JPWO2009087733A1 - Refrigeration cycle equipment and four-way valve - Google Patents

Abstract

It is an object of the present invention to reduce the number of driving devices that drive switching means for switching the fluid flow direction, and to realize a compact refrigeration cycle device and simplified control. Moreover, it aims at providing the four-way valve which does not require a drive device. In the refrigeration cycle apparatus according to the present invention, the main path formed by connecting the compressor 23, the first heat exchanger 25, the decompression path 22, and the second heat exchanger 26 by piping, and the position of the valve body are arranged. The flow path switched by the main four-way valve 24 by switching the internal flow path, switching the flow direction of the fluid flowing through the main path, and the main four-way valve 24 switching the position of the valve body The sub four-way valve 1 that switches the direction locally is provided, the main four-way valve 24 drives the valve body by using electric power, and the sub four-way valve 1 is pressure generated in the main path by switching the flow direction by the main four-way valve 24. The valve body is driven using the change.

Description

  The present invention relates to a refrigeration cycle apparatus and a four-way valve.

In a conventional refrigeration cycle apparatus (air conditioner), a compressor, a first heat exchanger, a first pressure reducing device, a gas-liquid separator, a second pressure reducing device, and a second heat exchanger are sequentially connected by piping. A refrigerant circuit is configured by the main path and the gas injection path for returning the gas-phase refrigerant separated by the gas-liquid separator to the compressor. A first switching means for switching between a cooling operation in which the refrigerant discharged from the compressor flows to the first heat exchanger and a heating operation in which the refrigerant flows to the second heat exchanger; a first decompression device; A gas-liquid separator, and a second switching means provided at the entrance / exit of the decompression flow path (decompression path) provided with the second decompression device.
The flow direction switched by the first switching unit is locally switched by the second switching unit, so that the refrigerant passing through the decompression path including the gas-liquid separator can be used in both the cooling operation and the heating operation. The flow direction is constant. In addition, energy efficiency is improved by using the effect of the gas injection path.
In such an air conditioner, a four-way valve is used for the first switching means and the second switching means (see, for example, Patent Document 1).

  A conventional four-way valve has a pair of pistons at both ends, a valve body connected to the piston shaft is provided, a valve chamber in which a high pressure pipe, a low pressure pipe, and a pair of pipes are connected, and a valve A pair of cylinder chambers formed at both ends of the chamber, a pair of conduits connected to the pair of cylinder chambers, a high-pressure conduit connected to the high-pressure piping, and a low-pressure conduit connected to the low-pressure piping, , High pressure and low pressure conduits are connected to the solenoid valve. In the solenoid valve, the high-pressure pipe is selectively connected to one of the pair of pipes, and the low-pressure pipe is connected to the other pipe. The pressure of each cylinder chamber is switched by switching the solenoid valve, The flow direction is switched by selectively sliding the valve body in the axial direction (see, for example, Patent Document 2).

  In another conventional four-way valve, instead of the solenoid valve, a slow operation element having a constant temperature heating element such as a heater is provided at both ends, and the valve body is pivoted using such a slow operation element. The direction of flow is switched (for example, see Patent Document 3).

JP 2001-241797 (paragraphs [0019] to [0029], FIG. 1) Japanese Unexamined Patent Publication No. 2002-250457 (paragraph [0016], FIG. 9) Japanese Patent No. 2757997 (FIG. 1)

  In such an air conditioner, two switching means (four-way valves) are arranged in the refrigerant circuit in order to make the flow direction of the refrigerant passing through the decompression path constant in both the cooling operation and the heating operation. However, in order to selectively switch the flow direction of the refrigerant using a conventional four-way valve, a driving device using electric power such as an electromagnetic valve or a constant temperature heating element is required for each four-way valve. It becomes. For this reason, it is necessary to provide two drive units and a control unit and wiring for operating the drive units in the refrigerant circuit, and there is a problem that the air conditioner becomes large and the control becomes complicated.

The present invention has been made to solve the above-described problems, and by reducing the number of driving devices for driving the switching means, the refrigeration cycle device can be made compact and simplified. It aims at obtaining the refrigerating cycle device which can be performed.
It is another object of the present invention to provide switching means (four-way valve) that does not require a driving device.

  A refrigeration cycle apparatus according to the present invention is installed in a main path formed by connecting a compressor, a first heat exchanger, a decompression path, and a second heat exchanger by a plurality of pipes, and the main path. The refrigeration cycle apparatus includes a switching unit that connects at least three pipes of the main path, switches a flow path of the valve body to switch an internal flow path, and switches a flow direction of fluid flowing through the main path. The switching means uses at least one main switching means for driving the valve element using electric power, and a pressure change generated in the main path by switching the flow direction of the main path by the main switching means. And at least one subordinate switching means for driving the valve body.

  Further, the four-way valve according to the present invention forms a switching passage between a pair of pistons that slide in an airtight manner in the main body, a valve chamber provided between the pistons, and a valve seat surface in the valve chamber, A valve body that slides on the valve seat surface in conjunction with the piston, a pair of cylinder chambers provided on both sides of the valve chamber via the piston, a first pipe that is always in communication with the valve chamber, the valve A second pipe that opens to the seat surface and is always in communication with the switching passage, opens to the valve seat surface, and communicates with either the valve chamber or the switching passage in a mutually contradictory relationship due to the switching movement of the valve body. Four-way valve comprising a third pipe and a fourth pipe to be connected, and a pair of conduits connected to the pair of cylinder chambers, one connected to the third pipe and the other to the fourth pipe And the third pipe and the fourth pipe are connected to each other. It is intended to drive the valve body by a change in magnitude of the pressure of the fluid flowing through, respectively.

  According to the refrigeration cycle apparatus according to the present invention, since the number of drive devices for driving the switching means for switching the fluid flow direction is reduced, the refrigeration cycle apparatus can be made compact and the control can be simplified. There is an effect.

  In addition, according to the four-way valve according to the present invention, the flow path can be switched using a pressure change generated according to a change in the fluid flow direction without a driving device, so the four-way valve can be made compact. It is also possible to simplify the control of the four-way valve.

It is a section lineblock diagram of a subordinate four-way valve concerning Embodiment 1 of this invention. It is a section lineblock diagram of a subordinate four-way valve concerning Embodiment 1 of this invention. It is a refrigerant circuit figure of the air conditioner by Embodiment 1 of this invention. It is a refrigerant circuit figure of the air conditioner by Embodiment 1 of this invention. It is a refrigerant circuit figure of the air conditioner by Embodiment 1 of this invention. It is a pressure-enthalpy diagram of the air conditioner by Embodiment 1 of this invention. It is a refrigerant circuit figure of the air conditioner by Embodiment 2 of this invention. It is a pressure-enthalpy diagram of the air conditioner by Embodiment 2 of this invention. It is a refrigerant circuit figure of the air conditioner by Embodiment 3 of this invention. It is a pressure-enthalpy diagram of the air conditioner by Embodiment 3 of this invention. It is a refrigerant circuit figure of the air conditioner by Embodiment 4 of this invention. It is a pressure-enthalpy diagram of the air conditioner by Embodiment 4 of this invention. It is a refrigerant circuit figure of the air conditioner by Embodiment 5 of this invention. It is a pressure-enthalpy diagram of the air conditioner by Embodiment 5 of this invention. It is a refrigerant circuit figure of the air conditioner by Embodiment 6 of this invention. It is a pressure-enthalpy diagram of the air conditioner by Embodiment 6 of this invention. It is a refrigerant circuit figure of the air conditioner by Embodiment 7 of this invention. It is a pressure-enthalpy diagram of the air conditioner by Embodiment 7 of this invention. It is a refrigerant circuit figure of the air conditioner by Embodiment 8 of this invention. It is a pressure-enthalpy diagram of the air conditioner by Embodiment 8 of this invention. It is a refrigerant circuit figure of the air conditioner by Embodiment 9 of this invention. It is a pressure-enthalpy diagram of the air conditioner by Embodiment 9 of this invention. It is a refrigerant circuit figure of the air conditioner by Embodiment 10 of this invention. It is a refrigerant circuit figure of the air conditioner by Embodiment 11 of this invention. It is a figure which shows the flow direction of the refrigerant | coolant which passes the heat exchanger of the air conditioner by Embodiment 11 of this invention. It is a refrigerant circuit figure of the air conditioner by Embodiment 12 of this invention. It is a figure which shows the modification of the dependent four-way valve concerning Embodiment 1-12 of this invention. It is a figure which shows the modification of the dependent four-way valve concerning Embodiment 1-12 of this invention. It is a refrigerant circuit diagram of the conventional air conditioner. It is a figure which shows the flow direction of the refrigerant | coolant which passes the heat exchanger of the conventional air conditioner.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 4-way valve, 2 4-way valve main body, 3 Valve chamber, 4 1st piping, 5 2nd piping, 6 3rd piping, 7 4th piping, 8 1st piston, 9 2nd piston, 10 Piston shaft, 11 Valve body, 11a Folding flow path, 12 Switching valve, 13 First cylinder chamber, 14 Second cylinder chamber, 15 First conduit, 16 Second conduit, 17 First communication hole, 18 Second communication hole, 19 First end cover, 20 Second end cover, 21 Valve seat, 22 Pressure reducing path, 23 Compressor, 24 Main four-way valve, 25 Outdoor heat exchanger, 26 Indoor heat exchanger, 27 Pre-stage heat exchanger, 28 Post-stage heat exchanger, 29 Reheat dehumidification throttle, 30 First decompression device, 31 Second decompression device, 32 Gas-liquid separator, 33 Injection flow control valve, 34 Discharge piping, 35 Suction piping, 36 injection piping, 37 Outdoor gas piping, 38 Outdoor liquid piping, 39 Indoor gas piping, 40 Indoor liquid piping, 41 Inflow piping, 42 Outflow piping, 43 Solenoid valve, 44 Discharge side connection port, 45 Suction side connection port, 46 1st Connection port, 47 second connection port, 48 reheat dehumidification on-off valve, 49 gas-liquid separation bypass piping, 50 gas-liquid separation on-off valve, 51 gas-liquid separation check valve, 52 gas-liquid separation capillary Tube, 53 1st supercooling heat exchanger, 54 Supercooling decompression device, 55 Supercooling injection piping, 56 Supercooling on-off valve, 57 Supercooling check valve, 58 Supercooling capillary tube, 59 Nozzle , 60 diffuser, 61 ejector, 62 ejector piping, 63 ejector decompression device, 64 gas-liquid separation return flow valve, 65 second supercooling heat exchanger, 66 air Flow direction, 67 fins, 68 heat transfer tubes, 69 fin-and-tube heat exchanger, 70 supercooling bypass piping, 71 gas-liquid separation return piping, 72 expander, 73 expansion power transmission means, 74 subcompressor, 75 expansion Bypass piping, 76 expansion flow control valve, 77 first communication path, 78 second communication path.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional configuration diagram showing the subordinate switching means 1 mounted on the air conditioner according to the first embodiment. Although the subordinate switching means 1 of the present embodiment is constituted by a four-way valve, the pressure change that occurs when the flow direction of the main path is changed is not driven by the electric power of the valve body 11 that switches the flow path. The valve body 11 is driven by using it, and the flow path is switched according to the change in the flow direction of the main path.

In FIG. 1, a dependent four-way valve 1 includes a first end cover 19 and a second end cover 20 at both ends of a cylindrical switching means body (four-way valve body) 2 having an inner diameter of about 20 mm. The first pipe 4 having an inner diameter of about 9 mm is provided on the circumferential surface of 2, the second pipe 5 having an inner diameter of about 9 mm is provided on the circumferential surface opposite to the first pipe 4, and the second pipe 5 A third pipe 6 having an inner diameter of about 9 mm and a fourth pipe 7 having an inner diameter of about 9 mm are installed on both sides. Further, end portions of the second pipe 5, the third pipe 6 and the fourth pipe 7 penetrating into the four-way valve body 2 are connected to the respective pipes and the four-way valve body 2 so as to communicate with each other. A valve seat 21 having one communication hole is provided, and a valve body 11 is provided on the seat of the valve seat 21.
The valve body 11 has a concave surface portion facing the valve seat 21, and the valve body 11 slides on the seat surface of the valve seat 21 to move the third pipe 6 or the fourth pipe 7. Either one and the second pipe 5 communicate with each other. At this time, the inside of the valve body 11 serves as a folded flow path (switching passage) 11a.

Inside the four-way valve body 2, a pair of pistons (first piston 8 and second piston 9) that can slide in an airtight manner in the four-way valve body 2 are provided. The switching valve 12 is formed by connecting the two pistons 9 and the valve body 11 with a plate-like piston shaft 10 having a first communication hole 17 and a second communication hole 18. In addition, when the piston shaft 10 is rod-shaped, since there is a space between the piston shaft 10 and the four-way valve body 2, the first communication hole 17 and the second communication hole 18 may not be provided.
When the switching valve 12 slides in the axial direction inside the four-way valve body 2, the valve body 11 slides on the seat surface of the valve seat 21.

  The four-way valve body 2 includes a valve chamber 3 partitioned by the four-way valve body 2, the first piston 8, the second piston 9, the piston shaft 10, the valve body 11, and the valve seat 21, and the four-way valve body. 2, a first cylinder chamber 13 partitioned by the first end lid 19 and the first piston 8, and a second partition partitioned by the four-way valve body 2, the second end lid 20 and the second piston 9. It can be divided into a cylinder chamber 14, a folded flow path 11 a partitioned by the valve body 11 and the valve seat 21.

  Further, a first conduit 15 having an inner diameter of about 2 mm is provided so as to communicate the first end lid 19 and the third pipe 6, and the second end lid 20 and the fourth pipe 7 are communicated. Is provided with a second conduit 16 having an inner diameter of about 2 mm, the pressure in the first cylinder chamber 13 is substantially equal to the pressure in the third pipe 6, and the pressure in the second cylinder chamber 14 is the fourth pipe. 7 is almost equal to the pressure.

  Next, operation | movement of the subordinate four-way valve 1 is demonstrated using FIG. 1, FIG. FIG. 1 shows a case where the switching valve 12 moves to the first end lid 19 side, and FIG. 2 corresponds to a case where the switching valve 12 moves to the second end lid 20 side. The first pipe 4, the second pipe 5, the third pipe 6, and the fourth pipe 7 are connected to the pipes constituting the refrigerant circuit, and the refrigerant passes through the respective pipes. First, the operation of the dependent four-way valve 1 will be described.

First, the operation when the initial state of the switching valve 12 changes from the state shown in FIG. 1 to the state shown in FIG. 1 will be described.
In FIG. 1, when the pressure in the third pipe 6 and the fourth pipe 7 changes and the pressure in the third pipe 6 becomes higher than the pressure in the fourth pipe 7, the pressure in the first cylinder chamber 13 is increased. Since the pressure is higher than the pressure in the second cylinder chamber 14, the switching valve 12 moves to the second end cover 20 side and enters the state shown in FIG. 2. At this time, the first pipe 4 and the third pipe 6 communicate with each other via the valve chamber 3, and the second pipe 5 and the fourth pipe 7 communicate with each other via the folded flow path 11a. In the first cylinder chamber 13, fluid is supplied from the third pipe 6 through the first conduit 15, and in the second cylinder chamber 14, the fourth pipe 7 is connected through the second conduit 16. Fluid flows out to the
Further, since the pressure in the valve chamber 3 is substantially equal to that in the first cylinder chamber 13 and is higher than that in the second cylinder chamber 14, the second piston 9 is strongly pressed against the second end lid 20 and the valve chamber 3 does not move to the cylinder chamber 14.
Furthermore, since the pressure in the valve chamber 3 communicating with the third pipe 6 is higher than the pressure of the folded flow path 11a communicating with the fourth pipe 7, the valve body 11 is strongly pressed against the valve seat 21. The fluid in the valve chamber 3 does not move to the return channel 11a.

Next, the operation when the state changes from FIG. 2 to FIG. 1 will be described.
In FIG. 2, when the pressure in the third pipe 6 and the fourth pipe 7 changes and the pressure in the fourth pipe 7 becomes higher than the pressure in the third pipe 6, the pressure in the second cylinder chamber 14 is increased. Since the pressure is higher than the pressure in the first cylinder chamber 13, the switching valve 12 moves to the first end cover 19 side and enters the state shown in FIG. 1. At this time, the first pipe 4 and the fourth pipe 7 communicate with each other via the valve chamber 3, and the second pipe 5 and the third pipe 6 communicate with each other via the folded flow path 11a. In the second cylinder chamber 14, fluid is supplied from the fourth pipe 7 through the second conduit 16, and in the first cylinder chamber 13, the third pipe 6 is connected through the first conduit 15. Fluid flows out to the
Further, since the pressure in the valve chamber 3 is substantially equal to that in the second cylinder chamber 14 and is higher than that in the first cylinder chamber 13, the first piston 8 is strongly pressed against the first end cover 19, and the valve chamber 3 3 does not move to the cylinder chamber 13.
Furthermore, since the pressure of the valve chamber 3 communicating with the fourth pipe 7 is higher than the pressure of the folded flow path 11 a communicating with the third pipe 6, the valve body 11 is strongly pressed against the valve seat 21. The fluid in the valve chamber 3 does not move to the return channel 11a.

As described above, the subordinate four-way valve 1 according to the present embodiment guides the pressure of the third pipe 6 to the first cylinder chamber 13 via the first conduit 15 and the pressure of the fourth pipe 7. Leading to the second cylinder chamber 14 via the second conduit 16 and driving the switching valve 12 by utilizing the switching of the magnitude relationship between the pressure of the third pipe 6 and the pressure of the fourth pipe 7. Can do.
For this reason, it is necessary to provide a driving device that uses electric power such as an electromagnetic valve or a constant temperature heating element, a control unit for operating the driving device, wiring, etc., which has been conventionally required for driving the four-way valve. Therefore, it is possible to reduce the installation space related to the drive device, to realize a compact air conditioner, and to simplify control and reduce costs.
Moreover, since the dependent four-way valve 1 has a simple structure that moves the switching valve 12 using only the pressure difference between the third pipe 6 and the fourth pipe 7, it is a four-way valve for switching the refrigerant flow direction. The cost of a single unit can also be reduced.
In addition, the first pipe chamber 15 is connected to the first cylinder chamber 13 and the third pipe 6 at a distance close to the first cylinder chamber 13, and the second cylinder chamber 14 and the second cylinder chamber 14 are connected to each other. Since the fourth pipe 7 located at a short distance is connected by the second conduit 16, the first conduit 15 and the second conduit 16 can be easily routed. Furthermore, since the length of the 1st conduit | pipe 15 and the 2nd conduit | pipe 16 can be shortened, cost reduction can be achieved.

Next, the case where the above-mentioned dependent four-way valve 1 shown in FIGS. 1 and 2 is mounted on a refrigerant circuit forming an air conditioner will be described.
3, FIG. 4 and FIG. 5 are refrigerant circuit diagrams of an air conditioner equipped with the subordinate four-way valve 1 according to Embodiment 1 of the present invention. FIG. 3 shows the air conditioner performing a cooling operation. 4 corresponds to the case where the air conditioner is performing the heating operation, and FIG. 5 corresponds to the case where the air conditioner is performing the reheat dehumidifying operation.
In the refrigerant circuit of the first embodiment, the compressor 23, the first heat exchanger (outdoor heat exchanger) 25, the decompression path 22, and the second heat exchanger (indoor heat exchanger) 26 are connected by piping. And constitute the main route.
Further, on the main path, main switching means (main four-way valve) 24 for switching between a cooling operation in which the refrigerant discharged from the compressor 23 flows to the outdoor heat exchanger 25 and a heating operation in which the refrigerant flows to the indoor heat exchanger 26. , And a subordinate switching means 1 (subordinate four-way valve) provided at the entrance / exit of the decompression path 22. In the present embodiment, the decompression path 22 includes a first decompression device 30, a gas-liquid separator 32, and a second decompression device 31, and the main path includes the dependent four-way valve 1, whereby cooling operation and heating are performed. In any operation, the flow direction of the refrigerant passing through the first pressure reducing device 30, the gas-liquid separator 32, and the second pressure reducing device 31 is made constant.
In the present embodiment, a gas injection pipe 36 for returning the gas-phase refrigerant separated by the gas-liquid separator 32 to the intermediate compression process of the compressor 23 is provided.

In the first embodiment, the main four-way valve 24 is installed downstream of the compressor 23 and performs a switching operation using the electromagnetic valve 43 as in the conventional four-way valve.
The subordinate four-way valve 1 is a four-way valve shown in FIGS. 1 and 2, and drives the valve body 11 by utilizing the pressure change generated in the main path when the main four-way valve 24 changes the flow direction of the main path. However, the flow path switching operation is performed.

The main four-way valve 24 has four connection ports. The discharge side connection port 44 is connected to a discharge pipe 34 through which high-pressure refrigerant flows out of the compressor 23, and the suction side connection port 45 is connected to a suction pipe 35 that returns to the compressor 23. The first connection port 46 is connected to the outdoor gas pipe 37 connected to the outdoor heat exchanger 25, and the second connection port 47 is connected to the indoor side gas pipe 39 connected to the indoor heat exchanger 26.
The main four-way valve 24 may have any structure as long as it can switch the flow direction of the refrigerant, and the drive device for performing the switching operation is not limited to the electromagnetic valve, but has a constant temperature. It may be a heating element or the like, and the driving device may be separate from or integrated with the four-way valve body, and any switching operation may be performed by a driving device using electric power.

  In addition, the main four-way valve 24 is formed with a pair of pistons 8 and 9 to form a valve chamber 3 and a pair of cylinder chambers 13 and 14 in the same manner as the dependent four-way valve 1 shown in FIGS. The discharge pipe 34, the second pipe 5 is connected to the suction pipe 35, the third pipe 6 is connected to the outdoor gas pipe 37, and the fourth pipe 7 is connected to the indoor side gas pipe 39. Instead of connecting the conduit 15 and the second conduit 16 to the third pipe 6 and the fourth pipe 7, respectively, the conduit 15 and the second conduit 16 are connected to the solenoid valve 43. By selectively switching the pair of conduits having different pressures, the first conduit 15 and the second conduit 16, the pressure difference between the first cylinder chamber 13 and the second cylinder chamber 14 is switched, and the main four-way The switching valve 12 of the valve 24 may be driven. With this configuration, the main four-way valve 24 can be formed with a simple structure, and costs can be reduced.

  In the subordinate four-way valve 1, the inflow pipe 41, the first pressure reducing device (first throttle) 30, the gas-liquid separator 32, the second pressure reducing device (second throttle) are sequentially connected to the first pipe 4. 31 and the outflow pipe 42 are connected, and the second pipe 5 of the subordinate four-way valve 1 is connected to the outflow pipe 42. The third pipe 6 of the subordinate four-way valve 1 is connected to the indoor side liquid pipe 40 connected to the indoor heat exchanger 26, and the fourth pipe 7 is connected to the outdoor side liquid pipe 38 connected to the outdoor heat exchanger 25. Is done.

Here, the indoor heat exchanger 26 includes a front heat exchanger 27, a reheat dehumidifying throttle 29, a reheat dehumidifying on-off valve 48, and a rear heat exchanger 28 so that a reheat dehumidifying operation is possible. The
The injection pipe 36 connecting the injection port provided in the compression process of the compressor 32 and the gas-liquid separator 32 is provided with an injection flow control valve 33 for switching the presence or absence of injection. Yes.

Next, the operation of the refrigerant circuit when the air conditioner shown in Embodiment 1 performs the cooling operation, the heating operation, and the reheat dehumidification operation will be described.
First, the operation of the refrigerant circuit when the air conditioner shown in Embodiment 1 performs the cooling operation will be described with reference to FIGS. 3 and 6.
FIG. 6 is a pressure-enthalpy diagram, where the solid line indicates the operation of the refrigerant circuit related to the air conditioner shown in the first embodiment, and the alternate long and short dash line (the line connecting A-B-C-D-A). The operation | movement of the refrigerant circuit regarding the conventional air conditioner shown in FIG. A to H and K in FIG. 6 correspond to points A to H and K shown in FIGS. 3, 4, and 29. A curve W indicates a saturated liquid line and a saturated vapor line of the refrigerant. The inside of the curve W is a gas-liquid two-phase state, the left side outside the curve W is a liquid state, and the right side is a gas state.
For comparison, in the conventional air conditioner shown in FIG. 29, the compressor 100, the outdoor heat exchanger 102, the pressure reducing device 103, and the indoor heat exchanger 104 are connected by piping to form a main path. The main path is provided with only one main four-way valve 101 that switches between a cooling operation in which the refrigerant discharged from the compressor 100 flows to the outdoor heat exchanger 102 and a heating operation in which the refrigerant flows to the indoor heat exchanger 104. The main four-way valve 101 is driven by a solenoid valve (not shown). In the figure, the solid arrow indicates the refrigerant flow direction during the cooling operation, and the broken arrow indicates the refrigerant flow direction during the heating operation.

  In the conventional air conditioner, the refrigerant vapor (point A) compressed to a high pressure by the compressor 100 flows into the outdoor heat exchanger 102 via the main four-way valve 101 and is condensed in the outdoor heat exchanger. After (point B), the pressure is reduced by the pressure reducing device 103 (point C), evaporates in the indoor heat exchanger 104, and returns to the compressor 100 via the main four-way valve 101 (point D) again.

In the air conditioner shown in the first embodiment, the electromagnetic valve 43 is driven, the discharge side connection port 44 and the first connection port 46 communicate with each other, and the suction side connection port 45 and the second connection port 47 are connected. Is switched so as to communicate with each other. Further, the reheat dehumidifying on-off valve 48 of the indoor heat exchanger 26 is opened.
When the compressor 23 is driven, the fourth pipe 7 of the subordinate four-way valve 1 communicating with the discharge side of the compressor 23 becomes high pressure, while the third pipe of the subordinate four-way valve 1 communicating with the suction side of the compressor 23 is increased. The pipe 6 has a low pressure. For this reason, the switching valve 12 moves to the first end cover 19 side from the operation of the above-described subordinate four-way valve 1 to the state shown in FIG. 1, and the first pipe 4 and the fourth pipe 7 are connected to the valve chamber. 3, the second pipe 5 and the third pipe 6 communicate with each other via the folded flow path 11 a.

  The high-pressure refrigerant vapor (point E) discharged from the compressor 23 proceeds to the outdoor heat exchanger 25 via the main four-way valve 24, and is cooled by the outdoor air in the outdoor heat exchanger 25, which is a condenser, and condensed. Is done. The condensed refrigerant liquid is depressurized by the first pressure reducing device 30 after passing through the subordinate four-way valve 1 (point B), and becomes a gas-liquid two-phase state in which refrigerant vapor and refrigerant liquid of intermediate pressure are mixed. (Point F) flows into the gas-liquid separator 32. In the gas-liquid separator 32, the refrigerant vapor (K point) and the refrigerant liquid (G point) are separated, and the separated intermediate pressure refrigerant liquid is further depressurized by the second decompression device 31 (H point), and again. After passing through the subordinate four-way valve 1, it flows into the indoor heat exchanger 26, which is an evaporator. The refrigerant proceeds in sequence to the front-stage heat exchanger 27, the reheat dehumidification on-off valve 48, and the rear-stage heat exchanger 28, and heats from indoor air in the front-stage heat exchanger 27 and the rear-stage heat exchanger 28 that are evaporators. Take away and evaporate. The evaporated refrigerant vapor flows into the compressor 23 after passing through the main four-way valve 24 (D point).

  On the other hand, the flow rate of the intermediate-pressure refrigerant vapor (point K) separated by the gas-liquid separator 32 is adjusted by the injection flow control valve 33 and passes through the injection pipe 36 in the middle of the compression process of the compressor 23 ( The refrigerant at point K) is mixed with the refrigerant at point K and the refrigerant at point I (point J). Further, the refrigerant is compressed to point E and discharged again.

When the air conditioner shown in Embodiment 1 is air-cooled, the air-liquid separator 32 is provided. Therefore, the enthalpy difference (h3-h1) of the indoor heat exchanger 26 that is an evaporator is the enthalpy of the conventional air conditioner. It becomes larger than the difference (h3−h2). Therefore, the evaporation capacity, that is, the cooling capacity is increased as compared with the conventional example.
Further, the flow rate of refrigerant flowing through the compressor 23 includes the injection pipe 36, and thus increases due to the flow rate of refrigerant injected from the injection pipe 36 into the compressor 23. Therefore, although the input of the compressor 23 also increases, since the evaporation capacity is larger than that, the coefficient of performance during the cooling operation obtained by dividing the evaporation capacity by the input of the compressor 23 is increased as compared with the conventional example. Further, since the temperature (point E) when discharged from the compressor 23 is lower than that of the conventional example (point A), the reliability of the compressor 23 is improved.

Next, the operation of the refrigerant circuit when the air conditioner of Embodiment 1 performs the heating operation will be described using FIG. The shape of the pressure-enthalpy diagram when the air conditioner is performing the heating operation is almost the same as that when the cooling operation described with reference to FIG. 6 is performed. However, when the conventional air conditioner shown in FIG. 29 performs the heating operation, the point B and the point C are interchanged.
In FIG. 4, the main four-way valve is driven such that the solenoid valve 43 is driven so that the discharge side connection port 44 and the second connection port 47 communicate with each other and the suction side connection port 45 and the first connection port 46 communicate with each other. 24 is switched. Further, the reheat dehumidifying on-off valve 48 of the indoor heat exchanger 26 is opened.
When the compressor 23 is driven, the third pipe 6 of the subordinate four-way valve 1 that communicates with the discharge side of the compressor 23 becomes high pressure, while the fourth pipe of the subordinate four-way valve 1 that communicates with the suction side of the compressor 23. The piping 7 becomes a low pressure. Therefore, the switching valve 12 moves to the second end cover 20 side from the operation of the subordinate four-way valve 1 described above, and the state shown in FIG. 2 is established. The second pipe 5 and the fourth pipe 7 communicate with each other via the folded flow path 11a.

  The high-pressure refrigerant vapor (point E) discharged from the compressor 23 flows into the indoor heat exchanger 26 via the main four-way valve 24. The refrigerant proceeds in sequence to the rear heat exchanger 28, the reheat dehumidifying on-off valve 48, and the front heat exchanger 27, and is cooled by indoor air in the front heat exchanger 27 and the rear heat exchanger 28 that are condensers. Condensed. The condensed refrigerant liquid is reduced in pressure by the first pressure reducing device 30 after passing through the dependent four-way valve 1 (point B), and becomes a gas-liquid two-phase state in which refrigerant vapor and refrigerant liquid of intermediate pressure are mixed. (Point F) flows into the gas-liquid separator 32. In the gas-liquid separator 32, the refrigerant vapor (K point) and the refrigerant liquid (G point) are separated, and the separated intermediate pressure refrigerant liquid is further depressurized by the second decompression device 31 (H point), and again. After passing through the dependent four-way valve 1, the process proceeds to the outdoor heat exchanger 25, where the outdoor heat exchanger 25, which is an evaporator, takes heat from the outside air and evaporates. The evaporated refrigerant vapor flows into the compressor 23 after passing through the main four-way valve 24 (point D).

  On the other hand, similarly to the cooling operation, the flow rate of the intermediate-pressure refrigerant vapor (point K) separated by the gas-liquid separator 32 is adjusted by the injection flow control valve 33, passes through the injection pipe 36, and passes through the compressor 23. In the middle of the compression process (point I), the refrigerant at point K and the refrigerant at point I are mixed (point J). Further, the refrigerant is compressed to point E and discharged again.

When the air conditioner shown in Embodiment 1 is operated for heating, since it has the gas-liquid separator 32 and the injection pipe 36, the refrigerant flow rate flowing through the indoor heat exchanger 26 that is a condenser is reduced from the injection pipe 36 to the compressor. It increases with the flow rate of the refrigerant injected into 23. For this reason, the condensing capacity, that is, the heating capacity is increased as compared with the conventional example.
Further, the flow rate of the refrigerant flowing through the compressor 23 increases due to the flow rate of the refrigerant injected into the compressor 23 from the injection pipe 36. Therefore, although the input of the compressor 23 also increases, since the condensing capacity is larger than that, the coefficient of performance during the heating operation obtained by dividing the condensing capacity by the input of the compressor 23 is increased as compared with the conventional example.
Further, since the temperature (point E) when discharged from the compressor is lower than the conventional example (point A), the reliability of the compressor is improved.

Next, the operation of the refrigerant circuit when the air conditioner shown in Embodiment 1 performs the reheat dehumidifying operation will be described with reference to FIG.
The electromagnetic valve 43 is driven to switch the main four-way valve 24 so that the discharge side connection port 44 and the first connection port 46 communicate with each other and the suction side connection port 45 and the second connection port 47 communicate with each other. Further, the reheat dehumidifying on-off valve 48 is opened, the injection flow control valve 33 is closed, and at least one of the first pressure reducing device 30 and the second pressure reducing device 31 is not fully opened but is throttled.
When the compressor 23 is driven, the fourth pipe 7 of the subordinate four-way valve 1 communicating with the discharge side of the compressor 23 becomes high pressure, while the third pipe of the subordinate four-way valve 1 communicating with the suction side of the compressor 23 is increased. The pipe 6 has a low pressure. Therefore, the switching valve 12 moves to the first end cover 19 side from the operation of the dependent four-way valve 1 described above, and the state shown in FIG. 1 is established, and the first pipe 4 and the fourth pipe 7 are connected to the valve chamber 3. The second pipe 5 and the third pipe 6 communicate with each other via the return channel 11a. Thereafter, the reheat dehumidifying on-off valve 48 is closed, and the first decompressor 30 and the second decompressor 31 are fully opened.

  The high-pressure refrigerant vapor discharged from the compressor 23 proceeds to the outdoor heat exchanger 25 via the main four-way valve 24, and is cooled and condensed by the outdoor air in the outdoor heat exchanger 25 that is a condenser. At this time, the refrigerant vapor is not completely liquefied by the outdoor heat exchanger 25 and remains in the gas-liquid two-phase state in which the refrigerant vapor and the refrigerant liquid coexist, and the first pressure reducing device via the dependent four-way valve 1. 30, passes through the gas-liquid separator 32 and the second pressure reducing device 31, and again flows into the heat exchanger 26 through the dependent four-way valve 1. The refrigerant that has flowed into the indoor heat exchanger 26 is cooled and condensed by indoor air in a pre-stage heat exchanger 27 that is a condenser, and is then depressurized by a reheat dehumidifying restrictor 29, and is then heated by a post-stage heat that is an evaporator. The exchanger 28 evaporates by taking heat from indoor air. The evaporated refrigerant vapor flows into the compressor 23 via the main four-way valve 24. The indoor air is dehumidified and cooled in the post-stage heat exchanger 28 serving as an evaporator and heated in the pre-stage heat exchanger 27 serving as a condenser, and thus passes through the pre-stage heat exchanger 27 and the post-stage heat exchanger 28. By mixing the indoor air, the indoor air can be air-conditioned while dehumidifying.

  In the reheat dehumidifying operation, as described above, in the first stage, the main four-way valve 24 is brought into the same state as in the cooling operation, and the reheat dehumidifying on-off valve 48 is opened and the injection flow control valve 33 is set. Is closed, and at least one of the first pressure reducing device 30 or the second pressure reducing device 31 is not fully opened but is throttled. Thereafter, in the second stage, the reheat dehumidifying on-off valve 48 is closed, and the first decompressor 30 and the second decompressor 31 are fully opened. The valves and the pressure reducing devices are opened and closed by a control device (not shown).

  In this way, the reheat dehumidifying operation can be performed after the switching valve 12 of the dependent four-way valve 1 is reliably switched to the state shown in FIG. 1, and the first decompressor 30, the gas-liquid separator 32, and The flow direction of the refrigerant passing through the second decompression device 31 can always be a constant direction. Moreover, when it has directionality with respect to the refrigerant | coolant which passes through the pressure reduction path 22, while being able to satisfy the pressure reduction amount and flow control amount which the pressure reduction path 22 has, the structural lifetime of the pressure reduction path 22 can be extended.

  As described above, the subordinate four-way valve 1 used in the air conditioner of Embodiment 1 has the configuration shown in FIGS. 1 and 2, so that the subordinate four-way valve 1 is used for cooling operation, heating operation, and reheating. When the dehumidifying operation is performed, the switching valve of the dependent four-way valve 1 is automatically received in response to the pressure difference between the third pipe 6 and the fourth pipe 7 without using an electromagnetic valve that controls only the dependent four-way valve 1. 12 can be switched. As a result, it is possible to reduce the number of solenoid valves used in the air conditioner, the control unit for operating the solenoid valves, and the wiring, so that the air conditioner can be made compact, and the control is simplified and the cost is reduced. Can be realized.

  In addition, the air conditioner shown in the first embodiment includes the gas-liquid separator 32 in the decompression path 22 and the dependent four-way valve 1 connected to both ends of the decompression path 22, so that the cooling operation or the heating operation is performed. In either case, the flow direction of the refrigerant passing through the gas-liquid separator 32 can be made constant by switching the switching valve 12 of the dependent four-way valve 1. Therefore, the refrigerant flows into the gas-liquid separator 32 from the inflow pipe 41 and is separated into the refrigerant liquid and the refrigerant vapor, and the separated refrigerant liquid flows out from the gas-liquid separator 32 through the outflow pipe 42. Thus, it is possible to always form a refrigerant flow in which the gas-liquid separator 32 functions such that the separated refrigerant vapor flows out of the gas-liquid separator 32 through the injection pipe 36. Therefore, the capacity and the coefficient of performance can be increased both in the cooling operation and the heating operation of the air conditioner. Further, the reliability of the compressor 23 is also improved.

  In all of the cooling operation, the heating operation, and the reheat dehumidifying operation, the pressure in the valve chamber 3 of the subordinate four-way valve 1 becomes higher than the pressure in the return flow path 11a. Strongly pressed. Therefore, the refrigerant does not short-circuit from the fourth pipe 7 to the second pipe 5 in the dependent four-way valve 1, and a refrigerant circuit for performing a desired operation can be formed.

  In the first embodiment, since no injection is performed in the reheat dehumidifying operation, there is no need to perform gas-liquid separation. Therefore, the refrigerant may flow in either direction through the gas-liquid separator 32, and before the start of the compressor 23, the reheat dehumidification on-off valve 48 is closed, and the first decompressor 30 and the second decompressor. The device 31 may be left fully open.

  Further, the pressure difference between the third pipe 6 and the fourth pipe 7 in the reheat dehumidifying operation is smaller than that in the case where the air conditioner performs the cooling operation or the heating operation. Even if the force pressed against the valve seat 21 is reduced and the refrigerant shortcuts from the fourth pipe 7 to the third pipe 6 in the dependent four-way valve 1, there is no problem in the reheat dehumidifying operation.

  Further, in the first embodiment, in order to perform the reheat dehumidification operation, the indoor heat exchanger 26 is replaced with the first indoor heat exchanger 27, the rear heat exchanger 28, the reheat dehumidifying throttle 29, the reheat dehumidification. However, if the air conditioner does not perform the reheat dehumidifying operation, only the indoor heat exchanger 28 may be used as the indoor heat exchanger 26. Further, in order to perform the reheat dehumidification operation, the reheat dehumidification throttle 29 and the reheat dehumidification on-off valve 48 are used in combination. It doesn't matter.

  Moreover, in order to control the refrigerant | coolant flow volume utilized for injection, although the flow control valve 33 for injection was used, it may be an on-off valve which only switches the presence or absence of injection.

The throttle amount of the first decompressor 30 and the throttle amount of the second decompressor 31 are arbitrary, and each of the cooling operation and the heating operation of the air conditioner can be performed by using a decompressor having a variable valve opening. In operation, the optimum operation that maximizes the coefficient of performance is possible.
The structure of the compressor 23 is arbitrary, and a refrigerant may be injected between the front stage and the rear stage as a two-stage compressor of the front stage and the rear stage.

Embodiment 2. FIG.
FIG. 7 is a refrigerant circuit diagram of an air conditioner according to Embodiment 2 of the present invention. The air conditioner of the second embodiment is different from the first embodiment in that the decompression path 22 does not include the second decompression device 31, but includes the first decompression device 30 and the gas-liquid separator 32. ing. Further, the main path includes the subordinate four-way valve 1 so that the flow direction of the refrigerant passing through the decompression path 22 is constant in both the cooling operation and the heating operation.
In the second embodiment, the injection flow control valve 33 and the injection pipe 36 are not provided. Instead, the gas-liquid returning the gas-phase fluid separated by the gas-liquid separator 32 to the compressor 23. A separation bypass pipe 49 is provided. The gas-liquid separation bypass pipe 49 is connected to the suction pipe 35 of the compressor 23, and is provided with a gas-liquid separation on-off valve 50, a gas-liquid separation check valve 51, and a gas-liquid separation capillary tube 52. .
Moreover, in the figure, the solid line arrows indicate the flow direction of the refrigerant during the cooling operation, and the broken line arrows indicate the flow direction of the refrigerant during the heating operation. In the figure, each of the four-way valves 1 and 24 shows a state during cooling operation.
Further, in order to omit the description of the reheat dehumidifying operation, the configuration of the indoor heat exchanger 26 includes a front heat exchanger 27, a reheat dehumidifying throttle 29, a reheat dehumidifying on-off valve 48, and a rear heat exchanger. 28, not shown, and an indoor heat exchanger 26.

Hereinafter, the operation of the refrigerant circuit when the air-conditioning apparatus shown in Embodiment 2 performs the cooling operation and the heating operation will be described with reference to FIGS. 7 and 8.
FIG. 8 is a pressure-enthalpy diagram, where the solid line indicates the operation of the refrigerant circuit of the air conditioner shown in the second embodiment, and the alternate long and short dash line (the line connecting A-B-C-D-A). The operation | movement of the refrigerant circuit of the conventional air conditioner shown in FIG. A to G in the figure correspond to points A to G shown in FIGS. 7 and 29.

First, a case where the air conditioner performs a cooling operation will be described.
In the conventional air conditioner, the refrigerant vapor (point A) compressed to a high pressure by the compressor 100 flows into the outdoor heat exchanger 102 via the main four-way valve 101 and is condensed in the outdoor heat exchanger. After (point B), the pressure is reduced by the pressure reducing device 103 (point C), evaporates in the indoor heat exchanger 104, and returns to the compressor 100 via the main four-way valve 101 (point D) again. At this time, since the refrigerant vapor that does not contribute to evaporation also flows into the indoor heat exchanger 104 together with the refrigerant liquid, pressure loss (P1-P3) occurs before and after the refrigerant passes through the indoor heat exchanger 104.
When FIG. 8 is compared with FIG. 6 shown in the first embodiment, the slope of the straight line from the point C to the point D is different in the operation of the conventional example. Strictly speaking, the straight line from the point C to the point D in FIG. 6 has the same inclination as that in FIG. 8 due to pressure loss, but FIG. 6 shows this inclination ignored, and FIG. 8 emphasizes the inclination. Show.

On the other hand, in the air conditioner shown in the second embodiment, the electromagnetic valve 43 is driven, the discharge side connection port 44 and the first connection port 46 communicate with each other, and the suction side connection port 45 and the second connection port 47 are connected. The main four-way valve 24 is switched so as to communicate with each other. Further, the gas-liquid separation on-off valve 50 is opened.
When the compressor 23 is driven, the fourth pipe 7 of the subordinate four-way valve 1 communicating with the discharge side of the compressor 23 becomes high pressure, while the third pipe of the subordinate four-way valve 1 communicating with the suction side of the compressor 23 is increased. The pipe 6 has a low pressure. Therefore, the switching valve 12 moves to the first end cover 19 side from the operation of the dependent four-way valve 1 described above, and the state shown in FIG. 1 is established, and the first pipe 4 and the fourth pipe 7 are connected to the valve chamber 3. The second pipe 5 and the third pipe 6 communicate with each other via the return channel 11a.

The high-pressure refrigerant vapor (point A) discharged from the compressor 23 proceeds to the outdoor heat exchanger 25 via the main four-way valve 24, and is cooled by the outdoor air in the outdoor heat exchanger 25, which is a condenser, and condensed. Is done. The condensed refrigerant liquid is reduced in pressure by the first pressure reducing device 30 after passing through the subordinate four-way valve 1 (point B), and becomes a gas-liquid two-phase state in which low-pressure refrigerant vapor and refrigerant liquid are mixed ( C), and flows into the gas-liquid separator 32. In the gas-liquid separator 32, the refrigerant vapor (point F) and the refrigerant liquid (point E) are separated, and the separated refrigerant liquid proceeds to the indoor heat exchanger 26 via the dependent four-way valve 1 and is an evaporator. The indoor heat exchanger 26 evaporates by taking heat from indoor air. At this time, the refrigerant vapor that does not contribute to evaporation does not flow into the indoor heat exchanger 26 together with the refrigerant liquid. Therefore, the pressure loss (P1-P2) before and after the refrigerant passes through the indoor heat exchanger 26 is smaller than the pressure loss (P1-P3) of the conventional example. The evaporated refrigerant vapor passes through the main four-way valve 24 (point G) and then proceeds to the compressor 23.
On the other hand, the refrigerant vapor (point F) separated by the gas-liquid separator 32 proceeds to the gas-liquid separation capillary tube 52 via the gas-liquid separation on-off valve 50 and the gas-liquid separation check valve 51, and the gas-liquid is separated. After the pressure is reduced in the separation capillary tube 52, the refrigerant vapor that has passed through the main four-way valve 24 is merged (point G) and flows into the compressor 23. The refrigerant vapor that has flowed into the compressor 23 is compressed to point A and discharged again.

When the air conditioner shown in the second embodiment is air-cooled, the air-liquid separator 32 is provided. Therefore, the enthalpy difference (h3-h1) of the indoor heat exchanger 26 that is an evaporator is the enthalpy of the conventional air conditioner. It becomes larger than the difference (h3−h2). Therefore, the evaporation capacity, that is, the cooling capacity is increased as compared with the conventional example.
Further, since only the refrigerant liquid from the gas-liquid separator 32 flows into the indoor heat exchanger 26, the pressure loss of the indoor heat exchanger 26 that is an evaporator is reduced, and the suction pressure of the compressor 23 is increased. Therefore, when the air conditioner is operated so that the evaporation capacity is constant, the input of the compressor 23 decreases, and the coefficient of performance during cooling operation obtained by dividing the evaporation capacity by the input of the compressor 23 is conventionally More than the example.

Next, the heating operation will be described. The shape of the pressure-enthalpy diagram when the heating operation is performed is substantially the same as FIG. However, when heating the conventional air conditioner shown in FIG. 29, the points B and C are interchanged.
The solenoid valve 43 is driven to switch the main four-way valve 24 so that the discharge side connection port 44 and the second connection port 47 communicate with each other and the suction side connection port 45 and the first connection port 46 communicate with each other. Further, the gas-liquid separation on-off valve 50 is opened.
When the compressor 23 is driven, the third pipe 6 of the subordinate four-way valve 1 that communicates with the discharge side of the compressor 23 becomes high pressure, while the fourth pipe of the subordinate four-way valve 1 that communicates with the suction side of the compressor 23. The piping 7 becomes a low pressure. Therefore, the switching valve 12 moves to the second end cover 20 side from the operation of the subordinate four-way valve 1 described above, and the state shown in FIG. 2 is established. The second pipe 5 and the fourth pipe 7 communicate with each other via the folded flow path 11a.

The high-pressure refrigerant vapor (point A) discharged from the compressor 23 proceeds to the indoor heat exchanger 26 via the main four-way valve 24, and is cooled by indoor air in the indoor heat exchanger 26 that is a condenser. , Condensed. The condensed refrigerant liquid is reduced in pressure by the first pressure reducing device 30 after passing through the subordinate four-way valve 1 (point B), and becomes a gas-liquid two-phase state in which low-pressure refrigerant vapor and refrigerant liquid are mixed ( C), and flows into the gas-liquid separator 32. In the gas-liquid separator 32, the refrigerant vapor (point F) and the refrigerant liquid (point E) are separated, and the separated refrigerant liquid passes through the dependent four-way valve 1 and then proceeds to the outdoor heat exchanger 25, where the evaporator In the outdoor heat exchanger 25, the heat is taken from the outside air to evaporate. The evaporated refrigerant vapor passes through the main four-way valve 24 (point G) and then proceeds to the compressor 23.
On the other hand, the refrigerant vapor (point F) separated by the gas-liquid separator 32 proceeds to the gas-liquid separation capillary tube 52 via the gas-liquid separation on-off valve 50 and the gas-liquid separation check valve 51, and the gas-liquid is separated. After the pressure is reduced in the separation capillary tube 52, the refrigerant vapor that has passed through the main four-way valve 24 is merged (point G) and flows into the compressor 23. The refrigerant vapor that has flowed into the compressor 23 is compressed to point A and discharged again.

When the air conditioner shown in Embodiment 2 is heated, only the refrigerant liquid from the gas-liquid separator 32 flows into the outdoor heat exchanger 25, so that the pressure loss of the outdoor heat exchanger 25 is reduced (P1). -P2). Therefore, the intake temperature of the compressor rises and the refrigerant circulation flow rate of the air conditioner increases, so that the condensing capacity, that is, the heating capacity is increased as compared with the conventional example.
Further, when the air conditioner is operated so that the condensing capacity becomes constant due to the increase of the suction pressure of the compressor (P2-P3), the input of the compressor is reduced, and the condensing capacity is input to the compressor 23. The coefficient of performance at the time of heating operation obtained by dividing by is increased from the conventional example.

  As described above, since the subordinate four-way valve 1 used in the air conditioner of the second embodiment has the configuration shown in FIGS. 1 and 2, the subordinate four-way valve 1 is used for cooling as in the first embodiment. When the operation and the heating operation are performed, the switching of the dependent four-way valve 1 is automatically performed in response to the pressure difference between the third pipe 6 and the fourth pipe 7 without using an electromagnetic valve that controls only the dependent four-way valve 1. The valve 12 can be switched. As a result, it is possible to reduce the number of solenoid valves used in the air conditioner, the control unit for operating the solenoid valves, and the wiring, so that the air conditioner can be made compact, and the control is simplified and the cost is reduced. Can be realized.

  In addition, the air conditioner shown in the second embodiment includes the gas-liquid separator 32 in the decompression path 22 and the dependent four-way valve 1 connected to both ends of the decompression path 22, so that the cooling operation or the heating operation is performed. In either case, the flow direction of the gas-liquid separator 32 can be made constant by switching the switching valve 12 of the dependent four-way valve 1. Therefore, the refrigerant flows into the gas-liquid separator 32 from the inflow pipe 41 and is separated into the refrigerant liquid and the refrigerant vapor, and the separated refrigerant liquid passes from the gas-liquid separator 32 through the outflow pipe 42 to the outdoor heat exchanger. It is possible to always form a refrigerant flow in which the gas-liquid separator 32 functions such that the refrigerant vapor flows out to the refrigerant 26 and flows out to the compressor 23 through the gas-liquid separation pipe 49. Therefore, the capacity and the coefficient of performance can be increased both in the cooling operation and the heating operation of the air conditioner.

  Further, in either the cooling operation or the heating operation, the pressure in the valve chamber 3 of the subordinate four-way valve 1 becomes higher than the pressure in the return flow path 11a, and the valve body 11 is strongly pressed against the valve seat 21. Therefore, the refrigerant does not short-circuit from the fourth pipe 7 to the second pipe 5 in the dependent four-way valve 1, and a refrigerant circuit for performing a desired operation can be formed.

Although the description of the reheat dehumidifying operation is omitted in the present embodiment, the reheat dehumidifying operation can be performed by making the configuration of the indoor heat exchanger 26 the same as in the first embodiment.
Further, instead of the gas-liquid separation on-off valve 50, the gas-liquid separation check valve 51, and the gas-liquid separation capillary tube 52, a gas-liquid separation flow control valve is provided to pass through the gas-liquid separation bypass pipe 49. The refrigerant vapor flow rate may be adjusted.

Embodiment 3 FIG.
FIG. 9 is a refrigerant circuit diagram of an air conditioner according to Embodiment 3 of the present invention. In the air conditioner of the third embodiment, unlike the first embodiment, the decompression path 22 does not include the second decompression device 31 and the gas-liquid separator 32, and the first decompression device 30 and the first decompression device 1 supercooling heat exchanger 53 (provided on the upstream side of the first decompression device 30). Further, the main path includes the subordinate four-way valve 1 so that the flow direction of the refrigerant passing through the decompression path 22 is constant in both the cooling operation and the heating operation.
In the third embodiment, the injection flow control valve 33 and the injection pipe 36 are not provided, but a supercooling injection pipe 55 is provided instead. The supercooling injection pipe 55 is branched from between the subordinate four-way valve 1 and the first supercooling heat exchanger 53 (point B), and the supercooling decompression device 54 that makes the branched refrigerant intermediate pressure, and 1 is connected to an injection port provided in the middle of the compression process of the compressor 32 via a supercooling heat exchanger 53. In the first supercooling heat exchanger 53, the intermediate-pressure refrigerant after passing through the supercooling decompression device 54 and the high-pressure refrigerant passing through the subordinate four-way valve 1 exchange heat.
Moreover, in the figure, the solid line arrows indicate the flow direction of the refrigerant during the cooling operation, and the broken line arrows indicate the flow direction of the refrigerant during the heating operation. In the figure, each of the four-way valves 1 and 24 shows a state during cooling operation.

Hereinafter, the operation of the refrigerant circuit when the air conditioner shown in Embodiment 3 performs the cooling operation and the heating operation will be described with reference to FIGS. 9 and 10.
FIG. 10 is a pressure-enthalpy diagram, where the solid line indicates the operation of the refrigerant circuit of the air conditioner shown in the third embodiment, and the alternate long and short dash line (the line connecting A-B-C-D-A). The operation | movement of the refrigerant circuit of the conventional air conditioner shown in FIG. A to H and K in the figure correspond to points A to H and K shown in FIG. 9 and FIG.

First, a case where the air conditioner performs a cooling operation will be described.
The operation of the conventional air conditioner is the same as that of the conventional operation shown in FIG. 6, and also in FIG. 10, the inclination of the straight line from the point C to the point D is ignored.
On the other hand, in the air conditioner shown in the third embodiment, the solenoid valve 43 is driven, the discharge side connection port 44 and the first connection port 46 communicate, and the suction side connection port 45 and the second connection port 47. The main four-way valve 24 is switched so as to communicate with each other.
When the compressor 23 is driven, the fourth pipe 7 of the subordinate four-way valve 1 communicating with the discharge side of the compressor 23 becomes high pressure, while the third pipe of the subordinate four-way valve 1 communicating with the suction side of the compressor 23 is increased. The pipe 6 has a low pressure. Therefore, the switching valve 12 moves to the first end cover 19 side from the operation of the dependent four-way valve 1 described above, and the state shown in FIG. 1 is established, and the first pipe 4 and the fourth pipe 7 are connected to the valve chamber 3. The second pipe 5 and the third pipe 6 communicate with each other via the return channel 11a.

The high-pressure refrigerant vapor (point E) discharged from the compressor 23 proceeds to the outdoor heat exchanger 25 through the main four-way valve 24, and is cooled by the outdoor air in the outdoor heat exchanger 25, which is a condenser, and condensed. Is done. The condensed refrigerant liquid passes through the dependent four-way valve 1 (point B), and is further cooled by an intermediate-pressure refrigerant that flows oppositely in the first subcooling heat exchanger 53 (point F). After the pressure is reduced by the pressure reducing device 30 (point H), the process proceeds to the indoor heat exchanger 26 via the dependent four-way valve 1, and the indoor heat exchanger 26, which is an evaporator, takes heat from the indoor air and evaporates. The evaporated refrigerant vapor passes through the main four-way valve 24 (D point) and then proceeds to the compressor 23.
On the other hand, a part of the refrigerant liquid branched to the supercooling injection pipe 55 at point B is decompressed to an intermediate pressure by the supercooling decompression device 54 (point G), and then the first supercooling heat exchanger 53. The heat is taken away from the high-pressure refrigerant that flows in the opposite direction to evaporate (point K), and injected in the middle of the compression process of the compressor 23 (point I), and the refrigerant at point K and the refrigerant at point I are mixed ( J point). Further, the refrigerant is compressed to point E and discharged again.

When the air conditioner shown in Embodiment 3 is air-cooled, the first supercooling heat exchanger 53 is provided, so that the enthalpy difference (h3-h1) of the indoor heat exchanger 26 that is an evaporator is the conventional air. It becomes larger than the enthalpy difference (h3-h2) of the harmony machine. Therefore, the evaporation capacity, that is, the cooling capacity is increased as compared with the conventional example.
Further, since the supercooling injection pipe 55 is provided, the flow rate of the refrigerant flowing through the compressor 23 is increased by the flow rate of the refrigerant injected from the supercooling injection pipe 55 into the compressor 23. Therefore, although the input of the compressor 23 also increases, since the evaporation capacity is larger than that, the coefficient of performance during the cooling operation obtained by dividing the evaporation capacity by the input of the compressor 23 is increased as compared with the conventional example. Further, since the temperature when discharged from the compressor is lower than that of the conventional example, the reliability of the compressor is improved.

Next, the heating operation will be described. The shape of the pressure-enthalpy diagram when the heating operation is performed is almost the same as that in FIG. However, when heating the conventional air conditioner shown in FIG. 29, the points B and C are interchanged.
The solenoid valve 43 is driven to switch the main four-way valve 24 so that the discharge side connection port 44 and the second connection port 47 communicate with each other and the suction side connection port 45 and the first connection port 46 communicate with each other.
When the compressor 23 is driven, the third pipe 6 of the subordinate four-way valve 1 that communicates with the discharge side of the compressor 23 becomes high pressure, while the fourth pipe of the subordinate four-way valve 1 that communicates with the suction side of the compressor 23. The piping 7 becomes a low pressure. Therefore, the switching valve 12 moves to the second end cover 20 side from the operation of the subordinate four-way valve 1 described above, and the state shown in FIG. 2 is established. The second pipe 5 and the fourth pipe 7 communicate with each other via the folded flow path 11a.

The high-pressure refrigerant vapor (point E) discharged from the compressor 23 proceeds to the indoor heat exchanger 26 via the main four-way valve 24 and is cooled by indoor air in the indoor heat exchanger 26 that is a condenser. , Condensed. After the condensed refrigerant liquid passes through the dependent four-way valve 1 (point B), it is further cooled by the intermediate pressure refrigerant flowing oppositely in the first subcooling heat exchanger 53 (point F), and the first After the pressure is reduced by the pressure reducing device 30 (point H), the process proceeds to the outdoor heat exchanger 25 via the dependent four-way valve 1, and the outdoor heat exchanger 25, which is an evaporator, takes heat from the outside air and evaporates. The evaporated refrigerant vapor passes through the main four-way valve 24 (D point) and then proceeds to the compressor 23.
On the other hand, a part of the refrigerant liquid branched to the supercooling injection pipe 55 at point B is decompressed to an intermediate pressure by the supercooling decompression device 54 (point G), and then the first supercooling heat exchanger 53. The heat is taken away from the high-pressure refrigerant that flows in the opposite direction to evaporate (point K), and injected in the middle of the compression process of the compressor 23 (point I), and the refrigerant at point K and the refrigerant at point I are mixed ( J point). Furthermore, the refrigerant is compressed to point E and discharged again.

When the air conditioner shown in the third embodiment is heated, the supercooling injection pipe 55 is provided. Therefore, the refrigerant flow rate flowing through the indoor heat exchanger 26 that is a condenser is changed from the supercooling injection pipe 55 to the compressor 23. It increases with the flow rate of the refrigerant injected into the tank. For this reason, the condensing capacity, that is, the heating capacity is increased as compared with the conventional example.
Further, the flow rate of the refrigerant flowing through the compressor 23 increases due to the flow rate of the refrigerant injected into the compressor 23 from the subcooling injection pipe 55. Therefore, although the input of the compressor 23 also increases, since the condensing capacity is larger than that, the coefficient of performance during the heating operation obtained by dividing the condensing capacity by the input of the compressor 23 is increased as compared with the conventional example. Moreover, since the temperature when discharged from the compressor 23 is lower than that of the conventional example, the reliability of the compressor 23 is improved.

  As described above, the subordinate four-way valve 1 used in the air conditioner of the third embodiment has the configuration shown in FIGS. 1 and 2, and thus the subordinate four-way valve 1 was used for cooling operation and heating operation. In this case, the switching valve 12 of the dependent four-way valve 1 can be automatically switched in response to a pressure difference between the third pipe 6 and the fourth pipe 7 without using an electromagnetic valve that controls only the dependent four-way valve 1. it can. As a result, it is possible to reduce the number of solenoid valves used in the air conditioner, the control unit for operating the solenoid valves, and the wiring, so that the air conditioner can be made compact, and the control is simplified and the cost is reduced. Can be realized.

  In the air conditioner shown in the third embodiment, the decompression path 22 includes the first decompression device 30 and the first supercooling heat exchanger 53, and the subordinate four-way valve is disposed at both ends of the decompression path 22. 1 and a path for flowing the high-pressure refrigerant to the first decompression device 30 before the high-pressure refrigerant flows into the first decompression device 30 in both the cooling operation and the heating operation, and a supercooling decompression device The pressure is reduced to an intermediate pressure by 54 and branched to an injection path for returning to the intermediate compression process of the compressor 23. Further, the first supercooling heat exchanger 53 is provided so that the refrigerant after passing through the supercooling decompression device 54 and the refrigerant flowing into the first decompression device 30 exchange heat. Therefore, the capacity and the coefficient of performance can be increased in both the cooling operation and the heating operation of the air conditioner. Further, the reliability of the compressor is improved.

  Further, in both the cooling operation and the heating operation, the high-pressure refrigerant and the intermediate-pressure refrigerant branched in front of the first subcooling heat exchanger 53 flow oppositely in the first subcooling heat exchanger 53. Since it did in this way, the heat exchange performance of the 1st subcooling heat exchanger 53 can be improved.

  Further, in both the cooling operation and the heating operation, the pressure in the valve chamber 3 of the subordinate four-way valve 1 becomes higher than the pressure in the return flow path 11a, and the valve body 11 is strongly pressed against the valve seat 21. However, there is no shortcut from the fourth pipe 7 to the second pipe 5 in the dependent four-way valve 1, and a refrigerant circuit for performing a desired operation can be formed.

In addition, the structure of the 1st subcooling heat exchanger 53 is arbitrary, and the refrigerant | coolant which has a different pressure should just be heat-exchangeable.
Further, in the present embodiment, the flow of the high-pressure refrigerant and the intermediate-pressure refrigerant that passes through the first subcooling heat exchanger 53 is opposed, but it may be parallel flow.
In the present embodiment, the description of the reheat dehumidification operation is omitted, but the reheat dehumidification operation can be performed by making the configuration of the indoor heat exchanger 26 the same as in the first embodiment.

Embodiment 4 FIG.
FIG. 11 is a refrigerant circuit diagram of an air conditioner according to Embodiment 4 of the present invention. Unlike the third embodiment, the air conditioner of the fourth embodiment includes a supercooling bypass pipe 70 instead of the supercooling injection pipe 55. The subcooling bypass pipe 70 is branched from the point where the sub four-way valve 1 and the first subcooling heat exchanger 53 are reached (point B), and the subcooling decompression device 54 and the first subcooling heat exchanger are branched. 53, a supercooling on-off valve 56, a supercooling check valve 57, and a supercooling capillary tube 58 are connected to a suction pipe 35 connected to the compressor 23.
Moreover, in the figure, the solid line arrows indicate the flow direction of the refrigerant during the cooling operation, and the broken line arrows indicate the flow direction of the refrigerant during the heating operation. In the figure, each of the four-way valves 1 and 24 shows a state during cooling operation.

Hereinafter, the operation of the refrigerant circuit when the air-conditioning apparatus shown in Embodiment 4 performs the cooling operation and the heating operation will be described with reference to FIGS. 11 and 12.
FIG. 12 is a pressure-enthalpy diagram, where the solid line indicates the operation of the refrigerant circuit of the air conditioner shown in the fourth embodiment, and the alternate long and short dash line (the line connecting A-B-C-D-A). The operation | movement of the refrigerant circuit of the conventional air conditioner shown in FIG. A to I in the figure correspond to points A to I shown in FIGS. 11 and 29.

First, a case where the air conditioner performs a cooling operation will be described.
The operation of the conventional air conditioner is the same as the conventional operation shown in FIG. 8, and in FIG. 12, the inclination of the straight line from the point C to the point D is emphasized as compared with the case of FIG.
On the other hand, in the air conditioner shown in the fourth embodiment, the electromagnetic valve 43 is driven, the discharge side connection port 44 and the first connection port 46 communicate with each other, and the suction side connection port 45 and the second connection port 47. The main four-way valve 24 is switched so as to communicate with each other. Further, the supercooling on / off valve 56 is opened.
When the compressor 23 is driven, the fourth pipe 7 of the subordinate four-way valve 1 communicating with the discharge side of the compressor 23 becomes high pressure, while the third pipe of the subordinate four-way valve 1 communicating with the suction side of the compressor 23 is increased. The pipe 6 has a low pressure. Therefore, the switching valve 12 moves to the first end cover 19 side from the operation of the dependent four-way valve 1 described above, and the state shown in FIG. 1 is established, and the first pipe 4 and the fourth pipe 7 are connected to the valve chamber 3. The second pipe 5 and the third pipe 6 communicate with each other via the return channel 11a.

  The high-pressure refrigerant vapor (point A) discharged from the compressor 23 proceeds to the outdoor heat exchanger 25 via the main four-way valve 24, and is cooled by the outdoor air in the outdoor heat exchanger 25, which is a condenser, and condensed. Is done. The condensed refrigerant liquid passes through the dependent four-way valve 1 (point B), and is further cooled by an intermediate-pressure refrigerant flowing oppositely in the first subcooling heat exchanger 53 (point E). After being depressurized by the decompression device 30 (point F), the process proceeds to the indoor heat exchanger 26 via the subordinate four-way valve 1, and evaporates by taking heat from the indoor air in the indoor heat exchanger 26 that is an evaporator. At this time, as can be seen from the saturation vapor pressure curve W, the proportion of the refrigerant vapor that does not contribute to evaporation is smaller at the point F than the proportion of the refrigerant vapor at the point C. Therefore, the indoor heat exchanger together with the refrigerant liquid There are few refrigerant | coolants vapor | steam which flows in into 26, and the pressure loss (P1-P2) before and behind a refrigerant | coolant passing the indoor heat exchanger 26 becomes smaller than the pressure loss (P1-P3) of a prior art example. The refrigerant vapor evaporated in the indoor heat exchanger 26 passes through the main four-way valve 24 (point G) and then proceeds to the compressor 23.

  On the other hand, a part of the refrigerant liquid branched into the supercooling bypass pipe 70 at the point B is decompressed to an intermediate pressure by the supercooling decompression device 54 (point H), and then the first supercooling heat exchanger 53. The heat is removed from the high-pressure refrigerant flowing in the opposite direction and evaporated (point I), and then proceeds to the supercooling capillary tube 58 via the supercooling on-off valve 56 and the supercooling check valve 57, and the supercooling capillary tube After being depressurized at 58, it merges with the refrigerant vapor that has passed through the main four-way valve 24 (point G) and flows into the compressor 23. The refrigerant vapor that has flowed into the compressor 23 is compressed to point A and discharged again.

When the air conditioner shown in Embodiment 4 is air-cooled, the first subcooling heat exchanger 53 is provided, so that the enthalpy difference (h3-h1) of the indoor heat exchanger 26 that is an evaporator is the conventional air. It becomes larger than the enthalpy difference (h3-h2) of the harmony machine. Therefore, the evaporation capacity, that is, the cooling capacity is increased as compared with the conventional example.
Further, the pressure loss of the indoor heat exchanger 26 as an evaporator is reduced, and the suction pressure of the compressor 23 is increased. Therefore, when the air conditioner is operated so that the evaporation capacity is constant, the input of the compressor 23 decreases, and the coefficient of performance during cooling operation obtained by dividing the evaporation capacity by the input of the compressor 23 is conventionally More than the example.

Next, the heating operation will be described. The shape of the pressure-enthalpy diagram when the heating operation is performed is almost the same as FIG. However, in the conventional air conditioner shown in FIG. 29, the point B and the point C are interchanged.
The solenoid valve 43 is driven to switch the main four-way valve 24 so that the discharge side connection port 44 and the second connection port 47 communicate with each other and the suction side connection port 45 and the first connection port 46 communicate with each other. Further, the gas-liquid separating on-off valve 56 is opened.
When the compressor 23 is driven, the third pipe 6 of the subordinate four-way valve 1 that communicates with the discharge side of the compressor 23 becomes high pressure, while the fourth pipe of the subordinate four-way valve 1 that communicates with the suction side of the compressor 23. The piping 7 becomes a low pressure. Therefore, the switching valve 12 moves to the second end cover 20 side from the operation of the subordinate four-way valve 1 described above, and the state shown in FIG. 2 is established. The second pipe 5 and the fourth pipe 7 communicate with each other via the folded flow path 11a.

The high-pressure refrigerant vapor (point A) discharged from the compressor 23 proceeds to the indoor heat exchanger 26 via the main four-way valve 24, and is cooled by indoor air in the indoor heat exchanger 26 that is a condenser. , Condensed. After the condensed refrigerant liquid passes through the dependent four-way valve 1 (point B), it is further cooled by the intermediate pressure refrigerant flowing oppositely in the first subcooling heat exchanger 53 (point E), After being depressurized by the decompression device 30 (point F), the process proceeds to the outdoor heat exchanger 25 via the dependent four-way valve 1 and evaporates by taking heat from the outside air in the outdoor heat exchanger 25 that is an evaporator. The evaporated refrigerant vapor passes through the main four-way valve 24 (point G) and then proceeds to the compressor 23.
On the other hand, a part of the refrigerant liquid branched into the supercooling bypass pipe 70 at point B is decompressed to an intermediate pressure by the supercooling decompression device 54 (point H), and then the first supercooling heat exchanger 53. The heat is removed from the high-pressure refrigerant flowing in the opposite direction to evaporate (point I), and proceeds to the supercooling capillary tube 58 via the supercooling on-off valve 56 and supercooling check valve 57, and the supercooling capillary tube After being decompressed at 58, the refrigerant vapor that has passed through the main four-way valve 24 is merged (point G) and flows into the compressor 23. The refrigerant vapor that has flowed into the compressor 23 is compressed to point A and discharged again.

When the air conditioner shown in Embodiment 4 is operated for heating, the pressure loss (P1-P2) of the outdoor heat exchanger 25 serving as an evaporator is reduced, so that the intake temperature of the compressor rises and the air conditioner Refrigerant circulation flow rate increases. For this reason, the condensing capacity, that is, the heating capacity is increased as compared with the conventional example.
Further, when the air conditioner is operated so that the condensing capacity becomes constant due to the increase of the suction pressure of the compressor (P2-P3), the input of the compressor is reduced, and the condensing capacity is input to the compressor 23. The coefficient of performance at the time of heating operation obtained by dividing by is increased from the conventional example.

  As described above, the subordinate four-way valve 1 used in the air conditioner of the fourth embodiment has the configuration shown in FIGS. 1 and 2, and thus the subordinate four-way valve 1 was used for cooling operation and heating operation. In this case, the switching valve 12 of the dependent four-way valve 1 can be automatically switched in response to a pressure difference between the third pipe 6 and the fourth pipe 7 without using an electromagnetic valve that controls only the dependent four-way valve 1. it can. As a result, it is possible to reduce the number of solenoid valves used in the air conditioner, the control unit for operating the solenoid valves, and the wiring, so that the air conditioner can be made compact, and the control is simplified and the cost is reduced. Can be realized.

  In the air conditioner shown in the fourth embodiment, the decompression path 22 includes the first decompression device 30 and the first subcooling heat exchanger 53, and the subordinate four-way valve is disposed at both ends of the decompression path 22. 1 and a path for flowing the high-pressure refrigerant to the first decompression device 30 before the high-pressure refrigerant flows into the first decompression device 30 in both the cooling operation and the heating operation, and a supercooling decompression device The pressure is reduced to an intermediate pressure by 54 and branched to a subcooling bypass path that returns to the compressor 23. Further, the first supercooling heat exchanger 53 is provided so that the refrigerant after passing through the supercooling decompression device 54 and the refrigerant flowing into the first decompression device 30 exchange heat. Therefore, the capacity and the coefficient of performance can be increased in both the cooling operation and the heating operation of the air conditioner.

  Further, in both the cooling operation and the heating operation, the high-pressure refrigerant and the intermediate-pressure refrigerant branched in front of the first supercooling heat exchanger 53 by the switching of the switching valve 12 of the subordinate four-way valve 1 are the first refrigerant. Therefore, the heat exchange performance of the first supercooling heat exchanger 53 can be improved.

  Further, in both the cooling operation and the heating operation, the pressure in the valve chamber 3 of the subordinate four-way valve 1 becomes higher than the pressure in the return flow path 11a, and the valve body 11 is strongly pressed against the valve seat 21. However, there is no shortcut from the fourth pipe 7 to the second pipe 5 in the dependent four-way valve 1, and a refrigerant circuit for performing a desired operation can be formed.

In addition, the structure of the 1st subcooling heat exchanger 53 is arbitrary, and the refrigerant | coolant which has a different pressure should just be heat-exchangeable.
Further, in the present embodiment, the flow of the high-pressure refrigerant and the intermediate-pressure refrigerant that passes through the first subcooling heat exchanger 53 is opposed, but it may be parallel flow.
In the present embodiment, the description of the reheat dehumidification operation is omitted, but the reheat dehumidification operation can be performed by making the configuration of the indoor heat exchanger 26 the same as in the first embodiment.
Further, instead of the supercooling on-off valve 56, the supercooling check valve 57, and the supercooling capillary tube 58, a supercooling flow rate control valve is provided so that the flow rate of the refrigerant vapor passing through the supercooling bypass pipe 70 is increased. You may adjust.

Embodiment 5 FIG.
13 is a refrigerant circuit diagram of an air conditioner according to Embodiment 5 of the present invention. In the air conditioner of the fifth embodiment, unlike the first embodiment, the decompression path 22 does not include the second decompression device 31, and the first decompression device 30 and the gas-liquid separator 32 (first And an ejector 61 (provided on the upstream side of the gas-liquid separator 32). Further, the main path includes the subordinate four-way valve 1 so that the flow direction of the refrigerant passing through the decompression path 22 is constant in both the cooling operation and the heating operation.
The ejector 61 includes a nozzle 59 and a diffuser 60, and the nozzle 59 and the diffuser 60 are connected to the suction pipe 35 by an ejector pipe 62. The ejector pipe 62 includes an ejector decompression device 63.
Further, similarly to the first embodiment, a gas injection pipe 36 for returning the gas-phase refrigerant separated by the gas-liquid separator 32 to the intermediate compression process of the compressor 23 is provided.
Moreover, in the figure, the solid line arrows indicate the flow direction of the refrigerant during the cooling operation, and the broken line arrows indicate the flow direction of the refrigerant during the heating operation. In the figure, each of the four-way valves 1 and 24 shows a state during cooling operation.

Hereinafter, the operation of the refrigerant circuit when the air-conditioning apparatus shown in Embodiment 5 performs the cooling operation and the heating operation will be described with reference to FIGS. 13 and 14.
FIG. 14 is a pressure-enthalpy diagram, where the solid line indicates the operation of the refrigerant circuit of the air conditioner shown in the fifth embodiment, and the alternate long and short dash line (the line connecting A-B-C-D-A). The operation | movement of the refrigerant circuit of the conventional air conditioner shown in FIG. A to L in the figure correspond to points A to L shown in FIGS. 13 and 29.

First, a case where the air conditioner performs a cooling operation will be described.
The operation of the conventional air conditioner is the same as that of the conventional operation shown in FIG. 6, and in FIG. 14, the inclination of the straight line from the C point to the D point is ignored.
On the other hand, in the air conditioner shown in the fifth embodiment, the solenoid valve 43 is driven, the discharge side connection port 44 and the first connection port 46 communicate with each other, and the suction side connection port 45 and the second connection port 47 are connected. The main four-way valve 24 is switched so as to communicate with each other.
When the compressor 23 is driven, the fourth pipe 7 of the subordinate four-way valve 1 communicating with the discharge side of the compressor 23 becomes high pressure, while the third pipe of the subordinate four-way valve 1 communicating with the suction side of the compressor 23 is increased. The pipe 6 has a low pressure. For this reason, the switching valve 12 moves to the first end cover 19 side from the operation of the above-described subordinate four-way valve 1 to the state shown in FIG. 1, and the first pipe 4 and the fourth pipe 7 are connected to the valve chamber. 3, the second pipe 5 and the third pipe 6 communicate with each other via the folded flow path 11 a.

  The high-pressure refrigerant vapor (point E) discharged from the compressor 23 proceeds to the outdoor heat exchanger 25 through the main four-way valve 24, and is cooled by the outdoor air in the outdoor heat exchanger 25, which is a condenser, and condensed. Is done. The condensed refrigerant liquid passes through the subordinate four-way valve 1 (point B) and then expands and accelerates while changing the isentropy at the nozzle 59 of the ejector 61 (point F). The refrigerant vapor (point D) that has passed through 62 is attracted and mixed (point G), and the pressure is recovered by the diffuser 60 (point H). The pressure-recovered refrigerant flows into the gas-liquid separator 32 in a gas-liquid two-phase state, and is separated into refrigerant vapor (point L) and refrigerant liquid (point I). The separated refrigerant liquid is the first decompression device. After the pressure is further reduced at 30 (point J), it flows into the indoor heat exchanger 26 via the dependent four-way valve 1. The refrigerant evaporates by taking heat from indoor air in the indoor heat exchanger 26 that is an evaporator, and flows into the compressor 23 through the main four-way valve 24 (point K).

On the other hand, the flow rate of the intermediate-pressure refrigerant vapor (point L) separated by the gas-liquid separator 32 is adjusted by the injection flow control valve 33, passes through the injection pipe 36, and is in the middle of the compression process of the compressor 23 ( The refrigerant at point L and the refrigerant at point M are mixed (point N). Further, the refrigerant is compressed to point E and discharged again.
Further, the refrigerant vapor after evaporating in the indoor heat exchanger 26 and passing through the main four-way valve 24 (point K) is branched from the middle of the suction pipe 35 to the ejector pipe 62 and decompressed by the ejector decompression device 63. Later (D point), it is attracted and mixed by the high-speed refrigerant (F point) that has passed through the nozzle 59 (G point).

When the air conditioner shown in Embodiment 5 is air-cooled, the ejector 61 and the gas-liquid separator 32 are provided. Therefore, the enthalpy difference (h3-h1) of the indoor heat exchanger 26 that is an evaporator is the conventional air conditioner. It becomes larger than the enthalpy difference (h3-h2) of the machine. Therefore, the evaporation capacity, that is, the cooling capacity is increased as compared with the conventional example.
Further, when the air conditioner is operated so that the evaporation capacity is constant, the input of the compressor 23 is reduced by the pressure increase (P1-P2) due to the use of the ejector 61, and the evaporation capacity is reduced to the compressor 23. The coefficient of performance at the time of cooling operation obtained by dividing by the input is increased as compared with the conventional example.
Further, since the ejector pipe 62 is provided, a part of the refrigerant vapor evaporated by the indoor heat exchanger 26 is sucked by the ejector 61, boosted by the diffuser 60, separated by the gas-liquid separator 32, and injected by the injection pipe 36. To the compressor 23. Thereby, the input to the compressor 23 decreases.
Further, since the temperature (point E) when discharged from the compressor 23 is lower than that of the conventional example (point A), the reliability of the compressor 23 is improved.

Next, the heating operation will be described. The shape of the pressure-enthalpy diagram when the heating operation is performed is almost the same as that in FIG. However, in the conventional air conditioner shown in FIG. 29, the point B and the point C are interchanged.
The solenoid valve 43 is driven to switch the main four-way valve 24 so that the discharge side connection port 44 and the second connection port 47 communicate with each other and the suction side connection port 45 and the first connection port 46 communicate with each other.
When the compressor 23 is driven, the third pipe 6 of the subordinate four-way valve 1 that communicates with the discharge side of the compressor 23 becomes high pressure, while the fourth pipe of the subordinate four-way valve 1 that communicates with the suction side of the compressor 23. The piping 7 becomes a low pressure. Therefore, the switching valve 12 moves to the second end cover 20 side from the operation of the subordinate four-way valve 1 described above, and the state shown in FIG. 2 is established. The second pipe 5 and the fourth pipe 7 communicate with each other via the folded flow path 11a.

  The high-pressure refrigerant vapor (point E) discharged from the compressor 23 proceeds to the indoor heat exchanger 26 via the main four-way valve 24 and is cooled by indoor air in the indoor heat exchanger 26 that is a condenser. , Condensed. The condensed refrigerant liquid passes through the subordinate four-way valve 1 (point B), then expands and accelerates while changing the isentropy at the nozzle 59 (point F), and passes through the ejector pipe 62 at the inlet of the diffuser 60. The refrigerant vapor (D point) is attracted and mixed (G point), and the pressure is restored by the diffuser 60 (H point). The pressure-recovered refrigerant flows into the gas-liquid separator 32 in a gas-liquid two-phase state, and is separated into refrigerant vapor (point L) and refrigerant liquid (point I). The separated refrigerant liquid is the first decompression device. After the pressure is further reduced at 30 (point J), the refrigerant flows into the outdoor heat exchanger 25 via the dependent four-way valve 1. The refrigerant evaporates by taking heat from the outside air in the outdoor heat exchanger 25 that is an evaporator, and flows into the compressor 23 through the main four-way valve 24 (point K).

On the other hand, the flow rate of the intermediate-pressure refrigerant vapor (point L) separated by the gas-liquid separator 32 is adjusted by the injection flow control valve 33, passes through the injection pipe 36, and is in the middle of the compression process of the compressor 23 ( The refrigerant at point L and the refrigerant at point M are mixed (point N). Further, the refrigerant is compressed to point E and discharged again.
The refrigerant vapor after passing through the main four-way valve 24 (point K) is branched from the middle of the suction pipe 35 to the ejector pipe 62 and decompressed by the ejector decompression device 63 (point D). It is attracted and mixed by the high-speed refrigerant (F point) that has passed (G point).

When the air conditioner shown in Embodiment 5 is heated and operated, since it has the injection pipe 36, the refrigerant flow rate flowing through the indoor heat exchanger 26 that is a condenser is the refrigerant flow rate injected into the compressor 23 from the injection pipe 36. Increase by. For this reason, the condensing capacity, that is, the heating capacity is increased as compared with the conventional example.
Moreover, since the temperature when discharged from the compressor 23 is lower than that of the conventional example, the reliability of the compressor 23 is improved.
Further, when the air conditioner is operated so that the condensing capacity is constant, since the ejector 61 is provided, the input of the compressor 23 is reduced by the pressure increase (P1-P2) due to the use of the ejector 61, The coefficient of performance at the time of heating operation obtained by dividing the condensation capacity by the input of the compressor 23 is increased as compared with the conventional example.
Further, since the ejector pipe 62 is provided, a part of the refrigerant vapor evaporated by the outdoor heat exchanger 25 is sucked by the ejector 61, boosted by the diffuser 60, separated by the gas-liquid separator 32, and injected by the injection pipe 36. To the compressor 23. Thereby, the input to the compressor 23 decreases.

  As described above, the subordinate four-way valve 1 used in the air conditioner of the fifth embodiment has the configuration shown in FIGS. 1 and 2, and thus the subordinate four-way valve 1 was used for cooling operation and heating operation. In this case, the switching valve 12 of the dependent four-way valve 1 can be automatically switched in response to a pressure difference between the third pipe 6 and the fourth pipe 7 without using an electromagnetic valve that controls only the dependent four-way valve 1. it can. As a result, it is possible to reduce the number of solenoid valves used in the air conditioner, the control unit for operating the solenoid valves, and the wiring, so that the air conditioner can be made compact, and the control is simplified and the cost is reduced. Can be realized.

  In the air conditioner shown in the fifth embodiment, the decompression path 22 includes the first decompression device 30, the gas-liquid separator 32, and the ejector 61, and the subordinate four-way valve 1 is disposed at both ends of the decompression path 22. In both the cooling operation and the heating operation, the high-pressure refrigerant flows into the ejector 61, expands by isentropic change at the nozzle 59, and sucks the refrigerant vapor through the ejector pipe 62. After the pressure is recovered by the diffuser 60, it flows into the gas-liquid separator 32 in a gas-liquid two-phase state, and is further separated into the refrigerant vapor and the refrigerant liquid by the gas-liquid separator 32. So that the ejector 61 and the gas-liquid separator 32 function such that the refrigerant is depressurized by the first pressure reducing device 30 after flowing out and the separated refrigerant vapor flows out through the gas-liquid separating pipe 49. It is possible to form a flow of refrigerant work. Therefore, in both the cooling operation and the heating operation of the air conditioner, the capacity and the coefficient of performance can be increased, and the reliability of the compressor is improved.

  Further, in both the cooling operation and the heating operation, the pressure in the valve chamber 3 of the subordinate four-way valve 1 becomes higher than the pressure in the return flow path 11a, and the valve body 11 is strongly pressed against the valve seat 21. However, there is no shortcut from the fourth pipe 7 to the second pipe 5 in the dependent four-way valve 1, and a refrigerant circuit for performing a desired operation can be formed.

  In addition, although the ejector 61 provided with the nozzle 59 and the diffuser 60 was shown here, what is necessary is just an expansion mechanism which can collect | recover expansion power.

  In the present embodiment, the description of the reheat dehumidification operation is omitted, but the reheat dehumidification operation can be performed by making the configuration of the indoor heat exchanger 26 the same as in the first embodiment.

Embodiment 6 FIG.
FIG. 15 is a refrigerant circuit diagram of an air conditioner according to Embodiment 6 of the present invention. The air conditioner of the sixth embodiment is different from the fifth embodiment in that the suction side connection port 45 of the main four-way valve 24 is not connected to the suction pipe 35 but is connected to the ejector pipe 62. In addition, the injection pipe 36 and the injection flow control valve 33 are not provided. Instead, the gas-liquid separator 32 and the suction pipe 35 are connected by a gas-liquid separation return pipe 71 for gas-liquid separation. The return pipe 71 includes a gas-liquid separation return flow valve 64.
Moreover, in the figure, the solid line arrows indicate the flow direction of the refrigerant during the cooling operation, and the broken line arrows indicate the flow direction of the refrigerant during the heating operation. In the figure, each of the four-way valves 1 and 24 shows a state during cooling operation.

Hereinafter, the operation of the refrigerant circuit when the air-conditioning apparatus shown in Embodiment 6 performs the cooling operation and the heating operation will be described with reference to FIGS. 15 and 16.
FIG. 16 is a pressure-enthalpy diagram, where the solid line indicates the operation of the refrigerant circuit of the air conditioner shown in the sixth embodiment, and the alternate long and short dash line (the line connecting A-B-C-D-A). The operation | movement of the refrigerant circuit of the conventional air conditioner shown in FIG. A to K in the figure correspond to points A to K shown in FIGS. 15 and 29.

First, a case where the air conditioner performs a cooling operation will be described.
The operation of the conventional air conditioner is the same as that of the conventional operation shown in FIG. 6, and in FIG. 16, the inclination of the straight line from the point C to the point D is ignored.
On the other hand, in the air conditioner shown in the sixth embodiment, the solenoid valve 43 is driven, the discharge side connection port 44 and the first connection port 46 communicate with each other, and the suction side connection port 45 and the second connection port 47 are connected. The main four-way valve 24 is switched so as to communicate with each other.
When the compressor 23 is driven, the fourth pipe 7 of the subordinate four-way valve 1 communicating with the discharge side of the compressor 23 becomes high pressure, while the gas-liquid separation return pipe 71 and the gas pipe are connected to the suction side of the compressor 23. The third pipe 6 of the subordinate four-way valve 1 communicating with the liquid separator 32, the diffuser 60, the ejector pipe 62, the main four-way valve 24, the indoor side gas pipe 39, the indoor heat exchanger 26, and the indoor side liquid pipe 40. Becomes low pressure. For this reason, the switching valve 12 moves to the first end cover 19 side from the operation of the above-described subordinate four-way valve 1 to the state shown in FIG. 1, and the first pipe 4 and the fourth pipe 7 are connected to the valve chamber. 3, the second pipe 5 and the third pipe 6 communicate with each other via the folded flow path 11 a.

The high-pressure refrigerant vapor (point A) discharged from the compressor 23 proceeds to the outdoor heat exchanger 25 via the main four-way valve 24, and is cooled by the outdoor air in the outdoor heat exchanger 25, which is a condenser, and condensed. Is done. The condensed refrigerant liquid passes through the dependent four-way valve 1 (point B), and then expands and accelerates while changing the isentropy at the nozzle 59 of the ejector 61 (point E). The refrigerant vapor (point D) that has passed through 62 is attracted and mixed (point F), and the pressure is recovered by the diffuser 60 (point G). The refrigerant whose pressure has been recovered flows into the gas-liquid separator 32 in a gas-liquid two-phase state, and is separated into refrigerant vapor (point K) and refrigerant liquid (point H). The separated refrigerant liquid is the first decompression device. After further depressurization at 30 (point I), it flows into the indoor heat exchanger 26 via the dependent four-way valve 1. The refrigerant takes the heat from the indoor air by the indoor heat exchanger 26 as an evaporator, evaporates, passes through the main four-way valve 24 (point J), passes through the ejector pipe 62, and is ejected by the decompressor 63 for ejector. The pressure is reduced (point D) and is attracted and mixed by the high-speed refrigerant (point E) that has passed through the nozzle 59 (point F). That is, the refrigerant flow rate circulating through the indoor heat exchanger 26 is all the flow rate attracted by the ejector 61.
The refrigerant vapor separated by the gas-liquid separator 32 flows into the compressor 23 through the gas-liquid separation return pipe 71 via the gas-liquid separation return flow valve 64 (point K).

When the air conditioner shown in Embodiment 6 is air-cooled, the gas-liquid separator 32 is provided, so that the enthalpy difference (h3-h1) of the indoor heat exchanger 26 that is an evaporator is enthalpy of the conventional air conditioner. It becomes larger than the difference (h3−h2). Therefore, the evaporation capacity, that is, the cooling capacity is increased as compared with the conventional example.
Further, when the air conditioner is operated so that the evaporation capacity becomes constant, the ejector 61 is provided, so that the input of the compressor 23 is reduced by the pressure increase (P1-P2) due to the use of the ejector 61, The coefficient of performance during cooling operation obtained by dividing the evaporation capacity by the input of the compressor 23 is increased as compared with the conventional example.
Further, since the ejector pipe 62 is provided, the refrigerant vapor evaporated by the indoor heat exchanger 26 is sucked by the ejector 61, and the refrigerant can be circulated through the indoor heat exchanger 26.

Next, the heating operation will be described. The shape of the pressure-enthalpy diagram when the heating operation is performed is almost the same as that in FIG. However, in the conventional air conditioner shown in FIG. 29, the point B and the point C are interchanged.
The solenoid valve 43 is driven to switch the main four-way valve 24 so that the discharge side connection port 44 and the second connection port 47 communicate with each other and the suction side connection port 45 and the first connection port 46 communicate with each other.
When the compressor 23 is driven, the third pipe 6 of the subordinate four-way valve 1 communicating with the discharge side of the compressor 23 becomes high pressure, while the gas-liquid separation return pipe 71 and the gas pipe are connected to the suction side of the compressor 23. The fourth pipe 7 of the subordinate four-way valve 1 communicated via the liquid separator 32, the diffuser 60, the ejector pipe 62, the main four-way valve 24, the outdoor gas pipe 37, the outdoor heat exchanger 25, and the outdoor liquid pipe 38. Becomes low pressure. Therefore, the switching valve 12 moves to the second end cover 20 side from the operation of the subordinate four-way valve 1 described above, and the state shown in FIG. 2 is established. The second pipe 5 and the fourth pipe 7 communicate with each other via the folded flow path 11a.

The high-pressure refrigerant vapor (point A) discharged from the compressor 23 proceeds to the indoor heat exchanger 26 via the main four-way valve 24 and is cooled by indoor air in the indoor heat exchanger 25 that is a condenser. , Condensed. The condensed refrigerant liquid passes through the subordinate four-way valve 1 (point B), then expands and accelerates while changing the isentropy at the nozzle 59 (point E), and passes through the ejector pipe 62 at the inlet of the diffuser 60. The refrigerant vapor (point D) is attracted and mixed (point F), and the pressure is restored by the diffuser 60 (point G). The refrigerant whose pressure has been recovered flows into the gas-liquid separator 32 in a gas-liquid two-phase state, and is separated into refrigerant vapor (point K) and refrigerant liquid (point H). The separated refrigerant liquid is the first decompression device. After the pressure is further reduced at 30 (point I), it flows into the outdoor heat exchanger 25 via the dependent four-way valve 1. The refrigerant evaporates by taking heat from the outside air in the outdoor heat exchanger 25 that is an evaporator, passes through the main four-way valve 24 (point J), passes through the ejector piping 62, and is decompressed by the ejector decompression device 63. (D point), the high-speed refrigerant (point E) that has passed through the nozzle 59 is attracted and mixed (point F). That is, the refrigerant flow rate circulating through the outdoor heat exchanger 25 is all the flow rate attracted by the ejector 61.
The refrigerant vapor separated by the gas-liquid separator 32 flows into the compressor 23 through the gas-liquid separation return pipe 71 via the gas-liquid separation return flow valve 64 (point K).

When the air conditioner shown in Embodiment 6 is operated for heating, since the ejector 61 is provided, the input of the compressor 23 is reduced by a pressure increase (P1-P2) due to the use of the ejector 61. Therefore, when the air conditioner is operated so that the condensing capacity is constant, the coefficient of performance during the heating operation obtained by dividing the condensing capacity by the input of the compressor 23 is increased as compared with the conventional example.
Further, since the ejector pipe 62 is provided, the refrigerant vapor evaporated by the outdoor heat exchanger 25 is sucked by the ejector 61, and the refrigerant can be circulated through the outdoor heat exchanger 25.

  As described above, the subordinate four-way valve 1 used in the air conditioner of the sixth embodiment has the configuration shown in FIGS. 1 and 2, and thus the subordinate four-way valve 1 was used for cooling operation and heating operation. In this case, the switching valve 12 of the dependent four-way valve 1 can be automatically switched in response to a pressure difference between the third pipe 6 and the fourth pipe 7 without using an electromagnetic valve that controls only the dependent four-way valve 1. it can. As a result, it is possible to reduce the number of solenoid valves used in the air conditioner, the control unit for operating the solenoid valves, and the wiring, so that the air conditioner can be made compact, and the control is simplified and the cost is reduced. Can be realized.

  In the air conditioner shown in the sixth embodiment, the decompression path 22 includes the first decompression device 30, the gas-liquid separator 32, and the ejector 61, and the subordinate four-way valve 1 is disposed at both ends of the decompression path 22. In both the cooling operation and the heating operation, the high-pressure refrigerant flows into the ejector 61, expands by isentropic change at the nozzle 59, and sucks the refrigerant vapor through the ejector pipe 62. After the pressure is recovered by the diffuser 60, it flows into the gas-liquid separator 32 in a gas-liquid two-phase state, and is further separated into the refrigerant vapor and the refrigerant liquid by the gas-liquid separator 32. The ejector 61 and the gas-liquid separator 32 function such that the refrigerant is decompressed by the first decompression device 30 after flowing out and the separated refrigerant vapor flows out through the gas-liquid separating return pipe 71. It is possible to form a flow of the refrigerant that operates. Therefore, the coefficient of performance can be increased in both the cooling operation and the heating operation of the air conditioner.

  Further, in both the cooling operation and the heating operation, the pressure in the valve chamber 3 of the subordinate four-way valve 1 becomes higher than the pressure in the return flow path 11a, and the valve body 11 is strongly pressed against the valve seat 21. However, there is no shortcut from the fourth pipe 7 to the second pipe 5 in the dependent four-way valve 1, and a refrigerant circuit for performing a desired operation can be formed.

  In addition, although the ejector 61 provided with the nozzle 59 and the diffuser 60 was shown here, what is necessary is just an expansion mechanism which can collect | recover expansion power.

In the present embodiment, the description of the reheat dehumidification operation is omitted, but the reheat dehumidification operation can be performed by making the configuration of the indoor heat exchanger 26 the same as in the first embodiment.
Further, in the air conditioner of the sixth embodiment, at least one of the first decompressor 30 and the ejector decompressor 63 may be deleted. In this case, pressure loss from the liquid refrigerant outlet of the gas-liquid separator 32 to the sub four-way valve 1, the indoor heat exchanger 26 (or the outdoor heat exchanger 25), the main four-way valve 24, and the nozzle 59 is reduced. Thus, the amount of refrigerant attracted by the high-speed refrigerant (point E) after passing through the nozzle 59 can be increased, and the heat exchange amount of the indoor heat exchanger 26 can be improved.
In the air conditioner of the sixth embodiment, the gas-liquid separation return flow valve 64 may be deleted. In this case, since the pressure loss from the refrigerant vapor outlet of the gas-liquid separator 32 to the inlet of the compressor 23 can be reduced, the suction pressure of the compressor 23 is increased and the electric input of the compressor 23 is increased. Can be reduced.
Moreover, in the air conditioner of the sixth embodiment, the example in which the first pressure reducing device 30 is provided between the gas-liquid separator 32 and the subordinate four-way valve 1 has been shown, but the first pressure reducing device 30 is provided as the subordinate four-way valve. 1 and the ejector 61 or between the ejector 61 and the gas-liquid separator 32. By providing the first decompression device 30 in the decompression path 22, it is possible to adjust the amount of decompression that cannot be controlled by the ejector 61.

Embodiment 7 FIG.
FIG. 17 is a refrigerant circuit diagram of an air conditioner according to Embodiment 7 of the present invention. The air conditioner of the seventh embodiment is different from the first embodiment in that the decompression path 22 is not provided with the gas-liquid separator 32, and the first decompressor 30 and the first supercooling heat exchanger. 53 (provided downstream of the first decompressor 30), a second supercooling heat exchanger 65 (provided downstream of the first supercooling heat exchanger 53), and a second decompressor. 31 (provided on the downstream side of the second subcooling heat exchanger 65). Further, the main path includes the subordinate four-way valve 1 so that the flow direction of the refrigerant passing through the decompression path 22 is constant in both the cooling operation and the heating operation.
Further, in the seventh embodiment, the refrigerant branched from the time until it reaches the second subcooling heat exchanger 65 downstream of the first subcooling heat exchanger 53 is returned to the intermediate compression process of the compressor 23. A supercooling injection pipe 55 is provided. The supercooling injection pipe 55 is provided with a supercooling decompression device 54 for setting the branched refrigerant to an intermediate pressure, and the refrigerant after passing through the supercooling decompression device 54 and the first decompression device 30. The refrigerant after passing through the heat exchanger exchanges heat via the first supercooling heat exchanger 53. Further, the refrigerant flowing into the second decompression device 31 and the refrigerant flowing into the compressor 23 exchange heat through the second subcooling heat exchanger 65.
Moreover, in the figure, the solid line arrows indicate the flow direction of the refrigerant during the cooling operation, and the broken line arrows indicate the flow direction of the refrigerant during the heating operation. In the figure, each of the four-way valves 1 and 24 shows a state during cooling operation.

Hereinafter, the operation of the refrigerant circuit when the air conditioner shown in Embodiment 7 performs the cooling operation and the heating operation will be described with reference to FIGS. 17 and 18.
FIG. 18 is a pressure-enthalpy diagram, where the solid line indicates the operation of the refrigerant circuit of the air conditioner shown in the seventh embodiment, and the alternate long and short dash line (the line connecting A-B-C-D-A). The operation | movement of the refrigerant circuit of the conventional air conditioner shown in FIG. A to L in the figure correspond to points A to L shown in FIGS. 17 and 29.

First, a case where the air conditioner performs a cooling operation will be described.
The operation of the conventional air conditioner is the same as the conventional operation shown in FIG. 6, and in FIG. 18, the inclination of the straight line from the C point to the D point is ignored.
On the other hand, in the air conditioner shown in the seventh embodiment, the solenoid valve 43 is driven, the discharge side connection port 44 and the first connection port 46 communicate with each other, and the suction side connection port 45 and the second connection port 47 are connected. The main four-way valve 24 is switched so as to communicate with each other.
When the compressor 23 is driven, the fourth pipe 7 of the subordinate four-way valve 1 communicating with the discharge side of the compressor 23 becomes high pressure, while the third pipe of the subordinate four-way valve 1 communicating with the suction side of the compressor 23 is increased. The pipe 6 has a low pressure. Therefore, the switching valve 12 moves to the first end cover 19 side from the operation of the dependent four-way valve 1 described above, and the state shown in FIG. 1 is established, and the first pipe 4 and the fourth pipe 7 are connected to the valve chamber 3. The second pipe 5 and the third pipe 6 communicate with each other via the return channel 11a.

  The high-pressure refrigerant vapor (point E) discharged from the compressor 23 proceeds to the outdoor heat exchanger 25 via the main four-way valve 24, and is cooled by the outdoor air in the outdoor heat exchanger 25, which is a condenser, and condensed. Is done. After the condensed refrigerant liquid passes through the subordinate four-way valve 1 (point B), it is depressurized by the first decompression device 30 (point F), and further flows through the first supercooling heat exchanger 53 in an opposite direction. It is cooled (point G) by the refrigerant with pressure P3 (points K to L). Thereafter, the refrigerant is further cooled by a low-pressure P4 refrigerant (point J to point D) that flows oppositely in the second subcooling heat exchanger 65 (point H to point D), and then decompressed by the second decompression device 31 (I Point), the process proceeds to the indoor heat exchanger 26 via the dependent four-way valve 1. The refrigerant takes the heat from the indoor air in the indoor heat exchanger 26 as an evaporator and evaporates, but does not completely evaporate and passes through the main four-way valve 24 in a gas-liquid two-phase state (point J). In the second subcooling heat exchanger 65, heat is taken from the refrigerant (G point to H point) at the intermediate pressure P2 to evaporate (D point), and the process proceeds to the compressor 23.

  On the other hand, a part of the refrigerant liquid branched to the supercooling injection pipe 55 at the point G is decompressed to the intermediate pressure P3 by the supercooling decompression device 54 (point K), and then the first supercooling heat exchanger. Although the heat is removed from the refrigerant (point F to point G) of the intermediate pressure P2 that flows oppositely at 53 (point L), it does not evaporate completely, and the compressor 23 of the compressor 23 is in a gas-liquid two-phase state. It is injected halfway (point M), and the refrigerant at point L and the refrigerant at point M are mixed (point N). Further, the refrigerant is compressed to point E and discharged again.

When the air conditioner shown in Embodiment 7 is air-cooled, the first subcooling heat exchanger 53 and the second subcooling heat exchanger 65 are provided, so the enthalpy difference of the indoor heat exchanger 26 that is an evaporator. (H3−h1) becomes larger than the enthalpy difference (h4−h2) of the conventional air conditioner. Therefore, the evaporation capacity, that is, the cooling capacity is increased as compared with the conventional example.
Further, since the supercooling injection pipe 55 is provided, the flow rate of the refrigerant flowing through the compressor 23 is increased by the flow rate of the refrigerant injected from the supercooling injection pipe 55 into the compressor 23. Therefore, although the input of the compressor 23 also increases, since the evaporation capacity is larger than that, the coefficient of performance during the cooling operation obtained by dividing the evaporation capacity by the input of the compressor 23 is increased as compared with the conventional example. Further, since the temperature when discharged from the compressor is lower than that of the conventional example, the reliability of the compressor is improved.

Next, the heating operation will be described. The shape of the pressure-enthalpy diagram when the heating operation is performed is substantially the same as FIG. However, when heating the conventional air conditioner shown in FIG. 29, the points B and C are interchanged.
The solenoid valve 43 is driven to switch the main four-way valve 24 so that the discharge side connection port 44 and the second connection port 47 communicate with each other and the suction side connection port 45 and the first connection port 46 communicate with each other.
When the compressor 23 is driven, the third pipe 6 of the subordinate four-way valve 1 that communicates with the discharge side of the compressor 23 becomes high pressure, while the fourth pipe of the subordinate four-way valve 1 that communicates with the suction side of the compressor 23. The piping 7 becomes a low pressure. Therefore, the switching valve 12 moves to the second end cover 20 side from the operation of the subordinate four-way valve 1 described above, and the state shown in FIG. 2 is established. The second pipe 5 and the fourth pipe 7 communicate with each other via the folded flow path 11a.

  The high-pressure refrigerant vapor (point E) discharged from the compressor 23 proceeds to the indoor heat exchanger 26 via the main four-way valve 24 and is cooled by indoor air in the indoor heat exchanger 26 that is a condenser. , Condensed. After the condensed refrigerant liquid passes through the subordinate four-way valve 1 (point B), it is depressurized by the first decompression device 30 (point F), and further flows through the first supercooling heat exchanger 53 in an opposite direction. It is cooled (point G) by the refrigerant with pressure P3 (points K to L). Thereafter, the refrigerant is further cooled by a low-pressure P4 refrigerant (point J to point D) that flows oppositely in the second subcooling heat exchanger 65 (point H to point D), and then decompressed by the second decompression device 31 (I Point), the process proceeds to the outdoor heat exchanger 25 via the subordinate four-way valve 1. The refrigerant takes heat from the outside air in the outdoor heat exchanger 25 that is an evaporator and evaporates, but does not completely evaporate, and after passing through the main four-way valve 24 in the gas-liquid two-phase state (point J), the second In the subcooling heat exchanger 65, heat is taken from the refrigerant having the intermediate pressure P2 (G point to H point) to evaporate (D point), and the process proceeds to the compressor 23.

  On the other hand, a part of the refrigerant liquid branched to the supercooling injection pipe 55 at the point G is decompressed to the intermediate pressure P3 by the supercooling decompression device 54 (point K), and then the first supercooling heat exchanger. Although the heat is removed from the refrigerant (point F to point G) of the intermediate pressure P2 that flows oppositely at 53 (point L), it does not evaporate completely, and the compressor 23 of the compressor 23 is in a gas-liquid two-phase state. It is injected halfway (point M), and the refrigerant at point L and the refrigerant at point M are mixed (point N). Further, the refrigerant is compressed to point E and discharged again.

When the air conditioner shown in Embodiment 7 is heated, the supercooling injection pipe 55 is provided, so that the refrigerant flow rate flowing through the indoor heat exchanger 26 as a condenser is changed from the supercooling injection pipe 55 to the compressor 23. It increases with the flow rate of the refrigerant injected into the tank. For this reason, the condensing capacity, that is, the heating capacity is increased as compared with the conventional example.
Further, the flow rate of the refrigerant flowing through the compressor 23 increases due to the flow rate of the refrigerant injected into the compressor 23 from the subcooling injection pipe 55. Therefore, although the input of the compressor 23 also increases, since the condensing capacity is larger than that, the coefficient of performance during the heating operation obtained by dividing the condensing capacity by the input of the compressor 23 is increased as compared with the conventional example. Further, since the temperature when discharged from the compressor is lower than that of the conventional example, the reliability of the compressor is improved.

  As described above, the subordinate four-way valve 1 used in the air conditioner of the seventh embodiment has the configuration shown in FIGS. 1 and 2, and thus the subordinate four-way valve 1 was used for cooling operation and heating operation. In this case, the switching valve 12 of the dependent four-way valve 1 can be automatically switched in response to a pressure difference between the third pipe 6 and the fourth pipe 7 without using an electromagnetic valve that controls only the dependent four-way valve 1. it can. As a result, it is possible to reduce the number of solenoid valves used in the air conditioner, the control unit for operating the solenoid valves, and the wiring, so that the air conditioner can be made compact, and the control is simplified and the cost is reduced. Can be realized.

  In the air conditioner shown in the seventh embodiment, the decompression path 22 is routed through the first decompression device 30, the first supercooling heat exchanger 53, the second supercooling heat exchanger 65, and the first 2, the sub four-way valve 1 is connected to both ends of the pressure reducing path 22, and the first supercooling heat exchanger 53 is connected to the supercooling injection pipe in both the cooling operation and the heating operation. The second subcooling heat exchanger 65 can exchange heat with the refrigerant passing through 55, and the second subcooling heat exchanger 65 can exchange heat with the refrigerant returning to the compressor. Therefore, ability and a coefficient of performance can be increased. Further, the reliability of the compressor 23 is improved.

  Further, in both the cooling operation and the heating operation, in the first subcooling heat exchanger 53 and the second subcooling heat exchanger 65, the refrigerant flowing in the heat exchanger is caused to flow oppositely. The heat exchange performance of the first subcooling heat exchanger 53 and the second subcooling heat exchanger 65 can be improved.

  Further, in both the cooling operation and the heating operation, the pressure in the valve chamber 3 of the subordinate four-way valve 1 becomes higher than the pressure in the return flow path 11a, and the valve body 11 is strongly pressed against the valve seat 21. However, there is no shortcut from the fourth pipe 7 to the second pipe 5 in the dependent four-way valve 1, and a refrigerant circuit for performing a desired operation can be formed.

  In addition, the structure of the 1st subcooling heat exchanger 53 and the 2nd subcooling heat exchanger 65 is arbitrary, and the refrigerant | coolant which has a different pressure should just be heat-exchangeable.

  In the present embodiment, the description of the reheat dehumidification operation is omitted, but the reheat dehumidification operation can be performed by making the configuration of the indoor heat exchanger 26 the same as in the first embodiment.

Embodiment 8 FIG.
FIG. 19 is a refrigerant circuit diagram of an air conditioner according to Embodiment 8 of the present invention. Unlike the first embodiment, the air conditioner of the eighth embodiment does not include the gas-liquid separator 32, the injection flow control valve 33, and the injection pipe 36. Instead, the expander 72, An expansion power transmission means 73, a sub compressor 74, an expansion bypass pipe 75, and an expansion flow control valve 76 are provided. Further, an expander 72 is connected between the first pressure reducing device 30 and the second pressure reducing device 31, and a sub compressor 74 is connected between the main four-way valve 24 and the suction side of the compressor 23, and the inflow An expansion bypass pipe 75 is connected to the pipe 41 and the outflow pipe 42, and an expansion flow control valve 76 is arranged in the expansion bypass pipe 75.
The expander 72 and the sub-compressor 74 are connected by an expansion power transmission means 73 so that the expansion power recovered by the expander 72 is transmitted to the sub-compressor 74. As the structure of the expander 72 and the sub compressor 74, for example, a reciprocating type, a rotary type, a scroll type, and the like are conceivable. The decompression path 22 includes the first decompression device 30, the expander 72, and the second decompression apparatus 31, and the main path includes the subordinate four-way valve 1, thereby reducing the decompression path 22 in both the cooling operation and the heating operation. The flow direction of the refrigerant passing through is made constant.
Moreover, in the figure, the solid line arrows indicate the flow direction of the refrigerant during the cooling operation, and the broken line arrows indicate the flow direction of the refrigerant during the heating operation. In the figure, each of the four-way valves 1 and 24 shows a state during cooling operation.

Hereinafter, the operation of the refrigerant circuit when the air-conditioning apparatus shown in Embodiment 8 performs the cooling operation and the heating operation will be described with reference to FIGS. 19 and 20.
FIG. 20 is a pressure-enthalpy diagram, where the solid line indicates the operation of the refrigerant circuit of the air conditioner shown in the eighth embodiment, and the alternate long and short dash line (the line connecting A-B-C-D-A). The operation | movement of the refrigerant circuit of the conventional air conditioner shown in FIG. Here, the case where the refrigerant is carbon dioxide is shown, and the high pressure side is in a supercritical state. A to F in the figure correspond to points A to F shown in FIGS. 19 and 29.

First, a case where the air conditioner performs a cooling operation will be described.
The operation of the conventional air conditioner is the same as the conventional operation shown in FIG. 6, and in FIG. 20, the inclination of the straight line from the point C to the point D is ignored.
On the other hand, in the air conditioner shown in the eighth embodiment, the solenoid valve 43 is driven, the discharge side connection port 44 and the first connection port 46 communicate, and the suction side connection port 45 and the second connection port 47. The main four-way valve 24 is switched so as to communicate with each other. Further, the first decompressor 30 and the second decompressor 31 are fully opened, and the expansion flow control valve 76 is closed.
When the compressor 23 is driven, the fourth pipe 7 of the subordinate four-way valve 1 communicating with the discharge side of the compressor 23 becomes high pressure, while the third pipe of the subordinate four-way valve 1 communicating with the suction side of the compressor 23 is increased. The pipe 6 has a low pressure. Therefore, the switching valve 12 moves to the first end cover 19 side from the operation of the dependent four-way valve 1 described above, and the state shown in FIG. 1 is established, and the first pipe 4 and the fourth pipe 7 are connected to the valve chamber 3. The second pipe 5 and the third pipe 6 communicate with each other via the return channel 11a.

  The high-pressure refrigerant vapor (point A) discharged from the compressor 23 proceeds to the outdoor heat exchanger 25 via the main four-way valve 24, and is cooled by the outdoor air in the outdoor heat exchanger 25, which is a radiator, to dissipate heat. Is done. The radiated refrigerant flows through the dependent four-way valve 1 (point B) and then flows into the expander 72 through the first pressure reducing device 30. In the expander 72, the refrigerant is expanded by isentropic change while giving the energy of the refrigerant to the rotational motion or amplitude motion of the expander 72. At this time, the rotational motion and the reciprocating motion of the expander 72 are transmitted to the sub compressor 74 via the expansion power transmission means 73, and the sub compressor 74 is driven. The refrigerant that has passed through the expander 72 passes through the second pressure reducing device 31 (point E), then proceeds to the indoor heat exchanger 26 via the dependent four-way valve 1, and is indoors in the indoor heat exchanger 26 that is an evaporator. Removes heat from the air and evaporates. The evaporated refrigerant vapor flows into the sub compressor 74 after passing through the main four-way valve 24 (D point). The refrigerant flowing into the sub-compressor 74 is compressed to the point F, and further compressed to the point A by the compressor 23 and discharged again.

When the air conditioner shown in Embodiment 8 is air-cooled, the expander 72 is provided. Therefore, the enthalpy difference (h3-h1) of the indoor heat exchanger 26 that is an evaporator is equal to the enthalpy difference ( larger than h3-h2). Therefore, the evaporation capacity, that is, the cooling capacity is increased as compared with the conventional example.
Further, since the refrigerant is compressed by the sub-compressor 74 using the expansion power obtained by the expander 72, the input of the compressor 23 is reduced, and the cooling operation obtained by dividing the evaporation capacity by the input of the compressor 23 is performed. The coefficient of performance increases compared to the conventional example.

Next, the heating operation will be described. The shape of the pressure-enthalpy diagram when the heating operation is performed is almost the same as FIG. However, when heating the conventional air conditioner shown in FIG. 29, the points B and C are interchanged.
The solenoid valve 43 is driven to switch the main four-way valve 24 so that the discharge side connection port 44 and the second connection port 47 communicate with each other and the suction side connection port 45 and the first connection port 46 communicate with each other. Further, the first decompressor 30 and the second decompressor 31 are fully opened, and the expansion flow control valve 76 is closed.
When the compressor 23 is driven, the third pipe 6 of the subordinate four-way valve 1 that communicates with the discharge side of the compressor 23 becomes high pressure, while the fourth pipe of the subordinate four-way valve 1 that communicates with the suction side of the compressor 23. The piping 7 becomes a low pressure. Therefore, the switching valve 12 moves to the second end cover 20 side from the operation of the subordinate four-way valve 1 described above, and the state shown in FIG. 2 is established. The second pipe 5 and the fourth pipe 7 communicate with each other via the folded flow path 11a.

  The high-pressure refrigerant vapor (point A) discharged from the compressor 23 proceeds to the indoor heat exchanger 26 via the main four-way valve 24 and is cooled by indoor air in the indoor heat exchanger 26 that is a radiator. The heat is dissipated. The radiated refrigerant flows through the dependent four-way valve 1 (point B) and then flows into the expander 72 through the first pressure reducing device 30. In the expander 72, the refrigerant is expanded by isentropic change while giving the energy of the refrigerant to the rotational motion or amplitude motion of the expander 72. At this time, the rotational motion and the reciprocating motion of the expander 72 are transmitted to the sub compressor 74 via the expansion power transmission means 73, and the sub compressor 74 is driven. The refrigerant that has passed through the expander 72 passes through the second decompression device 31 (point E). It progresses to the outdoor heat exchanger 25 via the subordinate four-way valve 1, and evaporates by taking heat from outside air in the outdoor heat exchanger 25 which is an evaporator. The evaporated refrigerant vapor flows into the sub compressor 74 after passing through the main four-way valve 24 (D point). The refrigerant flowing into the sub-compressor 74 is compressed to the point F, and further compressed to the point A by the compressor 23 and discharged again.

  When the air conditioner shown in Embodiment 8 is heated, the refrigerant is compressed by the sub compressor 74 using the expansion power obtained by the expander 72. Therefore, the input of the compressor 23 decreases, and the coefficient of performance at the time of heating operation obtained by dividing the heat radiation capacity by the input of the compressor 23 is increased as compared with the conventional example.

  As described above, since the subordinate four-way valve 1 used in the air conditioner of the eighth embodiment has the configuration shown in FIGS. 1 and 2, the subordinate four-way valve 1 is used for cooling as in the first embodiment. When the operation and the heating operation are performed, the switching of the dependent four-way valve 1 is automatically performed in response to the pressure difference between the third pipe 6 and the fourth pipe 7 without using an electromagnetic valve that controls only the dependent four-way valve 1. The valve 12 can be switched. As a result, it is possible to reduce the number of solenoid valves used in the air conditioner, the control unit for operating the solenoid valves, and the wiring, so that the air conditioner can be made compact, and the control is simplified and the cost is reduced. Can be realized.

  In addition, the air conditioner shown in the eighth embodiment includes the expander 72 in the decompression path 22 and the dependent four-way valve 1 connected to both ends of the decompression path 22, so that in either the cooling operation or the heating operation However, by switching the switching valve 12 of the subordinate four-way valve 1, the refrigerant passing through the expander 72 flows into the expander 72 from the inflow pipe 41 and is expanded while changing the isentropy, and obtains expansion power. A refrigerant flow in which the expander 72 functions can be formed. Therefore, the coefficient of performance can be increased in both the cooling operation and the heating operation of the air conditioner. Particularly in an air conditioner using carbon dioxide having a large pressure difference as a refrigerant, the effect of improving the coefficient of performance is large.

  Further, in both the cooling operation and the heating operation, the pressure in the valve chamber 3 of the subordinate four-way valve 1 becomes higher than the pressure in the return flow path 11a, and the valve body 11 is strongly pressed against the valve seat 21. However, there is no shortcut from the fourth pipe 7 to the second pipe 5 in the dependent four-way valve 1, and a refrigerant circuit for performing a desired operation can be formed.

In the eighth embodiment, the first decompression device 30 and the second decompression device 31 are fully opened and decompressed by the expander 72 in both the cooling operation and the heating operation. The air conditioner may be controlled by decompressing the refrigerant using the decompression device 30 or the second decompression device 31.
Further, in the eighth embodiment, the expansion flow control valve 76 is closed in both the cooling operation and the heating operation. However, when the operation of the expander 72 is not stable at the time of starting or the like, If sufficient control cannot be achieved by simply passing the refrigerant through the machine 72, the expansion flow control valve 76 may be adjusted so that the refrigerant flows through the expansion bypass pipe 75.
In the eighth embodiment, since the pressure reducing operation in the pressure reducing path 22 is mainly performed in the expander 72, either the first pressure reducing device 30 or the second pressure reducing device 31 may be deleted. Further, both may be deleted from the refrigerant circuit.

  In the present embodiment, the description of the reheat dehumidification operation is omitted, but the reheat dehumidification operation can be performed by making the configuration of the indoor heat exchanger 26 the same as in the first embodiment.

Further, the expander 72 and the sub compressor 74 may be configured in the same container, and the expander 72 and the sub compressor 27 may be configured integrally.
Further, the compressor 23 and the sub compressor 74 may be configured in the same container, and the compressor 23 and the sub compressor 74 may be configured integrally.
Further, the compressor 23, the sub compressor 74, and the expander 72 may all be put in the same container, and the compressor 23, the sub compressor 74, and the expander 72 may be configured integrally. Also good.
Further, the sub compressor 74 may be arranged on the discharge side of the compressor 23.
Further, the motor power of the compressor 23 may be reduced by connecting the expansion power transmission means 73 to the compressor 23 without using the sub-compressor 74.

Embodiment 9 FIG.
FIG. 21 is a refrigerant circuit diagram of an air conditioner according to Embodiment 9 of the present invention. In the air conditioner of the ninth embodiment, the decompression path 22 includes a gas-liquid separator 32 in addition to the configuration of the eighth embodiment. Further, an injection flow control valve 33 and an injection pipe 36 are provided.
The gas-liquid separator 32 is disposed downstream of the expander 72, and an injection pipe 36 connected to the gas-liquid separator 32 is configured to compress refrigerant vapor through the injection flow control valve 33 in the compression process of the compressor 32. It is connected to an injection port provided on the way.
Moreover, in the figure, the solid line arrows indicate the flow direction of the refrigerant during the cooling operation, and the broken line arrows indicate the flow direction of the refrigerant during the heating operation. In the figure, each of the four-way valves 1 and 24 shows a state during cooling operation.

Hereinafter, the operation of the refrigerant circuit when the air-conditioning apparatus shown in Embodiment 9 performs the cooling operation and the heating operation will be described with reference to FIGS. 21 and 22.
FIG. 22 is a pressure-enthalpy diagram, where the solid line indicates the operation of the refrigerant circuit of the air conditioner shown in the ninth embodiment, and the alternate long and short dash line (the line connecting A-B-C-D-A). The operation | movement of the refrigerant circuit of the conventional air conditioner shown in FIG. Here, the case where the refrigerant is carbon dioxide is shown, and the high pressure side is in a supercritical state. A to I and K in the figure correspond to points A to I and K shown in FIGS.

First, a case where the air conditioner performs a cooling operation will be described.
The operation of the conventional air conditioner is the same as the conventional operation shown in FIG. 6, and in FIG. 22, the inclination of the straight line from the C point to the D point is ignored.
On the other hand, in the air conditioner shown in the ninth embodiment, the solenoid valve 43 is driven, the discharge side connection port 44 and the first connection port 46 communicate with each other, and the suction side connection port 45 and the second connection port 47 are connected. The main four-way valve 24 is switched so as to communicate with each other. Further, the first pressure reducing device 30 is fully opened, and the expansion flow control valve 76 is closed.
When the compressor 23 is driven, the fourth pipe 7 of the subordinate four-way valve 1 communicating with the discharge side of the compressor 23 becomes high pressure, while the third pipe of the subordinate four-way valve 1 communicating with the suction side of the compressor 23 is increased. The pipe 6 has a low pressure. Therefore, the switching valve 12 moves to the first end cover 19 side from the operation of the dependent four-way valve 1 described above, and the state shown in FIG. 1 is established, and the first pipe 4 and the fourth pipe 7 are connected to the valve chamber 3. The second pipe 5 and the third pipe 6 communicate with each other via the return channel 11a.

  The high-pressure refrigerant vapor (point E) discharged from the compressor 23 proceeds to the outdoor heat exchanger 25 via the main four-way valve 24, and is cooled by the outdoor air in the outdoor heat exchanger 25, which is a radiator, to dissipate heat. Is done. The radiated refrigerant flows through the dependent four-way valve 1 (point B) and then flows into the expander 72 through the first pressure reducing device 30. In the expander 72, the refrigerant is expanded by isentropic change while giving the energy of the refrigerant to the rotational motion or amplitude motion of the expander 72. At this time, the rotational motion and the reciprocating motion of the expander 72 are transmitted to the sub compressor 74 via the expansion power transmission means 73, and the sub compressor 74 is driven. The refrigerant that has passed through the expander 72 flows into the gas-liquid separator 32 in a gas-liquid two-phase state, and is separated into refrigerant vapor (point K) and refrigerant liquid (point G). The separated refrigerant liquid (point G) is depressurized by the second decompression device 31 (point H), and then proceeds to the indoor heat exchanger 26 via the dependent four-way valve 1 to be an evaporator indoor heat exchanger. At 26, heat is taken from indoor air and evaporated. The evaporated refrigerant vapor flows into the sub compressor 74 after passing through the main four-way valve 24 (D point). The refrigerant that has flowed into the sub-compressor 74 is compressed to the point I, and further compressed to the point J by the compressor 23.

  On the other hand, the flow rate of the intermediate-pressure refrigerant vapor (point K) separated by the gas-liquid separator 32 is adjusted by the injection flow control valve 33 and passes through the injection pipe 36 in the middle of the compression process of the compressor 23 ( The refrigerant at point K is mixed with the refrigerant at point K and the refrigerant at point J (point L). Further, the refrigerant is compressed to point E and discharged again.

When the air conditioner shown in Embodiment 9 is air-cooled, the expander 72 and the gas-liquid separator 32 are provided. Therefore, the enthalpy difference (h3-h1) of the indoor heat exchanger 26 that is an evaporator is the conventional air. It becomes larger than the enthalpy difference (h3-h2) of the harmony machine. Therefore, the evaporation capacity, that is, the cooling capacity is increased as compared with the conventional example.
Further, the refrigerant is compressed by the sub compressor 74 using the expansion power obtained by the expander 72. Therefore, the input of the compressor 23 decreases, and the coefficient of performance during the cooling operation obtained by dividing the evaporation capacity by the input of the compressor 23 increases compared to the conventional example.
Further, since the injection pipe 36 is provided, the temperature (point E) when discharged from the compressor 23 is lower than that of the conventional example (point A), so that the reliability of the compressor 23 is improved.

Next, the heating operation will be described. The shape of the pressure-enthalpy diagram when the heating operation is performed is almost equal to that in FIG. However, when heating the conventional air conditioner shown in FIG. 29, the points B and C are interchanged.
The solenoid valve 43 is driven to switch the main four-way valve 24 so that the discharge side connection port 44 and the second connection port 47 communicate with each other and the suction side connection port 45 and the first connection port 46 communicate with each other. Further, the first pressure reducing device 30 is fully opened, and the expansion flow control valve 76 is closed.
When the compressor 23 is driven, the third pipe 6 of the subordinate four-way valve 1 that communicates with the discharge side of the compressor 23 becomes high pressure, while the fourth pipe of the subordinate four-way valve 1 that communicates with the suction side of the compressor 23. The piping 7 becomes a low pressure. Therefore, the switching valve 12 moves to the second end cover 20 side from the operation of the subordinate four-way valve 1 described above, and the state shown in FIG. 2 is established. The second pipe 5 and the fourth pipe 7 communicate with each other via the folded flow path 11a.

The high-pressure refrigerant vapor (point E) discharged from the compressor 23 proceeds to the indoor heat exchanger 26 via the main four-way valve 24, and is cooled by indoor air in the indoor heat exchanger 26 that is a radiator. The heat is dissipated. The radiated refrigerant flows into the expander 72 through the first pressure reducing device 30 after passing through the dependent four-way valve 1 (point B). In the expander 72, the refrigerant is expanded by isentropic change while giving the energy of the refrigerant to the rotational motion or amplitude motion of the expander 72. At this time, the rotational motion and the reciprocating motion of the expander 72 are transmitted to the sub compressor 74 via the expansion power transmission means 73, and the sub compressor 74 is driven. The refrigerant that has passed through the expander 72 flows into the gas-liquid separator 32 in a gas-liquid two-phase state, and is separated into refrigerant vapor (point K) and refrigerant liquid (point G). The separated refrigerant liquid (point G) is depressurized by the second decompression device 31 (point H), and then proceeds to the outdoor heat exchanger 25 via the dependent four-way valve 1 to be an evaporator outdoor heat exchanger. At 25, it takes heat from the outside air and evaporates. The evaporated refrigerant vapor flows into the sub compressor 74 after passing through the main four-way valve 24 (D point). The refrigerant flowing into the sub-compressor 74 is compressed to the point I and further compressed to the point J by the compressor 23.
The intermediate-pressure refrigerant vapor (point K) separated by the gas-liquid separator 32 is adjusted in flow rate by the injection flow control valve 33, passes through the injection pipe 36 and is in the middle of the compression process of the compressor 23 ( The refrigerant at point K) is mixed with the refrigerant at point K and the refrigerant at point J (point L). Further, the refrigerant is compressed to point E and discharged again.

When the air conditioner shown in Embodiment 9 is operated for heating, the refrigerant is compressed by the sub compressor 74 using the expansion power obtained by the expander 72. Therefore, the input of the compressor 23 decreases, and the coefficient of performance at the time of heating operation obtained by dividing the heat radiation capacity by the input of the compressor 23 is increased as compared with the conventional example.
Moreover, since it has the injection piping 36, the temperature (E point) when discharging from a compressor falls rather than a prior art example (A point). Therefore, the reliability of the compressor is improved.

  As described above, since the subordinate four-way valve 1 used in the air conditioner of the ninth embodiment has the configuration shown in FIGS. 1 and 2, the subordinate four-way valve 1 is used for cooling as in the first embodiment. When the operation and the heating operation are performed, the switching of the dependent four-way valve 1 is automatically performed in response to the pressure difference between the third pipe 6 and the fourth pipe 7 without using an electromagnetic valve that controls only the dependent four-way valve 1. The valve 12 can be switched. As a result, it is possible to reduce the number of solenoid valves used in the air conditioner, the control unit for operating the solenoid valves, and the wiring, so that the air conditioner can be made compact, and the control is simplified and the cost is reduced. Can be realized.

  Further, the air conditioner shown in the ninth embodiment includes the expander 72 and the gas-liquid separator 32 in the decompression path 22 and the subordinate four-way valve 1 connected to both ends of the decompression path 22, so that the cooling operation is performed. In both the heating operation and the switching valve 12 of the dependent four-way valve 1, the refrigerant passing through the expander 72 flows into the expander 72 from the inflow pipe 41 and is expanded while changing the isentropy. A refrigerant flow in which the expander 72 functions, such as obtaining expansion power, is formed, and the gas-liquid two-phase refrigerant that has passed through the expander 72 is separated into refrigerant vapor and refrigerant liquid in the gas-liquid separator 32. The refrigerant flow in which the gas-liquid separator 32 functions can be formed. Therefore, the coefficient of performance can be increased in both the cooling operation and the heating operation of the air conditioner. Particularly in an air conditioner using carbon dioxide having a large pressure difference as a refrigerant, the effect of improving the coefficient of performance is large. Further, the reliability of the compressor 23 is improved.

  Further, in both the cooling operation and the heating operation, the pressure in the valve chamber 3 of the subordinate four-way valve 1 becomes higher than the pressure in the return flow path 11a, and the valve body 11 is strongly pressed against the valve seat 21. However, there is no shortcut from the fourth pipe 7 to the second pipe 5 in the dependent four-way valve 1, and a refrigerant circuit for performing a desired operation can be formed.

In the ninth embodiment, the first decompression device 30 is fully opened and decompressed by the expander 72 in both the cooling operation and the heating operation. The air conditioner may be controlled by reducing the pressure.
Further, in the air conditioner of the ninth embodiment, the first pressure reducing device 30 may be deleted.
In the ninth embodiment, the expansion flow control valve 76 is closed in both the cooling operation and the heating operation. However, when the refrigeration cycle is not stable at the time of startup or the like, In cases where sufficient control cannot be achieved simply by passing the refrigerant, the expansion flow control valve 76 may be adjusted so that the refrigerant flows through the expansion bypass pipe 75.

  In the present embodiment, the description of the reheat dehumidification operation is omitted, but the reheat dehumidification operation can be performed by making the configuration of the indoor heat exchanger 26 the same as in the first embodiment.

Similarly to the eighth embodiment, the expander 72 and the subcompressor 74 may be configured in the same container, and the expander 72 and the subcompressor 27 may be configured integrally.
Further, the compressor 23 and the sub compressor 74 may be configured in the same container, and the compressor 23 and the sub compressor 74 may be configured integrally.
Further, the compressor 23, the sub compressor 74, and the expander 72 may all be put in the same container, and the compressor 23, the sub compressor 74, and the expander 72 may be configured integrally. Also good.
Further, the sub compressor 74 may be arranged on the discharge side of the compressor 23.
Further, the motor power of the compressor 23 may be reduced by connecting the expansion power transmission means 73 to the compressor 23 without using the sub-compressor 74.

  Further, the gas-liquid separator 32 may be provided upstream of the expander 72 instead of being provided downstream of the expander 72.

Embodiment 10 FIG.
FIG. 23 is a refrigerant circuit diagram of an air conditioner according to Embodiment 10 of the present invention. Unlike the first embodiment, the air conditioner of the tenth embodiment does not include the second decompression device 31, the gas-liquid separator 32, the injection pipe 36, and the injection flow control valve 33, and the decompression The path 22 includes only the first pressure reducing device 30. In addition, by providing the subordinate four-way valve 1, the flow direction of the refrigerant passing through the decompression path 22 is constant in both the cooling operation and the heating operation.
In the figure, the solid arrow indicates the refrigerant flow direction during the cooling operation, and the broken arrow indicates the refrigerant flow direction during the heating operation. In the figure, each of the four-way valves 1 and 24 shows a state during cooling operation.

Hereinafter, the operation when the air conditioner shown in Embodiment 10 performs the cooling operation and the heating operation will be described.
In the cooling operation, the main four-way valve is driven so that the discharge side connection port 44 and the first connection port 46 communicate with each other and the suction side connection port 45 and the second connection port 47 communicate with each other by driving the electromagnetic valve 43. 24 is switched.
When the compressor 23 is driven, the fourth pipe 7 of the dependent four-way valve 1 communicating with the discharge side of the compressor 23 is more than the third pipe 6 of the dependent four-way valve 1 communicating with the suction side of the compressor 23. Pressure increases. Therefore, the switching valve 12 moves to the first end cover 19 side from the operation of the dependent four-way valve 1 described above, and the state shown in FIG. 1 is established, and the first pipe 4 and the fourth pipe 7 are connected to the valve chamber 3. The second pipe 5 and the third pipe 6 communicate with each other via the return channel 11a.

  The high-pressure refrigerant vapor discharged from the compressor 23 proceeds to the outdoor heat exchanger 25 via the main four-way valve 24, and is cooled and condensed by the outdoor air in the outdoor heat exchanger 25 that is a condenser. The condensed refrigerant liquid is depressurized by the first pressure reducing device 30 after passing through the subordinate four-way valve 1, passes through the subordinate four-way valve 1, and then proceeds to the indoor heat exchanger 26 to exchange the indoor heat as an evaporator. The vessel 26 evaporates by taking heat from indoor air. The evaporated refrigerant vapor passes through the main four-way valve 24 and then proceeds to the compressor 23 where it is compressed and discharged again.

Further, in the heating operation, the solenoid valve 43 is driven so that the discharge side connection port 44 and the second connection port 47 communicate with each other, and the suction side connection port 45 and the first connection port 46 communicate with each other. The four-way valve 24 is switched.
When the compressor 23 is driven, the third pipe 6 of the dependent four-way valve 1 communicating with the discharge side of the compressor 23 is more than the fourth pipe 7 of the dependent four-way valve 1 communicating with the suction side of the compressor 23. Pressure increases. Therefore, the switching valve 12 moves to the first end cover 19 side from the operation of the subordinate four-way valve 1 described above and enters the state shown in FIG. 2, and the first pipe 4 and the third pipe 6 are connected to the valve chamber 3. The second pipe 5 and the fourth pipe 7 communicate with each other through the folded flow path 11a.

  The high-pressure refrigerant vapor discharged from the compressor 23 proceeds to the indoor heat exchanger 26 via the main four-way valve 24, and is cooled and condensed by indoor air in the indoor heat exchanger 26 that is a condenser. . The condensed refrigerant liquid is reduced in pressure by the first pressure reducing device 30 after passing through the subordinate four-way valve 1, and again passes through the subordinate four-way valve 1, and then proceeds to the outdoor heat exchanger 25, where outdoor heat as an evaporator is obtained. The exchanger 25 evaporates by taking heat from the outside air. The evaporated refrigerant vapor passes through the main four-way valve 24 and then proceeds to the compressor 23 where it is compressed and discharged again.

  As described above, since the subordinate four-way valve 1 used in the air conditioner of the tenth embodiment has the configuration shown in FIGS. 1 and 2, the subordinate four-way valve 1 is used for cooling as in the first embodiment. When the operation and the heating operation are performed, the switching of the dependent four-way valve 1 is automatically performed in response to the pressure difference between the third pipe 6 and the fourth pipe 7 without using an electromagnetic valve that controls only the dependent four-way valve 1. The valve 12 can be switched. As a result, it is possible to reduce the number of solenoid valves used in the air conditioner, the control unit for operating the solenoid valves, and the wiring, so that the air conditioner can be made compact, and the control is simplified and the cost is reduced. Can be realized.

In the conventional air conditioner, as shown in FIG. 29, the flow direction of the refrigerant passing through the first pressure reducing device 30 is reversed between the cooling operation and the heating operation. For this reason, the decompression device 30 has directivity with respect to the flow direction of the refrigerant, and the accuracy of the decompression amount and the flow rate control amount of the decompression device 30 is deteriorated depending on the flow direction of the refrigerant. When the resistance increases, the control performance of the decompression device 30 decreases and the lifetime of the device itself decreases.
On the other hand, since the air conditioner shown in the tenth embodiment includes the dependent four-way valve 1 connected to both ends of the pressure reducing path 22, the first pressure reducing device 30 is provided for both the cooling operation and the heating operation. The flow direction of the refrigerant passing therethrough can be made constant. Therefore, it is possible to satisfy the pressure reduction amount and the flow rate control amount of the first pressure reducing device 30, and it is possible to extend the structural life of the first pressure reducing device 30.

  Further, in both the cooling operation and the heating operation, the pressure in the valve chamber 3 of the subordinate four-way valve 1 becomes higher than the pressure in the return flow path 11a, and the valve body 11 is strongly pressed against the valve seat 21. However, there is no shortcut from the fourth pipe 7 to the second pipe 5 in the dependent four-way valve 1, and a refrigerant circuit for performing a desired operation can be formed.

  In the present embodiment, the description of the reheat dehumidification operation is omitted, but the reheat dehumidification operation can be performed by making the configuration of the indoor heat exchanger 26 the same as in the first embodiment.

Embodiment 11 FIG.
FIG. 24 is a refrigerant circuit diagram of an air conditioner according to Embodiment 11 of the present invention. The air conditioner of the eleventh embodiment is different from the tenth embodiment in the outdoor liquid pipe that connects the first pressure reducing device 30 to the outdoor heat exchanger 25 and the fourth pipe 7 of the subordinate four-way valve 1. 38. Further, the indoor heat exchanger 26 is disposed between the inflow pipe 41 and the outflow pipe 42, and one end of the indoor side gas pipe 39 is connected to the third pipe 6 of the subordinate four-way valve 1. In both the cooling operation and the heating operation, the flow direction of the refrigerant passing through the indoor heat exchanger 26 is made constant.
In the figure, the solid arrow indicates the refrigerant flow direction during the cooling operation, and the broken arrow indicates the refrigerant flow direction during the heating operation. In the figure, each of the four-way valves 1 and 24 shows a state during cooling operation.

Hereinafter, the operation in the case where the air conditioner shown in Embodiment 11 performs the cooling operation and the heating operation will be described.
In the cooling operation, the main four-way valve is driven so that the discharge side connection port 44 and the first connection port 46 communicate with each other and the suction side connection port 45 and the second connection port 47 communicate with each other by driving the electromagnetic valve 43. 24 is switched.
When the compressor 23 is driven, the fourth pipe 7 of the dependent four-way valve 1 communicating with the discharge side of the compressor 23 is more than the third pipe 6 of the dependent four-way valve 1 communicating with the suction side of the compressor 23. Pressure increases. Therefore, the switching valve 12 moves to the first end cover 19 side from the operation of the dependent four-way valve 1 described above, and the state shown in FIG. 1 is established, and the first pipe 4 and the fourth pipe 7 are connected to the valve chamber 3. The second pipe 5 and the third pipe 6 communicate with each other via the return channel 11a.

  The high-pressure refrigerant vapor discharged from the compressor 23 proceeds to the outdoor heat exchanger 25 via the main four-way valve 24, and is cooled and condensed by the outdoor air in the outdoor heat exchanger 25 that is a condenser. The condensed refrigerant liquid is depressurized by the first pressure reducing device 30, passes through the subordinate four-way valve 1, proceeds to the indoor heat exchanger 26, and heats the indoor air by the indoor heat exchanger 26 that is an evaporator. Take away and evaporate. The evaporated refrigerant vapor passes through the dependent four-way valve 1 and the main four-way valve 24 and then proceeds to the compressor 23 where it is compressed and discharged again.

Further, in the heating operation, the solenoid valve 43 is driven so that the discharge side connection port 44 and the second connection port 47 communicate with each other, and the suction side connection port 45 and the first connection port 46 communicate with each other. The four-way valve 24 is switched.
When the compressor 23 is driven, the third pipe 6 of the dependent four-way valve 1 communicating with the discharge side of the compressor 23 is more than the fourth pipe 7 of the dependent four-way valve 1 communicating with the suction side of the compressor 23. Pressure increases. Therefore, the switching valve 12 moves to the first end cover 19 side from the operation of the subordinate four-way valve 1 described above and enters the state shown in FIG. 2, and the first pipe 4 and the third pipe 6 are connected to the valve chamber 3. The second pipe 5 and the fourth pipe 7 communicate with each other through the folded flow path 11a.

  The high-pressure refrigerant vapor discharged from the compressor 23 proceeds to the indoor heat exchanger 26 via the main four-way valve 24 and the subordinate four-way valve 1, and is cooled by indoor air in the indoor heat exchanger 26 that is a condenser. And condensed. The condensed refrigerant liquid is reduced in pressure by the first pressure reducing device 30 after passing through the subordinate four-way valve 1, proceeds to the outdoor heat exchanger 25, and takes heat from the outside air in the outdoor heat exchanger 25 that is an evaporator. Evaporate. The evaporated refrigerant vapor passes through the main four-way valve 24 and then proceeds to the compressor 23 where it is compressed and discharged again.

  As described above, since the subordinate four-way valve 1 used in the air conditioner of the eleventh embodiment has the configuration shown in FIGS. 1 and 2, the subordinate four-way valve 1 is used for cooling as in the first embodiment. When the operation and the heating operation are performed, the switching of the dependent four-way valve 1 is automatically performed in response to the pressure difference between the third pipe 6 and the fourth pipe 7 without using an electromagnetic valve that controls only the dependent four-way valve 1. Since the valve 12 can be switched, the number of solenoid valves used in the air conditioner, the control unit for operating the solenoid valves, and the wiring can be reduced, the air conditioner can be made compact, and the control Simplification and cost reduction can be realized.

In the conventional air conditioner, as shown in FIG. 29, the flow direction of the refrigerant passing through the indoor heat exchanger 104 is reversed between the cooling operation and the heating operation. On the other hand, since the air conditioner shown in the eleventh embodiment includes the dependent four-way valve 1 connected to both ends of the indoor heat exchanger 26, the flow direction of the refrigerant passing through the indoor heat exchanger 26 is constant.
25 and 30 show the state of the end of a fin-and-tube heat exchanger 69 in which heat transfer tubes 68 are provided so as to be orthogonal to the fins 67 stacked in parallel as an example of the indoor heat exchanger. FIG. 25 shows the state of the indoor heat exchanger 26 in the air conditioner of Embodiment 11, and FIG. 30 shows the state of the indoor heat exchanger 104 in the conventional air conditioner. A solid line arrow and a broken line arrow shown in each figure indicate the flow direction of the refrigerant passing through the U-turn portion of the heat transfer tube 68. The solid line arrows indicate the flow direction of the refrigerant during the cooling operation, and the broken line arrows indicate the flow direction of the refrigerant during the heating operation.

A flow direction 66 of air passing between the stacked fins 67 is blown in a certain direction by a fan or the like. The refrigerant flows in from one heat transfer tube 68 located on the lower side of the heat exchanger, rises while making a U-turn at the end of the fin, turns back at the top, descends again while making a U-turn, and is located on the lower side. It flows out from the other heat transfer tube 68. At this time, in the case of the counter flow in which the refrigerant flows from the leeward heat transfer tube 68a to the windward heat transfer tube 68b, the heat exchanger is compared to the case of the parallel flow in which the refrigerant flows from the leeward heat transfer tube 68b to the leeward heat transfer tube 68a. The heat transfer performance of 69 increases.
In the conventional air conditioner, as shown in FIG. 30, the flow direction of the refrigerant passing through the indoor heat exchanger 104 is reversed between the cooling operation and the heating operation. It becomes a parallel flow, and the heat transfer performance of the heat exchanger decreases.
On the other hand, in the eleventh embodiment, since the dependent four-way valve 1 connected to both ends of the indoor heat exchanger 26 is provided, the flow direction of the refrigerant passing through the indoor heat exchanger 26 is constant in both the cooling operation and the heating operation. Therefore, as shown in FIG. 25, the flow of the refrigerant passing through the indoor heat exchanger 26 can be counterflowed in both the cooling operation and the heating operation. As a result, the heat transfer performance of the indoor heat exchanger 26 can be increased in both the cooling operation and the heating operation, and the cooling capacity and the heating capacity can be improved as compared with the conventional air conditioner.

  Further, in both the cooling operation and the heating operation, the pressure in the valve chamber 3 of the subordinate four-way valve 1 becomes higher than the pressure in the return flow path 11a, and the valve body 11 is strongly pressed against the valve seat 21. However, there is no shortcut from the fourth pipe 7 to the second pipe 5 in the dependent four-way valve 1, and a refrigerant circuit for performing a desired operation can be formed.

  In the present embodiment, the description of the reheat dehumidification operation is omitted, but the reheat dehumidification operation can be performed by making the configuration of the indoor heat exchanger 26 the same as in the first embodiment.

Embodiment 12 FIG.
FIG. 26 is a refrigerant circuit diagram of an air conditioner according to Embodiment 12 of the present invention. The air conditioner of the twelfth embodiment differs from the tenth embodiment in that an indoor side liquid pipe that connects the first decompressor 30 to the indoor heat exchanger 26 and the third pipe 6 of the subordinate four-way valve 1. 40. Further, the outdoor heat exchanger 25 is arranged between the inflow pipe 41 and the outflow pipe 42, one end of the outdoor gas pipe 37 is connected to the fourth pipe 7 of the subordinate four-way valve 1, and the subordinate four-way valve 1 In both the cooling operation and the heating operation, the flow direction of the refrigerant passing through the outdoor heat exchanger 25 is made constant.
Moreover, in the figure, the solid line arrows indicate the flow direction of the refrigerant during the cooling operation, and the broken line arrows indicate the flow direction of the refrigerant during the heating operation. In the figure, each of the four-way valves 1 and 24 shows a state during cooling operation.

Hereinafter, the operation when the air conditioner shown in Embodiment 12 performs the cooling operation and the heating operation will be described.
In the cooling operation, the main four-way valve is driven so that the discharge side connection port 44 and the first connection port 46 communicate with each other and the suction side connection port 45 and the second connection port 47 communicate with each other by driving the electromagnetic valve 43. 24 is switched.
When the compressor 23 is driven, the fourth pipe 7 of the dependent four-way valve 1 communicating with the discharge side of the compressor 23 is more than the third pipe 6 of the dependent four-way valve 1 communicating with the suction side of the compressor 23. Pressure increases. Therefore, the switching valve 12 moves to the first end cover 19 side from the operation of the dependent four-way valve 1 described above, and the state shown in FIG. 1 is established, and the first pipe 4 and the fourth pipe 7 are connected to the valve chamber 3. The second pipe 5 and the third pipe 6 communicate with each other via the return channel 11a.

  The high-pressure refrigerant vapor discharged from the compressor 23 proceeds to the outdoor heat exchanger 25 through the main four-way valve 24 and the subordinate four-way valve 1, and is cooled by the outside air in the outdoor heat exchanger 25 that is a condenser. Condensed. The condensed refrigerant liquid is reduced in pressure by the first pressure reducing device 30 after passing through the subordinate four-way valve 1, proceeds to the indoor heat exchanger 26, and heat is taken from indoor air by the indoor heat exchanger 26 that is an evaporator. Take away and evaporate. The evaporated refrigerant vapor passes through the main four-way valve 24 and then proceeds to the compressor 23 where it is compressed and discharged again.

Further, in the heating operation, the solenoid valve 43 is driven so that the discharge side connection port 44 and the second connection port 47 communicate with each other, and the suction side connection port 45 and the first connection port 46 communicate with each other. The four-way valve 24 is switched.
When the compressor 23 is driven, the third pipe 6 of the dependent four-way valve 1 communicating with the discharge side of the compressor 23 is more than the fourth pipe 7 of the dependent four-way valve 1 communicating with the suction side of the compressor 23. Pressure increases. Therefore, the switching valve 12 moves to the first end cover 19 side from the operation of the subordinate four-way valve 1 described above and enters the state shown in FIG. 2, and the first pipe 4 and the third pipe 6 are connected to the valve chamber 3. The second pipe 5 and the fourth pipe 7 communicate with each other through the folded flow path 11a.

  The high-pressure refrigerant vapor discharged from the compressor 23 proceeds to the indoor heat exchanger 26 via the main four-way valve 24, and is cooled and condensed by indoor air in the indoor heat exchanger 26 that is a condenser. . The condensed refrigerant liquid is depressurized by the first pressure reducing device 30, passes through the dependent four-way valve 1, proceeds to the outdoor heat exchanger 25, and takes heat from the outside air by the outdoor heat exchanger 25 that is an evaporator. Evaporate. The evaporated refrigerant vapor passes through the dependent four-way valve 1 and the main four-way valve 24 and then proceeds to the compressor 23 where it is compressed and discharged again.

  As described above, since the subordinate four-way valve 1 used in the air conditioner of the twelfth embodiment has the configuration shown in FIGS. 1 and 2, the subordinate four-way valve 1 is used for cooling as in the first embodiment. When the operation and the heating operation are performed, the switching of the dependent four-way valve 1 is automatically performed in response to the pressure difference between the third pipe 6 and the fourth pipe 7 without using an electromagnetic valve that controls only the dependent four-way valve 1. Since the valve 12 can be switched, the number of solenoid valves used in the air conditioner, the control unit for operating the solenoid valves, and the wiring can be reduced, the air conditioner can be made compact, and the control Simplification and cost reduction can be realized.

In the conventional air conditioner, as shown in FIG. 29, the flow direction of the refrigerant passing through the outdoor heat exchanger 102 is reversed between the cooling operation and the heating operation. Therefore, as described in the eleventh embodiment, as shown in FIG. 30, the refrigerant flow becomes a parallel flow in either one of the cooling operation and the heating operation, and the heat transfer performance of the heat exchanger decreases. .
On the other hand, in the twelfth embodiment, since the dependent four-way valve 1 connected to both ends of the outdoor heat exchanger 25 is provided, the flow direction of the refrigerant passing through the outdoor heat exchanger 25 is constant in both the cooling operation and the heating operation. Therefore, as shown in FIG. 25, the flow of the refrigerant passing through the outdoor heat exchanger 25 can be counterflowed in both the cooling operation and the heating operation. As a result, the heat transfer performance of the outdoor heat exchanger 25 can be increased in both the cooling operation and the heating operation, and the cooling capacity and the heating capacity can be improved as compared with the conventional air conditioner.

  Further, in both the cooling operation and the heating operation, the pressure in the valve chamber 3 of the subordinate four-way valve 1 becomes higher than the pressure in the return flow path 11a, and the valve body 11 is strongly pressed against the valve seat 21. However, there is no shortcut from the fourth pipe 7 to the second pipe 5 in the dependent four-way valve 1, and a refrigerant circuit for performing a desired operation can be formed.

  In the present embodiment, the description of the reheat dehumidifying operation is omitted, but the reheat dehumidifying operation can be performed by making the configuration of the outdoor heat exchanger 25 the same as in the first embodiment.

As described above, in the air conditioner shown in the first to twelfth embodiments, the first pipe 15 connected to the first cylinder chamber 13 of the subordinate four-way valve 1 is connected to the third pipe 6 and the second cylinder. Although the second conduit 16 connected to the chamber 14 is connected to the fourth pipe 7, even if the flow direction of the fluid flowing through the main path is switched by the main four-way valve 24, the switching valve 12 of the subordinate four-way valve 1 is If it is possible to operate so that the fluid always flows in the same direction in the refrigerant path connected at both ends to the subordinate four-way valve 1, the first conduit 15 and the second conduit 16 are connected to the third pipe 6 and It is not necessary to connect to the fourth pipe 7. That is, among the elements constituting the air conditioner, the first conduit 15 and the second conduit 16 are respectively connected to two points where the pressure of the fluid is different and the magnitude relationship of the pressure is reversed by switching by the main four-way valve 24. A part of the fluid flowing through the two points may be connected and the first conduit 15 and the second conduit 16 may be used to drive the valve body.
For example, if the main four-way valve 24 has a pair of conduits that are switched between high pressure and low pressure by the operation of the electromagnetic valve 43, the first conduit 15 is located at a position where one of the pair of conduits is connected. Alternatively, the second conduit 16 may be connected to the position where the other conduit is connected.
However, in this case, when the pressure difference between the valve chamber 3 and the return passage 11a is small and the force with which the valve body 11 is pressed against the valve seat 21 is small, the refrigerant flows between the fourth pipe 7 and the third pipe 6. Therefore, a sealed structure that prevents such a shortcut is necessary.

In the dependent four-way valve 1 shown in the first to twelfth embodiments, the pressure of the valve chamber 3 is made larger than the pressure of the folded flow path 11a to press the valve body 11 against the valve seat 21. The first pipe 4 has an inflow pipe 41, the second pipe 5 has an outflow pipe 42, the third pipe 6 has an indoor side liquid pipe 40 or an indoor side gas pipe 39, and the fourth pipe 7 has an outdoor side liquid pipe 38. However, if the subordinate four-way valve 1 does not need to press the valve body 11 against the valve seat 21, the combination of the four connecting portions connecting the subordinate four-way valve 1 and the refrigerant circuit is limited to the above combination. Absent.
For example, as shown in FIG. 27, the structure of the subordinate four-way valve 1 that does not require the valve body 11 to be pressed against the valve seat 21 does not include the piston shaft 10, and the valve body 11 includes the first piston 8 and the second piston 8. The switching valve 12 is formed by being joined to the piston 9, and the valve body 11 is in close contact with the valve seat 21 and the four-way valve main body 2, and the first pipe 4 to the third pipe 6 or the third pipe 6 are connected to the valve body 11. It is good also as a structure which provided the 1st communicating path 77 and the 2nd communicating path 78 which connect selectively from the 1 piping 4 to the 4th piping 7. FIG. By adopting such a configuration, the switching valve 12 is stably stabilized by the pressure difference between the first cylinder chamber 13 and the second cylinder chamber 14 as in the subordinate four-way valve shown in FIGS. 1 and 2. Slide in 2.

In addition, the outdoor heat exchanger 25 and the indoor heat exchanger 26 may be interchanged and connected, and the main four-way valve 24 and the subordinate are determined so as to determine the flow direction of the refrigerant in accordance with the refrigerant circuit after the exchange. The four-way valve 1 may be switched.
Moreover, although the heat exchanger provided in the refrigerant circuit is the outdoor heat exchanger 25 and the indoor heat exchanger 26, both may be any heat exchanger that can exchange heat between the refrigerant passing through the refrigerant circuit, and the structure thereof is arbitrary. It is.
Moreover, the medium in which the refrigerant exchanges heat is arbitrary, and air or water may be used.

  The throttle amount of the first decompressor 30 and the throttle amount of the second decompressor 31 are arbitrary, and each of the cooling operation and the heating operation of the air conditioner can be performed by using a decompressor having a variable valve opening. In operation, the optimum operation that maximizes the coefficient of performance is possible.

  The structure of the compressor 23 is arbitrary, and a refrigerant may be injected between the front stage and the rear stage as a two-stage compressor of the front stage and the rear stage.

  Moreover, as a refrigerant used for the air conditioner shown in each of the first to twelfth embodiments, chlorofluorocarbon, natural refrigerant such as carbon dioxide or hydrocarbon may be used. In particular, when carbon dioxide, which is a high-pressure refrigerant, is used in a conventional air conditioner, it becomes a supercritical refrigeration cycle with a large compressor work. By using the air conditioner shown in Embodiments 1 to 9, cooling operation is performed. And the coefficient of performance of the heating operation can be improved.

  In the first to seventh and ninth embodiments, as can be seen from the pressure-enthalpy diagram of each embodiment, the indoor heat exchanger 26 (at the time of cooling operation) or the outdoor heat exchanger 25 (at the time of heating operation) is used. The enthalpy of the refrigerant flowing in is smaller than that of the conventional example shown in FIG. 29, and the amount of refrigerant vapor is small. For this reason, the pressure loss of the indoor heat exchanger 26 (during cooling operation) or the outdoor heat exchanger 25 (during heating operation) decreases and the suction pressure of the compressor 23 increases, so that in either the cooling operation or the heating operation. Can also increase the coefficient of performance. Such an effect has been described in the second and fourth embodiments, but the same can be said in the other first, third, fifth, and seventh embodiments.

In each of the first to twelfth embodiments, one main four-way valve 24 for switching the flow direction of the main path, one main four-way valve 24 for switching the flow direction of the main path by using electric power of an electromagnetic valve or the like, and the outdoor heat exchanger 25, the refrigerant circuit in which one dependent four-way valve 1 is provided so that the direction of the refrigerant flowing into any one of the indoor heat exchangers 26 is a constant direction is shown. The number of valves 1 and the number of main four-way valves 24 are arbitrary. In that case, the valve body of the subordinate four-way valve is driven not by electric power but by the pressure change generated in the main path by switching by the main four-way valve, and the flow direction switched by the main four-way valve 24 is locally at a desired position. It is only necessary to determine the installation position of the subordinate four-way valve and the piping of the main path connected to the subordinate four-way valve so that the desired direction can be switched.
Further, the configuration of the refrigerant circuit is not limited to the refrigerant circuit of each of the embodiments.

  Further, although the refrigerant circuit using the four-way valve has been described, the switching means corresponding to the subordinate four-way valve 1 is not limited to the four-way valve, and the flow direction of the refrigerant can be switched without using an electromagnetic valve or the like. The number of flow paths to be switched is arbitrary as long as the switching means can form a refrigerant circuit so that the air conditioner can be operated. For example, as the switching means other than the four-way valve, as shown in FIG. 28, a three-way valve excluding the second pipe 5 of the dependent four-way valve 1 and the return flow path 11a of the valve body 11 shown in FIG.

  Moreover, although each said Embodiment 1-12 demonstrated with the air conditioner, it is not restricted to an air conditioner, The same structure is applicable in the refrigerating-cycle apparatus which heats and cools using a refrigerant | coolant.

Claims (12)

A main path formed by connecting a compressor, a first heat exchanger, a decompression path, and a second heat exchanger by a plurality of pipes, and at least three pipes of the main path installed in the main path A refrigeration cycle apparatus comprising switching means for switching the flow direction of the fluid flowing through the main path by moving the position of the valve body and switching the internal flow path, wherein the switching means And at least one main switching means for driving the valve body by using the pressure change generated in the main path by switching the flow direction of the main path by the main switching means. A refrigeration cycle apparatus comprising two subordinate switching means. The subordinate switching means has a pair of conduits connected to two points where the pressure of the fluid is different and the magnitude relation of the pressure is reversed by switching of the flow direction by the main switching means, and the two points are respectively connected using the conduits. The refrigeration cycle apparatus according to claim 1, wherein a part of the flowing fluid is taken in to drive the valve body. The subordinate switching means is a four-way valve, and a switching passage is formed between a pair of pistons that slide in an airtight manner in the main body of the subordinate switching means, a valve chamber provided between the pistons, and a valve seat surface in the valve chamber. A valve body that slides on the valve seat surface in conjunction with the piston, a pair of cylinder chambers provided on both sides of the valve chamber via the piston, a first pipe that is always in communication with the valve chamber, A second pipe that opens to the valve seat surface and is always in communication with the switching passage, opens to the valve seat surface, and has either one of the valve chamber or the switching passage in a mutually contradictory relationship due to the switching movement of the valve body. 3. The refrigeration cycle apparatus according to claim 2, further comprising a third pipe and a fourth pipe communicating with each other, and a pair of conduits respectively connected to the pair of cylinder chambers. 4. The refrigeration cycle apparatus according to claim 3, wherein one of the pair of conduits is connected to a third pipe of the subordinate switching unit, and the other is connected to a fourth pipe of the subordinate switching unit. The main switching means is arranged so that the refrigerant discharged from the compressor can be selectively flowed to the first heat exchanger or the second heat exchanger, and the subordinate switching means is connected to the first pipe and the first heat exchanger. 2 pipes are connected to both ends of the decompression path, and either one of the third pipe and the fourth pipe is connected to the first heat exchanger, and the other is connected to the second heat exchanger. The refrigeration cycle apparatus according to claim 3 or 4, wherein the refrigeration cycle apparatus is provided. The refrigeration cycle apparatus according to claim 5, wherein the decompression path includes at least one of a decompression device, a gas-liquid separator, a supercooling heat exchanger, an ejector, and an expander. The main switching means is arranged so that the refrigerant discharged from the compressor can be selectively flowed to the first heat exchanger or the second heat exchanger, and the subordinate switching means is connected to the first pipe and the first heat exchanger. 2 pipes are connected to both ends of the first heat exchanger, one of the third pipe and the fourth pipe is connected to the main switching means, and the other is connected to the decompression path. The refrigeration cycle apparatus according to claim 3 or 4, wherein: The main switching means is arranged so that the refrigerant discharged from the compressor can be selectively flowed to the first heat exchanger or the second heat exchanger, and the subordinate switching means is connected to the first pipe and the first heat exchanger. 2 pipes are connected to both ends of the second heat exchanger, one of the third pipe and the fourth pipe is connected to the main switching means, and the other is connected to the decompression path. The refrigeration cycle apparatus according to claim 3 or 4, wherein: The second heat exchanger includes a pre-stage heat exchanger, a post-stage heat exchanger, and a reheat dehumidification decompression device provided between the pre-stage heat exchanger and the post-stage heat exchanger. The refrigeration cycle apparatus according to any one of claims 1 to 8. The refrigeration cycle apparatus according to any one of claims 1 to 9, wherein the compressor is a two-stage compressor. The refrigeration cycle apparatus according to any one of claims 1 to 10, wherein the fluid flowing through the main path is carbon dioxide, which is a natural refrigerant. A switching passage is formed between a pair of pistons that slide in an airtight manner in the main body, a valve chamber provided between the pistons, and a valve seat surface in the valve chamber, and the valve seat surface in conjunction with the piston A valve body that slides through the piston, a pair of cylinder chambers provided on both sides of the valve chamber via the piston, a first pipe that is always in communication with the valve chamber, an opening in the valve seat surface, and the switching passage A second pipe that is always in communication, a third pipe that opens to the valve seat surface and communicates with either the valve chamber or the switching passage in a mutually contradictory relationship by the switching movement of the valve body; A four-way valve comprising a pipe and a pair of conduits respectively connected to the pair of cylinder chambers, one connected to the third pipe and the other connected to the fourth pipe, The magnitude of the pressure of the fluid flowing through each of the fourth pipes Four-way valve and drives the valve body by the change.

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