JPH0587754B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a low-temperature side heat exchanger for a hot gas engine such as a Stirling engine.

[Conventional technology]

FIG. 4 is a cross-sectional view showing a conventional Stirling engine shown in, for example, Japanese Utility Model Application No. 61-55147. In the figure, 1 is a heater tube attached to the regenerator housing 2, and 3 is a stainless steel wire mesh 4 is a cooler which is a low temperature side heat exchanger,
5 is a block into which the cooler 4 is inserted, and 6 is a passage guide member.

Fig. 5 is a detailed sectional view of the low-temperature side heat exchanger, where 7 is a cooling water inlet flange into which water, which is the cooling fluid of the shell and tube heat exchanger, flows in, and 8 is a cooling water inlet flange through which the cooling water flows out. Cold water outlet flange. 9 is a He inlet flange through which He (helium), a heat exchange fluid, flows; 10 is a He inlet flange through which He flows out.
This is the exit flange. 11 is He inlet flange 9
A heat exchange pipe 12 which is disposed between the He outlet flange 10 and the helium outlet flange 10 and whose both ends are brazed to each flange, through which He, which is a heat exchange medium, flows.
13 is the shell of the shell and tube.

Next, the operation will be explained. The fluid (He) heated in the first part of the heater tube flows into the regenerator 3 and is gradually cooled, and its temperature is lowered from 650°C to 80°C.
The fluid then enters the cooler 4 and is cooled, reducing its temperature to 25°C.

Next, the operation of the cooler 4 will be explained in detail. In FIG. 5, high-temperature He (approximately 80°C), which is a heat exchange fluid, enters from the He inlet flange 9.
It flows through the heat exchange pipe 11. Further, water (approximately 10° C.), which is a cooling fluid, enters from the cooling water inlet flange 7 and flows outside the heat exchange pipe 11 to cool He in the heat exchange pipe 11 by heat transfer. He cooled while passing through the heat exchange pipe 11 (approximately 25°C)
flows out from the He outlet flange 10. Also,
Water, which is a cooling fluid, removes heat from He and flows out from the cooling water outlet flange 8. The baffle plate 12 disturbs the flow of cooling water, cools the water whose temperature has risen on the pipe surface by forced convection, and improves heat exchange efficiency.

[Problem that the invention seeks to solve]

Conventional low-temperature side heat exchangers are configured as described above, so that the He gas does not get wet with the cooling water.
The He inlet flange 9, the He outlet flange 10 and the heat exchange pipe 11 must be brazed. However, when this brazing is performed, distortion due to thermal stress generated during brazing and clogging and wetting of heat exchange pipes due to poor brazing occur, and in order to eliminate these problems, complicated processing methods are required. Therefore, the processing cost is also high. Furthermore, although the conventional structure described above requires a large number of pipes, there is a limit to how small the pipe pitch can be made due to constraints during brazing, resulting in problems such as the device being large and heavy.

This invention was made to solve the above-mentioned problems. It eliminates brazing from the manufacturing process, simplifies the processing method, lowers processing costs, and allows for lighter and smaller heat engines. The purpose is to obtain a low temperature side heat exchanger.

[Means for solving problems]

The low-temperature side heat exchanger for a heat engine according to the present invention includes a cylindrical housing, the housing is inserted and fixed into the housing, and a cooling fluid flow path is formed between the outer peripheral wall surface of the housing and the inner wall surface of the housing. A heat exchanger main body having minute grooves along the axial direction in the inner circumferential portion thereof, and fins that increase the contact area with the cooling fluid on the outer circumferential wall surface are formed integrally with the outer circumferential surface,
and a heat exchanger body made of a rod-shaped body made of an aluminum material and having a sealing part at an upper end and a lower end of an outer circumferential part, the sealing part being in close contact with the inner surface of the housing and sealing a region where the cooling fluid flow path is formed; A liner is press-fitted into the inner periphery of the heat exchanger body and uses the grooves as flow paths for the fluid to be cooled.

[Effect]

In this invention, a cylindrical housing;
A heat exchanger body that is inserted and fixed into the housing and forms a flow path for cooling fluid between the outer circumferential wall surface of the heat exchanger body and the inner wall surface of the housing. Fins having grooves and increasing the contact area with the cooling fluid are formed integrally with the outer peripheral wall surface, and are in close contact with the inner surface of the housing at the upper and lower ends of the outer peripheral portion, and fins for increasing the contact area with the cooling fluid. a heat exchanger body made of an aluminum rod-shaped body having a sealing part that seals a region where a flow path is formed;
Since the groove is configured to include a liner that serves as a flow path for the fluid to be cooled, the working fluid flow path and the cooling fluid flow path can be formed without brazing. Since most of the heat exchanger is made of Al material, the weight is significantly reduced and the size is also reduced.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1a is a plan view of a low-temperature side heat exchanger for a Stirling engine according to an embodiment of the present invention, FIG. 1b is a partially enlarged view thereof, and FIG. . In these figures, 20
is a cylindrical housing. Reference numeral 24 denotes a heat exchanger main body made of a thick-walled aluminum pipe, in which minute grooves, for example, 0.5 mm in width, 2 mm in height, and 1 mm in pitch, are formed along the axial direction on the inner circumference. The heat exchanger main body 24 is inserted into the housing 20, and has sealing parts 24 provided at its upper and lower ends.
b is fixed within the housing 20 by closely contacting the inner wall surface of the housing 20 over the entire circumference. A cooling water flow path is formed between the outer peripheral wall surface of the heat exchanger main body 24 other than the sealing portion 24b and the inner wall surface of the housing 20. In addition, fins 23 are formed on the outer peripheral wall surface of the heat exchanger body 24 that forms the cooling water flow path to increase the contact area between the heat exchanger body and water, which is the cooling fluid, and to improve cooling efficiency. has been done. 25 is a cast iron liner press-fitted into the inner periphery of the heat exchanger body 24, and 26 is a minute He flow path formed between the liner 25 and a groove in the inner periphery of the heat exchanger body 24. Further, the side wall of the housing 20 is provided with a cooling water inlet 21 through which water as a cooling fluid flows in, and a cooling water outlet 22 through which the cooling water flows out.

Next, the operation will be explained.

High temperature He (approximately 80℃), which is a heat exchange fluid,
Enters from the entrance (upper side) of He flow path 26, and He flow path 2
6 flowing at high speed. In addition, water (approximately 10°C), which is a cooling fluid, enters from the cooling water inlet 21 and the fin 2
3 and cools the He flowing through the He channel 26 by heat transfer. The He (approximately 25° C.) cooled while passing through the He channel 26 flows out from the outlet of the He channel 26 . In addition, water, which is a cooling fluid, is He
It removes heat from the cooling water and flows out from the cooling water outlet 22. The fins 23 increase the heat transfer surface area on the water side and improve heat exchange efficiency.

In this embodiment, the He flow path 26 can be made smaller than before while keeping the contact heat transfer area the same as the conventional device, increasing the flow velocity and improving the heat transfer coefficient. The number of heat exchangers may be small, and the diameter of the heat exchanger can be reduced. Furthermore, the dead volume of the low-temperature side heat exchanger is smaller than that of a conventional shell-and-tube heat exchanger, and engine efficiency is also increased.

In the above embodiment, the liner is fixed to the heat exchanger body by press fitting, but the liner may be fixed by shrink fitting or cold fitting. Further, the width, pitch, height, etc. of the fins on the water side and the grooves on the inner circumferential side of the heat exchanger main body are not specified, and any shape may be used as long as the shape has a high transmission efficiency. Furthermore, although cast iron was used as the liner material in this example, a liner made of Al may also be used.
Materials are not specified.

In addition, in the above embodiment, the case where the low temperature side heat exchanger of the present invention is applied to a Stirling engine has been explained. ), GM
It may also be used in cycle engines and other heat engines. Further, the working fluid (heat exchange fluid) is not limited to He.

Furthermore, in the above embodiment, a housing was provided on the outer periphery of the low temperature side heat exchanger to form a water flow path, but as shown in FIG. 2, the high temperature side heat exchanger 29 of the engine may be provided with a housing. Accordingly, the low-temperature side heat exchanger can be further downsized (reduced in diameter). In FIG. 2, the same reference numerals as in FIG. 1 indicate the same parts, and 27 is an O-ring for preventing the cooling water from getting wet.

Further, as shown in FIG. 3, a protrusion 28 on the outer periphery of the liner 28 is fitted into a groove in the heat exchanger body 24.
a, and in combination with the micro grooves of the heat exchanger body.
By configuring the He flow path, the width of the groove formed in the heat exchanger body can be made wider than in the above embodiment, and the groove can be easily processed.

〔Effect of the invention〕

As described above, according to the present invention, a large number of minute grooves are provided in the inner circumferential portion of a thick-walled aluminum pipe, and a liner is press-fitted into the thick-walled pipe to form the minute grooves for the flow of heat exchange fluid. Since the low-temperature side heat exchanger is constructed by providing cooling fins on the outer periphery of the thick-walled pipe, there is no need for the brazing process of conventional equipment, making the work extremely simple.
The device can be made at low cost. In addition, since most of the material is made of aluminum, it is very lightweight, and the flow path is made smaller while keeping the contact heat transfer area the same as before, allowing the heat exchange fluid to flow at high speed to improve the heat transfer coefficient. Since the number of heat exchangers is reduced, a compact low-temperature side heat exchanger can be obtained.

[Brief explanation of the drawing]

FIG. 1a is a plan view of a low-temperature side heat exchanger according to an embodiment of the present invention, FIG. 1b is a partially enlarged view thereof, FIG. 1c is a sectional configuration diagram of the low-temperature side heat exchanger, Figure a is a plan view of a low-temperature side heat exchanger according to another embodiment of the present invention, Figure 2 b is a partially enlarged view thereof, and Figure 2 c
3 is a cross-sectional configuration diagram of the low-temperature side heat exchanger, FIG. 3a is a plan view of a low-temperature side heat exchanger according to yet another embodiment of the present invention, FIG. 3b is a partially enlarged view thereof, and FIG. 3c
4 is a cross-sectional diagram showing the heat exchanger section of a conventional Stirling engine. FIG. 5 is a cross-sectional diagram of a conventional shell-and-tube type low-temperature heat exchanger. It is. 20...Housing, 21...Cooling water inlet, 22...
Cooling water outlet, 23...fin, 24...heat exchanger body, 25...liner, 26...He channel, 27...O ring, 28...liner with protrusion, 29...high temperature heat exchanger wall. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. A low-temperature side heat exchanger for cooling a working fluid of a heat engine, comprising: a cylindrical housing; an outer circumferential wall surface of the housing; and an inner wall surface of the housing that is inserted and fixed into the housing. A heat exchanger body that forms a flow path for cooling fluid between the heat exchanger body and has minute grooves along the axial direction on its inner circumference to increase the contact area with the cooling fluid on the outer circumferential wall surface. Aluminum fins are formed integrally with the outer peripheral wall surface, and have sealing parts at the upper and lower ends of the outer peripheral part that are in close contact with the inner surface of the housing and seal the area where the cooling fluid flow path is formed. A low-temperature side of a heat engine, comprising: a heat exchanger body made of a rod-shaped body; and a liner press-fitted into the inner periphery of the heat exchanger body and using the grooves as flow paths for a fluid to be cooled. Heat exchanger. 2. A low-temperature side heat exchanger for a heat engine according to claim 1, wherein the liner has a protrusion formed on its outer peripheral portion to fit into a part of the groove of the heat exchanger body. vessel. 3. The low-temperature side heat exchanger for a heat engine according to claim 1 or 2, wherein the heat engine is an engine using a Stirling cycle. 4 Claims 1 to 3, characterized in that the heat exchange wall of the heat engine is the housing.
A low-temperature side heat exchanger for a heat engine according to any of paragraphs.