JPS58158499A - Heat exchanger - Google Patents

Abstract

PURPOSE:To enable to obtain a large heat-exchanging quantity with a compact construction, by a method wherein a heat exchanger used for a Stirling engine or the like is constituted of an outer pipe and an inner pipe which is provided with a plurality of small ejceting holes. CONSTITUTION:In the Stirling engine, an expanding space 7 between a displacer piston 4 and a cylinder head 2 is communicated to a compressing space 8 between a power piston 5 and the piston 4 through the heat exchanger 10 in which a heater 11 for heating a working gas by the heat supplied from a burner 1, a heat regenerator 12 and a cooler 13 are provided in series with each other. The heater 11 has a construction in which the inner pipe 16 provided with a plurality of longitudinal grooves 14 at the surface thereof and a plurality of small ejecting holes 15 at bottom parts of the grooves 14 is inserted in the outer pipe 18 having one end stopped up by a plug 19 so that the two fluid passages formed in a counercurrent manner by the pipes 16, 18 are communicated to each other through the holes 15. In addition, the outer pipe 8 is provided with a plurality of fins 17 on the outside surface thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a compact heat exchanger with a high heat exchange capacity, which is particularly useful for incorporation into a heat engine.

To explain the Stirling engine shown in FIG. 1 as an example of a heat engine, a display is slidably inserted into an upper cylinder 3a of the upper and lower cylinders that constitute the cylinder head 2 and cylinder 3 heated by the burner heat source 1. The space 7 is an expansion space between the top of the service ton 4,
The space 8 between the power piston 5 which is slidably inserted into the lower cylinder 3b and the display service ton 4 is called a compression space, and the space 9 behind the power piston 5 is called a back pressure space, and this expansion space 7 The compressed space 8 is a heater 11 that directly receives heat from the burner heat source 1 disposed outside the cylinder 3 and transmits the heat to the working gas sealed inside the engine.
, a heat regenerator 12 that receives and gives heat during the reciprocation of the working gas, and a cooler 13 that removes heat from the working gas, which are connected by a heat exchanger 10 that is successively configured. The working gas reciprocates according to the so-called Stirling cycle as described below, and heat is exchanged in the heat exchanger 10.

■ Isothermal expansion 111x (see Figure 5 (a)) The working gas in the expansion space 7 and the heater 11 is heated to about 600°C by the burner heat source 1, and the gas pressure at that time is , passes through the cooler 13 and is applied to f[18 during compression, so the power piston 5 is pushed down, and at the same time, for example, a hemi-rhombic mechanism 6. In conjunction with this, the display service ton 4 is also lowered to perform equal collapsing and expansion of the working gas.

■ Equal volume heat dissipation (see Fig. 5 (b)) When the power piston 5 descends to the state shown in Fig. 5 (b) due to inertia force, by raising the display service ton 4 in the opposite direction, the inside of the expansion space 7 is Heater 1 for working gas
1, compression space 8 through heat regenerator 12 and cooler 13
At this time, the working gas heated to approximately 600° C. gives its heat to the heat regenerator 12, and its temperature drops to approximately 200° C., and is further cooled by the cooler 13.

■ Isothermal compression (see Figure 5 (c)) When the pressure in the back pressure space 9 exceeds the pressure in the expansion space 7 and compression space 8, the power piston 5 moves to bottom dead center due to the differential pressure and inertia force. After the display service ton 4, which continues to rise in conjunction with the single rhombic mechanism 6, reaches the state shown in FIG. 5(c), compression of the low-temperature working gas in the compression space 8 begins.

Upper back of power piston 5 and display service ton 4
, the low-temperature working gas in the compression space 8 moves to the expansion space 7 via the cooler 13, the heat regenerator 12, and the heater 11. At this time, the heat accumulated in the heat regenerator 12 in the above-mentioned isovolumic heat dissipation process is absorbed to raise the temperature to about 600°C.

Since the heat exchanger 10 has limited installation locations,
It goes without saying that something that is small and compact and has a large amount of heat exchange is better.

Therefore, the present invention has been made for the purpose of providing a heat exchanger that is extremely suitable for such uses.

The structure of the present invention that achieves the above object is to insert an inner tube with a large number of small ejection holes into an outer tube with one end closed, and to connect the two fluid passages formed by the outer tube and the inner tube to the outer tube. It is connected by a large number of small nozzles.

A preferred embodiment of the present invention will be described in detail below with reference to FIG. 2, in which parts corresponding to those in FIG. 1 are given the same reference numerals. First, regarding the heater 11, a plurality of vertical grooves 14 and vertical grooves 1 are formed on the surface of the outer tube 18 whose one end is closed with a plug 19.
A large number of small ejection holes 15 are drilled at the bottom of 4 (see Figure 3).
The inner tube 16 is inserted, and the two countercurrent fluid passages formed by the two tubes 16 and 18 are communicated through the large number of small jet holes 15 described above.

There are fins 17 on the outside of the outer tube 18 to increase the heat receiving area from the burner heat source 1, and the outer tube 18 is attached to the flange of the cylinder head 2. Internal information 16 attached to the flange of the upper cylinder 3a
Since the tubes 16 and 18 are heated from the outer tube 18 side by thermal conduction, it is preferable that both tubes 16 and 18 are in close contact with each other except for the II groove 14 (outer fluid passage) communicating with the expansion space 7 at its lower end. However, in terms of processing accuracy, even if there is a loose fit of about 10 μI, there is no particular problem.

The inner fluid passage is preferably formed as follows.

That is, by integrally forming the tapered portion 20 on the plug 19 and filling the unnecessary dead space inside the inner tube 16 with the tapered portion 20, an annular inner fluid passage which becomes larger as it goes downward is formed. When determining the formation of the tapered portion 20, setting the annular inner passage cross-sectional area at a certain position to be approximately equal to the total area of the ejection hole 15 up to that position will reduce energy loss due to changes in cross-sectional area. can do. At the same time, the lower end of the tapered portion 20 presses down a wire mesh 21 surrounding a filler 22 of a heat regenerator 12, which will be described later, to prevent it from digging into the heater 11 side.

Next, regarding the heat regenerator 12, the upper end is connected to an inner tube 16, and the lower end is connected to a tube body 30, which will be described later.A tube 23 is filled with a tube that stores heat in an isovolumic heat radiation process and releases the stored heat during an isovolumic heat absorption process. The filler material 22 is loaded, and 24 in the figure is the filler material 2.
It is a wire mesh surrounding 2. If the material for the filler 22 is simply selected from materials with high thermal conductivity, even if the heat is stored, the heat will be easily transferred to the cooler 13, making it impossible to use the heat effectively. A material that is easy to heat, such as a steel ball, and a material that is difficult to heat, such as a ceramic ball, are mixed to form the heater 11.
It is preferable that the composition closer to the cooler 13 is relatively rich in steel balls, and the one closer to the cooler 13 is relatively rich in ceramic balls. By doing so, a sufficient thermal gradient can be obtained between both ends.

In addition, the shape and size of the filler 22 are determined by changing the heat transfer area necessary for rapid heat exchange (to perform heat exchange), passage resistance, or passage cross-sectional area from the heater 11 or cooler 13 as the working gas flows. For example, the shape can be determined from the viewpoint of making the space smaller, such as a rice ball shape, a rice grain shape, or a string of bead shapes.The tube 23 is formed in an S-shape as shown in Fig. 4, and the direction of its bending is determined. If it is attached toward the plane of the paper in FIG. 2, thermal stress caused by the difference in temperature distribution with the upper cylinder 3a can be alleviated.

Finally, the cooler 13 is similar to the heater 11, with one end closed and the other end connected to the cooling water outlet 29 in an outer tube 28 with many small jet holes 27 and a cooling water inlet 25. Since the inner tube 26 that connects with the outer tube 28 is inserted, the outer tube 28
Two counter-current or co-current fluid passages formed by the inner tube 26 and the inner tube 26 are communicated through a jet hole 27. The tube body 30 is connected to the compression space 8 at the lower end and to the tube 23 at the upper end, and forms a passage for the working gas between the tube body 30 and the outer tube 28.
The outside of the tank is cooled by cooling water inside the water jacket 32. Numeral 31 is a nut for fixing the inner tube 26.

Since the present invention has the above-described configuration, for example, when the working gas flows from the compression space 8 to the expansion space 7, the gas jet from the jet hole 15 collides with the inner wall of the outer tube 18, resulting in a turbulent flow. Since the cooling water jet from the jet hole 27 collides with the inner wall of the outer side 28 and becomes a turbulent flow, the working gas and the cooling water are stirred, and the stirring effect quickly achieves extremely high efficiency heat exchange. It is extremely superior in that it can be used as an inexpensive heat exchanger.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a Stirling engine equipped with the heat exchanger of the present invention, Fig. 2 is an enlarged sectional view showing its main parts, and Fig. 3 is a cross-sectional view of the heater inner tube shown in Fig. 2. Figure 4 is a longitudinal sectional view of the tube of the heat regenerator in Figure 2, and Figures 5 (a) to (d) are diagrams for explaining the Stirling cycle. 15.27...Blowout hole, 16.26...Inner pipe, 18
．． 28...Outer tube. Patent Applicant - Naoji Iro Same as Sanyo Electric Co., Ltd. Agent of Tokyo Sanyo Electric Co., Ltd.
Tanema Shigemi
Tomonosuke ArakiContinued from page 1 ■Applicant: Tokyo Sanyo Electric Co., Ltd. 180 Sakata, Oizumi-cho, Iraku-gun, Gunma Prefecture

Claims (1)

[Claims] 1. An inner tube with a large number of small nozzle holes is inserted into an outer tube with one end closed, and the two fluid passages formed by the outer tube and the inner tube are communicated through the large number of small nozzle holes described above. A heat exchanger characterized by: