JPH0674957B2 - Heat exchanger - Google Patents

Description

The present invention relates to a heat exchanger, and more particularly to a heat exchanger using a novel heat pipe having three heat exchange points.

In a system that effectively collects, stores, and uses heat from a heat source whose temperature fluctuates, such as solar heat or factory wastewater, when the heat source temperature becomes lower than the temperature in the heat storage tank,
It is necessary to prevent backflow of heat from the heat storage tank to the heat source. For this purpose, a storage system using a heat diode type heat pipe that transfers heat only in a certain direction has already been proposed. However, in such a conventional system, two types of heat pipes, one for heat storage and the other for heat dissipation, are used alternately, and the energy on the heat source side is used by one heat pipe. It is always stored in the heat storage tank and then discharged to the user side by another heat pipe. That is, the energy on the heat source side cannot be directly used on the load side. Therefore, in the conventional heat storage system using the heat diode type heat pipe, the exergy when the heat flows from the heat pipe to the heat storage material to the heat pipe has a remarkable drawback.

One object of the present invention is to effectively collect and store heat from a heat source whose temperature fluctuates, such as solar heat or factory wastewater,
And to provide a novel heat exchanger suitable for use.

Another object of the present invention is to use a part of energy of a heat source when the temperature of the heat source side is higher than the temperature of the load side when used for collecting heat from a heat source whose temperature fluctuates and storing the heat. A new heat exchanger that can directly transfer to the load side and store the rest, and when the temperature on the heat source side is lower than the temperature on the load side, can transfer heat from the heat storage material to the load side. It is to be.

The heat exchanger of the present invention which achieves the above objects has a thermosiphon function by itself having a wickless body between a wicked working fluid evaporator and a wickless working fluid condenser. One member and a second member having a thermosiphon function by itself having a body without a wick between a working fluid evaporating part with a wick and a working fluid condensing part without a wick, and a working fluid of the first member. A heat exchanger using a heat pipe in which a condensing part and a working fluid evaporating part of a second member are connected so that they are in contact with each other. The outer wall of the connecting portion is brought into contact with the heat storage material, and the working fluid condensing portion of the second member is inserted into the heat medium passage on the load side.

Referring to the accompanying drawings, a heat pipe used in a heat exchanger according to the present invention includes a first member A (hereinafter also referred to as siphon A) having a thermosiphon function by itself as shown in FIG. As shown in FIG. 2, it is directly connected to a second member (hereinafter also referred to as siphon B) having a thermosiphon function by itself. Siphon A
Is manufactured, for example, by evacuating a metal pipe (eg, copper pipe) 1 having one end closed in the illustrated shape, filling water or methanol, for example, as a working fluid 2, and closing the other end. To be done. In the thermosiphon having such a structure, the vapor flow of the working fluid having a large evaporation latent heat is responsible for heat transport, and the vapor-liquid equilibrium is established in the siphon interior 3, so that large heat transport can be performed with a small temperature difference. it can. The siphon A is functionally divided into three parts, that is, a working fluid evaporating part 4a (hereinafter sometimes referred to as an evaporating part or a heat absorbing part) and a wickless working fluid condensing part 5a (hereinafter called a condensing part or a heat radiating part). Sometimes)
And a heat insulating portion 6a of the body without a wick (the term "heat insulating portion is not necessarily appropriate, but this term is used in the sense that it is preferable that there is no heat exchange with an external system").
A wick 7 is preferably provided on the inner wall of the evaporation portion 4a so that the working fluid can be evaporated from the entire inner wall of the evaporation portion 4a.
The siphon A having such a structure has a thermosiphon function by itself. That is, when the evaporating section 4a is placed at the bottom and is heated, the working fluid in the evaporating section 4a evaporates and carries the heat upward, radiating heat in the condensing section 5a and condensing itself, and the inner wall of the siphon A. Along the evaporation section 4a
Run down to. That is, the siphon A has a function of transferring heat from the lower side to the upper side. However, even if the evaporating section 4a is set to the bottom and the condensing section 5a is heated, the condensing section 5a is immediately dried out, so the heat transfer from the upper side to the lower side is only the heat conduction along the siphon wall. ， Effective heat transfer by working fluid vapor cannot be expected. Ie siphon
A: It has almost no function of transferring heat from the upper side to the lower side.
The structure and operation of the siphon A having the thermosiphon function by itself are well known except for the peculiar shape of the condensing part 5a. The same applies to siphon B. That is, the siphon B also includes a working fluid evaporating section 4b, a working fluid condensing section 5b without a wick, and a heat insulating section 6b without a wick.
It is preferable to provide a wick 7 on the inner wall of the evaporator so that the working fluid can evaporate from the entire inner wall of the evaporation portion 4b. When the evaporation portion 4b is used at the bottom, heat transfer by the working fluid vapor is lower. From upwards only. However, in the siphon B, the evaporation portion 4b thereof has only the unique shape shown in the figure.

Condensing part 5a of siphon A and evaporating part 4b of siphon B
The reason for making the shape of peculiar as shown is that the efficiency of heat transfer between them is improved to facilitate direct connection, and that the shape shown is easy to manufacture. As long as these requirements are met, the specific shapes of the condenser 5a of siphon A and the evaporator 4b of siphon B are not critical. The heat pipe used in the present invention is formed by directly connecting the condenser section 5a of the siphon A and the evaporation section 4a of the siphon B as described above. Although not shown, the direct connection mode may be physical fitting or screwing of both members. Alternatively, as shown in FIG. 3, the condensing part 5a of the siphon A is
The heat pipe may be manufactured as an integral structure so that at least a part of the wall of the heat pipe constitutes a part of the wall of the evaporation portion 4b of the siphon B.

The heat pipe shown in Fig. 3 has an outside diameter of 25 with both ends closed.
mm, 500 mm long copper tube 8 in the center of a cap-shaped copper member 9
Is integrally provided with the copper pipe 8 to divide the copper pipe 8 into two chambers, an upper chamber and a lower chamber, and a central portion of the copper pipe 8 has a double pipe structure. Inner diameter of double tube is 12mm, length is 100mm
Is. The members 9 and the lower copper pipe 8 constitute the siphon A, and the member 9 and the upper copper pipe 8 above constitute the siphon B. Copper tube 8 divided by 9
In the upper and lower two chambers, methanol is enclosed as a working fluid 2 and the pressure is reduced in vacuum. In this example, the member 9 acting as the condenser wall of the siphon A directly constitutes a part of the evaporator wall of the siphon B. This means that the heat transfer from the siphon A to the siphon B is performed on the same side. In the illustrated example, a bronze mesh screen 10 as a wick is fixed to the inner wall of the evaporation section by a spring 11 in both siphons A and B so that the working fluid can be evaporated on all the inner wall surfaces of the evaporation section.

The heat pipe used in the present invention has three places where heat enters and leaves the outside. In the example of FIG. 3, those points are Part I (the outer wall of the evaporation section of the siphon A) and Part II.
(Outer wall of the increased part of Siphon B) and then Part III
(Outer wall of condensing part of siphon B). In this example, the length of each part is 100 mm, and the distance between each part is 100 mm.
A long heat insulating part was provided.

FIG. 4 is a longitudinal sectional view for explaining an example of the heat exchanger of the present invention using the heat pipe of the type shown in FIG. In the same figure, devices and members other than the heat exchanger are shown diagrammatically. The heat exchanger of the present invention, which is designated by 20 in its entirety, includes a chamber 21 in which a heat source side heat medium (for example, water) flows as the lowest member and a chamber 22 in which a load side heat medium (for example, water) flows as the uppermost member. And a heat storage tank 23 sandwiched between both chambers. The peripheral wall of the heat storage tank 23 is made of a heat insulating material.
4, For example, lauric acid (melting point: 44 ℃) is stored. A large number of heat pipes 25 of the type shown in FIG. 3, the working fluid evaporating portion of those siphons A, that is, part I, is inserted into the heat source side heat transfer medium passage in the chamber 21, and the working fluid condensing of siphon B is condensed. Part or part III is inserted into the load side heat transfer medium path in the chamber 22, and the outer wall or part II of the connecting part of the siphon A and siphon B contacts the heat storage material 24 in the heat storage tank 23. The heat storage tank 23 is mounted by penetrating the heat insulating material wall. A solar heat collector 27 is attached to the heat source side heat medium passage 26 which the chamber 21 forms a part, and the heat source side heat medium that has collected the solar heat is circulated to the chamber 21 by the pump 28.
On the other hand, in the load side heat transfer medium passage 29 which the chamber 22 forms a part, the load side heat transfer medium is circulated from the chamber 22 by the pump 30 and radiated to the heat load 31 in the heat transfer medium passage.

When part I of the heat pipe 25 is at the bottom and the part II is covered with the heat storage material 24 and the heat medium warmed by solar heat is flowed around the part I, part of the heat is directly transferred to the part III. The rest is stored in the heat storage material around Part II.

On the other hand, if you want to use the stored heat,
It can be taken out from III. Also, when the temperature fluctuation of the heat source such as solar heat is large, the heat medium at a temperature lower than the temperature of the heat storage tank sometimes flows around Part I, but this heat pipe transfers heat from top to bottom. There is little unwanted backflow of heat, as it does not transfer (more precisely, there is no top-to-bottom heat transfer by the working fluid vapor).

When the latent heat storage method using an organic compound with a low melting point is adopted as the heat storage material, the heat to be transferred to the heat storage material from Part II of the heat pipe may not reach the entire heat storage material in the heat storage tank. In such a case, it is preferable to provide fins on the outer wall of the joint portion of the siphons A and B of the heat pipe for increasing the contact area with the heat storage material.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a first member (siphon A) of an example of a heat pipe suitable for use in the heat exchanger of the present invention, and FIG. 2 is a second member (siphon B) of the heat pipe of FIG. ), FIG. 3 is a vertical cross-sectional view of another example of a heat pipe suitable for use in the heat exchanger of the present invention, and FIG. 4 is a vertical section for explaining an example of the heat exchanger of the present invention. It is a side view. A ... Siphon A B ... Siphon B 1 ... Pipe 2 ... Working fluid 3 ... Space inside siphon 4a ... Evaporating part of siphon 4b ... Evaporating part of siphon 5a ... Condensing part of siphon A 5b …… Condensing part of siphon B 6a …… Adiabatic part of siphon A 6b …… Adiabatic part of siphon B 7 …… Wick 8 …… Copper tube 9 …… Mounted cap copper member 10 …… Bronze mesh screen 11… … Spring 20 …… Invention heat exchanger 21 …… Lower chamber 22 …… Upper chamber 23 …… Heat storage tank 24 …… Heat storage material 25 …… Heat pipe 26 …… Heat source side heat medium passage 27 …… Solar heat collector 28 …… Pump 29 …… Load side heat transfer medium 30 …… Pump 31 …… Heat load

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Bibliography Sho 59-195385 (JP, U) Rikai 57-77677 (JP, U) "Heat pipe and its application" Ohmsha, February 1980 Issued 2-3 pages [2] Thermosyphon

Claims (1)

[Claims] 1. A first member having a thermosiphon function by itself having a wickless body between a working fluid evaporating part having a wick and a working fluid condensing part having no wick, and a working fluid evaporating part having a wick. And a second member having a thermosiphon function by itself having a body without a wick between the working fluid condensing portion without the wick and the working fluid condensing portion of the first member and the working fluid evaporating portion of the second member. A heat exchanger using a heat pipe in which parts are connected so as to be in contact with each other, wherein the evaporation part of the first member is at the bottom and is inserted into the heat source side heat transfer medium passage, and the outer wall of the connection part is stored with heat. A heat exchanger that contacts the material and inserts the working fluid condensing part of the second member into the heat transfer medium path on the load side.