KR20040003449A - Composition for transmitting heat - Google Patents

Abstract

PURPOSE: A heat transfer composition is provided, to allow heat to be transmitted smoothly and to reduce the heat loss by increasing the heat remaining time. CONSTITUTION: The heat transfer composition comprises 100 ml of acetone; and 80-120 ml of isopropyl alcohol. Optionally the composition comprises further 60-90 ml of distilled water and/or 70-120 ml of isobutyl aldehyde based on 100 ml of acetone. Also the composition comprises further 50-110 ml of any one selected from pentane, isopentane and their mixture based on 100 ml of acetone. Preferably the ratio of pentane to isopentane in the mixture of pentane and isopentane is 1:2 to 1:1 by volume.

Description

Composition for heat transfer {Composition for transmitting heat}

The present invention relates to a heat transfer composition, in particular a heat transfer composition for use as a working fluid of the heat pipe, and more particularly, to facilitate heat transfer and at the same time the heat of the long residual heat and low heat loss It relates to a composition for delivery.

Since the principle of operation was first introduced in 1942 by Gaugler of the city of GM in 1942, research and development began in earnest in the United States and Europe in the mid-1960s, and started in Asia, Japan, India and China from the 1970s. At present, active research and development results are known. The heat pipe is vacuum exhaust after injecting working fluid into a sealed container. When one end is heated, the working fluid inside is vaporized, moved to the other side by the pressure difference, dissipates heat to the surroundings, and then condenses again. The structure returns to the heating section. Depending on the application, a substance causing capillary force may be inserted.

Wick, a key part of heat pipe operation, is an internal capillary structure that returns liquid working fluid from the condenser to the evaporator, usually in the form of a mesh or groove, which is dependent on the surface tension of the liquid. Causes capillary phenomenon. In addition to the capillary, the return of the liquid may use electromagnetic force, centrifugal force, osmotic pressure or gravity.

Heat transfer compositions used as the working fluid of the heat pipe as described above are usually a variety of freon gas, surfactant, distilled water, glycerin, aqueous sodium hydroxide, aqueous solution of vanadate, etc., but they do not have a relatively wide operating temperature range Or, there is a problem such as harmful to the human body and the environment or inexpensive, low heat transfer rate, too little heat remaining time to hold the heat.

For example, distilled water has a relatively wide operating temperature range, but has a disadvantage of corroding the material used for a long time, freon gas is harmful to humans and the environment. In addition, glycerin, aqueous sodium hydroxide and aqueous solution of vanadate has the disadvantage that the operating temperature range is not wide.

In addition, when manufacturing a heat pipe using the conventional working fluid as described above, in order to increase the heat transfer rate, heat transfer efficiency, etc. should have a wick as an essential structure, but a heat pipe having a wick structure The unit price is expensive.

If you do not use a wick, there is a thermophony (Thermosyphon), but the efficiency is significantly lower than the wick (Wick) heat pipe is a problem.

Accordingly, the technical problem to be achieved by the present invention is to provide a heat transfer composition that overcomes the above-mentioned disadvantages, in particular, the heat transfer rate is fast, the heat remaining time is long and the heat loss is low.

In addition, even if manufacturing a wickless heat pipe (Wickless Heat pipe) to provide a heat transfer composition (working fluid) for heat pipe that enables to manufacture a product that performs more than a wicked heat pipe at a low price and high efficiency It is.

In order to achieve the above technical problem, the present invention provides a composition for heat transfer comprising acetone and 80 to 120ml of isopropyl alcohol with respect to 100ml of the acetone.

In addition, the composition for heat transfer according to the present invention is acetone and isopropyl alcohol as an essential component in consideration of heat transfer rate, residual heat time and thermal efficiency, such as distilled water, isobutylaldehyde, pentane, isopentane, or pentane and isopentane It can be configured by appropriately adding a mixture of.

Looking specifically, when the composition for heat transfer according to the present invention consists of two components is a composition consisting of acetone and isopropyl alcohol,

When composed of three components, a composition consisting of acetone, isopropyl alcohol and distilled water, a composition consisting of acetone, isopropyl alcohol and isobutyl aldehyde, a composition consisting of acetone, isopropyl alcohol and pentane, and acetone, isopropyl alcohol and isopentane The composition consists of,

When composed of four components, a composition consisting of acetone, isopropyl alcohol, distilled water and isobutyl aldehyde, a composition consisting of acetone, isopropyl alcohol, distilled water and pentane, a composition consisting of acetone, isopropyl alcohol, distilled water and isopentane, acetone, A composition consisting of isopropyl alcohol, isobutyl aldehyde and pentane, a composition consisting of acetone, isopropyl alcohol, isobutyl aldehyde and isopentane, and a composition consisting of acetone, isopropyl alcohol, pentane and isopentane,

When composed of five components, a composition consisting of acetone, isopropyl alcohol, distilled water, isobutyl aldehyde and pentane, a composition consisting of acetone, isopropyl alcohol, distilled water, isobutyl aldehyde and isopentane, and acetone, isopropyl alcohol, distilled water , Pentane and isopentane,

When comprised in six components, it is a composition which consists of acetone, isopropyl alcohol, distilled water, isobutyl aldehyde, pentane, and isopentane.

Hereinafter, the nature and role of each material constituting the composition for heat transfer according to the present invention will be described.

Acetone (Chemical Formula: CH ₃ COCH ₃ ) is a kind of ketones (RCOR, R is an alkyl group) and its boiling point is relatively low at 56.3 ° C. Therefore, it is easy to evaporate even with a small amount of heat, so it plays a role of evaporating quickly with heat. That is, when acetone is used as a working fluid in the heat pipe, the evaporator can take heat from the evaporator and rapidly diffuse into the vacuum state, thereby performing a function of ultra-fast heat transfer. In short, acetone has a low boiling point, so it evaporates easily even at low temperatures, and diffuses at high speed in a vacuum, thereby transferring heat quickly.

Isopropyl alcohol [Chemical Formula: (CH ₃ ) ₂ CHOH] is a colorless liquid with an alcoholic flavor. The boiling point is 82.4 ° C, which is higher than that of acetone, but the evaporation rate is 2.88, which facilitates the smooth transfer of thermal energy. In other words, when used as a working fluid of the heat pipe, it serves to take the maximum amount of thermal energy to the top of the heat pipe.

In addition, since isopropyl alcohol is well soluble in water, it is possible to perform a smooth role when used in combination with water and to form a relatively stable heat transfer composition. In addition, the specific heat of isopropyl alcohol is 0.596 (Kcal / Kg ° C), which is relatively high, and when mixed with water having a specific heat of 1 (Kcal / Kg ° C) at an appropriate ratio, it is a very fast heat transferer. It will serve as a role.

Isobutylaldehyde [Chemical Formula: CH ₃ C (CH ₃ ) HCHO] has a boiling point of 64.2 ℃ which is somewhat higher than acetone, but it is considerably lower and has a high specific heat of 1.6 (Kcal / Kg ° C). . That is, when isobutylaldehyde is used as the working fluid of the heart pipe, the evaporator quickly takes heat and diffuses it into a vacuum state, thereby performing a function of ultra fast heat transfer called rapid heat transfer. In short, the function of acetone is in ultrafast heat transfer, and isobutylaldehyde serves as an adjuvant to assist in the function of acetone.

Pentane [Chemical Formula: CH ₃ (CH ₂ ) ₃ CH ₃ ] is a colorless liquid with a fresh smell and boiling point of 36.074 ° C., and isopentane (CH ₃ ) ₂ CHCH ₂ CH ₃ ] has a boiling point of 30 ° C. and an octane number Is quite high. Therefore, when pentane, isopentane, or a mixture thereof is used in the composition for heat transfer, the octane number exhibits high physical properties and serves to lengthen the heat retention time, that is, the residual heat time. Thus, the composition for heat transfer comprising pentane, isopentane or mixtures thereof has a long residual heat time, which is very effective for manufacturing a heating apparatus. In other words, it is possible to efficiently retain heat and efficiently realize a long time heating effect.

In constituting the composition according to the present invention with a substance that functions and functions as described above, the composition ratio of each of the substances is 80 to 120 ml of 100 ml of acetone, and 60 to 100 ml of acetone. 90 ml, any one selected from the group consisting of 70 to 120 ml of the isobutyl aldehyde to 100 ml of the acetone, the pentane, isopentane, and mixtures thereof may be included from 50 ml to 110 ml of the acetone 100 ml, and When a mixture of isopentane is used, the capacity ratio of pentane and isopentane may be 1: 2 to 1: 1.

The composition ratio of the heat transfer composition according to the present invention is determined through various tests of the present inventors in consideration of heat transfer rate, residual heat time and thermal efficiency.

Hereinafter, the present invention will be described in detail with reference to the following examples, and the present invention is not limited by the following examples.

<Example>

A heat transfer composition having a composition ratio as shown in Table 1 below is filled with about 2.0% of the internal capacity of a heat pipe, and has a diameter of 10Φ, a wick having a length of 1,000 mm, and a cylindrical heat pipe having a vacuum structure inside. It was prepared according to the heat pipe manufacturing method.

Composition 1 Composition 2 Composition 3 Composition 4 Composition 5 Composition 6 Composition 7 Composition 8 Acetone 15 ml 15 ml 15 ml 15 ml 15 ml 15 ml 15 ml 15 ml Isopropyl Alcohol 15 ml 15 ml 15 ml 15 ml 15 ml 15 ml 15 ml 15 ml Distilled water 10 ml 10 ml 10 ml 10 ml 10 ml Isobutylaldehyde 12 ml 12 ml 12 ml 12 ml Pentane 5ml Isopentane 10 ml 10 ml 10 ml 10 ml

Using the heat pipe manufactured as described above, and a conventional heat pipe having a conventional heat transfer composition and a wick, the same method was tested in an adiabatic sealed space to measure the flow rate, heat recovery rate, and maximum heating allowable temperature per cross section. The calculations are shown in Table 2 below. In the case of the flow rate and heat recovery rate per cross-sectional area, hot water of 100 ° C. was used, and in the case of the maximum heating allowable temperature, it was measured by an electric heater.

Composition 1 Composition 2 Composition 3 Composition 4 Composition 5 Composition 6 Composition 7 Composition 8 Conventional Heat Fight Inlet temperature (℃) 100 100 100 100 100 100 100 100 100 Outlet temperature (℃) 97 97.2 97.5 96 98.7 98 98.2 99 95 Flow rate per cross section 150-170 150-170 150-180 150-170 150-190 150-180 150-180 180-200 80-100 Heat recovery rate (%) 97 97.2 97.5 96 98.7 98 98.2 99 95 Heating temperature (℃) 700-950 700-950 700-950 700-900 700-950 700-900 700-900 700-900 200-300 The inlet temperature refers to the temperature of the part (heating part) that heats the heat pipe. The outlet temperature refers to the temperature of the heat pipe opposite the heating part (condensation part). The heat recovery rate is obtained by measuring the rate of heat delivered from the heating part to the condensation part. The maximum allowable heating temperature is the critical temperature that can be heated to the heating part of the heat pipe as much as possible. .

As shown in Table 2 above, in the case of the heat pipe made using the composition for heat transfer according to the present invention as the working fluid, compared with the conventional heat pipe made using the composition for heat transfer as the working fluid, It can be seen that it is much superior in flow rate and heat recovery rate per area, and also in the maximum heating allowable temperature, it is much higher than the conventional heat pipe, and thus the applicable range is also high.

In the case of a heat pipe made using the heat transfer composition according to the present invention as a working fluid, the heat pipe is made of a wick-free structure, and the heat pipe having the wick has a wick in comparison with the manufacturing unit having a wick of about 1,000 to 2,000 won. The manufacturing cost is about 15,000 to 20,000 won, and in terms of manufacturing cost, a heat pipe using the heat transfer composition according to the present invention as a working fluid is inexpensive. Of course, there is a heat pipe without a wick, but there is a problem that the manufacturing cost is low, but the performance and efficiency are inferior.

As described above, the composition for heat transfer according to the present invention has a high heat transfer rate, a long residual heat time to hold heat, and a low heat loss. In the case of manufacturing a heat pipe using the composition for heat transfer having such characteristics, the manufacturing cost of the heat pipe can be lowered because the performance is sufficiently exhibited even when the heat pipe is manufactured.

Claims (6)

The composition for heat transfer comprising acetone and 80 to 120 ml of isopropyl alcohol with respect to 100 ml of the acetone. The method of claim 1, 60 to 90 ml of distilled water with respect to 100 ml of acetone further comprises a composition for heat transfer. The method of claim 1, The composition for heat transfer, characterized in that it further comprises 70 to 120ml of isobutylaldehyde with respect to 100ml of the acetone. The method of claim 2, The composition for heat transfer, characterized in that it further comprises 70 to 120ml of isobutylaldehyde with respect to 100ml of the acetone. The method according to any one of claims 1, 2, 3 and 4, The composition for heat transfer, characterized in that it further comprises 50ml to 110ml with respect to 100ml of the acetone any one selected from the group consisting of pentane, isopentane and mixtures thereof. The method of claim 5, Capacity ratio of the mixture of the pentane and isopentane ratio 1: 2 to 1: 1, characterized in that the composition for heat transfer.