Analysis Of Flow Characteristics And Structural Stress Of Double Spiral Tube Heat Exchanger

Energy has become an important guarantee for our survival,it is of great significance to improve transfer efficiency of heat-transfer equipment in energy strategy.Heat exchanger is one of the most important and common equipment in heat-transfer equipments,therefore,in the field of scientific research and production application,it has become a focus to improve the heat-transfer efficiency of heat exchanger.In this paper,heat-transfer enhancement of double-pipe heat exchanger is studied,the purpose of heat-transfer enhancement is achieved by increasing the spiral plate in the tube and shell.Through the study of the Nusselt number,friction coefficient,comprehensive heat transfer enhancement factor,and the temperature distribution in the flow field,pressure distribution characteristics,internal and external spiral plate has the influence on heat-transfer law to provide the basis of the double-spiral plate and double-pipe heat exchanger structure design and engineering application.In this paper,a double-pipe heat exchanger is studied,enhancing heat-transfer performance by changing the direction of fluid flow in the tube and shell and increasing fluid turbulence.Reynolds averaging method is used to average fluid basic control equations in double-spiral plate and double-pipe heat exchanger,Reynolds stress turbulence model is used to close fluid control equations,discrete fluid control equation based on the finite volume method.The finite element method is used to analyze the solid structure,establishing contract surface between the fluid domain and solid domain,Iterative coupling method is used to establish computational method of double-pipe heat exchanger.Study on the enhancement of heat transfer method of single shell spiral plate has been establishing,data that is obtained by simulating Nusselt number,friction coefficient under different Reynolds number is compared with experimental ones,the results show that the established numerical model is in good agreement with the experimental and theoretical calculation,the rationality of the simulation method is verified.Study on heat transfer enhancement of double helical tube heat exchanger by using the built model,through the study of the heat exchanger in the single factor(shell pitch,tube pitch,installation angle)changes,the Nusselt number of heat transfer in the heat transfer process,friction factor and heat transfer factor comprehensive strengthening trend,and combined with the results of pressure and temperature nephogram,determine a heat exchanger structure the higher heat transfer enhancement.The heat exchanger structure under different conditions to select the double spiral sleeve type heat exchanger of heat effect change trend,and the structure in the fluid flow for stress analysis of thermal conditions,results show that the structure of the heat exchanger in the location of the maximum stress shell spiral blade,the maximum stress is less than the allowable stress,provide a theoretical reference for practical engineering application of the heat exchanger.Through the above analysis shows that the established numerical calculation modle with reliability,double spiral sleeve type heat exchanger has significantly improved heat transfer effect,we obtained the changing trending of heat transfer of the heat exchanger in the single factor changes,obtained a double spiral sleeve type heat exchanger is better structure.