Based on the exhaust gas analysis, a controller maintains stoichiometric combustion __ a. by commanding a servo motor to adjust the combustion air damper b. By commanding servo motor to adjust the fuel supply valve. c. Both a. & b. d. None of the above.

1 Answer

Answer :

c. Both a. & b.

Related questions

Description : Oxygen trim control strategy __ a. continuously measures the oxygen content in the flue gas b. adjusts the combustion air flow c. Continually tuning the air-fuel mixture. d. All of above

Last Answer : d. All of above

Description : A flue damper and a vent damper are two examples of _______ a. Combustion air positive shut off devices b. Combustion air negative shut off devices c. Both a. & b. d. None of the above

Last Answer : a. Combustion air positive shut off devices

Description : It is easy to detect and monitor excess air a. As oxygen not used for combustion is heated and discharged with the exhaust gases. b. Oxygen is discharged without heating c. Both a. & b. d. None of above

Last Answer : a. As oxygen not used for combustion is heated and discharged with the exhaust gases.

Description : For process boilers , combustion air fans must meet the following requirements ___ a. The fan motor shall be driven by a variable speed drive b. The fan motor shall include controls that limit the fan motor demand to no more than 30 %. c. Both a. & b. d. None of the above

Last Answer : c. Both a. & b.

Description : The economiser is used in boilers to........ A]Increase thermal efficiency of boiler B]Economise on fuel C]Extract heat from the exhaust the gases D]Increase flue gas temperature

Last Answer : A]Increase thermal efficiency of boiler

Description : Combustion is the ideal air/fuel ratio where a. the mixing proportion is correct, b. the fuel is completely burned c. the oxygen is entirely consumed d. All of the above

Last Answer : d. All of the above

Description : Which of the following is the combustion accessory of a boiler? • Fuel oil system • Gas system • Coal system • All of the above

Last Answer : • All of the above

Description : What is the function of boiler? • To burn the fuel in a confined closed system With the supply of air • To generate steam in varying pressure • To generate steam at constant pressure • To produce flue gases by burning fuel at a given pressure

Last Answer : • To generate steam at constant pressure

Description : Boiler works from application of which type of energies 1. Fuel combustion 2. Electricity 3. Nuclear energy 4. All of above

Last Answer : 4. All of above

Description : Presence of moisture in fuel oil would (A) Keep the burner tips cool (B) Aid in proper combustion (C) Because sputtering, possibly extinguishing flame (D) Clean the nozzles

Last Answer : (D) Clean the nozzles

Description : A __________ is a type of heat exchange system where water is heated to its' boiling point via combustion of a fuel blown through a tube submerged in water. a. Condensate loop b. Hyperbolic cooling tower c. Steam boiler d. All of above

Last Answer : c. Steam boiler

Description : Use of ______ is prohibited in process boilers. a. Use of a common gas b. combustion air control linkage c. jack shaft d. All of the above

Last Answer : d. All of the above

Description : Detecting and monitoring carbon monoxide assures the air/fuel ratio is not too rich as a. The excess air is trimmed b. Excess air is let out c. Both a. & b. d. None of above

Last Answer : a. The excess air is trimmed

Description : Fuel economy in an industrial furnace operation cannot be achieved by the use of (A) Stoichiometric combustion air (B) Non-preheated combustion air (C) Combustion air not enriched with oxygen (D) Recuperators

Last Answer : (A) Stoichiometric combustion air

Description : Find false statement about effect of sulphur in fuel? (A) It has heating value (B) It helps in electrostatic precipitation of ash in flue gases (C) It leads to corrosion of air heaters, ducting, etc. if flue gas exit temperature is low (D) It erodes furnace walls

Last Answer : (D) It erodes furnace walls

Description : Which of these is an output of a ‘Furnace’? a. Fuel gas b. Cool Air c. Flue gases d. Water Vapor

Last Answer : c. Flue gases

Description : Combustion air positive shut-off shall be provided on all newly installed _______ a. Grant boilers b. Process boilers c. Worcester boilers d. All of the above

Last Answer : b. Process boilers

Description : Higher efficiency in the combustion of solid fuel cannot be achieved by (A) Proper fuel preparation (B) Keeping the flue gas exhaust temperature very high (C) Adopting efficient-fuel firing technique & equipment (D) Supplying correct quantity of combustion air

Last Answer : (B) Keeping the flue gas exhaust temperature very high

Description : A safety valve usually employed with stationary boilers is (A) Lever safety valve (B) Dead weight safety valve (C) High steam and low water safety valve (D) All of these

Last Answer : (D) All of these

Description : A device known as a _______ is used to release condensate from the pipework whilst preventing the steam from escaping from the system. a. Steam traps b. Steam pipes c. Boiler nose d. Release valve

Last Answer : a. Steam traps

Description : Combustion of which fuels from following is source of heat for boiler 1. Wood 2. Coal 3. Oil 4. All of above

Last Answer : 4. All of above

Description : Boiler is a enclosed vessel that provides a) Expansion b) Ignition c) Combustion d) None of the above

Last Answer : c) Combustion

Description : Basic Parts of a Boiler. Burner, • the combustion chamber, • the heat exchanger • All of the above

Last Answer : • All of the above

Description : A boiler is an enclosed vessel that provides a means for ________ and ______ heat to water until it becomes hot water or steam. a. Generate, boiler b. Condenser, loop c. Combustion, transfers d. All of above

Last Answer : c. Combustion, transfers

Description : Which of these is a ‘fissile fuel’? a. Thorium b. Carbon c. Potassium d. Graphite

Last Answer : a. Thorium

Description : Industrial boilers are closed vessels that use a fuel source or electricity to generate ________for industrial purposes. • Fuel Food • Steam

Last Answer : • Steam

Description : A _______ incorporates a firebox or furnace in order to burn the fuel and generate heat. • Steam • Boiler • Hydrogen • None

Last Answer : • Boiler

Description : A -________ incorporates a firebox or furnace in order to burn the fuel and _________ heat. a. Boiler, generate b. Heat, boiler c. Steam, pressure d. None

Last Answer : a. Boiler, generate

Description : A _______ incorporates a firebox or furnace in order to burn the fuel and generate heat. A Steam B Boiler C Hydrogen D None

Last Answer : B Boiler

Description : Boiler efficiency is a measure of how effectively _______ energy in fuel is converted into heat energy in steam going to the turbines A Chemical energy B Heat energy C Thermal energy D All of the above

Last Answer : A Chemical energy

Description : An economiser in a boiler........ A]Increases steam pressure. B]Increases steam flow C]Decreases fuel consumption D]Decreases steam pressure

Last Answer : C]Decreases fuel consumption

Description : The biggest loss in the boiler is a) Moisture in fuel b) Dry flue gases c) Steam formation d) Unburnt carbon

Last Answer : b) Dry flue gases

Description : __________ the exhaust gas is an indication of the incomplete combustion of fuel. (A) Low temperature of (B) High temperature of (C) High % of CO in (D) High % of CO2in

Last Answer : (C) High % of CO in

Description : when steam is condensate volume is drastically……. a) reduces b) increase c) both a) & b) d) None of above

Last Answer : a) reduces

Description : If the water level inside the boiler were not carefully control cased… a) explosion b) overheat and fail c) both a) & b) d) None of above

Last Answer : c) both a) & b)

Description : The heat produced in this system is then rejected into the system as _______ a. Steam b. Boiler c. Both a & b d. None

Last Answer : a. Steam

Description : The stoichiometric air fuel ration for petrol is 15:1 . What is the air fuel ratio required for maximum power? (a) 16:1 – 18:1 (b) 15:1 (c) 12:1 – 14:1 (d) 9:1 – 11:1

Last Answer : Ans :c

Description : Velocity of flame propagation in SI engine is maximum for a fuel air mixture which is (a) 10% richer than stoichiometric (b) Equal to stoichiometric (c) More than 10% richer than stoichiometric (d) 10% leaner than stoichiometric

Last Answer : Ans :a

Description : Smoke is produced due to (A) Insufficient supply of combustion air and insufficient time for combustion (B) Poor quality of fuel and improper mixing of fuel & combustion air (C) Poor design & overloading of furnace (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Stoichiometric combustion of 12 kg of carbon requires __________ of oxygen. (A) 1kg mole (B) 22.4 Nm3 (C) 32 kg (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Direct relation between…….. &………of saturated steam, the amount of energy input to process easy to control. a) volume, pressure b) volume, temperature c) temperature, pressure d) None of above

Last Answer : c) temperature, pressure

Description : The product of efficiency & heat transferred to the working fluid is? a. Net temperature change b. Net work done c. Net enthalpy change d. None of the mentioned

Last Answer : b. Net work done

Description : In a steam condenser, the partial pressure of steam and air are 0.06 bar and 0.007 bar respectively. The condenser pressure is (A) 0.007 bar (B) 0.053 bar (C) 0.06 bar (D) 0.067 bar

Last Answer : (D) 0.067 bar

Description : Green coal, in order to be burnt, must be (A) Heated sufficiently (B) Burnt in excess air (C) Heated to its ignition point (D) Burnt as powder

Last Answer : (C) Heated to its ignition point

Description : What is the reason to service a cooling tower? a) to ensure proper air flow b) to clean the tubes c) to inspect the water pump d) all of these

Last Answer : all of these

Description : What happens when air dissolves in condensate? a) non corrosive b) temperature of air increases c) corrosive d) none of above

Last Answer : c) corrosive

Description : Steam is regularly used for propulsion (as a driving force) in applications such as ________ turbines. • Gas turbine • Steam turbine • Water turbine

Last Answer : • Steam turbine

Description : When gas changes to liquid through the process of condensation, the temperature A] Increases. B] Decreases C] Remains constant. D] None of the mentioned

Last Answer : C] Remains constant.

Description : In a condensation process, _______ to _________ A] Gas, Solid B] Gas, Liquid C] Liquid, Gas D] Liquid, Solid

Last Answer : B] Gas, Liquid

Description : Furnace pressure is normally controlled by regulating the (A) Air pressure (B) Fuel gas pressure (C) Speed of I.D. fan (D) Damper

Last Answer : (D) Damper