SU1710977A2 - Electric hydrodynamic heat pipe - Google Patents

Abstract

The invention relates to a power system, may be used to create heat exchangers, and is additional to aut. St. No. 861916. The purpose of the invention is to expand the functionality. In the condensation zone 2, a dielectric porous coating 5 is additionally made on the surface of the casing wall, and a perforated high-voltage electrode 6 is above it. The heat pipe design allows heat to be transferred regardless of orientation in space, which expands the functionality of this device. 1 il. g ё

Description

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The invention relates to heat and power engineering, mainly to those areas where electric fields are used to intensify heat exchange processes, can be applied in radio electronics, electrical engineering, chemical technology, etc. and is an improvement of the known device according to the authors. St. No. 861316.

A plate-type heat exchanger is known in which a high-voltage perforated electrode is located opposite the condensation zone.

The disadvantage of this device lies in the impossibility of its operation under the conditions of changing the orientation of the field of gravity and reducing its functional capabilities.

The closest to the one proposed is electrohydrodynamic -. a heat pipe, in which a system of needle electrodes is placed on the heat-exchange surface of the condensation zone, and the heat exchange surfaces of the condensation and evaporation zone are connected to different poles of a high-voltage source.

However, the deterioration of the heat transfer characteristics of the pipe when changing the orientation of the force of gravity reduces its functionality.

The purpose of the invention is to expand the functionality.

The goal is achieved by the fact that in the condensation zone a dielectric porous coating is made on the surface of the housing wall, and above it is a perforated high-voltage electrode, while the coating has a thickness equal to the height of the needle electrodes, and the latter are arranged with a step equal to the distance between their peaks and perforated electrode.

The presence of a dielectric porous material contributes to the retention of condensate on the heat exchange surface, and due to the electric field created by the perforated electrode and needles, it is directed to the heat exchange surface of the evaporation zone. The distance between the perforated electrode and the ends of the needles, smaller than between the electrode and the surface of the evaporation zone, is chosen because of the greater intensity of the electric field near the surface of the condensation zone, which creates favorable conditions for dispersing (transporting) heat-transfer fluid from the condensation zone to the evaporation zone . The limiting distance from the perforated electrode to the evaporation surface is determined by the length of the span of the droplets of the dispersed coolant and depends on the electrophysical properties of the coolant and the intensity of the electric field at the condensation surface. The height of the needles and the distance between them were selected in accordance with the provision of the reliability of the device operation at minimum input voltages (eliminating breakdowns and creating a non-uniform electric field u1 of the condensation surface). Thus, stable operation of the device is achieved when the direction of gravity changes.

The drawing shows a diagram of the electro-dynamic (EHD) evaporation-condensation system (ICS).

The system consists of heat exchanging surfaces of evaporation zones 1 and condensation zones 2, which are connected by a dielectric wall 3. On the inside

the surface of the condensation zone 2 is installed needle-shaped high-voltage .... electrodes 4, placed in a dielectric porous material 5 and on the contrary - high-voltage perforated electrode 6. The dielectric porous material 5 is impregnated with a liquid heat carrier 7.

EHD X works as follows.

With the supply and removal of heat in areas

evaporation 1 and condensation 2, respectively, heat and mass transfer between these zones occurs when the state of the coolant 7 changes. The heat transfer medium 7 from the condensation zone 2 to the evaporation zone 1 is sprayed (dispersed) from the needle electrode f the action of a non-uniform electric field created by perforated 6 and needle k electrodes. Moreover, the non-uniform field draws the liquid heat carrier from the dielectric porous material 5, which prevents its involuntary removal and not getting to the surface of the evaporation zone 1. The presence of needles and dielectric material ensures the creation

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non-uniform electric field that contributes to the reduction of the supplied electric voltage. To exclude the breakdown of the needles A, the diameter of the dielectric porous material 5 is comparable to that of the needles, and the distance between the needles k and the perforated electrode 6 is comparable to provide field inhomogeneities at the ends of the needles k. The perforated electrode is selected to allow the passage of condensate droplets 7 to the heat exchange surface of the evaporation zone.

Compared with the known, the proposed device can operate regardless of the orientation of the gravity force, and the presence of a perforated electrode allows the EHD-X housing to be grounded, which makes its operation safe. In addition, perforated. bath electrode is located significantly

but closer to the condensation zone than the evaporation zone, which reduces the required value of the operating voltage and allows spreading the evaporation and condensation zones to a greater distance.

Claims (1)

Invention Formula Electrohydrodynamic heat pipe according to ed. St. No. 861916, characterized in that, in order to expand the functionality, additionally in the condensation zone, a dielectric porous coating is made on the surface of the housing wall, and a perforated high-voltage electrode above it, the coating having a thickness equal to the height of needle electrodes , and the latter are located with a step equal to the distance between their vertices and the perforated electrode.