Analysis Of Enhanced Heat Transfer Performance Of Helical Elastic Tube Bundle Vibration Under Different Cyclonic Flow Methods

Restricted by the structural characteristics of the conventional planar elastic tube bundle,the heat transfer volume within the heat exchanger of the same capacity state is relatively small,and therefore the heat transfer efficiency is also relatively small,resulting in poor heat exchanger efficiency.To effectively solve this problem,this paper analyzes the effect of shell process fluid flow and parametric structural parameters on the vibration-enhanced heat transfer characteristics of the helical elastic tube bundle(HETB)in an external combined HETB heat exchanger using a two-way fluid-solid coupling research method.This paper also proposes two heat exchanger improvement schemes,internal structure improvement and external structure improvement,and aims to obtain a heat exchange device with better overall performance through the study of its vibration-enhanced heat transfer characteristics and the comparative analysis of its comprehensive performance.The following is the main research work and summary of this paper.(1)Combining the advantages and disadvantages of shell and tube heat exchangers and casing heat exchangers,a HETB heat exchanger is designed based on the design idea and principle of achieving enhanced heat transfer by fluidic vibration and improving the heat transfer capacity of the heat exchanger.Compared with the traditional elastic tube bundle heat exchanger,the HETB heat exchanger can realize the intensive installation of heat transfer elements,and its internal heat transfer area is larger in the same volume,which has the characteristics of high efficiency heat transfer and stable and reliable operation.(2)The HETB and shell process flow field models are established,the heat transfer characteristics of the HETB heat exchanger in different working conditions are analyzed,the vibration response of the helical elastic heat exchanger element under fluid impulse is analyzed,and the effects of external combination of HETB heat exchanger structure and fluid flow parameters on vibration-enhanced heat transfer and comprehensive heat transfer performance are compared and analyzed.It is shown that the HETB causes fluid disturbance to produce vortex-enhanced vibrations.The vibration generated by fluid impingement is strongest in the vertical plane at the middle.The amplitude of the symmetrically installed elements in the heat exchanger is basically the same,and the frequency of all elements is the same.The flow rate increases from 0.1 m/s to 0.9 m/s,and the heat transfer coefficient per unit pressure drop of the elastic tube bundle decreases by 95.72%,but the heat transfer coefficient increases by 363.84%and the PEC value increases by 78.02%.The number of spiral turns increased from 3 to 7,the heat transfer coefficient of the elastic tube bundle decreased by 10.37%,the heat transfer coefficient per unit pressure drop decreased by 5.45%,the PEC value increased by 2.31%,and the body average heat transfer coefficient increased by 80.80%.(3)The structural improvement of the heat exchanger and the comparative analysis of its vibration-enhanced heat transfer characteristics were carried out in terms of both folded plate cyclonic flow and deflector cyclonic flow.The study shows that the Nussle number of hollow HETB increases by 153.10%,45.55%and 26.73%when the flow rate is increased,and the Nussle number of bending hollow HETB increases by 182.92%,84.22%and 49.05%.At different flow velocities,the vibration increased the hollow HETB Nussle number by 2.13%,1.53%,1.05%and 0.89%;the bending hollow HETB increased by 2.15%,1.42%,0.99%and 0.76%.The heat transfer coefficients per unit pressure drop decreased by 43.63%,24.79%and 20.73%for corotational inflow and 44.01%,28.73%and 18.61%for counterrotational inflow when the flow rate increased.The vibration increases the heat transfer coefficient per unit pressure drop by 11.54%,14.17%,16.32%and 19.07%for the same direction of conduction,and increases 13.29%,15.29%,17.81%and 20.76%for the opposite direction of conduction,respectively.In the range of flow rate from 0.3 m/s to 0.9 m/s,the comprehensive performance of the folded plate cyclonic flow and deflector cyclonic flow heat exchanger decreases with increasing flow rate under the same flow rate,pressure drop and pump power conditions,and the comprehensive performance of the improved cyclonic flow heat exchanger is greater than that before the improvement.Figure[54]Table[10]Parameter[114]...