JP6065429B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner using a refrigerant having a low global warming potential.

  Currently, HFC-based chlorofluorocarbon refrigerants that do not destroy the ozone layer are used for refrigerants such as air conditioners. However, this HFC refrigerant has a very high global warming potential and is subject to emission regulations to prevent global warming. Therefore, the use of a refrigerant with a low global warming potential has been studied. Particularly in car air conditioners, HFO-1234yf having a warming coefficient of 4 and a pressure almost equal to that of R-134A has been proposed as an alternative refrigerant for R-134a (Patent Document 1).

Japanese Patent No. 4571183

  However, HFO-1234yf has a larger specific volume of saturated gas for the same temperature than R-410A used in conventional air conditioners, and in order to obtain the same cooling capacity or heating capacity, As a result, it is necessary to increase the volume circulation amount. As a result, the refrigerant flow velocity of the pipe increases, and the pressure loss of the refrigerant increases.

  Therefore, the present invention provides an air conditioner with high energy efficiency by increasing the pipe diameter of the pipe through which the gas refrigerant of the refrigeration cycle flows when using HFO-1234yf or its mixed refrigerant in an air conditioner. With the goal.

The air conditioner of the present invention connects an outdoor unit configured by connecting a compressor, a four-way valve, an outdoor heat exchanger, and a decompressor with refrigerant pipes and an indoor unit having an indoor heat exchanger with a connecting refrigerant pipe. an air conditioner which constitutes a refrigeration cycle Te, refrigerant in the refrigeration cycle, a single refrigerant of HFO-1234y f, or as a main component HFO-1234yf, a mixed refrigerant containing R-32 less than 22% In addition, the inner diameter of the refrigerant pipe of the air conditioner having a cooling rated capacity of 4 kW or less and the gas side refrigerant pipe of the connecting refrigerant pipe is 4 kW or less for R-410A corresponding to the air conditioner. This is a pipe having an inner diameter of 9.5 mm to 14 mm, which is 1.2 to 1.8 times the gas side refrigerant pipe of the conditioner.

  Thereby, even if it uses a refrigerant | coolant with a low warming coefficient, pressure loss can be reduced and the performance equivalent to the air conditioner using conventional R-410A can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, even if it uses a refrigerant | coolant with a low warming coefficient for an air conditioner, pressure loss can be reduced and energy efficiency can be improved.

Refrigeration cycle diagram of the air conditioner in Embodiment 1 of the present invention Relationship diagram between refrigerant pipe diameter and pressure loss of air conditioner in Embodiment 1 Relationship diagram between refrigerant pipe diameter and pressure loss of other air conditioner in Embodiment 1 Relationship diagram between refrigerant pipe diameter and pressure loss of other air conditioner in Embodiment 1

  1st invention is the gas side refrigerant | coolant piping of the air conditioner whose inside diameter of the refrigerant | coolant piping of the air conditioner whose cooling rated capacity is 4 kW or less, and the gas side refrigerant | coolant piping of connection refrigerant | coolant piping is 4 kW or less for R-410A 1.2 to 1.8 times, and a pipe having an inner diameter of 9.5 mm to 14 mm, and the same performance as an air conditioner using R-410A can be obtained.

  In the second invention, the inner diameter of the refrigerant pipe of the air conditioner having a cooling rated capacity of over 4 kW and 6 kW or less and the gas-side refrigerant pipe of the connecting refrigerant pipe is over 4 kW for R-410A and 6 kW or less. It is 1.2 to 1.7 times the gas-side refrigerant piping of an air conditioner, and has an inner diameter of 13 mm to 19 mm. The same performance as an air conditioner using R-410A can be obtained. .

  In the third aspect of the invention, the inner diameter of the refrigerant pipe of the air conditioner having a cooling rated capacity of over 6 kW and 8 kW or less and the gas side refrigerant pipe of the connecting refrigerant pipe is over 6 kW for R-410A and 8 kW or less. It is 1.5 to 2.1 times the gas-side refrigerant piping of the air conditioner, and has a diameter of 16 mm to 23 mm. The same performance as an air conditioner using R-410A can be obtained. .

  In the fourth aspect of the invention, the inner diameter of the refrigerant piping of the air conditioner having a cooling rated capacity exceeding 8 kW and 24 kW or less and the gas-side refrigerant piping of the connecting refrigerant piping is exceeding 8 kW for R-410A and 24 kW or less. It is 1.5 to 2.1 times the gas-side refrigerant piping of the air conditioner, and has a diameter of 16 mm to 23 mm. The same performance as an air conditioner using R-410A can be obtained. .

  In the fifth aspect of the present invention, the inner diameter of the refrigerant pipe of the air conditioner having a cooling rated capacity of 4 kW or less and the gas side refrigerant pipe of the connection refrigerant pipe is 4 kW or less for R-410A corresponding to the air conditioner. It is 1 to 1.2 times the gas-side refrigerant piping of the conditioner, and has a diameter of 7.9 mm to 10 mm, and the same performance as an air conditioner using R-410A can be obtained.

  In the sixth aspect of the invention, the inner diameter of the refrigerant pipe of the air conditioner and the connecting refrigerant pipe of the air conditioner whose cooling rated capacity exceeds 4 kW and 6 kW or less exceeds 4 kW for R-410A and is 6 kW or less. It is 1 to 1.25 times the gas side refrigerant pipe of the air conditioner and has a diameter of 11 mm to 14 mm, and the same performance as an air conditioner using R-410A can be obtained.

In the seventh invention, the inner diameter of the gas side refrigerant pipe of the refrigerant pipe of the air conditioner and the connecting refrigerant pipe of the air conditioner whose cooling rated capacity exceeds 6 kW and 8 kW or less exceeds 6 kW for R-410A and is 8 kW or less. This is a pipe having an inner diameter of 13 mm to 17 mm, which is 1.2 to 1.5 times the gas side refrigerant pipe of the air conditioner, and can achieve the same performance as R-410A.

In the eighth aspect of the invention, the inner diameter of the refrigerant pipe of the air conditioner and the connecting refrigerant pipe of the air conditioner whose cooling rated capacity exceeds 8 kW and 24 kW or less exceeds 8 kW for R-410A and is 24 kW or less. This is a pipe having an inner diameter of 13 mm to 17 mm, which is 1.2 to 1.5 times the gas side refrigerant pipe of the air conditioner, and can achieve the same performance as R-410A.

According to a ninth aspect of the present invention, in the air conditioner of the first to eighth aspects, the single refrigerant or the refrigerant is adjusted so that the global warming potential is 3 or more and 750 or less, preferably 350 or less, more preferably 150 or less. one using a two-component mixing combined refrigerant, can contribute to the prevention of global warming.

  According to a tenth aspect of the present invention, in the air conditioner of the first to ninth aspects, polyoxyalkylene glycols, polyvinyl ethers, poly (oxy) alkylene glycols or monoethers thereof and polyvinyl ethers are used as refrigerating machine oil used in the compressor. A synthetic oil mainly composed of an oxygen-containing compound of any of the copolymers, polyol esters, and polycarbonates, or a synthetic oil mainly composed of alkylbenzenes and olefins, or a mineral oil, This contributes to the prevention of global warming and the improvement of the reliability of air conditioners.

  Embodiments of the present invention will be described below. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a refrigeration cycle diagram of an air conditioner according to Embodiment 1 of the present invention.

  In FIG. 1, this air conditioning includes a compressor 1 that compresses a refrigerant, a four-way valve 2 that switches a refrigerant circuit during cooling and heating operation, an outdoor heat exchanger 3 that exchanges heat between the refrigerant and the outside air, and a decompressor that decompresses the refrigerant. 4 are connected by a refrigerant pipe 10 to constitute an outdoor unit 5, and an indoor unit 7 having an indoor heat exchanger 6 for exchanging heat between the refrigerant and room air is connected to the outdoor unit 5 by a liquid-side connecting refrigerant pipe. 8. It is configured to be connected annularly by a gas side connecting refrigerant pipe 9.

  The refrigerant circuit constituting the air conditioner according to the present embodiment is filled with a refrigerant having a low warming coefficient, and hydrofluoroolefin as an example of the refrigerant having a low warming coefficient is tetrafluoropropene (HFO-1234yf, HFO-1234ze, HFO-1243zf) or trifluoropropene as a base component, using a mixed refrigerant containing less than 22% of difluoromethane (R-32), and a gas-side connection in which the cooling capacity of the air conditioner is 4 kW or less The inner diameter of the refrigerant pipe 9 is 9.5 mm to 14 mm.

  During the cooling operation, the refrigerant compressed by the compressor 1 becomes a high-temperature and high-pressure refrigerant and is sent to the outdoor heat exchanger 3 through the four-way valve 2. Then, it exchanges heat with the outside air to dissipate heat, and becomes a high-pressure liquid refrigerant, which is sent to the decompressor 4. In the pressure reducer 4, the pressure is reduced to form a low-temperature and low-pressure two-phase refrigerant, which is sent to the indoor unit 7 through the liquid side connection refrigerant pipe 8. In the indoor unit 7, the refrigerant enters the indoor heat exchanger 6, exchanges heat with 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 refrigerant returns to the outdoor unit 5 through the gas side connection refrigerant pipe 9 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 side connection refrigerant pipe 9, and is sent to the indoor unit 7. The high-temperature and high-pressure refrigerant enters the indoor heat exchanger 6, exchanges heat with indoor air, dissipates heat, and is cooled to become high-pressure liquid refrigerant. At this time, the room air is heated to heat the room. Thereafter, the refrigerant passes through the liquid side connecting refrigerant pipe 8 and is sent to the decompressor 4, and is decompressed in the decompressor 4 to become a low-temperature and low-pressure two-phase refrigerant, and is sent to the outdoor heat exchanger 3 to exchange heat with the outside air. Then, it evaporates and returns to the compressor 1 via the four-way valve 2.

  Next, the effect | action by the piping diameter of the air conditioner by this Embodiment is demonstrated.

  When the refrigerant flow in the gas side connection refrigerant pipe 9 of the air conditioner is in a laminar flow state, the pressure loss of the refrigerant flowing through the gas side connection refrigerant pipe 9 is expressed by the following equation (1).

Where ΔP: pressure loss
F: Coefficient of friction
L: Pipe length
D: Diameter in the pipe
Ρ: Density
U: Flow velocity
V: Kinematic viscosity coefficient
Ν: Specific volume
：: Viscosity coefficient
Φ: Volumetric refrigerating capacity
ΔH: Freezing effect
A: Pipe cross-sectional area For this equation, FIG. 2 shows a pipe length: 5 m, cooling rated capacity: 4 kW, refrigerant R-410A, R-32 / 1234yf = 22/78 wt%, 50/50 wt% saturated gas refrigerant The pressure loss of the R-410A pipe outer diameter of 9.52 mm and the pipe inner diameter of 7.93 mm is represented as 100 with the pipe diameter on the horizontal axis.

  From FIG. 2, R-1234yf has a pipe inner diameter of 12 mm or more, R-32 / R-1234yf = 22/78 wt% has a pipe inner diameter of 10 mm or more, and R-32 / R-1234yf = 50/50 wt% The inner diameter of the pipe is 8.9 mm or more, which is equivalent to the pressure loss of R-410A.

  Further, since the refrigerant pipe used for the air conditioner normally has a pipe outer diameter that is an integral multiple of a value obtained by dividing 25.4 mm (1 inch) by 8 or 16, R-1234yf and R-32 / R-1234yf = 22 / 78wy% is a pipe outer diameter of 11.1 mm or more (if the pipe wall thickness is 0.8 mm, the inner diameter is 9.5 mm), and R-32 / R-1234yf = 50/50 wt% If a pipe with a pipe outer diameter of 9.5 mm or more (inner diameter of 7.9 mm when the pipe wall thickness is 0.8 mm) is used, the pressure loss will be almost equal to or less than that of R-410A, and performance degradation will be prevented. Can do.

 Here, the above “substantially equal to or less than the pressure loss of R-410A” is regarded as ± 20% when the pressure loss of R-410A under the above conditions is set to 100 in the present invention. That is, each pipe inner diameter of R-1234yf, R-32 / R-1234yf = 22/78 wt% and R-32 / R-1234yf = 50/50 wt% is a pressure loss of a pipe inner diameter of R-410A of 7.9 mm. The former is 1.2 to 1.8 times, the inner diameter is 9.5 mm to 14 mm (in the case of R-1234yf, R-32 / R-1234yf = 22/78 wt%), and the latter is 1 The inner diameter of 7.9 mm to 10 mm (in the case of R-32 / R-1234yf = 50/50 wt%) is -1.2 times.

  Further, in FIG. 3, the pressure loss of the saturated gas refrigerant of pipe length: 5 m, cooling capacity: 6 kW, refrigerant R-410A, R-32 / 1234yf = 22/78 wt%, 50/50 wt% is calculated. On the horizontal axis, the pressure loss of the pipe outer diameter of R-410A 12.7 mm and the pipe inner diameter 11.1 mm is represented as 100.

  From FIG. 3, R-1234yf has a pipe inner diameter of 17 mm or more, R-32 / R-1234yf = 20/80 wt% has a pipe inner diameter of 15 mm or more, and R-32 / R-1234yf = 50/50 wt% The inner diameter of the pipe is 12 mm or more, which is equivalent to the pressure loss of R-410A.

  In addition, since the refrigerant outer diameter generally used is a pipe outer diameter that is an integral multiple of a value obtained by dividing 25.4 mm by 8, R-1234yf has a pipe outer diameter of 15.5 mm or more (the pipe wall thickness is 1mm, the inner diameter is 17.5mm), R-32 / R-1234yf = 22 / 78wt%, the pipe outer diameter is 13.9mm or more (when the pipe wall thickness is 1mm, the inner diameter is 15.9mm) -32 / R-1234yf = 50/50 wt%, when using a pipe with a pipe outer diameter of 11.1 mm or more (when the pipe thickness is 0.8 mm, the inner diameter is 12.7 mm), the pressure loss is R-410A As a result, it is possible to prevent performance degradation.

  Here, as in the case described above, “substantially equal to or less than the pressure loss of R-410A” is considered to be ± 20% in the present invention when the pressure loss of R-410A under the above conditions is 100. The pipe inner diameters of the respective values, that is, R-1234yf, R-32 / R-1234yf = 22/78 wt%, and R-32 / R-1234yf = 50/50 wt% are the pipe inner diameter 11 of R-410A. When the pressure loss of 1 mm is 100, the former is 1.2 to 1.7 times, and the inner diameter of 13 mm to 19 mm (in the case of R-1234yf, R-32 / R-1234yf = 22/78 wt%), The latter is 1 to 1.25 times and has an inner diameter of 11 mm to 14 mm (in the case of R-32 / R-1234yf = 50/50 wt%).

  Further, FIG. 4 shows the pipe length: 5 m, the cooling capacity: 8 kW, the refrigerant R-410A, the R-32 / 1234yf = 22/78 wt%, the pressure loss of the saturated gas refrigerant of 50/50 wt%, and the pipe diameter , The pressure loss of the pipe outer diameter of 15.9 mm and the pipe inner diameter of 13.9 mm of R-410A is represented as 100.

  From FIG. 4, R-1234yf has a pipe inner diameter of 21 mm or more, R-32 / R-1234yf = 22/78 wt% has a pipe inner diameter of 18 mm or more, and R-32 / R-1234yf = 50/50 wt% The inner diameter of the pipe is 15 mm or more, which is equal to or less than the pressure loss of R-410A.

  The refrigerant pipe used normally has a pipe outer diameter that is an integral multiple of the value obtained by dividing 25.4 mm by 8; therefore, R-1234yf has a pipe outer diameter of 19.1 mm or more, and R-32 / R -1234yf = 22/78 wt% is a pipe outer diameter of 16.7 mm or more, R-32 / R-1234yf = 50/50 wt% is a pressure loss if a pipe with a pipe outer diameter of 13.9 mm or more is used. Becomes equal to or less than that of R-410A, and performance degradation can be prevented.

  Here, as in the case described above, “substantially equal to or less than the pressure loss of R-410A” is considered to be ± 20% in the present invention when the pressure loss of R-410A under the above conditions is 100. The pipe inner diameters of the respective values, that is, R-1234yf, R-32 / R-1234yf = 22/78 wt%, and R-32 / R-1234yf = 50/50 wt% are the pipe inner diameter 13 of R-410A. When the pressure loss of .9 mm is 100, the former is 1.5 to 2.1 times, and the inner diameter is 16 mm to 23 mm (in the case of R-1234yf, R-32 / R-1234yf = 22/78 wt%), The latter is 1.2 to 1.5 and has an inner diameter of 13 mm to 17 mm (in the case of R-32 / R-1234yf = 50/50 wt%).

In addition, even when the pipe length is 5 m and the cooling rated capacity is 8 kW or more and 24 kW or less, from the result of calculation by the above formula 1, it is assumed that the pressure loss of R-410A is set to ± 20% when 100, R-1234yf, R-32 / R-1234yf = 22/78 wt%, R-3
The inner diameter of each pipe of 2 / R-1234yf = 50 / 50wt% is 1.5 to 2.1 times the former, and the inner diameter of 16mm to 23mm (R-1234yf, R-32 / R-1234yf = 22 / 78wt) %)), The latter is 1.2 to 1.5 times, and the inner diameter is 13 mm to 17 mm or more (in the case of R-32 / R-1234yf = 50/50 wt%).

  In addition, the same effect can be obtained even if the piping through which the gas refrigerant of the outdoor unit 5 and the indoor unit 7 flows has the same piping diameter as described above.

  In addition, the mixed refrigerant used in the air conditioner of this embodiment has a GWP of 3 or more and 750 or less, preferably 350 or less, and more preferably 150 or less. It is prepared by two-component mixing or three-component mixing. As a result, even if a refrigerant that cannot be recovered is released into the atmosphere, the effect on global warming can be kept to a minimum.

  The compressor oil used in the compressor may include any of polyoxyalkylene glycols, polyvinyl ethers, poly (oxy) alkylene glycols or their monoether and polyvinyl ether copolymers, polyol esters, and polycarbonates. A synthetic oil mainly composed of an oxygen compound, a synthetic oil mainly composed of alkylbenzenes and soot olefins, or a mineral oil is used, which can contribute to improving the reliability of the air conditioner.

  ADVANTAGE OF THE INVENTION According to this invention, the high efficiency of the refrigerating cycle using a low GWP refrigerant | coolant can be aimed at, and it can mount in various apparatuses, such as a heat pump hot water heater, and can contribute to global warming prevention.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Outdoor heat exchanger 4 Pressure reducer 5 Outdoor unit 6 Indoor heat exchanger 7 Indoor unit 8 Liquid side connection refrigerant | coolant piping 9 Gas side connection refrigerant | coolant piping

Claims (10)

An air conditioner in which a compressor, a four-way valve, an outdoor heat exchanger, and a decompressor are connected by refrigerant pipes, and an outdoor unit and an indoor unit having an indoor heat exchanger are connected by a refrigerant pipe to form a refrigeration cycle. a machine, refrigerant in the refrigeration cycle, a single refrigerant of HFO-1234y f, or as a main component HFO-1234yf, with a mixed refrigerant containing R-32 less than 22%, the cooling rated capacity 4kW The inner diameter of the refrigerant pipe of the air conditioner and the gas side refrigerant pipe of the connecting refrigerant pipe which are below is 4 kW or less for the R-410A corresponding to the air conditioner. An air conditioner characterized by being a pipe having an inner diameter of 9.5 mm to 14 mm at 1.2 to 1.8 times. An air having a refrigeration cycle configured by connecting an outdoor unit configured by connecting a compressor, a four-way valve, an outdoor heat exchanger, and a decompressor with refrigerant pipes and an indoor unit having an indoor heat exchanger by connecting refrigerant pipes a conditioner, a refrigerant of the refrigeration cycle, a single refrigerant of HFO-1234y f, or as a main component HFO-1234yf, with a mixed refrigerant containing R-32 less than 22%, the cooling rated capacity The inner diameter of the refrigerant pipe of the air conditioner that exceeds 4 kW and 6 kW or less and the gas-side refrigerant pipe of the connection refrigerant pipe exceeds 4 kW for R-410A corresponding to the air conditioner and is 6 kW or less. An air conditioner characterized by being a pipe having an inner diameter of 13 mm to 19 mm, which is 1.2 to 1.7 times the gas side refrigerant pipe of the air conditioner. An air having a refrigeration cycle configured by connecting an outdoor unit configured by connecting a compressor, a four-way valve, an outdoor heat exchanger, and a decompressor with refrigerant pipes and an indoor unit having an indoor heat exchanger by connecting refrigerant pipes a conditioner, a refrigerant of the refrigeration cycle, a single refrigerant of HFO-1234y f, or as a main component HFO-1234yf, with a mixed refrigerant containing R-32 less than 22%, the cooling rated capacity The internal diameter of the refrigerant pipe of the air conditioner that exceeds 6 kW and 8 kW or less and the gas-side refrigerant pipe of the connection refrigerant pipe exceeds 6 kW for R-410A corresponding to the air conditioner and is 8 kW or less. An air conditioner characterized by being a pipe having an inner diameter of 16 mm to 23 mm, which is 1.5 to 2.1 times the gas side refrigerant pipe of the air conditioner. An air having a refrigeration cycle configured by connecting an outdoor unit configured by connecting a compressor, a four-way valve, an outdoor heat exchanger, and a decompressor with refrigerant pipes and an indoor unit having an indoor heat exchanger by connecting refrigerant pipes a conditioner, a refrigerant of the refrigeration cycle, a single refrigerant of HFO-1234y f, or as a main component HFO-1234yf, with a mixed refrigerant containing R-32 less than 22%, the cooling rated capacity The internal diameter of the refrigerant pipe of the air conditioner that exceeds 8 kW and 24 kW or less and the gas-side refrigerant pipe of the connection refrigerant pipe exceeds 8 kW for R-410A corresponding to the air conditioner and is 24 kW or less. An air conditioner characterized by being a pipe having an inner diameter of 16 mm to 23 mm, which is 1.5 to 2.1 times the gas side refrigerant pipe of the air conditioner. An air conditioner in which a compressor, a four-way valve, an outdoor heat exchanger, and a decompressor are connected by refrigerant pipes, and an outdoor unit and an indoor unit having an indoor heat exchanger are connected by a refrigerant pipe to form a refrigeration cycle. The refrigerant of the refrigeration cycle is a mixed refrigerant containing HFO-1234yf as a main component and containing R-32 in a range of 22% to 50% and having a cooling rated capacity of 4 kW or less. The inner diameter of the refrigerant pipe and the connecting refrigerant pipe of the gas side refrigerant pipe is 1 to 1.2 times that of an air conditioner gas side refrigerant pipe of 4 kW or less for R-410A, and the inner diameter is 7.9 mm to 10 mm. An air conditioner characterized by its piping. An air conditioner in which a compressor, a four-way valve, an outdoor heat exchanger, and a decompressor are connected by refrigerant pipes, and an outdoor unit and an indoor unit having an indoor heat exchanger are connected by a refrigerant pipe to form a refrigeration cycle. The refrigerant in the refrigeration cycle is a mixed refrigerant containing HFO-1234yf as a main component and containing R-32 in a range of 22% to 50%, and has a cooling rated capacity exceeding 4 kW and 6 kW or less. The inside diameter of the refrigerant pipe of the air conditioner and the gas side refrigerant pipe of the connecting refrigerant pipe is 1 to 1.25 times the gas side refrigerant pipe of the air conditioner exceeding 4 kW for R-410A and 6 kW or less. An air conditioner characterized in that the pipe has an inner diameter of 11 mm to 14 mm. An air conditioner in which a compressor, a four-way valve, an outdoor heat exchanger, and a decompressor are connected by refrigerant pipes, and an outdoor unit and an indoor unit having an indoor heat exchanger are connected by a refrigerant pipe to form a refrigeration cycle. The refrigerant of the refrigeration cycle is a mixed refrigerant containing HFO-1234y f as a main component and containing R-32 in a range of 22% to 50%, and has a cooling rated capacity exceeding 6 kW and 8 kW or less. 1.2-1.5 of the gas side refrigerant | coolant piping of the air conditioner whose internal diameter of the said refrigerant | coolant piping of the said air conditioner and the gas side refrigerant | coolant piping of the said connection refrigerant | coolant piping exceeds 6 kW for R-410A, and is 8 kW or less. An air conditioner characterized in that the pipe has an inner diameter of 13 mm to 17 mm. An air conditioner in which a compressor, a four-way valve, an outdoor heat exchanger, and a decompressor are connected by refrigerant pipes, and an outdoor unit and an indoor unit having an indoor heat exchanger are connected by a refrigerant pipe to form a refrigeration cycle. The refrigerant of the refrigeration cycle is a mixed refrigerant containing HFO-1234yf as a main component and containing R-32 in a range of 22% to 50%, and has a cooling rated capacity of more than 8 kW and 24 kW or less. The inner diameters of the gas side refrigerant pipes of the air conditioner, wherein the refrigerant pipes of the air conditioner and the gas side refrigerant pipes of the connecting refrigerant pipes exceed 8 kW for R-410A corresponding to the air conditioner and are 24 kW or less. An air conditioner characterized by being a pipe having an inner diameter of 1.2 mm to 1.5 times and an inner diameter of 13 mm to 17 mm. Refrigerant is below 750 in global warming potential is 3 or more, preferably 350 or less, as more preferably of 150 or less, claims, characterized in that using a single refrigerant or a two-component mixing combined refrigerant The air conditioner according to any one of 1 to 8. As a refrigerating machine oil used in a compressor, polyoxyalkylene glycols, polyvinyl ethers, poly (oxy) alkylene glycols or their monoether and polyvinyl ether copolymers, polyol esters, and polycarbonate oxygenates The air conditioner according to any one of claims 1 to 9, characterized in that a synthetic oil mainly composed of benzene, a synthetic oil mainly composed of alkylbenzenes and soot olefins, or a mineral oil is used.

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