Second Evap Cooler for Gujarat State Energy Generation (GSEG), India

Background
One of the first retrofit intallations of an evaporative cooler for a gas turbine (GT) application in India was performed in 2006. The power station owned by Gujarat State Energy Generation Ltd (GSEG) is located in Surat district near the village Mora. The station supplies part of the power to the public power net. Due to the increasing power demand from the public cities, the owner was forced to ensure sufficient power generation during very hot periods in summertime.

PreCooler Solution

Design
The installed gas turbine GT8C (2 units) is part of a 156MW CCPP. The cooler was installed (on one unit) upfront the filter stages, after existing weatherhoods had been removed.
Munters signed a turnkey-contract including design, engineering, supply, errection and commissioning and performance testing. The stainless steel frames were manufactured in India based on the Munters design drawings. Control panel and electrical equipment were supplied from offshore as well as high-efficiency droplet separators made from PP and the Mighty Edge CELdek® cooling pads.

Installation
Munters received the contract midth of November 2005 and delivered all equipment in February 2006. After installation of the cooler in March the cooler was commissioned immediately. The temperature decrease of 10.3° (35.7°C down to 25.3°C) was achieved on a day with 49.6% ambient realative humidity (r.H.). In August a Munters performance test showed a pressure drop of 75Pa only. Even during lower temperatures, the power increase is about 2MW (see figure) at about 5 °C cooling.

Benefits
Now the inlet air temperature of the gas turbines is kept below 28°C that prevents the gas turbines from the high degradation caused by hot air experienced earlier. GSEG has also issued an order for the retrofit of the second gas turbine in the meanwhile.
In early 2007, Munters received the contract for the second gas turbine which was delivered and installed in mid 2007.