The Study And Development Of Integrated Control System For Chemical Water Workshop Of Power Plant

Chemical water workshop of power plant is a place to perform chemical water-treatment and provide eligible supply-water for boiler. It is very important for operating securely and economically of power plant that treatment equipments of supply water for boiler could function safely and supply water is of high quality. In China, the phenomenon is that automatization of desalting system is usually low and production condition is dropped behind. Presently, treatment equipments of supply water for boiler are mostly under artificial control, leading to over-standard amount of acid and alkali used and reduced economic benefit. Chemical instruments which are always sample line-absent have low accuracy that usually makes quality of water unable to control steadily which not only affect the common operation of boiler but also bring bad results if boiler had no water or stopped once supply water produced by desalting system was not enough. The pH value control for chemical neutralized pool of Chemical water workshop exists the problem of low automatization and bad control effect, which results in wasting a lot of neutralized agent of acid and alkali. Furthermore, the letting of pH over-standard water would affect the environment seriously.In this paper, control system nowadays for industrial process and developing status and trend for integrated automatization of flow industry in domestic and abroad are summarized, followed by principle of desalting system, flow of chemical water-treatment system and technics flow of various equipments are analyzed, which is based on investigating the automatization of single equipment and the whole flow of desalting system. Aiming at the solution to the problem of pH value control for neutralized pool, characteristics of neutralization process is expatiated, coming up with a new design of neutralized pool's structure and technics to decrease the time for sufficiently reaction of acid with alkali remarkably, based on which a pH value control system for neutralized pool is designed. In this work, the design methods of process control system for Chemical water workshop, including type-selection of I&C equipment, type-selection and configuration of PLC, methods and principles for program design of upper and nether computer is introduced in detail. Based on these principles and methods, the design of control system for Chemical water workshop which could run steadily in application received good evaluation from users. Moreover, the OPC technique is summarized and the interlinkage between PCS and SIS achieved by using OPC client/server technique is discussed.Finally, the work in this paper is concluded and the deserved and needed work to do for the future is also brought up.