Columnar fin falling film evaporation heat exchange tube

Abstract

The invention discloses a columnar fin falling film evaporation heat exchange tube. Rectangular columnar fins are uniformly arranged on the outer surface of the columnar fin falling film evaporation heat exchange tube, axial and circumferential grooves are formed by gaps between the adjacent columnar fins, and a flow network beneficial to uniform distribution of liquid is formed; in order to prevent splashing and surface appearance changing generated when liquid in the upper row of heat exchange tube bodies drips to the surfaces of the lower row of heat exchange tube bodies, the tops of the columnar fins are designed to be inclined planes; a plurality of micro inclined grooves are formed in the bottoms of the circumferential grooves, so that wetting angles are increased, the hydrophobicityof the surface is improved through the combined action of the micro inclined grooves in the bottoms of the grooves and the inclined tops of the columnar fins, and the state of the surface reaches theCassie state of the rough surface; and the liquid flow resistance is reduced, the spreading performance of the liquid is improved, the thickness of a liquid film is reduced, a composite boundary jointly formed by solid, liquid and steam can be further formed, the number of gasification cores is increased, and the evaporation heat exchange coefficient is increased.

Description

technical field [0001] The invention relates to a columnar fin falling film evaporation heat exchange tube, which belongs to the technical field of heat exchangers, and is especially suitable for falling film evaporators, including absorbers in absorption heat pump systems. Background technique [0002] At present, the falling film evaporator is widely used in the evaporator of the central air conditioning system, including the evaporator and absorber of the lithium bromide absorption heat pump. On the arranged heat exchange tubes, part of the liquid generates steam through heat exchange with the hot fluid in the heat exchange tubes, and the other part of the non-evaporated liquid will drop radially along the heat exchange tubes to the tubes arranged below. Since the liquid sprayed by the sprinkler and the liquid dripping from the high heat exchange tube are basically in the shape of drops or columns, the thickness of the local liquid film at the dripping place is greater th...

AI Technical Summary

Problems solved by technology

However, when the liquid dripping from a high place hits the surface of the heat exchange tube below, splashing will occur. The splashed liquid either directly drops on the bottom of the heat exchanger through the gap between the heat exchange tubes and cannot participate in evaporation, or is randomly The steam is carried away, resulting in uneven liquid distribution locally, which will seriously affect the heat exchange efficiency of the evaporator; even rushing out of the evaporator will endanger the safety of connected equipment

Images