POWER PLANT TECHNOLOGY
The power plant is ideally located close to Sidhnai Barrage at Abdul Hakim and connected with Pakistan’s highest voltage transmission 500 KV line connecting Multan and Gatti. Power Plant consists of Siemens V.94.2 Gas turbines and Steam Turbine ( in 2+2+1 combined cycle configuration) and is designed for base load operation.
The power block consists of two Siemens V94.2 dual fuel gas turbines primarily operated on natural gas with distillate fuel as backup in case of natural gas unavailability and one condensing steam turbine with associated generators. Combustion air is provided by a pulse-air self-cleaning filtration system. The exhaust gas passes through a diverter damper either to the bypass stack during simple cycle mode or through the NEM Heat Recovery Steam Generators/boilers during combined-cycle operation. The steam turbine consists of a single-pressure single-flow HP section and of a double-flow LP section. Power Plant operates with minimum emission levels in accordance with international standards and guidelines.
Plant was initially designed and commissioned to operate by burning residual furnace oil while diesel was backup fuel. In 2003 government of Pakistan allocated 85 MMCF of natural gas per day and subsequently Plant was converted to gas fuel and commissioned on gas in January 2004. SNGPL is supplying natural gas to Rousch Power Plant under GSA through its network at a pressure between 600-650 psig. Due to its location and efficiency Rousch Power Plant is among few top merits order IPP’s and mostly operated without any interruption at base load.
The Cooling Water used in the plant for condensing wet steam exhausted from the steam turbine in condenser and cooling of other plant auxiliary equipment. Water is drawn from the Fazil Shah Feeder through a submerged concrete inlet channel to a treatment area and then to the water storage area from where it is supplied to circulating water system, de-mineralized water treatment plant and potable and service water systems. De-mineralized water is used as makeup water for heat recovery steam generators. Plant has waste water treatment system and wastewater is discharged after treatment conforming to the NEQS limits into the Fazil Shah Feeder. The remainder of the auxiliary plant and systems are cooled by a closed circuit water system using de-mineralized water.
I & C CONCEPT
The Rousch Power Plant is equipped with Siemens state of the art distributed control system TXP. Control system provides all key plant information, trending, operating commands, alarms, plant history and protections at operators’ desks in control room enabling engineers and operators to control all plant operations from central control room. The operations management level is made in a redundant configuration with all key plant protections with 2 out of 3 logic to increase Plant reliability and minimize the risk of Plant tripping of false alarms.
The turbine generators supply power to national grid through 11KV/500 KV unit transformers and gas- insulated switchgear to the 500-kV switchyard – an outdoor type substation with one and a half breaker method using SF6 circuit breakers. Two unit auxiliary transformers provide the plant auxiliary power supply from the generator leads to the 11-kV unit switchgear related to each gas turbine generator set. In the event of the grid failure, the 3000-kVA black-start diesel generator set provides power to the most essential equipment for the black-start of one gas turbine generator set. Rousch Power Plant is among only few power plants, which have black start capability and can energize national grid in case of country wide power failures and blackouts.
O & M CONCEPT
Rousch Power Plant since its commissioning has adopted a prudent and robust plant O&M strategy. Since its conversion from heavy fuel to natural gas fuel our focus has been to achieve highest availability and reliability levels with economical and efficient plant operation. Our O&M strategy has resulted in top decile performance consistently over the years. Gas Turbines have already completed more than 125,000 Equivalent Operations Hours. In order to insure highest level of performance over the next 100,000 operating hours, the life time extension (LTE) measure which included replacement of all major components of gas turbines and compressors were performed in 2012 for the first time in Pakistan on Siemens V.94.2 machines by Siemens AG Germany i.e the OEM of gas turbines. The picture gallery contains some of the pictures of this mega event.