JP2007518952A - Refrigerating machine regenerator - Google Patents

Abstract

  The present invention relates to a regenerator for a refrigerator equipped with a heat storage material having uniform air permeability and improved heat transfer performance. A large number of mats are separated from a base mat formed by vacuum-sintering a random wire. A plurality of mats separated from the base mat are inserted into the housing in a row. According to the present invention, since the plurality of mats are inserted into the housing in a line, uniform ventilation is performed throughout the housing. The boundary layer between adjacent mats minimizes heat transfer loss and significantly improves the cooling performance of the refrigerator.

Description

  The present invention relates to a refrigerator, and more particularly, to a regenerator for a refrigerator provided with a heat storage material having uniform air permeability and improved heat transfer performance.

  Generally, a refrigerator is a device that generates a refrigeration output through a process such as compression-expansion by a working fluid such as helium or hydrogen. Such refrigerators are used for freezing small electrical appliances and superconductors to cryogenic temperatures.

  As the refrigerator, a heat regeneration type such as a Stirling refrigerator or a GM refrigerator is mainly used. In such a refrigerator, the reliability is improved by reducing the operating speed, changing the shape of the sealing material that generates friction, or eliminating the moving part.

  There is a need for development of a highly reliable cryogenic refrigerator that does not require maintenance for a long period of time. However, a non-lubricated pulse tube refrigerator that reflects such a demand is required. It is. In this pulse tube refrigerator, when a pressure is changed by periodically injecting a gas having a constant temperature into one closed tube, a very large temperature gradient can be obtained when there are few turbulent components in the gas flow. It is a device that realizes cryogenic refrigeration on the open side of the tube using the principle.

  FIG. 1 shows a refrigerator according to the prior art. As shown in the figure, the refrigerator 1 is roughly divided into a drive unit 100, a heat dissipation unit 200, and a freezing unit 300.

  The driving unit 100 compresses the refrigerant gas into a high-temperature and high-pressure state by the linear reciprocating motion of the piston 140 due to the electromagnetic interaction of the linear motor 130. Such a drive unit 100 includes a shell tube 120, a linear motor 130, a piston 140, a cylinder 150, a leaf spring 160 and a spring cradle 170.

  The shell tube 120 has a predetermined internal space and is engaged and fixed to the frame 110 so as to be concentric with the inner and outer heat radiating portions 210 and 220 in which the displacer 310 is inserted. The linear motor 130 includes a stator 130a and an armature 130b, and is attached to the shell tube 120. The piston 140 is fixed to one side of the armature 130b of the linear motor 130, and linearly reciprocates by the electromagnetic interaction of the linear motor 130. The cylinder 150 is engaged with the frame 100 at the center inside the frame 110 so that the linear reciprocating motion of the piston 140 inserted concentrically with the inner heat radiating part 210 can be transmitted horizontally to the displacer 310. Fixed. The leaf spring 160 is fixedly supported on one side of the displacer rod 320 such that the position of the displacer rod 320 inserted into the piston 140 is concentric with the piston 140 and the inner heat radiating portion 210. The spring cradle 170 is fixed to the shell tube 120 on one side to fix the leaf spring 160, and the leaf spring 160 is engaged and fixed to the other side.

  The heat dissipating part 200 is fixed to the frame 110 on the outer periphery of the displacer 310, and an inner heat dissipating part 210 that absorbs heat of the refrigerant gas compressed into a high temperature and high pressure state by the piston 140, and an outer circumferential surface of the inner heat dissipating part 210. The outer heat radiating section 220 is fixed and radiates the heat of the refrigerant gas transmitted from the inner heat radiating section 210 to the outside of the refrigerator.

  The refrigeration unit 300 includes a displacer 310, a regenerator 330, and a cold side unit 350. The displacer 310 is integrally formed with the displacer rod 320, and is a leaf spring that is inserted into the inner heat radiating portion 210 and fixed to one side of the displacer rod 320 through compression of refrigerant gas added from the piston 140. A linear reciprocating motion is performed within the 160 elastic deformation range. The regenerator 330 is coupled to the displacer 310 and stores the scorching heat of the high-temperature and high-pressure refrigerant gas compressed and flowed into the displacer 310 by the piston 140, and then is expanded in an expansion space later. The temperature of the refrigerant gas is compensated for heat transfer to the refrigerant gas in a certain high temperature state. The cold side portion 350 is provided at a position spaced apart from the regenerator 330 and the expansion space at a constant interval, and the refrigerant gas penetrating the regenerator 330 is thermally changed to a low temperature state while expanding in the expansion space. To exchange heat with the outside.

The operational relationship of the refrigerator configured as described above will be described.
First, the linear motor 130, that is, the armature 130b linearly moves due to electromagnetic interaction between the stator 130a and the armature 130b, so that the piston 140 fixed to one side of the armature 130b also moves linearly. . At this time, the refrigerant gas such as helium or hydrogen filled in the compression space is compressed by the linear motion of the piston 140.

  A part of the refrigerant gas compressed in this way is discharged to the outside of the refrigerator 10 through the heat radiating unit 200, and the other part flows into the regenerator 330 through the displacer 310. At this time, the displacer 310 moves linearly toward the expansion space by the compressed refrigerant gas.

  The compressed refrigerant gas that has flowed into the regenerator 330 is thermally conducted so as to store thermal energy while passing through the regenerator 330, and then flows into the expansion space. At this time, the pressure applied to the piston 140 decreases. As a result, the displacer 310 linearly reciprocates toward the compression space.

  Next, the refrigerant gas flowing into the expansion space becomes a cryogenic state by the expansion action, and the low-temperature refrigerant gas expanded as described above is transferred with the stored thermal energy while passing through the regenerator 330 again. It flows into the compression space.

  Thus, the refrigerator 1 is cooled by repeating the cycle of the operation process as described above.

  On the other hand, as shown in FIG. 2, the regenerator 330 coupled to the displacer 310 includes a housing 340 that is concentrically engaged with the cylinder of the displacer 310, and a heat storage material 344 that is inserted into the housing 340. And an end cap 348 attached to the front end of the housing 340.

  The heat storage material 344 performs heat exchange in contact with the refrigerant gas, thereby receiving, storing, and returning energy from the refrigerant gas. Therefore, the heat storage material 344 has a large heat exchange area and specific heat, and a small heat conduction coefficient. It is preferable to use a material.

  In view of such a situation, the heat storage material 344 is configured as a fine powder, small sphere, or random wire type. In particular, each of these types is composed of different materials depending on the temperature range in which the refrigerator is used. In general, a regenerator for a refrigerator that is used for cryogenic cooling at about 77 ° K often uses a random wire type heat storage material made of stainless steel.

  The random wire type heat storage material has a form in which fine wires are hardened. Therefore, in order to insert a random wire type heat storage material into the regenerator, it is molded into a fixed shape with a mold and then inserted into the housing due to structural characteristics.

  However, in the conventional regenerator to which the random wire type heat storage material is applied, there is a problem that it takes cost and time to form a random wire that is randomly formed into a certain shape. Further, since the random wire is in a solidified form, heat transfer is easily performed, and the efficiency of the regenerator is reduced.

  Further, in the process of inserting a random wire type heat storage material into the housing of the regenerator, the heat storage material is not pressure-bonded at the same interval over the entire portion in the housing. That is, a random wire of a certain form that has been previously inserted into the housing is pushed by a random wire that is inserted later, and the rear part in the housing is inserted with the random wire being overcrowded and the front part in the housing. The mouth becomes dense. Accordingly, there is a problem that the performance of the refrigerator is deteriorated because uniform air permeability is not ensured over the entire portion of the housing.

  Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to store heat in which a large number of mats made by vacuum sintering are packed in a row in a housing. It is providing the regenerator for refrigerators provided with the material.

  According to a preferred embodiment of the present invention for achieving the above object, a housing having a predetermined space inside and engaged with a displacer, and a base provided in advance in the housing A heat storage material into which a number of mats provided from the mat are inserted, and an end cap attached to the tip of the housing.

  The plurality of mats are formed of a random wire material and are filled in a row in the housing.

  The thickness of the mat or the number of mats inserted into the housing varies depending on the heat transfer coefficient and / or air permeability in the housing.

  According to another preferred embodiment of the present invention, the heat storage material of the regenerator for the refrigerator is a number of mats filled in the housing.

  The plurality of mats are made of random wires made of the same material.

  According to still another preferred embodiment of the present invention, a method of forming a heat storage material for a regenerator for a refrigerator includes a step of vacuum sintering a prebonded random wire to form a base mat; A step of separating a number of mats having a certain shape by punching, and a step of inserting the separated number of mats into a housing in a row.

  The thickness of the base mat varies depending on the degree of pressure bonding in the pressure bonding process.

  At least one mat is separated from the base mat.

  The number of mats inserted into the housing varies depending on the degree of adhesion between the mats.

  The shape of the fixed form mat is one of a circle, a rectangle, and a polygon.

  As described above, according to the regenerator for a refrigerator of the present invention, a large number of mats are filled in the housing in a row, thereby maintaining the air permeability uniformly throughout the housing and the cooling performance of the refrigerator. Will improve.

  In addition, since a certain boundary layer is formed between a large number of mats, heat transfer can be delayed and heat transfer loss can be further reduced.

  According to the method for forming a heat storage material for a regenerator for a refrigerator according to the present invention, a large number of mats can be easily separated from a base mat formed by a vacuum sintering method at a time, so that the cost can be significantly reduced. it can.

  Moreover, many mats can be manufactured according to the form of a housing, and the application range of the regenerator for refrigerators can be improved greatly.

  Furthermore, the thickness of the mat and the number of mats inserted into the housing can be adjusted to reflect the heat transfer coefficient and / or air permeability in the housing, and the optimum heat transfer coefficient and air permeability are always ensured. There is an effect.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 3 shows a regenerator for a refrigerator according to a preferred embodiment of the present invention. As shown in the figure, the regenerator for a refrigerator of the present invention has a predetermined space inside, a housing 42 engaged with the displacer 32, a heat storage material 44 inserted into the housing 42, The end cap 46 is attached to the tip of the housing 42.

  Here, the heat storage material 44 is composed of a number of mats processed into a certain form. A number of mats are made of random wire material and are sequentially stacked in a row in the housing 42. A number of mats are provided in advance so as to match the diameter in the housing 42 by punching or the like.

  The thickness of the mat can vary depending on the thermal conductivity and / or air permeability within the housing 42. That is, when the thermal conductivity and / or air permeability is poor, a thin mat is inserted into the housing. Also, the number of mats inserted into the housing can vary depending on the heat transfer coefficient and / or air permeability within the housing. That is, if the thermal conductivity and / or air permeability is poor, a smaller amount of mat is inserted into the housing. In this way, the heat transfer rate and / or air permeability within the housing can be adjusted using the thickness of the mat and the number of mats, so that the optimum heat transfer rate and / or air permeability is always maintained within the housing. can do.

  Conventionally, when a random wire that is simply formed in a certain shape is inserted into a housing, the random wire that has been inserted first is pushed by the random wire that is inserted later, and the entire inside of the housing has uniform air permeability. Is not secured.

  However, according to the present invention, since a large number of mats are filled in the housing 42 as an example, there is no possibility that the mat inserted earlier is pushed by the mat inserted later. Can be kept uniform.

Hereinafter, the formation method of the heat storage material with which the regenerator for refrigerators is equipped is demonstrated.
FIG. 4 is a flowchart for explaining a method of applying a heat storage material to a refrigerating machine regenerator in a refrigerating machine regenerator according to a preferred embodiment of the present invention.

  5 and 6 are diagrams for explaining a method of applying a heat storage material to the regenerator for the refrigerator in the regenerator for the refrigerator according to a preferred embodiment of the present invention. Specifically, FIG. 5 shows that a large number of mats are formed from the random wire type, and FIG. 6 shows that a large number of mats are used to be inserted into the housing.

  First, a readily available random wire is crimped by a crimping device or the like (S511). At this time, a normal crimping apparatus can be used as the crimping apparatus. When the random wire is crimped, the thermal conductivity and / or air permeability in the housing is taken into consideration in advance. That is, the internal thermal conductivity and / or air permeability is grasped in advance, and thereby, the degree of pressure bonding of the random wire is varied to obtain an optimum thickness.

  The crimped random wire is vacuum sintered in a sintering furnace as shown in FIG. 5 to form a base mat 47 (S513). The sintering furnace is not particularly limited and may be any apparatus that can perform normal vacuum sintering. The base mat 47 preferably has as large an area as possible. This is because the wider the base mat is, the more mats are separated from the base mat, thereby enabling cost savings.

  The base mat 47 formed by the vacuum sintering method as described above is punched into a predetermined form using a punching apparatus to separate the mat 48 (S515). The fixed-form mat 48 is circular, rectangular, or polygonal, and can be selected according to the shape of the housing. At this time, the mat 48 is preferably separated into as many mats as possible from the base mat. The size of the mat is preferably approximately the same as the size inside the housing. That is, it is preferable that the size of the mat is as small as possible than the size in the housing. Then, when the mat is inserted into the housing, it is not sandwiched inside the housing or cannot be moved freely.

  A number of mats 48 separated from the base mat 47 are inserted in a row in the housing 340 provided in advance as shown in FIG. 6 (S517). At this time, the number of mats 48 inserted into the housing 340 may change depending on the thermal conductivity and / or air permeability in the housing. That is, if the thermal conductivity and / or air permeability in the housing is not good, a smaller amount of mat is inserted into the housing. After all, according to the thermal conductivity and / or air permeability in the housing, the degree of adhesion between the mats 48 and 48 ′ inserted into the housing 340 is adjusted so that the optimum thermal conductivity and / or air permeability is always obtained. Can be maintained.

  In the prior art, since the random wires are integrally crimped and then inserted into the housing, heat is easily transferred through the housing, thereby causing a problem of a large heat transfer loss.

  However, as in the present invention, since a large number of mats 48 are sequentially inserted into the housing 340 in a row, a constant boundary layer is formed between the mats 48 and 48 ', and heat transfer is delayed. The loss due to can be reduced.

It is a figure which shows the refrigerator by a prior art. It is a figure which shows the regenerator for refrigerators of FIG. It is a figure which shows the regenerator for refrigerators by preferable one Embodiment of this invention. 5 is a flowchart for explaining a method of applying a heat storage material to a refrigerating machine regenerator in a refrigerating machine regenerator according to a preferred embodiment of the present invention. It is a figure for demonstrating the method to apply the thermal storage material to the regenerator for refrigerators in the regenerator for refrigerators by preferable one Embodiment of this invention. It is a figure for demonstrating the method to apply the thermal storage material to the regenerator for refrigerators in the regenerator for refrigerators by preferable one Embodiment of this invention.

Claims (13)

A housing having a predetermined space inside and engaged with the displacer;
A heat storage material formed by inserting a number of mats provided in advance from a base mat into the housing;
An end cap attached to the tip of the housing;
A regenerator for a refrigerator, comprising:   The regenerator for a refrigerator according to claim 1, wherein the plurality of mats are formed of a random material.   The regenerator for a refrigerating machine according to claim 1, wherein the plurality of mats are filled in a row in the housing.   The regenerator for a refrigerating machine according to claim 1, wherein the plurality of mats are provided in advance so as to match a diameter inside the housing.   The regenerator for a refrigerating machine according to claim 1, wherein the thickness of the mat varies depending on a heat transfer coefficient and / or air permeability inside the housing.   The regenerator for a refrigerating machine according to claim 1, wherein the number of mats inserted into the housing varies depending on a heat transfer coefficient and / or air permeability inside the housing.   A heat storage material for a regenerator for a refrigerating machine, wherein the heat storage material inserted into the regenerator for the refrigerating machine is composed of a number of mats filled in the housing.   The heat storage material for a regenerator for a refrigerating machine according to claim 7, wherein the plurality of mats are made of random wires made of the same material. Forming a base mat by vacuum sintering a prebonded random wire;
A step of punching the base mat to separate a number of mats of a certain form;
Inserting the separated mats into a housing in a row;
A method for forming a heat storage material for a regenerator for a refrigerator.   The method for forming a heat storage material for a regenerator for a refrigerating machine according to claim 9, wherein the thickness of the base mat changes according to the degree of pressure bonding in the pressure bonding process.   The method for forming a heat storage material for a regenerator for a refrigerator according to claim 9, wherein at least one mat is separated from the base mat.   The method for forming a heat storage material for a regenerator for a refrigerating machine according to claim 9, wherein the number of mats inserted into the housing changes according to the degree of adhesion between the mats.   The method of forming a heat storage material for a regenerator for a refrigerating machine according to claim 9, wherein the shape of the mat of the certain form is one of a circle, a rectangle and a polygon.

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