Experimental Investigations On Heat Transfer And Resistanct Characteristics Of Shaped Tubes

Using shaped tubes instead of smooth tubes is the most simple but effective way for energy conservation. Experimental investigations on some new types of enhanced tube were carried out in this paper. The pool boiling heat transfer performance on T-Shaped Finned Tube was compared with that on smooth tube. The result showed that the heat transfer coefficient on T-shaped finned tube was 2～3.4 times and 1.7 times that of smooth one when water and ethanol were used as boiling mediums, respectively. Studies for flow boiling heat transfer on internal surface of Internally Grooved Tubes whose corrugation depths were 0.3mm and 0.1mm were carried out, the total heat transfer coefficients were 1.22～1.36 times and 1.12～1.34 times that of smooth tube, respectively. The maximum flow boiling heat transfer coefficient was 2 times that of smooth tube while the maximum export quality was 16% which was 1.45 times that of smooth one. Tests of forced convection heat transfer on Corrugated Low Finned Tubes were accomplished. Heat transfer performances on corrugated low finned tube was compared with smooth tube from the aspects of total heat transfer coefficient, Nusselt numbers and internal heat transfer coefficient, and heat transfer characteristics and resistance ones were obtained. The comprehensive performances were evaluated.