Design and Simulation of a Monitoring and Controlling System for the Cooling Tower of Khartoum North Power Station

Abstract

Khartoum north power station is a thermal power station that has three phases. Each phase consists of two units with their components, namely, a boiler with auxiliaries, a turbine with auxiliaries, and a generator with auxiliaries. The cooling tower is one of turbine auxiliaries. It is a heat rejection device used to transfer process waste heat to the atmosphere. Make-up water for the cooling tower`s reservoir must be supplied under level control. In case of a malfunction of the ball float system the supplied water to condenser will not be regular which may cause a vacuum problem resulting in load instability or even causes the unit to trip. In this research, the ball float system was suggested to be replaced by a level sensor which provides a level signal to a PLC. The PLC controls the motor that operate the supply valve of the cooling tower via the PID control module of the PLC. The optimum control parameters of the PID control module were obtained by trial and error runs of the Simulink module of the MatLab package. The suggested control system was simulated and was found to perform nicely.