Research On Prediction Methods For Two-Phase Flow Boiling Heat Transfer Inside Enhanced Tubes

The heat exchanger's iniaturization and the energy conservation have promoted the development of the two-phase flow boiling heat transfer inside enhanced tubes.Micro-fin tubes and tubes with twisted tape inserts are widely used in heat exchanger equipment.Due to its complicated internal mechanism,the flow boiling heat transfer correlations and frictional pressure drop correlations used in engineering still have many problems.In order to improve the predition accuracy of heat transfer coefficient and frictional pressure drop to provide reference for design and application of heat-exchange equipments and avoid under-design or over-design of related equipments,the main contens of this paper is the research on prediction methods for two-phase flow boiling heat transfer inside enhanced tubes.5 existing flow boiling heat transfer correlations and 5 flow boiling frictional pressure drop correlations for tubes twisthd tape inserts are collected and reviewed,508 heat transfer coefficient experimental data and 977 frictional pressure drop experimental data are abtained,the reviewed correlations are evaluated against the experimental database.A new heat transfer correlation and a new frictional pressure drop correlation are proposed,which show better predition accuracy.15 existing flow boiling heat transfer correlations and 10 flow boiling frictional pressure drop correlations for micro-fin tubes are collected and reviewed,3482 heat transfer coefficient experimental data and 1160 frictional pressure drop experimental data are abtained,the reviewed correlations are evaluated against the experimental database.A new heat transfer correlation and a new frictional pressure drop correlation are aproposed,which show better predition accuracy.Herringbone micro-fin tube is a new kind of mic-fin tube in recent years,there is no correlation proposed for the predition of heat transfer coefficient in herringbone microfin tube,505 heat transfer experimental data points of herringbone micro-fine are collected,and 15 heat transfer correlations of mic-fin tube are evaluated against the herringbone micro-fine experimental data.A new heat transfer predition correlations is proposed for herringbone tubes.A plate-finned-tube evaporator simulation software is developed with Matlab and GUI,the impact of the selection of heat transfer tubes and heat transfer prediction correlations for the evaporator design are compared.