Preparation Of Enhenced Heat Transfer Pipe Surface Made By Silicone Rubber Membrane And Its Performance Of Heat Transfer

Steam condensation is petroleum chemical industry, power and low temperature gas separation encountered widely in engineering fields phase change heat transfer process.Developing a new type of surface strengthening condensation heat transfer has very important practical value. Commonly,in industry wet steam condensation on the metal surface is often easy to form filmwise condensation. Dropwise condensation is to use the surface tension on the intensification of condensation heat transfer of the most ideal way. The condensation heat transfer coefficient is one order of magnitude higher than filmwise condensation.Experiment was performed by coating-heat treatment of dimethyl silicone oil, silicone rubber membrane,nano silica-silicone rubber membrane dropwise condensing strengthening heat.And studying dimethyl silicone oil, silicone rubber membrane, nano silica in the casting solution on the concentration heat flux, heat transfer coefficient,total heat transfer coefficient, and surface temperature difference of heat transfer.At the same time, dropwise condensing strengthening on the surface were analysed by SEM, FT-IR and contact angle.Experimental results show that experiments preparation the strengthening heat pipe are all achieving dropwise condensation phenomenon. The dimethyl silicone oil condensation heat transfer coefficient than the corresponding filmwise condensation is increased1.1-1.2times. The heat flux is0.78-0.80times of the corresponding filmwise condensation. Carring on the optimization of silicone rubber membrane material. Especially the concentration of4%107silicone rubber heat transfer effect is best. Silicone rubber membranes including uncross-linking,cross-linking,catalytic cross-linking on dropwise condensation heat transfer. It is found that cross-linking within limits is beneficial to the heat transfer.Nano silica in the casting membrane concentration affects the heat pipe heat transfer performance.With nano silica concentration increased, surface water contact angle increases. Nano silica concentration is1%.The heat pipe of surface water contact angle is125.85°. The condensation heat transfer coefficient than the corresponding filmwise condensation is increased3.1-3.3times. The heat flux is1.42-1.44times of the corresponding filmwise condensation. Effect of heat treatment temperature of265℃, the heat transfer is best.