Analysis Of Entransy Dissipation Performance And Optimization Of Flow Heat Transfer In Torsional Heat Exchanger

The energy problem has always been the primary problem in the development of human history,and in the process of energy development,utilization and conversion,the subject of improving the performance of shell-and-tube heat exchangers has always occupied an important position.Based on the existing research on flow heat transfer in the torsional flow heat exchanger,a combination of theoretical analysis was used,numerical simulation and experimental verification,and the mechanism of heat transfer enhancement and flow resistance suppression is further studied by using the theory of entransy dissipation.The structure of the baffle plate is optimized and improved by using the neural network algorithm.Finally,a graphical user interface program is designed,which provides a practical tool for the research work of the torsional flow heat exchanger.The main research contents and results of this paper are as follows:（1）According to the flow characteristics of the shell-side flow field of the torsional flow heat exchanger,a periodic model was constructed,and the numerical simulation calculation results were compared with the overall model.It was found that the flow and heat transfer errors were both within 4%.The reliability of the heat exchanger cycle model provides a more efficient calculation method for subsequent research;（2）The velocity of the shell-side flow field of the torsional flow heat exchanger was experimentally measured by the laser Doppler velocimeter through the flow velocity measurement experimental platform.Compared with the numerical simulation results below,it is found that the error is within 10%,which verifies the accuracy of the numerical simulation results of the shell side flow field of the torsional flow heat exchanger;（3）According to the numerical simulation results of the shell-side flow field of the torsional flow heat exchanger under different working conditions,the convective heat transfer coefficient,pressure drop,performance evaluation index and entropy production were calculated,and compared with the arcuate baffle heat exchanger.In comparison,the study found that compared with the traditional arcuate baffle heat exchanger,under the same working conditions,the convective heat transfer coefficient of torsional flow heat exchanger is lower,the pressure drop is greatly reduced,and the performance evaluation standard is generally better than the arcuate baffle heat exchanger,and under high-quality traffic,the advantages are more obvious;（4）The shell-side entransy dissipation and entransy dissipation thermal resistance of the torsional flow heat exchanger under different working conditions are studied.When the mass flow rate increases,the shell-side entransy dissipation increases continuously,but the entransy dissipation thermal resistance gradually decreases.In the study of the influence of structural parameters of baffles on its transmutation dissipation performance,it is found that the order of influence is the inclination angle,width,group spacing,and longitudinal spacing of the baffle,of which the first three have greater influence,all exceeding 5%;（5）In order to optimize the structure of the torsional flow heat exchanger,the performance of the heat exchanger under the combination of various baffle structural parameters was numerically simulated and analyzed.Taking this as a training sample,an artificial neural network with 2 hidden layers,20 neural units and a regression value accuracy of 0.98 is constructed.The structural parameters corresponding to the final optimization result are the baffle inclination angle of 30°,the width of 95 mm,the group spacing of 106 mm,and the corresponding entransy dissipation and thermal resistance of 1.22×10^-3 K?W^-1,which is 58%lower than the original structure;（6）A program for performance optimization of torsional flow heat exchanger is designed,which enables operators to solve the optimization problem of torsional flow heat exchanger under specified operating conditions,performance indexes and structural parameters according to the existing research data.It provides a practical tool for the research on flow resistance suppression and heat transfer enhancement of torsional heat exchanger.