JPH0474099B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a heat exchanger that has a low pressure loss of fluid passing through the interior and is highly efficient, and is used mainly for cooling liquids, etc., and its manufacture. Regarding the method.

[Conventional technology]

FIG. 6 shows a cross section of the main part of the heat exchanger 10 used for cooling seawater. As shown in the figure, fin plates 1
A copper outer tube 13 with 2 formed inward is placed, seawater is passed through the inner tube 11, and the outer tube 13 and the inner tube 11 are connected to each other.
It was designed to cool the seawater by passing a refrigerant between them.

[Problem to be solved by the invention]

The outer tube 13 in which the fin plates 12 are formed radially inward is manufactured by hot isostatic extrusion or hot forging, so even if it is possible to manufacture a small diameter tube, In the case of a radial pipe, it is difficult to manufacture the pipe with sufficient height for the fin plates that project radially inward.

Of course, even large-diameter pipes can be manufactured as long as the height of the fin plate is low, but in this case, the cross-sectional area through which the refrigerant passes is reduced, resulting in a problem of increased pressure loss.

Therefore, as a result of intensive research, the inventor of the present invention found that it is possible to form a high fin plate by manufacturing the fin tube with the fin plate on the inside from aluminum (including aluminum alloy). I found out something.

However, if the fin tube is made of aluminum, it is strong against refrigerants such as Freon gas, but if it is exposed to seawater etc. from the outside, the outside is likely to corrode due to the salt contained in it, and the aluminum at the end There was a problem in that it was difficult to weld different metals together.

The present invention has been made in view of these circumstances, and provides a heat exchanger that has low pressure loss, can be manufactured at low cost even in large diameters, and has further improved efficiency than conventional heat exchangers, and a method for manufacturing the same. The purpose is to provide

[Means to solve the problem]

The heat exchanger according to claim 1, which meets the above object, comprises a titanium inner tube having an inlet and an outlet, and a large number of fin plates whose tips abut on the outside of the titanium inner tube. An aluminum fin tube with a radial cross-section protruding inward, and a corrosion-resistant and corrosion-resistant fin tube that is disposed in close contact with the outside of the fin tube and has an inlet and an outlet for a refrigerant or heating medium at both ends, respectively. The fin plate has an outer tube made of a metal with good weldability, and the fin plate has an uneven surface and is compressed in the radial direction and pressed against the inner tube.

Further, the heat exchanger according to claim 2 is the heat exchanger according to claim 1, wherein the outer tube is a copper tube, and copper joints are connected to both ends of the outer tube. A titanium-copper cladding is used in the middle for the sealing part of the joint and the inner tube made of titanium, and the whole is tightly joined by welding.

The method for manufacturing a heat exchanger according to claim 3 includes a titanium inner tube having a predetermined diameter, an aluminum fin tube with radially formed fin plates inside, and a copper or copper alloy fin tube. An outer tube is manufactured, first a fin tube is inserted inside the outer tube and passed through a die to reduce its diameter, and then the above-mentioned inner tube is inserted into the reduced diameter fin tube with a gap in between. Then, the whole is passed through a die to further reduce the diameter, and then predetermined joints are joined to both ends.

In addition, the method for manufacturing a heat exchanger according to claim 4 includes a titanium inner tube having a predetermined diameter, an aluminum fin tube with radially formed fin plates inside, and a copper or copper alloy fin tube. An outer tube is manufactured, and the inner tube is first inserted into the fin tube, passed through a die to reduce its diameter, and the fin plate is pressed against the inner tube.Then, the reduced diameter fin tube is inserted into the outer tube. The outer tube is passed through a die and pressed against the fin tube, and then joints are joined to both ends.

Here, aluminum includes pure aluminum and aluminum alloys, and copper includes copper and copper alloys.

[Effect]

In the heat exchanger according to claim 1,
Since aluminum is used for the fin tube, it is easy to manufacture a fin tube with a fin plate that is high in radial height and has an uneven surface, which reduces pressure loss and improves heat exchange efficiency. and will improve.

Since the fin plate is compressed in the radial direction and is in contact with the inner tube, heat transfer efficiency can be improved, and the outer side of the fin tube is made of a metal tube with good corrosion resistance and weldability. Since the outer tubes are arranged in close contact with each other, this protects the aluminum fin tube and ensures corrosion resistance.

Next, in the heat exchanger according to claim 2, the outer tube is a copper tube, a copper joint is connected to the end, and a titanium-copper cladding is used to connect the joint and the inner tube. Therefore, by welding the outer pipe and the joint, welding the copper part of the titanium-copper cladding, and welding the titanium part of the titanium-copper cladding to the inner pipe, the connection between the outer pipe and the inner pipe is The seal is made completely.

In the method for manufacturing a heat exchanger according to claim 3, an inner tube, a fin tube, and an outer tube are manufactured in advance, and the fin tube is first inserted into the outer tube to reduce the diameter of the whole. Since the inner tube is placed inside the diameter-reduced fin tube to further reduce the diameter, the fin tube can be brought into contact with the inner tube in a pressed state, thereby improving heat exchange efficiency. Further, since aluminum is used for the fin tube, a fin tube with a long fin plate can be easily manufactured by extrusion molding, and a large-sized heat exchanger can be easily manufactured.

In the method for manufacturing a heat exchanger according to claim 4, the fin plate is manufactured in a state where it is pressed against the inner tube, and the outer side of the fin plate is further pressed by the outer tube, so that the heat exchange efficiency is improved. Since aluminum can be easily formed, large-sized heat exchangers can be manufactured.

〔Example〕

Next, embodiments embodying the present invention will be described with reference to the attached drawings to provide an understanding of the present invention.

Here, FIG. 1 is a sectional view of the main parts of a heat exchanger according to an embodiment of the present invention, FIG. 2 is a plan view of the heat exchanger, FIG. 3 is a side view of the heat exchanger, and FIG. FIG. 4 is a partial sectional view of the heat exchanger, and FIG. 5 is a flow chart showing the manufacturing process of the heat exchanger.

As shown in FIG. 1, a heat exchanger 15 according to an embodiment of the present invention has an aluminum fin tube 17 disposed outside an inner tube 16 made of titanium, and copper or a copper alloy (for example, 10 %Ni90%Cu) is arranged.

The fin tubes 17 are arranged radially and have a large number of fin plates 21 each having an uneven surface and a support tube 22 that supports the fin plates 21 from the outside. 16 in a pressed state.

The manufacturing method of this heat exchanger 15 will be explained with reference to FIG.
Manufacture. Here, it is assumed that linear irregularities are formed on the side surface of the fin plate 21 inside the fin tube 17 in the drawing direction, as shown in FIG.

First, an outer tube 18 made of copper is attached to the outside of the fin tube 17. In this case, the inner diameter of the outer tube 18 is made larger than the outer diameter of the fin tube 17 by about 1 to 2 mm.

Next, these are passed through a die to reduce the diameter by about 5 mm, for example, if the outer diameter of the outer tube is 60 mm. This brings the outer tube 18 into close contact with the fin tube 17.

Then, the inner tube 16 is inserted inside the fin tube 17, and its dimensions are adjusted so that there is a gap of about 1 to 2 mm between the outer diameter of the inner tube 16 and the inner diameter of the fin plate 21. Select.

Thereafter, with the inner tube 16 inserted, it is again passed through a die and subjected to cold drawing to reduce the diameter of the entire tube by about 5 mm. As a result, the fin plate 21 comes into contact with the inner tube 16 in a compressed state, so that the contact between the fin plate 21 and the inner tube 16 is improved, and thermal conductivity is improved.

Next, the end structure of the heat exchanger 15 will be explained with reference to FIG. It is attached to the outer tube 18 by welding at a portion 25, and one end of a reducer 26 made of copper or copper alloy is attached to the other end 25 and welded.

A ring 27 is attached to the other end of the reducer 26, and the inner tube 16 is passed through the ring 27. This ring 27 is
It consists of a titanium-copper clad with a titanium tube 28 on the inside and a copper tube 29 on the outside, and the copper is completely removed from the part 30 that is welded to the titanium inner tube 16 on the inside, and the titanium and copper are welded together. It is now possible to make a completely sealed connection.

When using this heat exchanger 15, the inner tube 1
Pass seawater etc. into the inside of the tube 6, and inject a refrigerant (e.g. Freon gas) from the T-joint 23 into the outer fin tube 17.
flow. In this case, since the surface area of the fin plate 21 with the unevenness is increased, the heat transfer efficiency is improved, and the fin plate 21 and the provided unevenness are formed parallel to the traveling direction of the refrigerant. Therefore, fluid resistance can be reduced.

In addition, copper (or copper alloy) and titanium are welded together via a titanium-copper clad ring at the end, making it possible to completely seal the entire product and provide a long service life.

In the above manufacturing method, the diameter of the Finned tube was first put into the outer tube and then the inner tube was put into the reduced diameter Finned tube to further reduce the diameter. It is also possible to manufacture a heat exchanger by reducing the diameter and then inserting the reduced diameter fin tube into the outer tube and further reducing the diameter.

〔Effect of the invention〕

As is clear from the above description, in the heat exchanger according to claim 1, unevenness is formed on the fin plate disposed on the outside of the inner tube, and the fin plate is in contact with the inner tube in a pressed state. Therefore, heat exchange efficiency is improved.

In addition, since the fin tube on which the fin plate is installed is made of aluminum, extrusion molding is easy, and even for large-diameter heat exchangers, sufficient fin plate and length can be secured. Moreover, it can be manufactured by providing irregularities on its surface.

Since the outer tube made of a metal with good corrosion resistance and weldability is closely placed on the outside of the fin tube made of aluminum, it is possible to protect the inner fin tube made of aluminum, and also protect the edges of the fin tube. Joints can be easily welded to the parts.

In the heat exchanger according to claim 2,
The outer tube is made of copper and the joints at the ends are made of copper, and the inner tube is made of titanium using a titanium-copper clad in the middle. Since a seal can be formed, manufacturing becomes inexpensive and furthermore, it becomes possible to perform a complete seal.

In addition, in the method for manufacturing a heat exchanger according to claims 3 and 4, since the fin tubes are made of aluminum, fin tubes having long fin plates can be easily manufactured, and furthermore, they can be combined. By passing it through the die, the pressing force of the fin plate attached to the inner tube increases, improving heat transfer efficiency, and the pressing force of the reduced diameter outer tube is transmitted to the fin tube, even when the fin tube is thin. Even if the fin plate is pressed against the titanium inner tube by the pressing force of the outer tube, the fin plate can be reliably pressed against the titanium inner tube.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main parts of a heat exchanger according to an embodiment of the present invention, FIG. 2 is a plan view of the heat exchanger, FIG. 3 is a side view of the heat exchanger, and FIG. FIG. 5 is a flowchart showing the manufacturing process of the heat exchanger, and FIG. 6 is a sectional view of the main parts of a conventional heat exchanger. [Explanation of symbols], 15... Heat exchanger, 16...
Inner tube, 17...fin tube, 18...outer tube, 21...
... Fin plate, 22 ... Support pipe, 23 ... T-joint,
24...One end, 25...Other end, 26...Reducer, 27...Ring, 28...Titanium tube, 29
...Copper pipe, 30...parts.

Claims (1)

[Claims] 1. An inner tube made of titanium having an inlet portion and an outlet portion;
An aluminum fin tube with a radial cross-sectional inward protrusion of a large number of fin plates whose tips abut on the outside of the titanium inner tube, and an aluminum fin tube with a radially inwardly protruding cross section, and an aluminum fin tube that is arranged in close contact with the outside of the fin tube and at both ends thereof. The fin plate has an outer tube made of a metal with good corrosion resistance and weldability, and is provided with an inlet and an outlet for the refrigerant, and the fin plate has an uneven surface and is compressed in the radial direction so that the inner tube is compressed in the radial direction. A heat exchanger characterized by being pressed against a tube. 2 The outer tube is a copper tube, and a copper joint is connected to both ends of the outer tube, and a titanium-copper cladding is used in the middle to seal the joint and the inner tube made of titanium, and the whole is welded. 2. The heat exchanger according to claim 1, wherein the heat exchanger is closely joined at . 3 Prepare in advance a titanium inner tube of a predetermined diameter, an aluminum fin tube with radial fin plates formed inside, and a copper or copper alloy outer tube, and first insert the fin tube inside the outer tube. The diameter is reduced by passing it through a die.
Next, the inner tube is inserted into the diameter-reduced fin tube with a gap in between, and the entire tube is passed through a die to further reduce the diameter, and then, prescribed joints are joined to both ends. A method for manufacturing a heat exchanger characterized by: 4. Prepare in advance a titanium inner tube with a predetermined diameter, an aluminum fin tube with radially formed fin plates inside, and a copper or copper alloy outer tube, and first insert the inner tube into the fin tube and die. The diameter of the fin plate is reduced through a die, and the fin plate is pressed against the inner tube.Then, the reduced diameter fin tube is inserted into the outer tube, and the outer tube is pressed against the fin tube through a die. A method for manufacturing a heat exchanger, which comprises joining a joint to a heat exchanger.