Development of fuzzy controller for water level in stream boiler tank

Abstract

Problem statement: The process control of steam boiler is very popular used in the industrial. The temperature of the water is transferred directly by electrical heater. The pressure will increase based on the changing of the temperature. The purpose of the control is to change the opening set point for the valve when the temperature and pressure in the tank are changed. For this problem, we develop fuzzy algorithm to adjust the optimal percentage of valve open. Approach: In this study, the fuzzy control application was programmed in fuzzy control language in form of the function block using structure control language. The input information consisted of real variables in the form of measurable process variables, as well as set points. And the output variables were real variables in the form of correcting variables. Results: The fuzzy control was developed, which consists of two input variables, the degree of temperature and pressure in boiler tank measured by sensor. For fuzzy system of water level control, the algorithm is basically implemented in form of the MATLAB code. In the experiment, we assumed that the water level would not effect to the temperature and pressure. Conclusion: The research for the development of the fuzzy logic and the model was tested with the step inputs and the changing of the inputs. The whole simulation process was built to test the behavior of the system when the inputs change. © 2010 Science Publications.