Regular inspections can identify and correct faults in the safety systems that are designed to prevent accidents.
When it comes to regular maintenance, the cost of the inspections and repairs will be dramatically lower than the loss of time and profit from a broken boiler that requires replacing. Don’t let maintenance fall by the wayside. Schedule it at even intervals throughout the year.
Normally a boiler is provided with two independent sensors for emergency low water level burner cut-outs. So this would never happen. However, if it does, don't take any chances! Shut off the burners immediately!
Before you start raising the level in the boiler you have to find out if any part of the furnace walls has been overheated. If you raise the level over a glowing steel-wall then the boiler might produce more steam than the safety valves can handle and a nasty explosion would be the result.
Soot on the heating surfaces. Even a thin layer of soot will reduce the boiler efficiency. Not the right fuel for the burner. For instance, diesel oil to a rotary cup burner wouldn't do. Too low feed water temperature.
The condensing boiler burns carbon-based fuel with oxygen in order to produce steam and carbon dioxide. The gases that escape this process (through a chimney) as exhaust are called flue gases. The major advantage is that they offer up to a 90% improvement in terms of efficiency when compared to standard gas boilers. Overall, condensing boilers are considered much more efficient in contrast to non-condensing gas boilers, a major consideration for any business running on a budget.
It could also say, how much heat is required to rais the water temperature from 60 ℃ to 90 ℃.
To calculate heat required follow below steps
Q= mCp dt
Where
m - water flow rate (kg/hr)
Cp- specific heat of water
dt- temperature differences ( 90–60)
You will get heat required in kcal/ hr.
dividing to Q by fuel GCV and system efficiency you will come to know how much fuel (either it is coal or oil) required to raise the temperature of water from 60 ℃ to 90℃.
For same energy output when energy input is lesser efficiency increase. When maximum heat energy is generated from coal or losses in heat transfer are reduced efficiency increase. Coal in boulder size is burnt combustion may not be complete. There will be more unburnt coal. As per coal chemistry and as per boiler flue gas velocity as designed best coal size for full combustion is designed. Maximum crushed coal is also not the best. Then there will be more coal dust. According to general design in various technologies pulverized coal give best combustion for fbc boilers. For cfbc boilers generally crushed coal size is 6 mm.
When you achieve best combustion mean this is main contributor for increase in efficiency. Boiler design, heat transfer, flue gas velocity, heat losses, are other factors for efficiency.
If the following three conditions occur during the burning and flame out process of a gas-fired boiler, the furnace is likely to blow up.
1.The residual gas content in the furnace reaches the ignition limit at the start-up phase of the furnace.
2.The fuel content in the furnace reaches the ignition limit after several times failure of ignition.
3.The fuel is sprayed out because of the halfway extinction of the flame. And, the temperature of the furnace can not meet the spontaneous combustion condition of the sprayed fuel. However, the content of the sprayed fuel reaches the ignition limit.
In the work of transforming a coal-fired boiler into a gas-fired boiler, the principle of changing the original boiler should be reduced without changing the pressure component of the boiler body. The transformation process should focus on the choice of gas burners, the determination of the number of burners, the layout of the burners, the matching design of the furnace layout, and the selection of explosion-proof measures. Step by step, both economic benefits and practicality should be considered.
