Research And Application Of Thermal Efficiency Of The Whole System Of Cement Kiln

With the continuous development of the cement industry,the pure low-temperature waste heat power generation system matched with the cement clinker burning system has been a normalization device.At the same time,the collaborative disposal of various large quantities of industrial solid wastes and hazardous wastes by the cement kiln has become the recent development trend of the cement industry.Based on the above,this paper expands the research object of thermal efficiency from the conventional burning system to the whole kiln system of cement production,and analyzes the energy consumption and thermal efficiency of the whole system accurately,so as to fully grasp the operation effect of the whole system of cement production and further improve the utilization of heat in the cement production process.Based on the industrial field data,this paper compares the thermal efficiency of common firing system and supporting heat recovery device,determines the most reasonable process route,and carries out practical application in 4500 t / D production line,and draws the following conclusions:1)Benefit from the contribution of high solid gas preheating and decomposition system in improving gas-solid heat exchange efficiency and carbonate decomposition rate,when the combustion system adopts high solid gas ratio suspension preheating and decomposition system,the thermal efficiency of the combustion system can reach60.62%,which is higher than the conventional combustion process;2)The comparison of two common mature heat recovery processes,slag grinding and waste heat power generation,shows that the heat recovery efficiency of slag drying by using the heat in flue gas is higher,which can reach 53.40%,far higher than the heat efficiency of waste heat power generation of 12.53%;3)When the high solid gas preheating decomposition system is used in the firing system and the slag grinding process is matched,the heat in the waste gas from the firing system can be recovered,which can effectively improve the thermal efficiency of the whole system;according to the process route,the Fuping 4500t/d production line is built,with the clinker output of 281.54t/h,equivalent to 6767t/d;the clinker firing heat consumption is 2773.84 k J/kg.cl,and the sum of the effective heat in the whole system reaches 1931.19 k J/kg CL,the thermal efficiency of the whole system is 69.62%,which is basically consistent with the design index of 69.30%;4)The thermal efficiency of Fuping eco cement production line and CZ production line with high solid gas ratio suspension preheating decomposition technology is significantly higher than that of the conventional YD production line,and the thermal efficiency of Fuping production line with slag grinding is higher than that of CZ production line with waste heat power generation.Theoretical research and industrial application show that the whole system thermal efficiency can be effectively improved by adopting high solid gas preheating decomposition system and slag grinding process.