摘要
Shell and tube heat exchangers(STHE)are essential thermal equipment and widely used in daily life.A novel thermosyphon system called falling-film thermosyphon(FFTS)is introduced and integrated into STHE system,resulting in a better thermal performance.In this study,a rectangular solid tube bank of FFTS bundles with a baffle design is studied.The numerical simulation for heat and mass transfer of the FFTS heat exchanger is developed to predict the condensation rate of the vapor in the flue gas,and a lab-scale prototype is also built up in COMSOL.The prediction is validated with the experimental data from references,and the model’s accuracy is verified within 10%-12%error.Also,the Non-dominated Sorting Genetic Algorithm,version 2(NSGA-II)is implemented to improve the thermal performance of rectangular tube banks in this paper.Several parameters,e.g.,baffle number,tube number,and tube space,are optimized.As a result,compact configurations with more baffles are preferred to enhance the performance associated with a high-pressure drop correspondingly.The optimized layout for the lab-scale prototype can increase by 18 to 32%condensation with a pressure loss of less than 200 Pa.
