Theoretical Research And Application Of The Life Cycle To The Evaluation Of The Ceramic Products' Comprehensive Benefit

Building material industry is an important basic material industry and raw material industry. In recent years, the rapid development of the economy, as well as large-scale infrastructural construction are promoting the development of the traditional building materials. But it also brings the resources consumption, energy shortages and pollution problems. Ceramics are important building materials. Recently ceramic manufacturing industry is developed very quickly in our country. Although the production and export of ceramics have been ranked first in the world since 1993, but heat consumption, power consumption, pollutants emissions etc. are concerned, there is still a large gap compared with the advanced international level. Thermal process is the key for saving energy, reducing consumption and decreasing the pollutants emission, and also an important guarantee of high quality product. Therefore the research on thermal process technology not only may promote the development of ceramic manufacturing technology, enhance international competitiveness of our ceramic industry and ceramic products, and also have important practical significance for saving energy, reducing consumption, clean production in ceramic industry.Based on the situation of the ceramic industry all over the world, the theory and application to the evaluation of the ceramic products'comprehensive benefit have been studied in this doctoral dissertation. The main contents are as following:(1) The firing process of ceramic manufacturing is studied, and the fluid flow, heat transfer, mass transfer, physico-chemical changes in the kiln, as well as the interaction mechanism between them are analyzed. According to the actual operating conditions, combined with the modeling of firing process, the equations of gas flow and heat transfer in the kiln are derived, the generalized mathematical model of firing process are established, and the control and discretion methods used for the calculation of the gas flow and heat transfer in the kiln are determined. On the above analyses, by means of CFD, the modeling and simulation platform for firing process in ceramic kiln are proposed.(2) The thermal characteristics in ceramic firing process are studied, and the limitation of modeling based on mechanism is analyzed. Considering the characteristics of the strong nonlinear, strong coupling, uncertainty and big lag in kiln thermal process, based on the dynamic optimization theory, the model is established to predict the temperatures in the kiln. Through improved learning algorithm, higher forecast accuracy is achieved, and the adaptability of forecasting model.is realized.(3) The life cycle theory of building ceramics is discussed. As three fundamental, elements and characteristics, ecology friendship, aesthetics and economy are proposed and expounded. The specificity of LCA (life cycle assessment) for building ceramics is studied, according to the technical framework of LCA in ISO14040 series standard, the life cycle environmental performance of building ceramics in our country is assessed.The constitution of LCC (life cycle cost) related to building ceramic life cycle is analyzed. It is proposed that building ceramic life cycle cost is composed of life cycle financial cost and life cycle environmental cost. The methods and formulas to calculate these costs are also established. According to the general building ceramic life cycle, the analysis process of building ceramic life cycle cost is presented(4) The integrated framework of LCA and LCC is studied, and based on timing matrix, the algorithm for the inventory analysis is proposed. The integrated evaluation index system of LCA and LCC is established and applied to the evaluation of the ceramic products'comprehensive benefit. The index weights of this system are discussed. Based on FAHP (Fuzzy Analytic Hierarchy Process) and Entropy, combining the subjective weighting method and objective weighting method, the setting method of index weights in this system is proposed from three aspects (economic cost, energy consumption and emission of environmental). The calculation of the weights is demonstrated in detail; the objects (minimizing life cycle financial cost, minimizing life cycle environmental emission, artistic performance optimum and minimizing life cycle energy consumption) are put forward.Based on the life cycle of the building ceramic products'comprehensive benefit, the multi-objective optimization method is established finally.