SU779798A1 - Heat exchange element - Google Patents

Description

The invention relates to heat-exchange elements and can be used in evaporative heat-exchange cooling systems of electronic equipment;

Known heat transfer elements with a layer of fine particles from the heat transfer surface of the element £ 1].

The disadvantage of these elements is the lack of heat transfer. when boiling a liquid under reduced pressure and with a wide range of changes in specific heat fluxes.

The purpose of the invention is the intensification of heat transfer during boiling of a liquid under reduced pressure and with a wide range of flow changes.

specific heat by the fact that a thin layer with a hydrocoating is heat deposited, it is full of material, with phobic properties, getinax is made with a thickness of 0.005 O, 01 mm, and fine-grained particles are made of fluorine grains with a nominal diameter of 0.5-2.0 mm.

The drawing shows a heat exchange element. ''

Element 1 contains a layer of fine-grained particles 2 from the side of the heat-transfer surface of element 1. A thin-layer coating is also applied to the heat-transfer surface. 3 from a low-heat-conducting material, and a layer of fine-grained particles 2 is placed on the surface of the coating 3 and is made of a material having hydrophobic properties.

The layer of particles 2 is held at the surface of the element 1 with a thin metal mesh 4.

The bunch of elements 1 can be loaded into a container 5 with a heated fluid, equipped with a tube 6.

to be a steam-venting panel, a surface-giving coating of low-heat-conducting material is achieved, and a layer of fine-grained particles is placed on the surface of this coating and

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Coating 3 in this case is made of getinax with a thickness of 0.005-0.01 mm, and fine-grained particles 2 are made of fluorine grains with a nominal diameter of 0.52.0 mm.

The element works as follows.

The cooled medium circulating inside the element transfers heat through its walls to the heated liquid, which evaporates it cools the element 1, and the formed vapor is removed through the nozzle 6. In this case, a thin layer of low-conductivity coating 3 reduces the amplitude of temperature fluctuations on the heat-transfer surface of element 1 arising on it. specific heat fluxes. This leads to an increase in the maximum specific heat flows. Fine-grained particles 2 of a hydrophobic material located in close proximity to the heat-transfer surface of element 1 contain stable centers of vaporization and reduce the energy barrier of the liquid-vapor phase transition, thereby reducing the temperature head at which the heated liquid boils and increases the heat transfer coefficient in the bubble mode boiling. Particles 2, being in a dispersed state, do not impede the free removal of vapor formed on the surface of element 1.

The invention allows to intensify heat transfer during boiling under conditions of reduced pressures and in the range of changes in specific currents.

Claims (2)

77 Coating 3, in this case, is made of getinaks, which is 0.005-0.01 mm long, and fine-grained particles 2 are made of fluoroplastic grains with a nominal diameter of 0.52.0 mm. The element works as follows. The fluid circulating inside the element transmits heat through its walls to the heated fluid, which evaporates cools element 1, and the resulting vapor is removed through nozzle 6. At the same time, a thin layer of low thermal conductive coating 3 reduces the amplitude of temperature fluctuations to the heat transfer over: Element 1 no. q on it at high specific heat fluxes. This leads to an increase in the maximum heat output. The fine-grained particles 2 of hydrophobic material, which are in close proximity to the heat transfer properties of element 1, contain stable centers of vaporization and lower the energy barrier of the liquid-vapor phase transition, which results in a decrease in the temperature difference at which the heated liquid boils and the heat transfer coefficient increases in bubble boil mode. Particles 2, being in a dispersed state, do not interfere. They allow the free removal of steam formed on the surface of element 1. 8 The invention allows to intensify heat transfer during boiling under conditions of reduced pressure and at a wide range of variation of specific heat fluxes. Claim 1. Heat exchanger element with a layer of fine-grained particles on the side of the heat transfer surface of the element, characterized in that, in order to intensify heat exchange during boiling of a liquid under conditions of reduced pressure and over a wide range of variation of the specific heat flux of the 1 x streams, a thin layer coating is applied to the heat transfer surface from low heat conducting material,. and a layer of fine-grained particles is placed on the surface of this coating and is made of a material with hydrophobic properties. 2.Item pop. 1, it is also distinguished by the fact that the coating is made of getinaks with a thickness of 6, -005-0.01 mm, and fine-grained particles are made of fluoroplastic grains with a nominal diameter O, 5-2.0 mm. Sources of information taken into account during the examination 1. Patent of England No. 125630О, cl. F4 S, pub. 1968. 1111 II 11 and II g ij 11 II 1 and If in J njTJjmj jptftftf / J Y /////./ 7/7 y / y // q-Mif-hffiqj /////////////////// y ///////// // ///