Research On Heat Transfer Enhancement Characteristics And Safety Of Autorotational Rotors

Energy is the motive power of human survival and development, In theenergy use process, more than80%of energy conversion process is achievedby heat transfer process or heat exchanger. From the situation of our country,the per capita possession of resources and energy utilizing efficiency isconsiderably lower than other developed countries. So it is the main task ofour country to saving energy and using energy with high efficiency. Heatexchanger is the key equipment of industry in energy transformation,increasing its efficiency is the top priority of all tasks.This thesis firstly presented heat transfer mechanism of heat exchangersand then theoretically studied the heat transfer enhancement technology. Theexisting technology of heat transfer enhancement on tube side was alsointroduced with its relative merits analyzed, which was drawn for futurestudies. On this basis, an experimental system has been designed andconstructed for the research of heat transfer enhancement; meanwhile, bycomparisons between plain tube and other rotors with different structuralparameters, a series of experiments for different structures and different parameters of rotors were carried out in order to analyze its heat transferperformance and friction performance. And the PEC criteria which widelyused in project evaluation to evaluate the comprehensive performance ofrotors, was utilized to analyze the influence of structure parameters oncomprehensive performance of heat transfer enhancement and seek out onekind of rotor which is most suitable for industrial applications. From thestructure of rotors and the problem arising in the use process point of view,this paper has analysed the safety performance and service life of rotors. Inaddition, experimental analysis of rotors with different installation positionswas presented. And a new connection mode was presented in order to raisethe safety of rotors in service.Turbulence experimental investigation on visual experiment devicewhich was self-designed and constructed has been presented in order toqualitatively study the disturbance effect of rotors on tube-side flow. Finally,through rotate speed experiment draw the start rotating speed of rotors.