JP2000186618A - Cylinder block for heat engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve workability so as to lower a cost and also improve working accuracy so as to improve heat exchange performance and reliability by manufacturing the heat exchanger of a stirling refrigerating machine by a simple structure and lost wax casting. SOLUTION: On the inner and outer surfaces in a top heat exchange housing 32 forming an expansion cylinder block, a fin 38 for cooling a refrigerant having cryogenic effect and a working gas channel 39 are integrally formed by lost wax casting, and also on the inner and outer surfaces of a radiating heat exchanger 27, a fin 50 and a working gas channel 51 are integrally formed similarly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Stirling refrigerating machine which can be used for freezing and cooling in all industrial fields such as food distribution, environmental testing, medical care, biotechnology, semiconductor manufacturing, and home appliances. .

[0002]

2. Description of the Related Art In recent years, as a refrigeration system that substitutes CFCs for global environmental problems, the operating temperature of the refrigeration system is wider than that of conventional refrigeration systems. Including
Low-temperature liquid circulators, low-temperature thermostats, constant-temperature baths, heat shock test equipment, freeze dryers, temperature characteristic test equipment, blood / cell storage devices, cold coolers, and various other types of cold heat equipment such as cooling equipment The Stirling refrigerator has been spotlighted as a refrigerator that is applicable, compact, has a high coefficient of performance, and has good energy efficiency.

In a Stirling refrigerator, a working gas flows between a compression chamber (high-temperature chamber) and an expansion chamber (low-temperature chamber), and a heat-absorbing heat exchanger (low-temperature chamber) disposed along this flow path. Side heat exchanger) and heat exchanger for heat dissipation (high temperature side heat exchanger)
As a result, heat exchange is performed with the cryogenic refrigerant and the radiating refrigerant, respectively. Conventionally, as a heat exchanger, for example, there is a shell-and-tube heat exchanger, a plate-fin heat exchanger, or the like.

[0004]

The heat exchanger in the Stirling refrigerator has a flow path which flows uniformly without partially obstructing the flow of the working gas in order to improve the heat exchange performance and reliability. In addition, it is required that fins with uniform thickness and precision are formed, and furthermore, the heat exchanger itself is excellent in workability to realize low cost, and the whole structure of the Stirling refrigerator is simplified. Is required.

[0005] The shell and tube type heat exchanger has a problem in that it takes time and effort to assemble it, and there is a problem in reducing the cost. The plate fin type heat exchanger also has a problem in cost. An object of the present invention is to solve the above problems.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a cylindrical top heat exchange housing having a top wall and a side wall, and a heat exchange housing disposed inside the top heat exchange housing. A cylinder block having an inner cylinder on which a piston or a displacer slides, and a shaft that forms a flow path for a working gas together with an outer peripheral surface of the inner cylinder on an inner peripheral surface on a distal end side of the top heat exchange housing. An annular recess is formed on the inner peripheral surface on the base end side of the top heat exchange housing together with the outer peripheral surface of the inner cylinder to form a flow path for a working gas regenerator. The top heat exchange housing has a configuration formed by lost wax casting, and provides a cylinder block for a heat engine.

According to another aspect of the present invention, there is provided a cylinder block having an inner cylinder on which a piston or a displacer of a heat engine slides. A heat exchanger comprising an exchange housing and a heat exchanger body inserted and fixed inside the exchange housing is provided, and the heat exchanger body has a heat exchange fin formed on an outer peripheral surface thereof. On the inner peripheral surface thereof, an axial linear narrow groove forming a flow path for working gas is formed along with the outer peripheral surface of the inner cylinder, and the annular heat exchange housing, the heat exchanger body, The annular heat exchange housing has a refrigerant inlet and a refrigerant outlet formed therein so that the space between the refrigerant passages communicates with the refrigerant passage. Is formed by cast iron, heat exchanger body provides a cylinder block for thermal engine which is a formed structure by a lost wax casting.

Further, in order to solve the above-mentioned problems, the present invention provides a cylindrical top heat exchange housing having a top wall and a side wall, and a piston or a displacer of a heat engine provided in the top heat exchange housing. A cylinder block having a sliding inner cylinder, wherein an inner peripheral surface on the distal end side of the top heat exchange housing has an axial straight line forming a flow path for working gas together with an outer peripheral surface of the inner cylinder. An annular concave portion is formed on the inner peripheral surface on the base end side of the top heat exchange housing together with the outer peripheral surface of the inner cylinder to form a flow path for a regenerator for working gas. A heat exchanger including a cylindrical annular heat exchange housing and a heat exchanger body inserted and fixed inside the housing is disposed outside the inner cylinder, and the heat exchanger body is On its outer peripheral surface, fins for heat exchange are formed, and on its inner peripheral surface, there are formed axially linear narrow grooves forming a flow path for working gas together with the outer peripheral surface of the inner cylinder. A space between the annular heat exchange housing and the heat exchanger body is a refrigerant passage, and a refrigerant inlet and a refrigerant outlet are formed in the annular heat exchange housing so that the refrigerant passages communicate with each other. The top heat exchange housing and the heat exchanger body are each made by lost wax casting, and the annular heat exchange housing is
A cylinder block for a heat engine, wherein the cylinder block is formed by lost wax casting or cast iron.

The top heat exchange housing has fins formed integrally with the top heat exchange housing or fins formed separately and attached later on the outer peripheral surface on the distal end side.

[0010] The heat engine is a Stirling cycle device, a Vilmier cycle device, a Kuku-Javorov cycle device, or the like.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on embodiments with reference to the drawings. 1 to 5 are diagrams illustrating an embodiment of a heat engine cylinder block according to the present invention. FIG. 1 is a diagram illustrating a Stirling example of a heat engine to which the heat engine cylinder block according to the present invention is applied. FIG. 1 is an overall view illustrating a refrigerator 1. Stirling refrigerator 1
Is formed of a casting, and the inside thereof is held in a semi-sealed state. The interior of the housing 2 is partitioned into a motor chamber 4 and a crank chamber 5 by a partition wall 3.

The motor chamber 4 is provided with a motor 6 capable of rotating forward and reverse, and the crank chamber 5 has a crankshaft 7 for converting the rotation of the motor 6 into reciprocating motion, a connecting rod 8, A cross guide head 9 is provided and functions as a driving unit of the Stirling refrigerator 1.

The two crank parts 1 of the crankshaft 7
0 and 11 are formed with a phase difference so that the crank portion 11 moves ahead of the crank portion 10 when the motor 6 rotates forward. As this phase difference, a phase difference of about 90 degrees is generally adopted.

A compression cylinder 1 is provided above the crank chamber 5.
2 and an expansion cylinder 13 extending slightly above the compression cylinder 12. Compression cylinder 12
The working gas, for example, helium, hydrogen, nitrogen, or the like is sealed in the expansion cylinder 13 and the housing 2. The compression cylinder 12 has a compression cylinder block 14 fixed to the housing 2 by bolts or the like. A compression piston 15 reciprocates in the space of the compression cylinder block 14. The upper part (compression space) of this space is the high-temperature chamber 16, and the working gas therein is compressed to a high temperature.

The compression piston rod 17 connects the compression piston 15 and the cross guide head 9, and the compression cylinder 1
2 and a crank chamber 5 extend through an oil seal 19. Since the sliding direction of the reciprocating compression piston 15 is reversed at the top dead center and the bottom dead center, the speed becomes zero, and the speed is slow near the top dead center and the bottom dead center, and the change amount of the volume per unit time is also small. It is small and has the highest speed at each intermediate point when moving from bottom dead center to top dead center and from top dead center to bottom dead center, and the amount of change in volume due to movement of the compression piston 15 per unit time is also maximum. Becomes

On the other hand, the expansion cylinder 13 is
Cylinder block 2 fixed to bolts and the like
The expansion piston 21 reciprocates in the space of the expansion cylinder block 20, and the upper part (expansion space) of the space is a low-temperature chamber 22, in which the working gas expands to a low temperature. . The expansion piston rod 23 connects the expansion piston 21 and the cross guide head 18, and extends between the expansion cylinder 13 and the crank chamber 5 through an oil seal 25. The expansion piston 21 is
It moves ahead 90 degrees more.

The expansion cylinder block 20 is provided with a manifold 26 through which a working gas flows into and out of the compression space of the compression cylinder 12 so as to communicate therewith. Further, a heat radiation heat exchanger (high-temperature side heat exchanger) 27, A regenerator 28 and a heat exchanger for cooling (low-temperature side heat exchanger) 29 are annularly arranged so as to sequentially communicate with each other.

In the vicinity of the upper end of the compression cylinder block 14, a communication hole 3 for communicating the high temperature chamber 16 with the manifold 26 is provided.
0 is formed, whereby the high-temperature chamber 16 and the low-temperature chamber 22 sequentially communicate with each other via the communication hole 30, the manifold 26, the heat exchanger 27 for heat radiation, the regenerator 28, and the heat exchanger 29 for cooling. It is configured as follows.

A cylinder block for a heat engine according to the present invention will be described in detail with reference to FIGS. In FIG. 2, the expansion cylinder block 20 includes an inner cylinder 31.
And a heat-radiating heat exchanger 27 and a low-temperature-side heat exchange housing (top heat exchange housing) 32 disposed concentrically outside the lower part of the inner cylinder 31. The inner cylinder 31 forms a cylinder space in which the expansion piston 21 reciprocates, and the upper cylinder 33 and the lower cylinder 34 may be combined via the O-ring 24 or may be manufactured integrally.

FIG. 3A shows the low-temperature side heat exchange housing 32.
3B is a sectional view taken along the line AA in FIG. 3A, and FIG. 3C is an enlarged view of a main part. 2 and 3, the low-temperature side heat exchange housing 32 has a cylindrical shape, and has a top wall 35, a side wall 36, and a lower flange portion 37.
It is composed of Fins 38 and intermediate flanges 38 'are formed on the outer peripheral surface of the side wall 36 at the distal end side (upper side in the figure). The top wall 35 is composed of a flange top wall portion 35 'and a central top wall portion 35 ", and the central top wall portion 35" is welded to the inner surface of the top end of the side wall 36 as shown by W in FIG. Be integrated. Further, the top wall 35 may be formed integrally with the side wall 36 by lost wax casting described later.

The inner peripheral surface of the tip of the side wall 36 is in close contact with the outer surface of the inner cylinder 31 and has a narrow groove 39 in the longitudinal direction.
Are formed at intervals in the circumferential direction. The narrow groove 39 and the outer surface of the inner cylinder 31 form a flow path of the working gas. Thus, the top part (cold head 40) of the low-temperature side heat exchange housing 32 forms the cooling heat exchanger (low-temperature side heat exchanger) 29. The cold head 40 is in contact with air, water, alcohol, or other cold refrigerant to cool the cold refrigerant.

An annular recess 41 is formed on the inner peripheral surface at the center of the low-temperature side heat exchange housing 32,
Together with this, an annular space 42 is formed, in which a regenerator material such as a metal mesh is filled to form a regenerator 28. Flange 3 at lower end of low-temperature side heat exchange housing 32
7 is mounted on the flange 43 at the upper end of the heat exchanger 27 for heat radiation.

The low-temperature side heat exchange housing 32 of the present invention comprises:
Cast by a lost wax method using a material such as SUS. That is, the low-temperature side heat exchange housing 32 of the present invention
The cooling fins 38 are formed integrally by lost wax casting such that the cooling fins 38 are formed on the outer peripheral surface and the narrow grooves 39 for the flow path of the working gas are formed on the inner peripheral surface.

Since the cooling fins 38 formed on the outer surface of the low-temperature heat exchange housing 32 manufactured by the lost wax casting are precisely cast into fine folds, the heat-exchange housing 32 is extremely excellent in heat radiation performance. The axial narrow groove 39 formed on the inner surface is also precisely cast, so that the working gas can flow uniformly without partially obstructing the flow, thereby improving the refrigerating performance.

FIG. 4B is a sectional view taken along line BB of FIG. 4A, and FIG. 4C is an enlarged view of a main part. 2 and 4, the heat-radiating heat exchanger 27 is an annular-type heat exchanger as shown in FIGS. 2 and 4, and the heat-radiating heat exchanger 27 is a high-temperature-side heat exchange housing (annular). Heat exchange housing) 44 and a heat exchanger body 45 concentrically inserted therein, and a flow for a heat exchange medium such as cooling water between the high temperature side heat exchange housing 44 and the heat exchanger body 45. A passage 46 is formed, and the upper and lower ends are sealed with a seal 47. An inflow port 48 and an outflow port 49 are formed so as to communicate with the flow path 46.

A large number of radiating fins 50 are formed on the outer peripheral wall of the heat exchanger main body 45 facing the flow passage 46, and the inner peripheral wall surface of the heat exchanger main body 45 has a narrow groove along the axial direction. 51
Are formed at regular intervals in the circumferential direction, and form a flow path for a heat exchange fluid such as helium between the inner cylinder 31 and the inner cylinder 31.

In FIG. 1, the heat radiating heat exchanger 27 is connected to a radiator (radiator) 53 via a cooling water circulation pipe 52 and a cooling water pump P1 to circulate the cooling water. The cooling water heated and exchanged by the heat exchanger 27 is cooled by the cooling fan 54 of the radiator 53. The cooling water circulation pipe 52 is connected to a reservoir tank 56 via a reservoir valve 55. The radiator 53 is connected to an air vent 57 and a drain valve 58.

The heat exchanger body 45 of the heat radiating heat exchanger 27 of the present invention is cast from SUS, copper, aluminum or other materials by a lost wax method, and is formed on the outer surface of the heat exchanger body 45. The radiating fins 50 are precisely cast into fine folds, so that they have extremely excellent radiating performance. In addition, the axial narrow groove 51 formed on the inner surface is also precisely and integrally cast, so that the working gas can flow uniformly without partially obstructing the flow, thereby improving the refrigerating performance. The high-temperature side heat exchange housing 44 may be formed by lost wax casting as described above, or may be manufactured by ordinary cast iron.

FIG. 5 is a view for explaining a modification of the low-temperature side heat exchange housing of the expansion cylinder block 20 according to the present invention. FIG. 5 (a) shows a low-temperature side heat exchange housing 32 'which is a first modification. The low-temperature side heat exchange housing 32' has fins and flanges integrally formed on its outer peripheral surface by lost wax casting. Not what it is.
In the first modified example, the heat exchanger is used in a state in which fins and the like are not attached (the state of FIG. 5A) and exchanges heat with a refrigerant such as air in contact with the peripheral surface, or the outer peripheral surface thereof. It is used by winding a heat exchange tube (not shown) through which a refrigerant or the like to be heat-exchanged is passed, or by forming an external fin and a flange on a peripheral surface of the tube later.

FIG. 5B shows a second modification in which the external fins and the flange are formed by retrofitting. Low temperature side heat exchange housing 32 "which is a second modification.
Is formed by attaching an outer fin 59 made of a material such as Cu, Al, SUS or the like in an annular shape and flanges 60, 61 made of the same material as the housing by welding or the like. Such outer fins may be spiral or other shapes.

Next, the operation of the Stirling refrigerator of the above embodiment of the present invention will be described. The motor 6 rotates the crankshaft 7 in the forward direction, and the crank portions 10 and 11 in the crank chamber 5 rotate with a phase shift of 90 degrees. The cross guide heads 9 and 18 reciprocate via connecting rods 8 and 8 'rotatably connected to the crank portions 10 and 11. The compression piston 15 and the expansion piston 21 connected to the cross guide heads 9 and 18 via the compression piston rod 17 and the expansion piston rod 23 reciprocate with a phase difference of 90 degrees from each other.

While the expansion piston 21 moves slowly near the top dead center 90 degrees ahead of the other, the compression piston 15 moves rapidly near the middle toward the top dead center to perform the compression operation of the working gas. The compressed working gas flows through the communication hole 30 and the manifold 26 into the narrow groove 51 of the heat exchanger 27 for heat radiation. The working gas that has radiated heat to the cooling water in the radiating heat exchanger 27 is cooled by the regenerator 28 and is cooled.
And flows into the low-temperature chamber 22 (expansion space) through the groove.

When the compression piston 15 is slowly moving near the top dead center, the expansion piston 21 moves rapidly toward the bottom dead center, and the working gas flowing into the low temperature chamber 22 (expansion space) expands rapidly. Cold heat is generated. Thereby, the cold head 40 is cooled to a low temperature.

Then, in the cold head 40, the cold refrigerant in contact with the cooling fins 38 is cooled. When the expansion piston 21 moves from the bottom dead center to the top dead center, the compression piston 15 moves from the intermediate position to the bottom dead center, and the working gas flows from the low temperature chamber 22 through the narrow groove 39 of the cold head 40 to the regenerator 28. Regenerator 2
Store heat in 8. The cold stored in the regenerator 28 is reused to cool the working gas sent from the high-temperature chamber 16 through the heat-radiating heat exchanger 27 again as described above.

The cold refrigerant cooled in the cold head 40 cools various cold heat utilization equipment. For example, the cold refrigerant is sent to a cold refrigerant pipe in a cold utilization device such as a freezer, and performs freezing or cooling in the cold utilization device. It is circulated back to the cold head 40 and cooled again.

The cooling water exchanged in the heat-radiating heat exchanger 27 flows from the cooling-water circulation line 52 to the radiator, where it is cooled by the cooling fan and circulated to the heat-radiating heat exchanger 27 again.

In the above embodiment, the two-piston type Stirling refrigerator 1 is used. However, it is needless to say that another type of Stirling refrigerator 1 such as a displacer type may be used.

[0038]

According to the Stirling cooling device of the present invention, the following effects can be obtained. (1) A working gas flow path is integrally formed on the inner surface of the top heat exchange housing constituting the expansion cylinder block,
Or, by forming the fins for cooling the hot and cold refrigerant integrally on the outer surface in addition to the working gas flow path on the inner surface, particularly by forming precisely by lost wax casting, workability is improved, and the Stirling refrigerator itself is improved. The structure is extremely simple and the price is low, and the flow of working gas in the groove is uniform without being partially obstructed. Performance and reliability are improved.

(2) Since the annular heat exchange housing and the heat exchanger body of the heat radiating heat exchanger are also integrally formed, they can be precisely formed particularly by lost wax casting.
The workability is improved, the cost is reduced, and the flow of the working gas in the groove is made to flow uniformly without being partially obstructed, so that the heat exchange performance and reliability are improved.

(3) By using a low-melting-point refrigerant such as ethyl alcohol, nitrogen or helium as a working gas as a refrigerant other than chlorofluorocarbon, it is possible to provide a chlorofluorocarbon alternative refrigerator excellent in environmental protection.

[Brief description of the drawings]

FIG. 1 is an overall view illustrating a Stirling refrigerator according to the present invention.

FIG. 2 is a diagram illustrating an expansion cylinder block as an embodiment of the cylinder block for a heat engine according to the present invention;
It is sectional drawing.

3 is a cross-sectional view and a plan view illustrating a low-temperature side heat exchange housing (top heat exchange housing) of the expansion cylinder block of FIG. 2;

FIG. 4 is a cross-sectional view and a plan view illustrating a high-temperature side heat exchange housing (annular heat exchange housing) of the expansion cylinder block of FIG. 2;

FIG. 5 is a cross-sectional view illustrating first and second modified examples of the low-temperature side heat exchange housing of the expansion cylinder block according to the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Stirling refrigerator 2 Housing 6 Motor 14 Compression cylinder block 15 Compression piston 20 Expansion cylinder block 21 Expansion piston 27 Heat dissipation heat exchanger 28 Regenerator 29 Cooling heat exchanger 32, 32 ', 32 "Low-temperature side heat exchange housing ( Top heat exchange housing) 38 Cooling fin 38 'Intermediate flange 39, 51 Narrow groove 41 Annular recess for regenerator 44 High temperature side heat exchange housing (annular heat exchange housing) 45 Heat exchanger body 50 Heat radiating fin 53 Radiator 59 Separate Cooling fins 60, 61 for retrofitting Flanges for retrofitting separately

Claims (5)

[Claims] 1. A cylinder block having a cylindrical top heat exchange housing having a top wall and a side wall, and an inner cylinder disposed in the top heat exchange housing and in which a piston or a displacer of a heat engine slides. In the inner peripheral surface on the distal end side of the top heat exchange housing, there is formed a linear narrow groove in the axial direction that forms a working gas flow path together with the outer peripheral surface of the inner cylinder. An annular concave portion is formed on the inner peripheral surface on the base end side of the exchange housing, together with the outer peripheral surface of the inner cylinder, to form a flow path for a regenerator for the working gas. A cylinder block for a heat engine, wherein the cylinder block is formed by: 2. A cylinder block having an inner cylinder on which a piston or a displacer of a heat engine slides, wherein a cylindrical annular heat exchange housing and a heat exchanger inserted and fixed inside the housing are provided outside the inner cylinder. A heat exchanger comprising a heat exchanger body is provided.The heat exchanger body has fins for heat exchange formed on an outer peripheral surface thereof, and an inner peripheral surface of the inner cylinder has a fin for heat exchange. An axial linear narrow groove forming a flow path for working gas is formed together with the outer peripheral surface, and a space between the annular heat exchange housing and the heat exchanger body is a refrigerant passage, and the refrigerant is So that the passages communicate
The annular heat exchange housing has a refrigerant inlet and a refrigerant outlet formed therein, the annular heat exchange housing is formed by lost wax casting or cast iron, and the heat exchanger body is formed by lost wax casting. A cylinder block for a heat engine. 3. A cylinder block having a cylindrical top heat exchange housing having a top wall and side walls, and an inner cylinder disposed within the top heat exchange housing and on which a piston or displacer of a heat engine slides. In the inner peripheral surface on the distal end side of the top heat exchange housing, there is formed a linear narrow groove in the axial direction that forms a working gas flow path together with the outer peripheral surface of the inner cylinder. An annular concave portion is formed on the inner peripheral surface on the base end side of the exchange housing, together with the outer peripheral surface of the inner cylinder, to form a flow path for a regenerator of the working gas. A heat exchanger comprising an annular heat exchange housing and a heat exchanger body inserted and fixed inside the housing is disposed, and the heat exchanger body has heat exchange fins formed on an outer peripheral surface thereof. The inner peripheral surface is formed with a linear narrow groove in the axial direction that forms a flow path for the working gas together with the outer peripheral surface of the inner cylinder. The space between the container main body is a refrigerant passage, so that the refrigerant passage communicates,
A coolant inlet and a coolant outlet are formed in the annular heat exchange housing, the top heat exchange housing and the heat exchanger body are formed by lost wax casting, and the annular heat exchange housing is formed by lost wax casting or cast iron. A cylinder block for a heat engine, characterized in that: 4. The top heat exchange housing has a fin formed integrally with the top heat exchange housing or a fin that is separately formed and attached on an outer peripheral surface on a distal end side thereof. The cylinder block for a heat engine according to claim 1. 5. The heat engine according to claim 1, wherein the heat engine is a Stirling cycle device, a Virmier cycle device or a Kuku-Javlov cycle device.
Or a cylinder block for a heat engine according to 4.