JP3435626B2 - Air conditioner - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a compressor, a condenser,
The present invention relates to an air conditioner that forms a refrigeration cycle in which an expansion valve and an evaporator are connected by a refrigerant pipe, and particularly relates to an air conditioner that is suitable for reducing refrigerant flow noise generated in the expansion valve.

[0002]

2. Description of the Related Art An expansion valve has a small-diameter refrigerant passage and a valve for restricting and adjusting the opening area of the refrigerant passage in order to adiabatically expand the refrigerant. The narrowed opening area is very narrow, and when liquid refrigerant mixed with bubbles flows into this narrow opening,
The bubbles temporarily block the flow of refrigerant,
After the bubbles pass through the opening, the liquid refrigerant without the bubbles flows into the opening, thereby smoothing the flow of the refrigerant.

In such a case, a pressure change accompanied by a sudden pressure pulsation occurs in the flow of the refrigerant, and a refrigerant flowing sound is generated. The flow of the refrigerant is referred to as a gas-liquid two-phase flow in a state in which bubbles are mixed, but in order to reduce the refrigerant flow noise generated in the gas-liquid two-phase flow, the following proposal is disclosed in Japanese Patent Laid-Open No. 7-146032. It is shown.

The following five expansion valves have been proposed as expansion valves which are arranged in the refrigeration cycle and which regulate the refrigerant flow rate by narrowing the refrigerant passage.

(1) An expansion valve which is provided with means for dividing the flow state of the refrigerant flowing in and out of the expansion valve into minute bubbles.

(2) An expansion valve in which several ultra-fine tubes are arranged in parallel before and after the expansion valve.

(3) An expansion valve in which the inner diameters of the orifices before and after the expansion valve are changed stepwise so as to have a stepped orifice.

(4) An expansion valve in which a conical orifice is arranged in front of and behind the expansion valve, and a thread groove is arranged on the inner circumference of the conical orifice.

(5) An expansion valve in which the expansion valve is a multi-layered orifice and a vibration damping material is arranged in the multi-layered orifice.

[0010]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the technology disclosed in Japanese Patent Publication No. 032, the flow of the refrigerant flowing into the expansion valve is improved by arranging the orifices and the like before and after the expansion valve, and the pressure change accompanied by the rapid pressure pulsation is attenuated.
It is expected that the refrigerant flow noise generated by the pressure pulsation will be reduced.

However, in either case, the shape of the orifice on the connecting pipe side of the expansion valve is made conical, or only the porous body and the ultrafine pipe are arranged on the connecting pipe side of the expansion valve. The shape of the orifice on the throttle side is not improved. Therefore, there is a problem that the refrigerant that passes through the throttle portion of the expansion valve and flows out to the orifice on the downstream side directly collides with the end surface of the orifice or the like, and the flow of the refrigerant is disturbed, and refrigerant flow noise (collision noise) is generated.

Further, the orifice or the like is very close to the throttle portion (valve rod) of the expansion valve, and when the inner diameter of the refrigerant passage is narrowed, the flow velocity of the refrigerant rapidly increases, so that the refrigerant directly flows into the expansion valve. It collides with the valve stem with great force. As a result, there is a problem that the valve rod is vibrated and abnormal noise is generated. In particular, when the refrigerant horizontally flows into the valve rod of the expansion valve, large vibrations often occur, and there is a concern that the valve rod may be damaged.

In all cases, the inner diameter of the orifice is only constant or is changed stepwise, and no consideration is given to the inflow direction of the refrigerant with respect to the valve rod of the expansion valve, the flow velocity of the refrigerant and the dryness. This cannot cope with the case where the refrigerant is a gas-liquid two-phase flow and the flow state greatly differs depending on the mixing ratio (dryness) of gas and liquid, the flow direction, and the flow velocity of gas and liquid. For example, when the refrigerant circulation amount changes in the flow range of the air conditioner, the dryness is low, and the gas and liquid flow velocities are low, gas and liquid separate and flow, so there are large bubbles. However, there is a problem that intermittent refrigerant flow noise occurs.

In addition to these, the following problems are listed. In the expansion valve of the above (1), the porous body is provided as a means for making the flow state of the refrigerant flowing in and out of the expansion valve before and after the expansion valve into fine bubbles, but the porous body itself blocks the flow of the refrigerant. Therefore, the resistance becomes considerably large, and the refrigerant is not in an ideal refrigeration cycle state, and there is concern that the flow state of the refrigerant deteriorates. Further, by providing the porous body, when impurities such as dust are mixed in the refrigeration cycle, the porous body is likely to be clogged with the impurities and there is a risk that the flow of the refrigerant is blocked.

In the expansion valve of the above (2), several ultrafine tubes arranged in parallel before and after the expansion valve are arranged to pass through, but the ultrafine tube has the same problem as the porous body of the above (1). Conceivable. Furthermore, it is difficult to install ultra-fine pipes, and there is concern that vibration and noise may occur due to variations in installation and insufficient fixing.

In the expansion valve of the above (3), the inner diameter of the orifice portion before and after the expansion valve is reduced stepwise to arrange the stepped orifice, but the inner diameter of the orifice portion is changed stepwise. In this case, since the difference between the inner diameter of the orifice on the connection pipe side and the inner diameter of the connection pipe is small, the edge (the surface of each step) in the refrigerant passage becomes small. For this reason, at the small edge in the refrigerant passage, the bubbles existing in the refrigerant state of the gas-liquid two-phase flow pass without being broken and are not miniaturized. That is, air bubbles in the refrigerant often pass through the hole in the center of the orifice having a stepped shape as they are, and the effect of improving the flow is low.

In the expansion valve of the above (4), a conical orifice is arranged before and after the expansion valve, and a threaded groove is arranged on the inner circumference of the conical orifice. In a flow mode called churn flow or plug flow in which large bubbles are present intermittently, it is difficult to smoothly guide the refrigerant along the thread groove, and conversely the thread groove disturbs the refrigerant flow. Is concerned.

In the expansion valve of the above (5), the expansion valve is a multi-layered orifice, and the vibration damping material is arranged in the multi-layered orifice. However, in the portion where the connection pipe of the expansion valve and the multi-layered orifice are in contact with each other. Since there is a vibration isolator, the rigidity between the expansion valve and the connecting pipe is greatly reduced, and the expansion valve itself may vibrate, and there is a problem that the vibration of the pipe becomes large due to the eigenvalue of the vibration.

As described above, the refrigerant flow noise is closely related to the refrigerant state of the gas-liquid two-phase flow, and particularly churn flow and plug flow in which large air bubbles are intermittently present in the refrigerant flow. When flowing into the expansion valve, the pressure change accompanied by a sudden pressure pulsation is large, so that a loud refrigerant flow noise is intermittently generated.

Therefore, an object of the present invention is to provide an air conditioner which reduces the refrigerant flow noise intermittently generated from the expansion valve due to the refrigerant state of the gas-liquid two-phase flow of the refrigerant.

[0021]

In order to achieve the above object, the air conditioner of the present invention comprises a compressor, a condenser, an expansion valve,
In an air conditioner in which an evaporator is connected by a refrigerant pipe to form a refrigeration cycle using a gas-liquid two-phase refrigerant, (1) an expansion valve is a valve body and can slide up and down in the valve body. A valve rod, a horizontal flow passage extending from the inlet formed on the side surface of the valve disc to the valve rod at right angles to the valve rod, a valve seat facing the tip of the valve rod, and an outlet formed on the valve body face from the valve seat. It consists of a vertical flow path leading to it, an inlet side joint pipe connected to the horizontal flow channel inlet, and an outlet side joint pipe connected to the vertical flow channel outlet, (2)
The inlet side joint pipe has an orifice and a tapered hole that diverges from the orifice.The inlet side orifice pipe is connected so that the taper hole is located on the expansion valve side, and the outlet side joint pipe has a tapered hole that diverges from the orifice and the orifice. Connect the inlet orifice pipe so that the taper hole is located on the expansion valve side, and connect the inlet orifice pipe and outlet orifice pipe to the valve.
Keep a distance from the rod, connect the inlet-side orifice pipe with the refrigerant pipe on the upstream side during the cooling cycle, connect the outlet-side orifice pipe with the refrigerant pipe on the downstream side, and (3) connect the inlet-side orifice pipe. Refrigerant flowing in at right angles to the valve stem with an orifice diameter larger than that of the outlet orifice pipe
It is characterized in that the flow velocity of is reduced .

The orifice diameter of the inlet-side orifice pipe is adjusted so as to be an annular flow or bubble flow defined by the ratio of the gas flow velocity and the liquid flow velocity of the gas-liquid two-phase flow existing within the flow range of the air conditioner. It is preferable to select it.

Further, the taper hole side of the inlet side orifice pipe is fitted into the joint pipe, and the upstream side refrigerant pipe is attached so as to cover the joint pipe from the orifice side of the orifice pipe to construct the joint joint portion. It is preferable to fix the orifice pipe in the pipe by brazing, or by brazing a similar joint joint between the outlet side orifice pipe, the outlet side joint pipe and the downstream side refrigerant pipe.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below.
A description will be given with reference to the drawings. First, the refrigeration cycle of the air conditioner according to the present invention will be described with reference to FIG. The refrigeration cycle includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3,
The expansion valve 4, the diversion / combiner 8 and the indoor heat exchanger 5 are connected to the pipes 6, 7, 11a, 11b, 11c, 11d and the diversion pipe 9.
a, 9b, 9c, 9d are connected. In this embodiment, the pipe 7 between the expansion valve 4 and the diversion / merger 8 has a strainer and an orifice pipe in the pipe.

During the cooling operation, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 is supplied to the outdoor heat exchanger 3 via the four-way valve 2 and is supplied to the outdoor heat exchanger 3 by the air sent by the fan 10a. It is cooled and condensed to become a high-pressure liquid refrigerant. This liquid refrigerant flows into the expansion valve 4, takes heat from the indoor air sent by the fan 10b in the indoor heat exchanger 5, and evaporates to become a gas refrigerant. This gas refrigerant returns to the compressor 1 again via the four-way valve. On the other hand, during the heating operation, the four-way valve 2 reverses the flow of the refrigerant. That is, the refrigerant is the compressor 1,
The four-way valve 2, the indoor heat exchanger 5, the expansion valve 4, the outdoor heat exchanger 3, the four-way valve 2, and the compressor 1 flow in this order.

As described above, the liquid refrigerant normally flows into the expansion valve 4, but depending on the operating conditions of the air conditioner and the indoor and outdoor air temperature conditions, and when the connecting pipe between the indoor unit and the outdoor unit is long, Due to pressure loss, the outdoor heat exchanger 3 during cooling operation
In the heating operation, the indoor heat exchanger 5 may not be completely condensed, and the refrigerant may be in a gas-liquid two-phase flow state. Further, when the number of the diversion pipes 9 connecting the diversion / merging unit 8 and the indoor heat exchanger 5 increases due to the size of the indoor heat exchanger 5, the refrigerant flow state and dryness of each diversion pipe 9 become uniform. It is difficult and the distribution of the refrigerant is deteriorated.

The refrigerant flow sound is closely related to the refrigerant state of the gas-liquid two-phase flow, and in particular, churn flow and plug flow in which large bubbles are intermittently present in the refrigerant flow are expansion valves. When flowing into No. 4, since the pressure change accompanied by a sudden pressure pulsation is large, a large refrigerant flow noise is intermittently generated.

The portion provided with the means for reducing the flow noise of the refrigerant is a portion 12 surrounded by a broken line in FIG. 2, the details of which are shown in FIG. FIG. 1 is a diagram showing a flow passage structure around an expansion valve, which is provided with an orifice pipe that characterizes the air conditioner of the present invention. The portion surrounded by the broken line in FIG. 1 is the expansion valve 4. The expansion valve 4 is formed on the valve body 16, a valve rod 17 that slides up and down in the valve body 16, a motor 15 that is installed on the valve body 16 and drives the valve rod 17, and a side surface of the valve body 16. Horizontal flow path 16a extending from the inlet to the valve rod 17 at right angles to the valve rod 17
A valve seat 16b that is connected to the horizontal flow path 16a and faces the tip of the valve rod 17, a vertical flow path 16c that descends from the valve seat 16b and reaches the outlet on the lower surface of the valve element 16, and a horizontal channel 16a inlet inlet side joint An orifice pipe 20 as an inlet-side orifice pipe connected via a joint pipe 13 as a pipe, and an outlet-side orifice pipe connected to an outlet of the vertical flow channel 16c via a joint pipe 14 as an outlet-side joint pipe. It is composed of an orifice pipe 21. The upstream pipe 6 is connected to the orifice pipe 20, and the downstream refrigerant pipe 7 is connected to the orifice pipe 21. The above-mentioned upstream and downstream and the inlet and outlet correspond to the refrigerant flow in the cooling cycle. In the heating cycle, the refrigerant flows in opposite directions, so that the upstream and downstream sides and the inlet and outlet are opposite to each other. In FIG. 1, the refrigerant flows in from the pipe 6 side during the cooling operation and flows into the expansion valve 4 from the pipe 7 side during the heating operation. In order to improve the effect of reducing the flow noise of the refrigerant in the pipe 7, a strainer 22, an orifice member 18,
19 are installed.

Here, in an actual air conditioner, the pipe connected to the expansion valve 4 always has a bent portion as shown in FIG. In addition, the radius of curvature of the bent portion of the pipe may be very small due to restrictions on the installation space of the pipe. At this time, the flow form of the refrigerant flowing in the bent portion of the pipe changes, and in particular in the gas-liquid two-phase flow, bubbles stay in the bent portion. Further, when the radius of curvature of the bent portion of the pipe is very small, the flow of the refrigerant is likely to be obstructed, and the bubbles accumulated in the bent portion become large, which is pushed out by the liquid refrigerant and causes pressure fluctuation and flow rate fluctuation.
When the disturbed refrigerant that has undergone the pressure fluctuation and the flow rate fluctuation flows into the throttle portion between the valve seat 16b / valve rod 17 of the expansion valve 4, an intermittent refrigerant flow noise is generated. Therefore, it is desirable to increase the radius of curvature of the bent portion of the pipe or to lengthen the straight pipe after the bent portion to improve the flow, but it is often impossible in terms of space.

Therefore, in the present invention, the orifice pipe 2 is provided between the refrigerant pipe 6 and the joint pipe 13 connected to the inlet of the expansion valve 4.
0 and an orifice pipe 21 between the joint pipe 14 connected to the outlet of the expansion valve 4 and the refrigerant pipe 7. The orifice pipe 20 includes an orifice 20a further narrowed from the inner diameters of the connected pipes 6 and 7, and a taper hole 2 following the orifice 20a.
It has 0b. The orifice pipe 21 similarly has an orifice 21a and a tapered hole 21b. The orifice pipes 20 and 21 have tapered holes for the valve seat 1 of the expansion valve 4.
6b / valve rod 17 is arranged so as to be on the side of the throttle portion.

When large bubbles in the refrigerant in a gas-liquid two-phase flow state pass through the orifice tube 20, the orifice of the orifice 20a narrowed down from the inner diameter of the tube 6 by one step is removed except for the tip surface having a large surface area. Bubbles are broken and miniaturized.
Further, by reducing the cross-sectional area of the refrigerant flow path at the orifice 20a, the flow velocity of the refrigerant can be increased, and the liquid phase can be transferred to the inner wall side of the tube and the gas phase near the center of the tube can be changed to an annular flow mode. , Promote the homogenization of bubbles. This is different from churn flow or plug flow in which large bubbles are present intermittently in the flow of refrigerant,
Since the fine bubbles are uniformly and continuously present, the pressure fluctuation is reduced and the intermittent refrigerant flow noise when passing through the expansion valve 4 can be reduced. Further, while the flow of the refrigerant improved by the orifice 20a is not disturbed, the orifice 20a
By the taper hole 20b following the above, it can be smoothly supplied to the throttle portion between the valve seat 16b of the expansion valve 4 and the valve rod 17, and the effect is great. On the contrary, the refrigerant flowing out from the throttle portion of the expansion valve 4 to the orifice 21 on the downstream side does not collide with the end surface of the orifice pipe 21, and the tapered hole 21b having a large inlet area.
Since it is guided by, the collision noise of the refrigerant can be reduced.

Further, by installing the orifice pipes 20 and 21 between the refrigerant pipes 6 and 7 connected to the expansion valve 4 and the joint pipes 13 and 14 of the expansion valve, the orifice 20
a, 21a and the throttle portion (valve rod 17) of the expansion valve 4 are separated from each other, and "When the inner diameter of the refrigerant passage is narrowed, a rapid increase in the flow velocity of the refrigerant causes the refrigerant to directly reach the valve rod 17 of the expansion valve 4. The problem of “collision with a large force” can be solved, and vibration and abnormal noise from the valve rod 17 can be eliminated.

FIG. 1 shows that the orifice diameters of the orifice pipes 20 and 21 are changed depending on the direction of the refrigerant flowing into the expansion valve 4. As described above, when the refrigerant horizontally flows into the valve rod 17 of the expansion valve 4, a large vibration often occurs, so that the refrigerant horizontally flows into the valve rod 17 of the expansion valve 4 ( In the present embodiment, in the case of the flow of the refrigerant during cooling), the flow velocity of the refrigerant is made lower than that in the case where the refrigerant flows vertically into the valve rod 17 of the expansion valve 4 (flow of the refrigerant during heating). The orifice diameter of the orifice tube 20 (d ₁ )
Is made larger than that of the orifice pipe 21 (d ₂ ) to alleviate the load on the valve rod 17.

FIG. 3 is a diagram in which the orifice diameter is selected so as to provide an annular flow or a bubble flow defined by the ratio of the gas flow velocity and the liquid flow velocity of the gas-liquid two-phase flow existing in the refrigerant flow rate range in the air conditioner. is there. Qualitatively, in the annular flow, when the liquid flow velocity is small and the gas flow velocity is large, there are many small bubbles in the center and the surrounding (inner surface of the pipe)
It is in a fluidized form in which liquid is present. The bubble flow is a flow form in which a large number of small bubbles are present uniformly evenly when the liquid flow velocity is high and the gas flow velocity is low.

It is defined by the ratio of the gas flow velocity and the liquid flow velocity of the gas-liquid two-phase flow existing in the flow range of the air conditioner,
Area where intermittent refrigerant flow noise is generated (churn flow, plug flow where large bubbles are intermittently present when liquid flow velocity and gas flow velocity are both small) and region where no refrigerant flow noise is generated (annular flow, bubble flow) By selecting the orifice diameter so as to satisfy the above condition, it is possible to prevent the refrigerant flow noise from being generated due to the difference in the flow rate range of the air conditioner.

FIG. 4 is a view showing the shape and installation of the orifice pipes (19, 20) having an improved brazing property, which is an embodiment of the present invention. When the material of the orifice pipe is different from the material of the refrigerant pipes 6 and 7 connected to the expansion valve and the joint pipes 13 and 14 of the expansion valve, for example, the material of the orifice pipe is brass and the material of the refrigerant pipe and the joint pipe is When each is copper, the brazing property is poor due to the difference in thermal conductivity. Therefore, the orifice pipe is completely covered with the refrigerant pipes 6 and 7 connected to the expansion valve and the joint pipes 13 and 14 of the expansion valve so that the orifice pipe can be fixed inside the pipe. That is, FIG.
As shown in, a collar is provided on the outer periphery of the central portion in the longitudinal direction of an orifice tube having an orifice and a tapered hole following the orifice.
Attach a joint pipe so as to contact the collar and cover the outer periphery of the taper hole side.Further, on the orifice side, attach a refrigerant pipe with an expanded tip to cover the joint pipe from the orifice pipe through the collar, and braze the three. (23) Do. Alternatively, instead of providing a collar, the orifice pipe is stepped by thickening the orifice side and thinning the taper hole side, and attaching a joint pipe to the taper hole side and expanding the orifice side from the orifice pipe to the joint pipe. The attached refrigerant pipes may be attached and the three brazed. As a result, the brazing property can be improved regardless of the material of the orifice pipe, and the leakage of refrigerant due to defective brazing can be eliminated.

[0037]

According to the air conditioner of the present invention, the orifice pipe having the inner diameter reduced by one step from the refrigerant pipe connected to the expansion valve and the tapered hole provided on the throttle portion side of the expansion valve is connected to the expansion valve. By installing it between the refrigerant pipe and the joint pipe of the expansion valve, an end face having a large area is formed at the orifice side end face of the orifice pipe in the refrigerant passage, and in the gas-liquid two-phase flow state, especially the flow of the refrigerant. Breaks large air bubbles inside and miniaturizes them. Furthermore, by reducing the cross-sectional area of the refrigerant passage with the orifice, the flow velocity of the refrigerant can be increased, and it can be transferred to the annular flow mode in which the liquid phase is present on the tube wall and the gas phase is present near the center of the tube. Promote the transformation. As a result, the pressure fluctuation is reduced, and it is possible to remarkably improve the intermittent reduction of refrigerant flow noise when passing through the expansion valve. Further, while the improved refrigerant flow in the orifice pipe is not disturbed, the tapered hole of the orifice pipe allows smooth supply to the throttle portion of the expansion valve, which is a great effect. On the contrary, the collision noise of the refrigerant generated when flowing out from the throttle portion of the expansion valve to the downstream orifice pipe can be mitigated by the tapered hole of the orifice pipe. In addition, by installing the orifice pipe between the refrigerant pipe connected to the expansion valve and the joint pipe of the expansion valve, the distance between the orifice pipe and the throttle portion (valve rod) of the expansion valve can be maintained, and the sudden refrigerant Vibration and abnormal noise from the valve stem due to increased flow velocity are eliminated. By these effects, the pressure fluctuation of the expansion valve section is significantly reduced, and by preventing the vibration of the refrigerant pipe connected to the expansion valve, it is possible to reduce the refrigerant flow noise generated from other piping sections. . In addition, the intermittent refrigerant flow noise generation region (churn flow) is defined by the ratio of the gas flow velocity and the liquid flow velocity of the gas-liquid two-phase flow existing in the direction of the refrigerant flow into the valve stem of the expansion valve and the flow range of the air conditioner.・ By selecting the inner diameter of the orifice pipe so that the refrigerant flow noise is avoided and the region (annular flow, bubble flow) is avoided, the effect of reducing the refrigerant flow noise is further enhanced and air conditioning is achieved. The quietness and comfort of the machine can be improved.

Due to the above-described reduction of the refrigerant flow noise, it is possible to eliminate the need to attach a conventional anti-vibration material such as a butyl sheet or a sound insulation material,
Reduce costs and improve workability.

Further, even when the material of the orifice pipe is different from that of the refrigerant pipe connected to the expansion valve and the joint pipe of the expansion valve, the orifice pipe is connected to the expansion valve and the expansion pipe is connected to the refrigerant pipe. The shape is such that it can be completely covered with a joint pipe and can be fixed inside the pipe, the brazing property can be improved regardless of the material of the orifice pipe, and the leakage of refrigerant due to defective brazing can be eliminated.

[Brief description of drawings]

FIG. 1 is a diagram showing a refrigerant flow path structure around an expansion valve in an air conditioner according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a refrigeration cycle of the air conditioner according to the embodiment of the present invention.

FIG. 3 is a diagram showing a relationship between an orifice diameter, an annular flow and a bubble flow defined by a ratio of a gas flow velocity and a liquid flow velocity of a gas-liquid two-phase flow in an embodiment of the present invention.

FIG. 4 is a diagram showing a shape of a brazing joint portion of an orifice tube according to an embodiment of the present invention.

[Explanation of symbols]

1 compressor 2 four-way valve 3 outdoor heat exchanger 4 expansion valve 5 Indoor heat exchanger 6,7 Connection piping 8-way merging pipe 9a, 9b, 9c, 9d Branch pipe 10a, 10b fan 11a, 11b, 11c, 11d Piping 13,14 fitting pipe 15 motor 16 valve body 17 valve rod 18, 19 Orifice member 20,21 Orifice tube 22 Strainer

Front Page Continuation (72) Inventor Takashi Sano 390 Muramatsu, Shimizu City, Shizuoka Prefecture, Hitachi Ltd., Air Conditioning Systems Division (72) Inventor Atsushi Kobayashi 390 Muramatsu, Shimizu City, Shizuoka Hitachi Shimizu Engineering Co., Ltd. 72) Inventor Hideki Okuzono 390 Muramatsu, Shimizu City, Shizuoka Prefecture, Hitachi, Ltd., Air Conditioning Systems Division (56) Reference JP-A-4-366375 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F25B 41/00 F25B 41/06

Claims (3)

(57) [Claims] 1. An air conditioner in which a compressor, a condenser, an expansion valve, and an evaporator are connected by a refrigerant pipe to form a refrigeration cycle using a refrigerant of gas-liquid two-phase flow. ,
A valve rod slidable up and down in the valve body, a horizontal flow passage extending from the inlet formed on the side surface of the valve body to the valve rod at right angles to the valve rod, a valve seat facing the valve rod tip, consist of a valve seat and a vertical flow path to the outlet formed in the valve body lower surface, and the entrance side joint pipe connected to the inlet horizontal flow path, connected to the vertical flow path outlet and the outlet side joint pipe, the connect the inlet side orifice tube having a diverging taper hole inlet side joint pipe from the orifice and the orifice to the tapered hole is located at the expansion valve side, it has a flared tapered hole from the orifice and the orifice to the outlet side joint pipe Connect the inlet-side orifice pipe so that the taper hole is located on the expansion valve side, and connect the inlet-side orifice pipe and outlet-side orifice pipe.
Take the orifice tube the distance between the valve stem connects the refrigerant pipe on the upstream side in the cooling cycle in the entry side orifice tube, connecting the refrigerant pipe on the downstream side in the outlet side orifice tube, said Inlet side orifice pipe
The orifice diameter should be the same as the orifice diameter of the outlet orifice pipe.
Of the refrigerant flowing in at right angles to the valve stem
An air conditioner characterized by reducing the flow velocity . 2. The orifice diameter of the inlet side orifice pipe is
The air conditioner according to claim 1, wherein the air conditioner is selected so as to have an annular flow or a bubble flow defined by a ratio of a gas flow velocity and a liquid flow velocity of a gas-liquid two-phase flow existing within a flow range of the air conditioner. Machine. 3. A taper hole side of the inlet side orifice pipe is fitted into the joint pipe, and an upstream side refrigerant pipe is attached so as to cover the joint pipe from the orifice side of the orifice pipe, thereby forming a joint joint to form the joint joint portion. The brazing, or the joining joint similar to that on the inlet side orifice pipe side is brazed between the outlet side orifice pipe, the outlet side joint pipe, and the downstream side refrigerant pipe. Air conditioner described.