Study Of Control Of The Replenishment Water System Of Boiler In Power Station Automatically

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 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 economic benefit is reduced.The present paper takes Shandong Befar Group's automatic control system of the boiler makeup water as a background, elaborates the process of design of the water treatment control system, and studies the Reverse Osmosis water treatment emphatically.With Programmable Logical Controller, Siemens S7-400 being a hardware development platform, and with Siemens software STEP7 & WinCC6.0 being a software one, this paper detailedly describes the hardware choice, configuration, the development of the low computer PLC and the high computer monitor software. Moreover, the introduction of the low computer PLC double redundancy control system and the engineering application of PROFIBUS Field-Bus are done 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. The article introduces the technological characteristics of the Reverse Osmosis water treatment and requirements of the control system, and regards the water processing control equipment, Ultrafiltration and Reverse Osmosis , as the main research objects,Finally, a detailed summary to the scene debugging process has been made. The practice proves that this system has achieved the anticipated control request and the movement is good.