JPH07294163A - Heat exchanger - Google Patents

Abstract

PURPOSE:To increase a heat exchanging efficiency under a less number of component parts by a method wherein there are provided porous material filled in a first pipe passage through which fluid W flows, and fins set an outer circumferential surface of the first pipe passage in a second pipe passage arranged so as to outwardly enclose the first pipe passage in which second fluid to perform a heat exchanging operation through the pipe wall. CONSTITUTION:In a heat exchanger of an external combustion engine using a Starling cycle or a Vuilleumier cycle, gas is contacted with a porous sintered member 6 at its quite wide area when the gas passes through the porous sintered member 6 within inner pipes 2, so that heat is easily removed by the porous sintered member 6. Although heat transmitted to the porous sintered member 6 is radiated outside each of the inner pipes 2 and also inside an outer pipe 3, the heat is also radiated through each of helical fins 7. There are provided a plurality of inner pipes 2 and each of the inner pipes 2 is provided with some helical fins 7 to cause a contact area with cooling water flowing between each of the inner pipes 2 and the outer pipe 3 to become wide and then heat radiation can be easily carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger, and more particularly to a heat exchanger applied to an external combustion engine using a Stirling cycle or a Wilmier cycle.

[0002]

2. Description of the Related Art Conventionally, shell-type heat exchangers for external combustion engines that use the Stirling cycle and the Wilmier cycle
Some use the and-tube method. The shell-and-tube type has a large number of small-diameter pipes arranged in parallel in a large-diameter pipe, gas is passed through the small-diameter pipe, and cooling water is caused to flow outside the small-diameter pipe. The heat is exchanged.

In the heat exchanger having the above structure, by reducing the diameter of the small-diameter pipes and increasing the number of the pipes, the specific surface area of the two fluids in contact with each other via the pipe wall becomes large, so that the heat exchange efficiency is improved. Can be increased. However, in the heat exchanger of the above method, not only is the manufacturing process complicated due to the large number of component parts, but since there are many brazing points due to the use of a large number of pipes, if gas leaks from the brazing part, There is a problem that the reprocessing may become difficult and the manufacturing cost may increase.

[0004]

SUMMARY OF THE INVENTION In view of the above problems of the prior art, a main object of the present invention is to provide a heat exchanger capable of enhancing heat exchange efficiency with a small number of parts.

[0005]

According to the present invention, it is an object of the present invention to provide a first conduit for passing a first fluid and the first wall through a wall of the first conduit. A second conduit provided so as to surround the first conduit for passing a second fluid that exchanges heat with a first fluid, the heat exchanger comprising: A porous body filled in the first conduit, and a fin-shaped body provided in the outer peripheral surface of the pipe wall of the first conduit in the second conduit. This is achieved by providing a heat exchanger that In particular, the fins consist of radially outward facing flange-shaped fins, or the first fluid is arranged to spirally flow the second fluid around the tube wall of the first conduit. It is preferable that the outer peripheral surface of the pipe wall of the pipe is formed in a spiral shape. Alternatively, the first fluid passage for passing the first fluid and the second fluid for exchanging heat between the first fluid through the tube wall of the first fluid passage may be passed. A heat exchanger having a second conduit provided so as to surround the first conduit,
A porous body filled in the first pipeline, and a cylindrical porous body provided in the second pipeline and on the outer peripheral surface of the pipe wall of the first pipeline. A heat exchanger characterized by having.

[0006]

According to this structure, since the first fluid passes through the porous body when passing through the first conduit, the gas and the porous body are contacted with the porous body having a large contact area. Heat exchange with the body is facilitated. The heat transmitted to the porous body is conducted to the tube wall of the first pipeline, and through the fin-shaped body or the porous body provided on the outer peripheral surface thereof, a large contact area with the second fluid is obtained. The heat is radiated into the second conduit while ensuring the heat dissipation.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a vertical cross-sectional view of a heat exchanger 1 of an external combustion engine using a Stirling cycle or a Vilmier cycle to which the present invention is applied, and FIG. 2 is a main part viewed from an arrow II line in FIG. FIG. As shown in FIGS. 1 and 2, the present heat exchanger 1 is provided with a plurality of inner pipes 2 (five in the figure) that form a first pipe line in parallel with each other, and the pipe walls of the inner pipes 2 are arranged. And an outer pipe 3 which collectively surrounds the inner pipes 2 so as to form a second conduit on the outer side. The axial lengths of the pipes 2 and 3 are the same.

On both end faces of the outer pipe 3 in the axial direction,
Plate-shaped lid bodies 4 formed so as to be closed except for the inner pipes 2 are fixed. Further, the cooling water inlet pipe 5a is provided at the upper end portion of the pipe wall of the outer pipe 3 in FIG.
The cooling water outlet pipe 5b is fixed to the lower end portion of the pipe wall of the outer pipe 3 in FIG.

A cylindrical porous sintered body 6 as a porous body is inserted into the inner pipe 2 and fixed in a filled state. The porous sintered body 6 may be formed by solidifying core materials such as cutting powder or powder of metal such as copper integrally bonded by diffusion bonding or brazing. It is also possible to use a material in which a wire material such as SUS or copper is woven and then press-solidified. Further, the material is not limited to metal and may be ceramics, for example. Then, on the outer peripheral surface of the tube wall of the inner pipe 2, a spiral fin 7 is provided as a fin-shaped body that is spirally wound and fixed. In addition, when the spiral water is formed so as to be wound in a direction that promotes the flow of the cooling water, the cooling water can smoothly flow without staying.

In the heat exchanger 1 thus constructed, the gas as the first fluid flowing from the high temperature chamber side (not shown) flows through the inside pipes 2 from above in FIG. It is designed to pass through downward. Cooling water as a second fluid that exchanges heat with the gas flows in from the cooling water inlet pipe 5a between the inner pipe 2 and the outer pipe 3 and flows out from the cooling water outlet pipe 5b. .

When the gas passes through the porous sintered body 6,
Since it comes into contact with the porous sintered body 6 in an extremely wide area, the porous sintered body 6 easily removes heat. The heat transmitted to the porous sintered body 6 is radiated to the outside of each inner pipe 2 and the inside of the outer pipe 3 via the tube wall of each inner pipe 2, but in this embodiment, each spiral Heat is also dissipated through the fins 7. By providing a plurality of inner pipes 2 and providing spiral fins 7 on each of them as in the embodiment, the contact area with the cooling water passing between each inner pipe 2 and the outer pipe 3 is wide, and heat dissipation is easy. To be done.

Since the gas is passed through the porous sintered body 6 in this manner, the diameter of the inner pipe 2 corresponding to the small diameter pipe in the shell-and-tube type shown in the conventional example can be increased. Yes, the number of pipes can be reduced, and the temperature difference between the gas inlet and outlet becomes large,
The heat exchange rate could be improved. Further, by providing the spiral fins 7 that form a plurality of fins in the axial direction, the contact area with the cooling water is wide and the heat exchange efficiency can be further improved. In this embodiment, the spiral fins 7 are provided so as to be spirally wound around the outer peripheral surface of each inner pipe 2, but the fins provided on the outer peripheral surface of the inner pipe 2 are not limited to the illustrated spiral ones. Alternatively, a plurality of outward flange-shaped fins may be arranged side by side in the axial direction at intervals. Further, the number of the inner pipes 2 is not limited to five as shown in the figure, and may be one or any number of two or more.

FIG. 3 is a view corresponding to FIG. 1 showing a second embodiment, and FIG. 4 is a fragmentary sectional view taken along the line IV in FIG. 3, showing a portion similar to the above embodiment. Are denoted by the same reference numerals, and detailed description thereof will be omitted. In this second embodiment, instead of the spiral fin 7 of the previous embodiment,
A cylindrical porous sintered body 8 is fixed to the outer peripheral surface of each inner pipe 2. This porous sintered body 8 may also be made of the same material as the porous sintered body 6 of the above embodiment.

In the second embodiment, the flow directions of the gas and the cooling water are the same as those in the above embodiments, but part of the cooling water passes through the porous sintered body 8. Therefore, the heat radiated from the tube wall of the inner pipe 2 is radiated through the porous sintered body 8, so that the contact area with the cooling water is widened and, in addition to the heat exchange effect similar to that of the above-described embodiment, There is an effect that the heat dissipation portion can be made small. The number of the inner pipes 2 in the second embodiment may be the same as that in the above embodiment.

FIG. 5 is a view corresponding to FIG. 1 showing a third embodiment, and FIG. 6 is a fragmentary sectional view taken along the line VI in FIG. 5, showing a portion similar to the above embodiment. Are denoted by the same reference numerals, and detailed description thereof will be omitted. In the third embodiment, only one inner pipe 9 is provided inside the outer pipe 3. A spiral fin 10 is provided on the outer peripheral surface of the pipe wall of the inner pipe 9. The spiral fin 10 extends outward in the radial direction from the outer peripheral surface of the inner pipe 2 to the inner peripheral surface of the outer pipe 3, and cools from the vicinity of the cooling water inlet pipe 5 a while rotating around the outer periphery of the inner pipe 9. A spiral flow path reaching the vicinity of the water outlet pipe 5b is formed. The spiral winding direction is the direction in which the cooling water flows from the cooling water inlet pipe 5a toward the cooling water outlet pipe 5b.

The flow direction of gas and cooling water in this third embodiment is the same as that in the previous embodiment, but the spiral fin 1 is used.
When 0, the cooling water flows spirally around the inner pipe 9, and the cooling water can efficiently flow so that the contact time with the wall of the inner pipe 9 and the spiral fin 10 becomes long. Therefore, in addition to the heat exchange effect similar to that of the first embodiment, the portion that does not contribute to the heat exchange of the cooling water can be reduced.

[0018]

As described above, according to the present invention, the first fluid is allowed to pass through the porous body having a large contact area to cause heat exchange between the gas and the porous body, and the first conduit Since a fin-shaped body or a porous body is provided on the outer peripheral surface of the pipe wall to perform heat exchange with the second fluid, a large contact area with the second fluid can be secured and heat exchange efficiency can be improved. . In addition, compared to the conventional shell-and-tube type, heat exchange efficiency can be improved without the need for a large number of small-diameter pipes, so not only can the number of constituent parts be reduced, but leakage at brazing points The inspection can be simplified, the manufacturing process can be simplified, and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a heat exchanger of an external combustion engine to which the present invention is applied.

FIG. 2 is a fragmentary sectional view taken along the line II in FIG.

FIG. 3 is a view similar to FIG. 1 showing a second embodiment.

FIG. 4 is a fragmentary sectional view taken along the line IV in FIG.

FIG. 5 is a view similar to FIG. 1 showing a third embodiment.

6 is a fragmentary sectional view taken along the line VI in FIG.

[Explanation of symbols]

 1 Heat Exchanger 2 Inner Pipe 3 Outer Pipe 4 Lid 5a Cooling Water Inlet Pipe 5b Cooling Water Outlet Pipe 6 Porous Sintered Body 7 Annular Fin 8 Porous Sintered Body 9 Inner Pipe 10 Spiral Fin

Claims (4)

[Claims] 1. A first conduit for passing a first fluid;
A second pipe provided so as to surround the first pipe line so as to pass a second fluid that exchanges heat with the first fluid via the pipe wall of the first pipe line. A heat exchanger having a pipe line, wherein a porous body filled in the first pipe line and an outer peripheral surface of a pipe wall of the first pipe line in the second pipe line. And a fin-shaped body provided on the heat exchanger. 2. The heat exchanger according to claim 1, wherein the fin-shaped body is formed of an outward flange-shaped fin that is outward in the radial direction. 3. The fin-shaped body has a spiral shape on the outer peripheral surface of the pipe wall of the first conduit so that the second fluid flows in a spiral shape around the pipe wall of the first conduit. The heat exchanger according to claim 1, wherein the heat exchanger is formed in 4. A first conduit for passing a first fluid,
A second pipe provided so as to surround the first pipe line so as to pass a second fluid that exchanges heat with the first fluid via the pipe wall of the first pipe line. A heat exchanger having a pipe line, wherein a porous body filled in the first pipe line and an outer peripheral surface of a pipe wall of the first pipe line in the second pipe line. And a cylindrical porous body provided in the heat exchanger.