| The high-salinity organic waste liquid incineration boiler is an important equipment in the process of harmless treatment of organic waste liquid.Its fuel is mainly various organic waste liquid discharged during the production and operation of chemical enterprises.The organic waste liquid is harmless treated by combustion and the alkali salt is recovered.Compared with the traditional coal-fired boiler or alkali recovery boiler,the traditional boiler structure and operation mode have been difficult to meet the requirements due to the differences in fuel and operating conditions.It is very necessary to develop a new type of incineration boiler structure to meet the requirements of the combustion characteristics of high-salinity organic waste liquid.The incineration process of high-salinity organic waste liquid can be divided into three stages: drying,pyrolysis and internal inorganic salt reaction.Because the combustion characteristics of high-salinity organic waste liquid are quite different from the coal combustion model in fluent,it is necessary to put forward the corresponding mathematical model for the combustion of high-salinity organic waste liquid to improve the accuracy of simulation calculation.In this paper,the combustion mathematical model is determined by the combustion mechanism of high-salinity organic waste liquid and the content of internal components of particles.Due to the complex reaction model of high-salinity organic waste liquid,the combustion mathematical model is simplified by the combination of DRG method,sensitivity analysis method and genetic algorithm,and verified by the combustion mathematical model based on the ignition delay period and laminar flame velocity parameters.On the basis of the above work,fluent embedded program is written in the form of UDF,and the UDF program and combustion mathematical model are tested by two-dimensional model.The results show that the program runs stably,the simplified model can meet the calculation requirements,reduce the calculation cost,and qualitatively simulate the combustion state of high-salinity organic waste liquid.Then,based on the data of a high-salinity organic waste liquid incineration boiler in actual operation,this paper puts forward a reasonable simplified scheme and establishes a three-dimensional simplified combustion mathematical model by analyzing the internal combustion characteristics of the boiler.According to the actual working state,air distribution scheme and combustion characteristics of the boiler,the boundary conditions and reasonable mesh generation are completed.Using UDF program and simplified combustion mathematical model,the temperature,velocity,component concentration and particle trajectory distribution in the furnace were obtained.By comparing the calculation results with the actual operating parameters of the boiler,the results show that the calculation model and the simplified method of combustion model proposed in this paper can effectively predict the internal combustion and flow conditions of the high-salinity organic waste liquid incineration boiler.Using numerical simulation technology,the working state of waste liquid incineration boiler can be predicted in advance,so as to guide and optimize the boiler design and reduce unnecessary test costs.Through the analysis of the simulation results,the results show that the combustion organization of this type of incinerator is reasonable in general,and there are only some uneven heat exchange and ash deposition and slagging in local areas.In view of the problems found,this paper puts forward some structural optimization schemes such as the design of furnace angle flow line,and simulates some schemes,which provides a certain reference for the further optimization of boiler combustion performance in the future. |
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