JPS60207898A - Heat exchanger - Google Patents

Abstract

PURPOSE:To make easy manufacture and contrive to improve the relative position accuracy between a heat medium flowing pipe and dummy bars, by a method wherein dummy bars are composed with a plural of divided bodies which are arranged in an axial direction and flexible connecting elements which connect said divided bodies. CONSTITUTION:A pipe 31 is shaped flexibly beforehand with a single body. A dummy bar 33 is inserted inside of a pipe 32, after said pipe is secured to a flange part, etc. Positioning members 37 are secured beforehand in the inner surface of the pipe 32 or at the outside surface of the dummy bar 33. When the dummy bar 33 approaches the bent part of the pipe 32, a connecting wire 36 which connects divided body 34 deforms and the whole dummy bar 33 advances along the inside surface of the pipe 32. Since positioning elements are secured in the inside surface of the pipe 32 or at the outside surface of the dummy bar 33, the dummy bar 33 can be arranged coaxially in the pipe 32.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a heat exchanger used, for example, in a Stirling engine, and particularly to a heat exchanger with excellent assembly performance.

[Technical background of the invention and its problems]

The Stirling engine is a hot gas reciprocating engine that drives pistons in expansion and compression cylinders by thermal expansion and contraction of a working fluid.

FIG. 1 is a diagram showing a schematic configuration of such a Stirling engine, and numerals 1 and 2 in the figure are an expansion cylinder and a compression cylinder, respectively, which are vertically protruded from the upper part of the crank chamber 3. An expansion piston 4 is housed inside the expansion cylinder 1 so as to be able to freely reciprocate, and a compression piston 5 is housed inside the compression cylinder 2 so as to be able to freely move back and forth. Inside the crank chamber 3, a crankshaft 8 whose rotation axis is perpendicular to the reciprocating direction of the pistons 4.5 is accommodated and rotatably supported by bearings 9, 10. Both pistons 4 and 5 are connected to the crankshaft 8 via connecting rods 11 and 12, respectively, so that they reciprocate while maintaining a phase difference of, for example, 90 degrees.

The inside of the expansion cylinder 1 and the inside of the compression cylinder 2 are connected via a working fluid path 13. A heater 14, a regenerator 15, and a cooler 16 are connected in series to this working fluid path 13 in this order from the expansion cylinder 1 side to the compression cylinder 2 side. Heater 14 and cooler 16
Each consists of a heat exchanger with a high temperature source and a low temperature source. He and H2 are inside the working fluid path 13 and each cylinder 1, 2.

It is filled with a working fluid P made of a non-condensable gas such as N2.

In the Stirling engine configured in this way,
When the compression piston 5 is now at the top dead center and the expansion piston 4 is in the downward process, the working fluid P moves through the working fluid path 13 from the compression cylinder 2 to the expansion cylinder 1 in the direction of the solid arrow in the figure. The working fluid P is heated by the heater 14 during this movement process.

When the working fluid P is heated in this way, the working fluid P expands, and this gas pressure moves the expansion piston 4 downward in the figure. At this time, the compression piston 5 begins to descend,
The working fluid P moves through the working fluid path 13 from the expansion cylinder 1 to the compression cylinder 2 in the direction of the dotted line arrow in the figure. During this movement, the working fluid P gives heat to the heat storage agent inside the regenerator 15 and is cooled by the cooler 16 . When the working fluid P is cooled in this way, the working fluid P contracts and causes the compression piston 5 to rise. By this compression stroke, the working fluid P
further compressed. At this time, the expansion piston 4 begins to descend, so the working fluid flows again to the expansion cylinder 1 side, takes away the heat stored in the regenerator 15, and one cycle ends.

In this way, in the Stirling engine, the expansion cylinder 1, the heater 14, the regenerator 15, the cooler 16, and the compression cylinder 2 constitute a closed flow path for the working fluid P. The original space directly involved in this is the stroke volume of the expansion cylinder 1 and the compression cylinder 2, and the other spaces are dead volumes. Therefore, it is desirable that this ineffective volume be as small as possible.

However, if the cross-sectional area of the flow path for the working fluid is made too small in order to reduce this ineffective volume, there is a problem in that the flow resistance of the working fluid increases, eventually leading to a decrease in output.

On the other hand, in this type of hot gas reciprocating engine, the lower the temperature of the working fluid on the low-temperature side and the higher the temperature on the high-temperature side of the working fluid, the higher the engine efficiency increases. Therefore, it is desirable that the heat exchangers constituting the heater 14 and the cooler 16 have high heat exchange efficiency.

Therefore, in order to satisfy these demands, in this type of hot gas engine, the heat exchanger is constructed by arranging a large number of meandering and bent tubular heat exchanger bodies 21 in parallel, as shown in FIG. There is. With this configuration, the heat exchanger main body 2
1 and the heat exchanger body 21.
The second heat flowing through the outer surface of! In IIR, the heat transfer area can be increased.

Each heat exchanger main body 21 is constructed by coaxially inserting a dummy rod 23 whose outer diameter is smaller than the inner diameter of the pipe 22 into a meandering bent pipe 22, as shown in FIG. A working fluid flow path is formed between the inner surface of the vibrator 22 and the dummy rod 23. And vibe 2
A positioning member 24 is interposed between the dummy rod 2 and the dummy rod 23 at a predetermined position in the axial direction so that the flow path having a thin and uniform thickness can always be maintained.

By configuring the heat exchanger main body 21 in this way, it is possible to reduce the ineffective volume without causing a decrease in the heat transfer area, and it is also possible to improve the heat exchange efficiency.

However, such a heat exchanger has the following problems.

That is, since the dummy rod 23 is a rigid body, it is necessary to insert the dummy rod 23 into the inside of the vibrator 22 before bending the pipe 22, as is clear from the above structure. Therefore, the pipe 22 and the dummy rod 23 are bent after the dummy rod 23 is inserted into the vibrator 22. Therefore, the work of aligning the axial center of the dummy rod 23 with the axial center of the vibrator 22 is extremely troublesome, leading to a complicated work process.

In addition, if the axes of the two are extremely misaligned due to this, the uniformity of the flow path will be impaired, resulting in a decrease in heat exchange efficiency, and if the two come into contact, the contact area will be damaged. becomes a concentrated load point and heat point, and excessive thermal stress acts on the pipe 22, resulting in a problem of reduced reliability.

(Object of the Invention) The present invention has been made based on such conventional drawbacks, and its purpose is to reduce the dead volume by inserting a dummy rod inside the heat medium flow pipe. In a heat exchanger designed to improve heat exchange efficiency, it is possible to simplify manufacturing and improve the relative positional accuracy between the heat medium flow pipe and the dummy rod, thereby improving heat exchange efficiency and Our objective is to provide a heat exchanger with excellent reliability.

[Summary of the invention]

In the present invention, a dummy rod is coaxially inserted inside a partially bent heat medium flow pipe, and a heat medium flow path is formed between the inner surface of the heat medium flow pipe and the dummy rod. The heat exchanger is characterized in that the dummy rod is composed of a plurality of divided bodies arranged in the axial direction and a flexible connecting member that connects these divided bodies. It is said that

〔Effect of the invention〕

According to the present invention, since the dummy rod is constituted by a plurality of divided bodies and a flexible connecting member that connects these parts, the degree of freedom in the shape of the dummy rod can be increased. Therefore, it is possible to insert the dummy rod later into the heat medium flow tube which is bent in advance. Therefore, it is possible to improve the productivity of the heat exchanger.

In addition, since the degree of freedom of the dummy rod increases as described above, by providing an appropriate positioning member between the dummy rod and the heat medium flow pipe, the dummy rod can be easily arranged coaxially with the heat medium flow pipe. be able to.

Further, according to the present invention, since the dummy rod can be removed individually after the heat exchanger is assembled, there is also an advantage in terms of maintenance of the heat exchanger.

(Embodiments of the Invention) Hereinafter, embodiments of the present invention will be described based on FIG. 4.

The heat exchanger main body 31 shown in FIG. 4 is one of a plurality of heat exchanger bodies arranged in parallel as shown in FIG. 2, and 32 in the figure is
This is a vibrator that serves as a heat medium flow tube. This vibrator 32 is meanderingly bent so that the heat transfer area of the heat medium can be made as large as possible, and a dummy rod 33 is coaxially arranged inside the vibrator 32 .

This dummy rod 33 includes a plurality of cylindrical divided bodies 34 arranged with slight gaps in the axial direction, and these divided bodies 34.
The divided body 34
It is composed of connecting wires 36 that connect each other. A positioning member 31 is interposed between the vibrator 32 and the dummy rod 33 at a predetermined position in the axial direction in order to accurately arrange the dummy rod 33 coaxially with the vibrator 32. In addition, the divided bodies 3 at both ends of the dummy rod
The tips of 4a and 34b are tapered so that the dummy rod 33 can be easily inserted into the vibrator 32.

With such a configuration, the heat exchanger main body 31 can be assembled as follows.

That is, the vibrator 31 is bent and formed as a single unit in advance. The bent vibrator 31 is fixed to, for example, a flange portion (not shown). After that, the above-mentioned dummy rod 33 is inserted into the inside of the vibrator 32.

The positioning member 37 is fixed in advance to the inner surface of the vibrator 32 or the outer surface of the dummy rod 33. When the dummy rod 33 reaches the bending part of the vibrator 32, the divided body 34 and the divided body 3
4 and the connecting wire 36 is deformed and the dummy rod 33
The entire process follows the inner surface of the vibrator 32.

Since a positioning member 37 is fixed to the inner surface of the vibrator 32 or the outer surface of the dummy rod 33, the dummy rod 33
3 will be placed coaxially within the pipe 32.

In this way, according to this embodiment, the dummy rod 33 can be coaxially inserted into the bent vibrator 32 without any difficulty. Therefore, it is possible to provide a heat exchanger with excellent manufacturability. Moreover, due to the presence of the positioning member 37, the vibrator 32 and the dummy rod 33
Since the axial centers can be precisely aligned with each other, a uniform flow path can be formed. Therefore, the heat exchange efficiency is also extremely good.

Note that the present invention is not limited to the embodiments described above.

For example, if the split body 34 and the connecting wire 36 are connected in a loosely fitted state, when inserting the dummy rod 33 into the inside of the vibrator 32, the connecting wire 36, which serves as a guide, first
may be installed inside the pipe 32, and the divided bodies 34 may be sequentially installed on the connecting wire 3G to form the heat exchanger main body.

Further, the member for connecting the divided bodies is not limited to a wire-like member, but may be, for example, a metallic mesh-like member. In this case, the dummy rod may be configured so that the mesh-like connecting member wraps around the divided body.

Furthermore, it goes without saying that the present invention is not particularly limited to heat exchangers used in Stirling engines, but can also be applied to other aspects, such as gasoline engines, diesel lines, and various power generation plants. Nor.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the general configuration of a Stirling engine, Fig. 2 is a perspective view showing the main parts of a heat exchanger used in the engine, and Fig. 3 is a diagram showing the main body of the heat exchanger in the same engine.
4 is a longitudinal sectional view showing a heat exchanger main body in a heat exchanger according to an embodiment of the present invention. 1... Expansion cylinder, 2... Compression cylinder, 3...
・Crank seedling, 4... Expansion piston, 5... Compression piston, 8... Crankshaft, 9, 1o... Bearing, 1
1.12... Connecting rod, 13... Working fluid path, 14... Heater, 15... Regenerator, 16...
... Cooler, 21.31 ... Heat exchanger body, 22, 3
2...Pipe, 23.33...Dummy rod, 24.3
7... Positioning member, 34... Divided body, 35...
Hole, 36... Connection wire, P... Working fluid, Q, R
...heat medium. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] A dummy rod is coaxially inserted into a partially bent heat medium flow pipe, and a heat medium flow path is formed between the inner surface of the heat medium flow pipe and the dummy rod. In the heat exchanger,
The dummy rod includes a plurality of divided bodies arranged in the axial direction;
A heat exchanger comprising a flexible connecting member that connects these divided bodies.