Thick "Ω" Heat Pipe Technology Research Shaped Micro Channel Continuous Aluminum Extrusion

As an energy efficient heat exchanger components, aluminum heat pipe with thick-walled micro-grooves can be used in the manufacture of entirety rolling spiral finned pipe which does not exist contact thermal resistance and greatly improve the heat transfer efficiency. Finned heat exchanger which made by it are widely used in metallurgy, chemical industry and other fields of cooling and residual heat recovery. Compared with ordinary heat pipe, heat pipe with "Ω" shaped micro-grooves has several advantages such as small radial thermal resistance, high heat transfer coefficient and easy to machining. Traditional production methods for micro-grooves heat pipe is spinning, broaching and conventional extrusion, due to a long process, high cost, low efficiency, the traditional method no longer meet the needs of modern production. Since the process is simple, high raw material utilization, low energy consumption, less investment, CONFORM technology will gradually replace the traditional heat pipe production methods, using the CONFORM technology can achieve extra-long, continuous, stable micro-grooves aluminum heat pipe production.According to the heat pipe theory which based on Cotter theory, combined with the specific using conditions and working requirements, as well as the forming feasibility of continuous extrusion, design of thick-walled micro-grooves heat pipe structure and size. Determine the shell material is aluminum alloy1060; consider aspect of permeability, effective capillary radius and heat transfer performance, choose "Ω" shaped axial micro-grooves as the heat pipe wick structure, and the narrow gap width of the porous wick reached0.3mm; from the point of view rolling efficient heat transfer spiral fin,choose the heat pipe wall thickness of4.5mm; narrow gap height porous wick, capillary core diameter, the diameter of the vapor chamber, the number of micro-grooves and other heat pipe parameters were determined.Die structure used in tangential continuous extrusion for producing aluminum heat pipe with thick-walled "Ω" shaped micro-grooves was designed and optimized, by improving the female die angle, hinder flow angle, sizing zone, mandrel shape and length and other integrated method, to solve the problems of uneven metal flow,"Ω" shaped micro-grooves difficult forming, the mandrel teeth easily to broken; and proposed a new combined connection structure of the male die and mandrel, which can easily removal and replacement of the mandrel by using screw assembly the male die. The final experiment results show that the improved die structure has good formability.According to extrusion processing characteristics of the aluminum heat pipe with thick-walled "Ω" shaped micro-grooves, determined the main process parameters, such as running clearance, extrusion speed and temperature, extrusion boots clincher pressure and mold cavity preheating temperature. Conducted a comprehensive analysis of quality defects such as scratches, foam (stomata) and draw bead which exist continuous extrusion process, put forward the corresponding process solutions, and pointed out that the extrusion process parameter control and precise die design and machining make a major impact on the quality of the product. In addition, finally there is a ponder and outlook about application prospect of continuous extrusion forming the aluminum heat pipe with thick-walled micro-grooves.