JPS58164995A - Heat exchanger and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain the heat exchanger using a multiholed flat pipe which guarantees an accurate and strong connection and to provide the method of manufacturing same by a method wherein the partition wall of the flat pipe is bent in the inner longer diametral direction and the length of the partition wall in the inner shorter diametral direction is made longer than the inner shorter diameter of the flat pipe. CONSTITUTION:The multiholed flat pipe 1 is extrusion molded generally by the use of Al or an Al alloy in such a configuration that when it is assembled into the heat exchanger, the side walls 3 and 4 coming into contact with a corrugated fin when assembled are divided into parallel elongated continuous flow passages 6 by doggled partition walls 5 interposed therebetween in the direction parallel to the side walls. The partition wall 5 may be formed in various configurations such as chevron or S and etc., and it is sufficient that the partition wall 5 is bent in the inner longer diametral direction so that the total length of the length l1 of the front and that l2 of the back of a bent point 8 is made longer than the inner shorter diameter L, that is, the distance between the inner surfaces of the side walls 3 and 4. Thus, in the case of such flat pipe, when the bent partition walls 5 are expanded to make them linear or substantially linear by using pinchers, the side walls 3 and 4 are expanded sidewardly by being thrusted by the partitioned walls and the inner short diameter L of the pipe 1 is expanded to L'.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is characterized in that flat tubes and corrugated fins are alternately laid out in parallel, and drinking holes corresponding to the flat tubes are formed at both ends of the tube sheet metal. flattened by brazing
Regarding the flat tubes used in the heat exchanger core formed by joining the corrugated fins and the Miyani fins together, and the method of assembling the same as a heat exchanger, in particular, we aimed to make it possible to easily and reliably join the 1lIIlf tubes. related to things.

In the above-mentioned brazing operation, if the gap between the fitting hole of the tube sheet and the outer periphery of the flat tube is large, the solder will not wrap around the tube sufficiently, resulting in poor bonding. However, in order to reduce the gap between the blades, the forming process of the flat tube, fitting hole, and corrugated fin requires strict processing with strict tolerances, and in addition to inserting the flat tube into the signboard, filing work is required. It takes a lot of effort.

On the other hand, for circular pipes or flat pipes that do not have many holes, it is possible to expand the temporarily inserted end of the pipe by simple engineering to reduce the gap between the fitting hole in the tube plate and the outer circumference of the pipe. In conventional multi-hole flat tubes that have partition walls as internal fins to improve thermal performance, the corner walls have a board with strong ribs.
Even if an attempt was made to reduce the gap after inserting the flat tube into the signboard, the flat tube would not be enlarged at each station, resulting in poor water contact.

In addition, in order to further improve the heat transfer performance of multi-hole flat tubes, it is necessary to widen the contact area between the partition walls and the internal fluid. Because the shape of the partition walls that make the partition walls protrude is complicated, manufacturing techniques are difficult and expensive extrusion molds are required.

The present invention has been devised in view of these points, and uses a multi-hole flat plate that can be expanded with extremely simple operations and that can provide a reliable and strong rest against the tube sheet. In short, we aim to provide a heat exchanger and a method for manufacturing the same, in short, we will open and flatten the entire partition wall that becomes the internal fins of the flat tube.
For example, if you use a multi-hole flat tube with a double-shaped spacer, and insert this flat tube into a temporary fitting hole, By squeezing the bent bulkhead at the end, the bulkhead in that area is suddenly moved outward, causing the outer wall of the flat tube connected to the bulkhead to bulge outward. The present invention provides a heat exchanger that has a small gap with the tube sheet, thereby making the subsequent brazing work reliable and robust, and has a high heat exchange rate, and a method for manufacturing the same.

Next, embodiments embodying the present invention will be described with reference to the attached drawings. Here, FIG. 1 is a front view of a multi-hole flat tube that can be used in a heat exchanger according to an embodiment of the present invention, and FIG. 2 is a front view of the same flat tube before and after expansion. Fig. 3 is an exploded perspective view of the heat exchanger core using the flat U type, Fig. 4 is a partially cutaway view of the heat exchanger, and Fig. 5 a) to (f) are front views showing modified examples of the flat tube.

As shown in FIG. 1, the multi-hole flat tube (1) used in the present invention has side walls (3) that come into contact with corrugated fins when assembled.
A bulkhead (5) with a dogleg-shaped cross section and (4) sandwiched therebetween.
, (5), ... connected with side m 131 and (
4) is the flat space between the partition walls (5), (5),...
・Parallel flow path +61, i61, etc. #4 No meeting, paper gap.

It is a long continuous piece in the vertical direction, and is generally formed by extrusion of aluminum or an aluminum kettle.

The shape of the bulkhead (5) is the shape of the letter S, the letter S, and the letter S.
Other divine objects such as bellows-shaped bends in multiple stages can be considered, but in short, the total length measured in the past (in the example shown in the first diagram, the length before and after the bending point (8)) is attached to the side (7). el) and (e2)) is the flat tube (5
) The shape should be bent in the longitudinal direction of the flat tube so that it is longer than the short diameter υ (igll wall + 31, distance of the inner surface of (4)), and furthermore, the fin should protrude in a branch shape from the side surface. It may be a structure. The direction of bending of the partition wall is preferably symmetrical to the left and right with the center in the longitudinal direction of the flat tube as a boundary, as shown in the first figure. This is because there is less distortion during the pipe expansion work described below.
FIG. 5 illustrates various shapes of such partition walls. (
9) is a fin protruding from the side wall or partition wall to increase heat transfer efficiency.

In such a flat tube, when the bent partition wall (5) shown by the caustic line in Fig. 2 is placed directly or stretched into a nearly straight state as shown by the broken part with pliers, the 3) and (4) are placed on the partition wall and cast shadows to the sides as if they were broken and look like they are broken, and the side wall (3)
) and (4) with the same short axis ←) are expanded like ←).
The heat exchanger manufacturing method of the present invention focuses on the special effect of such a flat tube having nine bent partitions.
As shown in the figure, first, the corrugated fins a1 and the multi-hole flat tubes (1) having the above-mentioned bent partition walls are laminated in parallel alternately, and then the tube plates (lυ, 011) are stacked on the flat tubes +11, +11, .
... and insert each tube end into the fitting hole tea, +121, ... of the tube plate Qll, uυ. After that, the gap between the end tube part of the flat tube inserted into the tube plate U9
, 15) are bent on a bench or the like in the direction in which they are bent and stretched as shown in FIG. As a result of this operation, the flat tube bulges to one side as described above, and the gap between it and the fitting hole of the tube plate becomes narrower. Therefore, such a partition wall stretching operation may be carried out only at the wide gap portion, and may not be carried out only at the tube end. , (13 is corrugated fin (
111) and the flat tube (11), which is a side plate that covers the side of the core d4, which is provided at the side plate and the fluid inlet/outlet part. After that, the whole thing is put into the furnace and brazed.

The above-mentioned expansion of the flat tube may be performed immediately after the flattening/U is formed on the tube plate, but it may also be performed at the stage when the core is assembled to the wax elbow jig.

As described above, the present invention is made by laminating alternately parallel multi-hole flat tubes and corrugated fins in which the inside of the flat tube is divided into a plurality of parallel flow paths by a plurality of partition walls provided in the flat tube made of gold JI14. The sex exchanger is characterized in that the partition wall of the flat tube is bent in the long axis direction of the flat tube, and the length of the partition wall in the inside short axis direction of the flat tube is longer than the inside short axis of the flat tube. Since this is a manufacturing method for heat exchangers and heat exchangers in which the tubes are expanded by stretching the partition walls of the flat tubes, it is extremely easy to expand the multi-hole flat tubes at the assembly site, and it is possible to reliably produce a robust heat exchanger. Moreover, the bending of the Ffh wall increases the contact area between the partition wall and the fluid in the pipe, thereby providing a heat exchanger with extremely good heat transfer efficiency.

[Brief explanation of the drawing]

Figure 1 is a front view of a flat tube showing an example of a multi-hole flat tube that can be used in a heat exchanger that can be used in a heat exchanger according to an embodiment of +: investigation, and Figure 5g2 is an enlarged view of the same flat tube. rjtl case IPJ
FIG. 3 is a perspective view of a heat exchanger core using isothermal flat tubes, FIG. 4 is a partially cutaway perspective view of the same heat exchanger, and FIG. 5 is an enlarged front view showing A. It is a front view which shows various modification examples of the said flat tube. (Explanation of symbols) 1... Multi-hole flat tube, 5... Partition wall, 6... Channel, 10... Corrugated fin, 11... Tube plate, 1
2... Fitting hole, 13-' side plate, 14... Core,
L: Inner short diameter of the flat tube. Person Kobe Steel Next Generation i: Gate Patent Attorney Takeji Honjo

Claims (1)

[Scope of Claims] 1. A heat exchanger in which corrugated fins and multi-hole flat tubes are alternately stacked in parallel, with the flat tube divided into a plurality of parallel flow paths by a plurality of partition walls provided in the flat metal tube. In,
A heat exchanger characterized in that the partition wall of the flat tube is bent in the inner diameter direction of the flat tube, and the length of the partition wall in the inner minor axis direction of the flat tube is longer than the inner minor axis of the flat tube. 2. The heat exchanger according to claim 1, wherein the bending directions of each partition wall are symmetrical with respect to the center in the longitudinal direction of the flat tube. 3. A multi-hole flat tube in which the inside of the flat tube is divided into a plurality of parallel flow paths by a plurality of partition walls provided in the metal flat tube, the partition walls being bent in the long diameter direction of the inside of the flat tube, and the partition walls having a short length inside the flat tube. Multi-hole flat tubes whose radial length is longer than the inner short diameter of the flat tube and corrugated fins are alternately stacked, and after stacking the outermost layer with a side plate, the flat-V end is attached to a U plate. In addition to matching the drilled mating hole, the Toshijoki 1v11 Haji! By stretching the newspaper part of the shoulder part, the flat tube is expanded in the inner short diameter direction, and the expanded part is densely layered in the fitting hole, and then the entire core is attached by brazing. How to install a heat exchanger.