JP2000028214A - Regenerator for stirling engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a regenerator for a stirling engine capable of improving heat storage efficiency, and simply assure a regenerator without no individual difference with the low cost. SOLUTION: The present regenerator 11 is adapted such that a heat storage structure 21 is formed into a comb-teeth shaped where plate shaped fins 21b are vertically provided at an equal interval on a flat plate shaped bench 21a with the aid of extrusion molding, and the heat storage structure 21 is deformed into an annular shape and are inserted into a passage, through which working gas passes, formed between an inside cylinder 2 and an outside cylinder 3 of a stirling engine along an outer wall 3d of the inside cylinder 2 such that many fins 21b... form a radial shape, which forms a fluid passage 12' among the fins 21b, through which passage the working gas passes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerator used for a Stirling engine using a Stirling cycle or a reverse Stirling cycle.

[0002]

2. Description of the Related Art The general structure of a Stirling engine using a Stirling cycle or a reverse Stirling cycle such as a Stirling engine, a Stirling refrigerator, and a Vilmier heat pump will be described with reference to a Stirling refrigerator shown in a schematic sectional view of FIG. explain. The cold head 1 having a crown-shaped tip is fitted around the outer cylinder 2 to seal the front end of the outer cylinder 2, and the inner cylinder 3 is coaxially arranged inside the outer cylinder 2.

[0003] A displacer 4 and a compression piston 5 are inserted into the inner cylinder 3 side by side so as to be movable in the axial direction. It is possible. The compression piston 5 is integrated with the leaf spring 8 at the rear end, and the displacer 4 is integrated with the leaf spring 6 via a rod portion 4a penetrating the center of the compression piston 5. The leaf spring 6 and the leaf spring 8 are connected by bolts 13 so that when the compression piston 5 reciprocates, the displacer 4 reciprocates with a predetermined phase difference with respect to the compression piston 5 due to its inertial force. It has become.

A compression space 9 is formed between the displacer 4 and the compression piston 5 substantially at the center of the inner cylinder 3, and an expansion space 10 is formed at the front end of the inner cylinder 3.
Are formed. An opening 3c communicating with the compression space 9 is provided between the front part 3a and the rear part 3b of the inner cylinder 3, and a gap 14 communicating with the expansion space 10 is provided between the inner cylinder 3 and the cold head 1. Have been.

A passage 12 is formed between the outer wall of the inner cylinder 3 and the inner wall of the outer cylinder 2 to communicate the compression space 9 and the expansion space 10 through the opening 3c and the gap 14. The expansion space 10 and the passage 12 are filled with a working gas such as helium. A regenerator 1 in which heat of the working gas is accumulated in the passage 12 and a heat storage body for supplying the accumulated heat to the working gas is disposed.
1 is provided.

In such a Stirling refrigerator, when the compression piston 5 reciprocates by the linear motor 7, the displacer 4 reciprocates with a predetermined phase difference and the compression space 9 reciprocates.
The working gas moves between and the expansion space 10 to perform a reverse Stirling cycle. Then, the heat generated by the compression of the working gas in the compression space 9 is released to the atmosphere through the heat exchange portion 12a of the passage 12, and the working gas further accumulates heat in the regenerator 11 to expand the expansion space 10 Move to.

The working gas cooled by the regenerator 11 is further cooled by expanding in the expansion space 10, and exchanges heat with the cooling object via the cold head 1.
Then, when the working gas moves to the compression space 9 through the passage 12, it takes away the heat stored in the regenerator 11 and
To cool. This operation is repeated to perform freezing.

In such a Stirling engine, various proposals have been made on the shape and manufacturing method of the heat storage body disposed in the regenerator 11. Japanese Patent Application Laid-Open No. 2-143058 discloses a method of forming a heat storage body by stacking a large number of metal wire nets and disposing the heat storage body in a regenerator. JP-A-7-15
The regenerators disclosed in JP-A-1402 and JP-A-7-260380 are designed to obtain a heat storage body by compression-molding a braided thin metal wire. In addition, 4-1
The regenerator disclosed in Japanese Patent No. 29067 and Japanese Patent Application Laid-Open No. 6-249066 is such that a large number of thin tubes and solid rods are tightly bundled so that the longitudinal direction is filled in the regenerator in parallel with the traveling direction of the working gas. Has become.

[0009]

However, the heat storage bodies disclosed in Japanese Patent Application Laid-Open Nos. 2-143058, 7-151402 and 7-260380 disclose a cross-sectional area of a flow path of a working gas. Is difficult to form uniformly in the cross section and in the longitudinal direction, so that the pressure of the working gas becomes non-uniform in the regenerator and individual differences occur. As a result, there is a problem that the pressure loss of the regenerator is increased and the heat storage efficiency is reduced, and the pressure loss of the regenerator has individual differences, resulting in large variations in performance.

[0010] The regenerator disclosed in Japanese Utility Model Laid-Open No. 4-129067 and Japanese Unexamined Patent Application Publication No. 6-249066 has a regenerator in which many thin tubes or solid rods having a diameter of about 0.2 mm are parallel and densely packed. There is a drawback that it is difficult to fill the inside and the production cost increases. Further, there has been a problem that the pressure loss increases due to the partial deformation of the thin tube or the solid rod, the heat storage efficiency of the regenerator is reduced, and the performance varies.

It is an object of the present invention to provide a regenerator for a Stirling engine capable of improving heat storage efficiency, and to easily obtain a regenerator having no individual difference in heat storage efficiency at low cost.

[0012]

According to a first aspect of the present invention, there is provided a stirling engine having a heat storage element disposed on a passage communicating with a compression space and an expansion space of the Stirling engine. In a regenerator of a Stirling engine that accumulates heat possessed by a working gas reciprocating inside and supplies the accumulated heat to the working gas, a plurality of plate members are erected at equal intervals on a flat base. The heat storage body formed integrally with the base is arranged so that the base is annular so that the plate-shaped member is radially directed outward.

According to this configuration, the heat storage body is inserted into the regenerator so that the longitudinal direction of the plate-like member follows the traveling direction of the working gas by deforming the flat base into a ring shape. The working gas passes through the space between the plurality of plate members arranged radially,
When moving from the compression space to the expansion space, heat is absorbed and accumulated in the plate-shaped member and the base, and when moving from the expansion space to the compression space, the heat accumulated from the plate-shaped member and the base is taken out of the heat storage body. Cooling.

According to a second aspect of the present invention, in the regenerator of the Stirling engine according to the first aspect, the tip of the plate-shaped member contacts the inner wall of the passage and the cross-sectional shape of the plate-shaped member is changed. It is characterized by being deformed in a curved shape.

According to this structure, the heat storage body is formed by deforming the flat base into an annular shape, and the height of the plate-shaped member is higher than the difference between the radius of the annular base and the inner radius of the regenerator. The plate-shaped member is inserted into the regenerator so that the plate-shaped member forms an arc and the tip contacts the inner wall of the regenerator. The working gas passes through the space between the plurality of plate members arranged radially, and when moving from the compression space to the expansion space, heat is absorbed and accumulated in the plate members and the base, and from the expansion space to the compression space. The heat accumulated during the movement is taken from the plate-like member and the base to cool the heat storage body.

According to a third aspect of the present invention, in the regenerator of the Stirling engine according to the first or second aspect, the thickness of the plate-like member is the same at the root and at the tip or as the tip becomes thinner. It is characterized by: According to this configuration, the thickness of the plate member is constant or becomes thinner toward the outer periphery of the regenerator. And the movement of the heat stored in the heat storage body in the outer peripheral direction of the regenerator is suppressed.

According to a fourth aspect of the present invention, in the regenerator of a Stirling engine according to any one of the first to third aspects, a groove parallel to a traveling direction of the working gas is formed in a side wall of the plate-like member. Alternatively, a projection is formed.

According to this configuration, the heat storage body is inserted into the regenerator so that the plate-like base is deformed into a ring shape so that the longitudinal direction of the plate-like member is along the traveling direction of the working gas. The working gas passes through the space between the plurality of plate members arranged radially,
When moving from the compression space to the expansion space, heat is absorbed and accumulated in the plate-like member and the base via the side wall surface, the groove or the projection, and when moving from the expansion space to the compression space, the side wall surface, the groove or The heat accumulated through the projections is taken from the plate member and the base to cool the heat storage body.

According to a fifth aspect of the present invention, in the regenerator of the Stirling engine according to any one of the first to fourth aspects, the heat accumulators are arranged in series and have different first and second materials. It is characterized by comprising two heat storage bodies.

According to this structure, the first and second regenerators are arranged in series in the regenerator so that the plate-like base member is deformed into a ring shape so that the longitudinal direction of the plate-like member is along the traveling direction of the working gas. Is inserted into. The working gas passes through a space between the plurality of plate members of the first and second heat storage units arranged radially, and absorbs heat in the plate member and the base when moving from the compression space to the expansion space. The accumulated heat is removed from the plate member and the base when moving from the expansion space to the compression space to cool the first and second heat storage bodies.

According to a sixth aspect of the present invention, in the regenerator of the Stirling engine according to the fifth aspect, the first heat accumulator is formed of a metal material and the second heat accumulator is formed of a resin material. And the first heat storage element is arranged on the compression space side.

According to this configuration, the first and second heat accumulators are formed in series in the regenerator such that the plate-like base is deformed into a ring shape so that the longitudinal direction of the plate-like member is along the traveling direction of the working gas. Is inserted into. When the working gas passes from the compression space to the expansion space through the space between the plurality of plate members arranged radially, the working gas is transferred to the plate member and the base of the first heat storage body made of a metal material. After the heat is absorbed and accumulated, the heat is absorbed and accumulated in the plate member and the base of the second heat storage body made of a resin material. Then, when moving from the expansion space to the compression space, after removing heat from the plate member of the second heat storage body made of a resin material and the base, the plate member of the first heat storage body made of a metal material And take heat from the base.

According to a seventh aspect of the present invention, in the regenerator of the Stirling engine according to any one of the first to fourth aspects, the heat accumulators are arranged in series and a distance between the plate-like members is reduced. Consisting of different first and second heat storages,
It is characterized in that the one with the larger interval is arranged on the compression space side.

According to this configuration, the first and second heat storage bodies are formed in series in the regenerator so that the plate-like base member is deformed into a ring shape so that the longitudinal direction of the plate-like member is along the traveling direction of the working gas. Is inserted into. When the working gas moves from the compression space to the expansion space through the space between the plurality of radially arranged plate-like members, heat is applied to the plate-like member and the base of the first heat storage body having a large interval. Is absorbed and accumulated, the heat is absorbed and accumulated in the plate-like member and the base at a small interval of the second heat storage body. Then, when moving from the expansion space to the compression space, heat is taken from the plate member and the base having a small interval between the second heat accumulators, and then the plate member and the base member having a large interval between the first heat accumulators are removed. Take away heat from the platform.

According to an eighth aspect of the present invention, in the regenerator of the Stirling engine according to any one of the first to seventh aspects, the surface of the heat storage body is coated with a heat storage material. I have.

According to this configuration, the heat storage body is inserted into the regenerator so that the longitudinal direction of the plate-like member follows the working gas traveling direction by deforming the flat base into a ring shape. The working gas passes through the space between the plurality of plate members arranged radially,
The heat is absorbed and accumulated in the plate-like member and the base through the heat storage material coated when moving from the compression space to the expansion space, and the heat is stored through the coated heat storage material when moving from the expansion space to the compression space. The heat is removed from the plate member and the base. Here, the heat storage material refers to an inorganic material, a black heat-resistant paint, a selective absorption film whose emissivity and absorptance are optimally adjusted, and the like.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. 1 and 2 are a schematic sectional view and a schematic perspective view showing a regenerator of a Stirling engine according to an embodiment of the present invention. A regenerator 11 is formed by disposing a heat storage body 21 in a passage 12 formed between the inner cylinder 2 and the outer cylinder 3 of the Stirling engine shown in FIG.

The heat storage body 21 is provided on the outer wall 3 d of the inner cylinder 2.
A large number of fins 21b on a base 21a forming an annular shape along
Are formed radially, and each fin 21b,.
Between them is a fluid passage 12 'through which the working gas passes. Then, when the working gas moves from the compression space 9 to the expansion space 10 (see FIG. 7) through the fluid passage 12 ', the base 21
a and the heat held by the working gas in contact with the fins 21b is accumulated in the heat storage body 21, and the heat accumulated in contact with the base 21a and the fins 21b when moving from the expansion space 10 to the compression space 9 is reduced. Absorb from the heat storage body 21.

As shown in the sectional view and the perspective view of FIG. 3 and FIG. 4, such a heat storage body 21 has a comb-like shape in which plate-like fins 21b are erected on a plate-like base 21a at equal intervals. It can be obtained by extruding and forming the base 21a into an annular shape as shown in FIG.

The thickness t of the fin 21a is 0.1 mm to 1
When the distance w between the fins 21b is in the range of 0.1 mm to 2 mm, a large contact area with the working gas can be ensured, the pressure loss can be suppressed, and high heat storage efficiency can be obtained. Further, it is desirable that the thickness t and the interval w of the fins 21a are in the range of 0.1 mm to 0.3 mm, because the heat storage efficiency can be further improved.

Since the heat storage body 21 can be formed by extruding a metal material or a resin material, thin fins 21b can be easily formed at equal intervals and in parallel with high precision. Also, the desired length L can be easily obtained by cutting the extruded long heat storage body 21. Therefore, the manufacturing cost of the regenerator 11 can be reduced, and
The pressure of the working gas becomes uniform both in the cross section and in the length direction, so that the regenerator 11 with little variation without individual difference in the flow rate of the working gas can be obtained.

Further, the cross-sectional shape of the fin 21b can be adjusted by making the thickness t of the root portion and the tip portion the same as shown in FIG. 3 described above, or by making the tip portion thinner as shown in FIG. Since the heat storage bodies 21 are radially installed in the heat generator 11, the density of the heat storage bodies 21 becomes smaller toward the outer periphery in the regenerator 11. Therefore, heat leak radiating heat from the outer cylinder 2 to the atmosphere can be reduced, and the heat storage efficiency can be further improved.

In the present embodiment, the height h of the heat storage body 21 including the base 21a is determined by the inner diameter R1 of the outer cylinder 2 (see FIG. 1) and the inner diameter R2 of the base 21a when formed into an annular shape (this embodiment). In this case, the fin 21b is in contact with the inner wall 2a of the outer cylinder 2 and is bent in an arc shape to be installed in the regenerator 11 as shown in FIG. I have.

In this manner, the fin 21b having a large surface area can be installed in the outer cylinder 2 having a limited diameter, and the contact area of the fin 21b with the working gas is increased to improve the heat storage efficiency. Can be. Further, FIG.
As shown in the sectional view of FIG.
Providing the protrusions 1c and the protrusions 21d is preferable because the contact area with the working gas becomes larger.

The heat storage body 21 may be coated with a heat storage material such as an inorganic material having a large specific heat, a black heat-resistant paint having a small emissivity, or a selective absorption film whose emissivity and absorptance are optimally adjusted. The heat storage efficiency can be improved by improving the heat capacity.

Next, as described above, since the heat storage body 21 can be easily formed to a desired length L, the regenerator 1
It is easy to arrange two types of heat storage bodies 21 in a desired length in one.

The compression space 9 (FIG. 7)
When a heat storage body made of a metal material is arranged on the side of the regenerator 11 and a heat storage body made of a resin material is arranged on the side of the expansion space 10 of the regenerator 11 where the temperature is low, thermal deformation when the resin material is used on the high temperature side is prevented. The heat storage efficiency can be improved by a resin material having a higher specific heat than a metal material. The metal material and the resin material are desirably stainless steel, Hastelloy, copper, aluminum, etc. and polyester, nylon, urethane, etc. having a large specific heat. You may.

Further, the compression space 9 of the regenerator 11 where the temperature becomes high
The distance w (see FIG. 3) between the heat storage fins 21b arranged on the side of the heat storage body 21b arranged on the side of the expansion space 10
May be larger than the interval w. This way,
It is possible to prevent an increase in pressure loss caused by an increase in viscosity of the working gas such as helium due to a high temperature, thereby improving heat storage efficiency.

[0039]

According to the first aspect of the present invention, since the heat storage body can be formed by extrusion molding, thin fins can be easily formed at equal intervals and in parallel with high precision. Also, the desired length can be easily obtained by cutting a long heat storage body that has been extruded. Therefore, the manufacturing cost of the regenerator can be reduced, and the pressure of the working gas in the cross section and the length direction of the regenerator becomes uniform, and the regenerator has little variation without causing individual differences in the flow rate of the working gas. Can be obtained.

According to the second aspect of the present invention, since the fins are in contact with the inner wall of the outer cylinder and are formed to have a high height so as to be bent in an arc and to be installed in the regenerator, the fin has a limited outer diameter. Fins having a large surface area can be installed in the vessel, and the contact area with the working gas increases, so that the heat storage efficiency can be improved.

According to the third aspect of the present invention, the heat storage bodies are radially installed in the regenerator by making the cross-sectional shape of the fins equal in thickness at the root portion and at the tip portion or by making the tip portion thinner. For this reason, the density of the heat storage body becomes smaller toward the outer periphery in the regenerator. Therefore, it is possible to reduce heat leak radiating heat from the outer wall of the regenerator to the atmosphere, and to improve heat storage efficiency.

According to the fourth aspect of the present invention, when grooves or projections are provided on the side walls of the fins, the contact area between the heat storage body and the working gas becomes larger, so that the heat storage efficiency can be improved.

According to the fifth aspect of the present invention, a heat storage body made of a heat-resistant material is disposed on the compression space side of the regenerator at a high temperature, and a heat storage material made of a material having a large specific heat is placed on the expansion space side of the regenerator at a low temperature. When it is arranged, thermal deformation on the high temperature side can be prevented, and the heat storage efficiency can be improved with a material having a large specific heat.

According to the sixth aspect of the present invention, the heat storage body made of a metal material is arranged on the compression space side of the regenerator which becomes high in temperature, and the heat storage body made of resin material is arranged on the expansion space side of the regenerator which becomes low in temperature. In addition, it is possible to prevent thermal deformation when a resin material is used on the high temperature side, and it is possible to improve the heat storage efficiency by using a resin material having a higher specific heat than a metal material.

According to the seventh aspect of the present invention, the interval between the fins of the heat storage element disposed on the compression space side of the regenerator, which is heated to a high temperature, is made larger than the distance between the fins of the heat storage element disposed on the expansion space side, such as helium. In this case, it is possible to prevent an increase in pressure loss caused by an increase in the viscosity of the working gas at a high temperature, thereby improving the heat storage efficiency.

According to the invention of claim 8, the surface of the heat storage body is made of a heat storage material such as an inorganic material having a large specific heat, a black heat-resistant paint having a small emissivity, or a selective absorption film whose emissivity and absorptance are optimally adjusted. Because of the coating, the heat capacity can be improved and the heat storage efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a regenerator according to the present invention.

FIG. 2 is a schematic perspective view of a regenerator according to the present invention.

FIG. 3 is a schematic cross-sectional view of a heat storage body disposed in a regenerator according to the present invention.

FIG. 4 is a schematic perspective view of a heat storage body disposed in a regenerator according to the present invention.

FIG. 5 is a schematic cross-sectional view of another embodiment of the heat storage body disposed in the regenerator according to the present invention.

FIG. 6 is a schematic sectional view of still another embodiment of the heat storage body disposed in the regenerator according to the present invention.

FIG. 7 is a schematic sectional view showing a conventional Stirling refrigerator.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 cold head 2 outer cylinder 3 inner cylinder 4 displacer 5 compression piston 7 linear motor 9 compression space 10 expansion space 11 regenerator 12 passage 21 heat storage body 21a base 21b fin

Claims (8)

[Claims] 1. A heat storage element disposed on a passage connecting a compression space and an expansion space of a Stirling engine to accumulate heat held by a working gas reciprocating in the passage and to accumulate the accumulated heat. In the regenerator of the Stirling engine that supplies the heat storage body formed by standing a plurality of plate-like members at equal intervals on a flat base, the plate-like members are radially directed outward. A regenerator for a Stirling engine, wherein the base is arranged in an annular shape. 2. A regenerator for a Stirling engine according to claim 1, wherein a tip of said plate-shaped member is in contact with said inner wall of said passage, and a cross-sectional shape of said plate-shaped member is curved. 3. The regenerator for a Stirling engine according to claim 1, wherein the thickness of the plate-like member is the same at the root and at the tip or the tip is thinner. 4. The regenerator for a Stirling engine according to claim 1, wherein a groove or a protrusion is formed on a side wall of the plate-shaped member in parallel with a traveling direction of the working gas. 5. A regenerator for a Stirling engine according to claim 1, wherein said heat storage elements are composed of first and second heat storage elements having different materials and arranged in series. 6. The first heat storage body is formed of a metal material,
6. The heat storage element is formed of a resin material, and the first heat storage element is disposed on the compression space side.
A regenerator for a Stirling engine according to the above. 7. The heat storage body is composed of first and second heat storage bodies arranged in series and having different intervals between the plate-like members, and the wider one is arranged on the compression space side. A regenerator for a Stirling engine according to any one of claims 1 to 4. 8. The heat storage material according to claim 1, wherein a surface of the heat storage body is coated with a heat storage material.
A regenerator for a Stirling engine according to any of the preceding claims.