Regenerative Heat Exchanger With Phase Change Of The Regenerator

Energy is the material basis of human development, meanwhile, the present severeenergy situation calls for energy conservation and the development of new energy.yet thetechnology of heat accumulation, an effective way of energy conservation, can alleviate theenergy supply and demand contradiction by storing discontinuous, unstable energy fromchemical production and many industrial processes. because of its large energy storagedensity, small temperature variation and easy to control in heat storage etc., heat storagewith Phase change material (PCM) has been the most widely used heat storage technology.to achieve efficient heat storage with PCM, It is necessary to do research for PCM withexcellent properties and heat storage device with good heat transfer performance. based on thestudy of thermal energy storage with PCM, the graduate thesis has proposed a phase changeregenerator with striated groove and finned tube, exploring the influence of its structuralparameters to heat transfer by simulating its heat storage and release performance with Fluentsoftware.The thesis specific contents and conclusions are as follows:⑴Firstly, the thesis introduces the thermal properties of PCM, PCM selection, heat transferenhancement of PCM, and numerical solution method of phase change heat storage. Secondly,the thesis is about the simulation of phase change regenerator, analyzing the heat transfercharacteristics of different structural phase change body and heat-carrying fluid flowcharacteristics. Finally, the thesis discusses the heat transfer influence with the structuralparameters of striated groove and finned tube varied.⑵With the regenerative process of different structural phase change regenerator simulated,the result indicates that:①structure difference does not affect the distribution of flue gasflow rate, distributing like parabola along the center of the flow channel to the sides; and gasvelocity in transverse groove tube fluctuates with pressure drop of3.97times than that of thesmooth tube.②transverse groove strengthen flue gas heat transfer, and flue gas temperaturefrom its outlet is34.4K lower than that of the smooth tube during thermal storage.③thePCM in striated groove and finned tube regenerator melts fastest with the shortest regenerative cycle, and the maximum heat storage capacity. Compared with finned tube,transverse groove tube, and smooth tube respectively, Its complete melting time are reducedby10.7%,28.6%,42.9%.⑶With the exothermic process of different structural phase change regenerator simulated, theresult indicates that:①transverse groove strengthen air heat transfer, and air temperature fromits outlet is14.1K higher than that of the smooth tube during thermal Release.②fins in heatexchange tube strengthen PCM heat transfer, and the PCM in striated groove and finned tuberegenerator solidifies fastest with the shortest exothermic cycle, and the maximum heatrelease capacity. Compared with finned tube, transverse groove tube, and smooth tuberespectively, Its complete solidification time are reduced by7.7%,17.9%,30.8%.⑷With structure parameters of striated groove and finned tube regenerator changed，thesimulation result about heat storage and release process of phase change regenerator showsthat:①fin thickness hardly influences the latent heat storage and release and fluid outlettemperature;②fin height, fin spacing, transverse groove height, and transverse groove pitchhave great impact on thermal storage and release performance of phase change regenerator:the amount of heat flux flowing through the striated groove and finned tube regeneratorduring thermal storage are approximately3.24times,3.64times and5.08times than that of thefinned tube, transverse groove tube, and smooth tube. During thermal release it turns to be1.35times,1.51times,1.70times.