Convention Air Conditioning System is either (i) Process Steam driven Vapor Absorption System or (ii) Electricity driven Vapor Compression System. Both of the aforesaid air conditioning system utilizes high grade energy.
In every fossil fired power plant, huge quantum of low grade thermal heat is available in form of waste flue gas exiting chimney. However key challenge is harnessing low grade heat from flue gas is to design a heat exchanger which can operate at low LMTC and thereby substantially higher surface area without increasing the differential pressure drop.
Based on the above concept, Flue Gas Waste Heat based for Air Conditioning (FGWH-AC) has been developed. As the primary thermal energy is virtually free of cost, the life cycle cost of air conditioning is very low.
DEMONSTRATION PLANT
NETRA has developed, designed and setup Two such systems:
(i) 100 TR FGWH-AC System at Ramagundam. It is in operation since 2013.
(ii) 400 TR FGWH-AC System at TalcherKaniha. It is in operation since 2017
TECHNOLOGY BRIEF
Flue gas tap off is taken from ID fan outlet and drawn in a slip stream where Gas-to-Water heat exchanger is provided. In the heat exchanger, heat is transferred from flue gas to generate hot water. A booster “flue gas fan” (FG Fan) with Variable Frequency drive (VFD) is also provided in the slip stream duct. The VFD regulates the FG fan speed and controls hot water temperature by modulating the flue gas flow. Vapor Absorption Machine (VAM) of 400 TR capacity is connected to hot water loop. This hot water heat is utilized in VAM to generate chilled water. The chilled water is circulated through AHUs to produce Air-Conditioning in ESP & VFD Control Rooms. The system is designed to operate in fully automatic mode through PLC. A backup steam heat exchanger is provided in case of non-availability of flue gas.