JPH0213145B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to Stirling engines, and in particular to improvements in lubrication methods.

Configuration of a conventional example and its problems FIG. 1 is a diagram showing a schematic configuration of a conventional Stirling engine. 1 is a closed container in which a working fluid is sealed. 2 is a heater for heating the working fluid, 3 is a cooler for cooling the working fluid, and 4 is a regenerator. A displacer 5 is provided so as to be able to move vertically within the closed container 1 while maintaining a narrow gap with the inner wall of the closed container 1;
6 is a support component fixed to the inner wall of the sealed container;
Reference numeral 7 denotes a bearing portion of the support component 6, which is configured to allow the displacer rod 8, which is a part of the displacer 5, to move vertically while sliding;
A piston 10 is provided so as to be able to move vertically and slidably on the inner wall of the closed container 1. One end of the piston 10 is fixed to the inner wall of the closed container 1, and the other end is fixed to the piston 9. This is the load exerted by the piston 9 due to the movement of .

A solid lubricant is applied to the surface of the displacer rod 8 that slides on the bearing 7, and the surface of the inner wall of the bearing 7 that slides on the displacer rod 8.

The operation of the conventional example will be explained below.

When the displacer 5 moves downward, the volume of the compression space 11 decreases and the volume of the expansion space 12 increases. Therefore, the pressure in the compression space 11 is equal to the pressure in the expansion space 1.
2, and this differential pressure causes the cold working fluid in the compression space 11 and the cooler 3 to flow through the regenerator 4 and the heater 2 towards the expansion space 12. At this time, the working fluid is heated by the regenerator 4 and the heater 2. The regenerator 4 is then cooled in reverse. Since the low-temperature working fluid is heated in this way, the compression space 11, the passage 13,
The pressure in the working space including the cooler 3, regenerator 4, heater 2, passage 14, and expansion space 12 increases,
Pull up the piston 9. At this time, the piston 9 performs work against the load 10. On the other hand, as the displacer 5 continues to fall, the pressure of the gas spring 15 gradually increases, and finally the displacer 5 stops falling and begins to rise again. When the displacer 5 rises, the compression space 11
The volume of the expansion space 12 increases and the volume of the expansion space 12 decreases. Therefore, the pressure in the expansion space 12 is equal to the pressure in the compression space 11.
Due to this pressure difference, the hot working fluid in the expansion space 12 and the heater 2 flows through the regenerator 4 and the cooler 3 towards the compression space 11. The working fluid is then cooled by the regenerator 4 and the cooler 3. and regenerator 4
On the contrary, it is heated. In this way, the high temperature working fluid is cooled, so the pressure in the working space is lowered,
Pull up the piston 9. At this time, the piston 9 performs work against the load 10.

On the other hand, as the displacer 5 continues to rise, the pressure in the gas spring 15 gradually decreases, and finally,
The displacer 5 stops rising and now begins to descend in the opposite direction.

In the process of one rotation as described above, the working fluid transfers a part of the heat obtained by the heater 2 to the load 10.
It is used for work on the air, and a part is thrown away into the cooler 3.

On the other hand, as mentioned in the configuration, the surface of the displacer rod 8 that slides on the inner wall of the bearing 7, and the surface of the inner wall of the bearing 7 that slides on the displacer rod 8, these two surfaces are coated with solid lubricant. Since the agent is applied, the display rod 8 and the inner surface of the bearing 7 slide smoothly.

By the way, in the conventional Stirling institution,
Because solid lubricants were used on the sliding surfaces, they gradually wore out during long-term operation, and as a result, metals came into contact with each other, resulting in increased friction loss and damage to the engine. Efficiency decreased, seizure occurred, and sliding became impossible. Furthermore, the wear particles of the solid lubricant can clog the matrix of the regenerator 4, thereby increasing the pressure drop in the regenerator 4, which also reduces the efficiency of the engine.
It entered the heater 2 and decomposed, producing corrosive substances that corroded the sealed container 1 and other parts.

In this way, the disadvantage was that the efficiency and reliability of the engine were reduced.

OBJECTS OF THE INVENTION The present invention aims to eliminate the drawbacks of the conventional Stirling engine as described above, and to provide a highly efficient and reliable Stirling engine.

Structure of the Invention The present invention seals different types of working fluids A and B in a closed container, and condenses one of the fluids in the sliding part of a member that moves freely in the closed container. It allows moving members to move smoothly.

DESCRIPTION OF EMBODIMENTS The configuration of the present invention will be described below. In FIG. 2, reference numeral 16 denotes a closed container in which a working fluid A having a high boiling point and a working fluid B having a lower boiling point than the working fluid A are sealed. 18 is a heater for heating the working fluid, 17 is a cooler for cooling the working fluid, and 19 is a regenerator. 20 is compressed space, 2
1 and 22 are flow paths, 23 is an expansion space, and 24 is a displacer in which a gas spring 25 is movable in the vertical direction within the closed container 16 while maintaining a narrow gap with the inner wall of the closed container 16; 26 is a support component fixed to the inner wall of the closed container 16;
Reference numeral 7 denotes a bearing portion of a support component 26 that is configured to allow a displacer rod 28, which is a part of the displacer 25, to move vertically while sliding; 29, a bearing portion that is slidable on the inner wall of the closed container 16; One end of the piston 30 is fixed to the inner wall of the closed container 16 and the other end is fixed to the piston 29, and the piston 30 is provided so as to be movable in the vertical direction. This is the load on compressors, pumps, etc.

31 is the display rod 28 and the bearing part 27
A tube attached to the outer wall of the bearing part 27 near the sliding part by a method that lowers thermal resistance, such as by brazing,
32 is a groove formed in the inner wall of the bearing portion 27. As shown in FIG. Further, the pipe 31 is designed to allow a coolant to flow therethrough.

Next, the operation will be explained. A working fluid A having a high boiling point such as Chitsuso N ₂ or helium He and a working fluid B having a low boiling point such as water H ₂ O are sealed in the closed container 16 . In the space in the closed container 16 where the working fluid A and the working fluid B exist, the working fluid A and the working fluid B exist in a gas phase except where specifically stated.
Further, a liquid phase in which the working fluid B occupies the majority exists at the bottom of the bounce space. When the displacer 25 moves downward, the volume of the compression space 20 decreases, and conversely, the volume of the expansion space 23 increases. Therefore, the pressure in the compression space 20 becomes higher than the pressure in the expansion space 23,
Due to this pressure difference, the compression space 20 and the cooler 1
A working fluid that is a mixture of low-temperature working fluid A and working fluid B (hereinafter referred to as mixed working fluid) in chamber 7 flows toward expansion space 23 through regenerator 19 and heater 18 . At this time, the mixed working fluid is heated by the regenerator 19 and the heater 18. The regenerator 19 is then cooled in reverse. In this way, the low-temperature mixed working fluid is heated, so the compression space 2
0, the pressure in the working space including the passage 21, the cooler 17, the regenerator 19, the heater 18, the passage 22, and the expansion space 23 becomes high, and the piston 29 is pulled down.
At this time, the piston 29 performs work on the load 30. On the other hand, as the displacer 25 continues to fall, the pressure of the gas spring 24 gradually increases, and finally the displacer 25 stops falling and begins to rise.

When the displacer 25 rises, the volume of the compression space 20 increases and the volume of the expansion space 23 decreases. Therefore, the pressure in the expansion space 23 becomes higher than the pressure in the compression space 20, and due to this pressure difference, the high temperature mixed working fluid in the expansion space 23 and the heater 18 flows through the regenerator 19 and the cooler 17. flowing towards the compression space 20, the mixed working fluid is cooled by the regenerator 19 and the cooler 17, and the regenerator 19 is heated in turn. Since the high temperature mixed working fluid is cooled in this way, the pressure in the working space is lowered and the piston 2
Raise 9. At this time, the piston 29 has a load of 30
work against.

On the other hand, as the displacer 25 continues to rise, the pressure of the gas spring 24 gradually decreases, and finally the displacer 24 stops rising and begins to descend.

In the process described above, the mixed working fluid converts part of the heat obtained by the heater 18 into work for the load 30, and part of it is transferred to the cooler 1.
I will throw it away at 7. On the other hand, the pipe 31 contains Freon,
A coolant such as brine is flowing, so that the bearing portion 27 to which this tube 31 is attached is cooled.
Therefore, the mixed working fluid near the groove portion 32 is cooled,
The working fluid B having a lower boiling point is condensed in the groove 32 to generate a liquid phase. This liquid phase acts as a lubricant between the vertically moving displacer rod 28 and the inner wall of the bearing portion 27, and exhibits the effect of reducing the coefficient of friction.

In this way, unlike conventional Stirling engines, solid lubricants are not used, so the solid lubricants do not wear out over time, and the various disadvantageous phenomena caused by this do not occur. Occurrence can be prevented.

This is because the liquid-phase working fluid B, which is a lubricant, can be continuously and stably supplied to the groove portion 32 by cooling the closed container 16. Moreover, unlike lubricants, there is no need to worry about it entering the heater 18, decomposing, producing carbon, and clogging the matrix of the regenerator 19. In the above embodiment, the heater 1
8, a cooler 17, a regenerator 19, and flow paths 21 and 22 are provided, but instead of these, a heating means for heating the working fluid in the expansion space 23 from outside the wall of the closed container 16, and a compression space 20 are provided. The working fluid in the sealed container 1
It is also possible to provide cooling means for cooling from the outside of the wall of the displacer 25 and a regenerator matrix attached to the surface of the displacer 25 facing the inner wall of the closed container 16. Further, the displacer 25 can also be replaced with a diaphragm.

Effects of the Invention In the present invention, unlike conventional Stirling engines, solid lubricants are not used to lubricate sliding surfaces, but the liquid phase of the working fluid is used as the lubricant. This has the effect of not reducing efficiency and increasing reliability.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a Stirling engine according to an embodiment of the prior art, and FIG. 2 is a schematic diagram of a Stirling engine according to an embodiment of the present invention. 16... Airtight container, 18... Heater, 17...
Cooler, 19... Regenerator, 25... Displacer, 29... Piston, 30... Load, 31...
Pipe, 32...Groove, 34...Liquid phase portion of working fluid.

Claims (1)

[Claims] 1. A closed container, a working fluid A and a working fluid B sealed in the sealed container, and a space inside the sealed container into an expansion space where a high temperature working fluid exists and a compression space where a low temperature working fluid exists. a displacer that moves relative to the sealed container through a gap or in contact with the inner wall of the sealed container so as to divide the container; a flow path that communicates the expansion space and the compression space; A heater/regenerator/cooler C provided sequentially from the expansion space side to the compression space side; a piston that moves relative to the closed container and receives work from the working fluid; and a piston provided within the closed container. a bearing that is part of the displacer and is provided so as to be slidably movable through a narrow gap with the bearing; Stirling engine with means D for cooling the working fluid.