| Temperature and pressure reduction system is an essential part of the boiler equipment, whether for utility boilers or industrial boilers, reducing the role of temperature and pressure systems are the high-pressure superheated steam (first steam) section through the Reduction Valve flow throttling valve sleeve and hole reduce the vapor pressure effect, through the water valve to a water spray to reduce the steam temperature of steam, but after the system temperature and pressure reduction of steam treated (secondary steam) the temperature is too high will make the turbine inside the device followed by thermal expansion over the serious impact on safe operation; low temperature will not only reduce the efficiency of operation of equipment, but also the steam turbine and humidity after a few levels increase, causing blade wear. How to design reasonable control algorithm to maintain the temperature of the secondary steam in the permitted range, is an important research paper.The subject of a steam flow of 10 tons per hour parameters of the specific requirements of condition, design calculations Reduction Valve and the water valve of the important parameters, such as the flow coefficient, throttle series, cutting down the sleeve noise volume, a flow rate of steam in the pipes, condensation of water flow.Reduction Valve throttle sleeve is an important component, not only from the role of throttle, but also the principle can be used to reduce the orifice amount of noise inside the body. In this paper, finite element method, using ANSYS finite element software design Reduction Valve throttle sleeve modal finite element analysis to calculate the throttle sleeve designed by the 10 natural frequencies and mode shapes.Temperature control system for nonlinear, time delay, time-varying characteristics, the traditional PID control strategy is difficult to obtain satisfactory control quality, causing to the actual project inconvenience. The robustness of fuzzy control is good, but the time delay and change of control object parameters are not sensitive to steady-state control rule rough prone to error. In this paper, the classical PID control algorithm and fuzzy control algorithm, analysis and comparison of the conventional method of PID parameter tuning, a fuzzy self-tuning PID control algorithm while maintaining PID control the steady-state error is small, good stability advantages, but also has fuzzy adaptive speed control and adjustment features.In this paper, the second steam temperature is controlled object, the establishment of a secondary steam temperature control system simulation model to test system performance, through the use of MATLAB software, respectively, the conventional PID control and fuzzy PID control are simulated . The results show that the fuzzy PID control is effective to improve the system of nonlinear, time variability and uncertainty of the processing power and control better. Its comparison with conventional PID simulation, reflecting the fuzzy self-tuning PID controller, and advantages of the nature of its control system to improve the accuracy of great reference value. |
