JPS5947233B2 - Heat exchanger using flat tubes with U vents - Google Patents

Description

Detailed Description of the Invention The present invention relates to a heat exchanger using a flat tube having one U-bend, which has a small number of parts, is easy to assemble, and has low flow resistance at the U-bend. It is an invention aimed at obtaining.

As shown in FIG. 1, when forming the U-bent 1 part 2 in a flat tube 1 used in a heat exchanger, if the U-ben 1 part is formed by bending the flat tube 1 in the major diameter direction of its cross section, As shown in Figure 2, wrinkles occur on the inside of U-ben 1 part 2, and the outside becomes thin due to tension and cracks are likely to occur, and the internal cross-sectional area of U-ben 1 decreases, increasing flow resistance. Resulting in.

In addition, when forming the U-bent 1 part by curving a flat tube in the short diameter direction of the cross section, the outer tube wall 1a is pulled inward and concave, as shown in Fig. 3, and the internal cross-sectional area is reduced. U Ben 1
There was a disadvantage that the distribution resistance in the section became large.

The heat exchanger according to the present invention is an effective heat exchanger that does not cause these disadvantages and uses a flat tube that can form a U-ben part with a smaller radius than the conventional one.

The present invention will be explained below with reference to FIG. 4 showing an embodiment.

4 to 6 show the shape before processing of a flat tube having a U-bend used in the heat exchanger of the present invention, and this flat tube consists of a circular tube section 3 and a flat tube section continuous on both sides of this circular tube section 3. 4,4.

When forming the U-bent F part in such a heat exchanger tube, the circular tube part 3 is bent to form the U-bent part 2, and this bending is done in the direction perpendicular to the plane of the paper in FIG. shall be bent.

As a result, a U-bent pipe as shown in FIG. 7 is obtained, in which the major axis of the cross section of the flat tube section 4 is parallel to the plane of the paper and the two flat tube sections 4 are in the same plane.

The cross-sectional shape of the first part of the U-ben is approximately circular.

For the heat exchanger tube having one part of the U-bent, in addition to bending a straight pipe having a shape as shown in FIG. The flat tube portion 4 may be formed by compressing the straight tube portion.

Further, the side surface of the U-ben 1 portion may remain a circular tube or may be flattened by pressing.

In this way, since the cross-sectional shape of the curved part of the U-bent pipe is circular, the radius ratio between the outside and the inside is relatively small compared to the case where the flat pipe is directly bent as shown in Figures 1 to 3. Since it is small and circular, its strength is large, so there is little change in the cross-sectional shape when bending, so the cross-sectional area of the pipe is small; therefore, the flow resistance at the first part of the U-ben becomes unnecessarily large. There is no cracking on the outside.

8 and 9 illustrate a heat exchanger of the present invention manufactured using a flat tube having the U-ben F portion formed as described above, and the heat exchanger formed as shown in FIG. 7. A plurality of U-bend pipes 5 are made using a U-bend F pipe 5 having a U-bend r part 2 formed by flat pipe parts 4, 4 and a circular pipe part 3, and the side surface of the circular pipe part 3 is made flat by pressing or the like. . Open inside 6.

The lower tank 6 is divided into two chambers by a partition wall 6a,
Inlet pipe 9 in one room and outlet pipe 10 in the other room
It is attached.

Reference numeral 7 denotes a side member that tightens and fixes the plurality of pipes 5, 5 from both sides.

The side member 7 can be omitted. Further, the side surfaces of the circular tube portions 6 which are continuous with each other may not be flattened as shown in FIG. 8, but may be brought into contact with each other in their circular cross-sections, and then connected by brazing.

Figure 10 shows U-V tubes 5 arranged in parallel as shown in Figures 8-9.
An example of a heat exchanger constructed by arranging two sets of is shown.

Two partition walls 6a and 6b are provided to divide the inside of the lower tank 6 into three parts, and two sets of U-bend pipe rows are operated in series.

In this way, the flat tubes having U-bent parts are arranged in parallel,
The heat exchanger of the present invention in which the lower tank 6 is connected has an inflow pipe 9
When high-temperature fluid (for example, boiling water) or refrigerant is fed into the lower tank, these fluids enter one end of the U-bent pipe from the lower tank and flow to the other end, passing through the flat pipe parts 4, 4 and flowing into the lower tank. It enters the tank 6 and exits through the outlet pipe 10.

During that time, the fluid flowing through the U-shaped tube is cooled by exchanging heat with other fluid such as air flowing between the fins 8, or the air flowing between the fins is cooled by flowing a refrigerant through the U-shaped tube. Cooling.

This heat exchanger is constructed by connecting U-bend pipes side by side and connecting them to a lower tank with a partition wall, so it can be manufactured easily and firmly. Since the tube is bent as a circular tube instead of being bent, the flow resistance at the U-bent portion is small, and an efficient heat exchanger can be provided.

[Brief explanation of the drawing]

Figures 1 to 3 are diagrams showing flat tubes processed using the conventional method. Figure 1 is a front view, Figure 2 is a sectional view taken along line A-A in Figure 1, and Figure 3 is a diagram showing a flat tube processed by the conventional method. Similar sectional views, Figure 4 and the following are views showing embodiments of the present invention, Figure 4 is a front view showing the heat exchanger tube before bending, Figure 5 is a BB sectional view of Figure 4, and Figure 6 is a front view showing the heat exchanger tube before bending. The figure is also a C-C sectional view, Figure 7 is a front view showing the state after bending the tube in Figure 4 in a direction perpendicular to the plane of the paper, and Figure 8 is a tube manufactured using the above U-bend tube. A front view showing an embodiment of the heat exchanger of the present invention, FIG. 9 is a cross-sectional view taken along line DD in FIG. 8, and FIG. 10 is a cross-sectional view similar to FIG. It is a diagram. 1: Flat pipe, 1a: Pipe wall, 2: U vent part, 3: Circular pipe part, 4: Flat pipe part, 5: U Ben F pipe, 6: Lower tank, 6
a, 6b: partition wall, 7: side member, 8: fin, 9:
Inlet pipe, 10: outlet pipe.

Claims (1)

[Claims] 1 The bending part of the U-shaped tube is bent into a circular tube, and the straight parts on both sides are compressed parallel to the U expansion surface to make a flat tube part.
A plurality of flat tubes having bends are connected in parallel by abutting one part of the U-bent, both ends of the flat tube section are tightly fitted and connected to a lower tank, and a partition is provided in the lower tank to separate both ends of the flat tube section. A heat exchanger using a flat tube having a U-bent portion with an inlet pipe and an outlet pipe communicating with a lower tank partitioned by the partition wall.