| The device of cooling-drum is an important part of the production line of rubber-film,and its role is to cool the rubber-film sufficiently in order to avoid performance degradation in the case of high temperature for a long time.For example,the molecular chain of the rubber-film is easy to break in this situation.Therefore,cooling of the rolling rubber-film on cooling-drums plays a vital role for the quality of the rubber-film.In this thesis,by combining the theories of fluid mechanics and heat transfer,fluent software is used to simulate the stable heat transfer process of the rubber-film on the cooling-drums,and analyze the influence of various parameters on the cooling efficiency of the rubber-film.The main contents are as follows:(1)Based on the theories of fluid mechanics,heat transfer and numerical simulation,the comprehensive problems of flow and heat transfer during the process of cooling the rubber-film were studied,parameters affecting the the heat transfer were analysed and the relevant mathematical models were established.(2)In order to solve the problem of heat transfer simulation of a solid rubber-film moving on rotating drums,a method called rubber-film cooling simulation under heat-fluid-solid coupled heat transfer is proposed.By simulating the film with a so-called fluid film,a 3-D coupled fluid flow and heat transfer model for the rubber-film cooling simulation was established.(3)The cooling processes of six rubber-films on ten cooling-drums were simulated and temperature distributions at the rubber-films and the cooling-drums were obtained.Comparing with the experimental measurements found that the simulation results well agree with the experimental ones,indicating that the method proposed here is valid.(4)A finite element model for a single cooling-drum was established.Factors that affect cooling efficiency of the rubber-film were systematically analyzed which include technological parameters of rubber-film cooling process and structure parameters of cooling-drum.The former include thickness and width of the rubber-film,the speed of production line,the temperature of the rubber-film entering the drum,the temperature and flow of the cooling water entering the drum,the temperature of the environment,the angle of contact of the rubber-film;and the latter consists of the wall thickness and the material of the cooling-drum and the height of the spiral passage,etc.Influence trend of each parameter on the cooling efficiency of rubber-film is found.(5)Parameter sensitivity analysis method was employed to analyze effects of the main parameters on the rubber-film cooling efficiency.It is found that the temperature of the rubber-film entering the drum is most significant to affect the rubber-film cooling efficiency.Followed are the thickness of the film and the speed of the film.The ambient temperature is the last one to affect the cooling of the rubber-film.These results provide valuable references for the reasonable design of the cooling process of the rubber-film. |
PDF Full Text Request