JPH0229960B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat exchanger, and more particularly to a heat exchanger equipped with a heat pipe and a heat storage material that undergoes a phase change between solid and liquid phases.

Heat pipes transport heat as the latent heat of vaporization of the working liquid sealed inside, and have thermal conductivity that is tens to hundreds of times higher than that of copper, the metal with the highest thermal conductivity. What you have is
As is well known, heat pipes have conventionally been used in various devices such as heat exchangers by taking advantage of their excellent properties.

By the way, in a normal heat pipe, if there is a temperature difference between the two ends, heat transport will naturally occur, so for example, when cooling any member or part, the temperature of the heat absorbing source that carries away the heat may be caused by some reason. If the temperature rises, the component or part to be cooled will not be able to be cooled or, on the contrary, will be heated. Furthermore, the above situation is the same when heating any member or part; if the temperature of the heat source drops for some reason, the member or part that should be heated cannot be heated, or conversely, it cools down. It becomes a thing. Therefore, in order to solve the above-mentioned inconvenience, conventionally,
A heat exchanger has been proposed that uses a heat storage material and is configured so that the heat storage material acts as a heat absorption source when the temperature of the heat absorption source increases, or the heat storage material acts as a heat source when the temperature of the heating source decreases. There is.

The heat storage materials used in this type of heat exchanger include those that utilize heat capacity such as water, those that utilize heat storage during phase change between solid and liquid phases, or those that utilize latent heat of vaporization. Heat storage materials that utilize heat capacity have the problem that their heat storage capacity is too small, and heat storage materials that utilize latent heat of vaporization have the problem that the volume change during evaporation is too large, and as a result, during the solid-liquid phase change, It is considered preferable to use a heat storage material that utilizes the latent heat of .

Conventionally, calcium chloride hexahydrate (CaCl ₂ 6H ₂ O, melting point = 29.92℃,
latent heat = 45Kcal/Kg), sodium thiosulfate pentahydrate (Na ₂ S ₂ O ₃ 5H ₂ O, melting point = 48.2°C) or octadecane (C ₁₈ H ₃₈ , melting point = 28°C, latent heat =
58.2Kcal/Kg) etc. are known. The ideal behavior of these heat storage materials is for the temperature to remain constant throughout until the phase change is completed, but in reality, a partial supercooled state appears and the temperature state initially assumed is not reached. Not only was the heat storage material not obtained, but there were also cases where the entire amount of heat storage material could not be used effectively.

This invention was made in view of the above circumstances, and aims to bring the behavior of a heat storage material that utilizes latent heat during a solid-liquid phase change as close to the ideal state as possible, and to utilize it effectively. The purpose of this invention is to provide a regenerative heat exchanger that can

Embodiments of the present invention will be described below with reference to the accompanying drawings.

One embodiment of the heat exchanger of the present invention will be described with reference to FIGS. 1 and 2. In these figures, reference numeral 1 indicates a heat pipe, and this heat pipe 1 is similar to a normal heat pipe. A wick 2 is attached to the inner peripheral surface, and an appropriate working fluid is sealed therein. A sealed container 3 is provided concentrically at a predetermined location on the outer periphery of one end of the heat pipe 1 over a certain length so as to surround the end. A variable heat storage material 4 is enclosed, and therefore the heat storage material 4 is in close contact with the outer peripheral surface of one end of the heat pipe 1 over a predetermined length. Further, a metal cover 5 is provided concentrically around the outer circumference of the sealed container 3, and a wick 6 made of metal or the like is provided on the inner peripheral surface of the cover 5 and the outer peripheral surface of the sealed container 3. A heat pipe 7 is formed in a space formed by the closed container 3 and is filled with an appropriate working fluid.

In the heat exchanger configured as above, the other end of the heat pipe 1 (lower end in FIG. 1) is placed at the heat source H, and the second heat pipe 7 is placed at the heat absorption source C, Furthermore, if a material whose melting point is slightly lower than the temperature of the heating source H is selected as the heat storage material 4, the heat given from the heating source H to the other end of the heat pipe 1 is transferred by the working fluid inside the heat pipe 1. The latent heat is carried to the one end side, the heat storage material 4 is melted by the heat, and the heat is stored as the latent heat at that time. A part of the heat given to the heat storage material 4 is
The heat is carried to the heat absorption source C by the heat pipe 7 provided on the outer periphery of the heat storage material 4, but since heat is always given to the heat storage material 4 from the heat source H by the heat pipe 1, the phenomenon is that the heat source H The heat is transferred to the heat absorption source C via the heat pipes 1 and 7 and the heat storage material 4.

In the above heat exchanger, when the temperature of the heating source H falls to about the melting point of the heat storage material 4,
Since there is no temperature difference between the two ends of the heat pipe 1, no heat transport occurs in the heat pipe 1, but the temperature of the heat storage material 4 is promoted to be uniform due to the action of the heat pipe 7, and the temperature difference between the heat storage material 4 and the heat pipe 7 is promoted. Since there is a temperature difference between the heat absorbing source C and the heat storage material 4,
Heat exchange occurs between the heat absorbing source C and the heat pipe 7, and as a result, the heat storage material 4 gradually radiates heat and solidifies. Even in this case, since the heat storage material 4 is in contact with the heat pipe 7 over a wide area, a supercooled state does not occur, and uniform solidification occurs throughout.
Further, since the heat pipe has a uniform temperature due to its characteristics, the surface area of the outer peripheral side of the heat storage material 4 is substantially expanded by the heat pipe 7, thereby improving the heat exchange characteristics.

Therefore, in the above heat exchanger, even if the temperature of the heating source H falls, until the heat storage material 4 is almost completely solidified, heat can be given to the heat absorbing source C, and the The heat transfer time from the heat storage material 4 to the heat absorption source C in this case is determined by selecting the type of the heat storage material 4 as appropriate,
Moreover, by increasing the amount, the length can be increased.

In addition, since the above heat exchanger has a structure in which the heat storage material 4 is interposed between the heat pipes 1 and 7, contrary to the above case, the end side where the heat storage material 4 is provided is connected to the heat source. Even if the opposite end side is used as a heat absorption source, the same effect as described above can be obtained.

FIG. 3 shows another embodiment of the heat exchanger of the present invention. In this figure, the heat pipe on the outer peripheral side of the heat storage material 4 is omitted, and this heat exchanger is buried in the heat storage material 4. A fin 8 is provided at one end of the heat pipe 1 so as to do so. In such a configuration, the heat transfer area between the heat pipe 1 and the heat storage material 4 becomes wider, so that the heat storage material 4 can be used effectively without causing local overheating or supercooling.

As explained above, according to the present invention, another heat pipe is provided concentrically and closely on the outer periphery of the heat storage material which is concentrically arranged in close contact with a predetermined location on the outer periphery of the heat pipe. The area for heat and heat dissipation is expanded, preventing local overheating and overcooling of the heat storage material, which allows the heat storage material to behave close to the ideal state, allowing for effective use of the material, and improving the effectiveness of the heat storage material as expected. It is possible to obtain effects such as being able to act.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a view taken along the - line in FIG. 1, and FIG. 3 is a sectional view of another embodiment. 1: heat pipe, 3: airtight container, 4: heat storage material, 7: heat pipe.

Claims (1)

[Claims] 1. A sealed container filled with a heat storage material that undergoes a phase change between solid and liquid phases is placed concentrically and tightly at a predetermined location on the outer periphery of a heat pipe, and heat is applied to the outer periphery of the sealed container. A regenerative heat exchanger characterized in that pipes are arranged concentrically in close contact with each other and the heat stored in the heat storage material is extracted to a predetermined heat absorption source.