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Objective & Viva Questions & Answers for preparation of Boiler operation Engineer (BOE) exam & Boiler Interview

1-Why Boiler is considered as explosive equipment / system? Boiler involves the generation of steam at higher pressure & temperature upon release of this into atmosphere could cause disasters. 2-How do you specify the Boilers? Boilers are specified by their operating pressure, temperature, steam generating capacity & even by heating surface. 3-What are the various circuits involved in Boilers? Water circuit, Steam circuit, air circuit & flue gas circuit 4-Write down the various energy used / generated in power plants? Chemical energy (fuel) Thermal energy (Heat present in flue gases & steam) Kinetic energy (rotation of Turbine rotor), Mechanical energy (shaft power on Turbine) Electrical energy (In generators). 5-Why steam, is generated at high pressure & temperature? High pressure & temperatures steam is having more heat content & also has more potential to do work. 6-At what pressure do you carryout Hydraulic test on Boilers?

Boiler calculations for Boiler operation Engineer Exam (BOE)

  1-Oxygen percentage in Boiler outlet flue gas is 4.9%, then what will be the percentage of excess air? We have excess air EA = O2 X 100 / (21-O2)                                    EA = 4.7 X 100 / (20-4.7)                                    EA = 30.71% 2-Calculate the Oxygen level (O2) in flue gas, if excess air is 25% We have Excess air EA = O2 X 100 / (21-O2)                                    25 = O2 X 100 / (21-O2)                                    O2 = 4.2% 3-A Boiler’s combustion system requires 5.5 kg of air for burning 1 kg of fuel, then calculate the total air required for complete combustion if its flue gas has 4.1% of O2 We have, Total air = (1 + EA/100) X Theoretical air EA = O2 X 100 / (21-O2) EA = 4.1 X 100 / (20-4.1) = 25.78% Therefore Total air = (1 + 25.78/100) X 5.5 = 6.92 kg of air per kg of fuel burnt 4-A Coal fired boiler having total heating surface area 5200 M2 produces 18 kg of steam per square meter per hour of heating surface, then calculate the Boiler cap