Pressure Vessels and Engines MCQ with Answers

remain unaffected

improve

worsen

may improve/worsen depending on size

unburnt carbon in ash

incomplete combustion

ash content

flue gases

supply of excess, air

supply of excess coal

burning CO and unburnts in upper zone of furnace by supplying more air

fuel bed firing

inherent moisture and surface moisture are different things

in some coals moisture may be present upto 40%

some moisture in coal helps in better burning which is not possible with completely dry coal

it increases thermal efficiency

cavitation of .boiler feed pumps

corrosion caused by oxygen

heat transfer coefficient

pH value of water