The coolest power in the district23 April 1999
Experience with successful completion of the power and district cooling system at the new Kuala Lumpur International Airport provides lessons for future projects.
The use of gas turbines to provide both heat and electricity has been well established. Rather less well-known is the use of gas turbines for power and cooling. One example of such an installation is at Kuala Lumpur International Airport (KLIA). This project provides 40 MWe through two gas turbines, and 80 MWth through 9 steam absorption chillers.
The project originated when the government of Malaysia and Kuala Lumpur International Airport (KLIA) invited bids for the concession to build a BOT cogeneration plant to supply chilled water for the airport facilities, with the excess electricity being sold to the airport operator. Other key requirements included optimisation of local companies and technology transfer.
There are three basic elements to the plant system:
This consists of two 20 MW gas turbines, and two heat recovery steam generators (HRSG) capable of processing 40 tons per hour of process steam.
District cooling plant
This consists of steam absorption chillers using steam produced from the HRSGs, and a chilled water distribution pipe network.
This consists of air coolers, auxiliary steam boilers, and water/oil storage tanks.
The plant work was split into four contract packages:
The first phase of the project was designed to enable the airport to handle 25 million passengers per year (mppa), which is the astimated flow by 2012. The second phase of the project will be initiated with the development of the planned Satellite B building, which will enable the airport to handle 45 mppa.
Phase 2 is due for completion by 2012. This phase consists of the following:
Electrowatt Engineering claims that the average achieved levels of plant availability are 100 per cent for the district cooling plant, and 97 per cent for the cogeneration plant. For the district cooling, 100 per cent availability is important, in order to prevent any discomfort to people in buildings supplied with chilled water. For the cogeneration plant, 97 per cent availability is acceptable, and allows downtime for equipment maintenance. Despite the 3 per cent downtime, power to the customer is not affected as supply is obtained from the national grid.
Recently, an absorption-type chiller driven by gas that has the capability to provide either heat or chilled water (although not both at the same time) has been developed. However, while this is a potential option, it is seldom exercised, due to the increased cost. There is currently one project in Switzerland which may take advantage of this new combined type of absorption chiller.
The Kuala Lumpur plant uses natural gas as the primary fuel, with Jet A-1 as a back-up fuel in case of gas supply disruption.
The plant is capable of producing 40 MWe. Currently, the plant exports 27 MWe to the KLIA grid, while another 6 MWe is consumed internally for plant equipment use. The average chilled water temperature is 6-7°C.
The installed gas turbine is a GE LM2500, manufactured by General Electric and packaged and installed by Ishikawajima Harima Heavy Industries, together with the local contractor Equator Engineering.
The HRSGs are being manufactured, installed and commissioned by Mechmar Engineering and Stork Ketels.
The district cooling plant is designed to provide 27 500 tons of chilled water for air conditioning purposes. The plant can be further expanded should the need arise.
The most challenging elements of the project were:
There were three key design decisions:
Fuel. In the case of KLIA, adequate supplies of gas are available at an economic price.
Electrical power. The price is important as electrically-driven centrifugal chillers can be economically beneficial when used in conjunction with steam-driven gas absorption chillers.
Loading profiles required for chilled water. These have to be carefully estimated to design the chiller ratings for maximum hourly requirements. In the case of KLIA, information was also assessed with the help of data available from other airports.
In the event, the plant has satisfied both the chilled water and electricity requirements of the airport, and the airport operator has praised the good and reliable performance of the plant.
While the project was completed on time, problems did occur, and these gave valuable lessons for the future. These included:
| b-august-october-1994-b-electrowatt-engineering-provide-technical-services-and-support-to-gas-district-cooling-during-preparation-of-proposal-submitted-14-10-94-b-april-1995-b-kl-international-airport-award-gdc-a-20-year-concession-to-build-own-and-operate-a-cogeneration-district-cooling-plant-b-april-1997-b-first-chilled-water-supplied-to-airport-b-july-1997-b-electrowatt-engineering-completed-its-assignment-b-june-1998-b-airport-opens-td-tr-table-br-brTablesBasic data Other district cooling orders received by EWE:
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