Related Questions

Which of the following advantages is not associated with the use of preheated air for combustion of a fuel in the furnace?
A Increase in calorific value of the fuel
B Increase in flame temperature
C Reduction in scale losses
D Saving in fuel consumption
Which of the following is not increased by using preheated combustion air in place of ordinary air at room temperature?
A Calorific value of the fuel
B Flame temperature achieved
C Speed of combustion of fuel
D Heat transfer rate to the stock in the furnace
Use of preheated air for combustion of fuel in the furnace, increases the
A Scale losses of the furnace stock
B Calorific value of the fuel
C Flame temperature
D None of these
Use of excess of combustion air in the combustion of fuels results in
A Heat losses
B Long flame
C Condensation of water vapour from the fuel gas
D None of these
Deficiency of combustion air during combustion of a gaseous fuel
A Lengthens the flame
B Causes heat loss of fuel by its partial combustion
C Both A & B
D Shortens the flame
Fuel gases containing hydrocarbons (ie.g. coke oven gas) are not preheated before burning, mainly because
A The hydrocarbons crack thereby choking and fouling the heat transfer surface by carbon soot
B It reduces its calorific value tremendously
C It reduces its flame temperature tremendously
D There are chances of explosion during preheating
In a furnace operation, which is not preheated?
A Solid fuels
B Hydrocarbon containing fuel gases (e.g. coke oven gas, refinery gas etc.)
C Both A and B
D Neither A nor B
Advantages of fluidised bed combustion are
A Reduced NOx formation in flue gas
B Lower furnace operating temperature
C High heat transfer rate
D All of the above
The most commonly used combustion system manufactured in India for the thermal power plant boilers is the __________ combustion system.
A Pulverised fuel
B Travelling grate stoker firing
C Circulating fluidised bed
D Fluidised bed
The combustion efficiency of a gas turbine using perfect combustion chamber is of the order of
A 75%
B 85%
C 90%
D 99%

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