SU1682746A1 - Thermosiphon - Google Patents

Abstract

The invention relates to heat engineering and can be used in heat transfer. . -. heating elements of heat exchangers. The purpose of the invention is to increase the operational reliability of the thermosyphon. A circulating insert 4 is coaxially mounted in the housing 1 of the thermosyphon. In the evaporation zone 2, a coaxial chamber 5 is additionally placed on the housing. The insert 4 has a gap at the location of the chamber 5, and the housing 1 is perforated. At the same time, the ends of insert 4 at the point of rupture are brought into chamber 5. During the operation of thermosyphon, the heat transfer fluid film flowing out of the perforation holes is carried by steam up along the inner surface of the wall of the housing 1. It evaporates and cools the wall of the housing 1 in the upper part of the evaporation zone preventing overheating and destruction of the housing wall 1. 1. v fa fe

Description

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The invention relates to heat engineering and can be used as heat transfer elements of heat exchangers.

. The purpose of the invention is to increase the operational reliability of the thermosyphon.

The drawing shows the described thermosyphon section.

The thermosyphon comprises a housing 1 with zones 2 and 3 of evaporation and condensation, respectively.

The entire length of the housing 1 is coaxially mounted with a circular insert 4, and over a portion of the length of the housing 1 in the evaporation zone 2, there is a heat-insulated chamber 5. In the zone of the chamber 5, the insert 4 has a break and its ends are brought into the chamber 5. At the same time, the housing 1 is lower than the The gap is perforated and through the perforation holes 6 communicates with the cavity of chamber 5.

The location of the chamber 5 on the housing 1 in the evaporation zone 2 is determined by the operating conditions and the geometric dimensions of the thermosyphon. The total flow area of the calibrated holes 6 in the thermosyphon body is less than the flow area of the circulation insert 4 and is selected from the condition of creating a stock of heat transfer fluid in the chamber 5 at a level that ensures stable circulation through the inlet opening of the circulation insert 4 and providing a continuous evaporating film of the heat transfer fluid the inner surface of the housing in the upper part of the evaporation zone 2. Thermosiphon works as follows.

The vapor formed in the process of boiling the heat transfer medium in the evaporation zone 2, through the annular channel formed by the casing 1 of the PTM and the circulation insert 4, enters the zone 3, where it condenses. As a result of complete condensation of steam, the condensate enters the upper part of the circulating insert 4 and through the outlet in the place of rupture merges into the chamber 5, where it collects and then through the inlet of the insert 4 in the place of rupture enters the lower part of this insert 4, through which it returns to zone 2 evaporation.

The natural circulation in the thermosiphon circuit occurs due to the fact that the densities of the coolant in the evaporation and condensation zones are different, and this difference in the values of the densities of the coolant creates a moving head under the action of gravitational forces.

At the values of the supplied heat load much less than the critical return of condensate from the chamber 5 to the evaporation zone 2 occurs through the holes 6 in the form of a liquid film flowing along the inner surface of the wall of the housing 1 of the thermosyphon. When the heat load increases, supplied to zone 2, the flow rate the heat carrier pair increases, and when a critical value is reached, which is characterized by the value of the Kutateladze stability criterion, 2,

The phenomenon of inversion (tilting) film flow. The heat transfer fluid film that flows out of the openings 6 is attracted by steam upward along the inner surface of the wall of the housing of the thermosyphon and, evaporated,

5 cools the wall of the housing 1 in the upper part of the evaporation zone 2, thereby preventing overheating and destruction of the wall of the housing 1 in the upper part of the zone 2.

Thermal insulation of chamber 5 prevents

0 to the boiling of the coolant in chamber 5 and contributes to the creation in it of the stock of the cooled coolant.

Since the cooling of the wall of the evaporating film of the heat-transfer fluid is sufficiently effective, the wall of the casing in the suction area is reliably protected from overheating.

The thermo-siphon form of the invention, comprising a casing with evaporation and condensation areas and a coaxially circulating insert installed in it, which, in order to increase operational reliability, outside the casing in the evaporation zone, the coaxially installed 5 wherein the circulating insert has a break and both ends of the insert are inserted into the chamber at the break point, and the casing below said break is perforated.

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Claims (1)

Claim A thermosiphon containing a housing with evaporation and condensation zones and a coaxial circulation insert installed in it, characterized in that, in order to increase operational reliability, a heat insulation chamber is coaxially installed outside the housing in the evaporation zone, in the area of which the circulation insert has a gap and both ends of the insert at the rupture point are inserted into the chamber, and the body below the gap is perforated. from;