JPH0284252A - Heat exchanger tube and its manufacture - Google Patents

Abstract

PURPOSE:To manufacture the heat exchanger tube whose pressure resisting performance and heat transfer property are excellent by superposing and depositing two pieces of plate materials having plural produced teeth so that they are opposite to each other and forming plural passages. CONSTITUTION:With respect to plate materials 1a, 1b provided with plural pieces of teeth 3 protruded continuously in the longitudinal direction and at a prescribed interval on one face of a metallic piece which is like as band and consists of thin Al, etc., the plate material 1b is superposed on the plate material 1a in parallel so that the teeth 3 are opposite to each other. By allowing them to pass through a heating furnace 4, the plate material 1a and 1b are deposited completely, the protruded teeth 3 are stuck, and a partition plate 7 for forming plural pieces of passages 6 is obtained. The passage of a heat exchanger tube 1 is not extruded simultaneously to a front shape nor brought to drawing but formed by dividing the plate material, therefore, wall thickness of the plate material can be worked thinly, and also, height (a) of the heat exchanger tube can be set <=3mm. Also, the heat transfer performance can also be improved by plural passages 6 generated by the partition plate 7.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat exchanger tube used in a heat exchanger in front of air conditioners, refrigeration equipment, and automobile equipment, and a method for manufacturing the same.

BACKGROUND OF THE INVENTION In recent years, flat tubes used in automobile radiators and serpentine type heat transfer tubes used in automobile air conditioners have become well known as heat transfer tubes of this type.

A conventional heat exchanger using a flat tube of this type uses a flat tube 51 as shown in FIGS. 10 and 11, and a fin 52 is joined between the flat tube 61 bent, thereby forming a heat exchanger. It consisted of

In addition, in the case of the serpentine type, the external shape as a heat exchanger is the same as that shown in Figure 11, but as a heat exchanger tube, there are girders inside to improve pressure resistance and heat transfer characteristics, as shown in Figure 12. It was common to use an extruded aluminum tube 63 with a plurality of tubes.

Problem to be Solved by the Invention However, when the heat exchanger using the flat tube 61 described above is used as a condenser using a refrigerant, the pressure inside the tube is 15
~20 kp/cd, which caused problems in terms of pressure resistance, such as expansion near the center, peeling off of the joints with the fins 52, or, in severe cases, cracks in the heat exchanger tubes.

In addition, in the case of the survein tine □ type, it is manufactured by extruding aluminum, so if the wall thickness of the tube 63 is made too thick or the height h is made too low, it may break during extrusion. Wall thickness and height h are required. (Especially for this type of heat transfer tube, it is difficult to manufacture a height of 3 mm or less.) This results in the problem that the heat resistance of the tube increases and heat transfer performance increases, and also the problem that ventilation resistance cannot be kept small. there were.

SUMMARY OF THE INVENTION In order to solve these problems, the present invention aims to provide a method for manufacturing a heat exchanger tube and a heat exchanger tube with excellent pressure resistance and heat conductivity using a simple method.

Means for Solving the Problems In order to achieve this object, the heat exchanger tube and its manufacturing method of the present invention provide a thin strip-shaped metal plate with a plurality of continuously protruding teeth on one side thereof at regular intervals in the longitudinal direction. The two boards that were
The plate surfaces are parallel to each other, the @-marked teeth face each other and are welded to form a plurality of channels, and the height between the plates is 3 or less. The manufacturing method consists of two plates extruded or pultruded so as to have a plurality of teeth protruding in the longitudinal direction on one side of a band-shaped metal plate;
The plate materials are stacked so that the teeth face each other and are sent into a heating furnace to heat the plate material and melt the wax foil, and at the same time press or roll from above and below. The plates are then welded to form a plurality of flow channels to provide a predetermined height between the plates.

Function With this structure, the plate material is formed by welding into a strong, thin-walled, heat-conducting, and one-piece body, and this method also allows for a process that would be difficult to achieve with conventional manufacturing methods, which involve only extrusion and pultrusion. By making it possible to supply heat exchanger tubes with thinner walls and lower heights, and by increasing the number of flow channels, it is possible to improve pressure resistance and heat transfer performance, and reduce ventilation resistance.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 shows the constituent materials of a heat exchanger tube in a first embodiment of the present invention. In Fig. 1, two plate materials 1a are provided with a plurality of teeth 3 that continuously protrude at regular intervals in the longitudinal direction on one side of a thin band-shaped metal plate made of aluminum or the like.
and 1b are formed by extrusion or drawing, and then the plate material 1a is stacked in parallel with the plate material 1b with the wax foil 2 in between so that the teeth 3 face each other. At this time, the plate material 1a
and position so that the apex of the protruding tooth 3 of 1b becomes the joint. Next, as shown in FIG. 2, the stacked plates 1a and 1b are passed through a heating furnace 4. The temperature inside the heating furnace 4 is controlled to be higher than the melting temperature of the wax foil 2,
By applying pressure and rolling in the vertical direction with the roll 5, the plates 1d and 1b are completely welded together, the protruding teeth 3 are brought close to each other as shown in FIG. 3, and a plurality of channels 6 are formed.
The partition plate 7 forms the As described above, instead of extrusion or pultrusion molding to the front shape of the flow path of the heat exchanger tube 1 as shown in FIG. Moreover, the height d of the heat exchanger tube can be reduced. Moreover, the pressure resistance is increased by the partition plate 7 compared to a normal flat tube, and the heat transfer performance is also improved by the plurality of flow paths 6 created by the partition plate. This is because the heat flux (hl/m'h-K) increases.

Generally, the heat transfer coefficient is expressed by the following formula.

Here, FSA: Air side surface area (m') FSR: Refrigerant side surface area (,,') αa: Air side heat transfer coefficient (lcaL/-"・h-K)φ
:Fin efficiency αR: Refrigerant side heat transfer coefficient (1cal/m”h @K)
Thermal resistance of the γ-tube (m"b-/hl) As is clear from the above equation (1), if the ratio FsA/FsR of the air side surface area FSA and the refrigerant side surface area FsR is decreased, the heat transfer coefficient will increase. becomes larger.

Compared to conventional flat tubes, the partition plate 7 allows for the same outside tube area F.
Even in SA, since the pipe inner area FRA becomes larger, the heat transfer coefficient K becomes larger when the pipe inner/outside area ratio FsA/FRA is smaller.

Also, compared to the serpentine type, the wall thickness can be made thinner, so the thermal resistance γ is smaller. Furthermore, since the plurality of flow paths 6 are formed by partition plates, the equivalent pipe diameter is small and αR is large. From the above, the heat transmission coefficient is further increased, which has the effect of improving heat conductivity.

A second embodiment will be explained with reference to FIGS. 4 and 6.

In Fig. 4, a plate material 8 is provided with a plurality of teeth 9a continuously protruding at regular intervals in the longitudinal direction on one side of a thin band-shaped metal plate such as aluminum; A plate material 8b having a plurality of protruding teeth 9b of the same size provided at intermediate positions of the plurality of protruding teeth 9a of the plate material 8a is formed by extrusion or drawing, respectively. The plate material 8a and the plate material 8b are made to face each other so that their teeth 9a and 9b face each other,
A solder foil 1o for welding is inserted in the middle. Since the teeth 9a of the plate 8a fit between the teeth 9b of the plate 8b, the wax foil 10 needs to be long with respect to the width of the heat exchanger tube. The plate material 8a and the plate material 8b are welded by heating in a heating furnace, and by pressurizing or rolling, each of the plurality of teeth 9a shown in FIG.
9b is welded to form a heat transfer tube 9 having a plurality of channels 11. The feature of the structure in which the other teeth 9bi are alternately inserted between the teeth 9a is that the number of flow paths can be increased. Plate materials 8a and 8b
When extruding or pultrusion molding, the distance between the teeth (partition plates) cannot be kept very short. Therefore, in the case of overlapping as in the first embodiment, the number of channels does not change much, but by welding one tooth between another tooth, the number of channels is doubled. By increasing the number of flow paths, the equivalent pipe diameter becomes smaller (lR becomes larger), which has the effect of improving heat conductivity.

A third embodiment will be described with reference to FIGS. 6 and 7. Ends on both sides of plates 8a and 8b (12a to 12d)
It is rounded and formed by extrusion or drawing. As an effect of this, by improving the flow of the air 14 as shown in FIG. 7, the ventilation resistance VC can be further reduced, α0 can be increased, and the heat transfer coefficient Ki can be further improved.

An embodiment of the funeral 4 will be described with reference to FIGS. 8 and 9. When the plate materials 15a and 15b are extruded or pultruded, a large number of projections and depressions 16 as shown in FIG. 8 are completely formed. As an effect of this, it is possible to further increase the tube inner area FSR9 and further improve the heat transmission coefficient K.

As described above, since the component parts of the heat exchanger tube of the present invention are formed by dividing the plate material and extruding or pultruding it, the thickness of the plate material can be thinned and the height of the heat exchanger tube can be reduced, and the height of the heat exchanger tube is 3 mm or less. Heat tubes can be manufactured easily. Furthermore, by forming a plurality of flow paths, it is possible to reduce ventilation resistance, improve pressure resistance performance, and improve heat transfer performance.

In this embodiment, the number of channels is shown as 7 to 8, but it goes without saying that by changing the number and spacing of teeth, the number of channels can be increased and performance can be improved.

Effects of the Invention As described above, according to the heat exchanger tube and the manufacturing method thereof of the present invention, two plates each having a plurality of protruding teeth are formed by extrusion or pultrusion through a solder foil for welding. By stacking plates so that the teeth face each other and melting and welding wax foil to create a heat transfer tube with multiple channels, we can provide thin-walled, low-height heat transfer tubes that are difficult to achieve with conventional methods. By increasing the number of flow channels, pressure resistance and heat transfer properties can be improved, ventilation resistance can be reduced, and great practical effects can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the structure of a heat exchanger tube according to an embodiment of the present invention, FIG. 2 is a schematic diagram of processing and welding of the heat exchanger tube, and FIG.
The figure is a front perspective view of the flow path of the heat exchanger tube, and the figure is a perspective view of the main part of a conventional heat exchanger tube. 1a, 1b, sa, sb, 1sa, 1sb --- Plate material, 2, 10 --- Wax foil, 3, 9a, 9b, 1
6...Teeth, 4...Heating furnace, 5...
...Roll, 6...Flow path.

Claims (6)

[Claims] (1) Two thin strip-shaped metal plates each having a plurality of successively protruding teeth arranged at regular intervals in the longitudinal direction on one side are welded so that the plate surfaces are parallel to each other and the protruding teeth face each other. A heat exchanger tube in which a plurality of channels are formed by using a plurality of plates, and the height between the plates is 3 mm or less. (2) On one side of the band-shaped metal plate, two plates formed by extrusion or drawing so as to have a plurality of teeth protruding in the longitudinal direction are placed through a solder foil for welding so that the protruding teeth face each other. A method for manufacturing a heat transfer tube, in which the plate materials are stacked on top of each other, sent into a heating furnace, the plate materials are heated and the brazing foil is melted, and pressure is applied from above and below to weld. (3) The heat exchanger tube according to claim 1, wherein the two plates have similar shapes and dimensions, and the protruding teeth are formed by welding the tops of each other. (4) A plurality of protruding teeth of the two plates are arranged at regular intervals between both ends of one of the plates,
2. The heat exchanger tube according to claim 1, wherein the other plate member is disposed at an intermediate position between the teeth with a similar protruding dimension, and the tops of the teeth are welded to both plate parts. (5) The heat exchanger tube according to claim 1, wherein the corners at both ends of the two plates are rounded. (6) The heat exchanger tube according to claim 1, wherein a large number of projections and depressions are formed on the inner surfaces of the two plates forming the flow path.