JPS60101251A - Stirling engine - Google Patents

Abstract

PURPOSE:To reduce loss of thermal conduction of a regenerator and improve thermal efficiency by arranging the regenerator having a heat accumulating material in a piston of a stirling engine. CONSTITUTION:A heat absorbing fin 1a is provided on an outer wall of a first cylinder 1 and a radiating fin 1b is provided in the first cylinder heat from a heating device 25 is transferred to working gas in a working space 22 high temperature. A first sliding body 10 being a self-lubricating material, a sealing body 11, and a second sliding body 12 are provided in a first piston 7, while a regenerator chamber 7c filled with steel wool, etc., is provided. The working gas is allowed by reciprocating motion of the first piston 7 to flow from the high temperature working space via a fluid passage constructed by a communication hole 13 on the upper part of the first piston a communication hole 14 on the lower part of the regenerator chamber 7c and in said chamber, and a heat exchanging flow passage of the sliding part 7b to the low temperature working space vice versa. A cooling water jacket 6 is provided outside the second cylinder 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement of a Stirling engine as an external heat engine that obtains work by imparting thermal energy to a sealed working gas to perform a Stirling cycle.

[Prior art]

This type of engine has been well known for a long time, but recently it has attracted much attention due to its high theoretical thermal efficiency, non-pollution, and resource saving.

However, as a patent for this engine, a patent application filed in 1983
-66805 and Utility Model Application No. 52-80587, it is important for the practical use of engines that the high-temperature side forming members, especially the heat exchangers, have a simple structure and generate as little thermal stress as possible. It is clear that it is necessary to reduce heat loss due to heat conduction from the high-temperature side forming members to the low-temperature side forming members and improve the thermal efficiency of the engine. In particular, heat conduction loss in the regenerator is also an important factor that reduces the thermal efficiency of the engine.

As mentioned above, there are various problems in the practical application of this engine, but no particular method or structure has been developed yet.

[Summary of the invention]

This invention was made in view of these points,
The present invention provides a Stirling engine with low heat conduction loss in the regenerator and high thermal efficiency.

An embodiment of the present invention shown in FIGS. 1 to 5 will be described in detail below. In FIG. 1, (1) is a cylindrical first cylinder made of heat-resistant metal and closed at one end. (1a) is a heating medium (herein referred to as combustion gas) supplied from a heating device installed in the upper part of the cylinder. In order to reduce the thermal stress acting on the first cylinder (1), there are a plurality of notches in the longitudinal direction, and a heat exchange load is applied so that the wall temperature of the first cylinder (1) in the longitudinal direction is almost constant. (1b) is an endothermic fin whose heat transfer area is increased from small to large in order to keep the rate L1 (lca 'hr m) constant from the side near the heating device) to the downstream side. In order to radiate heat energy given to the first cylinder (1) to the working gas flowing within the cylinder, the first cylinder (1)
A plurality of heat dissipating fins are protruded from the inner wall of the cylinder (1) on the circumference in the longitudinal direction of the cylinder, and the first cylinder (1) has a plurality of notches in the longitudinal direction to reduce thermal stress acting on the first cylinder (1). Second
The figure shows a cylinder plane cross-sectional view of the IA-IA cross section in Fig. 1 viewed from the missing part, and Fig. 8 shows the IB-IIIB longitudinal 1Ill in Fig. 2.
A vertical cross-sectional view of the cylinder viewed from the fr plane is shown, showing the first cylinder (1), the heat absorption fins (1a), and the heat radiation fins (
The configuration of 1b) is shown. (1c) is the first cylinder (1)
It is a flange-shaped cylinder flange installed in the cylinder. (5
) is a second cylinder made of copper-based or aluminum-based metal with extremely good thermal conductivity in a cylindrical shape, and whose inner wall is subjected to corrosion-resistant and wear-resistant treatment by plating or the like. (5a) is a plurality of second cooling fins protruding from the circumference of the second cylinder (6) in the longitudinal direction of the body in order to cool the working gas inside the cylinder.

(5b) has a plurality of flowing water holes (5c) that uniformize the flow of the cooling medium over the entire surface of the fin in order to transfer the amount of heat absorbed from the working gas by the second cooling fin (5a) to the cooling medium (water in this case). A plurality of first cooling fins are formed in the shape of an open annular plate and are fixed to each other with a predetermined gap in the longitudinal direction of the second cylinder (5). (6) is the second cylinder (
6) in a predetermined position and is made of at least a metal with lower thermal conductivity than the second cylinder (5).
It is being In this embodiment, the housing (6) also serves as a cooling water jacket serving as a container for the cooling medium, and (6a) and (6b) are cooling water inlet holes and outlet holes. In addition, as can be seen from the figure, the first cylinder (1) and the second cylinder (5) have a fixed seal system on the cylindrical surface.
The airtightness inside the cylinder is maintained by an elastic airtight device (4) such as an O-ring, and in this embodiment, the first cylinder (1) side is simply a cylindrical shaft surface, and the second cylinder (5) side is simply a cylindrical axial surface. It has a structure with a groove for the air sealing device (4) on the large surface of the shaft, and the shaft diameters of the first cylinder (1) and the second cylinder (5) meet the requirements of the second cylinder (5)>the first cylinder (1) and , the diameter difference between both shafts was set to be greater than or equal to the amount of deformation of the first cylinder (1) due to thermal stress. (2) has poor thermal conductivity to keep the first cylinder (1) and the second cylinder (5) in a predetermined position, in other words, the first cylinder (1) and the housing (6) in a predetermined positional relationship. This floating flange (2) is a floating flange made of metal.
and the cooling water jacket (6) are completely fixed with the fixing bolts (3), and the floating flange (2) and the first cylinder (
1) is semi-fixed with a predetermined gap, that is, a gap greater than the amount of deformation of the first cylinder flange (1c) due to thermal stress of the first cylinder (1). According to this configuration, during engine operation, the engine is almost fixed between the upper surface of the first cylinder flange (IC), the floating flange (2), and the cooling water jacket (6), but the first cylinder (1) Since the amount of deformation due to thermal stress is not restricted by the floating flange (2) or the cooling water jacket (6), it is possible to improve the durability of the first cylinder (1).

(7) divides the inside of the first cylinder (x) and the X2 cylinder (5) into a high-temperature operating space (2) and a low-temperature operating space (2), and is capable of reciprocating movement so that the volumes of both operating spaces can be changed. The first piston (7a) has a cylindrical hollow structure and is made of heat-resistant metal, and the body has heat dissipation fins (1) of the first cylinder (1).
b) and a first piston head portion having a predetermined length capable of heat exchange. (7b) is the outer diameter of the second cylinder (5) having heat absorption fins (5a) and a predetermined heat exchange flow path;
It has a predetermined length of the heat exchange body, has a cylindrical hollow structure, and has an annular first sliding body α0 made of a self-lubricating material, an airtight body Q, and a gas-tight body Q and jl from the upper side of the body, and the lower part thereof. It has a plurality of flow holes 04 at the bottom thereof, and a sliding surface made of a self-lubricating material and a plurality of protruding sliding surfaces at the lowest part after passing through the required length of the heat exchange cylinder. A light alloy such as aluminum, which is equipped with a second annular sliding body (6) having a plurality of working gas passages formed by grooves cut into the same diameter as the outer diameter of the first piston (7);
The first piston moving part is made of metal with good thermal conductivity.

(7C) is a regenerator section in which a hollow cylindrical regenerator chamber is filled with a wire mesh made of stainless steel, manganin, etc., or a filler such as steel wool. It has a circulation hole 03, and the working gas inside the cylinder is passed through the first
As the piston (7) reciprocates, the heat exchange channel, the circulation hole (6), and the regenerator chamber (
7c], through a flow path consisting of a heat exchange flow path in the first piston sliding part (7b) and a flow hole in the first piston sliding part (7b), from the operating space at both temperatures to the operating space at a low temperature, or from the operating space at a low temperature. The heat conduction loss from the regenerator section to the outside of the engine can be reduced to almost zero by forming the JA so that it can flow from the regenerator to the high-temperature operating space. The reciprocating movement of the first piston (7) connects the drive mechanism 3η, the first piston rod αQ, and the first piston (7) to the central axis of the air supply piston rod OQ caused by deflection of the air supply piston rod OQ. The first
The piston (7) is connected to the second cylinder (5) and the first cylinder (
Smooth reciprocating motion is possible without generating lateral pressure, etc. against the surface, stable performance is achieved without uneven wear on the sliding body QO1@ and the airtight body 0η, and reduction in sliding loss of the sliding part. Obtained over a long period of time.

(The first frame is the second piston, which is the power piston, and the oil is the second piston.
The piston (an airtight sliding body for the purpose of sliding and airtightness of the l barrel) is a rod packing for the purpose of sliding and airtightness of the air supply piston rod 0θ. (Incorporated) is a space on the lower side of the second piston 0#, which is a buffer chamber, and is a chamber that is sealed with working gas at the same pressure level as the inside of the cylinder when not in operation. Ql indicated by a dashed line is a drive mechanism for establishing a cycle of this engine. eυ is a device having a mechanism in which the second piston (c) operates with a predetermined delay phase in the reciprocating motion of the second piston (g) and the first piston (7). To measure the mixing and distribution of the heating medium (fuel and combustion air) from the combustion tube, the Samurai to the heating device near the outer wall head of the first cylinder (1) With this mixing plate, the head of the first cylinder (1) is not directly exposed to the heating medium, and the air holes (Ha)
By selecting the opening ratio of , it is possible to make the wall temperature of the first cylinder (1) approximately equal to -Cζ. (to) is the exhaust hole for the heating medium after heating the first cylinder (1 cylinder).
The figure shows a plan sectional view of the IVc-ffc section of FIG. 1 viewed from the top, and FIG. 5 shows the structure of the sliding body (2). In these figures, the same reference numerals as those in FIG. 1 indicate the same or corresponding parts, and the explanation thereof will be omitted.

In this embodiment configured as described above, the working gas can be sealed in the cylinder, and the first cylinder (1) is heated by the heating device I.
By heating the second cylinder (5) with cooling water and at the same time starting the station operating mechanism a with some kind of starting means, the engine cycle is established and the Stirling engine obtains work from thermal energy. Of course, the following great effects can be expected. That is, the temperature distribution in the first cylinder becomes more or less uniform, and the selection of the material constituting the cylinder becomes easier. In addition, it is difficult to create a bulge that is harmful to the strength of the material. In addition, thermal stress generated in the cylinder body and other parts is extremely small, and reduction in life due to thermal stress fatigue of the material can be prevented as much as possible. Furthermore, the heat conduction loss from the first cylinder to the second cylinder (from the high-temperature side formation to the low-temperature side formation) becomes almost negligible. Furthermore, since the walls of the regenerator are inside the cylinder, the heat conduction loss from the regenerator walls to the outside of the engine is reduced to a negligible level, and the first piston moves smoothly. The service life of self-lubricating materials can be improved, and sliding mechanical losses can be reduced.

In the above embodiments, water was used as the cooling medium and combustion gas was used as the heating medium, but it is needless to mention that air, etc. may be used instead of water, and solar heat or other heating medium may be used instead of combustion gas. .

〔Effect of the invention〕

As described above, according to the present invention, since the regenerator is provided inside the cylinder, the heat conduction loss from the regenerator to the outside of the engine becomes negligibly small, so there are effects such as improving the thermal efficiency of the engine. .

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention, FIG. 2 is a sectional view taken along MA-mA in FIG. 1, and FIG.
4 is a sectional view taken along IVC-IVC in FIG. 1, and FIG. 6 is a sectional view and a front view of the sliding body. In the figure, (1) is a first cylinder, (5) is a second cylinder, (7) is a first piston, 0η is a sliding sealing member, and 04 and θ are communication holes. (7c) is a regenerator. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Masuo Oiwa Figure 1 Figure 2

Claims (1)

[Claims] A piston provided reciprocatingly in a cylinder having a high-temperature operating space and a low-temperature operating space, a regenerator having a heat storage member disposed inside the piston, and the high-temperature operating space disposed between the piston and the cylinder. and a low-temperature operating space, and the piston is provided with a communication hole that bypasses the sliding sealing member to communicate the high-temperature operating space and the low-temperature operating space. Starling institution.