The steam unit of Heris Combined-Cycle Power Plant in Heris County, East Azarbaijan Province, was connected to the grid on Tuesday, the project director of private power stations at the Thermal Power Plants Holding Company said.
“With a capacity of 180 megawatts, the steam unit has helped the plant’s total capacity reach 490 MW,” Rouhollah Espanani was also quoted as saying by the Energy Ministry’s news portal Paven.
“This is the second steam unit in the country’s combined cycle power plant, the gas unit of which has used F-class gas turbines that have high efficiency,” he added.
The official noted that the power station’s efficiency is above 56%.
“The power plant is one of the most efficient of its kind in the country. The addition of the steam unit helps save 250 million cubic meters of gas worth $50 million annually,” he said.
“The power plant has been built in the northwestern region of the country with the participation of the private sector and has used a new generation of gas turbines. With the launch of its steam section, the stability of the electricity network will increase significantly in the region.”
According to Espanani, $285 million have been spent on the construction of the power station, stressing that the design and construction of the plant were undertaken by domestic engineers.
Heris Combined-Cycle Power Plant gas unit, which came online earlier this year, consists F-class gas turbines and has a generation capacity of 310 MW.
F-Class Gas Turbines
The indigenized F-class gas turbines were first used in the gas unit of Hengam Power Plant in Bandar Abbas, Hormozgan Province.
F-class gas turbines are marked by high performance, low power generation costs, long intervals between inspections and a service-friendly design. Optimized flow and cooling add up to high efficiency and economically viable power generation in combined cycle applications.
The construction of F-class gas turbines in combined-cycle power plants is on the agenda of the Thermal Power Plants Holding Company to improve efficiency and reduce electricity waste.
TPPHC has signed a contract with the energy and infrastructure conglomerate MAPNA for the construction of 5,000 MW of thermal power plants by 2024 using domestically-made F-class gas turbines.
Such turbines consume less gas and are more eco-friendly and increase electricity generation in a simple-cycle and combined-cycle power plant by 40% and 59% respectively.
Effective steps have been taken to convert conventional plants into combined-cycle ones to improve efficiency and reduce pollution and costs.
A combined cycle power plant uses both gas and steam turbines to produce more electricity from the same fuel than a traditional simple cycle plant. The waste heat from the gas turbine is sent to a nearby steam turbine, which also generates electricity.
Average efficiency of domestic power plants is said to be around 37%. Thermal power stations account for 80% of total power generation of around 86 gigawatts in Iran and hence enhancement of their efficiency is crucial.
Energy efficiency of a conventional thermal power station, considered salable energy produced as a percent of the heating value of the fuel consumed, is typically 33% to 48%. Considering all the heat produced by gas and steam turbines, their efficiency is limited and governed by the laws of thermodynamics.
Converting the conventional plants into combined cycle ones can increase their efficiency to around 60%.
