Two-phase Closed Thermo-sypho Numerical Simulation And Structural Optimization

The well-known long-range thermal conductivity heat pipe has excellent characteristics of thermal conductivity through a small axial section. The application of steel-water heat pipe heat exchanger is relatively common in our country. Heat pipe’s heat transfer enhancement is one of the hot research topics; however, the majority of current research topics of heat transfer performance are mostly around the excellent thermal properties of small axial section of the heat pipe. The literature related to the numerical simulation of heat transfer enhancement of the thermo-syphon is lack of the combination of the proposed field synergy theory. It is lack of the relevant theoretical paper which combined field synergy theory has meta-theoretical character, and do not stick to the excellent thermal performance of the small axial section of conventional heat pipe.The object of the research is the impact of gravity thermo-syphon radial heat transfer performance and combined the field synergy theory which proposed by GUO Zeng-yuan.we proposed a new gravity thermo-syphon structure. Computer numerical simulation technology for heat transfer performance and inner-syphon flow process analysis is an important and indispensable method. Finite element method and theory with existing heat transfer enhancement theory, providing reliable simulation results in order to improve the heat transfer performance of thermo-syphon. The numerical results for quantitative analysis of the heat transfer performance of different structures make reasonable predictions. This paper tried to propose a design scheme and improve the gravity thermo-syphon’s energy efficiency of heat transfer equipment. It combined analysis of flow field inside gravity thermo-syphon and circumferential thermal resistance and is trial to propose an inner-spoiler structure to improve heat transfer enhancement. The turbulence inner-structure is mainly used for radial heat transfer enhancement’s improvement of gravity thermo syphon’s evaporator. The study of this subject reference previous studies and is based on their theory, put forward a new thermal spoiler structure, and seek to propose a new idea of heat exchanger’s thermal strengthening.The issue’s numerical simulations executed FLUENT software’s internal control equation: energy equation, momentum equation, etc. gravity thermo-syphon heat exchanger inner-coupled field numerical simulation included the flow field and thermal field, combined with the field-synergy to study the course of circumferential heat transfer enhancement. We proposed feasible strengthening structure which based on the numerical results of the analysis for the gravity thermo-syphon’s heat transfer enhancement. Research results are simultaneously applied to two patents’ declaration.This paper proposed a new spiral fin spoiler inner-structure, which has two salient features of size, cone angle and helix angle. we proposed a set of comparable parameters for this interpolation tapered inner spoiler two parameters: There is a set of α=12.33°,30°,45°,60° for cone angle, helix angle has β=10.37°,14.036°,25.91°. CFD numerical simulation were compared by two structural parameters’ influence on heat transfer and flow resistance characteristics of thermo-syphon, for the numerical simulation results show the quantitative analysis of different taper: numerical simulation results show that the corresponding cone angle α=60°,and the resistance coefficient hf’s value changes range of 0.013~0.37. 30° cone angle’s resistance coefficient than the 60° cone angle’s increases 0.460~0.592 times. Comprehensive EEC-Re curve, EEC-α curves and turbulent heat transfer performance parameters of working conditions, when cone angle is 30° the model is ideal for strengthening the heat transfer effect. Quantitative analysis of simulation results for different cone angle show: numerical simulation results in enhanced tubes shows EEC maximum value achieved at the helix angle of 25.91°. Comprehensive view of the whole paragraph EEC-Re curve, 25.91° helix angle’s strengthening effect is better. The analysis of EEC-β curve, we can see the strengthening effect of helix angle 25.91° is more desirable. For the inner-spoiler structure, the final selection of the optimal parameters: Cone Angle α=30°, Helix Angle β=25.91°.