Gas District Cooling, Co-generation System

Written by Fathiah Zakaria

Kuala Lumpur City Center (KLCC), Kuala Lumpur International Airport(KLIA), and Putrajaya are among the high profile development area and national icons that used co-generation system to provide electricity and chilled water (air-conditioner) [1]. Gas district cooling use a central source to supply cooling to a number of buildings instead of multiple individual air conditioner system. This solution provides a very energy-efficient system which offers operating flexibility, noise and vibration free.

Co-generation system is self-generating electricity and re-uses waste heat to maximize overall process efficiency. Co-generation is a scenario where simultaneous production of two kinds of energy (electricity and steam) from the same source at the same time. Electricity is generated from the gas turbine. Waste heat from the gas turbine exhaust is channelled to a waste heat boiler to generate steam which is used as primary energy source to generate chilled water. An Auxiliary Fired Boiler is also installed to supplement steam production needed to produce chilled water [2]. The overall co-generation system is illustrated as in figure below.

Chilled water will be distributed through an underground piping system to heat exchangers in buildings. The heat exchangers are used to transfer the chilling energy from the water to the internal building. Cold air is then dissipated within the building via a typical fan coil unit and air handling unit. Then, warm water returns to the heat exchangers for a continuous closed loop cooling process again.

By utilizing the heat from the gas turbine to produce steam, the co-generation system is able to improve the overall efficiency of the plant. If you have chances to be in the KLCC and Putrajaya perimeters, don’t forget to have a look at the buildings which have a big amount of steam come out from the rooftop, it might be a Gas District Cooling plants!

References

[1] “Gas District Cooling” Accessed on: 30 October, 2019. [Online]. Available: https://www.gdc.com.my/

[2] “Co-generation system” Accessed on: 30 October, 2019. [Online]. Available: https://www.gasmalaysia.com/index.php/our-services/new-technologies/combined-heat-power/introduction