JP2002098443A - Refrigeration cycle system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a refrigeration cycle system comprising a restrictor which is not closed by a foreign matter in the refrigeration cycle and can reduce flowing sound of refrigerant significantly. SOLUTION: A second flow rate controller 6 comprising a restriction mechanism section 10 coupled in series with a capillary tube 9 and having an orifice 12 between porous bodies 13 and 14 disposed, respectively, on the inlet side and the outlet side of refrigerant, and a two-way valve 8 coupled in parallel with the capillary tube 9 and the restriction mechanism section 10 coupled in series is interposed between first and second indoor heat exchangers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration cycle apparatus such as an air conditioner, and more particularly to a refrigeration cycle apparatus that can reduce the flow noise of a two-phase refrigerant and improve comfort against noise. is there.

[0002]

2. Description of the Related Art Conventionally, in a refrigeration cycle device such as an air conditioner, in order to cope with a load change of the air conditioner,
A variable displacement compressor such as an inverter is used, and the rotation frequency of the compressor is controlled according to the magnitude of the load. By the way, when the rotation speed of the compressor decreases during the cooling operation, the evaporation temperature rises, the dehumidifying ability in the evaporator decreases, or the evaporation temperature rises above the dew point temperature in the room, and there is a problem that the dehumidification cannot be performed. was there.

[0003] In order to improve the reduction of the dehumidifying capacity during the cooling low capacity operation, for example, an air conditioner shown in FIG. 13 has been proposed (see Japanese Patent Application Laid-Open No. 11-51514). FIG. 13 is a refrigerant circuit diagram illustrating a configuration of a conventional air conditioner. In FIG. 13, the air conditioner includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, a first flow control device 4, a first indoor heat exchanger 5, a second flow control device 36, and a second indoor It has a heat exchanger 7 and each component forms a refrigeration cycle connected sequentially by piping.

When the air conditioner performs a cooling operation, the refrigerant flowing out of the compressor 1 passes through the four-way valve 2 and is condensed and liquefied by the outdoor heat exchanger 3. Here, since the two-way valve 38 of the first flow control device 4 is closed, the refrigerant output from the outdoor heat exchanger 3 is depressurized by the expansion device 32 and is evaporated and vaporized in the first indoor heat exchanger 5. Then, the flow returns to the compressor 1 via the four-way valve 2 again. The second flow control device 36 is open.

[0005] On the other hand, when the air conditioner performs the heating operation, the refrigerant exiting the compressor 1 reverses the cooling operation.
It passes through the four-way valve 2 and is condensed and liquefied by the first indoor heat exchanger 5. Here, since the two-way valve 38 of the first flow control device 4 is closed, the refrigerant output from the first indoor heat exchanger 5 is decompressed by the expansion device 32, and is evaporated and vaporized in the outdoor heat exchanger 3. Then, the flow returns to the compressor 1 via the four-way valve 2 again. The second flow control device 36 is open.

On the other hand, when performing the dehumidifying operation, the two-way valve 38 of the first flow control device 4 is opened, and the second flow control device 3 is opened.
6 controls the refrigerant flow rate. By controlling the refrigerant flow rate by the second flow rate control device 36, the first indoor heat exchanger 5 operates as a condenser, that is, a reheater, and the second indoor heat exchanger 7 operates as an evaporator. As a result, since the indoor air is heated by the first indoor heat exchanger 5, the dehumidifying operation in which the decrease in the room temperature is small can be performed.

[0007]

However, in the above-mentioned conventional air conditioner, a flow control valve having an orifice is usually used as the second flow control device 36 installed on the indoor unit side. The flow noise of the refrigerant generated when the refrigerant passes through the orifice is large, which is a factor of deteriorating the indoor environment. In particular, at the time of the dehumidifying operation, the inlet of the second flow control device 36 becomes a gas-liquid two-phase refrigerant, and there is a problem that the refrigerant flow noise increases.

Therefore, as a measure to reduce the refrigerant flow noise of the second flow control device 36 during the dehumidifying operation, an air conditioner in which a plurality of cut grooves and an orifice-shaped throttle flow path comprising a valve element are provided in the flow control valve. (Japanese Patent Laid-Open No. 11-5)
No. 1514). In this refrigerant flow noise reduction measure, the throttle section is designed to continuously flow gas-liquid two-phase refrigerant through a plurality of orifice-shaped flow paths, but the number of flow paths that can be arranged is limited due to processing. There is a problem that it is not effective and the refrigerant flow noise increases. As a result, it is necessary to take additional measures such as providing a sound insulation material and a vibration damping material around the second flow control device 6, and there are problems such as an increase in cost, a deterioration in installation, and a deterioration in recyclability. Still remained.

Further, in the flow control device used in the air conditioner described in Japanese Patent Application Laid-Open No. 7-146032, a porous body is provided as a filter upstream and downstream of the throttle in order to reduce refrigerant flow noise. I have. However, since the distance between the porous body and the throttle portion is large, gas-liquid two-phase refrigerant cannot be continuously and effectively supplied to the throttle portion,
As a result, there is a problem that the refrigerant flow noise becomes large.

[0010] The present invention has been made in view of the above,
An object of the present invention is to provide a refrigeration cycle apparatus having a throttle device that can significantly reduce refrigerant flow noise and that is not blocked by foreign matter in the refrigeration cycle.

[0011]

In order to achieve the above object, a refrigeration cycle apparatus according to the present invention comprises: a capillary tube;
A throttle mechanism portion having an orifice sandwiched between porous bodies provided on the inlet side and the outlet side with respect to the flow of the refrigerant, and the capillary tube and the throttle mechanism portion connected in series; A flow control unit having a two-way valve connected in parallel is disposed between the first indoor heat exchanger and the second indoor heat exchanger.

According to this invention, the gas-liquid two-phase refrigerant is mixed by the capillary tube, flows into the throttle mechanism, and passes through the porous body having numerous fine vent holes, thereby forming the refrigerant vapor slag and the refrigerant bubbles. Becomes small gas bubbles and the refrigerant flows into a homogeneous gas-liquid two-phase state, preventing the collapse of refrigerant vapor slag and refrigerant bubbles, and the refrigerant velocity caused by the simultaneous passage of vapor refrigerant and liquid refrigerant through the orifice. No fluctuations in pressure, no fluctuations in pressure, and a complicated flow path inside the porous body repeatedly changes the pressure of the refrigerant inside the porous body and converts a part of the refrigerant into heat energy, so that the pressure fluctuation is kept constant. I have to.

[0013] A refrigeration cycle apparatus according to the next invention comprises:
In the above invention, the capillary and the throttle mechanism are disposed substantially vertically along the flow direction of the refrigerant, the refrigerant flowing through the capillary flows vertically upward from below, and the refrigerant flowing through the throttle mechanism includes: It is characterized by flowing downward from vertically above.

According to the present invention, by connecting a capillary tube that does not cause gas-liquid separation to the inlet side of the throttle mechanism, generation of refrigerant flow noise is prevented regardless of the arrangement of the throttle mechanism. I have.

[0015] The refrigeration cycle apparatus according to the next invention comprises:
A flow control unit including a two-way valve and a throttle mechanism unit connected in parallel to the two-way valve and having an orifice sandwiched between porous bodies provided on the inlet and outlet sides of the refrigerant is provided in the first chamber. The throttle mechanism is disposed between the heat exchanger and the second indoor heat exchanger, and the throttle mechanism is disposed substantially horizontally along the flow direction of the refrigerant.

According to the present invention, when the refrigerant passes through the orifice in which the flow of the refrigerant is in the horizontal direction, the vapor slug of the two-phase refrigerant rises above the front space of the inlet-side porous body in the throttle mechanism, and rises below the lower part. Although the liquid phase accumulates and separates, the vapor slag passes through the porous body to become fine bubbles, passes through the orifice, and pressure fluctuation is suppressed.

[0017] The refrigeration cycle apparatus according to the next invention comprises:
In the above invention, the throttle mechanism is characterized in that the porous body is fixed by a caulking portion provided on a peripheral portion of an orifice holding member forming the orifice.

According to the present invention, since the porous body is fixed to the orifice holder by the entire circumference caulking by the caulking portion, even if the outer peripheral portion of the porous body has burrs, the entire circumference is caulked. The burrs can be prevented from flowing out onto the refrigerant circuit.

[0019] The refrigeration cycle apparatus according to the next invention comprises:
In the above invention, a space is formed between the orifice and the porous body.

According to the present invention, by providing a space between the orifice and the porous body, the flow path between the porous body and the orifice can be widened, and foreign matter is laminated on a part of the mesh of the porous body. Even enable multiple channels,
Refrigerant clogging is avoided.

[0021] The refrigeration cycle apparatus according to the next invention comprises:
In the above invention, a distance of the space formed between the orifice and the porous body on the refrigerant inlet side in a refrigerant flow direction is equal to or less than a diameter of the orifice.

According to the present invention, the distance of the space provided between the orifice and the porous body on the refrigerant inlet side is made smaller than the diameter of the orifice. The bubbles are prevented from re-aggregating to form large bubbles exceeding the diameter of the orifice, and the occurrence of pressure fluctuation is suppressed while avoiding the risk of clogging.

The refrigeration cycle apparatus according to the next invention is:
In the above invention, a distance of the space formed between the orifice and the porous body on the refrigerant outlet side in a refrigerant flow direction is equal to or larger than a diameter of the orifice.

According to this invention, the distance of the space formed between the porous body on the outlet side and the orifice is set to be equal to or larger than the diameter of the orifice, and the flow velocity of the refrigerant passing through the orifice when reaching the porous body is reduced. Like that.

[0025] The refrigeration cycle apparatus according to the next invention comprises:
In the above invention, the porous body on the inlet side of the refrigerant and the porous body on the outlet side of the refrigerant have different shapes or sizes.

According to the present invention, the shape or size, for example, the diameter of the porous body on the inlet side and the porous body on the outlet side are changed so that the inlet and outlet of the refrigerant can be easily determined.

[0027] The refrigeration cycle apparatus according to the next invention comprises:
In the above invention, a groove is provided in an outer peripheral portion of the orifice holder into which the porous body is fitted.

According to the present invention, a groove is provided in an outer peripheral portion of a portion of the orifice holding body for fixing the porous body, in which the porous body is fitted. In addition to the above, even when burrs on the outer peripheral portion of the porous body fall off, the burrs that have fallen off are kept trapped in the grooves to prevent outflow into the refrigerant circuit.

[0029] The refrigeration cycle apparatus according to the next invention comprises:
In the above invention, a tapered portion is formed at the inlet side of the orifice, where the upstream side of the refrigerant is open.

According to the present invention, the tapered portion is provided on the inlet side of the orifice with respect to the flow of the refrigerant, and when the refrigerant passes through the orifice, the streamline of the refrigerant is smoothed by the tapered portion.

[0031] The refrigeration cycle apparatus according to the next invention comprises:
In the above invention, a curved surface portion having an opening on the upstream side of the refrigerant is formed on the inlet side of the orifice.

According to the present invention, the curved portion is provided on the inlet side of the orifice with respect to the flow of the refrigerant, and when the refrigerant passes through the orifice, the streamline of the refrigerant is further smoothed by the curved portion. .

[0033] The refrigeration cycle apparatus according to the next invention comprises:
In the above invention, a tapered portion having an opening on the downstream side of the refrigerant is formed on the outlet side of the orifice.

According to the present invention, a taper portion having an apex angle of about 120 degrees is provided on the outlet side of the orifice with respect to the flow of the refrigerant so that when the refrigerant passes through the orifice, the streamline of the refrigerant is smoothened. The spread angle of the refrigerant after passing through the orifice is increased, the flow velocity of the refrigerant upon reaching the porous body is reduced, and the refrigerant uniformly flows into the outlet-side porous body.

The refrigeration cycle apparatus according to the next invention is as follows.
In the above invention, the orifice structure including the porous body and the orifice holder is press-fitted into a copper pipe, and the throttle mechanism corresponds to a refrigerant pipe to which the throttle mechanism is connected. The copper tube has a structure in which openings at both ends are narrowed.

According to the present invention, the orifice structure including the porous body is press-fitted into the copper pipe to fix the orifice structure, and the copper pipe is connected to the refrigerant pipe by narrowing both ends of the copper pipe. And so on.

The refrigeration cycle apparatus according to the next invention is as follows:
In the above invention, the orifice structure is characterized in that a groove is formed in a circumferential direction of an outer periphery thereof.

According to the present invention, the groove 21 is provided all around the outer peripheral portion of the orifice structure, and when the porous body is fixed to the structure by caulking, the fixing jig is fixed to the groove. By pressing with a caulking jig, the inlet side and the outlet side can be individually caulked.

The refrigeration cycle apparatus according to the next invention is as follows:
In the above invention, the throttle mechanism portion is caulked from the outer shell of the copper tube all around corresponding to the groove of the orifice structure.

According to this invention, the orifice structure is fixed to the outer copper pipe without any gap by caulking the entire circumference from the outer shell of the copper pipe corresponding to the groove of the orifice structure. .

The refrigeration cycle apparatus according to the next invention is as follows.
In the above invention, the copper tube forming the outer shell of the throttle mechanism portion is characterized in that it has a structure tapered from the orifice structure toward the outlet side.

According to the present invention, the outlet side portion of the copper tube forming the outer shell of the orifice structure is tapered,
Pneumatic resonance in the inner space of the copper tube forming the outer shell is prevented.

The refrigeration cycle apparatus according to the next invention is as follows.
In the above invention, the porous body is a metal porous body.

According to the present invention, a porous metal body is used as the porous body, so that it is not necessary to prevent heat transfer by brazing when connecting the outer copper tube to the pipe.

The refrigeration cycle apparatus according to the next invention is as follows.
In the above invention, the metal porous body is formed of a nickel material.

According to the present invention, the rolling piston of the compressor is locked even when a nickel material is used as the metal porous body and, for example, burrs or the like flow out of the refrigerant circuit and flow into the compressor. It is possible to continue driving without any change.

[0047]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a refrigeration cycle apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.

Embodiment 1 FIG. 1 is a refrigerant circuit diagram illustrating an outline of an air conditioner according to Embodiment 1 of the present invention. Here, a second flow control device 6 is provided instead of the second flow control device 36 of the air conditioner shown in FIG.
The same components as those of the air conditioner shown in FIG. 13 are denoted by the same reference numerals. That is, the air conditioner shown in FIG. 1 includes a compressor 1, a four-way valve 2 as switching means for switching a refrigerant flow between a cooling operation and a heating operation, an outdoor heat exchanger 3, a first flow control device 4, First indoor heat exchanger 5,
It has a second flow control device 6 and a second indoor heat exchanger 7, and each component constitutes a refrigeration cycle sequentially connected by piping. R410A which is a mixed refrigerant of R32 and R125 is used as a refrigerant of the refrigeration cycle, and an alkylbenzene-based oil is used as a refrigeration oil.

FIG. 2 is a refrigeration circuit diagram showing a detailed configuration of the second flow control device 6. In the second flow control device 6, the capillary tube 9 and the throttle mechanism unit 10 are connected in series, and the capillary tube 9 and the throttle mechanism unit 10 connected in series are connected in parallel to the two-way valve 8.

FIG. 3 is a view showing a detailed configuration of the orifice structure 10a used in the throttle mechanism section 10. FIG. 3A is a front view of the orifice structure 10a, and FIG. () Is a left side sectional view of the orifice structure 10a. In FIG. 3, the orifice structure 10a
The inlet-side porous body 13 and the outlet-side porous body 14 are arranged before and after the orifice 12. The porous body of the inlet-side porous body 13 and the outlet-side porous body 14 is entirely formed of a porous permeable material, and has an average diameter of vent holes, that is, pores on the surface and inside of the porous body through which a fluid can pass, of about 500 μm. , Porosity is 92 ± 6%. This porous body is obtained by applying a metal powder to urethane foam, heat-treating the urethane foam to burn it off, and molding the metal into a three-dimensional lattice. The material is Ni (nickel). In order to increase the strength of the porous body, Cr (chromium) may be plated or permeated.

Here, the refrigeration cycle operation during the dehumidifying operation of the air conditioner shown in FIG. 1 will be described with reference to the pressure-enthalpy diagram shown in FIG. In addition,
During the dehumidifying operation, the two-way valve 8 of the second flow control device 6 is in the closed state.

First, during the dehumidifying operation, the high-temperature and high-pressure vapor refrigerant (point A) that has exited from the compressor 1 that is operating at a speed corresponding to the load of the air conditioner passes through the four-way valve 2 and is The heat exchanger 3 exchanges heat with the outside air, condenses, and becomes a gas-liquid two-phase refrigerant (point B). The high-pressure two-phase refrigerant is slightly depressurized by the first flow control device 4, becomes an intermediate-pressure gas-liquid two-phase refrigerant, and flows into the first indoor heat exchanger 5 (point C). The intermediate-pressure gas-liquid two-phase refrigerant that has flowed into the first indoor heat exchanger performs heat exchange with indoor air and further condenses (point D). The gas-liquid two-phase refrigerant flowing out of the first indoor heat exchanger flows into the second flow control device 6.

Since the two-way valve 8 of the second flow control device 6 is in the closed state, the refrigerant passes through the capillary tube 9 and flows through the throttle mechanism 1.
Flow into 0. The refrigerant flowing into the expansion mechanism 10 is decompressed by the orifice 12, becomes a low-pressure gas-liquid two-phase refrigerant, and flows into the second indoor heat exchanger 7 (point E). The thickness of each of the inlet-side porous body 13 and the outlet-side porous body 14 provided at the entrance of the orifice 12 is about 3 mm. The inner diameter of the orifice 12 is 1 mm, and the thickness (length) is about 3 mm. The refrigerant flowing into the second indoor heat exchanger 7 evaporates by removing the sensible heat and latent heat of the indoor air. The low-pressure steam refrigerant that has exited the second indoor heat exchanger 7 returns to the compressor 1 via the four-way valve 2 again. The indoor air is heated by the first indoor heat exchanger 5 and cooled and dehumidified by the second indoor heat exchanger 7, so that the room air is dehumidified while preventing the room temperature from lowering.

Here, in the ordinary orifice type flow rate control device, when the gas-liquid two-phase refrigerant passes, a large refrigerant flow noise is generated around the throttle. In particular, when the flow mode of the gas-liquid two-phase refrigerant is a slag flow, a large refrigerant flow noise is generated upstream of the throttle. The cause is that when the flow mode of the gas-liquid two-phase refrigerant is a slag flow, the vapor refrigerant flows intermittently in the flow direction, and large steam slag or vapor bubbles pass through the throttle flow path by the throttle flow path. This is because the steam slag or vapor bubbles upstream of the throttle flow path collapse, causing them to vibrate.In addition, since the vapor refrigerant and the liquid refrigerant pass through the throttle alternately, the speed of the refrigerant is This is because the pressure is high when the refrigerant passes and low when the liquid refrigerant passes, so that the pressure upstream of the throttle portion also fluctuates accordingly. In addition, at the exit of the conventional second flow control device 36,
Since there are one to four outlet flow paths, the flow rate of the refrigerant is high, and high-speed gas-liquid two-phase flow occurs at the outlet, and the refrigerant collides with the wall surface. appear. In addition, turbulence and vortices generated by the high-speed gas-liquid two-phase jet at the outlet portion increase jet noise.

On the other hand, as shown in FIG. 5, in the second flow control device 6 according to the first embodiment, the refrigerant flowing out of the first indoor heat exchanger 5 is input from the inlet 6a, When the valve 8 is open, it flows through the two-way valve 8 to the outlet 6b, flows out to the second indoor heat exchanger 7, and when the two-way valve 8 is closed, the capillary 9 and flows into the throttle mechanism 10 and then to the outlet 6b.
And flows out to the second indoor heat exchanger 7.

In the second flow control device 6, the gas-liquid two-phase refrigerant is mixed by the capillary tube 9, the mixed gas-liquid two-phase refrigerant flows into the throttle mechanism 10, and the inlet-side porous body 13 The vapor slag (large bubbles) becomes small bubbles by passing through a myriad of microscopic air holes, and the refrigerant flows in a homogeneous gas-liquid two-phase flow (a state in which the vapor refrigerant and the liquid refrigerant are well mixed. ), The vapor refrigerant and the liquid refrigerant pass through the orifice 12 at the same time, and the speed of the refrigerant does not fluctuate and the pressure does not fluctuate. In addition, the inlet-side porous body 13
Such a porous permeable material as described above has a complicated internal flow path, in which pressure fluctuations are repeated, and there is an effect that the pressure fluctuations are partly converted into heat energy, thereby making the pressure fluctuation constant. This has the effect of absorbing pressure fluctuations even if they occur, making it difficult to convey the effects upstream. In the high-speed gas-liquid two-phase jet downstream of the orifice 12, the outlet-side porous body 14 sufficiently reduces the flow velocity of the refrigerant inside the outlet-side porous body 14, and the velocity distribution is uniform.
Since the high-speed gas-liquid two-phase jet does not collide with the wall surface and no large vortex is generated in the flow, jet noise is also reduced.

Here, the detailed configuration of the orifice structure 10a will be described. As shown in FIG. 3, the orifice structure 10a has an orifice 12 formed in the center of an orifice holder 11, and a substantially disk-shaped orifice holder 11a.
The porous body 13 on the inlet side and the porous body 14 on the outlet side
To form a sandwiched structure. This sandwich structure is formed by the caulking portion 1 of the orifice holder 11.
5, the orifice holder 11 and the inlet-side porous body 1
3 and the peripheral part with the outlet side porous body 14 are caulked and fixed.

Further, spaces 16 and 17 are provided between the inlet-side porous body 13 and the outlet-side porous body 14 and the orifice 12. By providing the spaces 16 and 17, the flow path between the inlet-side porous body 13 and the outlet-side porous body 14 and the orifice 12 can be widened.
Even when foreign matter is deposited on a part of the mesh of the inlet-side porous body 13 and the outlet-side porous body 14, the risk of clogging is avoided because a plurality of flow paths exist in other porous body parts. You.

Then, the inlet side porous body 13 and the orifice 1
By setting the distance 16a of the space 16 between the inlet side porous body 1 and the orifice 12 to 1 mm, the distance 16a is
In order to prevent the bubbles miniaturized in Step 3 from re-aggregating and becoming bubbles larger than the diameter φ1 mm of the orifice 12, fluctuation in pressure is suppressed while avoiding the risk of clogging.

Since the refrigerant having passed through the orifice 12 diffuses in a conical shape, the outlet side porous body 14 and the orifice 1
By setting the distance 17a of the space 17 between the two to 2 mm, which is 1 mm or more in diameter of the orifice 12, when the refrigerant passing through the orifice 12 reaches the outlet-side porous body 14, the flow velocity of the refrigerant is reduced. become. Due to the decrease in the flow velocity, sand erosion of the porous mesh that occurs when the refrigerant contains fine metal powder or the like is suppressed.

Here, the distance 16 with respect to the orifice 12
When the distance a is different from the distance 17a, when the orifice structure 10a is incorporated in the refrigerant circuit, it is necessary to ensure that the mounting direction is correct. For this reason, as shown in FIG. 3, the direction of the entrance can be determined by changing the diameter of the entrance-side porous body 13 and the exit-side porous body 14. Specifically, by setting the inlet-side porous body 13 to have a diameter of 20 mm and the outlet-side porous body 14 to have a diameter of 21 mm, the worker can assemble the inlet-side porous body 13 with a diameter of 21 mm.
Or the outlet side porous body 14 can be easily determined. Further, by changing the diameter of the inlet-side porous body 13 and the outlet-side porous body 14, when different materials are used as the porous body material of the inlet-side porous body 13 and the outlet-side porous body 14, the porous body to be attached is changed. Misuse can be prevented.

Further, as shown in FIG. 3, the inner peripheral portion of the caulking portion 15 of the orifice holder 11
5, a groove 21 is provided in a portion where the outer peripheral portion of the porous body into which the inlet-side porous body 13 and the outlet-side porous body 14 are fitted is in contact. When the inlet-side porous body 13 and the outlet-side porous body 14 are punched in a circular shape, sagging occurs on the outer peripheral portion. Therefore, when the inlet-side porous body 13 and the outlet-side porous body 14 are directly placed on the outer peripheral plane of the orifice holder 11, It rises from the plane by the amount of dripping. As a result, there is a possibility that the distance between the caulking portion 15 and the peripheral portions of the inlet-side porous body 13 and the outlet-side porous body 14 cannot be stably obtained. Here, the groove 21
But, this burr is accommodated and the entrance side porous body 13 and the exit side porous body 14 are prevented from rising. The depth of the groove 21 is
It is about 0.1 mm to 0.3 mm. Further, even when burrs fall off from the peripheral portions of the inlet-side porous body 13 and the outlet-side porous body 14, the fallen burrs are still captured in the grooves 21, so that the burrs fall on the refrigerant circuit. The outflow is prevented, and the clogging of the refrigerant circuit components due to the outflow of the dropped burrs is prevented.

As shown in FIG. 3, the orifice 12
A 0.3R curved surface 18 corresponding to the diameter of the orifice 12 of 1 mm is formed on the inlet side of the orifice 12. By forming the curved surface 18, the streamline of the refrigerant passing through the orifice 12 is smoothly bent. As a result, generation of a vortex after the orifice 12 passes through the entrance is suppressed, foreign matter is prevented from adhering to the inner wall of the orifice 12, and generation of fluid noise is also suppressed.

As shown in FIG. 6, the orifice 12
A 0.3C taper 20 corresponding to the diameter of the orifice 12 of 1 mm may be formed on the inlet side of the orifice 12.
Also by forming this taper 20, the streamline of the refrigerant passing through the orifice 12 is smoothly bent, the generation of vortices after passing through the inlet of the orifice 12 is suppressed, and the adhesion of foreign matter to the inner wall of the orifice 12 is suppressed. You. Since the shape of the taper 20 is simpler than that of the curved surface 18 in which an R shape is formed by cutting, the processing cost can be reduced.

Further, the vertex angle 12
By forming the taper 19 of about 0 degrees, the streamline of the refrigerant can be smoothed and the divergence angle of the refrigerant after passing through the orifice 12 can be increased. As a result, the flow rate of the refrigerant when reaching the outlet-side porous body 14 can be reduced, and the refrigerant uniformly flows into the outlet-side porous body 14, so that the flow rectifying effect of the outlet-side porous body 14 is further enhanced. Can be enhanced. Also, the apex angle is 12
By setting the angle to about 0 °, a drill can be used at the time of taper processing, and the processing can be easily performed by using the tip, so that the processing cost can be suppressed.

Here, the detailed structure of the throttle mechanism 10 including the orifice structure 10a will be described. As shown in FIG. 3, the inlet-side porous body 13 and the outlet-side porous body 14 are fixed to the orifice holder 11 by caulking all around by the caulking part 15. As shown in FIG. 6, the entire circumference of the orifice holder 11 is fixed to the inlet-side porous body 1 at the inner peripheral planes at both ends of the orifice holder 11 before caulking.
3 and the outlet side porous body 14 are inserted, and a caulking jig 24,
By compressing 25 from both ends in the direction of the arrow, the caulking portion 15 performs the entire circumference caulking, and the inlet-side porous body 13 and the outlet-side porous body 14 are fixed to the orifice holding body 11 without any circumferential clearance, and the orifice structure The body 10a is formed. As a result, burrs are generated when the porous bodies of the inlet-side porous body 13 and the outlet-side porous body 14 are punched out, and the burrs are prevented from flowing into the refrigerant circuit even when the porous body is assembled while being attached to the outer peripheral portion of the porous body. Is done. In addition, the inlet-side porous body 13 and the outlet-side porous body 14 are pressed only by the orifice holder 1.
1, the orifice structure 10a can be formed, so that the manufacturing cost can be reduced.

As shown in FIG. 8, the orifice structure 10a formed as described above is fixed in the copper tube 26 by being press-fitted from the inlet side of the flow of the refrigerant in the copper tube 26. The ends 27 and 28 of 26 are squeezed and narrowed, and formed into a shape for connecting the refrigerant pipe. Thus, the aperture mechanism 10 is formed. The press-fitting allowance between the outer diameter of the orifice structure 10a and the inner diameter of the copper pipe, which is press-fitted into the expansion mechanism 10, is about 25 μm. Orifice structure 1 even when pressure is applied
0a does not move toward the exit side. In addition, by forming the outer shell with a copper tube, the drawing mechanism 1
The outer shell of 0 can be constructed at low cost.

Here, as shown in FIG. 3, the orifice structure 10a has a width of 2 m over the entire outer periphery thereof.
A groove 22 having a depth of 1.5 mm is provided. This groove 22
As shown in FIG. 7, when the inlet-side porous body 13 and the outlet-side porous body 14 are fixed to the orifice holder 11 by caulking, the groove 22 engages with the fixing jig 23 and functions as a stopper. . And caulking jigs 24, 25
By pressing the orifice structure 10a, the inlet-side porous body 13 and the outlet-side porous body 14 are individually caulked, and a stable caulked shape can be obtained.

FIG. 9 shows the second flow control device 6 and the second conventional flow control device.
FIG. 3 is a diagram illustrating frequency characteristics of noise generated by a flow control device. The frequency characteristics of noise shown in FIG. 9 indicate measurement results, the horizontal axis indicates frequency [Hz], and the vertical axis indicates sound pressure (SP
L) [dBA]. In FIG. 9, the solid line indicates the measurement result of the second flow control device 6 shown in the first embodiment, and the broken line indicates the measurement result of the conventional second flow control device 36 shown in FIG. ing. From the frequency characteristics of the second flow control device 6 indicated by the solid line, it can be seen that the sound pressure level is reduced over the entire frequency range as compared with the frequency characteristics of the conventional second flow control device 36. In particular, it can be seen that a significant noise reduction effect is obtained in the range of 2000 Hz to 7000 Hz that is well heard by human ears.

When it is necessary to set the inlet side pipe of the throttle mechanism section 10 to have a vertically rising flow by arranging the pipes of the air conditioner, if ordinary pipes are used, the refrigerant becomes gas-liquid two-phase in the rising pipe. The gas and the liquid are separated and flow discontinuously into the throttle mechanism unit 10 and cause a pressure fluctuation. However, in the vertical rising pipe formed by the capillary tube 9 as shown in FIG. As a result, the generation of the refrigerant noise is also suppressed.

Embodiment 2 Next, a second embodiment of the present invention will be described. In the first embodiment described above,
As shown in FIG. 5, the throttle mechanism unit 10 is set vertically so that the flow of the refrigerant is vertical. However, in the second embodiment,
The aperture mechanism 10 is installed horizontally. In this case, the configuration of the capillary tube 9 provided on the upstream side of the throttle mechanism 10 is omitted.

In FIG. 10, the throttle mechanism 10 is arranged horizontally, and the flow of the refrigerant in the throttle mechanism 10 is horizontal. The vapor slag (bubbles) of the two-phase refrigerant flowing into the space 31 on the inlet side of the expansion mechanism 10 by the slag flow rises to the upper part of the space 31 and the liquid phase accumulates at the lower part of the space 31 and is separated. During a normal dehumidifying operation, the portion of the orifice 12 becomes a liquid phase, and fine bubbles that pass through the inlet-side porous body 13 pass through the orifice 12 continuously, so that pressure fluctuations occur. It is suppressed, and the generation of the refrigerant noise is also suppressed.

Embodiment 3 Next, a third embodiment of the present invention will be described. In the third embodiment, FIG.
As shown in FIG. 1, a caulking portion 29 is provided along the groove 22 provided on the entire periphery of the outer peripheral portion of the orifice structure 10a, and on the entire periphery of the copper tube 26 of the outer shell corresponding to the groove 22. . The orifice structure 10a is connected to the outer shell copper tube 26 without any gap.
The refrigerant can be prevented from passing through portions other than the orifice 12, and stable throttle characteristics can be obtained.

Embodiment 4 Next, a fourth embodiment of the present invention will be described. In the fourth embodiment, FIG.
As shown in FIG. 2, a taper portion 30 in which the outlet side portion of the copper tube 26 forming the outer shell of the expansion mechanism portion 10 has a tapered shape.
Is formed. That is, along the flow of the refrigerant flowing through the copper tube 26, the tapered portion 3 in which the outlet side portion is sequentially narrowed.
0 is provided. Thereby, pneumatic resonance in the inner space of the outer copper tube 26 is prevented, and the generation of peak sound can be suppressed.

Embodiment 5 FIG. Next, a fifth embodiment of the present invention will be described. In the fifth embodiment, the porous bodies of the entrance-side porous body 13 and the exit-side porous body 14 are metal porous bodies. When the porous bodies of the inlet-side porous body 13 and the outlet-side porous body 14 are made of resin, the outer copper pipe 26
When performing brazing to connect to the piping, cooling of the porous body is indispensable, but by making the porous body a metal porous body, the effect of heat due to brazing can be ignored, and brazing can be ignored. Work becomes easy.

In particular, nickel (Ni) is used as the metal porous body.
It is preferable to use This is because even if porous burrs flow out into the refrigerant circuit and flow into the compressor 1, nickel is softer than iron forming the cylinder of the compressor 1, so that the rolling of the compressor 1 is performed. This is because the operation can be continued without locking the piston.

[0077]

As described above, according to the present invention, the gas-liquid two-phase refrigerant is mixed by the capillary and flows into the throttle mechanism, and passes through the porous body having numerous and minute air holes. As a result, the refrigerant vapor slag and the refrigerant bubbles become small bubbles, and the refrigerant flows into a homogeneous gas-liquid two-phase state, preventing the collapse of the refrigerant vapor slag and the refrigerant bubbles. Does not cause fluctuations in the refrigerant velocity due to simultaneous passage of the refrigerant, and eliminates pressure fluctuations.Furthermore, due to the complicated flow path inside the porous body, pressure fluctuations of the refrigerant are repeated inside the porous body, and part of the refrigerant is converted into heat energy. In addition, since the pressure fluctuation is made constant, there is an effect that generation of the refrigerant flow noise can be suppressed and noise can be significantly reduced.

According to the next invention, by connecting a capillary tube that does not cause gas-liquid separation to the inlet side of the throttle mechanism, generation of refrigerant flow noise is prevented regardless of the arrangement of the throttle mechanism. Therefore, there is an effect that the noise can be greatly reduced and the flexibility of the device configuration can be provided.

According to the next invention, when the refrigerant passes through the orifice in which the flow of the refrigerant is in the horizontal direction, the vapor slug of the two-phase refrigerant rises above the front space of the inlet-side porous body in the throttle mechanism. The liquid phase accumulates and separates in the lower part, but as it passes through the porous body, the vapor slag becomes fine bubbles and passes through the orifice, suppressing pressure fluctuations. This has the effect of reducing noise.

According to the next invention, since the porous body is fixed to the orifice holder by the entire circumference caulking by the caulking portion, even when the outer peripheral portion of the porous body has burrs, the entire circumference is caulked. Since the burrs can be prevented from flowing out onto the refrigerant circuit, it is possible to prevent clogging of components in the refrigerant circuit.

According to the next invention, by providing a space between the orifice and the porous body, the flow path between the porous body and the orifice can be widened, and foreign matter is deposited on a part of the mesh of the porous body. Even in this case, since a plurality of flow paths are made effective and clogging of the refrigerant is avoided, there is an effect that danger of clogging of the refrigerant can be avoided.

According to the next invention, the distance of the space provided between the orifice and the porous body on the inlet side of the refrigerant is made smaller than the diameter of the orifice. To prevent the formation of large bubbles that exceed the diameter of the orifice, and to prevent the risk of clogging while suppressing the occurrence of pressure fluctuations. There is an effect that it can be significantly reduced.

According to the next invention, the distance of the space formed between the porous body on the outlet side and the orifice is equal to or larger than the diameter of the orifice, and the flow rate of the refrigerant passing through the orifice when reaching the porous body is reduced. Therefore, there is an effect that erosion of the skeleton of the porous body, which is generated when the refrigerant contains fine metal powder or the like, can be prevented.

According to the next invention, the shape or size, for example, the diameter of the porous body on the inlet side and the porous body on the outlet side are changed so that the inlet and outlet of the refrigerant can be easily determined. It is possible to prevent misuse such as incorrect assembly of the porous body and incorrect orientation of the orifice structure with the porous body when the porous body on the side and the porous body on the outlet side are formed of different materials. It has the effect of being able to.

According to the next invention, a groove is provided in an outer peripheral portion of a portion of the orifice holding body for fixing the porous body, in which the porous body is fitted.
In addition to preventing the porous body from floating, even if burrs on the outer peripheral part of the porous body fall off, the dropped burrs are kept trapped in the groove to prevent outflow to the refrigerant circuit. The effect is obtained that the body can be securely fixed to the orifice holding body, and that the refrigerant circuit components can be prevented from being clogged by the outflow of the burrs that have fallen off.

According to the next invention, a tapered portion is provided on the inlet side of the orifice with respect to the flow of the refrigerant, and when the refrigerant passes through the orifice, the streamline of the refrigerant is smoothed by the tapered portion. Therefore, there is an effect that foreign substances can be prevented from adhering to the inner wall of the orifice.

According to the next invention, a curved portion is provided on the inlet side of the orifice with respect to the flow of the refrigerant, and when the refrigerant passes through the orifice, the curved line of the refrigerant is further smoothed by the curved portion. Therefore, it is possible to prevent foreign matter from adhering to the inner wall of the orifice and to suppress generation of fluid noise.

According to the next invention, a taper portion having an apex angle of, for example, about 120 degrees is provided on the outlet side of the orifice with respect to the flow of the refrigerant so that the refrigerant flows smoothly when the refrigerant passes through the orifice. At the same time, the divergence angle of the refrigerant after passing through the orifice is increased, the flow velocity of the refrigerant when reaching the porous body is reduced, and the refrigerant is allowed to uniformly flow into the porous body on the outlet side. The flow rectification effect of the porous body can be further enhanced, and the effect of suppressing the generation of refrigerant flow noise can be obtained.

According to the next invention, the orifice structure including the porous body is press-fitted into the copper pipe to fix the orifice structure, and the copper pipe is connected by narrowing both ends of the copper pipe to make it narrow. Since the shape is formed, the drawing mechanism portion can be easily formed by simple processing, and as a result, there is an effect that cost reduction can be realized.

According to the next invention, a groove 21 is provided over the entire outer peripheral portion of the orifice structure, and when the porous body is fixed to the structure by caulking, a fixing jig is fixed to the groove. ,
By pressing with a caulking jig, the inlet and outlet sides can be caulked individually.
A stable crimped shape can be obtained, and at the time of transporting the orifice structure, by fitting the groove into the rail, the porous body can be transported without contacting another object.

According to the next invention, the orifice structure is fixed to the outer copper tube without gaps by caulking the entire circumference from the outer shell of the copper tube corresponding to the groove of the orifice structure. Therefore, it is possible to reliably prevent the refrigerant from passing through portions other than the orifice in the throttle mechanism, and it is possible to obtain an effect that stable throttle characteristics can be obtained.

According to the next invention, the outlet side of the copper tube forming the outer shell of the orifice structure is tapered so as to prevent air injection resonance in the inner space of the copper tube forming the outer shell. Therefore, it is possible to suppress the generation of the peak sound.

According to the next invention, a metal porous body is used as the porous body, so that it is not necessary to prevent heat transfer by brazing when connecting the outer copper pipe to the pipe. The effect that brazing work becomes easy is produced.

According to the next invention, as the porous metal body,
High reliability because nickel material is used so that even if burrs etc. flow out into the refrigerant circuit and flow into the compressor, operation can be continued without locking the rolling piston of the compressor. This has the effect that a refrigeration cycle device having the following characteristics can be obtained.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram illustrating a configuration of an air conditioner according to Embodiment 1 of the present invention.

FIG. 2 is a refrigerant circuit diagram showing a configuration of a second flow control device shown in FIG.

FIG. 3 is a diagram showing a configuration of an orifice structure in a throttle mechanism shown in FIG. 2;

FIG. 4 is a pressure-enthalpy diagram illustrating a refrigeration cycle during a dehumidifying operation of the air conditioner illustrated in FIG.

FIG. 5 is a diagram illustrating a configuration of a second flow control device illustrated in FIG. 1;

FIG. 6 is a diagram showing a configuration of another example of the orifice structure shown in FIG. 3;

FIG. 7 is an explanatory view illustrating press working of the orifice structure shown in FIG. 3;

8 is a diagram showing a detailed configuration of a diaphragm mechanism shown in FIG.

9 is a diagram showing frequency characteristics of noise of the second flow control device shown in FIG. 1 and a conventional second flow control device.

FIG. 10 is a diagram showing a configuration of a second flow control device of the air conditioner according to Embodiment 2 of the present invention.

FIG. 11 is a diagram showing a configuration of a throttle mechanism of an air conditioner according to Embodiment 3 of the present invention.

FIG. 12 is a diagram showing a configuration of a throttle mechanism of an air conditioner according to Embodiment 4 of the present invention.

FIG. 13 is a refrigerant circuit diagram showing a configuration of a conventional air conditioner.

[Explanation of symbols]

1 compressor, 2 four-way valve, 3 outdoor heat exchanger, 4 first
Flow control device, 5 first indoor heat exchanger, 6 second flow control device, 6a inlet section, 6b outlet section, 7 second indoor heat exchanger, 8 two-way valve, 9 capillary tube, 10 throttle mechanism section, 10a orifice Structure, 11 orifice holder, 12 orifice, 13 inlet side porous body, 14 outlet side porous body, 15, 29 caulked portion, 16, 17, 31
Space, 16a, 17a distance, 18 curved surface, 19, 2
0 taper, 21, 22 groove, 23 fixing jig, 2
4,25 caulking jig, 26 copper tube, 27, 28 end, 30 taper.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoru Hirakuni 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Electric Corporation (72) Inventor Atsushi Mochizuki 2-5-2, Otemachi, Chiyoda-ku, Tokyo No. Mitsubishi Electric Engineering Co., Ltd.

Claims (18)

[Claims] An orifice connected in series with the capillary and having an orifice sandwiched between porous bodies provided on an inlet side and an outlet side with respect to a flow of a refrigerant; A two-way valve connected in parallel to the capillary tube and the throttle mechanism, and a flow control unit comprising: a first indoor heat exchanger and a second indoor heat exchanger. Refrigeration cycle equipment. 2. The method according to claim 1, wherein the capillary and the throttle mechanism are disposed substantially vertically along a flow direction of the refrigerant, and the refrigerant flowing through the capillary flows vertically upward from below.
2. The refrigeration cycle apparatus according to claim 1, wherein the refrigerant flowing through the throttle mechanism flows vertically downward. 3. A flow control comprising: a two-way valve; and a throttle mechanism connected in parallel with the two-way valve and having an orifice sandwiched between porous bodies provided on the inlet and outlet sides of the refrigerant. A refrigeration cycle, wherein the cooling mechanism is disposed between the first indoor heat exchanger and the second indoor heat exchanger, and the throttle mechanism is disposed substantially horizontally along a flow direction of the refrigerant. apparatus. 4. The throttle mechanism section according to claim 1, wherein the porous body is fixed by a caulking section provided on a peripheral portion of an orifice holding body forming the orifice. A refrigeration cycle apparatus according to item 1. 5. The refrigeration cycle apparatus according to claim 1, wherein a space is formed between the orifice and the porous body. 6. The refrigeration system according to claim 5, wherein a distance in the refrigerant flow direction of the space formed between the orifice and the porous body on the refrigerant inlet side is equal to or less than a diameter of the orifice. Cycle equipment. 7. The orifice according to claim 5, wherein a distance between the orifice and the porous body on the outlet side of the refrigerant in the refrigerant flow direction is equal to or larger than a diameter of the orifice. Refrigeration cycle equipment. 8. The refrigeration according to claim 1, wherein the porous body on the inlet side of the refrigerant and the porous body on the outlet side of the refrigerant have different shapes or sizes. Cycle equipment. 9. The refrigeration cycle apparatus according to claim 4, wherein a groove is provided on an outer peripheral portion of the orifice holder into which the porous body is fitted. 10. The refrigeration cycle apparatus according to claim 1, wherein a tapered portion whose upstream side is open is formed at the inlet of the orifice. 11. The refrigeration cycle apparatus according to claim 1, wherein a curved surface portion in which an upstream side of the refrigerant is opened is formed at an inlet side of the orifice. 12. The refrigeration cycle apparatus according to claim 1, wherein a tapered portion whose downstream side is open is formed at the outlet side of the orifice. 13. An orifice structure comprising the porous body and the orifice holder is press-fitted into a copper pipe, and the throttle mechanism corresponds to a refrigerant pipe to which the throttle mechanism is connected. The refrigeration cycle apparatus according to any one of claims 1 to 12, wherein the copper pipe has a structure in which openings at both ends are narrowed. 14. The orifice structure according to claim 13, wherein a groove is formed in a circumferential direction of an outer periphery of the orifice structure.
A refrigeration cycle apparatus according to item 1. 15. The refrigeration cycle apparatus according to claim 14, wherein the expansion mechanism is caulked all around the outer periphery of the copper tube corresponding to the groove of the orifice structure. 16. The copper tube forming the outer shell of the throttle mechanism has a structure tapered from the orifice structure toward an outlet side.
A refrigeration cycle apparatus according to any one of claims 15 to 15. 17. The refrigeration cycle apparatus according to claim 1, wherein the porous body is a metal porous body. 18. The refrigeration cycle apparatus according to claim 17, wherein the porous metal body is formed of a nickel material.