Energy Efficiency Analysis And Process Parameter Optimization Of LPCVD For Nano-TiO₂ Film

Since the 21st century, the rapid development of nanotechnology has made it one of the world's leading scientific and technological frontier areas. With the deepening research of nano-materials, the application of nano-materials has been extended to various domains. Because of the distinctive photocatalysis properties, the nano-TiO2 film is widely used in pollution control and self-clean glass. However, it confronts with issues like high energy consumption and low efficiency during the preparation of nano film, which is conflict with the current situation of scarcity of natural resources and energy conservation in recent years. Therefore, the investigation on energy consumption mechanism and energy efficiency promotion of nano film preparation has become increasingly urgent.The research objective in the present study is low pressure chemical vapor deposition process for nano-TiO2 films preparation. According to the relevant knowledge like chemical fluid mechanics, law of conservation of mass and principles of nano films preparation, kinematic equation of gaseous mixture in reacting furnace and concentration function of precusor in upside substrate are determined, which provides the basis for the establishment of nano-TiO2 film deposition process function model. In addition, based on relevant thermodynamics theories, we obtained the thermodynamic value of precusor and related chemical reaction under specific technological conditions and further built the parametric thermodynamic model of the chemical reaction. In light of thermodynamic values of unit time in chemical reaction determined by the deposition rate of nano-TiO2 film, valid energy model with regard to the deposition process are established. Furthermore, this model will be solved by referring to relevant manuals and literature in which parameter values under different technical conditions can be obtained. The solution of the model help to gain the utilization rate of precusor, mass of nano film deposited in certain time, valid energy and specific energy consumption in preparation process under different technical condition. The next part of this paper, we analyzed the calculation results under different condition based on the orthogonal test design method. Firstly, primary and secondary analysis of influential extent exerted by three factors on experimental indicators is conducted by poor value of each factor. Secondly, variance analysis method is adopted to calculate the test statistics under different factors and levels for the purpose of optimizing a single test index; and the significance of various factors are also examined. Finally, according to the orthogonal matrix method and multiple optimization objectives, the weight values about different levels were calculated to get the optimal process parameters. In the end, based on FLUENT, enthalpy of each material in the preparation process is simulated. The theoretical calculation data are compared and analyzed with the simulation data to demonstrate the validity of the energy utilization model.