JPH0798189A - Heat accumulator - Google Patents

Abstract

PURPOSE:To facilitate a laminating operation of heat storage elements and reduce the manufacturing cost of a heat accumulator by forming a heat storage elements of porous material and providing a space between the elements. CONSTITUTION:A heat accumulator 2 of a regenerating heat exchanger to be used for an external combustion engine is formed of a plurality of heat storage elements 3 laminated coaxially in a casing 1. Each element 3 is formed in a shape having a disclike body 3a and a leg 3b protruding from one end face of the body 3a, and formed by integrally molding a porous material. The plurality of the elements 3 are so laminated as to generate a space 4 through the legs 3b in a flowing direction of operating gas to form the accumulator 2. Heat is transferred between the gas and the accumulator 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat storage body, and in particular,
The present invention relates to a heat storage body used in an external combustion engine such as a Stirling cycle (including a Wilmier cycle).

[0002]

2. Description of the Related Art Characteristics required for a heat storage body of a regenerative heat exchanger used in an external combustion engine such as a Stirling cycle are as follows. When using the engine at high speed, the working gas as a fluid moves in a very fast cycle, so the contact area between the heat storage body and the working gas is as wide as possible in order to transfer heat to and from the working gas as quickly as possible. Or 2. 2. Maximize the heat capacity to remove as much heat as possible from the hot working gas and store it. It is preferable that the flow direction of the working fluid be as adiabatic as possible so that the temperature on the low temperature side of the heat storage body does not rise due to heat conduction in the heat storage body.

Conventionally, there is a heat storage body of the regenerative heat exchanger formed by laminating wire mesh. However, in a heat storage body in which such a wire mesh is laminated, a considerable number of wire meshes are required to improve heat storage performance, and the stacking process becomes very complicated, and the heat storage body rises in price. There was a problem.

[0004]

SUMMARY OF THE INVENTION In view of the above problems of the prior art, the main object of the present invention is to ensure heat insulation in the flow direction of the fluid in the heat storage body provided in the fluid passage. In addition, it is to provide an improved heat storage body for cost reduction.

[0005]

According to the present invention, such objects are laminated in a fluid passage through which the fluid is passed in order to transfer heat to and from the fluid. A heat storage body composed of a plurality of heat storage elements, wherein the heat storage element integrally has a protrusion made of a porous body and protruding in the stacking direction, and the protrusions are brought into contact with adjacent ones. It is achieved by providing a heat storage body characterized by being laminated on.

[0006]

By doing so, since the surface area of each hole of the porous body forming the heat storage element is large and each hole is intricate, the contact area between the fluid and the porous body becomes extremely wide, and the contact area between the both is increased. In this way, heat can be transferred quickly and the heat accumulating elements to be laminated are formed of a porous body, so that the protrusion protruding in the laminating direction can be easily integrally formed. When a plurality of formed heat storage elements are stacked, a space portion is generated between adjacent heat storage elements, so that a heat insulating effect is produced by the space portion between the heat storage elements.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a fragmentary side view showing a regenerative heat exchanger used in an external combustion engine to which the present invention is applied. The regenerative heat exchanger includes a cylindrical casing 1 and a heat storage body 2 coaxially provided in the casing 1. The fluid, which is the working gas of the external combustion engine, flows in the casing 1 so as to appropriately reciprocate in the axial direction as shown by arrows A and B in the drawing.

The heat storage body 2 is composed of a plurality of heat storage elements 3. The heat storage element 3 is made of a porous sintered body, and is formed by solidifying the chips and powders of a metal such as copper integrally bonded by diffusion bonding or brazing. The porous body is not limited to the above metal, but may be made of ceramics, for example.

As shown in FIG. 1, the heat storage element 3 has a disk-shaped body 3a having an outer diameter equal to the inner diameter of the casing 1 and a protrusion from one end surface of the body 3a. A pair of legs 3 protruding in the axial direction and parallel to each other
and b are integrally formed. Then, the leg portions 3b are attached to the flat end faces of the body portions 3a of the adjacent heat storage elements 3.
The heat storage elements 3 are coaxially laminated so that the projecting ends of the heat storage elements 3 come into contact with each other, and the heat storage body 2 is formed in the casing 1.

In the thus constructed regenerative heat exchanger, the working gas flows in and passes from either direction indicated by the arrow A or B in FIG. Heat is exchanged with the body 2.
According to the present invention, as described above, since the body portions 3a of the heat storage elements 3 in the stacked state are in contact with each other only through the leg portions 3b, the space portion 4 is provided between the adjacent body portions 3a. Has been.

As described above, due to the small contact portion between the heat storage elements 3 and the heat insulating function of the space portion 4,
Since the heat stored in each body portion 3a is not easily transferred to the adjacent ones and the heat conduction in the flow direction of the working gas is suitably blocked, the heat conduction from the high temperature portion to the low temperature portion is suppressed. obtain.
Therefore, in the heat storage body 2, a clear temperature gradient in the flow direction of the working gas can be obtained, and high efficiency of heat regeneration can be achieved.

FIG. 3 is a view similar to FIG. 1 showing a second embodiment according to the present invention. The same parts as those in the above embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. In the second embodiment, the shape of each heat storage element 5 is different from that of the first embodiment, and the configuration and the like are the same as those of the first embodiment.

The heat storage element 5 has a body portion 5a similar to that of the first embodiment, as shown in FIG. 4 which is similar to FIG.
And four leg portions 5b projecting in the axial direction as protrusions from one end surface of the body portion 5a and arranged at equal angular pitches in the circumferential direction, are integrally formed. Then, the heat storage elements 5 are coaxially laminated in the same manner as in the above-described embodiment, and the heat storage body 2 is formed in the casing 1. In the second embodiment, the same operational effect as that in the above-described embodiment is obtained. .

[0015]

As described above, according to the present invention, since the heat storage element is formed by stacking the heat storage elements formed of the porous body, the stacking workability is extremely easy, and the manufacturing cost of the heat storage body is reduced. It is possible to reduce the cost, and since the heat storage element is provided with a protrusion to reduce the contact area between adjacent heat storage elements, a space portion is created between the heat storage elements, and the heat insulation effect of each heat storage element causes each heat storage element to have a space. The heat conduction between the two is suitably blocked, and a clear temperature gradient from the high temperature portion to the low temperature portion of the heat storage body is obtained, so that the heat regeneration can be made highly efficient. In particular, when used in the Stirling cycle, it is possible to favorably cope with the flow of the working gas in a short cycle.

[Brief description of drawings]

FIG. 1 is a cutaway side view of a main part of a regenerative heat exchanger of an external combustion engine to which the present invention has been applied.

FIG. 2 is a perspective view showing the external appearance of a heat storage element according to the present invention.

FIG. 3 is a view similar to FIG. 1 showing a second embodiment.

FIG. 4 is a view similar to FIG. 2 of the second embodiment.

[Explanation of symbols]

 1 Casing 2 Heat storage body 3 Heat storage element 3a Body 3b Leg 4 Space 5 Heat storage element 5a Body 5b Leg

Claims (1)

[Claims] 1. A heat storage body comprising a plurality of heat storage elements stacked in a fluid passage for passing the fluid in a flow direction of the fluid in order to transfer heat to and from the fluid, wherein the heat storage element is A heat storage body comprising a porous body and integrally having a protrusion protruding in the stacking direction, and being stacked so that the protrusion abuts an adjacent one.