US20150211770A1

US20150211770A1 - Stirling Cycle Device

Info

Publication number: US20150211770A1
Application number: US14/604,143
Authority: US
Inventors: Rong Wang
Original assignee: NINGBO RONGJIETE MACHINERY MANUFACTURING Co Ltd
Current assignee: NINGBO RONGJIETE MACHINERY MANUFACTURING Co Ltd
Priority date: 2014-01-24
Filing date: 2015-01-23
Publication date: 2015-07-30

Abstract

A Stirling cycle device includes a housing with an inner wall, and a regenerator attached to the inner wall of the housing, wherein the regenerator, made of wool or chemical fiber, is composed of two, three, or four sub-regenerators and the height of the regenerator is independent on number of sub-regenerators. As the regenerator is made of wool or chemical fiber, which may ensure a sufficient permeability and heat storage performance; as the regenerator is composed of a plurality of sub-regenerators, clearances may be formed between each two sub-regenerators, and as the clearances have a density less than the surrounding sub-regenerators, these clearances may be used for energy storage, heat insulation and air circulation. Consequently, the refrigerating performance of the cycle device is improved as the efficiency of pre-cooling and pre-heating of the working gas in the regenerator is improved.

Description

RELATED APPLICATIONS

This application claims the benefit of Chinese Invention Application 201410034789.2, filed on Jan. 24, 2014 and Chinese Invention Application 201410035215.7, filed on Jan. 24, 2014. The specifications of both applications are incorporated here by this reference.

FIELD OF THE INVENTION

The present invention relates to a Stirling cycle device for cooling or heating or the like.

DESCRIPTION OF THE PRIOR ART

A Stirling cycle device is a device in which a displacer and a piston are coaxially provided inside an air cylinder so that when in operation, the reciprocating motion of the piston drives the gas to expand or compress periodically in order to generate cold (or heat). A compression chamber is formed between one end of the displacer and the piston while an expansion chamber is formed at the other end of the displacer, a regenerator is disposed between the compression chamber and the expansion chamber, and the two chambers are communicated to each other through the regenerator to form a closed loop inside the cycle device. Heat absorbers (at the end where the expansion chamber is formed) and heat sinks (at the end where the compression chamber is formed) are provided at two ends of the regenerator, each heat sink having cooling fins which facilitate heat exchange with the outside air. The piston is driven to allow the gas inside the compressed chamber to be compressed and fed into the regenerator and further conveyed into the expansion chamber, with heat of the gas being accumulated by the regenerator, hereafter, the compressed high-pressure working gas expands inside the expansion chamber. Then, the temperature falls, the piston resets, and the working gas returns back to the compression chamber through the regenerator again. The heat accumulated inside the regenerator is imparted to the working gas so that the temperature of the working gas rises. By repeated cycles, the temperature of the heat absorbers gradually becomes low, to be extremely low. The principle of heating is similar.
In the prior art, the regenerator is usually made of resin. Such a regenerator, however, is complicated in manufacturing, and the refrigerating efficiency is decreased due to the poor permeability, which hinders the circulation of cold air and hot air in some extent, of the resin. For this reason, regenerators made of other materials have been disclosed in the prior art. For example, a Stirling refrigerator disclosed in a Chinese Patent Application, the application No. 00817515.2, the regenerator is a matrix of fine wire or a ring-shaped gap formed by wounding foil. However, due to the large coefficient of heat conductivity, quick heat radiation and poor energy storage performance of the wire, both the pre-cooling of hot air when it passes through the regenerator and the pre-heating of cold air when it passes through the regenerator are insufficient. As a result, the refrigerating efficiency is also decreased.
In addition, to improve the heat exchange efficiency of the cooling fins, the cooling fins require a large contact area and a large weight. However, the existing cooling fins, for example, those used in a heat exchanger for a Stirling refrigerator as disclosed in a Chinese Patent Application (Application No. 01815042.X), are integrally formed an annular corrugated fin that is produced by forming a sheet material, corrugated so as to have a large number of grooves, into a cylindrical shape with the grooves parallel to an axis of the cylindrical shape. When it is intended to ensure smooth circulation of gas, the sides of the grooves of the corrugated fin have a small contact area (or even no contact), i.e., large opening of the V-grooves, thereby resulting in low heat conductivity; and when it is intended to improve the heat conductivity, the cooling fins should have a large contact area (i.e., large cooling area), for this purpose, the grooves are squeezed, the V-shape of the grooves is compressed and the opening of the V-shape is reduced (or even closed), consequently, the circulation of gas is hindered. That is, the existing folding manner is unable to ensure both the smooth circulation of gas and the improved heat conductivity, and thus unable to realize high heat exchange efficiency.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a Stirling cycle device with improved refrigerating efficiency.
For achieving the above stated object, a Stirling cycle device comprises: a housing with an inner wall; a regenerator attached to the inner wall of the housing, the regenerator having a thickness, a top, and a bottom, wherein the regenerator, made of wool or chemical fiber, is composed of two, three, or four sub-regenerators and the height of the regenerator is independent on number of sub-regenerators.
The regenerator has a height between 34.5 mm and 36 mm, a wall thickness between 4.8 mm and 5 mm, and an outer diameter between 36.6 mm and 36.8 mm. The permeability and the heat insulation may be best balanced by controlling the overall weight of the regenerator, and the refrigerating efficiency is thus improved.
As a preference, a first cooling element is disposed on the top and a second cooling element is disposed on the bottom of the regenerator, two cooling elements are attached to the housing, each cooling element is formed with a heat dissipation element folded in a continuous wave fashion, and the heat dissipation element has a start and an end, the start and the end of the heat dissipation element attached to each other forming a cylinder, the cylinder has a transverse section with an inner side and an outer side, multiple arch units are formed on the inner side and the outer side of the transverse section, each two adjacent arch units are attached closely;
multiple pores are formed in the heat dissipation element, the pores are distributed in an upper row and a lower row, and the pores in the upper row and the pores in the lower row are interlaced.
Such a folding manner of compact compression of the cooling elements 3 that each cooling element has large contact area and large weight; furthermore, the heat dissipation element is compressed leftward and rightward, upward and downward to form more pores and contact area, thereby the optimum gas permeability and heat conductivity can be achieved.
As a preference, each of the first cooling element and the second cooling element is attached to the housing through a positioned ring.
As a preference, each heat dissipation element is made of copper or aluminum with high heat conductivity.
As a preference, the transverse section of the cylinder of each heat dissipation element has a perimeter between 98 mm and 98.5 mm, the annular thickness of the transverse section is between 4.6 mm and 4.7 mm, and the height of the cylinder is between 6.8 mm and 7 mm.
As a preference, each of the first cooling element and the second cooling element has multiple pores with a porosity between 10% and 90%.
Compared with the prior art, in the present invention,
first, as the regenerator 2 is made of wool or chemical fiber, which may ensure a sufficient permeability and heat storage performance;
second, as the regenerator is composed of a plurality of sub-regenerators, clearances may be formed between each two sub-regenerators, and as the clearances have a density less than the surrounding sub-regenerators, these clearances may be used for energy storage, heat insulation and air circulation. Consequently, the refrigerating performance of the cycle device is improved as the efficiency of pre-cooling and pre-heating of the working gas in the regenerator is improved;
third, each cooling element is formed with a heat dissipation element folded in a continuous wave fashion, so that more pores and contact area are formed, and the optimum gas permeability and heat conductivity can be achieved, thereby improve heat conductivity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a Stirling cycle device in accordance with an embodiment of the present invention;

FIG. 2 is a sectional view of a regenerator in accordance with the embodiment of the present invention;

FIG. 3 is a view of a heat dissipation element after folded in a continuous wave fashion but not yet form a cylinder in accordance with the embodiment of the present invention;

FIG. 4 is perspective view of a cooling element (a cylinder) in accordance with the embodiment of the present invention;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

To enable a further understanding of the innovative and technological content of the invention herein, refer to the detailed description of the invention and the accompanying drawings below:
Referring to FIG. 1 and FIG. 2, a Stirling cycle device comprises a housing 1 with an inner wall, a regenerator 2 with a thickness, a top, and a bottom, and a first cooling element 3 is disposed on the top and a second cooling element 3 is disposed on the bottom of the regenerator 2, a displacer 4 is disposed in the regenerator 2; the remaining configuration of the cycle device may be employed from the prior art and will not be repeated here.
The regenerator 2, the two cooling elements 3 and displacer 4 are disposed inside the housing 1, the regenerator 2 are cylindrical, the regenerator 2 and the two cooling elements 3 are attached to the inner wall of the housing 1, each of two cooling elements 3 is a cylinder and is attached to the housing 1 through a positioned ring 31.
In the present invention, the regenerator 2 is made of wool or chemical fiber, which is low in cost and simple in manufacturing process; furthermore, as wool or chemical fiber may ensure a sufficient permeability, the circulation of gas is smooth. Additionally, as the coefficient of heat conductivity of wool or chemical fiber is far below that of wire, good heat storage performance is achieved while ensuring good permeability. Hence, the refrigerating efficiency of the Stirling cycle can be improved effectively.
In order to further improve the refrigerating efficiency, the regenerator 2 is composed of two, three, or four sub-regenerators and the height of the regenerator 2 is independent on number of sub-regenerators. That is, when the regenerator 2 is composed of two sub-regenerators, the height of the regenerator 2 is between 34.5 mm and 36 mm, each sub-regenerator has a height between 17.25 mm and 18 mm, and a wall thickness between 4.8 mm and 5 mm, and an outer diameter between 36.6 mm and 36.8 mm. At this time, the sizes of the wall thickness and the outer diameter of each sub-regenerator are the same. The regenerator 2 is composed of three or four sub-regenerators are similar.
Therefore, the weight of the regenerator 2 may be controlled to best balance the permeability and the heat insulation, and the refrigerating efficiency is thus improved. Furthermore, as the regenerator is composed of a plurality of sub-regenerators, clearances may be formed between each two sub-regenerators, and as the clearances have a density less than the surrounding sub-regenerators, these clearances may be used for energy storage, heat insulation and air circulation. Consequently, cold air, when it flows through the regenerator 2 into the compression chamber, may be sufficiently pre-heated by heat stored inside the clearances; and hot air, when it flows through the regenerator 2 into expansion chamber, may be sufficiently pre-cooled by cold stored inside the clearances. The refrigerating performance of the cycle device is improved as the efficiency of pre-cooling and pre-heating of the working gas in the regenerator 2 is improved.
Referring to FIG. 3 and FIG. 4, views of the cooling element 3 are shown. Each cooling element 3 is formed with a heat dissipation element folded in a continuous wave fashion, and the heat dissipation element has a start and an end, the start and the end of the heat dissipation element attached to each other forming a cylinder(the width of the heat dissipation element serves as the height of the cylinder), the cylinder has a transverse section with an inner side(which is close to the central hole of the cylinder) and an outer side(which is away from the central hole of the cylinder), multiple arch units 32 are formed on the inner side and the outer side of the transverse section, each two adjacent arch units 32 are attached closely, so that the surface of the inner side and the outer side of the cylinder are in wave.
Multiple pores 33 are formed in the heat dissipation element 3, the pores 33 are distributed in an upper row and a lower row, and the pores 33 in the upper row and the pores in the lower row are interlaced. Each of the first cooling element 3 and the second cooling element 3 has multiple pores 33 with a porosity between 10% and 90%.
Each heat dissipation element is made of copper or aluminum with high heat conductivity. As shown in FIG. 4, the transverse section of the cylinder of each heat dissipation element has a perimeter L (approximately equal to the length of the heat dissipation element after folded in a continuous wave fashion but not yet form a cylinder) between 98 mm and 98.5 mm, the annular thickness T of the transverse section is between 4.6 mm and 4.7 mm, and the height H of the cylinder is between 6.8 mm and 7 mm.
Such a folding manner of compact compression of the cooling elements 3 that each cooling element has large contact area and large weight; furthermore, the heat dissipation element is compressed leftward and rightward, upward and downward to form more pores and contact area, thereby the optimum gas permeability and heat conductivity can be achieved. That is, during the folding and compression, the cooling elements have enough pores to realize smooth circulation of gas, and also have enough contact area(each two adjacent arch units 32 with the pores interlaced distributed in an upper row or a lower row always attach closely, so that the cooling elements always maintain pores and contact surfaces during the folding and compression) to improve heat conductivity.

Claims

1. A Stirling cycle device, comprising:

a housing with an inner wall;

a regenerator attached to the inner wall of the housing, the regenerator having a thickness, a top, and a bottom,

wherein the regenerator, made of wool or chemical fiber, is composed of two, three, or four sub-regenerators and the height of the regenerator is independent on number of sub-regenerators.

2. The Stirling cycle device of claim 1, wherein the regenerator has a height between 34.5 mm and 36 mm, a wall thickness between 4.8 mm and 5 mm, and an outer diameter between 36.6 mm and 36.8 mm.

3. The Stirling cycle device of claim 1, wherein a first cooling element is disposed on the top and a second cooling element is disposed on the bottom of the regenerator, two cooling elements are attached to the housing, each cooling element is formed with a heat dissipation element folded in a continuous wave fashion, and the heat dissipation element has a start and an end, the start and the end of the heat dissipation element attached to each other forming a cylinder, the cylinder has a transverse section with an inner side and an outer side, multiple arch units are formed on the inner side and the outer side of the transverse section, each two adjacent arch units are attached closely;

multiple pores are formed in the heat dissipation element, the pores are distributed in an upper row and a lower row, and the pores in the upper row and the pores in the lower row are interlaced.

4. The Stirling cycle device of claim 3, wherein each of the first cooling element and the second cooling element is attached to the housing through a positioned ring.

5. The Stirling cycle device of claim 3, wherein each heat dissipation element is made of copper or aluminum with high heat conductivity.

6. The Stirling cycle device of claim 3, wherein the transverse section of the cylinder of each heat dissipation element has a perimeter between 98 mm and 98.5 mm, the annular thickness of the transverse section is between 4.6 mm and 4.7 mm, and the height of the cylinder is between 6.8 mm and 7 mm.

7. The Stirling cycle device of claim 3, wherein each of the first cooling element and the second cooling element has multiple pores with a porosity between 10% and 90%.