ABSA 3B2 Questions

ABSA 3B2 Questions And Answers A gas turbine has a ... - high power to weight ratio A overspeed trip is an integral part of the governing system in that it ... - prevents steam from entering the turbine if the speed gets too high Absorption vs compression - Aftercoolers cool the air .... - significantly below the dew point An uncoated copper line may be installed on a system up to what OD - ??? At what rated speed is the gas turbine started at ... - 55% Benefits of axial compressor - 10% more efficient then centrifugal Benefits of intercooling - decrease as pressure ratio increases Benefits of using natural gas in gas turbine ... - efficient combustion and clean burning Centrifugal compressors - accelerlate the velocity of a gas and then convert it to pressure Coagulation is - neutralization of particles to attract each other Colloidal particles are measured in - angrstrom Condenser safety devices - atmospheric relief device and high water level Disadvantages of hairpin exchanger - lots of places for leaks Fired heaters can be - direct or indirect How much power is used to run the compressor - 66% Hyperbolic depend on ... for cooling - water spray or density differential of air If the engine speed increase the turbocharger - increase speed and provide more air for combustion In a reaction turbine stationary blade what occurs - velocity increases Pressure drops In a reaction turbine when the steam from the station blade is admitted too the moving blade what force does the steam exert - impulse force on the blade and blade shape creates a reaction force In an aero-derivative gas turbine what does the scavenge system do - returns oil from the bearings to the supply Love compressors use - timing gears Main purpose of air receiver - dampen pulsations and allows moisture to drop out Moisture in the system can cause - freezing and plugging of the expansion Most efficient coolant for refrigerant - water cooling Oil pressure cut-out - shuts down the compressor when oil pressure drops below a minimum limit On an electroic overspeed, the turbine won't trip until ____ sensors sense an overspeed condition - 2 Purpose of a dummy piston on a steam turbine - exert a thrust force on the piston ion the opposite direction to normal thrust force Purpose of a turning gear - prevent hogging Purpose of purging - remove NCG Purpose of the HP cut-out is to ... - stop the compressor before the pressure relief device release Purposes of oil systems - lubricate and cool Reciprocating compressors are divided into types according to .... - single or double acting and cylinder arrangement Refrigerant is added ... - between the liquid shutoff valve and expansion valve Refrigerant is classified by ... - flammability and toxicity Speed sensitive governors - mechanical mechanical hydraulic electric hydraulic Surge will occur - when the pressure rises above the surge po