The construction of the dry cooling tower of the second unit of Shahid Mofatteh Thermal Power Plant in Hamedan Province has registered 60% progress, the head of Thermal Power Plants Holding Company said.
The power stations consumes about 12 million cubic meters of treated wastewater a year.
“Upon completion, it will help reduce water consumption by 85% in the unit and contribute to the stability of the production capacity of the 250-megawatt unit,” Barq News also quoted Abdolrasoul Pishahang as saying.
The water saved in the process will be supplied for agricultural and industrial operations.
“Previously, the project to change the cooling system of a power plant in Iran was carried out for the first time at the first unit of the power plant and it has saved 85% of water consumed in the unit,” he added.
Dry cooling systems use air instead of water to cool the steam exiting a turbine. Such systems do not use water and can reduce total power plant water consumption by over 80%.
The main purpose of large, industrial cooling towers is to remove the heat absorbed in the circulating cooling water systems of power plants, petroleum refineries, petrochemical plants and gas processing plants.
While wet cooling towers are designed to evaporate water into the air that flows through the tower, dry cooling tower systems work differently in that they transfer heat from the power plant directly into the air.
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.
With a capacity of 1,000 megawatts, Shahid Mofatteh Power Plant is located 47 km northeast of the capital city of Hamedan.
The power station meets the total demand of over 1.8 million people in the province and also part of the needs of neighboring provinces.
Main Feedstock
Although natural gas is the main feedstock of the thermal plant, at times it is forced to use mazut, normally in winters, when gas supply is reduced for industries due to the high consumption of households.
Built by Iranian engineers and with domestically-manufactured equipment and parts, the power station has a 40% efficiency rate.
“The treated wastewater in Hamedan has been used for cooling operations in this power plant since 2015,” Pishahang said.
“The measure has helped seal 25 wells, from which water was extracted for cooling purposes in the plant, to help preserve the precious groundwater resources.”
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.
Hamedan Wastewater Treatment Plant treats 650 liters of wastewater per second and the recycled water is piped to the power plant, farms and industries.
Recycled wastewater accounts for nearly 85% of water used in the power station for cooling. Using treated sewage has prevented the formation of sinkholes in the plains and curbed desertification.
Power plants are gradually replacing costly water from wells, lakes and rivers with reclaimed wastewater.
Environmentalists and experts believe industries can and must use recycled water for heating and cooling instead of the scarce, costly and fast dwindling potable water.
