The Engineering Research And Implementation Of Flue Gas Desulfurization And Dust Removal From Thermal Power Plant Boiler

In response to the national call for energy conservation, emission reduction and environmental protection, Baling Petrochemical Company considered the actual situation, that there are both ammonia source and ammonium sulfate outlet inside the company, adopted the technology of flue gas desulfurization by ammonia absorption with streamer discharge enhancement, and modifed the flue gas desulfurization and dust removal system of No.1boiler at first-phase project of Power Supply Division, to reach the pollution emission standard. It is a new desulfurization process, which was developed by combining ammonia absorption with plasma technology. It is an innovation and development of conventional ammonia absorption technology. It has become one of the key scientific direction supported by the country in the field of flue gas purification technology. The technology has the advanced technological process, the reliable material selection, the optimization of traditional sulfite oxidation system with plasma technology and the adoption of electric demist technology with super mist removal ability at the end stage. It can completely resolve the difficult problems of the conventional ammonia absorption technology, including equipment corrosion, clogging, ammonia escape, acid mist, aerosol above the standard and etc.In this paper, the author studied plasma generation technique by streamer discharge, analyzed the process of flue gas desulfurization by ammonia absorption with streamer discharge enhancement, and verified the higher desulfurization efficiency and advancement of this technology by comparing with the conventional ammonia absorption method. Then, the parameters of the boiler were designed. And the author researched the application of this technology to the exhaust flue gas of boiler in the power plant. Finally, the author investigated the trial operation situation of this technology for168hours in No.1boiler of Power Supply Division, Baling petrochemical company, and analyzed the operation data theoretically. The main research work of this dissertation is as follows:Firstly, the domestic and foreign status of flue gas desulfurization technology was summarized, and the basic principles of flue gas desulfurization technology with ammonia absorption with streamer discharge enhancement was studied. Through the analysis of desulfurization mechanism, the flue gas desulfurization process by ammonia absorption with streamer discharge enhancementwas designed, the advantages of this technology were compared with the conventional ammonia desulfurization technology. This technology not only can control the escape of ammonia below5mg/Nm~3, get ammonia-sulfur ratio to2.03at desulfurization, increase the denitrification capacity, reducing the overall energy consumption; and but also can remove the droplet which is more than2μm, achieve control targets of15～ 75mg/m3at the end stage, reduce the corrosion of the flue and chimney. It minimizes maintenance costs, and ultimately achieves the ideal goal of "energy saving and emission reduction".Secondly, in view of low efficiency, high cost of conventional ammonia desulfurization, high content of contaminants in flue gas from thermal power plant, and so on, the technology of flue gas desulfurization by ammonia absorption with streamer discharge enhancement was applied to flue gas of boiler in thermal power plant. The desulfurization efficiency was improved, and the ideal purpose of no secondary pollution was achieved by selecting a reasonable desulfurization method, designing the high effective engineering technology program, using the advanced control methods,.Thirdly, in order to verify the effectiveness of desulfurization technology under research, according to the specific conditions of Baling Petrochemical Company, combining with the survey and comparison of current status of desulfurization technology in the petrochemical system, the ammonia desulfurization technology was applied to flue gas desulfurization project of No.l Boiler in Power Division of Baling Petrochemical Company. The project successfully started-up on March2,2011, and passed the168hours acceptance inspection on March20. Through assessment of stable operation and detection of multiple departments for many times in half a year, all indicators reached or were higher than the contract requirements and relevant national standards. The desulfurization efficiency was higher than99%(design value is95%), the oxidation rate of sulfite was higher than99.5%(design value is98%), ammonia escape of tail gas was2.24mg/Nm~3(national standard is8mg/Nm3), fog concentration of tail gas was26mg/Nm~3(emission standard is75mg/Nm~3).The theory analysis and the achievement of the project of Baling Petrochemical Company showed that the project adjusted measures to local conditions, realized the goal of environmental control and made full use of the economic value of by-product ammonium sulphate and fly ash simultaneously. The project also had a considerable water saving and emissions reduction ability and the economic benefit was obvious.