RU2306494C1 - Heat accumulating device - Google Patents

Abstract

FIELD: heat engineering.

SUBSTANCE: device comprises housing provided with spaces filled with the heat-accumulating agent made of a special composition material.

EFFECT: reduced mass and sizes and enhanced efficiency.

2 cl, 2 dwg

Description

The invention relates to the field of heat engineering, and more particularly to heat storage devices using the latent heat of phase transitions of the working substance to provide the required thermal regime of energy sources (IE) during their cyclic operation, and also as their protection against short-term effects of external heat flows.

Thermal storage devices provide the thermal regime of electronic equipment (CEA). To accumulate heat in them, along with the heat capacity of the design of the device case, reversible endothermic processes of melting of working substances are used, accompanied by additional heat absorption during phase transformations of these substances from solid to liquid after they reach the phase transition temperature. Such devices, as a rule, are thin-walled metal containers of finite geometric dimensions with a smooth or ribbed surface, the hermetic volume of which is filled with a consumable working substance [1] p.6, [2] p.20-25, [3] p.33- 36.

After the CEA is completed or the exposure to peak external heat fluxes ceases, the working substance cools and solidifies as a result of heat exchange with the environment. The time between repeated starts of REA should be such that the working substance has completely hardened by the beginning of the next cycle of turning on the equipment. The melting working substance in the device is located in containers or cavities that must be airtight to prevent the molten mass of the working substance from spilling out of them. Typically, the tank is made of a metal casing with high thermal conductivity (most often from aluminum alloys), and the IE or the entire unit with REA are placed outside or inside the tank.

Due to the fact that the working substance changes its volume during operation, the device should be provided with appropriate compensation for changes in volume using an elastic membrane, bellows, or by filling the volume with superheated liquid, if the structure is sufficiently rigid and practically does not change its volume when heating and cooling. With a rigid structure of a metal container (or cavity), refueling is carried out at the maximum temperature of the liquid working substance, which it can achieve during operation. Therefore, after the solidification of the substance, as well as at low temperatures of the liquid phase, a gas cavity will form inside the volume, which impairs heat transfer.

A known design of a heat storage device, the sealed housing of which is made in the form of a radiator made of an aluminum alloy filled with a melting working substance (in this case paraffin) [1] p. 71-72. With this design, heat is removed from semiconductor devices.

Closest to the proposed invention is the design of a heat storage device based on a phase transition working substance, which is a case filled with a sodium tank, divided into several sealed compartments with a flat base, which serves as a heat receiver when the electronic unit is placed on it with good thermal contact (USA, patent No. 3238642, class 361/705, 1964).

The main disadvantages of the above structures are:

- the need for sealing and, as a result, the complex manufacturing technology of such heat-storage devices, which leads to a deterioration in the mass and size characteristics of equipment operating in peak switching modes and a decrease in reliability;

- the presence of gas areas in the internal cavities of the structure, impairing heat transfer.

The objectives of the invention are to reduce the mass of the heat storage device, simplify the technology of its manufacture, improve heat transfer, ensure stable operation of the device due to the refusal to seal the case.

The technical results of the present invention are

- improvement of overall dimensions, which is especially important for on-board equipment;

- maintaining a constant value of enthalpy from cycle to cycle;

- increased reliability.

These technical results are achieved by the fact that in the known heat-storage device containing a housing having cavities filled with a heat-storage phase-transition working substance, a composition of a form-stable material is used as a working substance, in which the phase-transition substance does not follow from the volume of this material after melting and being in a liquid state during overheating, communicating with the environment. The housing of the heat storage device can be made in the form of a honeycomb or in the form of a radiator.

The use of a form-stable phase-transition material (FPM) eliminates the need for sealing the casing, which facilitates the design and reduces its dimensions, and also avoids the degrading heat transfer of gas regions in the cavity of the casing. Thus, stable operation of the heat storage device is ensured.

Examples of the proposed device are illustrated by the drawings shown in figures 1-2.

Figure 1 shows a General view of a heat storage device with an energy source mounted on a housing made in the form of a honeycomb;

figure 2 shows a diagram of a heat storage device with an energy source mounted on a housing made in the form of a radiator.

Figure 1 shows a heat storage device with an energy source 1 mounted on a housing consisting of two panels 2, between which there are honeycombs 3 filled with a form-stable FPM 4 in contact with the environment. Compositions of components that provide the required endothermic effect, the value of the phase transition temperature of the melting working substance and its high shape stability in a given temperature range of the device on which the energy sources are installed can be used as form-stable FPMs (for example, to ensure the thermal regime of electronic equipment). If we assume that the ambient temperature does not exceed 50 ° C, and the maximum allowable temperature of energy sources can be in the range from 80 to 150 ° C, then the choice of a melting working substance is determined based on these conditions. Therefore, for cooling devices during sessions of cyclic IE, you can use, for example, a form-stable heat-storage material with a melting point of the phase transition component exceeding the maximum ambient temperature. For low-temperature devices, the composition of the heat-accumulating material made according to RU patent No. 2190656 dated June 8, 2001, the stabilization temperature of which is reached at values of 50-55 ° C with a high total thermal effect and maintaining the strength properties and shape stability of the material, is currently most suitable.

Figure 2 shows another embodiment of a heat storage device with an energy source 5 mounted on a housing 6, the cavities of which are filled with a form-stable FPM 7 in communication with the environment. As FPM, the composition according to patent RU No. 2190656 of June 8, 2001 can be used.

The device operates as follows.

The housing and the FPM in contact with it are heated by the heat received from the IE. When the melting temperature in the parietal layers is reached, the MTF begins to melt. Heat transfer to the internal volume of the FPM is carried out by thermal conductivity. Upon melting, the FPM absorbs an amount of heat equal to the energy intensity of the FPM during phase transition and heating, while the solid and liquid phases are in the volume of the FPM. The phase boundary is mobile, changing in time.

When the IE is turned off, the FPM cools and hardens due to the transfer of heat from the IE and the housing to the environment for a longer period of time. In this case, the amount of heat absorbed by the heat storage device during the operation of the IE is released.

Used sources

1. V.A. Alekseev. Cooling of electronic equipment using melting substances. Ed. A.V. Revyakina, M .: Energy, 1975.

2. S.P. Nechepaev, V.V. Buchok. Development of the design of a small REA unit and its cooling system based on a melting substance. - J. Questions of radio electronics. Series: General issues of radio electronics (Thermal conditions, thermostating and cooling of electronic equipment), issue 12, 1987.

3. I.A. Zelenev, A.F. Klishin, V.M. Kovtunenko, A.F. Shabarchin. Methods for ensuring the thermal regime of automatic interplanetary stations "Venus" in the atmosphere of the planet. - J. Space Research, T.XXVI, Issue 1, Moscow: Nauka, 1988.

Claims (3)

1. A heat storage device comprising a housing having cavities filled with a heat storage phase transition working substance, characterized in that a composition of a form-resistant material communicating with the environment is used as the working substance. 2. The heat storage device according to claim 1, characterized in that the housing is made in the form of a honeycomb. 3. The heat storage device according to claim 1, characterized in that the housing is made in the form of a radiator.

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