Initially, about 230 acres land for the Power Station and 164 acres for residential colony was levelled and subsequently construction was started. Later on contracts with Chinese firm, M/s. CMEC, were signed for three units in two stages - Two Units each of 210 MW and one unit of 320 MW. In this way a power complex emerged which is going to be the biggest of all Thermal Stations in Pakistan with the possibility of construction of two more units. Presently, the total generation capability of three phases is envisaged as 1,370 MW.
Phase - 1 (Units 1, 2 & 3)
This phase consists of three steam units each capable of generating 210 MW electricity. The supplier started delivery of equipment to site in January, 1989, and after pre-assembly of equipment at Site, erection started in July, 1990. Unit No. 1 was commissioned in September, 1993 and Unit No. 2 in March, 1994.
It contains the turbine hall having a span of 45 meters and dearator bay, 12 meters wide. The steam turbines which drive generators are of three stages condensing type arranged transversely to the axis of turbine hall. The operational platform is at elevation 12.6 meters and a maintenance bay at ground floor near Unit No. 1. The power plant is designed on the block principle: boiler-turbine-generator-unit transformer. The fuel gas exhaust section of two units is connected with a 200 meter high stack, outer section of which is a 195-meter high concrete shell.
Fuel & Oil Facilities
Fuel oil facilities are constructed for decanting, oil storage, preparation and supply of fuel to boiler nozzles. It also include HSD storage as well as oil facilities for reception, storage, purification and centralised delivery of turbine oil and insulating oil to power plant.
The cooling water used in condensers is re-circulated in closed cycle with inducted draft cooling towers. The water is being cooled for each unit in two cooling towers each consisting of eight fans. Two cooling towers carry 27,500 Cu m/h circulating water for condensers of one unit.
One startup boiler using diesel oil as fuel with steam output of 50 t/h is provided to meet steam requirement for initial start of unit as well as a backup of power plant auxiliaries. A separate stack of 30-meter high has been constructed for it.
The electricity generated at 15.75 KV is brought out from Unit transformer at 220 KV and fed to the National Grid via a switchyard. Power Plant auxiliaries are fed at 6.6 KV.
Phase-II (Units 5 & 6)
It consists of two units of 210 MW each having equipment similar to Phase-I. Turbines are placed longitudinally in main building. Outdoor boilers exhaust of two units is connected to one stack.