PLC Based a Robust Solution for an Urban Area Water System Dilemma

The rapid growth of the wide urban residential areas imposes the expansion and modernization of the existing water supply facilities. In the mountainous city of Zintan, for example, the water system suffers from a lot of limitations including low reliability and maintainability due to the manual operation. This paper presents transferring the current water system to a complete robust automatic system to ensure a reliable and low-cost water supply system. A new piping and instrumentation diagram that involves feedback control system and sensors is developed. The control algorithm uses a smart level system for two tanks in which different water suppliers, including well pumps and feeding each tank to the other, are switched ON or OFF depending on the water level in each tank independently. The advantage of this strategy is to avoid dry run issue and to ensure continuous water supply to the urban area. To improve the bearing life of wells submersible pumps, they are divided into groups and each group feeds a certain tank for a limited period of time. The control algorithm is implemented using the Programmable Logical Controller (PLC). Simulation of the proposed system shows an elegant, flexible and easy configurable system designed on a low cost and accurate performance with almost zero human interaction.