The first dry tower of the plant has been in operation since 2015. “When operational, the second tower will help cut 75% of the annual water consumption,” IRNA quoted Abdolmajid Dinarvand as saying.
The main purpose of large, industrial cooling towers is to remove the heat absorbed in the circulating cooling water systems in power plants, petroleum refineries, petrochemical plants and natural gas processing plants.
Dry cooling towers conduct heat transfer through air-cooled heat exchangers that separate the working fluid from the cooling air. Because there is no direct contact between the working fluid and the ambient air, there is no water loss in such systems.
Currently, the Hamedan utility uses treated wastewater for cooling, Dinarvand said, adding that using the treated sewage “has reduced groundwater abstraction to zero”.
Hamedan Wastewater Treatment Plant treats 650 liters of wastewater per second and the recycled water is piped to Shahid Mofateh Thermal Power Plant and farms.
Recycled wastewater accounts for nearly 85% of water used in the power station for cooling. Using treated sewage has prevented creation of sinkholes in the plains and curbed desertification.
Replacing groundwater with treated wastewater has resulted in the sealing of 25 wells around Hamedan City. As per an Energy Ministry directive, it is mandatory for all thermal power plants to use reclaimed wastewater [instead of potable water] for cooling needs.
Power plants are gradually replacing costly water from wells, lakes and rivers with reclaimed wastewater.
Environmentalists and experts are of the opinion that industries can and must use recycled water for heating and cooling instead of the scarce, costly and fast dwindling potable water.
Reports say 216 wastewater treatment plants are operating in Iran with an annual output of 1.2 billion cubic meters. Treated sewage is supplied for farming (57%) and the rest to industries, urban green spaces and to replenish surface and groundwater resources. Almost 70% of water consumed in households turns into sewage.
With a capacity of 1,000 megawatts, Shahid Mofateh Power Plant is located 47 km northeast of Hamedan. “The power station supplies the total demand of over 1.8 million people in the province and part of the needs of neighboring provinces,” Dinarvand said.
Although natural gas is the main feedstock of the thermal plant, it sometimes is forced to use mazut, normally in winters, when gas supply is reduced to industries due to high consumption of households.
The power plant has a 40% efficiency rate and built by Iranian engineers and with domestically-manufactured equipment and parts. Construction of the second 500 MW power plant is due to begin soon in the province’s Malayer County.