Water conservation in power plant wet cooling tower through changing into hybrid tower using two airflow control systems

Wet cooling towers have a high cooling capacity. However, owing to consumption of large water quantities in wet cooling towers, using them in arid regions facing water resource crisis might cause operational problems. In this research, changing the wet cooling tower of unit 5 of Isfahan Islamabad power plant into a hybrid cooling tower, using parallel path wet/dry configuration is studied. The hybrid cooling tower with the recommended configuration causes minimal changes in the other power plant facilities and has a low construction cost. Two different airflow control systems are investigated for the wet and hybrid cooling towers. In the first system, the amount of airflow rate in the cooling tower is adjusted by means of switching tower ID fans on or off. In the second system, an optimum airflow control mechanism with high-tech fans is devised. The results reveal that the optimum airflow control system is more suitable than the other system, due to less water consumption, preventing the sudden fluctuations of airflow and consequently water consumption rates and less fan power consumption. Experimental data and results obtained by the HTFS software are used for validating the simulated results of the wet cooling tower and air-cooled heat exchangers, respectively. The results demonstrate that the annual amount of water conservation due to changing the wet cooling tower into hybrid tower is approximately 343830 and 348718 cubic meters for fan switching and optimum airflow control systems, respectively.