Numerical and experimental investigation of the effect of the optimal usage of pump as turbine instead of pressure-reducing valves on leakage reduction by genetic algorithm

The leakage, caused by design problems, pipe breakage, and fittings' failure, is a critical challenge that the beneficiaries face in the water distribution networks (WDNs). Control and management of the network pressure have always been considered helpful solutions to reduce the leakage in these systems. In the present study, locating and setting of the five pressure reducer valves (PRVs) have been optimized using GA (genetic algorithm) to minimize the leakage and make uniform pressure. Results show that the network leakage has reduced 21% from 34.53 lit/s to 27.26 lit/s. In the next step, the PRVs are replaced by two pumps as turbines (PATs) at two desirable points for converting extra elevation head of the real gravity WDN to generate electricity. It is also found that the performance of PATs in reducing the amount of leakage is similar to PRV, and there are slight differences. Therefore, nearly 153 MW/year is generated using two PATs that resulted in 15,000 $/year in cost-saving. As estimated, the cost for installing and operating two PATs is $14,000, so the return on capital will be at least one year.