Outer Tube Condensation Heat Transfer Coefficient Of The Prediction And Experimental Determination

Due to the energy crisis which happened all over the world, countries have called for energy conservation. Thermal power plant is the major energy consumer of power industry.Improving heat transfer mode of condenser steam condensation in the condenser is one of the effective way to save energy.Coagulation mode can generally be divided into two types: film condensation and beaded condensation. Due to the reduced heat transfer area and lower equipment costs, the latter one was regarded as an efficient way of heat transfer. Therefore, a small experimental plat which is of high air tightness was designed and constructed, non-film condensation heat transfer characteristics of pure working medium(water vapor) and mixed working medium(water and alcohol) Marangoni filmwise condensation heat transfer characteristics was studied. Nusselt(Gnielinski) correlation was used to analysis the wall temperature, then the outside wall temperature of tube was determined by using single hole method and double hole method. Finally, we compared three methods to calculate the heat transfer coefficient outside the tube and analyzed the experimental error.The experimental results indicate that: condensation heat transfer coefficient is independent of the alcohol concentration, but there is an optimum concentration of alcohol. In the vicinity of the optimum concentration range, heat transfer coefficient presents a high value.Moreover, the error of heat transfer coefficient between theoretical results and experimental results varies from-40% to +50%. Taking into account of the large error, experimental error under two different test methods was compared to verify the reliability of the experimental system. The results show that the error range meet the error requirement well by-20% to +20%. Thus we can say the experimental system is of great reliability, so does the experimental data. For improving heat transfer mode of condenser steam condensation in the condenser,this article is of great guiding significance for its promotion and application.