The Continuous Extrusion Manufacturing Process Of "?"-shaped Axial Microchannel Heat Pipe And The Heat Transfer Characteristics Of Aluminum-Freon-11 Heat Pipe

As a new type of heat pipe heat exchanger efficiency of phase change heat transfer equipment,its application field,in all walks of life in the comprehensive utilization of heat energy and waste heat recovery technology,has played a great superiority.In this paper,combining with the national science and technology support plan project efficient heat exchange device research and development and the low temperature combustion exhaust gas utilization technology development,with the development of high efficiency heat exchange devices to achieve lower zinc pot room temperature indoor environment as the goal.The core components of heat pipe for efficient heat exchange device,the average production method is expensive,and large demand of engineering application.To this,this article puts forward the method of using continuous extrusion equipment manufacturing aluminum heat pipe,in order to reduce heat pipe production cost.In this paper,a shape "?" form micro axial groove aluminum heat pipe were studied,such as micro groove heat pipe,the latest on behalf of the capillary tube,have very strong capillary pump pressure and suction fluid core permeability,show the superior performance of thermal conductivity and temperature performance.And focused on the continuous extrusion production of heat pipe heat pipe technology and heat pipe heat transfer performance test and analysis,design and manufacture of heat exchange device specific research.This paper manufacture heat pipe using the continuous extrusion technology,its process is divided into heat pipe manufacturing both online and offline.Online to make the filling medium at the same time,in the process of continuous extrusion method is simple,the heat pipe manufacturing cost greatly reduced,but the working medium to high temperature mold has the difficulty,done the exploratory work in this kind of method this article;And offline manufacturing is to squeeze out the vacuum heat pipe shell,filling quantitative working medium again,this method is relatively complicated.Compared with the traditional heat pipe manufacturing methods omitted most of the process steps and time.Offline manufacturing technology in this paper,heat pipe manufacturing process was proposed,using tangential continuous extrusion production of vacuum tube manufacturing method,and realizes no need vacuum equipment,also do not need to machining,cleaning,assembly welding and a series of vacuum tube shell before tedious work,subsequent substance filling and sealing equipment is implemented again.This experiment to finalize the design "?" form the axial micro heat pipe,aluminum-freon-11 were studied,the main analysis compared the startup/shutdown characteristics of heat pipe under different conditions,the isothermal property,equivalent coefficient of thermal conductivity and the total thermal resistance,evaporation/condensation heat transfer coefficient,the axial temperature difference.In the laboratory to the heating power and cold source temperature range,the start and closed of the heat pipe has a rapid speed,in the 100 s or so to complete this process;Equivalent thermal conductivity coefficient of the heat pipe is 50?83 kW/(m·?),the highest about copper(398 w/(m-?))of the 208 times;The total thermal resistance is 0.0251?0.041?/W;Evaporation heat transfer coefficient of 1580?2750 W/m2·?,condensation heat transfer coefficient of 3910?7490 W/m2·'C.Heat pipe axial temperature in the range of 3.62?12.48?;Condensation period of outside wall temperature difference(TA-TB)up to 1.5?.Research shows that this medium heat pipe start and closed fast,with the increase of heat flux,because carry,thermal siphon tube temperature and pressure will cause a big wave,phenomenon of volatility.After a concussion,the system back to normal,wall temperature fluctuation is associated with heat flow density and temperature of the cold source.Heat pipe axial working period has uniform temperature distribution.The same amount of liquid condensation section length,short evaporation zone of heat pipe heat transfer performance is better than long evaporation zone.Heat pipe and 30° to the horizontal Angle,the axial temperature difference is minimal,the heat transfer performance is best.Heat pipe under the working condition of the vertical,the same heat load axial temperature contrast changes under different cooling intensity is small,under the cold source temperature 30?,the axial temperature difference is minimal and heat transfer performance of the best.In the same length under different charging rate,liquid rate was 80%of heat pipe heat transfer performance of the best.Finally,this paper adopts the type of micro heat pipe groove,in accordance with the need of Shanghai baosteel zinc pot room cool,the design and manufacture the type gas-liquid type of none adiabatic zone heat pipe heat exchanger,test this type of heat pipe heat exchanger in the heat transfer performance.This type heat exchanger adopts 168 aluminum-freon-11 heat pipe of 1 m in length,according to arrange isosceles triangle fork,heat pipe air side length of 65cm with integral fin,liquid origin tube side length is 35cm.Baosteel zinc pot room thermal power production of 12 kW,the type of heat exchanger heat transfer power rating of 15kW,zinc pot room indoor temperature can be reduced from 40?80? to 35? or so.