JPH02203197A - Heat transportation method - Google Patents

Abstract

PURPOSE:To prevent a heat carrier to come in contact with a pipe to reduce power required for transporting heat, and avoid the deterioration of the heat carrier and the pipe due to friction by a method wherein the heat carrier is mixed into a transfer medium after the specific gravity of the heat carrier is adjusted, and transferred along the pipe. CONSTITUTION:A heat carrier to be used is composed of a phase change substance 1 and a specific gravity adjusting agent which is a vapor 2a sealed in micro-capsules 4. The seal ratio of the vapor 2a is determined so that the specific gravity of the heat carrier almost accords with that of a transfer medium in consideration of the amount of the phase change substance in use and the specific gravity of the phase change substance 1 and the transfer medium. The heat carrier is mixed into the transfer medium and transferred along pipe 100. The phase change substance 1 releases the latent heat at a radiator 11 (in cold heat or heat use system), and changes from solid to liquid phase, for example. Next, the phase change substance 1 receives cold heat or heat at a heat receiver 12, changes from liquid to solid phase, and is stored in a heat storage 13. The heat carrier is easily carried by the transfer medium and smoothly transferred without an increase in the friction against the wall of the pipe 100 as the heat carrier 1 has nearly the same specific gravity as the transfer medium.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for transporting heat using latent heat of a phase change material.

(Prior Art) Conventionally, in order to transport heat, it has been common to give a temperature difference to water or other liquid and transport the sensible heat change.

For example, in order to transport cold energy, cold water at around 5℃ in the cold heat storage tank is taken out and sent to the cold energy utilization system, where the cold energy is released and the water heated to about 10 degrees Celsius is transferred to the cold heat storage tank. This was done by returning the water to the interior and sending it again as cold water at around 5°C to the above-mentioned usage system.

However, in heat transport technology that utilizes the change in sensible heat of water (from 5°C to over 10°C), the heat capacity per unit volume of the heat transport medium (hereinafter referred to as heat medium) such as water is Due to its small size, there were the following problems.

That is, in order to transport a large amount of heat, a large amount of heat medium must be transferred. For this reason, it is necessary to use pipes with a large diameter for transferring the heat medium, resulting in enormous equipment costs. In addition, it was necessary to increase the transportation power, and the transportation cost was also enormous9.

In order to solve the above-mentioned problem, a technique using latent heat has recently been developed.

For example, to transport cold heat, a sherbet-like material containing fine ice particles or a mixture of ice particles and water is used as a heat medium.
A technology has been developed that utilizes the latent heat of ice.

In addition, to transport heat, a phase-change material that receives heat and becomes a liquid and radiates heat and becomes a solid is encapsulated in microcapsules.
A technique has been developed in which this is mixed into a transfer medium (for example, water, which is always liquid in the operating temperature range) as a heat medium (see Japanese Patent Publication No. 56476/1983).

As shown in FIG. 4, the principle of this technology is that a mixture of microcapsules M containing the above-mentioned phase change substance and water W is transferred as a heat medium through a pipe 100, and a radiator (thermal heat utilization system) 11 , the latent heat in this phase change material is dissipated. This turns the phase change material into a solid. Next, when transferred to the heater 12, the phase change material receives heat and changes from solid to liquid.

In this state, it is stored in the heat storage tank 12 as a heat medium.

When the heat is utilized in the radiator 11, the mixture of the microcapsules M and water W is taken out from the heat storage tank 13 into the pipe 100 and transferred to the radiator 11.

(Problems to be Solved by the Invention) However, the above techniques that utilize the latent heat of ice and techniques that utilize the latent heat of the microcapsules M encapsulating a phase change substance have the following problems.

That is, if the specific gravity of the microcapsules M encapsulating the phase change substance and the transfer medium is significantly different, the chances of the microcapsules M coming into contact with the wall of the piping during transfer increase.

For this reason, not only does the loss due to frictional force increase and the transfer power becomes large, but also the deterioration due to wear and abrasion of the microcapsules M sharply increases, and the wear and deterioration of the piping also increases.

Moreover, if the friction is intense, a large amount of frictional heat is generated, and when cold energy is transported, a large amount of cold energy is lost during transportation.

The present invention has been made in view of the above points, and its purpose is to eliminate contact between the heat medium and piping in a heat transport technology that utilizes the latent heat of the heat medium, and to improve the transfer power of the heat medium. An object of the present invention is to propose the above-mentioned method of transporting heat, which can reduce the amount of heat transfer and eliminate frictional deterioration of the heat medium and piping.

(Means for Solving the Problems) In order to achieve the above object, the present invention uses a phase change material,
Microcapsules encapsulating a mixture with a specific gravity adjuster are used as a heat medium, and by adjusting the mixing ratio, the specific gravity of the heat medium is made to approximately match the specific gravity of the transfer medium in the operating temperature range, and the heat after the specific gravity adjustment is A medium was mixed into the transfer medium to be transferred within the piping.

Further, the heat transfer medium may be a granular material made of a mixture of a phase change substance and a specific gravity regulator.

(Function) In the present invention, the amount of the specific gravity adjusting agent is adjusted to make the specific gravity of the heat medium approximately equal to the specific gravity of the transfer medium.

The required amount of the heat medium adjusted to approximately the same specific gravity as the transfer medium is mixed into the transfer medium and transferred through the piping to create a heat (cold or hot) utilization system. Heat reception (
Heat is transported by circulating the cold or hot) system and the heat storage (cold or hot) system.

At this time, since the specific gravity of the heat medium and the transfer medium are substantially the same, the heat medium circulates in a state where it is uniformly mixed into the transfer medium.

(Example) FIG. 1 shows an example of a heat medium used in the transportation method according to the present invention. In this example, a phase change substance 1 and a gas 2a as a specific gravity adjusting agent are enclosed in microcapsules 4. ing.

Here, the filling ratio of the gas 2a is determined by taking into account the amount of phase change material 1 used, the specific gravity of this phase change material 1, and the specific gravity of the transfer medium, so that the specific gravity of the heat medium and the transfer medium are approximately equal. It is determined.

In addition, the phase change substance 1 may vary depending on the type of heat to be transported (cold or hot), the operating temperature range, etc., but water, fat,
Paraffin, hydrated salts, etc. are preferably used.

In addition, the gas 2a includes air, nitrogen, CO2, Ar
Inert gases such as are preferably used.

Note that instead of the gas 2, a liquid having a lower specific gravity than the phase change substance 1, such as a low molecular weight alcohol, ether, or ester, can be used. This lightweight liquid may undergo a phase change from liquid to gas depending on the operating temperature range, and in this case, there is an advantage that the latent heat of the specific gravity adjuster can also be used for heat transport.

FIG. 2 shows another example of the heat medium used in the transportation method according to the present invention. In this example, a phase change substance 1 and a heavy substance 2b such as sand as a specific gravity adjusting agent are enclosed in microcapsules 4. are doing.

In the example of FIG. 2 as well as the example of FIG. 1, the inclusion ratio of the heavy object 2b is determined by taking into account the usage amount and specific gravity of the phase change material 1 and the specific gravity of the transfer medium.

Further, as the phase change material 1, the same material as in the example shown in FIG. 1 is used.

Furthermore, in addition to the above-mentioned sand, the heavy object 2b may include glass scraps, various ceramic powders, natural or synthetic resin powders, solids having a specific gravity higher than the phase change material 1 such as metal particles, or asphalt, or other natural or synthetic resins. A liquid having a higher specific gravity than the phase change substance 1 such as liquid can be used,
Similar to the case of the above-mentioned lightweight liquid, this heavy liquid may undergo a phase change from liquid to solid depending on the operating temperature range, and in this case, the ratio II! There is an advantage that the latent heat of the conditioning agent can also be used for heat transport.

Similar to the conventional heat transport technology shown in FIG. 4, the heat medium shown in FIGS. system)
At step 11, the latent heat of the phase change material 1 is dissipated, and the phase change material 1 undergoes a phase change, for example, from solid to liquid. Next, the phase change material 1 receives cold or hot heat in the heat receiver 12, undergoes a phase change from liquid to solid, and is stored in the heat storage tank 13.

At this time, since the heat medium shown in FIGS. 1 and 2 has a specific gravity equal to that of the transfer medium, it is easily entrained by the transfer medium and moves inside the pipe 100 to reduce friction with the pipe wall. As the number increases, it is transferred smoothly.

FIG. 3(A) shows yet another embodiment.

This example differs from the above embodiments in that it does not use microcapsules, and therefore has the following characteristics.

First, when the phase change material 1 undergoes a phase change between solid and liquid,
The mixing ratio of phase change material 1 and specific gravity adjuster 2 must always be the same. That is, for example, when the phase change substance 1 whose phase has changed from solid to liquid is mixed with the transport medium 3, when the phase changes from liquid to solid again, the specific gravity adjustment that exists around the liquid phase change substance 1 Since the abundance ratio of agent 2 is different, the specific gravity of the granules when solidified again is different from that when the original (solid) granules were prepared.

Therefore, in this example, in order to prevent the occurrence of such a phenomenon,
The m-adjusting agent 2 is selected to be one that has good compatibility and compatibility with the phase change substance 1, but has no compatibility or compatibility with the transport medium 3.

By using such a specific gravity adjusting agent 2, when the phase change substance 1 undergoes a phase change from solid to liquid, the (liquid) phase change that originally constituted one granule is removed, as shown in the figure. substance 1
The movement of the (liquid) phase change substance 2a, which was floating only in the vicinity of the particle a and constituted other particles, to the vicinity is blocked and prevented by the transport medium 3.

Therefore, when the phase change materials 1a, lb change into solids, the specific gravity adjusting agent 2 floating only in the vicinity of each phase change material 1a, lb is taken in, and the composition and specific gravity of the original granules and the gap are changed. becomes.

Note that the other configurations and operations are the same as those of the above-described embodiments, and therefore the description thereof will be omitted.

FIG. 3(B) shows yet another embodiment, which also does not use microcapsules.

Specifically, a phase change material (for example, high-density polyethylene particles) and a specific gravity adjuster are mixed in a predetermined ratio to form one granular material 5.
The melting point of the surface layer 5a of the granules 5 is set to the inner layer 5b.
It is higher than that of . By doing this,
Only the inside 5b undergoes a phase change due to heat radiation or heat reception, and does not melt into the transfer medium when the phase changes from solid to liquid.

In order to manufacture the granules 5 having the above structure, first, the melting point of only the surface layer 5a is increased by irradiating γ-rays on the granules formed at a predetermined mixing ratio. As a result, only the inside 5b melts at high temperatures, even though they are made of the same material.

(Effects of the Invention) According to the heat transport method according to the present invention detailed above, the specific gravity of the heat medium is equal to the specific gravity of the transfer medium and between the paths, so that the heat medium is easily entrained by the transfer medium. .

As a result, the chances of the heat medium coming into contact with the pipe wall during transfer within the pipe are reduced, and even if contact occurs, it can smoothly enter the flow of the transfer medium, reducing the friction between the pipe wall and the heat medium. is significantly reduced.

Therefore, the power for transferring the heat medium can be drastically reduced, and wear and deterioration of the piping and the heat medium can be reduced. Moreover, since no frictional heat is generated when cold energy is transported, there is no loss of cold energy during transportation.

[Brief explanation of the drawing]

FIGS. 1 and 2 are explanatory diagrams showing an example of a heat medium used in the heat transport method according to the present invention, and FIG. FIG. 4 is an explanatory diagram showing an example of the heat transport mode of the present invention and the conventional heat transport mode. 1... Phase change substance 2... Specific gravity adjuster 3...
・Transportation medium 4...Microcapsules 100
···Piping

Claims (3)

[Claims] (1) Microcapsules encapsulating a mixture of a phase change substance and a specific gravity adjusting agent are used as a heating medium, and by adjusting the mixing ratio, the specific gravity of the heating medium approximately matches the specific gravity of the transfer medium in the operating temperature range. A method for transporting heat, characterized in that the heat medium after specific gravity adjustment is mixed into the transfer medium and transferred within the pipe. (2) A method for transporting heat, wherein the heat medium according to claim 1 is a granular material made of a mixture of a phase change substance and a specific gravity regulator. (3) A claim characterized in that the granules made of the mixture are formed so that the surface layer has a high melting point and the inside has a low melting point, and only the inside liquefies when the temperature is increased. The method for transporting heat according to item 2.