JPH07120104A - Air conditioner - Google Patents

Abstract

PURPOSE:To reduce a pressure pulsation generated by flow of refrigerant in an indoor unit and a tube vibration generated due to the pressure pulsation and to further reduce pressure pulsation and a tube vibration to be propagated to a heat exchanger which tend to promote vibration, noise. CONSTITUTION:An expansion valve 3 contained in an indoor unit 21 is so disposed that a first heat exchanger side tube of the valve becomes horizontal and a distributor side tube becomes vertical, the distributor 4 is so disposed that a tube 12 of the valve side becomes vertical, and the first exchanger side tube of the valve is connected to the tube 12 by an L-shaped tube 11 so disposed that a tube axis of one end coincides with an axis of the first exchanger side tube of the value and a tube axis of the other end becomes perpendicular to that of the tube 12. A corner of the tube 11 is rounded of 30mm of a radius, and an orifice for controlling a dust-proofing net and a flowing state of gas- liquid two-phase flow is contained in the tube 12. Thus, refrigerant flowing sound in the indoor unit is reduced, and extraordinary sound such as intermittent flowing sound, etc., is also reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner equipped with an expansion valve and a distributor connected to the expansion valve, and particularly, the refrigerant pipe of an indoor unit is made compact and the refrigerant flow noise is reduced. Regarding air conditioners.

[0002]

2. Description of the Related Art In an air conditioner that uses an expansion valve as a refrigerant flow rate control and decompression expansion mechanism, a refrigerant flow noise generated from an expansion valve, a refrigerant ejection noise from a capillary tube and heat transfer tube vibration, and heat exchange. As a method of reducing the flow noise of the refrigerant generated from the container, Japanese Patent Laid-Open Nos. 4-186071, 57-198967 and 60-2 are available.
There are those disclosed in 07873 and Japanese Utility Model Laid-Open No. 57-160027.

According to the method disclosed in Japanese Patent Laid-Open Publication No. 4-186071, when the flow on the upstream side of the expansion valve is a gas-liquid two-phase flow, the gas-liquid two-phase flow when the refrigerant passes through the throttle of the expansion valve. The refrigerant flow noise generated due to the flow flow pattern of the flow is arranged so that the pipe axis of the inlet pipe of the expansion valve is orthogonal to the gravity direction to improve the flow pattern, thereby reducing the refrigerant flow noise. There is.

According to the one disclosed in Japanese Patent Laid-Open No. 57-198967, the refrigerant passage area from the capillary tube constituting the refrigeration cycle to the connection with the heat exchanger heat transfer tube is gradually increased. It is configured to reduce jet noise, fluid noise, and heat transfer tube vibration.

In the one disclosed in Japanese Patent Laid-Open No. 60-207873, a pipe having a vibration-proof material such as a butyl sheet or putty is provided on the inlet side of the expansion valve to eliminate the refrigerant flow noise. ing.

In the one disclosed in Japanese Utility Model Laid-Open No. 57-160027, the noise of the refrigerant flowing from the U-shaped pipes coming out from both sides of the heat exchanger is shut off to reduce the noise of the refrigerant flow. .

[0007]

The above-mentioned prior art is mainly concerned with the reduction of refrigerant flow noise and pipe vibration generated from a pressure reducing mechanism such as an expansion valve or a capillary tube, and pressure pulsation of the refrigerant flow is generated in the pressure reducing mechanism. However, it is not considered as a problem of the entire piping system in which this propagates as a pressure wave in the pipe or is transmitted to the heat exchanger as pipe vibration, and the heat exchanger expands the refrigerant flowing sound as a speaker. In particular, the arrangement of the expansion valve in the above-mentioned related art is to deal with the refrigerant flow noise caused by the flow pattern of the refrigerant gas-liquid two-phase flow flowing into the expansion valve, and the refrigerant gas-liquid two-phase flowing out from the expansion valve. No consideration is given to refrigerant flow noise due to flow. Regarding the stepwise expansion of the refrigerant passage area on the downstream side of the capillary tube, consideration is given to the case where the refrigerant flow flowing out of the capillary tube has a sonic velocity, and piping other than the capillary tube is not considered. Further, regarding the use of a pipe provided with a vibration damping material at the expansion valve inlet, no consideration is given to the expansion valve outlet side.
Further, regarding the sound insulation of the refrigerant flowing sound generated from the U-shaped pipes coming out from both sides of the heat exchanger, it is considered that the pressure pulsation and the pipe vibration propagating to the heat exchanger are basically cut off. Not not.

In an indoor unit having a small space for arranging piping, optimization of the piping system is considered in order to reduce the refrigerant flow noise generated from the entire piping system including the pressure reducing mechanism such as the expansion valve and the heat exchanger. There is a need. It is the indoor unit that the refrigerant flow noise is particularly problematic in the noise of the air conditioner. The piping components arranged in the indoor unit include an expansion valve, a distributor,
There is a second heat exchanger, a pipe connecting these, a dustproof net built in the pipe to prevent clogging of the expansion valve throttle, and a flow correction orifice also built in the pipe. In addition, the piping space in the machine room of the indoor unit in which these piping systems are housed is generally narrow, and there is no choice but to have a piping configuration with many bends. Therefore, the flow changes due to the influence of bending, etc. As a result, the pressure pulsation of the fluid is generated and promoted, and the pipe vibration is induced, which appears as a refrigerant flow noise. Further, as the air conditioner saves refrigerant, the refrigerant flows into the expansion valve installed in the indoor unit in a gas-liquid two-phase flow state. The gas-liquid two-phase flow is an unsteady flow itself and has pressure pulsation. Therefore, it is necessary to reduce the pressure pulsation in the piping system after the expansion valve. Therefore, optimizing the piping configuration leads to a reduction in refrigerant flow noise. In addition, the optimized piping configuration must also satisfy the cycle performance.

It is an object of the present invention to reduce refrigerant flow noise generated from a piping system of an indoor unit and eliminate abnormal noise.

[0010]

In order to achieve the above object, the first air conditioner of the present invention comprises at least a compressor,
A compressor, a first heat exchanger, an expansion valve, a distributor, a second heat exchanger, and a compressor again formed by connecting the first heat exchanger, the expansion valve, the distributor, and the second heat exchanger with piping. In the air conditioner including a refrigeration cycle in which the refrigerant is circulated in this order, and the refrigerant condensed and liquefied in the first heat exchanger is evaporated in the second heat exchanger for cooling, the first heat exchange from the compressor Expansion unit connected to the expansion valve inlet in the piping extending from the expansion valve to the second heat exchanger in the indoor unit. The expansion valve is arranged so that the valve first heat exchanger side piping axis is substantially orthogonal to the gravity direction, and the expansion valve distributor side piping axis connected to the expansion valve outlet is substantially parallel to the gravity direction, It is also connected to the distributor inlet on the refrigerant pipe from the expansion valve to the second heat exchanger. A pipe containing an orifice is arranged so that its pipe axis substantially coincides with the direction of gravity, and at least one pipe having the bend is provided between the pipe containing the orifice and the expansion valve distributor-side pipe connected to the expansion valve outlet. In addition, the distributor and the second heat exchanger are connected by a plurality of pipes.

In order to achieve the above object, the second air conditioner of the present invention has at least a compressor, a four-way valve, a first heat exchanger, an expansion valve, a distributor, and a second heat exchanger as pipes. The refrigerant is circulated in a forward cycle in which the refrigerant is sequentially passed from the compressor through the four-way valve, the first heat exchanger, the expansion valve, the distributor, the second heat exchanger, and then returned to the compressor via the four-way valve. When letting
When the first heat exchanger functions as a condenser and the second heat exchanger functions as an evaporator, and when the refrigerant is circulated in the reverse cycle of the forward cycle and the reverse direction, the second heat exchanger serves as the condenser and the first heat exchanger. In an air conditioner configured by a heating / cooling cycle in which a heat exchanger functions as an evaporator, a compressor to a first heat exchanger are arranged in an outdoor unit, and an expansion valve to a second heat exchanger are arranged.
In the pipe extending from the expansion valve to the second heat exchanger, the heat exchanger is arranged in the indoor unit, and the pipe axis of the expansion valve first heat exchanger side pipe connected to the second heat exchanger side of the expansion valve. Is arranged substantially perpendicular to the direction of gravity, and the expansion valve is arranged such that the pipe axis of the expansion valve distributor side pipe connected to the distributor side of the expansion valve is substantially parallel to the direction of gravity. Arrange the piping connected with the expansion valve side of the orifice and the dustproof net so that the piping axis is almost parallel to the direction of gravity,
It is characterized in that the orifice / dustproof net built-in pipe and the expansion valve distributor side pipe are connected by at least one bent pipe, and the distributor and the second heat exchanger are connected by a plurality of pipes.

In order to achieve the above object, the third air conditioner of the present invention has at least a compressor, a first heat exchanger, a pressure reducing mechanism, an expansion valve, a distributor, and a second heat exchanger as pipes. Are connected and formed by a compressor, a first heat exchanger, a pressure reducing mechanism,
In an air conditioner that constitutes a refrigeration cycle in which a refrigerant is circulated in the order of an expansion valve, a distributor, a second heat exchanger, and a compressor again, the compressor to the decompression mechanism are arranged in an outdoor unit, and the expansion valve to the second The heat exchanger is arranged in the indoor unit, and in the pipe from the expansion valve of the indoor unit to the second heat exchanger, the pipe axis of the expansion valve first heat exchanger side pipe connected to the expansion valve upstream side is gravity. The expansion valve so that the pipe axis of the expansion valve distributor side pipe connected to the downstream side of the expansion valve is substantially parallel to the direction of gravity, and the second heat exchange with the distributor. It is characterized in that it is connected to the container with a plurality of pipes.

In order to achieve the above object, the fourth air conditioner of the present invention includes at least a compressor, a four-way valve, a first heat exchanger, a pressure reducing mechanism, an expansion valve, a distributor, and a second heat exchange. The compressor is connected by piping, and the refrigerant is sequentially passed from the compressor through the four-way valve, the first heat exchanger, the pressure reducing mechanism, the expansion valve, the distributor, the second heat exchanger, and again through the four-way valve. When the first heat exchanger functions as a condenser and the second heat exchanger functions as an evaporator when the refrigerant is circulated in the forward cycle, the second heat exchanger is used when the refrigerant is circulated in the reverse cycle in the reverse direction of the forward cycle. In an air conditioner that constitutes a cooling and heating cycle in which the exchanger functions as a condenser and the first heat exchanger functions as an evaporator, the compressor to the decompression mechanism are arranged in the outdoor unit, and the expansion valve to the second heat exchanger. Is placed in the indoor unit, and the In the pipe leading to the heat exchanger, the expansion valve is connected to the pressure reducing mechanism side of the expansion valve so that the pipe axis of the expansion valve first heat exchanger side pipe is substantially perpendicular to the gravity direction and to the distributor side of the expansion valve. The expansion valve is arranged so that the pipe axis of the expansion valve distributor side pipe is substantially parallel to the direction of gravity, and is connected to the distributor provided on the refrigerant pipe from the expansion valve to the second heat exchanger. The orifice and the dustproof net are installed so that the pipe axis is almost parallel to the direction of gravity, and the orifice / dustproof built-in pipe and the expansion valve distributor side pipe are at least one bent pipe. connection,
Further, the distributor and the second heat exchanger are connected by a plurality of pipes.

In order to achieve the above object, another air conditioner of the present invention is the air conditioner according to any one of the first to fourth air conditioners, wherein the pipe axis connected to the distributor side of the expansion valve is gravity. Direction of the expansion valve distributor side pipe that is substantially parallel to the direction and the pipe that connects the expansion valve side of the distributor and the pipe axis that is substantially parallel to the gravity direction It is characterized in that it is at least 30 mm.

In order to achieve the above object, another air conditioner of the present invention is the air conditioner of the first to fourth aspects, wherein the pipe shaft connected to the distributor side of the expansion valve is gravity. The pipe connecting the expansion valve distributor side pipe that is substantially parallel to the direction and the pipe whose pipe axis connected to the expansion valve side of the distributor is substantially parallel to the direction of gravity is a bent pipe that has at least two bends. Is characterized by.

In order to achieve the above object, another air conditioner of the present invention is the air conditioner according to any one of the first to fourth air conditioners, wherein the pipe shaft connected to the distributor side of the expansion valve is gravity. The pipe connecting the expansion valve distributor side pipe substantially parallel to the direction and the pipe whose pipe axis connected to the expansion valve side of the distributor is substantially parallel to the gravity direction is a semi-circular pipe.

In order to achieve the above object, another air conditioner of the present invention is the air conditioner according to any one of the first to fourth air conditioners, wherein the pipe shaft connected to the distributor side of the expansion valve is gravity. Direction of the expansion valve distributor side pipe and the pipe connected to the expansion valve side of the distributor pipe axis is substantially parallel to the direction of gravity, the diameter of the pipe is the expansion valve distributor side pipe diameter It is characterized by being the same as.

In order to achieve the above object, another air conditioner of the present invention is, in each of the first to fourth air conditioners, a plurality of pipes connecting the distributor and the second heat exchanger. The inner diameter of is gradually increased from the distributor toward the second heat exchanger.

In order to achieve the above object, another air conditioner of the present invention is the air conditioner described in the above paragraph,
The inner diameters of the plurality of pipes connecting the distributor and the second heat exchanger are A1, the cross-sectional area of the pipe near the distributor is A1, the cross-sectional area of the pipe near the second heat exchanger is A3, and the distributor and the second heat exchanger. The cross-sectional area ratio is 3.5 <A2 / A, where A2 is the cross-sectional area of the middle pipe
It is characterized in that it is expanded stepwise such that 1 <4.5 and 1.9 <A3 / A2 <2.2.

In order to achieve the above object, another air conditioner of the present invention is a plurality of pipes for connecting a distributor and a second heat exchanger in each of the first to fourth air conditioners. The inner diameter of is smoothly and steplessly expanded from the distributor toward the second heat exchanger.

In order to achieve the above-mentioned object, another air conditioner of the present invention has a plurality of pipes connecting the distributor and the second heat exchanger in each of the first to fourth air conditioners. ,
A feature is that a flexible member is used.

In order to achieve the above object, another air conditioner of the present invention is the air conditioner of the first to fourth aspects, wherein a damping material is provided in the piping of the inlet and outlet of the second heat exchanger. It is characterized by being attached.

In order to achieve the above object, another air conditioner of the present invention is the air conditioner according to any one of the first to fourth air conditioners, wherein the expansion valve inside the indoor unit is distributed from the pipe on the outdoor unit side. The feature is that damping material is attached to the piping up to the vessel and the piping components.

[0024]

In the air conditioner configured as described above,
In the pipe from the expansion valve of the indoor unit to the second heat exchanger,
By arranging the pipe axis of the expansion valve first heat exchanger side pipe of the expansion valve on the first heat exchanger side (outdoor unit side) so as to be substantially orthogonal to the gravity direction, the refrigerant at the expansion valve inlet can be saved in the refrigerant saving cycle. Even in the state of gas-liquid two-phase flow, since the refrigerant flow is horizontal, the refrigerant flow mode is a laminar flow or a wavy flow.
In the laminar flow and the wavy flow, since the gas phase and the liquid phase are continuous flows, respectively, the intermittent flow noise, which is the largest noise among the refrigerant flow noises, is reduced. Further, the occurrence of pressure pulsation in the expansion valve throttle portion due to the flow mode is suppressed.

Further, the refrigerant jet flow passing through the throttle of the expansion valve becomes a gas-liquid two-phase flow, and this gas-liquid two-phase flow goes straight in the expansion valve distributor side pipe arranged with its axis aligned with the direction of gravity. Since it flows downward, the flow is not disturbed, and pressure pulsation and vibration of the pipe at this stage can be avoided.
The gas-liquid two-phase flow, after flowing down in the expansion valve distributor side pipe, collides with the inner wall of the connecting pipe without decelerating and changes the flow direction. Therefore, as the flow rate increases and the flow velocity increases, the momentum increases and the impact force increases. Therefore, increasing the inner diameter of the connecting pipe at least to the same extent as the inner diameter of the expansion valve distributor side pipe slows down the flow velocity, and increasing the radius of curvature of the bent portion of the connecting pipe reduces abrupt changes in the flow direction. Furthermore, by matching the inner diameter of the expansion valve distributor side pipe with the inner diameter of the connecting pipe, the fluctuation of the flow due to the change of the cross-sectional area is reduced. As a result, the unstable flow of the gas-liquid two-phase flow can be suppressed, and the occurrence of pressure pulsation can be reduced.

Further, an orifice for controlling the flow mode of the gas-liquid two-phase refrigerant flowing into the distributor and a dustproof net for preventing clogging are built in the same pipe, and this pipe is connected to the pipe. It is installed on the expansion valve side of the distributor so that the axis is almost in line with the direction of gravity, and this pipe and the expansion valve distributor side pipe whose axis is almost in line with the direction of gravity are pipes with one bend. By connecting, the piping configuration is simplified and made compact. Further, since there is only one curved portion, it is possible to minimize the change in the flow state due to the change from the vertical flow to the horizontal flow, and the flow state of the refrigerant flow is improved. In addition, since the connection pipe with one bend is used, it becomes orthogonal to the orifice / dust protection net built-in pipe, and the refrigerant flow flowing in the connection pipe collides with the inner wall of the orifice / dust protection net built-in pipe. Become. However, the flow velocity increased when passing through the throttle of the expansion valve is also decelerated while flowing in the connecting pipe and the flow is stabilized, so there is no particular problem in terms of generation and promotion of pressure pulsation, and conversely a collision occurs. The gas phase and the liquid phase separated by the above are mixed to form a homogeneous flow, so that the distribution performance can be improved.

Also, although reduced, pipe pulsation occurs due to the presence of pressure pulsation. When this pipe vibration propagates to the second heat exchanger, resonance occurs and noise is generated from the entire second heat exchanger. However, the vibration damping material attached to the pipes before and after the expansion valve reduces the pipe vibration. , Also, by the damping material attached to the inlet and outlet piping of the heat exchanger,
The transmission of piping vibration to the heat exchanger is blocked.

As a result, the generation and promotion of pressure pulsation due to the refrigerant gas-liquid two-phase flow generated in the pipe from the expansion valve installed in the indoor unit to the second heat exchanger and in the heat transfer pipe is suppressed, Further, the pressure pulsation due to the gas-liquid two-phase flow on the upstream side of the expansion valve is also reduced, so that the resonance in the second heat exchanger is also suppressed. Further, the pipe vibration induced by the pressure pulsation is reduced, and the vibration propagation to the second heat exchanger is blocked, so that the resonance of the second heat exchanger is avoided. Therefore,
The refrigerant flow noise generated by the pressure pulsation of the refrigerant flow and the pipe vibration is reduced, and the generation of abnormal noise such as intermittent flow noise is suppressed.

[0029]

The present invention considers the pressure pulsation due to the flow pattern on the upstream side (outdoor unit side) of the expansion valve, while considering the flow of the fluid in the piping system from the expansion valve to the second heat exchanger. Based on the experimental knowledge obtained through the improvement, the generation and promotion of pressure pulsation of the refrigerant flow in the pipe is suppressed, the pipe vibration is reduced, and the pressure pulsation of the fluid propagating to the second heat exchanger is reduced. At the same time, the above object is achieved by blocking the vibration of the pipe.

Embodiments of an air conditioner according to the present invention will be described below with reference to the drawings. 1 to 5 are schematic diagrams showing a cycle configuration and a piping configuration of an air conditioner according to an embodiment of the present invention.

FIG. 1 is a diagram showing a structure of a cooling air conditioner according to a first embodiment of the present invention and a flow of a refrigerant thereof.
The illustrated air conditioner includes a compressor 1 for compressing refrigerant vapor,
A first heat exchanger (hereinafter referred to as a condenser) 2 connected to the outlet side of the compressor 1 by a pipe 15, an expansion valve 3 connected by a pipe 16 to the condenser 2, and an expansion of the expansion valve 3. A distributor 4 connected to the valve distributor side pipe by a connection pipe 11 and a pipe 12; a second heat exchanger (hereinafter referred to as an evaporator) 5 connected to the distributor 4 by a plurality of distribution pipes 14; A pipe 19 connecting the evaporator 5 and the suction side of the compressor 1, and an outdoor fan 9 and an indoor fan 10 for cooling the condenser 2 and the evaporator 5, respectively.
It is configured to include and. Further, the air conditioner of the present embodiment is separated into an outdoor unit 20 and an indoor unit 21, the compressor 1, the condenser 2 and the outdoor fan 9 are housed in the outdoor unit 20, and the indoor unit 21 is , Expansion valve 3, distributor 4, evaporator 5, and indoor fan 10 are housed. The evaporator 5 includes a plurality of heat transfer tubes each having an independent flow path, and each heat transfer tube is connected to the pipe 19 on the outlet side, and the heat exchange tube is provided on the inlet side separately for each heat transfer tube. Each of the plurality of distribution pipes 14 is connected via a container inlet pipe 30.

The refrigerant in the air conditioner is compressed by the compressor 1 to become high-temperature and high-pressure refrigerant vapor, cooled by the condenser 2 to be condensed and liquefied, expanded by the expansion valve 3 and expanded at a temperature lower than the room air temperature. The low-pressure refrigerant is in a gas-liquid two-phase state, takes heat from the indoor air in the evaporator 5 to evaporate, and circulates in the cycle of returning to the compressor 1 again. As shown in FIG. 1, as the piping components of the indoor unit, an expansion valve 3, an L-shaped connecting pipe (hereinafter referred to as L-shaped pipe) 11, an orifice 27 for controlling the flow mode of gas-liquid two-phase flow, and Piping 1 with built-in dustproof net 26
2, a distributor 4 that distributes the refrigerant to a plurality of heat transfer tubes of the evaporator 5, a plurality of distribution pipes 14 through which the distributed refrigerant passes, an evaporator 5
There is a second heat exchanger that is

FIG. 2 is a diagram showing the piping structure from the expansion valve to the distributor in the indoor unit. The expansion valve 3 is the expansion valve body 2
2 so that the pipe axis of the expansion valve first heat exchanger side pipe 23 that is connected to 2 is substantially orthogonal to the gravity direction, and the pipe axis of the expansion valve distributor side pipe 24 that is connected to the expansion valve main body 22 is It is placed so that it is almost parallel to the direction of gravity. The straight part length of the expansion valve first heat exchanger side pipe 23 in this embodiment is about 150 mm. Further, a pipe 25 having a built-in dustproof net 26 connected to the expansion valve first heat exchanger side pipe 23
Also, the pipe axis is arranged so as to be substantially orthogonal to the direction of gravity, that is, aligned with the axis of the expansion valve first heat exchanger side pipe 23. As a result, the refrigerant flows on the inflow side of the expansion valve as a horizontal flow not only when the refrigerant state is a single-phase flow but also when it is a gas-liquid two-phase flow. Since the laminar flow or the corrugated flow, which is the generated flow, becomes the main flow, it is possible to prevent the generation of the abnormal noise of the refrigerant due to the flow pattern such as the plug flow.

On the other hand, since the axis of the expansion valve distributor side pipe 24 forming the flow path of the refrigerant flowing out from the expansion valve is parallel to the direction of gravity, and the refrigerant flows out in the direction of gravity, the expansion valve The refrigerant flow that has passed through the restriction becomes a jet flow that does not impair the flow. In addition, the axis of the cylindrical distributor 4 that distributes the refrigerant to each path of the heat transfer tube of the second heat exchanger, the orifice 27 for controlling the flow mode of the refrigerant flowing into the distributor, and the dustproof net 26 are incorporated. The axis of the pipe 12 is on the same line and is substantially parallel to the direction of gravity, and there is no change in shape such as bending, and it has a shape that suppresses the occurrence of pressure pulsation as much as possible against changes in the flow of the refrigerant. . Further, since the orifice 27 and the dustproof net 26 are put together in the same pipe, downsizing of the pipe is promoted.

The connecting pipe connecting the lower end of the expansion valve distributor side pipe 24 and the lower part of the pipe 12 has one axis aligned with the axis of the expansion valve distributor side pipe 24 and the other axis. L-shaped pipe 11 orthogonal to the axis of is used,
There is only one change in shape due to bending. In this embodiment, the vertical distance between the axis of the expansion valve first heat exchanger side pipe 23 and the horizontal axis of the L-shaped pipe 11 is 70 to 80 mm, and the horizontal axis of the L-shaped pipe 11 and the distributor. The vertical distance of the lower end was about 80 mm. The corner of the L-shaped pipe 11 has a rounded bend, and the radius of curvature of the bend is 30 mm.
Has become. The expansion valve main body 22 is attached to the wall surface of this bent portion.
The refrigerant jets passing through the inner throttle directly collide with each other. At this time, the velocity distribution of the jet is in the process of development, and the center of the jet has a protruding velocity distribution. Further, the refrigerant that has passed through the throttle has a gas-liquid two-phase flow, but the central part of the jet flow is a liquid-rich flow, and as a result, a flow with a large momentum collides with the wall surface. This collision causes the generation of pressure pulsation, and also promotes the pressure pulsation.

As a solution to this, the radius of curvature R of the bent portion is
And a method of reducing the flow velocity in the pipe. The radius of curvature R of the bent portion may be 30 mm or more when the inner diameter of the pipe is about 11 mm. At the connecting portion between the L-shaped pipe 11 and the pipe 12, the refrigerant collides with the inner wall of the pipe 12 and changes the flow direction by 90 degrees, but at this time, the flow velocity distribution has developed and has a protruding velocity distribution. Is not
Moreover, the flow velocity is decelerated due to the pressure loss. Therefore, the impact of the collision is small. Further, since the flows separated into the gas phase and the liquid phase are mixed in the horizontal tube due to the collision, the distribution performance of the refrigerant in the distributor can be improved. Therefore, the pipe shape shown in FIG. 2 suppresses the generation and promotion of pressure pulsation in the pipe,
In addition, pipe vibration is reduced, and as a result, refrigerant flow noise is reduced.

FIG. 3 is a diagram showing the structure of an air conditioner for both heating and cooling according to a second embodiment of the present invention and the flow of the refrigerant during the cooling operation. The configuration of the air conditioner is different from that of the cooling air conditioner of FIG. 1 in that the pipe 19 and the pipe 15 are connected via the four-way valve 8, and the suction port of the compressor 1 is connected to the other connection port of the four-way valve 8. That is, the discharge port is connected. Since other configurations are the same as those in FIG. 1, the elements having the same functions are designated by the same reference numerals as those in FIG. 1, and the description thereof is omitted. The refrigerant discharged from the compressor 1 by switching the four-way valve is
It is configured to flow to the pipe or to the pipe 19. In the present embodiment, the first heat exchanger 2 is
Used as a condenser during cooling and as an evaporator during heating,
On the contrary, the second heat exchanger 5 is used as an evaporator during cooling and as a condenser during heating.

In the cooling operation, the refrigerant discharged from the compressor 1 flows into the pipe 15 as shown by the arrow in FIG.
The cycle is the same as in the case of FIG. In heating operation,
The inlet and outlet of the four-way valve 8 are switched, and the refrigerant discharged from the compressor 1 flows into the pipe 19. Therefore, it is necessary to attach a dustproof mesh for preventing clogging of the expansion valve throttle to the distributor side of the expansion valve 3 during heating operation. Space saving can be achieved by incorporating this dustproof net together in the pipe 12 in which an orifice for flow control is incorporated. Further, since the pipe shape is the same as in the case of FIG. 1 and is not changed, the effect of suppressing the pipe vibration and the refrigerant flow noise is the same as that of the first embodiment.

FIGS. 4 and 5 show the third and fourth parts, respectively.
2 shows the configuration of the refrigerant-saving air conditioner that is the embodiment of the present invention and the flow of the refrigerant during the cooling operation.

In the cooling air conditioner of the third embodiment shown in FIG. 4, the capillary tube 13 is provided in the pipe between the first heat exchanger 2 which is the condenser and the expansion valve 3. Different from the first embodiment, the other structure is the same as that of the first embodiment. In the present embodiment, the refrigerant condensed and liquefied in the condenser is decompressed by the capillary tube 13 and flows into the expansion valve 3 as a gas-liquid two-phase flow.

In the air conditioner for both heating and cooling according to the fourth embodiment shown in FIG. 5, the capillary tube 13 is provided in the pipe between the first heat exchanger 2 and the expansion valve 3 to achieve the second embodiment. Different from the example, the other configuration is the same as that of the second embodiment. In this embodiment, the refrigerant condensed and liquefied in the first heat exchanger during the cooling operation is depressurized by the capillary tube 13 and becomes a gas-liquid two-phase flow and flows into the expansion valve 3.

As a result, in the air conditioner shown in FIGS. 4 and 5, the gas-liquid two-phase flow flows in the pipe 16 through which only the normal liquid refrigerant flows in the air conditioner shown in FIGS. The required amount of refrigerant is reduced. However, in the air conditioners shown in FIGS. 4 and 5, the inlet of the expansion valve 3 is always a gas-liquid two-phase flow, which is a flow accompanied by pressure pulsation. Therefore,
Even in such a case, by using the pipe shape shown in FIG. 2, the generation and promotion of pressure pulsation are suppressed, and as a result, pipe vibration and refrigerant flow noise are reduced.

6 to 8 show another embodiment of the pipe shape from the expansion valve to the distributor. FIG. 6 shows an example in which a U-shaped pipe 28 is used as a connecting pipe instead of the L-shaped pipe 11 in FIG. 2, and the radius of curvature of the bent portion closest to the expansion valve distributor side pipe 24 is set as described above. It corresponds to pipe vibration and refrigerant flow noise.

FIG. 7 shows a connecting pipe 3 having the same pipe inner diameter as the expansion valve distributor side pipe 24 instead of the L-shaped pipe 11 in FIG.
6 shows an example in which the change in the cross-sectional area of the refrigerant channel is eliminated,
The effect on the refrigerant flow due to the change in cross-sectional area is eliminated.

FIG. 8 shows an example in which a semi-circular pipe 29 is used as a connecting pipe in place of the L-shaped pipe 11 in FIG. 2, and the axes of both ends of the semi-circular pipe 29 are connected to the axis of the expansion valve distributor side pipe 24 and the pipe. They are arranged so as to coincide with the 12 axes.
According to this connecting pipe, the bending of the refrigerant flow path between the expansion valve 3 and the distributor 4 can be made into a single bent portion having a large radius, and the flow can smoothly transition from the vertical downward flow to the vertical upward flow. Further, since the radius of curvature of the bent portion can be increased, the influence of the pipe shape on the refrigerant flow is reduced.

FIG. 9 shows a modification in which a distribution joint pipe 31 is provided between the distribution pipe 14 and the heat exchanger inlet pipe 30 in the first to fourth embodiments. The distribution pipe 14, the distribution joint pipe 31, and the heat exchanger inlet pipe 30 gradually increase in cross-sectional area in the pipe. At this time, the heat exchanger inlet pipe 30 has an inner diameter of 6.8 mm, the distribution joint pipe 31 has inner diameters of 4.95 mm and 4.6 mm, and the distribution pipe 14 has inner diameters of 2.36 mm and 2.7.
A 6 mm tube was used. As a result, the flow velocity when flowing into the second heat exchanger 5 is reduced, the flow is prevented from expanding rapidly, and the occurrence of vortices in the expanded portion and the occurrence of pressure pulsation are reduced. . Further, it is desirable that the distribution joint pipe 31 has a small pressure loss, and that there is no problem in cycle performance. Further, since the distribution joint pipe 31 is provided, the piping structure of the piping from the expansion valve 3 to the distributor 4 can be afforded, so that the piping structure can be made flexible even in the vibration plane of the pipe, and the second heat exchanger can be provided. It was possible to diverge the vibrational energy that should propagate to the device by shaking the pipe from the expansion valve 3 to the distributor 4.

FIG. 10 shows an example of the rate of change in the cross-sectional area of the pipe when the distribution joint pipe 31 is provided between the distribution pipe 14 and the heat exchanger inlet pipe 30 as shown in FIG. Assuming that the pipe inner cross-sectional area of the heat exchanger inlet pipe 30 is A3, the pipe inner cross-sectional area of the distribution joint pipe 31 is A2, and the pipe inner cross-sectional area of the distribution pipe 14 is A1, the distribution pipe 14 and the distribution pipe 14 are distributed in the case of the above pipe diameter. Joint pipe 3
The ratio A2 / A1 of the cross-sectional area in the pipe with 1. is 4.40 to 2.78
Further, the in-pipe sectional area ratio A3 / A2 between the distribution joint pipe 31 and the heat exchanger inlet pipe 30 is 2.19 to 1.89.

FIG. 11 shows that in each of the first to fourth embodiments, the distribution pipe 14 between the distributor 4 and the heat exchanger inlet pipe 30 has a large diameter side on the heat exchanger inlet pipe 30 side. An example is shown in which the distributor 4 side is a taper tube having a small diameter side, and the pipe cross-sectional area gradually increases toward the second heat exchanger. Also in this case, as in the case of the example shown in FIG.
The sudden change of the refrigerant flow was reduced, and the pressure pulsation and the generation of vortices in the enlarged inner diameter area were reduced.

FIG. 12 shows an example in which a flexible vinyl pipe is used for the distribution pipe 14 between the distributor 4 and the heat exchanger inlet pipe 30 in each of the first to fourth embodiments. . This prevents pipe vibration generated in the pipe from the expansion valve 3 to the distributor 4 from propagating to the second heat exchanger 5 (vibration isolation), and causes noise due to resonance of the second heat exchanger 5. Suppressed

FIG. 13 shows an example in which a damping material 35 such as butyl rubber, butyl sheet or putty is attached around the heat exchanger inlet / outlet piping group 34 in each of the first to fourth embodiments. In this example, since the damping material 35 is attached with a sandwich structure in which the periphery of the heat exchanger inlet / outlet pipe group 34 is sandwiched, the attachment is easy and the workability is good. Further, by attaching a damping material to the heat exchanger inlet / outlet piping group 34, in terms of vibration, it is substantially equivalent to increasing the wall thickness of the piping and increasing the mass. Three
Due to the viscous effect of 5, the pipe vibration is absorbed in this portion, and the vibration energy is reduced. Therefore, the vibration energy propagating to the second heat exchanger 5 becomes small, and as a result, noise is generated due to resonance of the second heat exchanger 5. Could be reduced.

FIG. 14 shows that in each of the first to fourth embodiments, the expansion valve main body 22 is connected to the first heat exchanger side of the expansion valve main body 22 installed in the indoor unit, and the expansion valve main body 22 is connected to the expansion valve main body 22. This is an example in which the damping material 35 is attached to the pipes up to the distributor 4 and around the distributor 4 including 22. The vibration damping material 35 is intended to reduce the pipe vibration generated in this portion. As a result of attaching the damping material 35, it is possible to reduce the pressure pulsation generated by the refrigerant flow in the pipe from the expansion valve 3 installed in the indoor unit to the second heat exchanger distributor side inlet, and this pressure It was possible to reduce pipe vibration caused by pulsation. Furthermore, it was possible to reduce pressure pulsation and pipe vibration propagating to the heat exchanger, which easily promotes vibration and noise. Therefore, the refrigerant flow noise generated by the refrigerant flowing in the indoor unit is reduced, and the abnormal noise such as the intermittent flow noise is removed, the noise reduction is promoted, and the comfort is improved.

As described above, according to the above embodiment, the flow state of the refrigerant gas-liquid two-phase flow flowing in the pipe from the expansion valve arranged in the indoor unit of the air conditioner to the heat exchanger is improved. Since the generation and promotion of pressure pulsation due to the gas-liquid two-phase flow can be suppressed, resonance in the heat exchanger can also be prevented. Further, the pipe vibration induced by the pressure pulsation is also reduced by using the damping material, and the propagation of the pipe vibration to the heat exchanger is suppressed, so that the heat exchanger does not resonate.

[0053]

EFFECT OF THE INVENTION The level of refrigerant flow noise is reduced, the occurrence of intermittent flow noise can be prevented, and comfort is improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of a main part of a first embodiment of an air conditioner of the present invention.

FIG. 2 is a front view showing details of a portion of the embodiment shown in FIG.

FIG. 3 is a schematic diagram showing a main configuration of a second embodiment of the air conditioner of the present invention.

FIG. 4 is a schematic diagram showing a configuration of a main part of a third embodiment of the air conditioner of the present invention.

FIG. 5 is a schematic diagram showing a main configuration of a fourth embodiment of the air conditioner of the present invention.

FIG. 6 is a front view showing a modified example of the portions of the first to fourth embodiments of the present invention.

FIG. 7 is a front view showing another modification of the portions of the first to fourth embodiments of the present invention.

FIG. 8 is a front view showing still another modification of the portions of the first to fourth embodiments of the present invention.

FIG. 9 is a partial perspective view showing an example in which a distribution joint pipe is provided between a distribution pipe and a heat exchanger inlet pipe in the first to fourth embodiments of the present invention.

FIG. 10 is a cross-sectional view that schematically shows the relationship between the cross-sectional areas of the distribution pipe, the distribution joint pipe, and the heat exchanger inlet pipe shown in FIG.

FIG. 11 is a partial perspective view showing an example of using a tapered pipe as a distribution pipe in the first to fourth embodiments of the present invention.

FIG. 12 is a partial perspective view showing an example in which a flexible member is used for the distribution pipe in the first to fourth embodiments of the present invention.

FIG. 13 is a perspective view showing a state in which a damping material is attached to the heat exchanger inlet / outlet pipe group in the first to fourth embodiments of the present invention.

FIG. 14 is a front view showing a state in which a damping material is attached to the expansion valve front-rear piping in the first embodiment of the present invention.

[Explanation of symbols]

1 Compressor 2 1st heat exchanger (condenser) 3 Expansion valve 4 Distributor 5 2nd heat exchanger (evaporator) 8 Four-way valve 9 Outdoor fan 10 Indoor fan 11,36 Connection pipe (L-shaped pipe) 12 Pipe 13 Capillary Tube 14 Distribution Pipe 15, 16, 17, 19 Pipe 20 Outdoor Unit 21 Indoor Unit 22 Expansion Valve Main Body 23 Expansion Valve First Heat Exchanger Side Pipe 24 Expansion Valve Distributor Side Pipe 25 Dustproof Net Built-in Pipe 26 Dustproof Mesh 27 Orifice 28 U-shaped pipe 29 Half-arc pipe 30 Heat exchanger inlet pipe 31 Distribution joint pipe 34 Heat exchanger inlet / outlet pipe group 35 Damper A1 Minute pipe passage cross-sectional area A2 Distribution joint pipe passage cross-section A3 Heat exchanger inlet pipe passage Cross-sectional area R Curved pipe radius of curvature.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Joji Okamoto 390 Muramatsu, Shimizu-shi, Shizuoka Hitachi, Ltd. Shimizu Plant (72) Inventor Shinichi Shimoide 502, Jinmachi, Tsuchiura-shi, Ibaraki Nitate Manufacturing Co., Ltd. Inside the Mechanical Research Laboratory (72) Taichi Sato, 502 Jinritsu-cho, Tsuchiura-shi, Ibaraki Prefecture Hiritsu Seisakusho Co., Ltd. 72) Inventor Toshihiko Fukushima 502 Jinrachicho, Tsuchiura-shi, Ibaraki, Institute of Mechanical Research, Hiritsu Seisakusho Co., Ltd. (72) Shunji Sasaki, 390 Muramatsu, Shimizu, Shizuoka Hitachi, Ltd. 390 Muramatsu, Shimizu City, Shizuoka Prefecture Inside the Shimizu Plant, Hitachi, Ltd. (72) Inventor Hiroki Terada Kiyo Shizuoka Ichimura pine 390 address Hitachi Seisakusho Shimizu in the factory

Claims (14)

[Claims] 1. At least a compressor, a first heat exchanger, an expansion valve, a distributor, and a second heat exchanger are connected by piping,
The refrigerant is circulated in the order of the compressor, the first heat exchanger, the expansion valve, the distributor, the second heat exchanger, and then the compressor again, and the refrigerant condensed and liquefied by the first heat exchanger is transferred by the second heat exchanger. In an air conditioner composed of a refrigeration cycle that evaporates and cools,
The compressor to the first heat exchanger are arranged in the outdoor unit, the expansion valve to the second heat exchanger are arranged in the indoor unit, and the expansion from the expansion valve of the indoor unit to the second heat exchanger is expanded. The first heat exchanger side piping axis of the expansion valve connected to the valve inlet should be substantially orthogonal to the direction of gravity, and the expansion valve distributor side piping axis connected to the outlet of the expansion valve should be substantially parallel to the direction of gravity. An expansion valve is installed in the pipe, and a pipe having an orifice connected to the distributor inlet provided on the refrigerant pipe extending from the expansion valve to the second heat exchanger is installed so that its pipe axis is substantially aligned with the gravity direction. And the expansion valve distributor-side pipe connected to the expansion valve outlet is connected by at least one bent pipe, and the distributor and the second heat exchanger are connected to each other. An air conditioner characterized by being connected by piping 2. At least a compressor, a four-way valve, a first heat exchanger, an expansion valve, a distributor, and a second heat exchanger are connected by piping, and refrigerant is sequentially supplied from the compressor to the four-way valve and the first heat. When the first heat exchanger is used as the condenser and the second heat exchanger is circulated in the forward cycle of passing through the exchanger, the expansion valve, the distributor, and the second heat exchanger and then back to the compressor through the four-way valve. When the refrigerant functions as an evaporator, and when the refrigerant is circulated in the reverse cycle of the forward cycle and the reverse direction, the cooling and heating cycle is configured so that the second heat exchanger functions as the condenser and the first heat exchanger functions as the evaporator. In the air conditioner, the compressor to the first heat exchanger are arranged in the outdoor unit, the expansion valve to the second heat exchanger are arranged in the indoor unit, and the expansion valve of the indoor unit is arranged in the second heat exchanger. In the leading pipe, the expansion valve first connected to the second heat exchanger side of the expansion valve 1 Expansion so that the pipe axis of the heat exchanger side pipe is almost orthogonal to the direction of gravity, and that the pipe axis of the expansion valve distributor side pipe connected to the distributor side of the expansion valve is almost parallel to the direction of gravity A valve is arranged, and a pipe having an orifice connected to the expansion valve side of the distributor and a dustproof net is arranged so that its pipe axis is substantially parallel to the direction of gravity,
The air characterized in that the orifice / dust-proof net built-in pipe and the expansion valve distributor side pipe are connected by at least one bent pipe, and the distributor and the second heat exchanger are connected by a plurality of pipes. Harmony machine. 3. A compressor, a first heat exchanger, a pressure reducing mechanism, which is formed by connecting at least a compressor, a first heat exchanger, a pressure reducing mechanism, an expansion valve, a distributor, and a second heat exchanger with a pipe. Expansion valve,
In an air conditioner that constitutes a refrigeration cycle in which the refrigerant is circulated in the order of the distributor, the second heat exchanger, and the compressor again,
The compressor to the decompression mechanism are arranged in the outdoor unit, the expansion valve to the second heat exchanger are arranged in the indoor unit, and in the pipe from the expansion valve to the second heat exchanger in the indoor unit, the expansion valve upstream side So that the pipe axis of the expansion valve first heat exchanger side pipe connected to the is substantially orthogonal to the gravity direction, and the pipe axis of the expansion valve distributor side pipe connected to the expansion valve downstream side is substantially parallel to the gravity direction. The air conditioner is characterized in that the expansion valve is arranged so as to become, and the distributor and the second heat exchanger are connected by a plurality of pipes. 4. A compressor, a four-way valve, a first heat exchanger, a pressure reducing mechanism, an expansion valve, a distributor, and a second heat exchanger are connected by piping to form a refrigerant. First
When the heat exchanger, the pressure reducing mechanism, the expansion valve, the distributor, and the second heat exchanger are circulated in the forward cycle of returning to the compressor via the four-way valve, the first heat exchanger is used as the condenser and the second heat exchanger is used. When the heat exchanger is made to function as an evaporator and the refrigerant is circulated in the reverse cycle of the forward cycle and the reverse direction, a cooling and heating cycle is made in which the second heat exchanger functions as the condenser and the first heat exchanger functions as the evaporator. In the constituent air conditioners,
The compressor to the decompression mechanism are arranged in the outdoor unit, the expansion valve to the second heat exchanger are arranged in the indoor unit, and the pressure reduction of the expansion valve in the pipe from the expansion valve of the indoor unit to the second heat exchanger. The pipe axis of the expansion valve first heat exchanger side pipe connected to the mechanism side is substantially orthogonal to the gravity direction, and the pipe axis of the expansion valve distributor side pipe connected to the distributor side of the expansion valve is gravity. The expansion valve is arranged so as to be substantially parallel to the direction, and the piping connected to the distributor provided on the refrigerant pipe from the expansion valve to the second heat exchanger and having a built-in dustproof mesh is connected to the pipe. Arranged so that the axis is substantially parallel to the direction of gravity, and connecting the orifice / dust-proof net built-in pipe and the expansion valve distributor side pipe with at least one bent pipe, and the distributor and the second heat exchanger. Is an air conditioner characterized by being connected with multiple pipes 5. A pipe axis connected to the distributor side of the expansion valve is substantially parallel to the direction of gravity. An expansion valve distributor side pipe and a pipe axis connected to the expansion valve side of the distributor are substantially parallel to the direction of gravity. The air conditioner according to any one of claims 1, 2, 3 and 4, wherein a radius of curvature of a bent portion of a pipe connecting to the pipe closest to the expansion valve is at least 30 mm. 6. A pipe axis connected to the distributor side of the expansion valve is substantially parallel to the gravity direction. An expansion valve distributor side pipe and a pipe axis connected to the expansion valve side of the distributor are substantially parallel to the gravity direction. The air conditioner according to any one of claims 1, 2, 3 and 4, wherein the pipe connecting to the pipe is a bent pipe having at least two bent portions. 7. A pipe axis connected to the distributor side of the expansion valve is substantially parallel to the gravity direction. An expansion valve distributor side pipe and a pipe axis connected to the expansion valve side of the distributor are substantially parallel to the gravity direction. The air conditioner according to any one of claims 1, 2, 3 and 4, wherein the pipe connecting to the pipe is a semicircular pipe. 8. A pipe axis connected to the distributor side of the expansion valve is substantially parallel to the direction of gravity. An expansion valve distributor side pipe and a pipe axis connected to the expansion valve side of the distributor are substantially parallel to the direction of gravity. The air conditioner according to any one of claims 1, 2, 3 and 4, wherein the diameter of the pipe connecting to the pipe is the same as the diameter of the expansion valve distributor side pipe. 9. The inner diameter of a plurality of pipes connecting the distributor and the second heat exchanger is increased stepwise in the direction from the distributor to the second heat exchanger. The air conditioner according to any one of 2, 3, and 4. 10. An inner diameter of a plurality of pipes connecting the distributor and the second heat exchanger is smoothly and steplessly expanded from the distributor toward the second heat exchanger. The air conditioner according to any one of claims 1, 2, 3 and 4. 11. The inner diameters of a plurality of pipes connecting the distributor and the second heat exchanger, the cross-sectional area of the pipe near the distributor is A1, the cross-sectional area of the pipe near the second heat exchanger is A3, and the distributor. When the cross-sectional area of the middle pipe of the second heat exchanger is A2, the cross-sectional area ratio is 3.5 <A2 / A1 <4.5, 1.9 <A3 / A2 <
The air conditioner according to claim 9, wherein the air conditioner is expanded stepwise so as to be 2.2. 12. The flexible member is used for a plurality of pipes that connect the distributor and the second heat exchanger.
The air conditioner according to any one of 2, 3, and 4. 13. The air conditioner according to any one of claims 1, 2, 3 and 4, wherein a damping material is attached to a pipe at the entrance and exit of the second heat exchanger. 14. The damping material is attached to the piping and piping components from the piping on the outdoor unit side of the expansion valve inside the indoor unit to the distributor. The air conditioner described in Crab.