JP2008039304A - Heat exchanger - Google Patents

Abstract

A heat exchanger for improving heat exchange efficiency by distributing gas-liquid two-phase refrigerant flowing through a refrigerant inlet header pipe evenly.
A refrigerant inflow side header pipe 1 and a refrigerant outflow side header pipe 2 which are arranged with the pipe axis direction being horizontal, are arranged in parallel in the vertical direction between the two header pipes, and both end portions thereof are A plurality of heat transfer pipes 3 inserted and connected in a line in the tube axis direction of both header pipes and through which the refrigerant passes, and the gas refrigerant and liquid refrigerant flowing into the refrigerant inflow portion 5 of the refrigerant inflow side header pipe 1 Since the gas-liquid diffuser 8 for mixing and diffusing is disposed, the gas refrigerant and the liquid refrigerant are well mixed by the gas-liquid diffuser 8 and the gas refrigerant and the liquid refrigerant until reaching the plurality of heat transfer tubes are substantially mixed. It can distribute equally and can improve heat exchange efficiency.
[Selection] Figure 2

Description

  The present invention relates to a heat exchanger provided with a plurality of heat transfer tubes that circulate refrigerant in parallel between a refrigerant inflow side header tube and a refrigerant outflow side header tube.

  Conventionally, as a heat exchanger (evaporator) constituting a refrigeration cycle of an air conditioner or the like, a cylindrical refrigerant inflow side header pipe and a refrigerant outflow side header pipe are arranged vertically with the pipe axis direction horizontal, A plurality of heat transfer tubes through which the refrigerant passes vertically are arranged in parallel between the refrigerant inflow side header tube and the refrigerant outflow side header tube, and both ends thereof are inserted and connected in a row in the tube axis direction of the header tube. A heat transfer tube is known in which the inside is finely divided and a plurality of refrigerant flow paths are formed (see Patent Document 1).

  In the heat exchanger of Patent Document 1, the gas-liquid two-phase refrigerant flows into the header pipe from the refrigerant inflow pipe formed at the end of the refrigerant inflow side header pipe, and is divided and transmitted in the refrigerant inflow side header pipe. The refrigerant passes through the heat pipe, the liquid refrigerant evaporates in the heat transfer pipe and flows into the refrigerant outflow side header pipe while the gas and liquid are separated, and the refrigerant divided in the refrigerant outflow side header pipe joins to form the refrigerant in the refrigerant outflow side header pipe The refrigerant flows out from the outflow pipe.

Moreover, in the heat exchanger of patent document 1, by providing an inclination part in the edge part of a heat exchanger tube, contact with a heat exchanger tube and a liquid refrigerant is ensured among the circulating gas-liquid refrigerant, and insertion of a heat exchanger tube is carried out. The liquid refrigerant can be evenly divided without adverse effects due to errors, and the liquid refrigerant is efficiently evaporated to improve the heat exchange efficiency.
Japanese Patent No. 3133897

  By the way, as shown in Patent Document 1, the refrigerant flowing from the refrigerant inflow pipe into the refrigerant inflow side header pipe is in a gas-liquid two-phase state, and this gas-liquid two-phase refrigerant is the refrigerant flowing in the refrigerant inflow side header pipe. The refrigerant gasifies toward the downstream side in the flow direction. Therefore, only the gasified refrigerant exists in the heat transfer tube near the downstream end, and if only the gas refrigerant flows through the heat transfer tube, the heat exchange efficiency in the heat transfer tube is deteriorated.

  In particular, when a flat heat transfer tube with a plurality of refrigerant flow paths divided into the inside is used as the heat transfer tube, the header tube inserted and connected to the width of the heat transfer tube inevitably has a pipe diameter. Big ones must be used. For this reason, the inner diameter of the refrigerant inflow side header pipe is increased, and the refrigerant flowing through the refrigerant is easily separated into two phases, and the above-described problem is more likely to occur.

  In view of the above-described problems, an object of the present invention is to provide a heat exchanger that can evenly distribute the gas-liquid two-phase refrigerant flowing through the refrigerant inflow side header pipe and improve the heat exchange efficiency.

  In order to achieve the above object, according to the present invention, the gas refrigerant and the liquid refrigerant flowing into the refrigerant inflow portion of the refrigerant inflow side header pipe are uniformly mixed and diffused to flow, and the axial direction of the refrigerant inflow side header pipe A uniform gas-liquid mixed refrigerant is formed and brought into contact with the heat transfer tube.

  That is, in the present invention, the refrigerant inflow side header pipe and the refrigerant outflow side header pipe arranged with the pipe axis direction being horizontal, the two header pipes are arranged in parallel in the vertical direction, and both ends are the above-mentioned A heat exchanger having a plurality of heat transfer tubes inserted and connected in a line in the tube axis direction of both header tubes and through which the refrigerant passes, wherein the gas refrigerant flows into the refrigerant inflow portion of the refrigerant inflow header tube A gas-liquid diffuser that mixes and diffuses the liquid refrigerant and the liquid refrigerant is arranged.

  According to the above configuration, the refrigerant flowing into the refrigerant inflow portion of the refrigerant inflow side header pipe is easily separated into gas refrigerant and liquid refrigerant due to its specific gravity, but both refrigerants are mixed when passing through the gas-liquid diffuser. Because it is diffused, the gas refrigerant and liquid refrigerant are mixed well, and the gas refrigerant and liquid refrigerant are distributed almost evenly until they reach the plurality of heat transfer tubes arranged in the pipe axis direction of the refrigerant inflow header pipe And heat exchange efficiency can be improved.

  Here, the gas-liquid diffuser is formed with a large number of flow holes composed of small holes enough to mix the gas refrigerant and the liquid refrigerant, and the gas-liquid refrigerant is mixed by passing through the flow holes. Can do. As one means for forming the large number of flow holes, the wire is bent and formed into a cylindrical shape having a width in the tube axis direction of the refrigerant inflow portion. Then, the bent wire forms a plurality of flow holes that are bent in a wave shape between the wires and intersect each other, and the gas-liquid refrigerant passing therethrough is mixed and diffused.

  In addition, since the gas-liquid diffuser is formed in a columnar shape, the gas-liquid diffuser can be fitted and brought into close contact with the pipe of the refrigerant inflow side header pipe, and all of the refrigerant passing through the refrigerant inflow part can be mixed and diffused.

  The material of the wire is not particularly limited, and for example, a wire-like metal wire such as stainless steel that can be easily obtained can be used.

  Further, in order to distribute the gas-liquid mixed refrigerant substantially evenly in the direction of the pipe axis of the refrigerant inflow side header pipe, a refrigerant inflow part is formed at both ends of the refrigerant inflow side header pipe, and the gas liquid is formed in each refrigerant inflow part on both sides. A diffuser can be arranged to cause gas-liquid mixing and diffusion. Thereby, the gas-liquid mixed refrigerant can be more evenly distributed, and the heat exchange efficiency can be improved.

  As described above, according to the present invention, the refrigerant flowing into the refrigerant inflow portion of the refrigerant inflow side header pipe is mixed and diffused when passing through the gas-liquid diffuser, so that the gas refrigerant and the liquid refrigerant are well mixed, The gas refrigerant and the liquid refrigerant can be distributed substantially evenly until they reach the plurality of heat transfer tubes arranged in the tube axis direction of the refrigerant inflow header tube, and the heat exchange efficiency can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a heat exchanger showing a first embodiment of the present invention, FIG. 2 is a cross-sectional view of the main part of the refrigerant inflow header pipe of FIG. 1, and FIG. 3 is an exploded perspective view showing the refrigerant inflow part. is there.

  The heat exchanger of the present embodiment is used as a heat exchanger constituting a refrigeration cycle such as an air conditioner, for example, an evaporator, and is formed of a cylindrical hollow body with the tube axis direction horizontal. The refrigerant inflow side header pipe 1 and the refrigerant outflow side header pipe 2 are disposed, and a plurality of flat plates through which the refrigerant passes vertically between the refrigerant inflow side header pipe 1 and the refrigerant outflow side header pipe 2. The heat transfer tubes 3 are arranged in parallel, and both end portions thereof are inserted and connected in a line in the tube axis direction of the header tubes 1 and 2.

  The refrigerant inflow side header pipe 1 is made of a cylindrical aluminum pipe, and is formed by forming a plate-like member into a tubular shape by roll forming and seam welding. The pipe end of the header pipe 1 is closed, and the refrigerant inflow pipe 4 is connected to one end of the pipe by brazing or screw fitting. The inner diameter of the refrigerant inflow header pipe 1 is set to a size that allows the refrigerant to flow between the header pipe 1 and the internal flow passage 6 of the heat transfer pipe 3 by inserting the end of the flat heat transfer pipe 3.

  Therefore, in the header pipe 1 on the refrigerant inflow side, the gas-liquid two-phase refrigerant flowing from the refrigerant inflow pipe 4 is easily separated into the gas refrigerant and the liquid refrigerant on the downstream side in the refrigerant flow direction. A gas-liquid diffuser 8 is provided for mixing and diffusing the gas refrigerant and the liquid refrigerant flowing into the refrigerant inflow portion 5 of the refrigerant inflow side header pipe 1 in a mixed manner.

  The gas-liquid diffuser 8 is composed of small holes that allow mixing and diffusion of gas refrigerant and liquid refrigerant. For example, the gas-liquid diffuser 8 is formed in a cylindrical shape having a wire-like stainless wire bent and having a width in the tube axis direction of the refrigerant inflow portion 5. Due to the bending of the wire, a large number of flow holes 9 that are bent in a wave shape and intersect each other are formed, and the gas-liquid refrigerant flows through the flow holes 9 so that the gas refrigerant and the liquid refrigerant are mixed and diffused.

  In addition, the wire in which the gas-liquid diffuser 8 is formed is not limited to a stainless steel wire, but may be another metal wire such as copper. Furthermore, not only a metal wire but a thermosetting synthetic resin wire may be used, and the material is not particularly limited. Further, the gas-liquid diffuser 8 is not limited to an embodiment formed by bending a wire, and may be a porous body made of an open-cell foam.

  These gas-liquid diffusers 8 are accommodated in the refrigerant inflow portion 5 at the end of the refrigerant inflow side header tube 1. The gas-liquid diffuser 8 is formed in accordance with the inner diameter of the cylindrical refrigerant inflow portion 5. The width (the length in the tube axis direction) of the gas-liquid diffuser 8 is formed to a length that allows the gas refrigerant and the liquid refrigerant to be mixed and diffused.

  The gas-liquid diffuser 8 is fitted into the refrigerant inflow part before attaching the refrigerant inflow pipe 4 to the header pipe 1 and then completed by retrofitting the refrigerant inflow pipe 4 by brazing or the like. In order to make the structure detachable, the lid member 11 with the refrigerant inflow pipe 4 may be screwed to the pipe end of the header pipe 1.

  As shown in FIG. 3, the heat transfer tube 3 is a tubular and flat aluminum tube having a plurality of flow paths formed in parallel therein, and is formed by extrusion molding. The thickness is set to about 1 mm, and the width is set to about 10 mm to 20 mm. The heat transfer tubes 3 are arranged in parallel along the tube direction of the header tubes 1 and 2 with an interval substantially equal to the thickness thereof.

  A refrigerant inflow header pipe 1 is placed below and horizontally below the heat transfer pipe 3, and a refrigerant outflow side header pipe 2 is arranged above the heat transfer pipe 3. Are circulated from the refrigerant inflow side header pipe 1 through the heat transfer pipe 3 from the lower side to the upper side, merged in the refrigerant outflow side header pipe 2 and discharged from the refrigerant outflow pipe 7 at the end thereof. In the meantime, heat is exchanged with the outside air in the heat transfer tube 3, and the outside air is cooled and sent out as cold air.

  The refrigerant outflow side header pipe 2 is made of a cylindrical aluminum pipe, and a plate-like member is formed into a tubular shape by roll forming and seam-welded. One side of the refrigerant outflow side header pipe 2 is closed, and the refrigerant outflow pipe 7 is joined to the other end of the pipe by brazing or the like. The inner diameter of the refrigerant outflow side header pipe 2 is set to a size that allows the refrigerant to merge with the internal flow passage 6 of the heat transfer pipe 3 by inserting the end of the flat heat transfer pipe 3.

  The refrigerant inflow side header pipe 1, the refrigerant outflow side header pipe 2 and the heat transfer pipe 3 are all made of aluminum, thereby reducing the weight and reducing the production cost.

  In addition, in the illustrated heat exchanger, a large number of heat transfer tubes 3 are arranged to increase the refrigerant flow rate and to improve the heat exchange efficiency. A structure in which fins (not shown) for efficiently performing the above operation are fixed may be employed.

  In the heat exchanger having the above configuration, when the gas-liquid two-phase refrigerant flows into the refrigerant inflow side header pipe 1 from the refrigerant inflow pipe 4, when passing through the gas-liquid diffuser 8, it passes through the numerous flow holes 9. It is gas-liquid mixed here. The gas-liquid mixed refrigerant comes into contact with the end portions of the heat transfer tubes 3 arranged in the tube axis direction, rises in the heat transfer tubes 3 through the internal flow passages 6 of the heat transfer tubes 3, and flows out of the refrigerant outflow side header tubes 2. Are merged and discharged from the refrigerant outflow pipe 7. During this time, mainly the liquid refrigerant exchanges heat with the outside air in the heat transfer pipe section, cools the outside air and sends it out as cold air, while the refrigerant itself is heat exchanged and gasified and sent to the refrigerant outflow side header pipe 2.

  At this time, the refrigerant flowing into the refrigerant inflow portion 5 of the refrigerant inflow side header pipe 1 is easily separated into the upper gas refrigerant and the lower liquid refrigerant because of the specific gravity. Are mixed and diffused by a large number of flow holes 9 that are wavy and intersect with each other, so that the gas refrigerant and the liquid refrigerant are mixed well and are arranged in the pipe axis direction of the refrigerant inflow header pipe 1. The gas refrigerant and liquid refrigerant until reaching the heat transfer tube 3 can be distributed almost evenly, and the heat exchange efficiency can be improved.

  FIG. 4 is a cross-sectional view of the refrigerant inflow side header pipe of the heat exchanger according to the second embodiment of the present invention. As shown in the figure, in the present embodiment, refrigerant inflow portions 5 and 5a are formed at both ends of the refrigerant inflow side header tube 1, refrigerant inflow tubes 4 and 4a are connected to the respective refrigerant inflow portions, and a gas-liquid diffuser. 8 is arranged to allow gas-liquid refrigerant to be mixed and diffused.

  In the above configuration, the refrigerant inflow portions 5 and 5a are formed at both ends of the refrigerant inflow side header tube 1, the refrigerant inflow tubes 4 and 4a are connected to the respective refrigerant inflow portions, and the gas-liquid diffuser 8 is disposed. The gas-liquid refrigerant flowing in from both sides of the header pipe 1 is mixed and diffused by the gas-liquid diffuser 8 on both sides and distributed to the heat transfer pipe 3. Therefore, the gas-liquid mixed refrigerant can be more evenly distributed than in the first embodiment, and the heat exchange efficiency can be improved. Since other configurations and operations are the same as those of the first embodiment, description thereof will be omitted.

  Note that the present invention is not limited to the above-described embodiment, and it is needless to say that many modifications and changes can be made within the scope of the present invention. For example, in the above embodiment, the header pipe is made of aluminum, but it is needless to say that the header pipe may be made of another material having good thermal conductivity such as copper.

The front view of the heat exchanger which shows the 1st Embodiment of this invention Cross-sectional view of the main part of the header pipe on the refrigerant inflow side Exploded perspective view showing refrigerant inlet Sectional drawing of the refrigerant | coolant inflow side header pipe | tube of the heat exchanger which is 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Refrigerant inflow side header pipe 2 Refrigerant outflow side header pipe 3 Heat transfer pipe 4 Refrigerant inflow pipe 5 Refrigerant inflow part 6 Internal flow path 7 Refrigerant outflow pipe 8 Gas-liquid diffuser 9 Flow hole 11 Lid

Claims (6)

  A refrigerant inflow side header pipe and a refrigerant outflow side header pipe arranged with the pipe axis direction horizontal, and are arranged in parallel in the vertical direction between the two header pipes, and both ends are pipe axes of the two header pipes A heat exchanger having a plurality of heat transfer tubes inserted and connected in a row in a direction and through which the refrigerant passes, wherein the refrigerant flowing into the refrigerant inflow side header tube is mixed with the gas refrigerant flowing in and the liquid refrigerant A heat exchanger characterized in that a gas-liquid diffuser that diffuses and circulates is disposed.   2. The heat exchanger according to claim 1, wherein the gas-liquid diffuser is formed with a plurality of flow holes having small holes enough to mix the gas refrigerant and the liquid refrigerant liquid.   The gas-liquid diffuser is formed in a cylindrical shape having a wire bent and a width in the tube axis direction of the refrigerant inflow portion, and the plurality of flow holes are bent in a wave shape and intersect with each other. The heat exchanger according to claim 1 or 2, characterized in that.   The heat exchanger according to claim 3, wherein the gas-liquid diffuser is formed by bending a wire-like metal wire.   The heat exchanger according to any one of claims 1 to 4, wherein the refrigerant inflow side header pipe has a refrigerant inflow part formed at both ends thereof, and the gas-liquid diffuser is disposed at each refrigerant inflow part. .   The heat exchanger according to any one of claims 1 to 5, wherein the heat transfer tube has a plurality of flow paths formed in parallel therein and formed flat.

Images