JP2011112327A - Air conditioner and refrigerating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner with high efficiency by reducing pressure loss of an outdoor heat exchanger, an indoor heat exchanger and a connection pipe even when using a refrigerant with a small refrigeration capability per unit volume compared with a refrigerant R410A. <P>SOLUTION: The air conditioner is characterized by using a refrigerant with a small refrigeration capability per unit volume compared with a refrigerant R410A as a refrigerant to be sealed in a refrigerant circuit, separating a gas refrigerant and a liquid refrigerant from a refrigerant which is gas-liquid two phase coming out of a first indoor heat exchanger by an indoor gas-liquid separator, and the liquid refrigerant only is made to flow into a second indoor heat exchanger. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a cooling / heating apparatus and a refrigeration apparatus using a refrigerant.

  After ozone layer destruction due to the use of CFCs has become a problem, HCFC is used as an alternative refrigerant, and HFC (R410A) is now widely used (Patent Document 1).

JP 2008-111161 A

  However, the global warming potential (GWP) of the R410A refrigerant is as large as 2088, which is a problem from the viewpoint of preventing global warming.

  From the viewpoint of preventing global warming, for example, HFO1234yf of GWP4 has been proposed as a refrigerant having a small GWP, but this refrigerant is a refrigerant having a small refrigerating capacity per unit volume compared to the R410A refrigerant.

  Therefore, if this refrigerant is applied as it is in the conventional apparatus to obtain the same capacity as the R410A refrigerant, it is necessary to increase the rotational speed of the compressor and increase the volume circulation amount of the refrigerant. When the rotation speed of the compressor is increased until the same capacity is obtained, the pressure loss of the pipe including the heat exchanger becomes large, resulting in a decrease in performance.

  Therefore, the present invention reduces the pressure loss of the outdoor heat exchanger, the indoor heat exchanger (evaporator, condenser), and the connecting pipe, even when a refrigerant having a smaller refrigeration capacity per unit volume than the R410A refrigerant is used. An object of the present invention is to provide a highly efficient refrigeration apparatus and air conditioning apparatus that are reduced.

  In order to solve the above-mentioned problems, the present invention provides a compressor, a four-way valve, an outdoor heat exchanger, a throttle device, a liquid connection pipe, a first indoor heat exchanger, and a reheat dehumidifying throttle device. , The indoor side gas-liquid separator, the second indoor heat exchanger, and the gas connection pipe are sequentially connected by a connection pipe to form an annular refrigerant circuit, and during cooling operation, the refrigerant is the compressor, the four-way valve, the Outdoor heat exchanger, the expansion device, the liquid connection pipe, the first indoor heat exchanger, the reheat dehumidification expansion device, the indoor side gas-liquid separator, the second indoor heat exchanger, the gas The outlet of the reheat dehumidifying throttling device is connected to the indoor side gas-liquid separator, and the liquid outlet pipe of the indoor side gas-liquid separator and the second indoor side heat exchanger are connected. The gas outlet pipe of the indoor gas-liquid separator is connected to the outlet of the second indoor heat exchanger via an indoor check valve. A connected air conditioner and, as a refrigerant sealed in the refrigerant circuit, characterized in that the refrigerating capacity per unit volume as compared with R410A refrigerant with little refrigerant.

Further, the present invention according to claim 2 is the air conditioning apparatus according to the present invention, wherein an outdoor gas-liquid separator is provided between the expansion device and the liquid connection pipe, and the outlet of the expansion device is the air outlet during cooling operation. Connected to the outdoor gas-liquid separator, the liquid outlet pipe of the outdoor gas-liquid separator and the liquid connection pipe are connected, and the gas outlet pipe of the outdoor gas-liquid separator is connected to the four-way valve via a two-way valve. And a cooling / heating device connected to a low-pressure side pipe between the compressor and the refrigerant enclosed in the refrigerant circuit as R
A refrigerant having a small refrigerating capacity per unit volume as compared with the 410A refrigerant is used.

  The present invention according to claim 3 includes a compressor, a four-way valve, a first outdoor heat exchanger, a second outdoor gas-liquid separator, a second outdoor heat exchanger, a throttling device, a liquid connection pipe, An indoor heat exchanger, gas connection pipes are sequentially connected by a connection pipe to form an annular refrigerant circuit, and during heating operation, the refrigerant is the compressor, the four-way valve, the gas connection pipe, the indoor heat exchanger, The liquid connection pipe, the expansion device, the second outdoor heat exchanger, the second outdoor gas-liquid separator, and the first outdoor heat exchanger flow in this order, and the second outdoor heat exchanger The outlet is connected to the second outdoor gas-liquid separator, the liquid outlet pipe of the second outdoor gas-liquid separator is connected to the inlet of the first outdoor heat exchanger, and the second A gas outlet pipe of the outdoor gas-liquid separator is an air conditioner connected to the outlet of the first outdoor heat exchanger via an outdoor check valve. As refrigerant sealed in the refrigerant circuit, characterized in that the refrigerating capacity per unit volume as compared with R410A refrigerant with little refrigerant.

  Furthermore, the present invention according to claim 4 is a compressor, a four-way valve, a first outdoor heat exchanger, a second outdoor gas-liquid separator, a second outdoor heat exchanger, a throttling device, and a first outdoor side. A gas-liquid separator, a liquid connection pipe, and a first indoor heat exchanger, a reheat dehumidifying expansion device, an indoor side gas-liquid separator, a second indoor heat exchanger, and a gas connection pipe are sequentially connected by the connection pipe. In the cooling operation, the refrigerant is the compressor, the four-way valve, the first outdoor heat exchanger, the second outdoor gas-liquid separator, and the second outdoor heat. Exchanger, throttle device, outdoor gas-liquid separator, liquid connection pipe, first indoor heat exchanger, reheat dehumidifying throttle device, indoor gas-liquid separator, second indoor The heat exchanger and the gas connection pipe flow in this order, the outlet of the expansion device is connected to the outdoor gas-liquid separator, and the liquid outlet arrangement of the outdoor gas-liquid separator And the liquid connection pipe is connected, and the gas outlet pipe of the outdoor gas-liquid separator is connected to a low-pressure side pipe between the four-way valve and the compressor via a two-way valve, and the reheat dehumidifying throttling device Is connected to the indoor gas-liquid separator, the liquid outlet pipe of the indoor gas-liquid separator is connected to the second indoor heat exchanger, and the gas outlet pipe of the indoor gas-liquid separator is It is connected to the outlet of the second indoor heat exchanger via an indoor check valve, and during heating operation, the refrigerant is the compressor, the four-way valve, the gas connection pipe, the second indoor heat exchanger, The indoor-side gas-liquid separator, the reheat dehumidifying throttling device, the first indoor heat exchanger, the liquid connecting pipe, the outdoor-side gas-liquid separator, the throttling device, and the second outdoor heat exchanger The second outdoor gas-liquid separator flows in the order of the first outdoor heat exchanger, and the first outdoor heat exchanger The mouth is connected to the second outdoor gas-liquid separator, the outlet pipe of the second outdoor gas-liquid separator and the inlet of the second outdoor heat exchanger are connected, and the second outdoor side A gas outlet pipe of the gas-liquid separator is an air conditioning apparatus connected to the inlet of the first outdoor heat exchanger via an outdoor check valve, and is used as a refrigerant sealed in the refrigerant circuit as compared with the R410A refrigerant. Thus, a refrigerant having a small refrigeration capacity per unit volume is used.

  The refrigeration apparatus of the present invention according to claim 5 comprises an annular refrigerant circuit by sequentially connecting a compressor, a condenser, a first throttle device, a first evaporator, a gas-liquid separator, and a second evaporator. The refrigerant flows in the order of the compressor, the condenser, the first throttling device, the first evaporator, the gas-liquid separator, and the second evaporator, and the outlet of the first evaporator is the gas-liquid separation. A gas outlet line of the gas-liquid separator and the second evaporator are connected, and a gas outlet pipe of the gas-liquid separator is connected to the outlet of the second evaporator via a check valve. In addition, a refrigerant having a smaller refrigeration capacity per unit volume than the R410A refrigerant is used as the refrigerant sealed in the refrigerant circuit.

In the refrigeration apparatus of the present invention according to claim 6, an annular refrigerant circuit is configured by sequentially connecting the compressor, the first condenser, the second gas-liquid separator, the second condenser, the expansion device, and the evaporator. The refrigerant flows in the order of the compressor, the first condenser, the second gas-liquid separator, the second condenser, the expansion device, and the evaporator, and the outlet of the first condenser is the second Connected to a gas-liquid separator, a gas outlet pipe of the second gas-liquid separator and an inlet of the second condenser are connected, and the liquid outlet pipe of the second gas-liquid separator is connected to the gas outlet pipe via a check valve. In addition to being configured to be connected to the outlet of the second condenser, a refrigerant having a small refrigerating capacity per unit volume as compared with the R410A refrigerant is used as the refrigerant sealed in the refrigerant circuit.

  Further, in the present invention according to claim 7, in each of the above inventions, as the refrigerant, the hydrofluoroolefin is based on tetrafluoropropene or trifluoropropene, and difluoromethane, pentafluoroethane or tetrafluoroethane is used as a global warming. It is characterized in that a refrigerant in which two components or three components are mixed is used so that the coefficient is 5 or more and 750 or less, preferably 350 or less, and more preferably 150 or less.

  Further, according to the present invention of claim 8, in each of the above inventions, as the refrigerating machine oil used in the compressor, polyoxyalkylene glycols, polyvinyl ethers, poly (oxy) alkylene glycol or a monoether thereof and polyvinyl ether A synthetic oil mainly containing an oxygen-containing compound of any of polymers, polyol esters and polycarbonates, or a synthetic oil mainly containing alkylbenzenes and α-olefins is used.

  According to the present invention, even when a refrigerant having a smaller refrigeration capacity per unit volume than that of the R410A refrigerant is used, the efficiency of the air conditioner can be improved by reducing the pressure loss of the refrigerant circuit.

The block diagram of the air-conditioning apparatus by Embodiment 1 of this invention The figure which shows the comparison of the refrigerating capacity per unit volume of R410A refrigerant | coolant and HFO1234yf refrigerant | coolant. The figure which shows the flow velocity in piping of R410A refrigerant | coolant and HFO1234yf refrigerant | coolant. The figure which shows the flow of the refrigerant in the cooling operation Diagram showing refrigerant flow in heating operation Diagram showing refrigerant flow in reheat dehumidification operation The figure which shows the relationship between the mixing ratio of HFO1234yf, and refrigerating capacity ratio

  The air-conditioning apparatus according to the first embodiment of the present invention is a refrigerant in which an indoor-side gas-liquid separator is provided between a reheat dehumidifying expansion device for an indoor unit and a second indoor heat exchanger and sealed in a refrigerant circuit. As described above, a refrigerant having a small refrigerating capacity per unit volume as compared with the R410A refrigerant is used. According to the present embodiment, during the cooling operation, the gas-liquid two-phase refrigerant that has exited the first indoor heat exchanger is separated into the gas refrigerant and the liquid refrigerant by the indoor side gas-liquid separator, and only the liquid refrigerant is used. Since the refrigerant flows through the second indoor heat exchanger, the refrigerant speed can be suppressed and the pressure loss of the second indoor heat exchanger can be reduced.

  According to a second embodiment of the present invention, in the air-conditioning apparatus according to the first embodiment, an outdoor gas-liquid separator is provided between the expansion device of the outdoor unit and the liquid connection pipe connecting the outdoor unit and the indoor unit. As the refrigerant to be enclosed in the refrigerant circuit, a refrigerant having a small refrigerating capacity per unit volume as compared with the R410A refrigerant is used. According to the present embodiment, during the cooling operation, the gas-liquid two-phase refrigerant exiting the expansion device is separated into the gas refrigerant and the liquid refrigerant in the outdoor gas-liquid separator, and only the liquid refrigerant flows into the indoor unit. The pressure loss of the indoor unit and the gas connection pipe can be reduced by suppressing the refrigerant speed.

In the third embodiment of the present invention, the second outdoor heat exchanger and the second outdoor heat exchanger are arranged between the second outdoor heat exchanger and the second outdoor heat exchanger.
A refrigerant having a small refrigeration capacity per unit volume as compared with the R410A refrigerant is used as the refrigerant enclosed in the refrigerant circuit and sealed in the refrigerant circuit. According to the present embodiment, during the heating operation, the gas-liquid two-phase refrigerant that has exited the second outdoor heat exchanger is separated into the gas refrigerant and the liquid refrigerant by the second outdoor-side gas-liquid separator, Since only the refrigerant flows to the first outdoor heat exchanger, the refrigerant speed can be suppressed and the pressure loss of the first outdoor heat exchanger can be reduced.

  In the fourth embodiment of the present invention, an indoor side gas-liquid separator is provided between the reheat dehumidifying expansion device for the indoor unit and the second indoor heat exchanger, and the expansion device for the outdoor unit and the liquid connection pipe are provided. An outdoor gas-liquid separator is provided between the first outdoor heat exchanger and the second outdoor heat exchanger, and a second outdoor gas-liquid separator is provided between the first outdoor heat exchanger and the refrigerant circuit. , A refrigerant having a smaller refrigeration capacity per unit volume than the R410A refrigerant is used. According to the present embodiment, during the cooling operation, the gas-liquid two-phase refrigerant exiting the expansion device is separated into the gas refrigerant and the liquid refrigerant in the outdoor gas-liquid separator, and only the liquid refrigerant flows into the indoor unit. The refrigerant speed is suppressed, pressure loss of the indoor unit and the gas connection pipe is reduced, and the gas-liquid two-phase refrigerant exiting the first indoor heat exchanger is converted into gas refrigerant and liquid refrigerant by the indoor side gas-liquid separator. Since the liquid refrigerant is separated and flows only to the second indoor heat exchanger, the refrigerant speed can be suppressed and the pressure loss of the second indoor heat exchanger can be reduced. Further, during the heating operation, the gas-liquid two-phase refrigerant that has exited the second outdoor heat exchanger is separated into gas refrigerant and liquid refrigerant by the second outdoor-side gas-liquid separator, and only the liquid refrigerant is in the first outdoor unit. Since it flows to the heat exchanger, the refrigerant speed can be suppressed and the pressure loss of the second outdoor heat exchanger can be reduced.

  In the refrigeration apparatus according to claim 5 of the present invention, a compressor, a condenser, a first throttle device, a first evaporator, a gas-liquid separator, and a second evaporator are sequentially connected to form an annular refrigerant circuit, The refrigerant flows in the order of the compressor, the condenser, the first expansion device, the first evaporator, the gas-liquid separator, and the second evaporator, and the outlet of the first evaporator is the gas-liquid separator. The gas outlet pipe of the gas-liquid separator and the second evaporator are connected, and the gas outlet pipe of the gas-liquid separator is connected to the outlet of the second evaporator via a check valve. In addition to the configuration, a refrigerant having a small refrigerating capacity per unit volume compared to the R410A refrigerant is used as the refrigerant sealed in the refrigerant circuit.

  According to a sixth aspect of the present invention, a compressor, a first condenser, a second gas-liquid separator, a second condenser, a throttling device, and an evaporator are sequentially connected to form an annular refrigerant circuit. The compressor, the first condenser, the second gas-liquid separator, the second condenser, the throttling device, and the evaporator flow in this order, and the outlet of the first condenser is the second gas-liquid separator. And a gas outlet pipe of the second gas-liquid separator and an inlet of the second condenser are connected, and the liquid outlet pipe of the second gas-liquid separator is connected to the second condenser via a check valve. And a refrigerant having a smaller refrigeration capacity per unit volume than the R410A refrigerant is used as the refrigerant sealed in the refrigerant circuit.

  And the seventh embodiment of the present invention is the first to sixth embodiments, wherein the hydrofluoroolefin is based on tetrafluoropropene or trifluoropropene as the refrigerant, and difluoromethane or pentafluoroethane or Tetrafluoroethane is a refrigerant mixed with two or three components so that the global warming potential is 5 or more and 750 or less, preferably 350 or less, and more preferably 150 or less. . According to the present embodiment, by using a refrigerant having a small global warming coefficient, even if a refrigerant that is not recovered is released into the atmosphere, the influence on global warming can be kept to a minimum.

In an eighth embodiment of the present invention, polyoxyalkylene glycols, polyvinyl ethers, poly (oxy) alkylene glycols or monoethers thereof are used as the refrigerating machine oil used in the compressor in the first to seventh embodiments. And a synthetic oil mainly containing an oxygen-containing compound of any one of a copolymer of poly (vinyl ether), polyol ester and polycarbonate, or a synthetic oil mainly containing alkylbenzenes and α-olefins. According to the present embodiment, when trying to obtain the same capacity as R410A, the sliding loss can be reduced and the efficiency of the compressor can be prevented from being lowered. Therefore, the pressure loss at the portion through which the gaseous refrigerant passes. Can be reduced.

  In the following, an embodiment of the present invention will be described by taking an air conditioning apparatus as an example. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a configuration diagram of an air-conditioning apparatus according to the present embodiment.

  The air-conditioning apparatus according to the present embodiment includes a compressor 1 that compresses refrigerant, a four-way valve 2 that switches a refrigerant circuit during cooling and heating operation, a first outdoor heat exchanger 3 that exchanges heat between the refrigerant and outside air, and a second outdoor During the heating operation of the heat exchanger 4, the gas-liquid two-phase refrigerant that has exited the second outdoor heat exchanger 4 is separated into a gas refrigerant and a liquid refrigerant, and only the liquid refrigerant flows into the first outdoor heat exchanger 3. 2 outdoor gas-liquid separator 5, throttle device 6 for decompressing the refrigerant, and gas-liquid two-phase refrigerant exiting the throttle device 6 during the cooling operation is separated into a gas refrigerant and a liquid refrigerant, and only the liquid refrigerant is the first. The outdoor gas-liquid separator 7 that flows to the indoor heat exchanger 8, the first indoor heat exchanger 8 that exchanges heat between the refrigerant and the indoor air, the second indoor heat exchanger 9, and the first room during the cooling operation The gas-liquid two-phase refrigerant exiting the heat exchanger 8 is separated into a gas refrigerant and a liquid refrigerant, and only the liquid refrigerant flows into the second indoor heat exchanger 9. The regenerator 10 is configured with a reheat dehumidifying expansion device 11 that depressurizes the liquid refrigerant that has exited the first indoor heat exchanger 8 by increasing the throttle opening during air conditioning operation and decreasing the throttle opening during dehumidifying operation. .

  A compressor 1, a four-way valve 2, a first outdoor heat exchanger 3, a second outdoor gas-liquid separator 5, a second outdoor heat exchanger 4, a throttling device 6, an outdoor gas-liquid separator 7, and The first indoor heat exchanger 8, the reheat dehumidifying expansion device 11, the indoor side gas-liquid separator 10, and the second indoor heat exchanger 9 are sequentially connected in a ring shape with a connecting pipe.

  A gas outlet pipe 12 of the outdoor gas-liquid separator 7 is connected to a low-pressure side pipe between the four-way valve 2 and the compressor 1 via a two-way valve 13 to constitute a first outdoor bypass circuit 14. The liquid outlet pipe 15 of the liquid separator 7 is connected to the liquid connection pipe 26, and the gas outlet pipe 16 of the indoor gas-liquid separator 10 is connected to the outlet of the second indoor heat exchanger 9 via the indoor check valve 17. Are connected to each other to form an indoor bypass circuit 18, a liquid outlet pipe 19 of the indoor gas-liquid separator 10 is connected to the second indoor heat exchanger 9, and the gas of the second outdoor gas-liquid separator 5 is connected. The outlet pipe 20 is connected to the outlet of the first outdoor heat exchanger 3 via the outdoor check valve 21 to constitute a second outdoor bypass circuit 23, and the liquid in the second outdoor gas-liquid separator 5. The outlet pipe 22 and the first outdoor heat exchanger 3 are connected.

  The outdoor unit 24 and the indoor unit 25 are connected by a liquid connection pipe 26 and a gas connection pipe 27.

  During the cooling operation, the refrigerant compressed by the compressor 1 becomes a high-temperature and high-pressure refrigerant and is sent to the first outdoor heat exchanger 3 and the second outdoor heat exchanger 4 through the four-way valve 2. Then, heat is exchanged with the outside air to dissipate the heat, and the high-pressure liquid refrigerant is sent to the expansion device 6. In the expansion device 6, the pressure is reduced to form a low-temperature and low-pressure two-phase refrigerant, which is sent to the indoor unit 25 through the liquid connection pipe 26. At this time, the reheat dehumidifying squeezing device 11 is in an open state, and is not depressurized when the refrigerant flows through the reheat dehumidifying squeezing device 11, and the first indoor heat exchanger 8 and the second indoor heat exchanger are not depressurized. 9 enters into heat exchange with room air, absorbs heat, evaporates and becomes a low-temperature gas refrigerant. At this time, the room air is cooled to cool the room. Further, the refrigerant passes through the gas connection pipe 27 and returns to the compressor 1 through the four-way valve 2.

  During the heating operation, the refrigerant compressed by the compressor 1 becomes a high-temperature and high-pressure refrigerant, passes through the four-way valve 2 and the gas connection pipe 27, and is sent to the indoor unit 25. At this time, the reheat dehumidifying squeezing device 11 is in an open state and is not depressurized when the refrigerant flows through the reheat dehumidifying squeezing device 11, and the high-temperature and high-pressure refrigerant is supplied to the second indoor heat exchanger 9, Enters the indoor heat exchanger 8 and exchanges heat with the indoor air to dissipate the heat and cool to become a high-pressure liquid refrigerant. At this time, the room air is heated to heat the room. Thereafter, the refrigerant is sent to the expansion device 6 through the liquid connection pipe 26 and is decompressed in the expansion device 6 to become a low-temperature and low-pressure two-phase refrigerant, and the second outdoor heat exchanger 4 and the first outdoor heat exchanger 3. To evaporate by exchanging heat with the outside air and returned to the compressor 1 via the four-way valve 2.

  During the reheat dehumidifying operation, the refrigerant compressed by the compressor 1 becomes a high-temperature and high-pressure refrigerant and is sent to the first outdoor heat exchanger 3 and the second outdoor heat exchanger 4 through the four-way valve 2. However, the rotational speed of the blower is lowered, and the amount of heat dissipated by exchanging heat with the outside air is controlled. Then, it becomes a high-pressure gas-liquid two-phase refrigerant and is sent to the expansion device 6. At this time, the expansion device 6 is controlled to be fully open, is not decompressed, remains in a high-pressure two-phase refrigerant, is sent to the indoor unit 25 through the liquid connection pipe 26, and is radiated by the first indoor heat exchanger 8. High pressure and low temperature liquid refrigerant. At this time, since the opening degree of the reheat dehumidifying expansion device 11 is controlled to be small, the reheat dehumidifying expansion device 11 is depressurized when the refrigerant flows to become a low-pressure and low-temperature refrigerant, and is supplied to the second indoor heat exchanger 9. It exchanges heat with the incoming room air to absorb heat, evaporates and becomes a low-temperature gas refrigerant. At this time, the indoor air is cooled and dehumidified by the second indoor heat exchanger 9, and then heated by the first indoor heat exchanger 8, so it is dehumidified without lowering the indoor temperature. The low-temperature gas refrigerant is returned to the compressor 1 through the gas connection pipe 27 and the four-way valve 2.

  In this way, air conditioning and dehumidifying operations are performed.

  In the refrigerant circuit constituting the air conditioning apparatus according to the present embodiment, a refrigerant having a small refrigerating capacity per unit volume compared to the R410A refrigerant is enclosed. In this refrigerant, the hydrofluoroolefin is based on tetrafluoropropene or trifluoropropene, and difluoromethane, pentafluoroethane, or tetrafluoroethane is preferably 350 or less so that the global warming potential is 5 or more and 750 or less. Hereinafter, it is a mixture of two components or three components so as to be more preferably 150 or less.

  The refrigerating machine oil used for the compressor 1 is any one of polyoxyalkylene glycols, polyvinyl ethers, poly (oxy) alkylene glycols or their monoether and polyvinyl ether copolymers, polyol esters, and polycarbonates. It is a synthetic oil mainly composed of oxygen-containing compounds or a synthetic oil mainly composed of alkylbenzenes and α-olefins.

  FIG. 2 compares the refrigeration capacity per unit volume of the R410A refrigerant and the tetrafluoropropene HFO1234yf refrigerant, which is a refrigerant having a smaller refrigeration capacity per unit volume compared to the R410A refrigerant, by experimental values using the same refrigeration apparatus. Is.

  In FIG. 2, the refrigerant temperature at the evaporator inlet, the refrigerant temperature at the evaporator outlet, the average saturation temperature at the evaporator inlet / outlet, the latent heat of vaporization at the average temperature at the evaporator inlet / outlet, the compressor suction temperature, and the compressor suction temperature The saturation gas density and the refrigeration capacity per unit volume of the evaporator (compressor suction saturated gas density × evaporation latent heat) are shown. Experimental values are shown for the R410A refrigerant, experimental values are shown for the HFO1234yf refrigerant, and the evaporator temperature when the refrigerant temperature at the evaporator inlet, the refrigerant temperature at the evaporator outlet, and the compressor suction temperature are equivalent to the R410A. The refrigeration capacity per unit volume is shown.

  As shown in FIG. 2, the refrigeration capacity per unit volume during cooling operation is 10149.72 kJ / m3 for R410A and 3722.55 kJ / m3 for HFO1234yf, and HFO1234yf is about 1 / 2.7 times that of R410A. . Therefore, in order to make the refrigerating capacity of the compressor 1 comparable to that of R410A, it is necessary to increase the volumetric flow rate per unit time by increasing the cylinder volume by about 2.7 times.

  In addition, although the method of increasing a rotation speed can be considered as a means to increase the volume flow rate per unit time of the compressor 1, it leads to the increase in the sliding loss of the compressor 1 by increasing a rotation speed, and the compressor 1 is increased. This is not preferable because the efficiency is reduced.

  On the other hand, the experimental value of HFO1234yf is lower than the experimental value of R410A for the outlet temperature of the indoor heat exchanger that acts as an evaporator and the saturated gas temperature of the suction port of the compressor. This is thought to be due to an increase in pressure loss due to an increase in the flow velocity in the pipe, resulting in a decrease in temperature, and a decrease in evaporator performance and a decrease in compressor suction density.

  Furthermore, for HFO1234yf, as shown in the result of calculating the refrigerating capacity per unit volume when it is assumed that the pressure loss is equal to that of R410A, and further the outlet temperature of the evaporator and the saturated gas temperature of the suction port of the compressor are obtained. When the pressure loss is equivalent to R410A, the latent heat of vaporization of the evaporator can be improved and the suction density of the compressor can be increased. The refrigeration capacity per unit volume is 4529.78 kJ / m3, which is about 20% of the experimental value. It has improved. Therefore, it is important to reduce the pressure loss in the piping.

  On the other hand, even during the heating operation, efficiency can be improved by reducing the pressure loss of the outdoor heat exchanger acting as an evaporator.

At this time, when the pressure loss is ΔP and the refrigerant flow velocity in the pipe is V, the equation (1) is generally established.
△ P∝V2 (1)
Therefore, in order to reduce the pressure loss, it is necessary to increase the passage area and lower the refrigerant flow rate.

  FIG. 3 is a comparison of the in-pipe flow rates of the R410A refrigerant and the HFO1234yf refrigerant with experimental values.

  FIG. 3 shows the refrigerant circulation amount, the evaporator outlet saturation density, the evaporator outlet pipe cross-sectional area (refrigerant passage area), and the refrigerant pipe flow velocity / pipe velocity ratio.

  As shown in FIG. 3, the flow velocity in the pipe during the cooling operation is about 5.4 m / s for the R410A refrigerant and about 14.4 m / s for the HFO1234yf refrigerant, and when pipes having the same passage area are used, The pressure loss of HFO1234yf refrigerant is larger than that of R410A refrigerant.

  Therefore, in order to obtain an appropriate pressure loss equivalent to R410A, it is necessary to increase the passage area.

  However, if the flow velocity in the pipe is optimized when acting as an evaporator during cooling operation, the refrigerant density is large because of the high pressure when acting as a condenser during heating operation, and the flow velocity is greatly reduced. The heat transfer coefficient decreases, and the performance deterioration due to the decrease in heat transfer coefficient is larger than the performance deterioration due to the increase in pressure loss. Therefore, in order to balance performance between cooling and heating, it is necessary not only to increase the passage area of the pipe but also to reduce the pressure loss by different methods.

  The pressure loss increases when the circulating refrigerant flows in a gas state. However, when the heat exchanger functions as an evaporator, the heat exchanger absorbs heat from the air when the liquid refrigerant evaporates, so even if the gas refrigerant flows into the heat exchanger, it does not affect the heat absorption. Therefore, when the heat exchanger acts as an evaporator, the gas and liquid separators separate the gas refrigerant and liquid refrigerant between the expansion device and the evaporator inlet, and only the liquid refrigerant flows through the evaporator. The flow rate in the pipe of the heat exchanger is reduced and the pressure loss is reduced. In addition, a gas-liquid separator is provided in the middle of the heat exchanger that acts as an evaporator to separate the gas refrigerant and liquid refrigerant, and only the liquid refrigerant flows to the remaining heat exchanger, and the gas refrigerant is bypassed to the heat exchanger outlet. Thus, the pressure loss of the heat exchanger can be reduced.

  Next, the effect | action of the bypass circuit which reduces the refrigerant | coolant pressure loss of the air conditioning apparatus by a present Example is demonstrated.

  FIG. 4 is a diagram showing the flow of the refrigerant in the cooling operation.

  During the cooling operation, the refrigerant compressed by the compressor 1 becomes a high-temperature and high-pressure refrigerant and is sent to the first outdoor heat exchanger 3 and the second outdoor heat exchanger 4 through the four-way valve 2. At this time, no refrigerant flows into the second outdoor bypass circuit 23 by the outdoor check valve 21. Then, the high-temperature and high-pressure refrigerant exchanges heat with the outside air in the first outdoor heat exchanger 3 and the second outdoor heat exchanger 4 to dissipate heat, and becomes high-pressure liquid refrigerant and is sent to the expansion device 6. In the expansion device 6, the pressure is reduced to become a low-temperature and low-pressure two-phase refrigerant. And it isolate | separates into a gas refrigerant and a liquid refrigerant in the outdoor side gas-liquid separator 7, and a gas refrigerant is the 1st outdoor bypass circuit comprised from the gas outlet piping 12 and the two-way valve 13 of the outdoor side gas-liquid separator 7. 14, flows into the low-pressure side pipe between the four-way valve 2 and the compressor 1, merges with the gas refrigerant returning from the indoor unit 25, and is sucked into the compressor 1. The liquid refrigerant separated by the outdoor gas-liquid separator 7 is sent to the indoor unit 25 through the liquid connection pipe 26. At this time, the reheat dehumidifying squeezing device 11 is in an open state and is not depressurized when the refrigerant flows through the reheat dehumidifying squeezing device 11, and the low-pressure and low-temperature liquid refrigerant is supplied from the first indoor heat exchanger 8. It exchanges heat with room air and absorbs heat, and part of it evaporates and becomes a gas-liquid two-phase low-temperature refrigerant. Then, the indoor side gas-liquid separator 10 separates the refrigerant into a gas refrigerant and a liquid refrigerant, and the gas refrigerant is an indoor bypass circuit 18 configured by the gas outlet pipe 16 and the indoor side check valve 17 of the indoor side gas-liquid separator 10. And flows to the outlet of the second indoor heat exchanger 9 and merges with the gas refrigerant flowing from the second indoor heat exchanger 9. Further, the liquid refrigerant separated by the indoor side gas-liquid separator 10 enters the second indoor heat exchanger 9 to exchange heat with the indoor air, absorbs heat, evaporates and becomes a low-temperature gas refrigerant. At this time, the room air is cooled to cool the room. Further, the gas refrigerant flowing from the second indoor heat exchanger 9 merges with the gas refrigerant flowing from the indoor bypass circuit 18, passes through the gas connection pipe 27, and passes through the four-way valve 2 to the compressor 1. Returned. At this time, the gas refrigerant separated by the outdoor gas-liquid separator 7 does not flow through the indoor unit 25, and pressure loss in the indoor unit 25 and the gas connection pipe 27 can be reduced. Further, the gas refrigerant separated by the indoor side gas-liquid separator 10 does not flow through the second indoor heat exchanger 9, and the pressure loss in the second indoor heat exchanger 9 can be reduced.

  FIG. 5 is a diagram showing the flow of the refrigerant in the heating operation.

During the heating operation, the refrigerant compressed by the compressor 1 becomes a high-temperature and high-pressure refrigerant, passes through the four-way valve 2 and the gas connection pipe 27, and is sent to the indoor unit 25. At this time, the reheat dehumidifying squeezing device 11 is in an open state and is not depressurized when the refrigerant flows through the reheat dehumidifying squeezing device 11, and the high-temperature and high-pressure refrigerant is supplied to the second indoor heat exchanger 9, Enters the indoor heat exchanger 8 and exchanges heat with the indoor air to dissipate the heat and cool to become a high-pressure liquid refrigerant. At this time, the refrigerant does not flow into the indoor bypass circuit 18 due to the indoor check valve 17. The room air is heated by the second indoor heat exchanger 9 and the first indoor heat exchanger 8 to heat the room. Thereafter, the refrigerant is sent to the expansion device 6 through the liquid connection pipe 26 and is reduced in pressure by the expansion device 6 to become a low-temperature low-pressure two-phase refrigerant. At this time, the two-way valve 13 of the first outdoor bypass circuit 14 is closed, and the refrigerant does not flow. The low-temperature and low-pressure two-phase refrigerant decompressed in the expansion device 6 exchanges heat with the outdoor air in the second outdoor heat exchanger 4 and absorbs heat. It becomes a low-temperature refrigerant. And it isolate | separates into a gas refrigerant and a liquid refrigerant in the 2nd outdoor side gas-liquid separator 5, and a gas refrigerant is comprised from the gas outlet piping 20 of the 2nd outdoor side gas-liquid separator 5, and the outdoor side non-return valve 21. The second refrigerant flows through the second outdoor bypass circuit 23 to the outlet of the first outdoor heat exchanger 3 and merges with the gas refrigerant flowing from the first outdoor heat exchanger 3. Further, the liquid refrigerant separated by the second outdoor gas-liquid separator 5 enters the first outdoor heat exchanger 3 to exchange heat with outdoor air, absorbs heat, evaporates and becomes a low-temperature gas refrigerant, The gas refrigerant flowing from the second outdoor bypass circuit 23 is merged and returned to the compressor 1 via the four-way valve 2.

  At this time, the gas refrigerant separated by the second outdoor-side gas-liquid separator 5 does not flow through the first outdoor heat exchanger 3 and reduces the pressure loss in the first outdoor heat exchanger 3. be able to.

  FIG. 6 is a diagram showing a refrigerant flow in the reheat dehumidification operation.

  During the reheat dehumidifying operation, the refrigerant compressed by the compressor 1 becomes a high-temperature and high-pressure refrigerant and is sent to the first outdoor heat exchanger 3 and the second outdoor heat exchanger 4 through the four-way valve 2. At this time, no refrigerant flows into the second outdoor bypass circuit 23 by the outdoor check valve 21. At this time, since the rotational speed of the blower is controlled to be low, the amount of heat that the heat of the high-temperature and high-pressure refrigerant radiates by exchanging heat with outside air is controlled. Then, it becomes a high-pressure gas-liquid two-phase refrigerant and is sent to the expansion device 6. At this time, the expansion device 6 is controlled to be fully opened and is not depressurized. Further, the two-way valve 13 of the first outdoor bypass circuit 14 is closed, and the refrigerant does not flow. The high-pressure two-phase refrigerant that has passed through the expansion device 6 passes through the liquid connection pipe 26 and is sent to the indoor unit 25 where it is dissipated by the first indoor heat exchanger 8 and becomes high-pressure and low-temperature liquid refrigerant. At this time, since the opening degree of the reheat dehumidifying squeezing device 11 is controlled to be small, the reheat dehumidifying squeezing device 11 is depressurized when the refrigerant flows and becomes a low-pressure low-temperature two-phase refrigerant. Then, the indoor side gas-liquid separator 10 separates the refrigerant into a gas refrigerant and a liquid refrigerant, and the gas refrigerant is an indoor bypass circuit 18 configured by the gas outlet pipe 16 and the indoor side check valve 17 of the indoor side gas-liquid separator 10. And flows to the outlet of the second indoor heat exchanger 9 and merges with the gas refrigerant flowing from the second indoor heat exchanger 9. Further, the liquid refrigerant separated by the indoor side gas-liquid separator 10 enters the second indoor heat exchanger 9 to exchange heat with the indoor air, absorbs heat, evaporates and becomes a low-temperature gas refrigerant. At this time, the indoor air is cooled and dehumidified by the second indoor heat exchanger 9, and then heated by the first indoor heat exchanger 8, so it is dehumidified without lowering the indoor temperature. The low-temperature gas refrigerant is returned to the compressor 1 through the gas connection pipe 27 and the four-way valve 2.

  In addition, as a refrigerant | coolant whose refrigerating capacity per unit volume is small compared with a R410A refrigerant | coolant and a refrigerant | coolant global warming coefficient is 5 or more and 750 or less, it can obtain by mixing R32 and HFO1234yf, for example. Since the GWP of R32 is 675 and the GWP of HFO1234yf is 4, the GWP of the mixture is 650 or less regardless of the mixing ratio.

  FIG. 7 shows the relationship between the mixing ratio of R32 and HFO1234yf and the refrigerating capacity ratio per unit volume when R410A is 1.

  FIG. 7 shows the refrigeration capacity refrigeration ratio per unit volume at 17 ° C. corresponding to the cooling operation and the refrigeration capacity refrigeration ratio per unit volume at 3 ° C. equivalent to the heating operation.

  As shown in FIG. 7, the refrigeration capacity refrigeration ratio per unit volume is smaller than that of R410A when the mixing ratio of HFO1234yf exceeds 7 wt% even at a temperature of 17 ° C. equivalent to cooling operation or 3 ° C. equivalent to heating operation. It turns out that it becomes.

  Therefore, the range of the mixing ratio when R32 and HFO1234yf are mixed is 7 wt% or less for HFO1234yf (R32 is 93 wt% or more).

  Moreover, although tetrafluoropropene HFO1234yf was demonstrated as hydrofluoroolefin, even if it uses HFO1234ze or trifluoropropene HFO1243zf, there exists the same effect.

  Furthermore, although the mixed refrigerant with hydrofluoroolefin has been described with difluoromethane R32, the same effect can be obtained by using pentafluoroethane R125 or tetrafluoroethane R134a.

  In addition, although the said Example demonstrated the case where the cooling capability rank was 4 kW, it is the same also in a different capability rank.

  Further, the present invention is important for the pressure loss of the low-pressure side heat exchanger and piping having a large specific volume of the refrigerant and a higher flow rate, but the pressure loss is also reduced for the high-pressure side part to a flow rate equivalent to R410A. It is desirable.

  As described above, the present invention reduces the efficiency of the compressor 1 by using the compressor 1 having a smaller refrigeration capacity per unit volume than the R410A refrigerant and using the compressor 1 having a larger cylinder volume than when the R410A refrigerant is used. In the cooling operation, the pressure loss of the indoor unit 25 and the gas connection pipe 27 is reduced. In the heating operation, the pressure loss of the first outdoor heat exchanger 3 is reduced. In the cooling operation, the pressure loss acts as a condenser. Providing a highly efficient air conditioning system that prevents a decrease in the heat transfer rate by preventing a decrease in the refrigerant flow rate of the outdoor heat exchanger and a decrease in the refrigerant flow rate of the indoor heat exchanger that acts as a condenser in heating operation can do.

  Next, in the above embodiment, the air-conditioning apparatus has been described. However, it is applicable only to heating that does not have a four-way valve, such as a water heater, or cooling only, such as a cooler or a freezer. Is the circuit configuration at the time of heating operation described in the above embodiment, and if it is exclusively for cooling, it may be the circuit configuration at the time of cooling operation. In that case, the indoor heat exchanger and the outdoor heat exchanger are a condenser and an evaporator. It turns out that.

  According to the present invention, it is possible to use a refrigerant having a small GWP, such as the HFO 1234yf of GWP4.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 1st outdoor heat exchanger 4 2nd outdoor heat exchanger 5 2nd outdoor side gas-liquid separator 6 Throttle device 7 Outdoor side machine liquid separator 8 1st indoor heat exchanger 9 Second indoor heat exchanger 10 Indoor side gas-liquid separator
DESCRIPTION OF SYMBOLS 11 Reheating dehumidification apparatus 12 Gas outlet piping of outdoor side gas-liquid separator 13 Two-way valve 14 First outdoor bypass circuit 15 Liquid outlet piping of outdoor side gas-liquid separator 16 Gas outlet of indoor side gas-liquid separator Piping 17 Indoor check valve 18 Indoor bypass circuit 19 Liquid outlet piping of indoor gas-liquid separator 20 Gas outlet piping of second outdoor gas-liquid separator 21 Outdoor check valve 22 Second outdoor gas-liquid Liquid outlet piping of separator 23 Second outdoor bypass circuit 24 Outdoor unit 25 Indoor unit 26 Liquid connection pipe 27 Gas connection pipe

Claims (8)

Compressor, four-way valve, outdoor heat exchanger, expansion device, liquid connection pipe, first indoor heat exchanger, reheat dehumidification expansion device, indoor side gas-liquid separator, second indoor heat exchanger, gas Connecting pipes are sequentially connected by a connecting pipe to form an annular refrigerant circuit, and during cooling operation, the refrigerant is the compressor, the four-way valve, the outdoor heat exchanger, the expansion device, the liquid connection pipe, the first Flow in the order of the indoor heat exchanger, the reheat dehumidifying expansion device, the indoor side gas-liquid separator, the second indoor heat exchanger, and the gas connection pipe, and the outlet of the reheat dehumidifying expansion device is the Connected to the indoor side gas-liquid separator, the liquid outlet pipe of the indoor side gas-liquid separator and the second indoor side heat exchanger are connected, and the gas outlet pipe of the indoor side gas-liquid separator is reverse to the indoor side A cooling / heating device connected to an outlet of the second indoor heat exchanger via a stop valve, and enclosed in the refrigerant circuit That as a refrigerant, air conditioner, characterized in that the refrigeration capacity per unit volume as compared with R410A refrigerant with little refrigerant. An outdoor gas-liquid separator is provided between the expansion device and the liquid connection pipe, and the outlet of the expansion device is connected to the outdoor gas-liquid separator during cooling operation, and the liquid in the outdoor gas-liquid separator is An outlet pipe and the liquid connection pipe are connected, and a gas outlet pipe of the outdoor gas-liquid separator is connected to a low-pressure side pipe between the four-way valve and the compressor via a two-way valve. Item 2. The air conditioning apparatus according to item 1. Compressor, four-way valve, first outdoor heat exchanger, second outdoor gas-liquid separator, second outdoor heat exchanger, expansion device, liquid connection pipe, indoor heat exchanger, gas connection pipe An annular refrigerant circuit is configured by connecting with a pipe, and during heating operation, the refrigerant is the compressor, the four-way valve, the gas connection pipe, the indoor heat exchanger, the liquid connection pipe, the expansion device, the second The outdoor heat exchanger, the second outdoor gas-liquid separator, and the first outdoor heat exchanger flow in this order, and the outlet of the second outdoor heat exchanger is the second outdoor gas-liquid separator. Is connected to a liquid outlet pipe of the second outdoor gas-liquid separator and an inlet of the first outdoor heat exchanger, and a gas outlet pipe of the second outdoor gas-liquid separator is An air conditioner connected to an outlet of the first outdoor heat exchanger via an outdoor check valve,
A cooling / heating apparatus using a refrigerant having a small refrigerating capacity per unit volume as compared with the R410A refrigerant as the refrigerant sealed in the refrigerant circuit. A compressor, a four-way valve, a first outdoor heat exchanger, a second outdoor gas-liquid separator, a second outdoor heat exchanger, a throttling device, a first outdoor gas-liquid separator, a liquid connection pipe, and The first indoor heat exchanger, the reheat dehumidifying throttling device, the indoor side gas-liquid separator, the second indoor heat exchanger, and the gas connection pipe are sequentially connected by a connection pipe to form an annular refrigerant circuit, During operation, the refrigerant is the compressor, the four-way valve, the first outdoor heat exchanger, the second outdoor gas-liquid separator, the second outdoor heat exchanger, the expansion device, and the outdoor side. A gas-liquid separator, the liquid connection pipe, the first indoor heat exchanger, the reheat dehumidifying expansion device, the indoor side gas-liquid separator, the second indoor heat exchanger, and the gas connection pipe in this order. The outlet of the throttle device is connected to the outdoor gas-liquid separator, the liquid outlet pipe of the outdoor gas-liquid separator and the liquid connection pipe are connected, The gas outlet pipe of the outdoor gas-liquid separator is connected to a low-pressure side pipe between the four-way valve and the compressor via a two-way valve, and the reheat dehumidifying throttle device is connected to the indoor gas-liquid separator. The liquid outlet pipe of the indoor side gas-liquid separator and the second indoor side heat exchanger are connected, and the gas outlet pipe of the indoor side gas-liquid separator is connected via an indoor check valve. It is connected to the outlet of the second indoor heat exchanger, and during heating operation, the refrigerant is the compressor, the four-way valve, the gas connection pipe, the second indoor heat exchanger, and the indoor gas-liquid separator. The reheat dehumidifying throttling device, the first indoor heat exchanger, the liquid connection pipe, the outdoor gas-liquid separator, the throttling device, the second outdoor heat exchanger, and the second outdoor side The gas-liquid separator and the first outdoor heat exchanger flow in this order, and the outlet of the first outdoor heat exchanger is the second outdoor air exchanger. Connected to a separator, an outlet pipe of the second outdoor gas-liquid separator and an inlet of the second outdoor heat exchanger are connected, and a gas outlet pipe of the second outdoor gas-liquid separator is An air conditioner connected to the inlet of the first outdoor heat exchanger via an outdoor check valve, and has a lower refrigeration capacity per unit volume as a refrigerant to be sealed in the refrigerant circuit than an R410A refrigerant. A cooling and heating apparatus using a refrigerant. A compressor, a condenser, a first expansion device, a first evaporator gas-liquid separator, and a second evaporator are sequentially connected to form an annular refrigerant circuit, and the refrigerant is the compressor, the condenser, and the first The throttle device, the first evaporator, the gas-liquid separator, and the second evaporator flow in this order, the outlet of the first evaporator is connected to the gas-liquid separator, and the liquid outlet pipe of the gas-liquid separator And the second evaporator are connected, and the gas outlet pipe of the gas-liquid separator is connected to the outlet of the second evaporator via a check valve, and the refrigerant sealed in the refrigerant circuit A refrigerating apparatus using a refrigerant having a refrigerating capacity per unit volume smaller than that of the R410A refrigerant. A compressor, a first condenser, a second gas-liquid separator, a second condenser, a throttling device, and an evaporator are sequentially connected to form an annular refrigerant circuit, and the refrigerant is the compressor, the first condenser, The second gas-liquid separator, the second condenser, the throttling device, and the evaporator flow in this order. The outlet of the first condenser is connected to the second gas-liquid separator, and the second gas-liquid separation The gas outlet pipe of the condenser is connected to the inlet of the second condenser, and the liquid outlet pipe of the second gas-liquid separator is connected to the outlet of the second condenser via a check valve. A refrigerating apparatus using a refrigerant having a small refrigerating capacity per unit volume as compared with the R410A refrigerant as the refrigerant sealed in the refrigerant circuit. As the refrigerant, the hydrofluoroolefin is based on tetrafluoropropene or trifluoropropene, and difluoromethane, pentafluoroethane, or tetrafluoroethane is preferably 350 so that the global warming potential is 5 or more and 750 or less. The cooling / heating apparatus according to any one of claims 1 to 4, wherein a refrigerant mixed with two components or a mixture of three components is used so as to be more preferably 150 or less. As the refrigerating machine oil used in the compressor, polyoxyalkylene glycols, polyvinyl ethers, poly (oxy) alkylene glycols or their monoether and polyvinyl ether copolymers, polyol esters, and polycarbonates containing oxygen The air conditioning apparatus according to any one of claims 1 to 4, wherein a synthetic oil mainly comprising a compound or a synthetic oil mainly comprising an alkylbenzene or an α-olefin is used.