Superheater

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Superheater Steam Temperature control and Intelligent Control Modeling: Report C.Sirichanchaikul
Abstract—The report deals with simulation of both dynamics and control of power plant superheaters by means of Vissim Program. The comparison between PID controller and PI cascade controller will be selected, demonstrated and analyzed with results, discussion, recommendation and conclusion. Superheaters are heat exchangers that transfer energy from flue gas to superheated steam. A composition of superheater, its input and output pipelines, and fittings is called a superheater assembly. It will utilize and adapt the knowledge that was gained from the assignment no.1 to simulate the superheater model and 2 controllers models (PI Cascade and PID controllers) for the better control of the super-heater as it is vital to the operation of a power plant, which has the characteristics of large inertia, large time-delay and time-varying. The Ziegler-Nichols tuning method will be applied to the proposed controllers in order to optimize the parameters of the controller. The comparison of the results of the two proposed controllers will be discussed. In this report, the simulation of the Superheater steam temperature control demonstrates that PI cascade controller are effective, practicable and better than typical PID control. INTRODUCTION

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his report has been prepared by the assignment no.1, classroom textbooks in order to apply these knowledge and technologies to generate models of superheater and controllers. It aims to improve the superheater steam control in fossil-fired power plant and to show a good understanding in power plant control. The superheated steam temperature is an significant objective of boiler motion quality and it has an largely effect on the fossil-fired power plant[1]. If the superheated stream temperature is higher than normal, a superheater is cracked simply and the apparatus in steamship are expand excessively. The equipment is less efficient and the vane of steamship is worn easily if the superheated stream temperature is lower.

This review relates to the new proposed modeling of the controller of the steam temperature. The majority of the power plants were built with typical PID controllers (Proportional, Integral and Derivative controller). The typical PID controllers have some issues of steam temperature control as the steam temperature control has complicated characteristics, e.g. nonlinear, uncertainty, time-varying, etc., In this report, a PI cascade control system and PID controller are proposed to improve the performance of regular superheated steam temperature control system under the superheater model which will be generated by Vissim program. The comparison between the PI Cascade and PID controllers will be conducted with results and analysis. Brief State of Intelligent Control system (State of the art literature review) This session will give details of the four different intelligent control modeling and how they are implemented in steam temperature control in coal-fired power plant. In addition, as for the improvement of steam control stability, new computational methods are developing to support the modeling.

Fuzzy (logic) control
As per the literature reviewed, the new superior technique mostly used is Fuzzy-immune PID which is explained below. Recently, Artificial Immune System (AIS)[1], which have already been demonstrated its robustness and flexibility against dynamically changing world, has been one of the technologies which draws attention on many automatic engineering [1]. As per the studies on immunology, the biological immune system does not only identify and remove the non-self materials, but it also have significant function to maintain its own system against dynamically changing environments [1]. As a result, the AIS would be anticipated to provide a new methodology suitable for dynamic problem due to the biological immune system imitation. Presently, scientific researcher...
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