JP2010032109A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner having a dehumidification valve in the middle of piping of an indoor heat exchanger, reducing refrigerant pressure loss within piping of an outdoor heat exchanger, improving outdoor heat exchange performance during heating operation and having high energy efficiency. <P>SOLUTION: A gas-liquid separator 9 is provided in the middle of the refrigerant piping of the outdoor heat exchanger 6, and a bypass pipe 12 is provided to make separated gas refrigerant merge to outlet piping 10 of the outdoor heat exchanger 6 via a flow rate control valve 11. By performing control to adjust the opening of the flow rate control valve 11 in accordance with the rotational frequency of a compressor 1, pressure loss of a refrigerant made to flow within the outdoor heat exchanger 6 is reduced, so as to improve heating performance. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an air conditioner equipped with an outdoor heat exchanger suitable for improving performance during heating operation in an outdoor heat exchanger for a heat pump type air conditioner, and further controls to improve dehumidification performance during dehumidification operation It is related with the air conditioner provided with.

  As an air conditioner that is often used in general households, an indoor unit and an outdoor unit are configured separately, and a heat exchanger for exchanging heat between the air and the refrigerant and a blower that sends out air are contained in the indoor unit. In the outdoor unit, a heat exchanger and a blower for exchanging heat between the air and the refrigerant, a compressor for circulating the refrigerant, a decompressor for depressurizing the refrigerant, and the like are installed. By connecting the refrigerant flow path between the indoor unit and the outdoor unit using a connection pipe, the refrigerant goes back and forth between the indoor unit and the outdoor unit to establish a refrigeration cycle.

  In the air conditioner of this configuration, cooling operation, heating operation and dehumidification operation are performed by changing the flow direction of the refrigerant with a refrigerant flow path switching valve or the like, and research for energy saving regarding these operating conditions has been conducted. It is actively done.

  Effective means of energy saving include increasing the size of the heat exchanger, increasing the fan air flow, and reducing refrigerant pressure loss in the piping. Especially for air conditioners with large heating capacity, the pressure of the refrigerant in the piping A device has been devised to improve the performance without reducing the size of the heat exchanger by reducing the loss.

  As an effective means of reducing the pressure loss of the refrigerant in the refrigerant pipe, there is a system in which a plurality of refrigerant flow paths are arranged to reduce the refrigerant flow velocity in the pipe, but this occurs when the refrigerant is divided. It is necessary to devise the flow rate balance of each flow path.

  As a conventional technology to improve the performance by reducing the refrigerant pressure loss in the evaporator and bypassing the gas component that hardly contributes to the heat exchange performance to the heat exchanger outlet, the heat exchanger is equipped with a gas-liquid separator There are some which improve performance (for example, refer to patent documents 1). In Patent Document 1, a gas-liquid separator is provided in the middle of the refrigerant pipe from the inlet to the outlet of the heat exchanger, and gas components are extracted and bypassed to the heat exchanger outlet pipe, thereby improving the performance as an evaporator. .

JP 2002-372323 A

  However, in Patent Document 1, a check valve is provided in the gas bypass pipe so that the refrigerant flows in the reverse direction, that is, the refrigerant bypass when acting as a condenser is devised, and a constant refrigerant circulation amount is provided. Alternatively, the heat exchanger can be effectively operated in the state of a specific refrigerant, but there is no contrivance when the refrigerant circulation amount or the refrigerant state changes, and depending on the operating conditions, it is bypassed by liquid-gas mixing. In such a case, the gas bypass amount cannot be sufficiently secured, and the flow rate may be unbalanced when the refrigerant flow is diverted to deteriorate the performance.

  Therefore, the present invention takes the above circumstances into consideration, and includes a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, an outdoor heat exchanger, etc., each connected by a refrigerant pipe or the like to form a refrigerant circuit, An air conditioner that can perform cooling, heating, and dehumidifying operation by circulating the refrigerant, and the indoor heat exchanger includes a dehumidifying valve that can depressurize the refrigerant by constricting the valve in the middle of the refrigerant piping path. The dehumidifying valve is installed in the refrigerant flow direction during the cooling operation, such that the indoor heat exchanger upstream of the dehumidifying valve is a first indoor heat exchanger, the downstream indoor heat exchanger is a second indoor heat exchanger, and so on. An air conditioner that is divided into two and is depressurized by the dehumidifying valve so that one is a condenser and the other is an evaporator. In claim 1, in the refrigerant flow direction during heating operation In contrast, in the vicinity of the refrigerant pipe inlet of the outdoor heat exchanger. After diverting to the flow path, the refrigerant is once merged at approximately the midpoint of the refrigerant pipe path from the refrigerant inlet pipe to the refrigerant outlet pipe of the outdoor heat exchanger, and a gas-liquid separator is provided downstream thereof, The gas-liquid separator upstream side is the first outdoor heat exchanger, the downstream side is the second outdoor heat exchanger, and the separated gas refrigerant is joined to the refrigerant outlet pipe of the outdoor heat exchanger via the flow rate adjusting valve. A bypass pipe is provided, and control for adjusting the opening of the flow rate adjusting valve according to the rotational speed of the compressor is provided.

  According to a second aspect of the present invention, the refrigerant channel pipe diameter of the second outdoor heat exchanger is made smaller than the refrigerant channel pipe diameter of the first outdoor heat exchanger, and the pressure when a small diameter tube is used. The number of diversions of the refrigerant flow path is set so that the loss is smaller than when the same refrigerant flow path pipe diameter as that of the first outdoor heat exchanger is used.

In claim 3, in addition to the above-described invention, when gas-liquid separation is applied in the refrigerant flow direction during heating operation, the pipe connected to the gas-liquid separator is (cross-sectional area of the inflow pipe) ≈ (gas refrigerant) Cross-sectional area of outflow piping) + (cross-sectional area of outflow piping of liquid refrigerant)
(Cross sectional area of gas refrigerant outflow pipe) <(Cross sectional area of liquid refrigerant outflow pipe)
It has the gas-liquid separator which satisfy | fills these conditions.

  According to a fourth aspect of the present invention, in addition to the above-described invention, each refrigerant flow path in the second outdoor heat exchanger is divided when the refrigerant pipe that is substantially liquid refrigerant flowing out from the gas-liquid separator is divided into a plurality of flow paths. The second outdoor heat exchanger inlet refrigerant pipe diameter of each flow path when the flow is divided into the plurality of flow paths is made different depending on the heat exchange capability.

  In claim 5, according to the heat exchange capacity of each flow path in the second outdoor heat exchanger when the refrigerant pipe that is substantially liquid refrigerant flowing out from the gas-liquid separator is divided into a plurality of flow paths, The length to the refrigerant | coolant exit of each flow path was adjusted, It is characterized by the above-mentioned.

  In the air conditioner according to any one of claims 1 to 5, the dehumidifying valve is throttled in the same refrigerant flow direction as in the cooling operation during the dehumidifying operation, and at the same time, the bypass piping path of the gas-liquid separator It is characterized by having a control for opening a flow rate adjusting valve installed on the way.

  According to a seventh aspect of the present invention, the gas-liquid separator has a cylindrical shape and an inner diameter of 35 mm or more.

  According to the first aspect of the present invention, there is provided a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, an outdoor heat exchanger, etc., each connected by a refrigerant pipe or the like to form a refrigerant circuit. Is an air conditioner that can perform cooling, heating, and dehumidifying operations, and the indoor heat exchanger is provided with a dehumidifying valve that can depressurize the refrigerant by constricting the valve in the middle of the refrigerant piping path. The indoor heat exchanger on the upstream side of the dehumidifying valve in the refrigerant flow direction during the cooling operation sandwiches the dehumidifying valve so that the indoor heat exchanger on the downstream side is called the second indoor heat exchanger. Is an air conditioner that can be divided into two by depressurizing with the dehumidifying valve and using one as a condenser and the other as an evaporator. The outdoor heat exchange with respect to the direction of refrigerant flow during heating operation After diverting to multiple flow paths near the refrigerant piping inlet Refrigerants are temporarily joined at approximately the midpoint of the refrigerant piping path from the refrigerant inlet pipe to the refrigerant outlet pipe of the outdoor heat exchanger, and a gas-liquid separator is provided on the downstream side, and the upstream side of the gas-liquid separator is connected to the first side. 1 outdoor heat exchanger, the downstream side is a second outdoor heat exchanger, and a bypass pipe is provided so that the separated gas refrigerant merges with the refrigerant outlet pipe of the outdoor heat exchanger via the flow rate adjusting valve, and the compressor An air conditioner comprising a control for adjusting the opening degree of the flow rate adjusting valve in accordance with the number of rotations of the refrigerant, and a configuration in which the refrigerant from which gas components are substantially removed by passing through the gas-liquid separator is again divided into a plurality of flow paths. By bypassing the gas refrigerant in the machine, it is possible to eliminate the imbalance in refrigerant distribution when diverting into multiple flow paths in the gas-liquid mixed refrigerant state that has occurred in the past, and to improve the heat exchange performance as an evaporator Almost Was not gas components appropriately bypassing, it is possible to improve the performance of the evaporator.

  The effect of claim 2 is that the refrigerant channel pipe diameter of the second outdoor heat exchanger is made smaller than the refrigerant channel pipe diameter of the first outdoor heat exchanger, and a thin pipe is used. By setting the number of diversions of the refrigerant flow path so that the pressure loss in this case becomes smaller than when the same refrigerant flow path pipe diameter as that of the first outdoor heat exchanger is used, a small diameter pipe as a heat exchanger The heat transfer performance can be improved by increasing the wetting tab length of the refrigerant in the tube, and the pressure loss when acting as an evaporator can be reduced by dividing the refrigerant into multiple heat exchanges. The performance of the heat exchanger can be improved when it is comprehensively evaluated including the case where the condenser is used as a condenser.

The effect of claim 3 is that when gas-liquid separation is applied in the refrigerant flow direction during heating operation, the pipe connected to the gas-liquid separator is (the cross-sectional area of the inflow pipe) ≈ (the gas refrigerant outflow pipe (Cross sectional area) + (Cross sectional area of liquid refrigerant outflow piping)
(Cross sectional area of gas refrigerant outflow pipe) <(Cross sectional area of liquid refrigerant outflow pipe)
By having the gas-liquid separator that satisfies the above condition, the refrigerant flowing in the two-phase flow can be easily separated into the gas refrigerant and the liquid refrigerant, and the performance as a heat exchanger can be promoted.

  According to the fourth aspect of the present invention, when the refrigerant that has become substantially liquid refrigerant flowing out of the gas-liquid separator is divided into a plurality of flow paths, heat exchange of each refrigerant flow path in the second outdoor heat exchanger is performed. In consideration of capacity, that is, wind speed distribution, etc., the inlet pipe diameter of each flow path is set to a different diameter so that the heat exchanger outlet temperature of each flow path becomes substantially the same refrigerant temperature. Thus, the diversion ratio can be adjusted, and the heat exchange ratio after diversion to each flow path can be set optimally.

  In addition, as an effect of claim 5, when the refrigerant that has become substantially liquid refrigerant flowing out of the gas-liquid separator is divided into a plurality of flow paths, heat exchange of each refrigerant flow path in the second outdoor heat exchanger By considering the capacity, that is, the wind speed distribution, etc., the refrigerant pipe length from the inlet to the outlet of each refrigerant flow path is set so that the heat exchanger outlet temperature of each flow path becomes substantially the same refrigerant temperature. The same effect as that obtained in item 4 is obtained.

  Further, as an effect of the sixth aspect, the dehumidifying valve is throttled in the same refrigerant flow direction as in the cooling operation during the dehumidifying operation, and at the same time, the flow rate adjusting valve installed in the middle of the bypass piping path of the gas-liquid separator is opened. By providing the control, it is possible to eliminate the refrigerant shortage phenomenon caused by the liquid pool in the outdoor heat exchanger during the dehumidifying operation, which has occurred in the past, and to improve the dehumidifying performance.

  Further, as an effect of claim 7, the gas-liquid separator has a cylindrical shape, and at least its inner diameter is set to about 35 mm or more, so that the refrigerant flowing into the gas-liquid separator in a gas-liquid two-phase flow can be obtained. Separation performance when separating into gas refrigerant and liquid refrigerant can be improved, and the performance of an air conditioner having a gas-liquid separator can be improved.

  Equipped with a compressor, four-way valve, indoor heat exchanger, expansion valve, outdoor heat exchanger, etc., connected to each other by refrigerant piping, etc. to form a refrigerant circuit and circulate the refrigerant for cooling, heating and dehumidifying operation The indoor heat exchanger is provided with a dehumidifying valve that can depressurize the refrigerant by constricting the valve in the middle of the refrigerant piping path, and the dehumidifying valve in the refrigerant flow direction during cooling operation. The indoor heat exchanger on the upstream side of the valve is divided into two, with the dehumidifying valve sandwiched between the first indoor heat exchanger, the downstream indoor heat exchanger, and the second indoor heat exchanger. By reducing the pressure, an air conditioner that can be used as a condenser and the other as an evaporator, with multiple flow paths in the vicinity of the refrigerant pipe inlet of the outdoor heat exchanger with respect to the refrigerant flow direction during heating operation. After diversion, the refrigerant is cooled from the refrigerant inlet pipe of the outdoor heat exchanger. The refrigerant is once merged at approximately the midpoint of the refrigerant piping path up to the outlet pipe, and a gas-liquid separator is provided on the downstream side. The upstream side of the gas-liquid separator is the first outdoor heat exchanger, and the downstream side is the first outdoor heat exchanger. A two-way outdoor heat exchanger is provided, and a bypass pipe is provided so that the separated gas refrigerant merges with the refrigerant outlet pipe of the outdoor heat exchanger via the flow rate adjusting valve, and the flow rate adjusting valve of the flow rate adjusting valve is adjusted according to the rotational speed of the compressor. By providing the control to adjust the opening degree, it is possible to improve the refrigerant distribution performance when the outdoor heat exchanger is used as an evaporator, and to reduce the pressure loss of the refrigerant. Realized the purpose.

  FIG. 1 is a cycle configuration diagram of an air conditioner according to the present invention. If it demonstrates with the flow of the refrigerant | coolant at the time of heating operation, the refrigerant | coolant made into high temperature and high pressure gas by the compressor 1 will flow in into the indoor heat exchanger 3 via the four-way valve 2, and the indoor ventilation fan 4 in the indoor heat exchanger 3 will be described. The air is exchanged with the air to be condensed into liquid refrigerant, and becomes a low-temperature, low-pressure two-phase flow refrigerant by the expansion valve 5. Then, the two-phase flow refrigerant having a low temperature and a low pressure flows into the outdoor heat exchanger 6, exchanges heat with the air sent by the outdoor blower fan 7, and then returns to the compressor 1 again through the four-way valve 2.

  In the outdoor heat exchanger 6, after the refrigerant is divided in the vicinity of the refrigerant inlet pipe, heat is exchanged partway in the outdoor heat exchanger 6, and then the refrigerant is once merged and the gas-liquid separator 9 is arranged downstream thereof. When the upstream side of the gas-liquid separator is the first outdoor heat exchanger 6A and the downstream side is the second outdoor heat exchanger 6B, the refrigerant flowing into the gas-liquid separator 9 is converted into gas and liquid. Separated, the liquid refrigerant is led to the second outdoor heat exchanger 6B, and the gas refrigerant is led to the outlet pipe 10 of the second outdoor heat exchanger 6B by the circuit 12 that bypasses the flow regulating valve 11, and merges. At this time, control is performed to adjust the opening of the flow rate adjusting valve 11 in accordance with the rotational speed of the compressor 1.

  By providing such a route, the following performance improvement effect can be expected. (1) By bypassing a gas refrigerant having a high flow rate, a gas-liquid separator is applied to a normal cycle shown by a solid line as shown in the Mollier diagram of FIG. Cycle form, ie, reduced refrigerant pressure loss during the evaporation process. (2) By combining the refrigerant once in the middle of the outdoor heat exchanger 6 and performing gas-liquid separation, it is possible to optimize the path balance by diverting the refrigerant almost in a liquid state. However, when the rotational speed of the compressor 1 is high, the gas-liquid separation performance is reduced, and the liquid-gas mixed refrigerant bypasses. The two indoor heat exchanger 6B can be used effectively.

  Alternatively, in order to adjust the optimum opening degree of the flow rate adjustment valve 11, for example, the compressor refrigerant discharge temperature sensor 13 is attached, and the flow rate adjustment valve 11 is gradually opened, and the compressor refrigerant discharge temperature is suddenly lowered. It is considered that the liquid refrigerant is also bypassed, and by incorporating the control for closing the opening of the flow rate adjusting valve 11, the gas bypass amount can be optimized and the performance can be improved.

  Further, since the effect of gas-liquid separation cannot be obtained during the cooling operation, the flow rate adjustment valve is closed to prevent the refrigerant from bypassing.

Figure 2 is a second embodiment according to the present invention, to reduce the diameter of d ₂ than the pipe diameter d ₁ of the refrigerant flow path pipe diameter of the second outdoor heat exchanger 6B first outdoor heat exchanger 6A together, the pressure loss ΔP2 when using small diameter tube diameter d ₂ to set the number of refrigerant flow so as to be smaller than the pressure loss ΔP1 of the pipe diameter d ₁ of the first outdoor heat exchanger 6A.

When specifically evaluating with numerical values, for example,
Same piping as the first heat exchanger Diameter d ₁ = 7mm, 2 refrigerant paths, pressure loss ΔP1
Small pipe diameter d ₂ = 5mm, 4 refrigerant paths, pressure loss ΔP2
Approximate the case of the case, the typical pressure loss will be derived by the following formula.

ΔP = (128 μ (l / refrigerant pass number) × (Q / refrigerant pass number)) / (πd ⁴ ) [Pa]
d: Pipe diameter [m]
μ: Viscosity coefficient [Pa · s]
l: Pipe length [m] (→ Depends on the number of passes)
Q: Flow rate [m ³ / s] (→ depends on the number of passes)
In the above formula, if the flow rate Q [m ³ / s], the pipe length l [m], and the viscosity coefficient μ [Pa · s] are fixed values,
ΔP1 = (128 μ (l / 2 × Q / 2)) / (π (7 × 10 ⁻³ ) ⁴ ) [Pa]
ΔP2 = (128 μ (l / 4 × Q / 4)) / (π (5 × 10 ⁻³ ) ⁴ ) [Pa]
ΔP2 / ΔP1 = (1/4 × 1/4) / (1/2 × 1/2) / (5 4/7 4) = 0.96
It becomes. Therefore, since the pressure loss of the four passes of the small diameter pipe can be reduced by about 4% with respect to the two paths of the pipe diameter of the first outdoor heat exchanger, the number of passes of the small diameter pipe in this case should be 4 passes or more. By setting, pressure loss can be reduced. In addition, when a small-diameter pipe is used, an improvement in heat transfer performance in the pipe can be expected by increasing the contact area (wetting edge length) between the liquid refrigerant in the pipe and the pipe wall.

FIG. 3 shows that when gas-liquid separation is applied to the gas-liquid separator 11 (cross-sectional area of the inflow pipe 14) ≈ (cross-sectional area of the gas refrigerant outflow pipe 15a) + (cross-sectional area of the liquid refrigerant outflow pipe 15)
(Cross sectional area of gas refrigerant outflow pipe 15a) <(Cross sectional area of liquid refrigerant outflow pipe 15)
When the flow rate adjusting valve 11 optimizes the outflow rate of the gas refrigerant, the refrigerant flowing out of the refrigerant pipe 15 can be made almost liquid refrigerant, and the performance as an evaporator can be improved. it can. For example, when the diameter of the inflow pipe 14 is φ9.52, the above condition can be satisfied by setting the liquid refrigerant outflow pipe 15 to φ7 and the gas refrigerant pipe 15a to φ6.35.

  FIG. 4 is a view showing a fourth embodiment according to the present invention, in which the second outdoor heat exchange is performed when the refrigerant pipe which has become substantially liquid refrigerant flowing out of the gas-liquid separator 9 is divided into a plurality of flow paths. Depending on the heat exchange rate of each flow path in the vessel 6B, the heat exchanger can be used effectively by making the pipe diameter of each flow path different from each other when diverting to the plurality of flow paths. For example, when the wind speed distribution 16 of the air flowing into the second outdoor heat exchanger 6B is as shown in FIG. 4, the branch pipe outlet diameter 17 of the slow path A and the path D on the air side is narrowed to reduce the wind speed. By making the branch pipe outlet diameter 18 of the fast path B and the path C thick, the refrigerant diversion ratio is adjusted so that the temperature of each flow path is approximately equal in the vicinity of the pipe outlet of the outdoor heat exchanger 6. A heat exchanger can be used effectively.

  FIG. 5 is a diagram showing a fifth embodiment according to the present invention, and heat exchange of each flow path is performed when the refrigerant pipe which is substantially liquid refrigerant flowing out from the gas-liquid separator is divided into a plurality of flow paths. The heat exchanger can be used effectively by adjusting the refrigerant length of each flow path according to the capacity.

  For example, when there is a wind speed distribution 16 of the air flowing into the second outdoor heat exchanger 6B as shown in FIG. 5, the pipe length after the diversion of the path A and the path D having a slow wind speed on the air side is lengthened, and the wind speed distribution is obtained. The path B and path C of the fast path are shortened, and the heat exchange of each flow path of the second outdoor heat exchanger 6B is effective by appropriately adjusting the pipe length from the inlet to the outlet of each path. Can be promoted.

  FIG. 6 is a diagram showing an embodiment according to the present invention, and shows a case where a dehumidifying operation is performed with the cycle configuration of the present invention. In the normal dehumidifying operation, the refrigerant flow passes through the outdoor heat exchanger 6 serving as a condenser and flows into the indoor heat exchanger 3, and the dehumidifying valve 8 provided in the middle of the heat exchanger of the indoor heat exchanger 3. By narrowing down, the heat exchanger before the dehumidifying valve 8 becomes a condenser in the flow direction of the refrigerant, and the heat exchanger after the dehumidifying valve 8 becomes an evaporator. By this method, dehumidifying operation can be performed without lowering the indoor temperature. At this time, the condensed refrigerant accumulates in the outdoor heat exchanger 6, resulting in a refrigerant shortage cycle. Therefore, by opening the flow rate adjustment valve 11 during the dehumidifying operation, the refrigerant can be bypassed without passing through the second outdoor heat exchanger 6B, and the refrigerant shortage can be recovered.

  FIG. 7 shows the experimental results showing the relationship between the inner diameter and the performance (COP improvement ratio) of the gas-liquid separator 9 according to the present invention. In this experiment, the result of measuring the performance with the inner diameter of the gas-liquid separator as a parameter is shown. From the result of this experiment, the inner diameter of the gas-liquid separator 9 is approximately 35 mm or more to improve the performance. Can do. In addition, since the performance is converged when the gas-liquid separator 11 has an inner diameter of about 48 mm, the diameter D of the gas-liquid separator 9 is set to 35 mm ≦ D ≦ φ48 mm without increasing the inner diameter more than necessary. Improvements can be made.

It is explanatory drawing which showed the outline | summary of the whole air conditioner concerning this invention. It is explanatory drawing which showed the Mollier diagram of the air conditioner which concerns on this invention. It is explanatory drawing which showed the implementation method of the air conditioner which concerns on this invention. (Example 2) It is explanatory drawing which showed the implementation method of the air conditioner which concerns on this invention. (Example 3) It is explanatory drawing which showed the implementation method of the air conditioner which concerns on this invention. Example 4 It is explanatory drawing which showed the implementation method of the air conditioner which concerns on this invention. (Example 5) It is explanatory drawing which showed the implementation method of the air conditioner which concerns on this invention. (Example 6) It is explanatory drawing which showed the implementation method of the air conditioner which concerns on this invention. (Example 7)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Indoor heat exchanger 4 Indoor ventilation fan 5 Expansion valve 6 Outdoor heat exchanger 6A 1st outdoor heat exchanger 6B 2nd outdoor heat exchanger 7 Outdoor ventilation fan 8 Dehumidification valve 9 Gas-liquid separator 10 Outlet piping 11 Flow control valve 12 Bypass circuit 13 Compressor discharge refrigerant temperature sensor 14 Inflow piping 15, 15a Outflow piping 16 Wind speed distribution 17 Branch pipe outlet diameter of paths A and D 18 Branch pipe outlet diameter of paths B and C

Claims (7)

An air conditioner that performs cooling, heating, and dehumidifying operations by circulating a refrigerant in a refrigerant circuit formed by connecting a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger with refrigerant piping. In
The indoor heat exchanger includes a dehumidifying valve that depressurizes the refrigerant by constricting the valve in the middle of the refrigerant flow pipe, and sandwiches the dehumidifying valve and is located upstream of the dehumidifying valve in a refrigerant flow direction during cooling operation. The indoor heat exchanger is divided into a first indoor heat exchanger, an indoor heat exchanger downstream of the dehumidifying valve is divided as a second indoor heat exchanger, and the dehumidifying valve depressurizes the first indoor heat exchanger. The condenser is the condenser, the second indoor heat exchanger is the evaporator,
Refrigerant piping from the refrigerant inlet piping to the refrigerant outlet piping of the outdoor heat exchanger after being divided into a plurality of flow paths in the vicinity of the refrigerant piping inlet of the outdoor heat exchanger with respect to the refrigerant flow direction during heating operation The refrigerant is combined in the path, and a gas-liquid separator is provided on the downstream side thereof. The upstream side of the gas-liquid separator is the first outdoor heat exchanger, the downstream side is the second outdoor heat exchanger, and the separated gas refrigerant is A bypass pipe is provided so as to join the refrigerant outlet pipe of the outdoor heat exchanger via the flow rate adjustment valve,
An air conditioner that adjusts an opening degree of the flow rate adjusting valve in accordance with a rotation speed of the compressor.   The pressure loss of the second indoor heat exchanger according to claim 1, wherein the diameter of the refrigerant channel pipe of the second indoor heat exchanger is made smaller than the diameter of the refrigerant channel pipe of the first indoor heat exchanger. The air conditioner is characterized in that the number of diversions of the refrigerant flow path is set so as to be smaller than when the same refrigerant flow path pipe diameter as that of the first indoor heat exchanger is used. In Claim 1 or 2, when gas-liquid separation is made to act in the flow direction of the refrigerant during heating operation, piping connected to the gas-liquid separator,
(Cross sectional area of inflow piping) ≒ (Cross sectional area of gas refrigerant outflow piping) + (Cross sectional area of liquid refrigerant outflow piping)
(Cross sectional area of gas refrigerant outflow pipe) <(Cross sectional area of liquid refrigerant outflow pipe)
An air conditioner comprising a gas-liquid separator that satisfies the following conditions.   4. The wind speed distribution in each refrigerant flow path in the second indoor heat exchanger when the refrigerant that has become liquid refrigerant flowing out of the gas-liquid separator is divided into a plurality of flow paths in any one of claims 1 to 3. In consideration of the above, etc., the air pipe is characterized in that the inlet pipe diameter of each flow path is set to a different diameter so that the heat exchanger outlet temperature of each flow path becomes the same refrigerant temperature. Harmony machine.   4. The heat exchange of each refrigerant flow path in the second outdoor heat exchanger according to any one of claims 1 to 3, when the refrigerant that has become liquid refrigerant flowing out of the gas-liquid separator is divided into a plurality of flow paths. In consideration of capacity, the air conditioner is characterized in that the refrigerant channel pipe length from the inlet to the outlet of each refrigerant channel is set so that the heat exchanger outlet temperature of each channel is equal to the refrigerant temperature. .   6. In any one of Claims 1 thru | or 5, the said flow control valve installed in the said bypass piping path | route of the said gas-liquid separator simultaneously with restrict | squeezing the said dehumidification valve in the same refrigerant | coolant flow direction as a cooling operation in the dehumidification operation | movement. An air conditioner characterized by opening.   7. The air conditioner according to claim 1, wherein the gas-liquid separator has a cylindrical shape and an inner diameter of 35 mm or more.

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