Studying On The Heat Transfer Enhancement And Structural Optimization Of Combined Vortex Generators Applied On The Spiral Plate Heat Exchanger

The spiral plate heat exchangers which are widely applied in various sectors areheat transfer devices. The efficiency of heat transfer determines that the level ofenergy is saving or wasteful. Due to the special structure of the spiral channel, theheat exchange air side thermal resistance is90%of the total thermal resistance, whichresulting in heat transfer efficiency is significantly reduced. Longitudinal vortexgenerators are kinds of passive heat transfer enhancement ways, which can saveenergy. theirs effects of heat transfer enhancement are remarkable. Therefore, inrecent years, it has became one of the main trends of the heat transfer enhancement.Therefore, based on it, in this paper, the author put forward to a proposal toinstall combination the vortex generators on spiral plate heat exchanger. The purposeis to improve the air-side heat transfer coefficient, increase the heat transfer exchangerenhanced efficiency and reduce energy loss. In addition, its development and research,in theory, it can enrich the knowledge of the heat transfer, has important academicvalue. In practical projects, it plays a guiding role. It brings new developmentdirection for industrial applications which has practical significance.In the text, the author research the enhanced heat transfer characteristics of theheat exchanger channel with the combination of vortex generators by three methodsof theoretical analysis, numerical simulation and experimental study. The mainlyworks are as follows:(1)Combined with the relevant basic theories of fluid mechanics, heat transferscience and higher heat transfer science, analyzing the conditions of vortex generated;Then, respectively from the boundary layer theory and the field synergy principle twoaspects to analyze vortex strengthen heat transfer mechanism, determine thecomprehensive judgment method of heat transfer enhancement. (2)Synthesize domestic and foreign research results, summarize and analyzethem to determine the form and basic parameters of spoiler. In the text, Usepro/Engineer5.0to establish the physical model, the Gambit2.1software to meshgrid; In the Fluent software solver, setting the boundary conditions, selecting controlequation and determining each of the physical parameters of the medium, then forcalculation model to carry on numerical simulation, research effect of differenttriangle wing attack angle α, elliptical cylinder attack angle β and combined distance son spiral channel heat transfer performance to obtain heat transfer regular pattern.Then select the orthogonal experimental design method to obtain optimized structureand combination.(3)On the basis of the numerical simulation: contrast the optimized structure andthe general structure of the heat exchangers model, to verify the accuracy of thenumerical simulation results.Synthesize the research results which showed that: under the range of Rebetween4000to7000, with the Reynolds number Re increasing, Nu are increased, fare decreased. In the three influencing factors, combined distance s has the greatestimpact on the heat exchanger, triangle wing attack angle α followed, ellipticalcylinder attack angle β has the least impact. When the combined distance s is90mm,triangle wing attack angle α is45°, elliptical cylinder attack angle β is45°, theexperimental indicator G is the highest, so it proved that the combination is theoptimized structure, the heat transfer enhancement effect is best. Through theexperiment to compare the optimized structure with the conventional heat exchangerstructure, the data shows that the optimized structure can significantly improve theheat transfer intensity and the average total heat transfer coefficient is improved at arange of23.2%-30.8%.In the range of allowable error, the experimental results andthe numerical simulation results are consistent, which achieved the desired effect.