a function of rotating together with the motor / rotor 9 to obtain a mass balance (static and dynamic balance) with respect to the rotation. The second balancer 11 is attached to the lower surface of the motor / rotor 9 with screws or the like.

  The crankshaft 3 may be configured by selecting a material that has rigidity capable of securing an allowable deflection amount against an acting gas load, has good machinability, and can reduce costs. An upper end portion of the crankshaft 3 is formed with an eccentric pin portion 3a that is rotatably fitted to the swing scroll boss portion 2c of the swing scroll 2. In addition, an oil supply passage 3 b serving as a passage for refrigerating machine oil stored in the oil reservoir 17 is formed inside the crankshaft 3. By doing so, the refrigeration oil accumulated in the oil sump 17 can be sucked up by the oil pump 18 driven as the crankshaft 3 rotates and supplied to the compression mechanism 50.

  A first balancer 10 is attached to a portion of the crankshaft 3 located in the motor chamber upper space 21. The first balancer 10 has a function of rotating together with the crankshaft 3 and obtaining a mass balance (static and dynamic balance) with respect to this rotation. The first balancer 10 is covered with a balancer cover 12 attached to the lower surface of the frame 5. The first balancer 10 is attached to the crankshaft 3 with screws or the like.

  An outer peripheral surface of the shell 14 is fixed to the inner peripheral surface of the shell 14 by shrink fitting, welding, or the like, so that the fixed scroll 1 is supported, and the crankshaft 3 can be rotated through a through hole formed in the center portion. A supporting frame 5 is installed. This frame 5 also has a function of rotatably supporting the orbiting scroll 2. A main bearing 36 that rotatably supports the crankshaft 3 is provided in the through hole of the frame 5. The frame 5 is installed above the shell 14 so as to support the upper part of the crankshaft 3. The frame 5 is formed with a suction port 5 a that guides the refrigerant gas present in the motor chamber upper space 21 to the compression chamber 4.

  The shell 14 has an outer peripheral surface fixed to the inner peripheral surface of the shell 14 by shrink fitting, welding, or the like, and a second frame 19 that rotatably supports the crankshaft 3 through a through hole formed in the center portion. Is installed. A bearing 20 that rotatably supports the crankshaft 3 is provided in the through hole of the second frame 19. The second frame 19 is installed below the shell 14 so as to support the lower portion of the crankshaft 3. The second frame 19 is provided with a positive displacement oil pump 18. The oil pump 18 is driven by the crankshaft 3 to suck up the refrigerating machine oil stored in the oil reservoir 17 and supply it to the compression mechanism 50 and each bearing through the oil supply passage 3b.

  An oil drain pipe 7 for returning the refrigeration oil to the oil sump 17 is provided on the outer peripheral side of the drive mechanism 60. The oil drain pipe 7 is attached to the oil drain pipe fixing plate 8 by brazing or welding means. The oil drain pipe fixing plate 8 is attached to the lower surface of the frame 5 with bolts or the like. A balancer cover 12 is attached to the lower surface of the frame 5 with bolts or the like.

The operation of the compressor 100 will be briefly described.
[basic action]
When the motor / stator 13 is energized, the motor / rotor 9 rotates by receiving a rotational force from a rotating magnetic field generated by the motor / stator 13. Accordingly, the crankshaft 3 fixed to the motor / rotor 9 and supported by the main bearing of the frame 5 and the bearing 20 of the second frame 19 is rotationally driven. The rotational movement of the crankshaft 3 is transmitted to the orbiting scroll 2 via the eccentric pin portion 3a and the orbiting scroll boss portion 2c of the crankshaft 3. At this time, the orbiting scroll 2 is revolved by the Oldham joint 6 so that its rotation is restricted. Here, the orbiting scroll 2 performs an eccentric revolving motion, and the static balance and the dynamic balance are performed by the first balancer 10 and the second balancer 11.

  As the drive mechanism 60 is driven, the refrigerant is sucked into the shell 14 from the suction pipe 15 to cool the drive mechanism 60, and then formed by the wrap portion 2 b of the orbiting scroll 2 and the wrap portion 1 b of the fixed scroll 1. It is taken into the outer compression chamber 4 through the suction port 5a (broken line arrow shown in FIG. 1). The refrigerant taken into the compression chamber 4 moves to the center of the orbiting scroll 2 by the orbiting motion of the orbiting scroll 2 and is compressed by further reducing the volume. At this time, the compression ratio is geometrically determined by the shape of the scroll wrap. Further, a capacity control space 30 is communicated with the intermediate compression chamber 4 a in the course of compression moving to the center via the communication hole 23, and a connection pipe 26 is connected to the capacity control space 30.

  Then, the refrigerant gas compressed in the compression chamber 4 becomes a high pressure state, is discharged from the discharge port 32 formed in the fixed scroll 1, passes through the discharge space 31, and is discharged to the outside of the compressor 100. Is done. The compressed high-pressure refrigerant flows out of the shell 14 from the discharge pipe 16 and circulates in the refrigeration cycle. Thereafter, when the energization of the motor / stator 13 is stopped, the compressor 100 is stopped.

  FIG. 3 is a partial configuration diagram schematically showing a configuration example of a scroll compressor (hereinafter referred to as a compressor A) having a conventional capacity control mechanism. FIG. 4 is a partial configuration diagram schematically illustrating a configuration example of a conventional scroll compressor that can be injected (hereinafter referred to as a compressor B). Based on FIG.3 and FIG.4, the characteristic operation | movement of the compressor A and the compressor B is demonstrated. The same parts of the compressor A and the compressor B as the compressor 100 are denoted by “A” and “B”, respectively. In FIGS. 3 and 4, the refrigerant flow is indicated by broken-line arrows.

[Conventional capacity control operation]
In the compressor A, a capacity control mechanism that enables capacity control is mounted on the upper surface side of the fixed scroll 1A. This capacity control mechanism includes a communication hole 23A, a switching valve 24A, a control pressure introduction pipe 25A, and a control valve 27A installed in the control pressure introduction pipe 25A outside the compressor A. The switching valve 24A is pushed upward by a spring or the like. Therefore, when the low-pressure gas is introduced into the control pressure introduction pipe 25A, the switching valve 24A remains pushed up and enters an unloaded state (the discharge capacity is about 2/3 of the total capacity) (broken line arrow X shown in FIG. 3). ). On the other hand, when high-pressure gas is introduced into the control pressure introduction pipe 25A, the switching valve 24A is pushed down, and a full load state (discharge capacity is full capacity) is obtained.

  In the unloaded state, that is, in the state in which the switching valve 24A is opened (pushed up), the refrigerant gas corresponding to the stroke volume outside the communication hole 23A is discharged into the shell 14 through the communication hole (discharge hole) 23c. The stroke volume is smaller than when loading. Switching between full load / unload is performed by switching the introduction pressure by a control valve 27A such as an electromagnetic valve in the refrigerant circuit. Note that the communication hole 23 c is not formed in the fixed scroll 1 of the compressor 100. Therefore, in the compressor A, the injection control operation cannot be realized.

[Conventional injection control operation]
In the compressor B, a connecting pipe 26B for injecting refrigerant is connected to the intermediate compression chamber 4aB in the middle of compression. The connection pipe 26B is communicated with a communication hole 23B formed in the fixed scroll 1B. In this type of compressor B, the liquid refrigerant in the liquid receiver (for example, accumulator, receiver, etc.) in the refrigerant circuit is guided to the connecting pipe 26B, returned to the intermediate compression chamber 4aB, and evaporated to cause the compressor B. Cool down. Therefore, the capacity control operation cannot be realized in the compressor B. A capacity control space is not formed in the fixed scroll 1B of the compressor B.

From here, the operation control mode executed by the compressor 100 will be described in detail.
The compressor 100 includes a normal operation control mode, an injection control mode, a first capacity control mode, and a second capacity control mode as operation control modes, and can be executed according to conditions. FIG. 5 is an explanatory diagram for explaining the relationship between the operation control mode of the compressor 100 and the states of the control valves (the control valve 27, the injection control valve 28, and the capacity control valve 29).

[Normal operation control mode of compressor 100]
When executing the normal operation control mode, a control device (not shown) opens the control valve 27, closes the injection control valve 28, and closes the capacity control valve 29 simultaneously with the start of operation of the compressor 100. That is, the control device executes the normal operation control mode by introducing the high-pressure refrigerant to the control pressure introduction pipe 25 and applying the high-pressure refrigerant as the back pressure to the switching valve 24. Since the switching valve 24 is closed by the high-pressure refrigerant, the communication hole 23 is closed. As a result, the space between the intermediate compression chamber 4a and the connection pipe 26 is closed. That is, in the normal operation control mode, the compressor 100 is operated in a full load state.

[Injection control mode of compressor 100]
When the temperature of the compressor 100 rises, the control device closes the control valve 27, opens the injection control valve 28, and closes the capacity control valve 29. That is, the control device prevents the high-pressure refrigerant from being guided to the control pressure introduction pipe 25. Then, the switching valve 24 is opened because a high pressure is not applied as a back pressure. Therefore, the communication hole 23 is opened and communicates with the connection pipe 26 via the capacity control space 30. Then, the liquid refrigerant is supplied from the injection control valve 28 to the intermediate compression chamber 4a, where it is evaporated to cool the compressor 100.

[First capacity control mode of compressor 100 (full load control mode)]
When executing the first capacity control mode, the control device opens the control valve 27, opens the injection control valve 28, and closes the capacity control valve 29. That is, the control device executes the first capacity control mode by introducing the high-pressure refrigerant to the control pressure introduction pipe 25 and applying the high-pressure refrigerant to the switching valve 24 as a back pressure. Since the switching valve 24 is closed by the high-pressure refrigerant, the communication hole 23 is closed. As a result, the space between the intermediate compression chamber 4a and the connection pipe 26 is closed. That is, the refrigerant flowing into the intermediate compression chamber 4a is prevented from returning to the low pressure side of the refrigeration cycle through the connection pipe 26.

[Second capacity control mode of compressor 100 (light load control mode)]
On the other hand, when executing the second capacity control mode, the control device closes the control valve 27, closes the injection control valve 28, and opens the capacity control valve 29. That is, the control device prevents the high-pressure refrigerant from being guided to the control pressure introduction pipe 25. Then, the switching valve 24 is opened because a high pressure is not applied as a back pressure. Therefore, the communication hole 23 is opened, communicates with the connection pipe 26 through the capacity control space 30, and is opened to the low pressure side of the refrigeration cycle through the capacity control valve 29. Thereby, the refrigerant flowing into the intermediate compression chamber 4a is discharged to the low pressure side through the connection pipe 26, and a stroke volume smaller than that at the time of full load can be realized.

  According to the compressor 100 configured as described above, the normal operation control mode, the injection control mode, the first capacity is provided by including the communication hole 23, the switching valve 24, the control pressure introduction pipe 25, and the connection pipe 26. Either the control mode or the second capacity control mode can be executed. Therefore, the capacity control means and the refrigerant injection means can be configured by a common circuit, and the number of parts, the number of machining processes, the number of assembly processes can be reduced, the concept can be simplified, and the cost can be reduced. Further, according to the compressor 100, since the configuration in which the switching valve 24 is installed inside the compressor is adopted, the dead volume can be reduced compared to the configuration in which the switching valve is separately provided in any of the refrigeration cycles, It also reduces operating loss.

[Refrigeration cycle apparatus 200]
FIG. 6 is a circuit configuration diagram schematically showing the refrigerant circuit configuration of the refrigeration cycle apparatus 200 according to the embodiment of the present invention. The configuration and operation of the refrigeration cycle apparatus 200 will be described based on FIG. This refrigeration cycle apparatus 200 includes the above-described compressor 100 as one of the component devices constituting the refrigeration cycle, and is used for, for example, a refrigerator, a freezer, a vending machine, an air conditioner, a showcase, a heat pump water heater, and the like. Is. The refrigeration cycle apparatus 200 includes a compressor 100, a condenser (heat radiator) 202, a decompression mechanism 203, and an evaporator 204, which are connected by a pipe 205 to sequentially circulate the refrigerant.

  The compressor 100 basically compresses the refrigerant sucked from the suction pipe 15 into a high temperature / high pressure state and discharges it from the discharge pipe 16. The compressor 100 is configured by a capacity control type whose rotation speed can be controlled by an inverter, for example. The condenser 202 condenses and liquefies the refrigerant by exchanging heat between the refrigerant discharged from the compressor 100 and a heat medium such as air or water. The decompression mechanism 203 decompresses and expands the refrigerant that has flowed out of the condenser 202. The decompression mechanism 203 may be constituted by an electronic expansion valve or the like whose opening degree can be variably controlled, for example. The evaporator 204 performs heat exchange between the refrigerant decompressed by the decompression mechanism 203 and a heat medium such as air or water to evaporate the refrigerant.

  As shown in FIG. 6, the control pressure introduction pipe 25 is connected to the inlet side of the condenser 202 which is a part of the refrigeration cycle. The control pressure introduction pipe 25 is provided with the control valve 27 as described above. After branching outside the compressor 100, the connection pipe 26 is connected between the condenser 202 and the decompression mechanism 203, one of which is part of the refrigeration cycle, and the evaporator 204, which is part of the refrigeration cycle. Between the compressor 100 and the compressor 100. After branching, an injection control valve 28 is installed in the connecting pipe 26 connected between the condenser 202 and the pressure reducing mechanism 203. A capacity control valve 29 is installed in the connection pipe 26 connected between the evaporator 204 and the compressor 100 after being branched. The operations of the control valve 27, the injection control valve 28, and the capacity control valve 29 are as described above.

  The refrigeration cycle apparatus 200 is equipped with a control device (not shown) composed of a microcomputer or the like that can control the entire system. This control device has functions for performing drive frequency control of the compressor 100, opening control of the pressure reducing mechanism 203, opening control of the control valve 27, opening control of the injection control valve 28, opening / closing control of the capacity control valve 29, and the like. Have. The control device controls these actuators (for example, the compressor 100, the pressure reducing mechanism 203, the control valve 27, the injection control valve 28, the capacity control valve 29, etc.) and executes each operation control mode described above. .

In the refrigeration cycle apparatus 200, R410A, R407C, R404A, etc., which are HFC refrigerants having a generally used ozone depletion coefficient of zero, can be used as the refrigerant. Recently, R32 having a small global warming potential and a mixed refrigerant containing the same may be used. When R32 or carbon dioxide (CO ₂ ) is used as a refrigerant, the temperature of the refrigerant discharged from the compressor 100 is higher than that of R410A, R407C, and R404A, and the resin used as a sealing material in the refrigerant circuit Since the refrigerating machine oil may be deteriorated, according to the refrigeration cycle apparatus 200, the discharge temperature can be lowered using the injection mechanism.

The refrigerant flow during the basic operation of the refrigeration cycle apparatus 200 will be described.
The high-temperature and high-pressure gas refrigerant compressed by the compressor 100 flows into the condenser 202, dissipates heat by heat exchange with the heat medium supplied to the condenser 202, becomes high-pressure liquid refrigerant, and flows out of the condenser 202. . The high-pressure liquid refrigerant that has flowed out of the condenser 202 flows into the decompression mechanism 203 and is decompressed to become a low-pressure two-phase refrigerant or a low-pressure liquid refrigerant. The low-pressure refrigerant that has flowed out of the decompression mechanism 203 flows into the evaporator 204 and evaporates by heat exchange with the heat medium supplied to the evaporator 204 to become a low-pressure gas refrigerant and flows out of the evaporator 204. The low-pressure gas refrigerant that has flowed out of the evaporator 204 is sucked into the compressor 100 again.

  The injection mechanism has the effect of lowering the gas temperature during compression by injecting liquid refrigerant or gas refrigerant at a high pressure and a low temperature into the intermediate compression chamber 4a during compression in the compression process, that is, cooled by the condenser 202. There is. At the same time, injecting a high-pressure and high-density refrigerant increases the mass in the intermediate compression chamber 4a and increases the amount of refrigerant in the compressor 100.

  Also, in recent years, halogenated hydrocarbons having a carbon double bond in the composition such as HFO1234yf, HFO1234ze, and HFO1243zf, which are called Freon-based low GWP refrigerants, hydrocarbons such as propane and propylene, which are natural refrigerants, or When a mixture containing them is used as a refrigerant, it is necessary to increase the circulation amount of the refrigerant, which is a response to a large capacity compressor. With a large-capacity compressor, when operating with a small load, that is, when operating with a small amount of refrigerant circulation, it is possible to reduce the drive speed, but it is possible to supply the minimum required lubricating oil for each bearing The drive speed can only be reduced to the limit. Therefore, the second capacity control mode that is bypassed to the middle of the intermediate compression chamber 4a and the suction pipe 15 side of the compressor 100 is effective for reducing the refrigerant circulation amount.

  From here, the operation mode which the refrigerating cycle apparatus 200 performs is demonstrated in detail. The refrigeration cycle apparatus 200 can select and execute the above-described normal operation control mode, injection control mode, first capacity control mode, and second capacity control mode according to conditions.

An example of the switching of each operation mode performed by the refrigeration cycle apparatus 200 will be described.
(1) Normal Operation Control Mode In the refrigeration cycle apparatus 200, the operation is normally performed in the normal operation control mode including when the refrigeration cycle apparatus 200 is activated.

(2) Injection control mode This mode is operated at the time of high pressure differential operation (operation in which the difference between high pressure and low pressure is greater than or equal to a predetermined value), for example, during refrigeration / freezing or heating / hot water supply operation. Under such conditions, the low-pressure pressure is relatively low and the refrigerant circulation rate is reduced. At this time, in the refrigeration cycle apparatus 200, the drive rotational speed of the compressor 100 is increased to increase the refrigerant circulation amount, and the discharge temperature is increased due to the high compression ratio operation. Therefore, the refrigeration cycle apparatus 200 selects and executes the injection operation mode.

  In the injection operation mode, in order to prevent the discharged refrigerant temperature from the compressor 100 from exceeding 100 to 150 ° C., the intermediate compression chamber 4a in the middle of the compression process is supercharged with a refrigerant having a high density and a low temperature. By doing so, the discharge temperature and the refrigerant circulation amount can be optimally adjusted. In addition, what is necessary is just to detect the refrigerant | coolant temperature discharged from the compressor 100 with the temperature sensor (not shown) etc. which were attached to the vicinity of the discharge pipe 16.

(3) First capacity control mode When the required load is large (the required load is larger than a predetermined value set in advance), for example, a plurality of indoor units are connected to one outdoor unit. This is a mode that is operated when all indoor units are operated in a multi-air conditioner or the like. Therefore, the refrigeration cycle apparatus 200 selects and executes the first capacity control mode. By selecting the first capacity control mode, a full load operation can be performed, and it is possible to cope with a heavy load condition. The actuator control is the same as in the normal operation control mode.

(4) Second capacity control mode When the required load is very small (the required load is smaller than a predetermined value set in advance), for example, a plurality of indoor units for one outdoor unit This is a mode that is operated when only one indoor unit is operated in a multi air conditioner or the like to which is connected. Under such conditions, the compression ratio decreases, the relatively low pressure increases, and the refrigerant circulation rate increases. At this time, in the refrigeration cycle apparatus 200, the drive rotational speed of the compressor 100 is reduced in order to reduce the refrigerant circulation rate. However, the drive rotational speed of the compressor 100 can be reduced only to the limit that can supply the minimum necessary lubricating oil in each bearing of the compressor 100. Moreover, if the compressor 100 is stopped in order to avoid it, it is necessary to continue operation as much as possible because it takes a long time to start up or power consumption at the time of starting is large.

  Therefore, the refrigeration cycle apparatus 200 selects and executes the second capacity control mode. By selecting the second capacity control mode, the refrigerant is compressed from the middle of the intermediate compression chamber 4a. Even when the load is very small, the operation of the compressor 100 is continued and the refrigerant circulation amount is reduced. Will be able to.

  As described above, according to the refrigeration cycle apparatus 200 according to the embodiment of the present invention, since the compressor 100 is provided as one of the components of the refrigeration cycle, high-efficiency operation is maintained over a wide range. It becomes possible to do. That is, according to the refrigeration cycle apparatus 200, it is possible to easily obtain the optimum operation state corresponding to various loads.

  A temperature sensor and a pressure sensor that can detect the temperature and pressure of the refrigerant, the outside air temperature, the temperature of the shell 14 and the like are installed, and the control device may select the operation mode based on the information. . In addition, when using chlorofluorocarbon-based low GWP refrigerants such as R32, the discharge temperature is higher than that of conventional refrigerants, so it is possible to prevent temperature deterioration of seal materials, sliding members and refrigerator oil used in the refrigeration cycle. For this reason, it is necessary to prevent the discharge temperature from rising excessively in order to secure the sliding clearance. However, according to the refrigeration cycle apparatus 200, since the injection control mode is provided, a cold refrigerant is excessively introduced into the intermediate compression chamber 4a. Supply (injection) can be performed and excessive discharge temperature can be suppressed.

  In addition, when using chlorofluorocarbon-based low GWP refrigerants such as HFO1234yf and hydrocarbon-based natural refrigerants such as propane, in order to obtain refrigeration capacity, heating capacity, or efficiency equal to or higher than conventional ones, a wide range of refrigerant compression ratios are used. Although it is necessary to take a large amount of refrigerant circulation, the refrigeration cycle apparatus 200 is provided with the second capacity control mode, so that it is possible to reduce the pressure loss.

  1 fixed scroll, 1A fixed scroll, 1B fixed scroll, 1a end plate, 1b lap part, 1c pedestal, 2 swing scroll, 2a end plate, 2b wrap part, 2c swing scroll boss part, 3 crankshaft, 3a eccentric pin part, 3b Oil supply flow path, 4 compression chamber, 4a intermediate compression chamber, 4aB intermediate compression chamber, 5 frame, 5a suction port, 6 Oldham joint, 7 oil drain pipe, 8 oil drain pipe fixing plate, 9 motor rotor, 10 first balancer, 11 Second balancer, 12 Balancer cover, 13 Motor / stator, 14 Shell, 15 Suction pipe, 16 Discharge pipe, 17 Oil reservoir, 18 Oil pump, 19 Second frame, 20 Bearing, 21 Motor room upper space, 22 Motor room Lower space, 23 communication hole, 23A communication hole, 23B communication hole, 23a connection hole 23b communication hole, 23c communication hole, 24 switching valve, 24A switching valve, 25 control pressure introducing pipe, 25A control pressure introducing pipe, 26 connecting pipe, 26B connecting pipe, 27 control valve, 27A control valve, 28 injection control valve , 29 Capacity control valve, 30 Capacity control space, 31 Discharge space, 32 Discharge port, 35 Cover, 36 Main bearing, 50 Compression mechanism section, 60 Drive mechanism section, 100 Scroll compressor, 200 Refrigeration cycle apparatus, 202 Condenser, 203 Decompression mechanism, 204 Evaporator, 205 Pipe, A compressor, B compressor.

Claims (3)

A compression mechanism having a fixed scroll and an orbiting scroll, and compressing the refrigerant sucked into the compression chamber when the orbiting scroll is rotationally driven with respect to the fixed scroll;
A drive mechanism for driving the orbiting scroll;
A sealed container that houses the compression mechanism and the drive mechanism;
A control pressure introducing pipe for introducing a refrigerant into the sealed container from the outside of the sealed container;
A liquid pipe is introduced into the inside of the sealed container from the outside of the sealed container, or a connection pipe for returning the refrigerant being compressed to the outside of the sealed container,
For the fixed scroll,
A capacity control space to which the pressure introduction pipe for control and the connection pipe are connected; and
A communication hole that communicates the intermediate compression chamber in which the refrigerant in the middle of compression exists and the capacity control space is formed,
A scroll compressor, wherein a switching valve that opens and closes the communication hole by the pressure of a refrigerant introduced from the control pressure introduction pipe is installed in the capacity control space. The scroll compressor according to claim 1, a radiator that exchanges heat between the refrigerant discharged from the scroll compressor and a heat medium, a decompression mechanism that decompresses the refrigerant that has flowed out of the radiator, and the decompression mechanism A refrigeration cycle in which an evaporator for exchanging heat between the refrigerant decompressed in step 1 and the heat medium is connected by piping;
An injection circuit that connects a flow path between the radiator and the decompression mechanism and a compression chamber in the course of compression in the scroll compressor;
A control valve installed in a pressure introduction pipe for control for introducing a refrigerant into the sealed container of the scroll compressor;
An injection control valve installed in one pipe branched from a connecting pipe for introducing liquid refrigerant into the inside of the sealed container of the scroll compressor or returning the refrigerant being compressed to the outside of the sealed container;
A capacity control valve installed in the other pipe branched from the connection pipe,
An injection control mode executed by controlling the control valve, the injection control valve, and the capacity control valve, a first capacity control mode, and a second capacity control mode;
The injection operation mode is:
Executed by closing the control valve, opening the injection control valve, and closing the capacity control valve,
The first capacity control mode is:
It is executed by opening the control valve, closing the injection control valve, and closing the capacity control valve,
The second capacity control mode is:
The refrigeration cycle apparatus is executed by closing the control valve, closing the injection control valve, and opening the capacity control valve. When the operation in which the difference between the high pressure and the low pressure is greater than or equal to a predetermined value is required, the injection operation mode is executed,
The first capacity control mode is executed when a required load is larger than a predetermined value set in advance,
The refrigeration cycle apparatus according to claim 2, wherein the second capacity control mode is executed when a required load is smaller than a predetermined value set in advance.

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