The Experiment And Simulation Of The Pulsating Flow Of A Small Channel Plate Type Plate Heat Exchanger

Compared with the traditional size heat exchanger,the small channel plate heat exchanger has great advantages in unit volume heat transfer,operation stability,manufacturing cost and service life.With the increasing heat transfer power,people continue to develop the traditional ways of strengthening heat transfer,while trying to explore more efficient ways to enhance heat transfer.The research and engineering application of pulsating flow have been developed as the main branch of fluid mechanics.The phenomena of pulsating flow and its heat and mass transfer are widely used in engineering and biological systems.The pulsating flow can effectively enhance the convective heat and mass transfer in low Reynolds number flow in enhancing fluid mixing and prevent fouling formation,has a unique effect to solve the uneven distribution of fluid,to further improve the performance of heat exchanger is to reduce the flow loss has good application prospects.Based on a lot of theoretical research on our past pulsating flow,the small channel heat exchanger,application research of pulsating flow in a plate heat exchanger,heat transfer to explore pulsating flow in a plate heat exchanger and flow law,provide a theoretical basis for the application of Engineering Technology in the field of plate type heat exchanger for pulse.The main research contents and results are as follows: the main research work is carried out through the combination of experiments and simulation:(1)In order to test the performance of the plate heat exchanger,the pulsating flow test bench was reformed.(2)Through testing system,heat transfer and flow test of small channel plate heat exchanger were carried out,and the heat transfer characteristics,flow characteristics and flow field characteristics were preliminarily obtained.Heat transfer experiments show that the pulsating flow in the process of heat transfer enhancement and weaken the heat transfer coexist,helps to enhance the heat transfer efficiency of pulse frequency f and pulse amplitude A;flow experiments show that low Re conditions,pulsating flow makes flow resistance increased,up to nearly 3 times,at the same time,the increase of F and A it will further increase the flow resistance.(3)From the analysis of the comprehensive energy efficiency index PEC and the energy dissipation angle,the integrated energy efficiency of the pulsating flow heat exchanger at high frequency and high amplitude is improved compared with the steady flow heat exchanger,and the ignition dissipation in the pulsating flow heat exchanger is dominated by the heat accumulation caused by the heat transfer,and the increase of Reynolds number will reduce the heat dissipation of the heat exchanger.visualization experiments show that under different pulsation conditions,vortex flow field in the flow field changed significantly,this should be the internal reasons for the impact of pulsatile flow and heat transfer.(4)On the basis of the experiment,the accuracy of the CFD simulation of the circulation heat and flow process is verified.Get the pulsating flow of fluid pulsating flow disturbance is lead to increase flow resistance and enhance heat transfer;simulation of four kinds of composite corrugated plate heat exchanger of pulsating flow,has been a traditional herringbone pattern compared to more comprehensive heat transfer performance of composite herringbone plate.The pulsating flow small channel plate heat exchanger has certain application prospects in engineering,but it also has shortcomings of increasing resistance.It can reflect the impact of pulsating flow on plate heat exchangers from the comprehensive energy efficiency evaluation.