关键词: 扭曲椭圆管换热器, 壳程传热膜系数, 壳程压降, 综合性能

Abstract:  Heat transfer and pressure drop of twisted elliptical tube heat exchanger with Fr_M=79 are tested in the present work. Based on the experimental result, the application range of previous correlations for twisted elliptical tube heat exchanger with Fr_M>232 and Fr_M=64 is analyzed, and correlations of the tested heat exchanger with Fr_M=79 are derived. The testing result indicates that there exists a change of fluid flowing state when Re_s increases to 8000. Two heat exchangers with similar geometric parameters to the tested one but supported by segmental baffles and rod baffles are designed. Their shell side heat transfer coefficients and pressure drops are calculated with Bell-Delaware method and Gentry’s method, respectively. Heat transfer coefficients and pressure drops of the two designed heat exchangers are compared with the tested twisted elliptical tube heat exchanger. Comprehensive performance of the three heat exchangers is studied. The twisted elliptical tube heat exchanger gives the highest heat transfer coefficient and lowest pressure drop. This type of heat exchanger has the advantages of segmental heat exchanger and rod baffle heat exchanger and will be widely used in the industry.

Key words: twisted elliptical tube heat exchanger, shell side heat transfer coefficient, shell side pressure drop, comprehensive performance