JP4887213B2 - Refrigerant distributor and air conditioner - Google Patents

Description

  The present invention relates to a refrigerant distributor, and is suitable for a refrigerant distributor that distributes refrigerant to a heat exchanger that mainly operates as an evaporator in an air conditioner or the like.

  On the refrigerant inlet side of a heat exchanger that operates as an evaporator used in an air conditioner, a refrigerant distributor for diverting a plurality of refrigerant passages is used.

  A conventional refrigerant distributor is disclosed in Japanese Patent Application Laid-Open No. 2002-22313 (Patent Document 1). This refrigerant distributor is composed of a container having a number of refrigerant pipe connection ports in the longitudinal direction and an inflow pipe inserted from one end of the container to the vicinity of the opposite side, and refrigerant is introduced between the container and the inflow pipe. By flowing, the flow rate of the refrigerant is increased to maintain the mixed state of the gas phase and the liquid phase, and the refrigerant in the lower refrigerant pipe and the upper refrigerant pipe can be evenly divided.

  Another conventional refrigerant distributor is disclosed in Japanese Unexamined Patent Publication No. 2000-356437 (Patent Document 2). This refrigerant distributor has a container-like homogeneous fluidizing section body, one inlet pipe for introducing the refrigerant to the homogeneous fluidizing section body, and branches from the uniform fluidizing section body to supply the refrigerant to two evaporators. Two outlet pipes and a rectifying plate made of a sintered alloy that is disposed in the body of the homogenized fluidizing section and homogenizes the refrigerant component are configured.

JP 2002-22313 A JP 2000-356437 A

  In the refrigerant distributor of Patent Document 1, it causes a significant cost increase due to the inflow pipe inserted from one end of the container to the vicinity of the opposite side, and it is extremely difficult to evenly distribute the refrigerant only by increasing the flow rate of the refrigerant. There is a problem. In particular, in a capacity-controlled air conditioner that operates by controlling the amount of refrigerant circulation, which has been widely used recently, the flow rate of the refrigerant becomes slow depending on the operating state, and the gas-liquid two-phase flow is reduced by gravity. Under the influence, there is a problem that liquid refrigerant increases in the lower distribution pipe.

  Further, in the refrigerant distributor of Patent Document 2, two outlet pipes for supplying refrigerant to the two evaporators are directly branched from the homogenized fluidizing section body, so that the heat exchanger tube of the heat exchanger is connected from the homogeneous fluidizing section body. As the distance to the part becomes longer, the outlet pipe needs to be bent and the processing becomes complicated, resulting in an increase in cost and a larger installation space for the current divider compared to the current divider of Patent Document 1. Therefore, there is a problem that the device cannot be made compact.

  An object of the present invention is to provide a refrigerant distributor capable of improving the uniformity of refrigerant distribution while maintaining low cost and space saving.

A first aspect of the present invention is a refrigerant distributor having a plurality of heat transfer tubes for flowing refrigerant in parallel and connected to a heat exchanger operating as an evaporator, and distributing and flowing the refrigerant to the plurality of heat transfer tubes. A header extending long opposite to the inlet side of the plurality of heat transfer tubes, a branch tube extending from the header and extending in a straight line and connected to the inlet side of the plurality of heat transfer tubes, and an inlet of the header A homogenized fluidizing section body connected to the side and having a channel cross-sectional area larger than that of the header, a porous body disposed in an intermediate portion of the homogeneous fluidizing section body and having fine pores, An inlet-side mesh filter having a flow area larger than the inlet area of the porous body on the inlet side of the body and having a mesh diameter smaller than the average pore diameter of the porous body, and an outlet area of the porous body on the outlet side of the porous body Larger distribution area Wherein in that a homogeneous Ryuka portion consisting outlet mesh filter having a small mesh size than the average pore diameter of the porous body while.

According to a second aspect of the present invention, a compressor that compresses the refrigerant, a condenser that condenses the refrigerant compressed by the compressor, a decompression unit that decompresses the refrigerant condensed by the condenser, and the refrigerant are arranged in parallel. An evaporator that has a large number of heat transfer tubes that flow through the evaporator and that evaporates the refrigerant depressurized by the decompression means; a refrigerant distributor that is connected to the evaporator and distributes and flows the refrigerant to the plurality of heat transfer tubes; and the evaporation An air conditioner having a blowing means for blowing air to the heat exchanger, wherein the refrigerant distributor includes a header extending long facing the inlet side of the plurality of heat transfer tubes, and a plurality of straight lines branched from the header. A branch pipe that extends in a shape and is connected to the inlet side of the plurality of heat transfer tubes, and a homogenized fluidized section body that is connected to the inlet side of the header and has a channel cross-sectional area larger than the channel cross-sectional area of the header; Located in the middle of the body of this homogeneous fluidization section and A porous body having fine pores, an inlet-side mesh filter having a flow area larger than the inlet area of the porous body on the inlet side of the porous body and a mesh diameter smaller than the average pore diameter of the porous body, and the porous body And a homogeneous fluidizing portion comprising an outlet-side mesh filter having a flow area larger than the outlet area of the porous body and a mesh diameter smaller than the average pore diameter of the porous body.
More preferred specific configuration examples in the first and second aspects of the present invention are as follows.
(1) The inlet-side mesh filter is formed to protrude in a conical shape on the inlet side, and the outlet-side mesh filter is formed to protrude in a conical shape on the outlet side.

  Further, according to a third aspect of the present invention, there is provided a refrigerant distribution that has a large number of heat transfer tubes that flow refrigerant in parallel and is connected to a heat exchanger that operates as an evaporator, and distributes and flows the refrigerant to the plurality of heat transfer tubes. A plurality of headers extending long opposite to the inlet sides of the plurality of heat transfer tubes, a plurality of branches extending from the header, extending in a straight line, and connected to the inlet sides of the plurality of heat transfer tubes and to the heat exchanger A branch pipe having a difference in inner diameter according to the wind speed distribution of the air to be ventilated, and a homogenized fluidized body body connected to the inlet side of the header and having a flow path cross-sectional area larger than the flow path cross-sectional area of the header And a homogeneous fluidizing part which is arranged in the middle part of the homogeneous fluidizing part body and is made of a porous body having fine pores.

  According to the refrigerant distributor of the present invention, it is possible to improve the uniform refrigerant distribution while maintaining low cost and space saving.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. The same reference numerals in the drawings of the respective embodiments indicate the same or equivalent.
(First embodiment)
A refrigerant distributor according to a first embodiment of the present invention will be described with reference to FIGS.

  An outline of a refrigeration cycle using the refrigerant distributor 40 of the present embodiment will be described with reference to FIG. In FIG. 1, the solid line arrows indicate the refrigerant flow during the heating operation, and the broken line arrows indicate the refrigerant flow during the cooling operation.

  The refrigeration cycle at the time of heating operation will be described. The gas refrigerant that has been compressed by the compressor 1 and becomes high temperature and pressure passes through the four-way valve 2, passes through the gas blocking valve 10 and the gas connection pipe 9, and goes to the indoor unit 200. It is guided. The refrigerant guided to the indoor unit 200 is cooled and condensed by the air sent by the indoor blower 31 in the indoor heat exchanger 8, and becomes a liquid refrigerant. The indoor heat exchanger 8 acts as a condenser during heating operation. This liquid refrigerant passes through the open indoor expansion valve 7, passes through the liquid connection pipe 6 and the liquid blocking valve 5, and is returned to the outdoor unit 100.

  The liquid refrigerant returned to the outdoor unit 100 is depressurized and boiled by the outdoor expansion valve 4 and enters a gas-liquid two-phase state. The gas-liquid two-phase refrigerant is branched in the middle while the two-phase flow gas phase and liquid phase are refined and homogenized by the homogeneous flow unit 50 and sent upward by the liquid header 57. A liquid branch pipe 58 (see FIG. 2) branches into a plurality of flow paths. The refrigerant branched into each liquid branch pipe 58 flows into each heat transfer pipe 31 (see FIG. 2) of the outdoor heat exchanger 3, is heated by the outdoor air sent by the outdoor blower 30, and evaporates to become a gas refrigerant. Become. The outdoor heat exchanger 3 acts as an evaporator during heating operation. The gas refrigerant passes through the four-way valve 2 and returns to the compressor 1 through the accumulator 11 again. This forms a series of cycles in which the refrigerant circulates.

  Here, fluorocarbon refrigerants such as R410A, R404A, R407C, and R134a are generally used as refrigerants in the refrigeration cycle. Etc. may be used.

  And the flow direction of a refrigerant | coolant can be switched by switching the four-way valve 2 like the continuous line of FIG. 1, and it can also be set as the cooling operation. In this case, the outdoor heat exchanger 3 functions as a condenser and the indoor heat exchanger 8 functions as an evaporator.

  Next, the configuration and operation of the outdoor heat exchanger 3, the outdoor refrigerant distributor 40, and the outdoor expansion valve 4 during the heating operation that acts as an evaporator will be described with reference to FIGS.

  As shown in FIG. 2, the outdoor heat exchanger 3 is configured by a so-called fin tube type heat exchanger composed of a large number of heat transfer tubes 31 and fins 32 that flow refrigerant in parallel. The heat transfer tube 31 is formed of a U-shaped tube, and the inlet side and the outlet side of each heat transfer tube 31 are positioned on one surface and are arranged vertically.

  The outdoor refrigerant distributor 40 is for distributing and flowing the refrigerant to a large number of heat transfer tubes 31 of the outdoor heat exchanger 3, and as shown in FIG. 2, a liquid header 57, a liquid branch pipe 58, a homogeneous flow Part 50, gas header 70 and gas branch pipe 71.

  The liquid header 57 is disposed so as to extend vertically up and down facing the inlet side of the large number of heat transfer tubes 31. The flow path cross-sectional area of the liquid header 57 is set larger than the flow path cross-sectional areas of the outdoor heat exchanger 3 and the liquid branch pipe 58. A number of liquid branch pipes 58 are branched from the liquid header 57 and extend in a straight line, and their tip ends are connected to the inlet side of each heat transfer pipe 31.

  As shown in FIGS. 2 and 3, the homogeneous fluidizing section 50 is connected to the inlet side of the liquid header 57 and has a uniform fluidizing section body 51 having a channel cross-sectional area larger than that of the liquid header 57. The porous body 53 is arranged in an intermediate portion in the uniform fluidizing section body 51 and has fine holes. The porous body 53 is fixed by caulking portions 55a and 55b so that there is no gap between the porous body 53 and the uniform fluidizing portion body 51. For this reason, all the gas-liquid two-phase refrigerant flowing from the inlet 52 passes through the porous body 53 and flows out from the outlet 54 to the liquid header 57. Here, the porous body 53 is composed of a nickel metal sintered body or a compression member made of a demister material, and is formed to have pores and gap sizes of about 1 to 0.3 mm.

  The gas header 70 is disposed so as to extend vertically up and down facing the outlet sides of the numerous heat transfer tubes 31. The flow path cross-sectional area of the gas header 70 is set larger than the flow path cross-sectional areas of the outdoor heat exchanger 3 and the liquid branch pipe 58. A large number of gas branch pipes 71 are branched from the gas header 70 and extend in a straight line, and the tip ends thereof are connected to the outlet sides of the heat transfer pipes 31. The liquid header 57 and the gas header 70 are disposed adjacent to each other on the left and right.

  The liquid refrigerant that has flowed into the outdoor unit 100 during the heating operation is reduced in pressure and boiled when passing through the outdoor expansion valve 4 to be in a gas-liquid two-phase state. The gas-liquid two-phase refrigerant is branched in the middle while the two-phase gas phase and liquid phase are refined and homogenized by the homogenization unit 50 and then sent upward through the liquid header 57. The liquid branch pipe 58 branches into a plurality of flow paths. Since the gas-liquid two-phase flow is kept fine at the inlet of the liquid branch pipe 58, the dryness (the mass flow ratio between the liquid phase and the gas phase) of any of the liquid branch pipes 58 from the lower part to the upper part. Are equal. Therefore, in the case where the outdoor air passing through the outdoor heat exchanger 3 has a uniform wind speed distribution, if the refrigerant flow rate and dryness are equally distributed, the refrigerant state in the gas branch pipe 71 at the outlet of the heat exchanger is Even in the road, the refrigerant state has substantially the same specific enthalpy, and as a result, the heat exchange amount of the heat exchanger can be maximized.

  In the case where the outdoor air passing through the outdoor heat exchanger 3 has a non-uniform wind speed distribution, a difference is made in the inner diameter of the liquid branch pipe 58 according to the distribution, or the outdoor heat exchanger for each flow path. The refrigerant distribution can be easily adjusted by making a difference in the length of the three heat transfer tubes 31.

  Next, the difference in the flow pattern in the liquid header 57 depending on the presence / absence of the uniform fluidizing section 50 will be described with reference to FIGS. 4 and 5 show the case where the homogeneous fluidizing section 50 is not provided, and FIGS. 6 and 7 show the case where the present embodiment has the homogeneous fluidizing section 50.

  FIG. 4 schematically shows a flow pattern in the liquid header 57 and the liquid branch pipes 58a to 58f when the homogeneous fluidizing part 50 is not provided, and FIG. 5 shows each liquid branch when the homogeneous fluidizing part 50 is not provided. The dryness and flow rate of the tubes 58a-58f are shown.

The refrigerant that has been depressurized and boiled by the outdoor expansion valve 4 to form a two-phase flow rises in the liquid header 57 as shown in FIG. The flow mode here is an annular flow, a churn flow, or a slag flow depending on the mass flux (unit: kg / ms ² ) of the liquid and the gas. The faster the refrigerant flow rate, the easier it is to form an annular flow, and the slower the flow rate, the more likely it is a churn flow or slag flow that is an intermittent flow.

  For this reason, in the liquid branch pipe 58a located in the lowest part of the liquid header 57, the ratio of a liquid refrigerant increases, and in the liquid branch pipe 58f located in an upper part, the ratio of a gas refrigerant increases. That is, as shown in FIG. 5, the flow rate of the liquid branch pipe 58a located in the lower part is high and the dryness is high, and the liquid branch pipe located in the upper part has a low flow rate and the dryness is high. Therefore, in the refrigerant distributor in the case of not having the homogenization flow part 50, the dryness distribution to the liquid branch pipes 58a to 58f cannot be made uniform.

  FIG. 6 schematically shows a flow pattern in the liquid header 57 and the liquid branch pipes 58a to 58f in the case of having the homogeneous fluidizing part 50 of the present embodiment, and FIG. 7 is a case of having the homogeneous fluidizing part 50 in the present embodiment. The dryness and flow rate of each of the liquid branch pipes 58a to 58f are shown.

  The refrigerant that has been reduced in pressure and boiled by the outdoor expansion valve 4 to become a two-phase flow becomes a homogeneous flow in which the gas-liquid two-phase flow bubbles and liquid are mixed by the homogeneous flow unit 50, as shown in FIG. It flows into the liquid header 57 and rises in the liquid header 57. In particular, since the homogenized fluidized body body 51 has a channel cross-sectional area larger than the channel cross-sectional area of the liquid header 57, the flow rate of the refrigerant is slowed to ensure that the gas-liquid two-phase flow bubbles and liquid are mixed. In addition, the flow rate of the refrigerant in the liquid header 57 is increased to maintain the mixed state.

  For this reason, in the liquid branch pipe 58a located at the lower part and the liquid branch pipe 58f located at the upper part, a homogeneous gas-liquid mixed refrigerant is distributed. That is, as shown in FIG. 7, it can be seen that the flow rate and the dryness are almost constant regardless of the position of the distribution pipe. In a capacity-controlled air conditioner that operates by controlling the refrigerant circulation rate, the flow rate and dryness can be made constant regardless of the position of the distribution pipe even when the flow rate of the refrigerant is low.

  In this way, according to the refrigerant distributor 40 of the present embodiment, it is possible to improve the uniformity of the refrigerant distribution while maintaining low cost and space saving. Compared to conventional refrigerant distributors, where refrigerant distribution deteriorates or the cost of the refrigerant distributor rises significantly due to an increase in the diversion of the heat exchanger, this embodiment is a low-cost refrigerant with good distribution performance. It is possible to provide a distributor.

In addition, since the configuration and operation of the indoor heat exchanger 8, the indoor refrigerant distributor 60, and the indoor expansion valve 8 during the cooling operation that acts as an evaporator are basically the same as the configuration and operation of the corresponding devices on the outdoor side, A duplicate description is omitted.
(Second to fourth embodiments)
Next, 2nd-4th embodiment of this invention is described using FIGS. 8-10. The second to fourth embodiments differ from the first embodiment in the following points, and are basically the same as the first embodiment in other points.

  In the second embodiment, as shown in FIG. 8, mesh filters 56 a and 56 b are installed upstream and downstream of the porous body 53. Specifically, the inlet-side mesh filter 56 a having a flow area larger than the inlet area of the porous body 53 on the inlet side of the porous body 53 and having a mesh diameter smaller than the average pore diameter of the porous body 53, and the outlet of the porous body 53 An outlet-side mesh filter 56b having a flow area larger than the outlet area of the porous body 53 and having a mesh diameter smaller than the average pore diameter of the porous body 53 is installed on the side. The inlet side mesh filter 56a is formed so as to project conically on the inlet side, and the outlet side mesh filter 56b is formed so as to project conically on the outlet side. As the mesh filters 56a and 56b, those having a mesh diameter finer than the average pore diameter of 1 to 0.3 mm of the porous body 53 are used, for example, those having a mesh of 100 mesh (0.254 mm pitch).

  In the case where the mesh filters 56a and 56b are provided in this manner, it is possible to prevent contamination such as metal powder in the refrigeration cycle from clogging the gap between the porous bodies.

  In the third embodiment, as shown in FIG. 9, the refrigerant distributor 50 is used in a structure that allows a gas-liquid two-phase flow to flow from the upper part of the liquid header 57. Also in this case, as in the case of the flow from the lower part as in the first embodiment, the refrigerant dryness and flow rate are almost equally distributed regardless of whether the liquid branch pipe 58 is at the upper part or the lower part. It is possible.

  In the fourth embodiment, as shown in FIG. 10, the refrigerant distributor 50 is used in a structure that allows a gas-liquid two-phase flow to flow from the center of the liquid header 57. In this case as well, as in the case of the flow from the lower part or the upper part as in the first and second embodiments, the dryness and the flow rate of the refrigerant are almost equally distributed regardless of the vertical position of the liquid branch pipe 58. It is possible.

It is a block diagram of the refrigerating cycle of the air conditioner provided with the refrigerant distributor of 1st Embodiment of this invention. It is explanatory drawing which shows the outdoor heat exchanger at the time of heating operation of the air conditioner of FIG. 1, an outdoor refrigerant | coolant divider | distributor, and an outdoor expansion valve. It is sectional drawing of the homogeneous flow part in the refrigerant | coolant divider | distributor of FIG. It is a figure explaining the internal flow state of the refrigerant distributor which does not have a homogeneous flow part. It is a characteristic view of the refrigerant distributor which does not have a homogeneous flow part. It is a figure explaining the internal flow state of the refrigerant distributor which has a homogeneous flow part of FIG. It is a characteristic view of the refrigerant distributor which has the homogeneous flow part of FIG. It is sectional drawing of the homogeneous flow part in the refrigerant distributor of 2nd Embodiment of this invention. It is explanatory drawing which shows the outdoor heat exchanger, the outdoor refrigerant distributor, and the outdoor expansion valve at the time of the heating operation of the air conditioner of 3rd Embodiment of this invention. It is explanatory drawing which shows the outdoor heat exchanger, the outdoor refrigerant distributor, and the outdoor expansion valve at the time of the heating operation of the air conditioner of 4th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Four-way valve, 3 ... Outdoor heat exchanger, 4 ... Outdoor expansion valve, 5 ... Liquid blocking valve, 6 ... Liquid side connection piping, 7 ... Indoor expansion valve, 8 ... Indoor heat exchanger, 9 DESCRIPTION OF SYMBOLS ... Gas side connection piping, 10 ... Gas blocking valve, 11 ... Accumulator, 31 ... Heat transfer pipe, 32 ... Fin, 40 ... Outdoor refrigerant distributor, 50 ... Homogeneous fluidization part, 51 ... Homogeneous fluidization part fuselage, 52 ... Flow Inlet, 53 ... porous body, 54 ... outlet, 55a, 55b ... caulking, 56a, 56b ... filter, 57 ... liquid header, 58a-58f ... liquid branch pipe, 60 ... indoor refrigerant distributor, 70 ... gas header, 71 ... Gas distribution pipe, 100: outdoor unit, 200: indoor unit.

Claims (4)

In a refrigerant distributor having a large number of heat transfer tubes that flow the refrigerant in parallel and connected to a heat exchanger that operates as an evaporator, and distributing and flowing the refrigerant to the multiple heat transfer tubes,
A header extending long facing the inlet side of the plurality of heat transfer tubes;
A branch pipe branched from the header and extending in a straight line and connected to the inlet side of the heat transfer pipe;
Having an inlet connected to the side and homogeneous Ryuka unit body having a flow path cross-sectional area larger than flow path cross-sectional area of the header is disposed in an intermediate portion of the homogeneous Ryuka section fuselage this and fine holes of the header A porous body , an inlet-side mesh filter having a flow area larger than an inlet area of the porous body on the inlet side of the porous body and having a mesh diameter smaller than an average pore diameter of the porous body, and the outlet side of the porous body A refrigerant distributor, comprising: a homogeneous fluidizing portion having an outlet mesh filter having a flow area larger than an outlet area of the porous body and having a mesh diameter smaller than an average pore diameter of the porous body . 2. The refrigerant distributor according to claim 1, wherein the inlet-side mesh filter is formed to project conically on the inlet side, and the outlet-side mesh filter is formed to project conically on the outlet side . . A compressor for compressing the refrigerant;
A condenser for condensing the refrigerant compressed by the compressor;
Decompression means for decompressing the refrigerant condensed by the condenser;
An evaporator having a plurality of heat transfer tubes for flowing the refrigerant in parallel and evaporating the refrigerant decompressed by the decompression means;
A refrigerant distributor connected to the evaporator and distributing and flowing the refrigerant to the plurality of heat transfer tubes;
In an air conditioner provided with a blowing means for blowing air to the evaporator,
The refrigerant distributor is
A header extending long facing the inlet side of the plurality of heat transfer tubes;
A branch pipe branched from the header and extending in a straight line and connected to the inlet side of the heat transfer pipe;
Homogeneous fluidized section body connected to the inlet side of the header and having a flow path cross-sectional area larger than the flow path sectional area of the header, and a porous body disposed in an intermediate portion of the homogeneous fluidized section body and having fine holes Body, an inlet-side mesh filter having a flow area larger than the inlet area of the porous body on the inlet side of the porous body and having a mesh diameter smaller than the average pore diameter of the porous body, and the porous on the outlet side of the porous body A homogeneous fluidizing portion comprising an outlet-side mesh filter having a flow area larger than the outlet area of the body and having a mesh diameter smaller than the average pore diameter of the porous body.
An air conditioner characterized by that. 4. The air conditioner according to claim 3, wherein the inlet-side mesh filter is formed so as to project conically on the inlet side, and the outlet-side mesh filter is formed so as to project conically on the outlet side. .

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