Gas Turbine

Types of ventilation – Induced draft ventilation – Turbine ,Acc module – Positive ventilation- LGB, Exhaust Ventilation System Design features †¢ Induced Draft Ventilation †¢ Number of compartments †¢ Accessory compartment †¢ Turbine compartment †¢ Aft compartment †¢ Generator Enclosure †¢ 2 X 100 % Roof mounted centrifugal fans †¢ Auto change over †¢ Fan outlet gravity dampers, CO2 dampers and silencers provided †¢ Enclosure Air inlet hoods with filter panels †¢ Slow cool down fan provided for Turbine compartmentFan sizing Accessory compartment Heat load criteria: †¢ Q = Heat Rejection = 104000 (BTU/Hr) = 436. 8 ( Kcal/min) †¢ Design compartment temp – 600 C at ambient of 430 C †¢ Fan provided : 2 x 10,000 CFM at 3. 5 inch WC static pressure †¢ The calculated temp raise with selected air flow 7. 80 C †¢ Static Pressure selected considering drop across suction filter, inlet, ex it, silencer and ducting Number of air changes criteria: †¢ Volume Of the Acc Comp = 278 m3 †¢ Number of Air change/Hr = 60 (Meets NFPA and DEP 31. 29. 70. 31 requirements)Fan sizing Turbine compartment Heat load criteria: †¢ Q = Heat Rejection = 1273469 (BTU/Hr) = 5348 ( Kcal/min) †¢ Design compartment temp – 1200 C at ambient of 430 C †¢ Fan provided : 2 x 26,000 CFM at 3. 5 inch WC static pressure †¢ The calculated temp raise with selected air flow 300 C †¢ Static Pressure selected considering drop across suction filter, inlet, exit, silencer and ducting Number of air changes criteria: †¢ Volume Of the Acc Comp = 215 m3 †¢ Number of Air change/Hr = 185 (Meets NFPA and DEP 31. 29. 70. 31 requirements)Vent Fan Drawing Typical Accessory Compartment Fan Curve †¢ Fan BHP : 5. 53 kw †¢ Motor selected- 8 kw †¢ Motor Data: †¢ 4pole – 415V,3Ph TEFC †¢ Motor ambient Temp. 650 C †¢ Insulation class â₠¬â€œ H ( Temp raise limited to class B) †¢ Flame proof NEC Class 1 Div 2 Gr C&D Turbine Compartment Fan Curve †¢ Fan BHP : 15. 45 kw †¢ Motor selected- 19 kw †¢ Motor Data: †¢ 4pole – 415V,3Ph TEFC †¢ Motor ambient Temp. 650 C †¢ Insulation class – H ( Temp raise limited to class B) †¢ Flame proof NEC Class 1 Div 2 Gr C&D Exhaust Frame Blower (Fr6) †¢ †¢ †¢ †¢ †¢ Two motor driven centrifugal Blowers Inlet screen & silencer Air to turbine shell, exhaust frame via strut passages (Annular space) Flow:2470 CFM with two fans in operation Emergency:1860 CFM with one fan in operation Motor rating :50HP GT Auxiliaries GT Auxiliaries EXHAUST FRAME BLOWERS EXHAUST FRAME BLOWER GT Auxiliaries MIST ELIMINATOR Removes oil mist entrained in the LO vapor – Flow rate 😕 SCFM – Demister pads(8No’s)-SS316 wire mesh – Coalescing filter element(99. 97% for droplets and particles 0. micron a nd larger) – Outlet oil content not more than 5ppm by weight – Centrifugal blowers (2 No’s) and motors(11kw each) OUT LET FILTER CASING INLET BLOWER & MOTOR GT Auxiliaries GT Auxiliaries MIST ELIMINATOR – High speed rotating machinery: High temperature and shearing action in bearings generates a large volume of very fine oil mist (droplets) plus a considerable amount of vapor – Oil mist and oil vapor is vented from the lube oil tank, it causes a visible plume – Stringent environmental laws and regulations at all government levels – Coalescers combine small aerosols through the filter media to form large droplets.