EXPERIMENTAL STUDY OF HEAT TRANSFER AND RESISTANCE CHARACTERISTICS OF SINGLE H-TYPE AND DOUBLE H-TYPE FINNED TUBES

There are various finned tube heat exchanges with diverse thermo-flow performance being widely applied in the power plants. Wherein, the H-type finned tubes are widely used in the economizer to improve the waste heat utilization efficiency of the coal fired boiler. The experimental studies regarding the heat transfer and resistance characteristics of single H-type and double H-type finned tubes have obtained the thermo-flow performances under different conditions. In addition, the test facility of double channels is specially designed to ensure the test accuracy. Correlations for Euler number Eu, Nusselt number Nu and Performance evaluation index PEc with Reynolds number Re are presented by analyzing the thermo-flow performances of the used bundles. The results show that the single H-type finned tube performs better heat transfer characteristic and relatively worse resistance characteristic than the double H-type finned tube. Consequently, the double H-type finned tube is recommended in the practical application considering the higher manufacturing installation efficiency. (CSPE)