Research On Multi-objective Optimization Of Ceramic Roller Kiln Firing Zone Parameters Based On Numerical Simulation

With the rapid development of China’s ceramic industry,people’s demand for ceramic tiles is increasing and the quality of the products is becoming higher and higher.At present,due to the backwardness of China’s kiln technology,the problem of "high energy consumption and poor quality" occurs during the production of ceramic tiles.Roller kiln is the thermal equipment that consumes the most energy in the ceramic tile production process,and its energy consumption is mainly concentrated in the firing stage.Therefore,in order to effectively promote the sustainable development of China’s ceramic manufacturing industry,and realize the production goal of "high yield,high quality,and low consumption",how to fully realize energy saving optimization in the firing belt from the viewpoint of energy consumption and firing quality is extremely important and urgent for China’s ceramic enterprises.For the issues of high comprehensive energy consumption and poor product quality in the production process of ceramic roller kilns,this thesis takes the firing belt of roller kiln as the object of study,and conducts multi-objective optimization research on its performance based on numerical simulation technology and intelligent optimization algorithm.Firstly,by analyzing the working principle and heat transfer characteristics of the roller kiln,the energy consumption evaluation model of the firing zone is constructed;secondly,the CFD model of the firing zone is constructed based on numerical simulation technology,and the model is validated by combining the enterprise research data,and the optimization parameters are determined by combining the analysis of simulation results,and the evaluation indexes for evaluating the firing quality of tiles such as the temperature dispersion coefficient and the relative overheating temperature difference are established.The optimized parameters are quantitatively analyzed by the single factor influence law;then,Taguchi experiments is designed combined with simulation Simulate to collected data,and the prediction model between the parameters to be optimized and energy consumption and quality are constructed based on the extreme gradient boosting method,and the multi-objective multi-optimization model are solved based on Non-dominated Sorting differential evolutionary algorithm to obtain the best parameter combination,and the optimization results are compared and verified;finally,The optimization system of energy consumption and quality of the firing belt is built based on Matlab,and it is realized.The main content of this article is as follows:(1)To address the problem that energy consumption is high and difficult to be evaluated during the production of roller kiln,this thesis proposes an energy consumption modeling method based on heat balance analysis.Firstly,this thesis studies the process characteristics of the roller kiln and the heat transfer characteristics of the firing zone.Secondly,the energy consumption evaluation model of the firing zone is constructed by analyzing the heat input and output relationship of the firing zone in combination with the method of heat balance analysis,taking into account the influence of heat brought in by flue gas,and the relevant parameters affecting the energy consumption are analyzed and derived.Finally,the reliability of the model was verified,and the maximum value of the relative error of the model is within10%,which shows that it can provide a theoretical basis for the later optimization research.(2)Aiming at the problems of long cycle time,high cost and limited data sample size of traditional experiments,this thesis investigates the flow field information inside the firing belt based on numerical simulation technology,proposes two evaluation indexes for the temperature field,and conducts quantitative single-factor analysis of the optimization parameters.Firstly,this thesis combines the operating principle of the roller kiln with the structural dimension to build a geometric model of the firing zone,simulates the basic working conditions of the firing belt based on Fluent software,and compare the calculation results with the thermal data of the company to prove the effectiveness of the CFD model.Secondly,the process and structural parameters are analyzed with the operation results,and the burner inclination angle,air-fuel ratio,and flue gas inlet velocity are determined as the optimized parameters in this thesis.Finally,the evaluation indexes of temperature dispersion coefficient and relative overheating temperature difference are constructed,and combined with the evaluation indexes,the single factor influence law of optimized parameters on the stability of temperature field is discussed.(3)In response to the time-consuming and computationally intensive problems of traditional optimization methods,this thesis proposes a multi-objective optimization strategy for "energy consumption-quality" of the firing zone based on a non-dominated sorting differential evolutionary algorithm.Firstly,this thesis combines Taguchi’s experimental design and numerical simulation to collect data under different working conditions.Secondly,using the optimized parameters as the input and the evaluation indicators as the output,constructing a prediction model of energy consumption and quality based on the extreme gradient boosting method.Finally,determining the interval of the optimization parameters,and the optimization model is solved based on the multi-objective differential evolutionary algorithm with the prediction model as the optimization function to obtain the optimal Pareto solution set,and the optimization results are compared with the initial scheme to verify the superiority of the optimization scheme.(4)In order to achieve scientific management of the above-mentioned optimization of the firing zone,combined with the above-mentioned research work,an integrated,informative and visualized multi-objective optimization system for energy consumption and quality based on the Matlab platform is built in this thesis.Firstly,the requirements analysis of the optimization system of energy consumption and quality of firing zone is carried out in combination with the above research work.Secondly,the general framework and functional modules of the system are designed,and the operation process of the system is studied.Finally,the optimization system is realized and applied in combination with Matlab software,which provides guidance significance for the actual production of the enterprise.