Modelling and design of controller for reverse osmosis desalination process

Abstract

Due to the rapid growth of population and the water consumption per person in newlineday to day life, the demand for water supply is increasing considerably. According to newlineresearch from the World Health Organization (WHO) strategy, the fresh water resource is newlinearound 1% of the world. Water is the most essential for the survival of all living things. newlineFor example, an aquifer may become contaminated, if it is being recharged from a river newlinewhich has become polluted, or from infiltration areas, that contain a concentration of septic newlinetank wastewater disposal systems. With those multiple factors affecting the water quality newlineand consistency, careful planning must proceed, before the utilization of any water source. newlineDesalination, as a natural phenomenon has occurred on earth for millions of years. newlineReverse osmosis (RO) membrane desalination has emerged as one of the newlinestandardized techniques for desalination, due to its low cost and efficient energy process. newlineThe thesis is intended to design advanced optimized controllers for a RO desalination plant newlinesystem. The desalination plants are the higher order plants, which exhibits sluggish newlinebehaviour. This means that the plant has large settling time and peak overshoot, which are newlineundesirable for better performance. In order to improve the time domain characteristics, newlineseveral controllers were used and compared for RO desalination system and the newlineperformance of RO plant model is determined. Controlling industrial plants requires newlinesatisfaction of wide range of specification. So, wide ranges of techniques are needed. newlineMostly for industrial applications, integer order controllers are used for controlling newlinepurpose. Recently, fractional order controllers have been used for industrial applications, newlineto improve the system control performance. FOPID is the advanced version of conventional newlineProportional Integral Derivative (PID) controller. FOPID is better, as compared to newlineconventional PID controller, in which enhances the system performance and has the newlineproperty of iso-damping.