SU1763852A1 - Heat pipe - Google Patents

Description

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(21) 4897046/06

(22) 12.27.90

(46) 09/23/92. Bul No. 35

(71) Scientific and Production Association Energia

(72) V.L. Losev, G.E.Kelin, M.V.Sigal and V.N. Boryskina

(56) USSR author's certificate No. 1027501, cl. F28 D 15/02, 1982.

USSR Author's Certificate No. 851084, cl. F 28 D15 / 02, 1979. (54) HEAT PIPE

(57) Use: in heat transfer devices. The essence of the invention: in case 1, the coaxiality is installed with

formation of a gap insert 4 in the form of a perforated cone 12. Insert 4 is equipped with a screw fin 5. The latter forms a screw channel. A perforated partition 7 with a hydrophilic porous coating 8 is installed in the gap. The latter is in contact with the fins 5. The cone P is provided with a hydrophobic porous coating 13. The cap 9 is formed at the border of the transport and condensation zones with the formation of chamber 10. The chamber 10 is in communication with the evaporation zone through condensate lines 11. The output ends of the condensate lines 11 are located below the level of the coolant. 1 il.

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The invention relates to a power system, namely to heat transfer devices.

A heat pipe is known, comprising a housing partially filled with a coolant with condensation and evaporation zones, concentrically mounted inside the housing with the formation of a screw channel insert with helical fins on the outer surface (1).

A heat pipe is known, adopted as a prototype and containing a cylindrical body with evaporation, condensation and transport zones, in the latter of which with a gap in relation to the body an insert is installed, equipped with a screw outer finning, forming a screw channel in said gap

(2).

The disadvantages of these devices are the low thermodynamic efficiency of the condensation process, as well as the low heat transfer characteristics due to the poor quality of the separation of the liquid phase of the coolant. Indeed, during operation of heat pipes, individual droplets of the liquid phase of the coolant pick up with steam and are transferred to the condensation zone. The thickness of the condensate film increases and the thermal resistance increases.

The aim of the invention is to eliminate these drawbacks, namely: to intensify the condensation process and increase the heat transfer capacity by improving the separation of the coolant phases.

This goal is achieved by the fact that in the aforementioned gap between the transport and condensation zones, a plug is installed to form a chamber in communication with the evaporation zone through at least one condensate line whose inlet end is located in the plug zone, and the output end is below the coolant level in the evaporation zone, the insert is made in the form of a perforated cone, with its tip facing the evaporation zone and provided outside with a porous coating of a hydrophobic material, and in the gap between the casing and the insert in the contour A plug with a coaxially installed longitudinal cylindrical perforated insert, which forms a fluid channel with the housing and is provided with a porous coating of hydrophilic material in contact with the insert finning.

The drawing schematically shows a longitudinal section of a heat pipe.

The heat pipe contains a hermetic case 1 partially filled with a heat carrier with zones 2, 3 of condensation and evaporation. Inside the housing 2 is installed with

the formation of the screw channel of the floor insert 4 with spiral fins 5 on the outer surface. A cylindrical perforated partition 7 is installed between the body 1 and the insert 4 to form a channel 6 for the passage of the liquid phase of the heat transfer fluid. condensate collection chamber 10. The chamber 10 is hydraulically communicated via the condensate pipeline 11 with the evaporation zone 3 below the level of the heat transfer medium. The insert 4 is made in the form of a perforated cone 12 with a hydrophobic porous coating 13 on the side of the spiral fin 5, the top of which is directed to the evaporation zone 3.

Heat pipe works as follows.

When heat is applied to the evaporation zone 3, the coolant is heated and, by evaporation, enters the screw channel gradually.

a diminishing width formed by the spiral fins 5 and side surfaces of the hydrophobic and hydrophilic coatings of the cone 9 and the partition 6, in which the flow is curled and

complete phase separation. The liquid phase of the coolant is discarded on a perforated partition 7 with a hydrophilic porous coating 3, into the vapor phase it moves near the perforated cone 12

with a hydrophobic porous coating 13. In this case, the liquid phase gradually passes through the permeable wall 7 with a hydrophilic coating 8 and through the channel 6 enters the evaporation zone. Steam phase

the coolant passes through the perforated cone 12 permeable to it with a hydrophobic porous coating 13 and enters the condensation zone 2. The condensate formed in the condensation zone 2 drains

into the condensate collection chamber 10, from where it flows through the condensate lines 11 to the evaporation zone 3 under the level of the coolant.

Placing the cone 12 and the partition 7 against each other by surfaces with hydrophobic and hydrophilic coatings 13, 8

and making the insert in the form of a cone 12 with a plug 9 allows for an increase in the productivity and completeness of the separation of the vapor-liquid mixture.

The use of a cylindrical perforated partition 7 and a perforated cone 12 reduces the thickness of the hydrophilic porous coating 8 and the hydrophobic porous coating 13 by stiffening them and, consequently, reducing their hydraulic resistance.

As the hydrophilic porous coating 8, for example, a fine mesh can be used, which can be folded into several layers to reduce the average size of the holes, pressed and sintered. The hydrophobic porous coating 13 can be made, for example, of fluoroplast, polyethylene, and the like.

The technical and economic effect when using a heat pipe arises due to the effective capture of droplets of the liquid phase of the coolant from the rising vapor-liquid flow, which leads to an intensification of heat transfer.

Claims (1)

Invention Formulation Heat pipe containing a cylindrical body with evaporation, condensation and transport zones, in the latter of which with a gap in relation to the housing, an insert is fitted with a screw outer finning, forming a screw channel in said gap, characterized in that, in order to increase the heat transfer capacity by improving the separation of the coolant phases and intensifying the condensation process, between transport and condensation zones a stopper is installed with the formation of a chamber in communication with the evaporation zone by means of at least one condensate line, the input end of which is located in the stub zone and the output end is below the level of the coolant in the evaporation zone, while the insert is made in the form of a perforated cone, vertex-facing to the evaporation zone and provided externally with a porous coating of hydrophobic material, and in the gap between the case and the insert, in contact with the cap, a coaxially installed longitudinal cylindrical perforated insert, forming with the case liquid channel and provided with a porous coating of hydrophilic material in contact with the insert fin.