This part describes the varied sorts of Boilers: Hearth tube boiler, Water tube boiler, Packaged boiler, Fluidized Bed Combustion Boiler, Atmospheric Fluidized Mattress Combustion Boiler, Pressurized Fluidized Bed Combustion Boiler, Circulating Fluidized Bed Combustion Boiler, Stoker Fired Boiler, Pulverized Gas Boiler, Waste Warmth Boiler and Thermic Fluid Heater. In a Boiler fuel is burnt to get heat energy which is transformed from chemical energy saved in a gas. Water comes Water Tube Boiler to water wall from Boiler drum, and circulated back to drum after absorbing heat. During circulation of water in tubes, steam is generated and picked up on the higher a part of the Drum. Ash which is produced within the Boiler because of combustion of strong gasoline is collected at Boiler bottom and also in Economizer, Air Pre-heater and ESP. So by charging steam in Deaerator water temperature will increase and soluble gases in condensate departs.
This results in decrease in drum degree and Feed Control valve will open more to compensate the Drum level to Normal water level, which ends up in overloading of Boiler Feed pump. If tube has failed inside boiler then hissing sound comes and it may be seen from outside. At the time of Islanding, Generator will observe the load linked in this Unit and the Governing Management Valves would close based on load and permit the steam to move via Turbine. The surplus quantity of steam will remain in Boiler which increases the Drum strain.
After ensuring the reason, close the start-up vent and dump the excess steam in Condenser. If warmth supply to Boiler will probably be increased instantly with an enormous amount then it impacts the drum stage and it swells. When stand-by Boiler feed water pump has began with running Boiler feed water pump, then Drum stage will increase as a result of at that opening in Boiler feed Management valve when feed water pressure will increase, more feed water flows to drum because of that opening of management valve and results in enhance in drum level. This case usually happens throughout scheduled Equipment change over of Boiler feed water pump.
If flue fuel inlet temperature reduces then it steam era reduces in Boiler and pressure drops. This needs to be observed very rigorously and the generator Load set level has to be lowered, in any other case the TG will trip when the Foremost steam stress becomes low. If as a mal operation Load set point at Generator is given more than steam generation then Boiler stress decreases. If steam movement is at decreasing pattern and feed water flow is at rising pattern then it indicates that tube has failed.
Donot shut the Feed Control valve totally if drum degree rises because if the control valve is closed utterly, the feed water in Economizer tubes, which was passing to Drum, will turned steam due to heat in flue fuel and when feed water supply by way of Economizer will likely be once more established by Feed control valve then hammering in Economizer tubes as a result of presence of steam.