JPS61223255A - High temperature heat exchanger for stirling engine - Google Patents

Abstract

PURPOSE:To increase transmission of heat to the tube by sewing a radiation metal wire into a heater tube while regulating the winding density in accordance to the temperature distribution. CONSTITUTION:When applying onto a double acting Stirling engine, the cylinder 14 and a thermal accumulator 9 surrounded from above with a combustion wall 15 made of thermal insulator are coupled through a tube 17 constituting a high temperature heat exchanger rising along the sidewall of the combustion wall 15. Then a radiation wire 22 is sewed into the tube 17 to secure the joint between the tube 17 and the wire 22 through brazing. The working medium is flowed in the tube 17. The number of wires 22 per unit area is increased at the low temperature section or the lower section.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a high-temperature heat exchanger used in a Stirling engine, and relates to improving the heat exchange efficiency thereof.

[Conventional technology]

Figure 4 is a cross-sectional view showing a double-acting Stirling engine, and Figure 5 is a cross-sectional view showing a high-temperature heat exchanger applied to a conventional double-acting Stirling engine, as disclosed in, for example, Japanese Patent Laid-Open No. 59-34859. Yes, 4th
In the figure, 1.2, 3° and 4 are cylinders, each of which is provided with a displacer piston 5 that reciprocates within the cylinder.The upper part of each displacer piston 5 is an expansion space 6. , the compression space 7 is located below. The displacer pistons 5 of the cylinders 1 to 4 are arranged with a phase difference of 90'' from each other.The expansion space 6 of the cylinder 1 and the compression space 7 of the cylinder 2 are connected, and in the communication path, the A hot heat exchanger 8, a heat storage device 9, and a low temperature heat exchanger 10 are sequentially formed from the expansion space 6 toward the compression space 7.

The high temperature heat exchanger 8 heats the working fluid,
The heat storage device 9 stores the heat of the working fluid before being cooled, and the low-temperature heat exchanger 10 cools the working fluid. The high temperature heat exchanger 8 and heat storage device 9. And the low-temperature heat exchanger 10 is provided between the cylinders 2 and 3, between the cylinders 3 and 4, and between the cylinders 4 and the cylinders.
A total of four sets are provided, and the four cylinders 1 to 4 are related to each other. Note that the rod 11 of each displacer piston 5 is slidably attached to the swash plate 12, so that the output shaft 13 is rotated by these rods 11.

FIG. 5 is a detailed view of the high temperature heat exchanger 8. In the figure,
Reference numeral 14 denotes a cylinder, and a combustion wall 15 made of a heat insulating material is provided so as to cover the upper side of the cylinder 4. A large number of tubes 17 are arranged within a combustion space 16 of this combustion wall 15. The tube 17 rises upward to form a cylindrical shape along the side wall of the combustion wall 15, forming a high-temperature heat exchanger, through which a working medium flows.

A nozzle 18 is provided centrally above the combustion wall 15 and is configured to cooperate with a swirler 19 to create a combustion flame. The high temperature gas in the space 16 moves to the outside of the pipe 17 through the gap h (see -) of the tube 17, and is exhausted through the air preheater 20 provided as required. Furthermore, a radiation plate 21 made of a metal plate, ceramics, or the like is provided within the gap of the tube 17.

This radiation plate 21 is arranged approximately in the middle of the gap and is made of a thin plate extending in the vertical direction.

Next, the operation will be explained. In the above-mentioned Stirling engine, the high temperature heat exchanger 8 is made up of a large number of chains and tubes 17, and the working fluid in the tubes 17 is heated by contact with the high temperature combustion gas. Further, when the combustion gas flows through the gap, the radiant plate 21 is also heated at the same time as the tube 17, and the radiant plate 21 radiates radiant heat to the tube 17 disposed oppositely, thereby further heating the tube 17.

At this time, the radiant plate 21 becomes hotter than the tube 17, so the amount of radiant heat becomes large.

[Problem that the invention seeks to solve]

Although the conventional high-temperature heat exchanger is configured as described above, it is difficult to fix the radiation plate 21 between the tubes 17, and it is difficult to correct the longitudinal temperature distribution of the tube 17 as a heater tube. There were problems such as not being able to do so.

This invention was made to solve the above-mentioned problems, and is a high-temperature heat exchanger for a Stirling engine that can increase the amount of heat transferred to the tube, which is a high-temperature heat exchanger, and correct the temperature distribution of the heater tube. The purpose is to obtain equipment.

[Means for solving problems]

In the high-temperature heat exchanger for a Stirling engine according to the present invention, a metal wire body for radiation is wound around a group of heater tubes in a net shape, and the density of the winding of the metal wire body is changed depending on the temperature distribution of the heater tubes. It is something.

[Effect]

In this invention, the amount of heat transferred to the tube is increased by radiation heat transfer and heat conduction of the metal wire body wrapped around the heater tube group, the temperature distribution of the heater tube is improved, and manufacturing is easy. Since the amount of tubes can be reduced accordingly, the cost and weight can be reduced, and the layout of the space above the cylinder can be simplified.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 14 is a cylinder, 15 is a combustion wall made of a heat insulating material provided to cover the upper part of the cylinder 14, and 16 is a combustion wall.
is a combustion space inside the combustion wall 15; 17 is a tube connected to the cylinder 14 and the heat storage device 9;
rises upward along the side wall of the combustion chamber 15- to form the cylinder 1.
This constitutes a high-temperature heat exchanger. Further, a working medium flows inside the tube 17. combustion wall 1
A nozzle 18 is provided at the upper center of 5, and the nozzle 18
A combustion flame is formed by the swirler 19 and the swirler 19. 22 is a wire provided so as to thread between the tubes 17.

FIG. 2 shows an embodiment in which the present invention is applied to an Annieler type high-temperature heat exchanger. However, combustion wall 15° combustion space 16
．． Nozzle 18. The swirler 19 is omitted in this figure.

Here, the wire 22 is arranged as follows. That is, the temperature distribution of the tube 17 is measured in advance in a state where no wires 22 are disposed, and in areas where the temperature is low, a large number of wires 22 per unit area are disposed.

However, the temperature distribution of the heater pipe tube 17 varies depending on the characteristics of the burner, so it is a prerequisite that the same burner is used.Then, the wire 22 is threaded around the tube 17, and wire 2
Fix the contact point 2 by brazing or the like. At this time, at the contact point, there is 0 between the wire 22 and the tube 17.
It is important to avoid creating air spaces.

Next, the effects will be explained. In the high-temperature heat exchanger (Annular type) of the Stirling engine shown in Fig. 2, the temperature distribution of the tube 17 when there is no wire 22 is shown in Fig. 3 (Fig. 3). I understand that there is something. Figure (a) shows the measurement points. Therefore, in this embodiment, the wire 22 is installed between the tubes 17 in a weaving manner, thereby calibrating the temperature distribution and increasing the amount of heat transfer. Ru. The actual heat transfer mechanism involves heating the working fluid in the tubes 17 by bringing high-temperature gas into contact with a large number of tubes 17.
Furthermore, as the combustion gases flow through the tube gap, they heat both tube 17 and wire 22. Therefore wire 2
2 radiates radiant heat to the tube 17 disposed opposite to it, and at the same time heat is transferred to the tube 17 by thermal conduction, making the tube 17 even more heated. By arranging the wires 22 more closely in the lower part of the tube 17 than in the middle part, the amount of heat transferred to the tube 17 can be adjusted and the temperature distribution of the tube 17 can be adjusted. Adjust the imbalance.

In addition, in the above embodiment, wires were arranged, but
This may be a tape-shaped metal, and the same effect as in the above embodiment can be achieved.

Further, as for the material of the wire, any material may be used as long as it is a heat-resistant material and has high plasticity.

〔Effect of the invention〕

As described above, according to the present invention, a metal linear body for radiation such as a wire is wound around the heater tube in a stitched manner, and the density of the wrapping is adjusted by the temperature i cloth. This has the effect of increasing the amount of heat transferred to the tube and making the temperature distribution of the heater tube uniform.

[Brief explanation of drawings]

FIG. 1(a) is a cross-sectional view of a high-temperature heat exchanger showing an embodiment of the present invention applied to a double-acting Stirling engine, FIG. Figure (a) is a sectional view showing an example of an actual kM when this invention is applied to an anierer type high temperature heat exchanger for a displacer type Stirling engine, and Figure 2) is a cross-sectional view of the nb-
NB cross-sectional view, FIG. 2(C) is a partially enlarged view, FIG. 3(a) is a schematic diagram for explaining a double-acting Stirling engine using a heater tube exchanger, and FIG. FIG. 5(a) is a cross-sectional view showing a conventional high-temperature heat exchanger, and FIG. 5(b) is a cross-sectional view taken along the line vb-vb. 17... Heater tube, 22... Wire. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (3)

[Claims] (1) In the high temperature heat exchanger of the Stirling engine,
1. A high-temperature heat exchanger for a Stirling engine, characterized in that it is provided with a metal linear body for radiation that is threaded around a heater tube and makes the temperature distribution of the heater tube uniform. (2) The high-temperature heat exchanger for a Stirling engine according to claim 1, wherein the metal linear body for radiation is a wire. (3) The high-temperature heat exchanger for a Stirling engine according to claim 1, wherein the metal wire body for radiation is a tape-shaped metal body.