CFD Simulation Optimization And Field Synergy Analysis Of Spiral Tube Heat Transfer Enhancement

Spiral tube heat exchanger has a widely use in industry.The structure of spiral tube is an important factor restricting the heat transfer performance.The excellent design structure can enhance the heat transfer efficiency in the spiral tube and reduce the resistance consumption when the fluid flows.The design of spiral tube structure needs to consider energy loss,flow resistance and uniform heat transfer in the tube.It is of great significance to reduce energy consumption in industry and improve energy efficiency according to the heat transfer effect of different structure design in spiral tube.CFD was used to simulate the heat transfer performance of optical tube,variable diameter helical tube,elliptical and circular spiral tube and rotation angle spiral tube to obtain the temperature distribution in spiral tubes with different structures.First of all,rotation angular spiral tube has the best heat transfer performance.The outlet temperature of 0 degree rotation angle structure is 7.00%higher than ellipse spiral tube.In rotation angle spiral tube,32 degrees rotation angle structure has the best heat transfer performance.The outlet temperature of this structure is 11.68%higher than 0 degree rotation angle structure,19.50%higher than ellipse spiral structure.And the speed and pressure of different structures are simulated,the outlet velocity of 32 degrees rotation angle structure is 20.13%higher than ellipse spiral structure,and it has a uniform pressure distribution.In the analysis of the comprehensive heat transfer performance and field synergy of helical tubes in different structures,the relationship between the number of nusseles,friction factor and comprehensive performance evaluation factor and Reynolds number is calculated.And the fitting formulas and fitting curves of different structures are obtained.The results show that the intensified heat transfer needs to take into account the influence of turbulence intensity and air resistance.In the condition of different velocities,32° rotation angle structure has the highest Nu number,while low f number.Also it has the largest overall ? value and the heat transfer performance is optimal.At the same time,field coordination is simulated to different structures.Simulation results under different flow rates show 32 degrees rotation angle structure has the lowest overall synergy angle and has the best field synergy.