JPH11351706A - Refrigerant distributor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the occurrence of hydrodynamic self excitation sound by raising the distribution performance of a refrigerant. SOLUTION: This is a refrigerant circulating device comprising a compressor, a condenser, a depressurizer, a distributor 5, etc., and this is equipped with a inflow part 7 into which a gas-liquid two-phase flow flows, a taper space part which widens in the direction of downstream, being positioned downstream of the inflow part 7, a wide space part which has a refrigerant collision part 15, being positioned downstream of the taper space part, an orifice part 20 which has an orifice hole 2 and is thick in the direction of flow of the wide space part and also demarcates the wide space part into a first agitation space part 16 including the taper space part and a second agitation space part 17 including the refrigerant collision part 15, and an outflow part 13 which lets a homogeneous flow flow out, being positioned downstream of the wide space part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant distributor disposed in a refrigerant circulating device such as an air conditioner, and more particularly, to an orifice having a thickness, an R-shaped opening, The present invention relates to a refrigerant distributor configured to suppress the generation of mechanical self-excited sound.

FIG. 4 is a longitudinal sectional view showing an example of a conventional refrigerant distributor provided in a refrigerant circulation device. The high-pressure refrigerant gas compressed by the compressor provided in the refrigerant circulation device is sent to the condenser after passing through the four-way switching valve, where all the refrigerant is liquefied while being deprived of heat, and passes through the decompressor to evaporate. It becomes a liquid two-phase flow and passes through the distributor of the distributor 30.

[0003] By the way, the gas-liquid two-phase flow that has passed through the decompressor often becomes deflected under the influence of centrifugal force at the bent portion when passing through the refrigerant pipe. Therefore, the flow rate of the refrigerant flowing from the inflow pipe 7 of the distributor 30 is reduced in the widened connection pipe 9 to reduce the influence of the drift. Further, the flow is increased by reducing the flow rate in the orifice hole 32 of the orifice plate 31 to form a spray-like homogeneous flow, and is then uniformly distributed to the outflow pipe 13 through the plurality of outflow portions 14.

[0004]

According to the distributor 30 configured as described above, the hydrodynamic self-exciting sound is generated when the compressor is operated at a low frequency, that is, when the refrigerant circulation amount is low. Since the self-excited sound has a low refrigerant circulation amount, it does not become a spray flow even in a gas-liquid two-phase flow and the gas-liquid is separated, so that the Karman gas flows out from the orifice hole 32 of the orifice plate 31 A vortex is generated, and the frequency of the Karman vortex coincides with the resonance frequency of the distributor 30 and is generated self-excitingly. The frequency of the vortex shedding of the Karman vortex street is determined by the inner diameter of the orifice plate 31 and the flow rate of the gas phase, that is, the amount of circulating refrigerant. Therefore, when the inner diameter of the orifice plate 31 is determined, when the refrigerant circulation amount reaches a certain value, that is, when the flow rate of the gas phase reaches a certain value, the frequency of the Karman vortex Coincides with the resonance frequency of the distributor 30, and a self-excited sound is generated.

[0005] Even when self-excited sound is not generated at the compressor operating frequency during normal operation, the amount of circulating refrigerant gradually decreases after the compressor is stopped, and the frequency of the Karman vortex is reduced by the resonance frequency of the distributor 30. When the amount of the circulating refrigerant reaches a value that coincides with the above, a self-excited sound may be generated for a short time. In particular, when a hydrofluorocarbon-based refrigerant (R410A) is used as the refrigerant, the self-excited sound occurs frequently because the refrigerant density is large, and the flow velocity is reduced at the same refrigerant circulation amount, so that gas-liquid is easily separated. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a refrigerant distributor capable of improving the refrigerant distribution performance and suppressing the generation of a hydrodynamic self-excited sound. Aim.

[0007]

SUMMARY OF THE INVENTION The present invention provides a compressor for compressing a refrigerant gas into a high-pressure refrigerant gas, a condenser for converting the high-pressure refrigerant gas into a liquefied refrigerant, and a decompressor for converting the liquefied refrigerant into a gas-liquid two-phase flow. A refrigerant circulation device comprising a refrigerant distributor or the like that makes a gas-liquid two-phase flow a homogeneous flow and flows out, wherein an inflow part into which the gas-liquid two-phase flow flows, and a downstream direction located downstream of the inflow part A widened space portion having a refrigerant impingement portion located downstream of the tapered space portion, and a orifice hole having a thickness in the flow direction of the widened space portion and a widened space portion formed into a tapered space. An orifice section partitioned into a first stirring space section including a section and a second stirring space section including a refrigerant collision section, and an outflow section which is located downstream of the widening space section and flows out a homogeneous flow. .

In addition, an orifice portion having a taper is provided upstream of the orifice hole. Further, an orifice portion having a taper is provided downstream of the orifice hole. Further, an orifice portion having a taper is provided on both the upstream side and the downstream side of the orifice hole. Further, an orifice portion having an R-shaped taper on both the upstream and downstream sides of the orifice hole and having a smooth structure near the center in the flow direction of the orifice hole is provided. In addition, a cutout portion having a depth corresponding to the thickness of the inflow portion was provided at the downstream end of the inflow portion.

[0009]

Embodiment 1 FIG. 1 is a schematic view showing a refrigerant circulating apparatus according to Embodiment 1 of the present invention, and FIG. 2 is a longitudinal sectional view of a main part of FIG. 1 is a compressor for compressing the refrigerant gas, 2 is a four-way switching valve for switching the flow direction of the refrigerant, 3 is a condenser for condensing and liquefying the high-pressure refrigerant gas sent from the compressor 1, and 3a is provided for the condenser 3. A cooling fan, 4 a decompressor for converting the refrigerant liquefied in the condenser 3 into a gas-liquid two-phase flow, 5 a refrigerant distributor, and 6 an evaporator with a fan, which are sequentially connected by refrigerant piping. Further, the refrigerant pipe on the downstream side of the compressor 1 and the refrigerant pipe on the downstream side of the evaporator 6 are in contact via the four-way switching valve 2.

Next, the refrigerant distributor 5 provided in the refrigerant circulation device will be described in detail with reference to FIG. Reference numeral 7 denotes an inflow pipe into which the refrigerant in the gas-liquid two-phase flow flows, and reference numeral 8 denotes a downstream end of the inflow pipe 7. Reference numeral 9 denotes a substantially funnel-shaped connection pipe having one end concentrically attached to the inflow pipe 7 so as to reduce the speed of the refrigerant flowing into the inflow pipe 7 so as to reduce the flow deviated by the refrigerant pipe. The connecting pipe 9 includes a reduced diameter portion 9a, an increased diameter portion 9b, and a tapered portion 9c. The inner diameter of the reduced diameter portion 9a is substantially equal to the outer diameter of the inflow pipe 7, and the diameter of the increased diameter portion 9b is reduced. The diameter of the diameter portion 9a is larger than that of the diameter portion 9a, and the taper portion 9c disposed therebetween gradually widens the diameter from the reduced diameter portion 9a to the increased diameter portion 9b. Thus, the downstream end 8 of the inflow pipe 7 is inserted into the reduced diameter portion 9a of the connection pipe 9, positioned by the stopper 10, and brazed.

Reference numeral 11 denotes a main body pipe attached to the enlarged-diameter portion 9b side of the connecting pipe 9, which is disposed concentrically with the inflow pipe 7, and has a widened stepped portion along the circumference of the inner surface near the end on the connecting pipe 9 side. A plurality of outlet pipes (capillary tubes) 11a are provided, the inner diameter of which is substantially equal to the outer diameter of the enlarged diameter portion 9b of the connection pipe 9, and the other side of which is provided with a uniform distribution of the refrigerant in the axial direction of the main pipe 11. 13
Is provided via the outflow portion 14. Thus, the vicinity of the end of the enlarged diameter portion 9b of the connection tube 9 is inserted into the widened step portion 11a of the main body tube 11.

Reference numeral 20 denotes an orifice plate for reducing the flow rate of the refrigerant to increase its flow velocity and to change the flow state of the gas-liquid two-phase refrigerant into a spray state. And a locking portion 22 provided on the outflow pipe 13 side.
It consists of Then, the reduced diameter portion 21 is fitted into the inner periphery of the enlarged diameter portion 9b of the connection pipe 9, and the locking portion 22 is locked to the end of the connection pipe 9 so that the reduced diameter portion 21 and the widened step portion 11a of the main pipe 11 can be inserted. It is clamped and fixed.

The orifice plate 20 is attached substantially orthogonally to the axial direction of the connecting pipe 9 and the main pipe 11, that is, the direction of flow of the refrigerant.
An orifice hole 23 concentric with the main tube 11 and having a diameter smaller than the inner diameter of the connection tube 9 is provided. In order to suppress the vibration caused by the pulsation of the refrigerant and to reduce the resonance frequency of the distributor 5, it has a thick structure having a thickness in the flow direction of the refrigerant. It can be lowered. Since the frequency of Karman vortex is proportional to the flow velocity, the amount of circulating refrigerant can also be reduced,
Generation of self-excited sound during normal operation can be suppressed.

Reference numerals 24 and 25 denote first and second tapered portions provided in the orifice holes 23 of the orifice plate 20. The inflow pipe 7 side and the outflow pipe 13 side are each formed into an R shape.
Edges are eliminated near the minimum area 26 near the center of the orifice hole 23 in the thickness direction, so that a smooth flow path is ensured. In this way, the emission of the Karman vortex at the outlet of the orifice plate 20 is suppressed, and there is no point where the resonance frequency of the distributor 5 and the frequency of the Karman vortex coincide with each other. In addition, pressure loss due to rapid contraction and pulsation noise of the refrigerant can be reduced. The orifice plate 20 may have only a taper on the inflow pipe 7 side, or may have only a taper on the outflow pipe 13 side.

Reference numeral 15 denotes a refrigerant collision portion provided on the main body tube 11,
The refrigerant sprayed by the orifice plate 20 is provided near the position facing the orifice hole 23 of the orifice plate 20, and collides with the refrigerant collision portion 15 located downstream thereof.

Thus, the space in the distributor 5 is
Through the orifice plate 20, the first stirring space 16 located on the inflow pipe 7 side having a function of reducing the speed of the refrigerant to reduce the drift is stirred with the refrigerant sprayed by the orifice plate 20. It is divided into a second stirring space 17 located on the outflow pipe 13 side having a function of making the flow uniform.

The refrigerant circulating in the above-mentioned refrigerant circulating device is a hydrochlorofluorocarbon type (R22), a hydrofluorocarbon type (R32, R134A), a mixed refrigerant (R404A, R407C, R407E, R41).
0A), hydrocarbon-based (R290, R600A,
R1270), ammonia-based (R717), etc. are used, but since the respective refrigerant densities are different, the flow rates are different at the same refrigerant circulation amount. Therefore, for the same refrigerant circulation amount, the vortex emission frequency of the Karman vortex street is also different, and the refrigerant circulation amount that matches the resonance frequency of the refrigerant distributor 5 is different. Therefore, by changing the thickness of the orifice plate 20 according to each refrigerant, the point where the resonance frequency of the distributor 5 matches the vortex emission frequency of the Karman vortex street can be shifted, and the hydrodynamic self-excited sound Generation can be suppressed.

In particular, when the hydrofluorocarbon-based refrigerant (R410A) is used, the refrigerant density is higher than that of the hydrochlorofluorocarbon-based refrigerant (R22), so that the flow velocity decreases at the same refrigerant circulation amount. Therefore, the gas-liquid is easily separated and the self-excited sound tends to be generated frequently. Therefore, the above-described means can suppress the generation of the hydrodynamic self-excited sound.

The operation of the first embodiment configured as described above will be described. The refrigerant gas is compressed by the compressor 1 to become high-pressure refrigerant gas, passes through the four-way switching valve 2 and enters the condenser 3, where it is gradually liquefied while being deprived of heat by the cooling fan 3a. Then, all the refrigerant is liquefied. Then, after entering the decompressor 4 and passing therethrough, it becomes a gas-liquid two-phase flow in which the gas phase and the liquid phase are mixed, and passes through the distributor of the distributor 5.

Next, the operation of the refrigerant in the distributor 5 will be described. The gas-liquid two-phase flow that has passed through the pressure reducer 4 connects the pressure reducer 4 in the outdoor unit to the indoor unit in which the distributor 5 exists because the density and the flow rate of the gas phase portion and the liquid phase portion are different. While flowing through the refrigerant extension pipe, the flow is deflected under the influence of the centrifugal force due to the bending of the pipe. If the refrigerant is distributed in the deflected state, the refrigerant flow ratio will be different. Therefore, the refrigerant flows from the inflow pipe 7 of the distributor 5 into the first stirring space 16 to reduce the flow velocity of the refrigerant, and Mitigates the drifted flow.

In this manner, the refrigerant is passed through the first stirring space 16 and then passed through the orifice hole 23 of the orifice plate 20 to be contracted, the flow velocity is increased, and the flow state of the gas-liquid two-phase flow is changed to the spray state. After that, the mixture is made to collide with the refrigerant collision part 15 of the second stirring space part 17, is stirred, mixes the gas and liquid to make a homogeneous flow, and is evenly distributed to the plurality of outlet pipes 13. Thus,
Improves refrigerant distribution performance and suppresses the generation of hydrodynamic self-excited noise.

Embodiment 2 FIGS. 3 (a) and 3 (b) are a side view and a plan view of a main part of embodiment 2 of the present invention. Is provided. Reference numeral 18 denotes a notch provided at the downstream end 8 of the inflow pipe 7. The notch 18 has a depth corresponding to the thickness of the inflow pipe 7, for example, at equal intervals along the circumferential direction of the downstream end 8. Is provided. The notch 18 stirs the refrigerant flowing from the inflow pipe 7 into the first stirring space 16, and suppresses the flow promoting the Karman vortex in the orifice plate 20. Other configurations, operations, and effects are the same as those described in the first embodiment, and a description thereof will not be repeated.

[0023]

As is apparent from the above description, the present invention provides a compressor for compressing a refrigerant gas into a high-pressure refrigerant gas, a condenser for converting a high-pressure refrigerant gas into a liquefied refrigerant, and a gas-liquid two-phase refrigerant. A refrigerant circulating device comprising a pressure reducing device, a refrigerant distributor, etc., which makes a gas-liquid two-phase flow a uniform flow and flows out, wherein an inflow part into which the gas-liquid two-phase flow flows and a downstream side of the inflow part A tapered space portion that widens in the downstream direction, a widened space portion that is located downstream of the tapered space portion and has a refrigerant collision portion, and an orifice hole that has a thickness in the flow direction of the widened space portion and widens. An orifice section that partitions the space section into a first stirring space section including a tapered space section and a second stirring space section including a refrigerant collision section, and an outflow that is located downstream of the widening space section and flows out a homogeneous flow. Section, the resonance frequency of the refrigerant distributor can be reduced. This makes it possible to reduce the vortex shedding frequency of Karman vortex street. Since the frequency of the Karman vortex is proportional to the flow velocity, the amount of circulating refrigerant can also be reduced, and the generation of self-excited noise during normal operation can be suppressed.

Further, since an orifice portion having a taper is provided upstream of the orifice hole, pressure loss can be reduced. Furthermore, since an orifice part with a taper is provided downstream of the orifice hole, Karman vortex is eliminated,
The hydrodynamic self-excited sound can be eliminated. In addition, since the orifice portion having a taper on both the upstream and downstream sides of the orifice hole is provided, pressure loss can be reduced, Karman vortices can be eliminated, and hydrodynamic self-excited sound can be eliminated.

Further, since the orifice portion has an R-shaped taper on both the upstream and downstream sides of the orifice hole and has a smooth structure near the center in the flow direction of the orifice hole, the pressure loss is reduced. , Can eliminate Karman vortex and eliminate hydrodynamic self-excited sound

Further, since a cutout portion having a depth corresponding to the thickness of the inflow portion is provided at the downstream end of the inflow portion, the flow discharged from the inflow pipe is agitated, and the Karman vortex at the orifice portion is promoted. Flow can be suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of Embodiment 1 of the present invention.

FIG. 2 is a longitudinal sectional view of a main part of FIG.

FIG. 3 is a side view and a plan view of a second embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing an example of a conventional refrigerant distributor.

[Explanation of symbols]

1 compressor, 3 condenser, 4 decompressor, 5 distributor, 7
Inflow pipe, 9 connecting pipe, 9a reduced diameter section, 9b expanded diameter section, 9
c Taper section, 11 main pipe, 13 outflow pipe, 15 refrigerant impingement section, 16 first stirring space section, 17 second stirring space section, 18 notch section, 20 orifice plate, 23
Orifice holes, 24 first taper, 25 second taper, 26 minimum area.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Satoshi Suzuki 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation

Claims (6)

[Claims] A compressor for compressing the refrigerant gas into a high-pressure refrigerant gas; a condenser for converting the high-pressure refrigerant gas into a liquefied refrigerant; a decompressor for converting the liquefied refrigerant into a gas-liquid two-phase flow; In a refrigerant circulation device including a refrigerant distributor or the like that makes a flow uniform and flows out, an inflow portion into which the gas-liquid two-phase flow flows, and a tapered space located downstream of the inflow portion and widened in a downstream direction. Part, a widened space portion having a refrigerant collision portion located downstream of the tapered space portion, and a tapered space portion having an orifice hole and having a thickness in the flow direction of the widened space portion. An orifice section partitioned into a first stirring space section including the first stirring space section and a second stirring space section including the refrigerant collision section, and an outflow section located downstream of the widening space section and flowing out a homogeneous flow. A refrigerant distributor characterized by the above-mentioned. 2. The refrigerant distributor according to claim 1, further comprising an orifice portion having a taper upstream of the orifice hole. 3. The refrigerant distributor according to claim 1, further comprising an orifice portion having a taper downstream of the orifice hole. 4. The refrigerant distributor according to claim 1, further comprising an orifice portion having a taper on both the upstream side and the downstream side of the orifice hole. 5. An orifice portion having an R-shaped taper on both the upstream and downstream sides of the orifice hole and having a smooth structure near the center in the flow direction of the orifice hole. Item 7. The refrigerant distributor according to Item 1. 6. The refrigerant distributor according to claim 1, wherein a cutout portion having a depth corresponding to a thickness of the inflow portion is provided at a downstream end of the inflow portion. .