Correlation for boiling heat transfer on porous surfaces tubes

摘要

The paper treats the method of decreasing the size of surfaces of heat exchangers in general by increasing the heat transfer coefficients, the importance of heat transfer enhancement in general and for vaporization in special, also the used methods. This increase is achieved in our case by passive methods applied to heat transfer surfaces, namely depositing metallic porous layers, made using welding methods. These tube surfaces are used for increasing heat transfer coefficients from inner heating source to outer vaporizing liquids. Are mentioned also the most important particularities for vaporizing enhanced heat transfer from metallic porous layers. Results for tests made with improved heated surfaces, comparison between different surfaces are presented after personal research. Is proposed specific heat transfer correlation and results obtained with it compared with other researchers' results. Are described the way of establish and the correlations that could be used in the work of design for heat exchangers which are to be made with tubes having the described and used types of surfaces.