The Design Of Process Control System And Method Of Water Heater Of Power Plant

High pressure heater system as an important part of power generating units circulating water treatment.It is the role of high temperature and high pressure steam extraction from the turbine exhaust to heat the feedwater deaerator.The water will eventually be sent to the boiler drum.Stable operation of heater system to ensure the entire power plant economic benefits.If the operation of high pressure heater system is abnormal,boiler water supply system overheating economic benefits can be decreased,the amount of coal consumed by the unit generating capacity will also increase.When the high pressure heater system Water Leakage rupture accident,will cause great harm to the running of the unit.At present,the single loop control system is widely used in modern engineering field.In the operating process of high pressure heater system in power plant,using single loop control of high-pressure water level and according to the requirements of the high pressure heater system design to set water level control and alarm value.When the water level fluctuation of water level changes,and the input end of the feedback signal value setting were compared.The deviation signal is output to the actuator to adjust the water level,eliminate the deviation of the water level,and ensure the stability of the water level in the regulation range.In addition,based on the principle of heater heat exchange,the end of the high pressure heater is analyzed.It ensures that the system can meet the requirements of high rated power,ensure the efficiency of water heat exchanger.Modern industrial production systems are often complex multivariable systems.Due to the coupling effect among the variables,the complex production process becomes more difficult to monitor.The coupling effect of multi variables not only increases the control difficulty,but also causes the decrease of the quality of the control system.If the coupling effect is too serious can lead to the control system can not operate,and even cause the system paralysis and other major accidents.High pressure heater system of AISC second power plants have coupling effect.This makes the water level control due to instability and frequent accidents.Combined with the modeling principle of MIMO system,the mathematical modeling of high pressure heater coupled system,to solve for the transfer function matrix of coupling system of high pressure heater.The decoupling method of modern industrial system requirements are: the coupling system using diagonal matrix decoupling,integral decoupling,and feedforward compensator decoupling.By eliminating the coupling of the variable,the HPS coupled system is transformed into two independent single input single output system.Finally,the MATLAB system software were simulation design and analysis of high pressure heater water level,and combined with the experimental results to demonstrate the accuracy of the decoupling of high pressure heater water level control method.Now with the development of science and technology,DCS distributed control system in industrial production has been widely used.The characteristic of DCS control system based on TPS,we introduced the United States Honey Well Company R & D integration scheme.It adopts industrial controllable network safe and fast,fieldbus and industrial control systems are integrated together without trace.It will be the man machine control network in order to link,so as to solve the control demand of modern industry.