Optimal Design And Evaluation Of Implementation Scheme For Water Recovery System In Coal Fired Power Plant

With the country’s strengthening of various water pollution treatments,water environmental issues in the power industry have gradually received widespread attention.The high-humidity flue gas at the exit of the wet desulfurization system of coal-fired power plants not only contains a large amount of moisture and waste heat,but also carries aerosol,SO3 and other components.The moisture recovery system of the power plant is an effective measure to control the emission of high-humidity flue gas.While realizing water-saving benefits,the waste heat energy in the low-temperature flue gas is used efficiently,and it is expected to synergistically reduce the ultrafine particles in the flue gas,slow down the atmospheric pollution problems such as equipment corrosion,gypsum rain and colored plumes.This paper aims at the optimization design and evaluation of the implementation scheme of the moisture recovery system of coal-fired power plants,and compares and analyzes the existing flue gas moisture and waste heat recovery technology,desulfurization wastewater treatment technology,and the integrated water recycling system integration process.The thermodynamic algorithm is used to theoretically calculate the energy saving effect of flue gas waste heat utilization,and the key technology and operating parameters of the moisture recovery system of the case power plant are used to analyze the influence relationship between the actual flue gas water heat recovery utilization effect and the technical equipment and steam-water integrated system process layout.Based on the results of the existing pilot experiments,the calculation and analysis of the relationship between the heat transfer effect of the membrane process system and the actual working conditions such as the flue gas temperature and cooling water flow rate and the heat transfer performance of the membrane module were carried out.Gas volume and flue gas temperature,reasonable reduction of cooling water temperature and cooling water flow rate,and modification of the membrane itself can help improve the moisture recovery efficiency of the flue gas.The membrane method system is more stable,and the quality of the recovered water is higher.The application prospect provides a basis for the optimization design and evaluation of the implementation scheme of the membrane-based flue gas hydrothermal system.Based on field experimental investigation data and simulation calculations,the evaluation and analysis of the recycled water volume and the factors affecting the quality of recycled water quality using different moisture recovery systems,and the corresponding analysis of the purification,treatment and utilization of recycled water,provide a reference for the assessment of the synergistic effect of in-depth emission reduction for the pollution of flue gas in the water recycling system of power plants.Based on the analysis of the advantages and disadvantages of the thermal and membrane technology for desulfurization wastewater treatment,and the analysis and discussion of the concept of thermal membrane coupling technology,it is planned to optimize the design of a set of low-temperature flue gas concentration coupled flash evaporation desulfurization wastewater zero discharge process + membrane module The layout of the flue gas moisture recovery system uses the fuzzy analytic hierarchy model(FAHP)to analyze and evaluate the original process plan,improved process plan,and optimized design process plan,and comprehensively considers economic,environmental,technical,and system adaptability factors.The innovative process of membrane-based flue gas moisture recovery and thermal membrane coupled wastewater treatment is superior to existing processes,and the optimal process plan is recommended for the case power plant.