KR19980067649A - Combined Regenerator for Stirring Cycle Machines - Google Patents

Abstract

The present invention relates to a regenerator for a stir cycle machine operated by a regeneration cycle, wherein the internal space of the regenerator is divided into a plurality of regions, each of which is filled with a porous material having a different porosity. It is a novel combination regenerator which also improves the performance of the Stirring cycle machine as the flow loss of the regenerator is reduced and the regenerative and heat dissipation performance of the regenerator is excellent.

Description

Combined Regenerator for Stirring Cycle Machines

The present invention relates to a regenerator used in a Stirling cycle machine, such as a Stirling engine, a Stirling freezer, a VM (Vuilleumier) cycle heat pump, and in particular, a working fluid inside the Stiring cycle machine And a combined regenerator which reduces the flow loss generated when reciprocating the cold space and improves the effectiveness of the regenerator.

Stirling cycle machines are divided into hot and cold zones and are driven by regeneration cycles by regenerators located between each zone. The working fluid inside each zone maintained at high and low temperatures reciprocates through each zone through the regenerator, whereby heat transfer occurs between the working fluid and the regenerator. When the working fluid in the high temperature region moves to the low temperature region through the regenerator, the temperature is lowered while being regenerated in the regenerator. When the working fluid in the low temperature region moves to the high temperature region, the working fluid is radiated from the regenerator to increase the temperature of the working fluid.

Since the regenerator is mainly manufactured using a wire mesh with a considerably small flow area through which the working fluid can pass, most of the flow loss of the working fluid reciprocating inside the Stirling cycle machine occurs in the regenerator. Therefore, in order to improve the performance of the Stirling cycle machine driven by the regeneration cycle by the regenerator, it is essential to equip the regenerator with small flow loss and good usability.

Regenerator types include a gold mesh, honeycomb, sponge metal, and the like, but a metal mesh having a mesh number of 60 to 300 is generally used. Here, the number of meshes of the gold mesh represents the number of wires arranged in the length of 1 inch, and the larger the number of meshes of the mesh, the smaller the diameter of the wire to be used, but the smaller the distance between the wires, the smaller the flow path area.

When the Stirling Cycle unit is in operation, the working fluid inside the unit reciprocates the regenerator at least 300 times per minute. At this time, in the case of using a regenerator composed of a low mesh number, the flow loss is reduced, but the usefulness of the regenerator is poor. In contrast, in the case of using a regenerator composed of a gold mesh having a high mesh number, the usefulness of the regenerator becomes good, but the flow loss is increased. Therefore, in order to increase the performance of the Stirling cycle machine driven by the regeneration cycle by the regenerator, it is necessary to equip the reproducer having a low flow loss and a high usefulness by tradeoff between two conflicting conditions of flow loss and usefulness. Here, the usefulness of the regenerator indicates the heat storage and heat dissipation performance of the regenerator as a dimensionless value, for example, when the working fluid in the high temperature region moves to the low temperature region through the regenerator, the working fluid in the low temperature region has a high temperature. If the heat is transferred from the regenerator to the working fluid, the usefulness of the regenerator is 1, and if only half of the heat storage heat is released, the usefulness is 0.5.

1 schematically shows a conventional regenerator 4 mounted on a stirling cycle machine. In Fig. 1, the high temperature working fluid 3 and the low temperature working fluid 8 inside the high temperature side heat exchanger 2 and the low temperature side heat exchanger 9 are connected to the high temperature side piston 1 disposed at each end of each heat exchanger. The low temperature side piston 10 reciprocates through the regenerator 4 and heat transfers with the regenerator. The conventional regenerator 4 is made of a porous material or a porous structure of the same porosity. Such a conventional regenerator has a disadvantage in that any one of flow characteristics and heat transfer characteristics becomes poor. Until now, a method of reducing the thickness of the regenerator or manufacturing a porous material or a porous structure having a high porosity has been used as a method for reducing the flow loss caused by the regenerator. On the other hand, in order to improve the heat storage and heat dissipation characteristics of the regenerator, It has been used to fabricate porous materials or porous structures of increased thickness or low porosity. That is, these methods did not meet both aspects of reducing the flow loss in the regenerator and improving the usefulness of the regenerator.

An object of the present invention is to reduce the flow loss through the regenerator and improve the usefulness of the regenerator by providing a regenerator combining several kinds of porous materials or porous structures instead of the conventional regenerator consisting only of homogeneous porous materials or porous structures. .

1 is a schematic diagram of a conventional regenerator;

2 is a schematic diagram of a combined player according to the present invention;

Figure 3a is a graph showing the results of a comparative test of the pressure difference between the conventional regenerator and the regenerator of the present invention according to the number of reciprocating reciprocating flow of the working fluid.

3B is a graph showing the results of comparative tests of the regenerator usefulness of the conventional regenerator and the present invention according to the number of reciprocating reciprocating flows of the working fluid.

Explanation of symbols for the main parts of the drawings

1, 10: Piston

2, 9: heat exchanger

3, 8: working fluid

4: player

5: first player area

6: second player area

7: third player area

In order to achieve the above object, the present invention, in the regenerator used in the Stirling cycle machine operating in the regeneration cycle, the regenerator is divided into a plurality of regions, each of the porous material having a different porosity mutually Provided is a novel combined player that is charged.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 shows a schematic view of the combined regenerator 4 according to the invention, which is made by selecting a gold mesh having a different mesh number among various porous materials or porous structures. The inside of the player 4 is divided into a first player area 5, a second player area 6 and a third player area 7 according to the number of meshes of the installed gold mesh. In the present embodiment, the first regenerator region 5 on the side of the high temperature working fluid has a mesh of 60 meshes (a porous material having a high porosity), the second regenerator region 6 has a mesh of 120 meshes, and The third regenerator region 7 on the side with the working fluid is filled with a gold mesh having a mesh number of 200 (a porous material having a low porosity). In this embodiment, helium gas having a high viscosity at high temperature and a low viscosity at low temperature is used as the working fluid.

When the working fluid flows from the high temperature side heat exchanger (2) to the low temperature side heat exchanger (9), the hot working fluid having a high viscosity passes through the coarse first regenerator region (5) having a mesh number of 60 and then the second regenerator. As heat passes through the regenerator 4 as it passes through the region 6 and the third regenerator region 7, the temperature of the working fluid is significantly lowered and the viscosity is gradually lowered. That is, the denser regenerator is filled from the first regenerator region 5 to the third regenerator region 7, but the viscosity of the working fluid is sufficiently low so that the working fluid easily passes through these regions. On the contrary, when the working fluid flows from the low temperature side heat exchanger 9 to the high temperature side heat exchanger 2, the low temperature low temperature working fluid passes through the dense third regenerator region 7 without large flow resistance. Subsequently, heat transfer is carried out with the regenerator 4 while passing through the second regenerator region 6 and the first regenerator region 5, and the viscosity of the working fluid increases considerably while gradually increasing. That is, the viscosity gradually increases as the working fluid flows from the third regenerator region 7 to the first regenerator region 5, but the second regenerator region 6 and the first regenerator region 5 have a small mesh number. Because of the sparse gold mesh, the working fluid can easily pass through the regenerator 4. As a result, the flow loss is smaller than that of the conventional regenerator in which the entire regenerator region is composed of the same mesh number.

If the average porosity of the conventional regenerator and the combined regenerator of the present invention is the same, a dense gold mesh having a large mesh number constituting the combined regenerator of the present invention can be used, so that the combined regenerator has better heat storage and heat dissipation performance than the conventional regenerator. This is because the larger the number of meshes of the gold mesh, the smaller the diameter of the wire, the less the thermal inertia to exchange heat with the working fluid increases the usefulness of the regenerator.

3A and 3B are composed of a single type of gold mesh having a mesh number of 120 and a conventional regenerator (type A) having a porosity of 0.7, and a combination of three kinds of gold meshes having a mesh number of 60, 120, and 200, respectively, and having an average porosity. It is a graph which shows the result of the comparative test of this 0.7 type | mold combination type | system | group regenerator (B type). Fig. 3a shows the result of a comparative test of the pressure difference across the regenerator and the regenerator of the conventional regenerator and the regenerator of the present invention, ie, the flow loss through the regenerator, according to the number of times the working fluid reciprocates through the regenerator (or the operating speed). Fig. 3b shows the results of comparative tests of the regenerator utilization of the conventional regenerator and the present invention according to the number of times the working fluid reciprocates through the regenerator (or the operating speed).

As can be seen in Fig. 3a, in the region where the working fluid reciprocates the regenerator less than 400 rpm, the flow loss in the combined regenerator (type B) is almost the same as that in the conventional regenerator (type A). Turned out to be absent. However, it can be seen that in the region of 400 rpm or more, the flow loss of the combined regenerator is smaller than that of the conventional regenerator. Considering that the operating range of the Stirling cycle machine is 300 rpm to 800 rpm, it is obvious that the performance of the Stirring cycle machine can be improved when the combined regenerator is applied to the Stirling cycle machine.

Referring to Figure 3b comparing the usefulness of the regenerator, both the conventional regenerator (type A) and the combined regenerator (type B) of the present invention show that the usefulness of the regenerator decreases as the number of times the working fluid reciprocates. Able to know. This tendency is a commonly known result, and since the same tendency appears in the operating range of the Stirling cycle machine, the test was limited to an area of 300 rpm or less. As can be seen from the results shown in Fig. 3B, the combined type regenerator is not only more useful than the conventional type regenerator, but also the rate of decrease of the usefulness is small even when the operation speed is increased.

As mentioned above, although this invention was demonstrated to the preferred embodiment, this invention is not limited to this, In addition, it is possible to change or modify in various ways, without deviating from the range of this invention. For example, the number of regions constituting the combined regenerator may be 2 to 5, and as the working fluid, a combined regenerator using a working fluid having a low viscosity at a high temperature and a high viscosity at a low temperature other than helium gas is used. The order of the regions constituting the symbol may be configured in the reverse order of the embodiment of the present invention.

When the combined regenerator according to the present invention is applied to a stir cycle device driven by a regeneration cycle by a regenerator, such as a stir engine, a stir freezer, a VM cycle heat pump, etc., the flow loss of the working fluid is reduced and the heat storage and heat dissipation performance of the regenerator is excellent As a result, the performance of the Stirring cycle machine is also improved.

Claims (3)

For regenerators used in Stirling cycle machines operated by regeneration cycles and located between the hot and cold zones, The internal space of the player is divided into a plurality of areas, And each of the regions is filled with porous materials having different porosities. 2. The regenerator of claim 1, wherein the porous material is disposed such that the porosity of the porous material increases from one of the hot and cold regions toward the other. 3. The regenerator as set forth in claim 1 or 2, wherein said porous material comprises a gold mesh having different mesh numbers.