Research On Heat And Mass Transfer Of Flue Gas Desulfurization System Of Coal Fired Boiler

Wet desulfurization is a relatively mature desulfurization technology with high desulfurization efficiency.However,due to its high cost nature,some enterprises are discouraged.Therefore,how to reduce the operating cost on the basis of the desulfurization efficiency is particularly important.In this paper,a coal-fired boiler flue gas desulfurization system which can use waste heat is proposed,and the waste heat is used on the basis of ensuring the desulfurization efficiency.This paper will mainly from the establishment of the heat and mass transfer model of the spray desulfurization tower,the study of the characteristics of heat and mass transfer process of the spray desulfurization tower,the study of the unsteady working characteristics of the spray desulfurization tower and the design and working characteristics of the flue gas desulfurization-waste heat recovery system.By understanding the basic principle of wet desulfurization,calculating the physical parameters of the flue gas to be treated and controlling the relevant dimensions of the desulfurization tower,the preconditions for high efficiency desulfurization are set.On this basis,according to the energy conservation,mass conservation and some change processes,the liquid and gas analysis and the mathematical model of heat and mass transfer in the desulfurization tower are established,and the function relationship of the relevant variables is obtained.Using the numerical method to solve the mathematical model,the relationship between flue gas temperature,flue gas moisture content,slurry temperature,desulfurization efficiency and heat exchange rate is obtained.The characteristics of some key parameters in the system are analyzed,including reaction zone height,flue gas inlet temperature,slurry inlet temperature and gas-liquid ratio.the theoretical results show that desulfurization efficiency increases with the increase of desulfurization slurry temperature and the decrease of droplet size.The establishment of heat and mass transfer model in the joint spray tower and the analysis of heat and mass transfer characteristics,the mathematical model of desulfurization system including desulfurization tower and open slurry tank is built using energy conservation.By solving the mathematical model by differential equation,the function relation of the slurry temperature is obtained.the slurry equilibrium temperature of the desulfurization system is negatively correlated with the flue gas inlet temperature,outdoor wind speed,the area of the open slurry pool and the relationship with the ambient temperature.Finally,based on the Harbin heating group Hua Hui hot spot energy-saving reconstruction project case analysis.Taking the numerical value of the final equilibrium temperature of the desulfurization slurry as the object,a waste heat recovery device is added to the existing desulfurization system,and the operation characteristics are studied.Based on this project,the influence factors and the economic analysis of the system are discussed,and the flue gas desulfurization-waste heat recovery system is a profitable,energy saving and suitable investment project.This paper focuses on the combination of desulfurization efficiency and heat recovery,discusses the way to ensure a certain desulfurization efficiency,studies the maximum amount of waste heat recovery and influencing factors analysis,for the actual operation of the enterprise to provide theory and data reference.