JP2010032106A - Air conditioner - Google Patents

Abstract

【Task】
In an air conditioner that also has a dehumidification valve in the middle of the indoor heat exchanger piping, the refrigerant pressure loss in the piping of the indoor heat exchanger is reduced, the indoor heat exchange performance during cooling operation is improved, and the energy efficient air conditioner I will provide a.
[Solution]
In the air conditioner configured to divert to a plurality of refrigerant flow paths when flowing into the second indoor heat exchanger 10 after passing through the dehumidifying valve 8, the refrigerant flow in the dehumidifying valve 8 outlet refrigerant pipe and the second indoor heat exchanger 10 A gas-liquid separator 11 is provided in the middle of the refrigerant pipe leading to the inlet, and a bypass pipe 14 is provided so that the separated gas refrigerant is merged with the refrigerant outlet pipe of the second indoor heat exchanger via the flow rate adjustment valve 13, and compressed. By adjusting the opening degree of the flow rate adjustment valve 13 according to the rotation speed of the machine 1, the pressure loss of the refrigerant flowing in the indoor heat exchanger 6 is reduced, and the cooling performance is improved.
[Selection] Figure 1

Description

  The present invention relates to an indoor heat exchanger having a mechanism capable of adjusting the temperature of air blown from an indoor unit while dehumidifying by installing both a condenser and an evaporator in the same indoor unit during a dehumidifying operation in a heat pump air conditioner In particular, the present invention relates to an air conditioner including an indoor heat exchanger suitable for improving performance during cooling operation.

  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 with this configuration, cooling operation, heating operation, and dehumidification operation are performed by changing the flow direction of the refrigerant using a refrigerant flow switching valve or the like, and research has been conducted to save energy with respect to each of these operating conditions. It is actively done.

  Effective means for energy saving include increasing the size of indoor heat exchangers, increasing the air volume of indoor fans, reducing refrigerant pressure loss in pipes, etc. Especially for air conditioners with large cooling capacity, refrigerant in pipes A device has been devised to improve the performance without increasing the size of the heat exchanger by reducing the pressure loss.

  By the way, there are several methods for dehumidification by an air conditioner, such as a method of dehumidification by weak cooling operation or a method of dehumidification without lowering the blowing air temperature by installing a heater in the indoor unit and energizing the heater during cooling operation. In addition, a dehumidification valve for decompressing the refrigerant is provided in the middle of the piping of the indoor heat exchanger, and the indoor heat exchanger is divided into a condenser and an evaporator during the dehumidifying operation, so that a heater or the like is not installed. There is a dehumidification method that can adjust the discharge air temperature.

  Focusing on these dehumidification methods, dehumidification methods with a dehumidification valve provided in the middle of indoor heat exchanger piping have increased in recent years as dehumidification methods, and the performance improvement with indoor heat exchanger configurations equipped with this dehumidification valve has increased. A lot of research has been done.

  As an effective means of reducing the pressure loss of the refrigerant in the refrigerant flow pipe, a method of diverting the refrigerant flow path into a plurality of parts and reducing the refrigerant flow velocity in the pipe is effective. It is necessary to devise the flow rate balance of each refrigerant flow path that occurs in the system.

  As a system 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 at the outlet of the heat exchanger, the performance is achieved with a gas-liquid separator in the heat exchanger There are some which improve (for example, refer to patent documents 1). In this patent, a gas-liquid separator is provided in the middle of the refrigerant pipe from the inlet to the outlet of the heat exchanger, and as described above, the gas component is extracted and bypassed to the heat exchanger outlet pipe, so that the performance as an evaporator is obtained. The method to improve is taken.

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 other cases, the gas bypass amount cannot be sufficiently secured, and the flow rate is unbalanced when the refrigerant flow is diverted, so that the performance may be deteriorated.

  In view of this, the present invention has been made in consideration of the problems, and includes a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, an outdoor heat exchanger, and the like, each connected by a refrigerant pipe or the like to form a refrigerant circuit. The air conditioner is capable of cooling, heating and dehumidifying operation by circulating the air, and the indoor heat exchanger has a dehumidifying valve capable of depressurizing the refrigerant by restricting the valve in the middle of the refrigerant flow pipe. 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, the first dehumidifying valve upstream of the first The refrigerant flow arrangement of the indoor heat exchanger is the first indoor heat exchanger. The refrigerant is divided into at least two flow paths before reaching the refrigerant outlet, and the refrigerant merges into one flow path when passing through the dehumidifying valve, and flows into the second indoor heat exchanger after passing through the dehumidifying valve. In the air conditioner that is configured to divert again into a plurality of flow paths, a gas-liquid separator is disposed in the middle of the refrigerant flow pipe that reaches the dehumidification valve outlet refrigerant pipe and the second indoor heat exchanger refrigerant inlet. A bypass pipe is provided so that the separated and separated gas refrigerant is joined to the refrigerant outlet pipe of the second indoor heat exchanger via the flow rate adjustment valve, and the opening degree of the flow rate adjustment valve is adjusted according to the rotational speed of the compressor. The air conditioner is characterized by having control to adjust.

  Further, in claim 2, the refrigerant channel pipe diameter of the second indoor heat exchanger is made smaller than the refrigerant channel pipe diameter of the first indoor heat exchanger, and a small-diameter pipe is used. The number of flow branches of the refrigerant flow path is set so that the pressure loss is smaller than when the same refrigerant flow path pipe diameter as that of the first indoor 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 cooling operation, the pipe connected to the gas-liquid separator is (cross-sectional area of the inflow pipe) ≈ (gas refrigerant) Cross-sectional area of outflow pipe) + (cross-sectional area of liquid refrigerant outflow pipe)
(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.

  In the fourth aspect, in addition to the above-described invention, when the refrigerant, which is substantially liquid refrigerant flowing out from the gas-liquid separator, is divided into a plurality of flow paths, each refrigerant flow path in the second indoor heat exchanger is Considering the heat exchange capacity, that is, the wind speed distribution, etc., the inlet pipe diameter of each flow path is different from each other so that the heat exchanger outlet temperature of each flow path becomes approximately the same refrigerant temperature. It is characterized by setting.

  In 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, the heat exchange capacity of each refrigerant flow path in the second indoor heat exchanger, that is, the wind speed In consideration of the distribution and the like, the length of the refrigerant pipe 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 approximately the same refrigerant temperature.

  According to a sixth aspect of the present invention, the gas-liquid separator has a cylindrical shape, and at least its inner diameter is set to about 35 mm or more.

  As an effect of claim 1 according to the present invention, a compressor, a four-way valve, an indoor heat exchanger, an expansion valve, an outdoor heat exchanger and the like are provided, and each is connected by a refrigerant pipe or the like to form a refrigerant circuit, A dehumidification valve that can perform cooling, heating, and dehumidifying operation by circulating the refrigerant, and the indoor heat exchanger can depressurize the refrigerant by restricting the valve in the middle of the refrigerant flow pipe. And the dehumidifying valve upstream side heat exchanger in the cooling flow direction during cooling operation is a first indoor heat exchanger, the downstream indoor heat exchanger is a second indoor heat exchanger, and so on. Is an air conditioner in which one is a condenser and the other is an evaporator by depressurization by the dehumidifying valve, and the first indoor heat exchange upstream of the dehumidifying valve The refrigerant flow path arrangement of the cooler is a refrigerant outlet of the first indoor heat exchanger When the refrigerant passes through the dehumidification valve, it merges into one flow path and flows into the second indoor heat exchanger after passing through the dehumidification valve. In the air conditioner configured to again divert into a plurality of flow paths, a gas-liquid separator is provided in the middle of the refrigerant pipe reaching the dehumidifying valve outlet refrigerant pipe and the second indoor heat exchanger refrigerant inlet, and the separated gas A bypass pipe is provided so as to join the refrigerant to the refrigerant outlet pipe of the second indoor heat exchanger via the flow rate adjustment valve, and control is provided for adjusting the opening degree of the flow rate adjustment valve in accordance with the rotational speed of the compressor. Thus, when diverting to a plurality of flow paths after passing through the dehumidifying valve, the liquid refrigerant and the gas refrigerant are appropriately separated by the flow rate adjusting valve in the gas-liquid separator installed on the refrigerant downstream side of the dehumidifying valve, and the gas refrigerant is bypassed. Gas-liquid mixing that has occurred It is possible to eliminate the imbalance of refrigerant distribution when diverting to multiple paths in the medium state, and to bypass the gas component that hardly contributes to the heat exchange performance as an evaporator, and to improve the performance as an evaporator it can.

  According to the second aspect of the present invention, the diameter of the refrigerant passage pipe of the second indoor heat exchanger is made smaller than the diameter of the refrigerant passage pipe of the first indoor heat exchanger, and a small diameter pipe is used. By setting the number of diversions of the refrigerant flow path so that the pressure loss in the case of using the same refrigerant flow path pipe diameter as that of the first indoor heat exchanger is reduced, the diameter of the heat exchanger is small. By using the pipe, we can improve the heat transfer performance in the pipe by increasing the wet splash length of the refrigerant in the pipe, and reduce the pressure loss when acting as an evaporator by dividing the pipe into multiple pipes. If the heat exchanger is comprehensively evaluated including the case where the heat exchanger is used as a condenser, the performance of the heat exchanger can be improved.

According to the third aspect of the present invention, when gas-liquid separation is applied in the refrigerant flow direction during cooling operation, the pipe connected to the gas-liquid separator is (cross-sectional area of the inflow pipe) ≈ (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.

  In addition, as an effect of claim 4, when the refrigerant that has become substantially liquid refrigerant flowing out of the gas-liquid separator is divided into a plurality of flow paths, the heat exchange capacity of each refrigerant flow path in the second indoor heat exchanger In other words, considering the wind speed distribution, etc., the inlet pipe diameter of each flow path when diverting to a plurality of flow paths is set to a different diameter so that the heat exchanger outlet temperature of each flow path becomes approximately the same refrigerant temperature. Thus, the flow rate can be adjusted, and the heat exchange rate after the flow can be optimally set.

  According to the fifth 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 indoor heat exchanger is performed. 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 claim 6, 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 restricting the valve in the middle of the refrigerant flow pipe, and in the refrigerant flow direction during cooling operation. The indoor heat exchanger on the upstream side of the dehumidifying valve is divided into two parts with the dehumidifying valve sandwiched between the first indoor heat exchanger, the downstream indoor heat exchanger is called the second indoor heat exchanger, and so on. The refrigerant flow arrangement of the first indoor heat exchanger on the upstream side of the dehumidification valve is an air conditioner in which one side can be a condenser and the other side is an evaporator. There are at least two flow paths before reaching the refrigerant outlet of the exchanger. The air conditioner is configured to flow, and when the refrigerant passes through the dehumidifying valve, it merges into one flow path, and when it flows into the second indoor heat exchanger after passing through the dehumidifying valve, it is divided again into a plurality of flow paths. In the machine, a gas-liquid separator is provided in the middle of the refrigerant pipe reaching the dehumidifying valve outlet refrigerant pipe and the second indoor heat exchanger refrigerant inlet, and the separated gas refrigerant is supplied to the second indoor heat via a flow rate adjusting valve. An indoor heat exchanger was used as an evaporator by providing a bypass pipe so as to merge with the refrigerant outlet pipe of the exchanger and adjusting the opening of the flow rate adjustment valve in accordance with the rotational speed of the compressor. In this case, the heat transfer performance can be improved by appropriately bypassing the gas refrigerant, and the refrigerant distribution performance can be improved by substantially changing the state of the refrigerant when flowing into the second indoor heat exchanger to a liquid refrigerant. To reduce refrigerant pressure loss. Since it is, to achieve a goal of particularly improving the cooling performance.

  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 air_conditionaing | cooling operation, the refrigerant | coolant made into high temperature and high pressure gas in the compressor 1 will flow in into the outdoor heat exchanger 3 via the four-way valve 2, and the outdoor ventilation fan 4 in the outdoor 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 that has become low temperature and low pressure flows into the indoor heat exchanger 6, exchanges heat with the air sent by the indoor blower fan 7, and then returns to the compressor 1 again through the four-way valve 2.

  Here, the indoor heat exchanger 6 is divided into a first indoor heat exchanger 9 and a second indoor heat exchanger 10 by a dehumidifying valve 8 that can depressurize the refrigerant during the dehumidifying operation. By narrowing the dehumidifying valve 8, the first indoor heat exchanger 9 upstream of the refrigerant flow direction across the dehumidifying valve 8 becomes a condenser, and the second indoor heat exchanger 10 downstream is an evaporator. It becomes.

  At this time, in the indoor heat exchanger 6, the gas-liquid separator 11 is installed on the refrigerant downstream side of the dehumidification valve 8, and the second indoor heat exchanger 10 located on the refrigerant downstream side of the gas-liquid separator 11 is connected to the refrigerant pipe. In addition, a circuit 14 for bypassing the outlet pipe 12 of the indoor heat exchanger 6 from the gas-liquid separator 11 via the flow rate adjustment valve 13 is installed.

  In the air conditioner having such a configuration, the refrigerant flows into the gas-liquid separator 11 after passing through the dehumidifying valve 8 by adjusting the opening degree of the flow rate adjusting valve according to the number of rotations of the compressor during the cooling operation, and is liquid refrigerant inside. And gas refrigerant. After that, the refrigerant that is in a substantially liquid state branches in the path A direction and the path B direction in the vicinity of the inlet of the second indoor heat exchanger 10, flows into the second indoor heat exchanger 10, and performs outlet exchange while performing heat exchange. To. On the other hand, the gas refrigerant separated by the gas-liquid separator 11 is led to the indoor heat exchanger outlet pipe 12 via the flow rate adjusting valve 13 without flowing into the second indoor heat exchanger 10 by the bypass circuit 14.

  By providing such a path, the following performance improvement effect can be obtained. (1) Performance improvement by flowing liquid refrigerant into the second indoor heat exchanger 10 instead of gas refrigerant having low heat exchange performance. (2) By bypassing a gas refrigerant having a high flow rate, a cycle configuration as shown by a broken line by operating a gas-liquid separator on a normal cycle shown by a solid line as shown in the Mollier diagram of FIG. That is, reduction of refrigerant pressure loss in the evaporation process. (3) It is possible to optimize the path balance of the refrigerant branched in the second indoor heat exchanger 10. However, when the rotational speed of the compressor 1 is high, the gas-liquid separation performance is reduced and the liquid-gas mixed refrigerant is bypassed. Therefore, by setting the flow rate adjustment valve 13 to be closed, the performance is not reduced. The two-room heat exchanger 10 can be used effectively. Alternatively, in order to adjust the optimum opening degree of the flow rate adjusting valve 13, for example, the compressor refrigerant discharge temperature sensor 15 is attached and the flow rate adjusting valve 13 is gradually opened, and the compressor refrigerant discharge temperature is suddenly lowered. It is assumed that the liquid refrigerant is also bypassed, and by incorporating control for closing the opening of the flow rate adjusting valve 13, 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 heating operation, the flow rate adjustment valve is closed to prevent the refrigerant from bypassing.

FIG. 3 shows a second embodiment according to the present invention, wherein the refrigerant passage pipe diameter of the second indoor heat exchanger 10 is made smaller than the pipe diameter d ₁ of the first heat exchanger 9 and is d _2. The refrigerant flow number is set so that the pressure loss ΔP2 when the small diameter pipe diameter d ₂ is used is smaller than the pressure loss ΔP1 of the conventional pipe d ₁ .

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 = (128μ (l / refrigerant pass number) × (Q / number refrigerant path)) / (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 4-pass of the small-diameter pipe can be reduced by about 4% with respect to the 2-path of the first heat exchanger pipe diameter, the number of passes of the small-diameter pipe in this case is set to 4 or more. By doing so, pressure loss can be reduced. Moreover, when a small diameter pipe | tube is used, the heat transfer performance improvement in piping can be anticipated by the increase in the contact area (wetting edge length) of the liquid refrigerant in a pipe | tube, and a pipe wall.

FIG. 4 shows the gas-liquid separator 11 when gas-liquid separation is applied (cross-sectional area of the inflow pipe 18) ≈ (cross-sectional area of the gas refrigerant outflow pipe 19a) + (cross-sectional area of the liquid refrigerant outflow pipe 19)
(Cross sectional area of gas refrigerant outflow pipe 19a) <(Cross sectional area of liquid refrigerant outflow pipe 19)
When the flow rate adjustment valve 13 optimizes the outflow rate of the gas refrigerant, the refrigerant flowing out from the refrigerant pipe 19 can be substantially liquid refrigerant, and the performance as an evaporator can be improved. it can. For example, when the diameter of the inflow pipe 18 is φ9.52, the above condition can be satisfied by setting the liquid refrigerant outflow pipe 19 to φ7 and the gas refrigerant pipe 19a to φ6.35.

  FIG. 4 is a diagram showing a fourth embodiment according to the present invention. In the second indoor heat exchanger 10 when the refrigerant pipe that has become substantially liquid refrigerant flowing out from the gas-liquid separator is divided into multiple paths. The heat exchanger can be used effectively by adjusting the pipe diameter of each path when diverting into multiple paths according to the heat exchange rate of each path. For example, when the wind speed distribution 20 of the air flowing into the second indoor heat exchanger 10 is as shown in FIG. 4, the branch pipe outlet diameter 21 of the path A and path D where the wind speed is slow on the air side is narrowed, and the air side By increasing the branch pipe outlet diameter 22 of the paths B and C where the wind speed is fast, the refrigerant diversion ratio is adjusted, and in the vicinity of the pipe outlet 12 of the indoor heat exchanger 6, the temperature is set to be approximately equal for each path. A heat exchanger can be used effectively.

  FIG. 6 is a view showing a fifth embodiment according to the present invention. In the second indoor heat exchanger 10 when the refrigerant pipe which is substantially liquid refrigerant flowing out from the gas-liquid separator is divided into multiple paths. The heat exchanger can be used effectively by adjusting the length of the refrigerant flow pipe of each path according to the heat exchange rate of each path.

  For example, when there is a wind speed distribution 20 of the air flowing into the second indoor heat exchanger 10 as shown in FIG. 6, the pipe length after the diversion of the path A and the path D where the wind speed is slow on the air side is lengthened. The heat exchange of each path of the indoor heat exchanger 10 is effectively promoted by shortening the pipe length of the fast path B and path C and appropriately adjusting the pipe length from the inlet to the outlet of each path. be able to.

  FIG. 7 shows the experimental results showing the relationship between the inner diameter and the performance (COP improvement ratio) of the gas-liquid separator 11 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 11 is set to approximately 35 mm or more to improve the performance. Can do. Further, since the performance is converged when the gas-liquid separator 11 has an inner diameter of about φ48 mm, the diameter D of the gas-liquid separator 11 is set to φ35 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)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Outdoor heat exchanger 4 Outdoor ventilation fan 5 Expansion valve 6 Indoor heat exchanger 7 Indoor ventilation fan 8 Dehumidification valve 9 1st indoor heat exchanger 10 2nd indoor heat exchanger 11 Gas-liquid separator 12 Outlet pipe 13 Flow rate adjusting valve 14 Bypass circuit 15 Compressor discharge refrigerant temperature sensor 16 Conventional pipe 17 Small diameter pipe 18 Inflow pipe 19 Liquid refrigerant outflow pipe 19a Gas bypass outflow pipe 20 Wind speed distribution 21 Branch pipe outlet diameter 22 of paths A and D Branch pipe outlet diameter for paths B and C

Claims (6)

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,
The refrigerant flow path of the first indoor heat exchanger is divided into a plurality of flow paths until reaching the refrigerant outlet of the first indoor heat exchanger, and merges into one flow path when the refrigerant passes through the dehumidification valve. And after passing through the dehumidifying valve, when it flows into the second indoor heat exchanger, it is divided into a plurality of flow paths again,
A gas-liquid separator is provided in the middle of the refrigerant flow pipe leading to the dehumidifying valve outlet refrigerant pipe and the second indoor heat exchanger refrigerant inlet, and the separated gas refrigerant is supplied to the second indoor heat exchanger via a flow rate adjusting valve. Provide bypass piping to join the refrigerant outlet piping,
An air conditioner that adjusts an opening degree of the flow rate adjusting valve in accordance with a rotation speed of the compressor. 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,
The refrigerant passage pipe diameter of the second indoor heat exchanger is made smaller than the refrigerant passage pipe diameter of the first indoor heat exchanger, and the pressure loss of the second indoor heat exchanger causes the first indoor heat exchanger to An air conditioner characterized in that the number of flow branches of the refrigerant flow path is set to be smaller than that when the same refrigerant flow path pipe diameter as that of the heat exchanger is used. In Claim 1 or 2, when gas-liquid separation is applied in the flow direction of the refrigerant during cooling operation, a pipe connected to the gas-liquid separator is
(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.   The heat exchange of each refrigerant flow path in the second indoor heat exchanger according to any one of claims 1 to 4, 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. The air conditioner according to claim 1, wherein the gas-liquid separator has a cylindrical shape, and at least an inner diameter thereof is set to 35 mm or more.

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