The first two units of 115 MW capacity each will be gas-based and the third unit of 120 MW will be steam-based making it the first combined cycle power project in the power-starved State. The Rs 1310 crore fast track project is executed by the Bharat Heavy Electricals Ltd (BHEL) on a turn-key basis for the National Thermal Power Corporation (NTPC).

The trial run of the first unit was successfully completed on January 3 and work is in full swing for the commissioning of the second unit next month, BHEL's site-in-charge, P Arun Kumar, said. The third unit is scheduled to be ready by August this year, he said.

Arun Kumar and A Lodge, NTPC's site-in-charge, are optimistic about the prospects for expanding the capacity of the project. But they have no official communication about Centre's assurance for making this a super power project of 2500 MW capacity. However, it would depend on the establishment of the proposed long terminal at Kochi.

They said there were some minor labour problems but hoped that those would not seriously affect the project schedules.

The Kayamkulam project is unique in more than one sense. This is the first project of its kind in the country set up after raising the level of the site from two metres below sea level to two metres above sea level through dredging, filling and dynamic compaction. The entire plant area was reclaimed by filling 15 lakh cubic metre of sand dredged from the bed of the Kayamkulam Kayal (lake).

Subsequently the load-bearing capacity of the filled up soil was improved and densified by a special technique called dynamic compaction to nullify any effects of liquefaction in case of earth quakes. The entire activity of ground improvement was completed in eight months, recalled Arun Kumar with pride.

The main equipment turbines and generators and the main auxiliaries are placed on concrete pedestals known as inertia block floating on springs. This ensured smooth running of the equipment without absorbing any external shock or vibration. The first gas turbine was test fired on November 1, Kerala formation day, and synchronised on the following day. The unit is operating continuously on base load from November 15.

The gas turbine supplied by BHEL can be run on HSD, naphtha or liquid natural gas. Gas turbine projects, the latest trend, are more attractive due to low capital cost, shorter gestation period, less project space, flexibility in operation, usage of wide variety of fuels and eco-friendliness.

The flue gases that come out at 570 degree celsius during operation of the gas turbines are let into the heat recovery steam generators (HRSG), where water is converted to super heated steam and taken to the steam turbine through pipelines to roll turbo generator and produce further power. Introduction of HRSG, manufactured by the Tiruchirappally plant of BHEL, and steam turbine alongwith operation on combined cycles increase the efficiency of the plant to about 50 per cent, Arun Kumar said.

The gas turbine has been manufactured at BHEL'S Hyderabad plant while the generators and steam turbines were at the company's Hardwar plant. The waste heat recovery steam generators and the digital controls and instrumentation were manufactured at its Trichy plant and Electronics Division, Bangalore, respectively.

In Kerala, BHEL has so far executed the Lower Periyar, Idamalayar and Kallada hydro electric projects for the State electricity board. Two other projects, Kakkad and Peringalkuttu, are in advanced stages of commissioning.