JP5540409B2 - Linked pressure heat exchanger and manufacturing method thereof - Google Patents

Description

The present invention relates to a heat exchanger structure and a manufacturing method that improve pressure resistance of a coupled heat exchanger, simplify a manufacturing method, and improve confidentiality.

The present invention is a development and improvement of the connected heat exchanger utility model registration 1199856.

The inventor is the same person, although the address has been changed, and is working hard to improve the problems of the above-mentioned device.

The object of the present invention is to easily produce a plate fin type heat exchanger, lower the manufacturing cost, and further improve the performance (pressure resistance and confidentiality, long life).

In both the above-described device and the present invention, the flow path is a bellows tube and the heat transfer efficiency is about 1.5 to 2.0 times higher than the plate fin type heat exchanger due to the generation of turbulent flow.

The problem with plate fin type heat exchangers is that many U-shaped copper pipes are inserted in order from one side by using a large number of holes in aluminum and opened at the same position. In addition to the necessity, brazing was necessary for joining aluminum and copper, and the loss of efficiency of heat transfer due to inclusions was inevitable.

The problem of efficiency loss due to the heat transfer was completely solved by transforming the fin material of the connected heat exchanger utility model registration 1199856 into a pipe.

However, the problem with the above idea is that the fin thickness should be as thin as 0.1 to 0.5 mm in order to save resources and reduce the weight, and the pipe through which the fluid passes is often about 5 atm or more such as steam or water. Therefore, when a tapered pipe is formed by pressing, the pipe portion becomes thin, and even if only the press position is thickened, it is difficult to manufacture due to deep drawing, and it is easy to leak.

If the pipe part is manufactured using only aluminum, the connection requires brazing such as vacuum brazing (because it is thin and has an oxide film, and TIG welding is difficult). The shortage could not be compensated.

The pressure resistance can be improved by inserting a thin copper pipe and expanding the pipe to increase the strength, but the efficiency deteriorates due to the problem of heat transfer between aluminum and copper, and additional brazing is inevitable.

Utility Model Registration 1199856

In the conventional manufacturing method, it is necessary to insert from the end of the pipe in order from the end of the pipe using an insertion machine, stop at a constant interval, and insert the next fin, and the equipment space is wasted in a long pipe heat exchanger, It was time consuming and expensive.

In the present invention, the problems of the connected heat exchanger utility model registration 1199856 are that the pressure resistance of the bellows flow path is low, the deep drawing of the pipe part is difficult, and it is difficult to braze with the aluminum oxide film. All the points that are easy to leak are improved.

The problem of pressure resistance is due to the fact that the tapered pipe is thin. There is a contradiction that the thinner the plate portion is, the lighter the material can be saved, and the deeper the drawing, the thinner the plate.

Therefore, in the present invention, by inserting one taper spacer C between a plurality of fins in which adjacent tapered pipe parts formed by pressing are alternately projected on both sides of the fin, the interval between the fins A is made constant and the pipe is fixed. The pressure resistance can be increased by increasing the thickness of the portion and performing vacuum brazing fusion.

By pressing, the surface of the part that becomes the aluminum tapered pipe part is thickly copper-plated, the copper pipe is tapered with the press, and aluminum is deposited on it, and sandwiched between the aluminum and copper layers, Become.

In this state, assemble the connected pressure-resistant heat exchanger up to the U-tube at the end, and apply it in a vacuum or in an inert gas stream while applying pressure evenly from both sides of the U-tube using weights vertically. By heating to near the eutectic temperature of copper and aluminum (about 100 ° C lower than the melting point of aluminum), it became possible to manufacture heat exchangers that are fused and have both confidentiality and pressure resistance.

If copper is plated on aluminum, there is no oxidative passivation, and the copper melting point is 1083.4 ° C and the melting point of aluminum is 660.4 ° C. When the vacuum is maintained near a lower eutectic temperature of 548 ° C. and vibration is applied under pressure, bonding proceeds, and the eutectic bonding is further strengthened by heat treatment.

Since the male and female holes can be located at the U-tube interval, a connected pressure-resistant heat exchanger with any fin shape (for example, two-row full circumference (shown in FIG. 4), spiral arrangement, etc.) is possible. It became.

Even if U-tubes are prepared with several kinds of intervals, one kind of each is sufficient, and the assembly work, material arrangement, inventory management, and the number of parts on both sides are conjugate, which helps to reduce the cost.

Since the aluminum fin pipe and the copper pipe are eutectic bonded and heat conduction is good, and turbulent heat transfer in the bellows pipe is achieved, the liquid or gas heat transfer rate is also improved.

Furthermore, an expensive silver-containing paste or welding material called brazing is not required, and since it is a eutectic, bonding can be performed at a temperature lower than the melting points of copper and aluminum, and deformation of the shape can be reduced.

In conventional plate fin manufacturing, an expensive machine that cannot be diverted, such as a copper pipe insertion machine, is unnecessary, and the work is reduced, resulting in a significant cost reduction.

In the direction of the length of the pipe, the number of stacked layers is arbitrary, and design changes and manufacturing changes are easy.

This invention is an epoch-making invention that not only covers all the advantages of the utility model connected heat exchanger utility model registration 1199856 but also eliminates the following drawbacks.

The advantages (12 points in the old draft) are listed below, and the additional benefits (three points) of this draft are further shown.

  1. With a meandering flow path, the number of curved pipes can be changed from F and G to only one type, and the cost of the mold or the spare stock can be halved to reduce the cost.

  2. In the meandering flow path, the alternating press (the present invention) has a low water flow resistance as compared with the one in which the pressing direction is one direction.

  3. You can increase the number of fins to create a free-length heat exchanger.

  4). Thermal efficiency is improved. B) Because of turbulence. B) Because the pipe and fin are the same continuous.

  5. A fin is attached to the bellows tube.

  6). The spacing between the heat sinks (fins) can be made constant.

  7). Fins do not wobble due to brazing and eutectic bonding.

  8). Can be molded with a press, and can be produced at low cost through mass production and automation.

  9. Material can be saved.

10. The shape of the pipe can be set freely, and the layout can be freely set according to the U-tube interval.

11. When assembled and eutectic bonded, the rigidity of the structure increases.

12 There is no need for expensive machines that cannot be diverted, such as copper pipe insertion machines.

Additional benefits of the proposal

13. All the liquid flow paths are made of copper, and the pressure resistance of the pipe can be increased.

14 Due to the eutectic bonding of copper and aluminum, there was no dissimilar material and the decrease in heat transfer rate could be prevented.

15. In the joining of assemblies after pressing, this gravity press eutectic joining is an optimum joining method capable of precision joining without deforming the shape.

The taper spacer C is mainly formed by cutting a copper tube and processing it into a taper shape with a press. The taper spacer C mainly maintains a constant fin interval and secures the pressure resistance and rigidity of the bellows flow path.

Therefore, compared with the previous device, it is possible to secure a sufficient gap between the fins and the fin plate thickness without increasing the deep drawing ratio, and the fin plate thickness can be set thin. The thickness of the tapered tube is set independently of the fin thickness. The pipe part can be made of copper independently of the fin material (mainly aluminum), ensuring strength and rigidity.

Since the fin aluminum plate becomes difficult to weld or braze when its surface is oxidized, it is pressed after a copper coating is applied in a vacuum by ion plating, vapor deposition, plating, or the like.

Nitrogen gas for prevention of oxidation in a state where the pressed fin A and the tapered spacer C are overlapped, and one kind of U-shaped pipe H connecting both ends and an inlet and outlet pipe are attached and pressurized from above and below by gravity. In an electric furnace such as an inert gas, it is heat-formed to the eutectic temperature.

When bonding is performed by energization or induction heating with a brazing agent in between, it can be produced even at a lower temperature.

Since the pressure resistance of the present invention is improved as described above, it is possible to flow a high-pressure liquid such as a refrigerant or a gas, and the utility value as a heat exchanger is increased.

The present invention can be used for cooling by passing groundwater and sending wind with a fan, and can be used for heating by sending wind with steam through a steam. Furthermore, heat exchange for heat pumps and chillers It can also be used as a container.

It is made to protrude alternately in the order of the flow path in which only the press hole interval is constant. (The cross section is shown in FIG. 2)

The folded plate fin heat exchanger (Fig. 3) that surrounds the sirocco fan in a U-shape, which is common in current wall-mounted air conditioner type heat exchangers, is also tapered from the fins in the connected pressure-resistant heat exchanger of the present invention. When the pipe part is pressed, the part where the sirocco fan enters and the outer shape are formed at once, and the copper taper spacer C is sandwiched by a predetermined thickness so that no bending process or holding device is required, and the manufacturing process Simplified. (Shown in Figure 4)

In this way, there is no need to insert the copper pipe into the fin from one side, and the position can be determined when designing the press die, so that there is an advantage that no insertion machine is required and the design change of the size and shape can be simplified.

Examples of conventional connected heat exchanger utility model registration 1199856. Sectional drawing and the partially expanded view along the meandering flow path of this invention. (Example 1: cf. Gas is perpendicular to the paper surface along the fin) A side sectional view of the conventional bending heat exchanger (the exterior part is shown as a partial section). 1 is a side sectional view of the present invention (a part of an exterior portion is shown as a cross section). (Example 2)

A: A heat sink (plate fin) is shown.
B: Indicates a tapered pipe (old: deep aluminum drawing / new: aluminum press alternating drawing).
C: represents a copper taper spacer (a copper tube is tapered by pressing).
D: The female hole end (for flange hole) part is shown.
E: Male hole end (B taper pipe / C taper spacer) inner end portion.
F: U-shaped connecting pipe with male holes at both ends (illustrated in old utility model) not shown this time.
G: U-shaped connecting pipe with female holes at both ends (illustrated in old utility model).
H: A U-shaped connecting pipe having both male and female holes.
I: External casing cross section (material plastic, etc.)
X: Indicates the direction of fluid flow.
Y: Cross follow fan

Claims (2)

Adjacent taper pipes protrude alternately on both sides of the aluminum fin, and a large number of the fins are laminated and connected to the laminated end using a copper U-shaped connecting pipe with both male and female tapered ends. A copper taper spacer C of the same angle with a brazing agent is inserted between each tapered pipe part of the heat exchanger, and a brazing process is performed while pressing the joint surface uniformly by gravity. the method of articulated withstand heat exchanger to the internal pressure reinforcement structure of serpentine flow paths.
Adjacent taper pipes protrude alternately on both sides of the aluminum fin, and a large number of the fins are laminated and connected to the laminated end using a copper U-shaped connecting pipe with both male and female tapered ends. Copper tape is applied to both sides of each taper pipe part of the heat exchanger, and one copper taper spacer C in which aluminum vapor deposition is formed between the fins is inserted, and sympathetic joining is performed together with pressure by gravity. Articulated pressure heat exchanger.

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