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.
There are many opinions on the best way to clean a steam boiler. One of the oldest ways is to dissolve a pound of tri-sodium phosphate (TSP) and a pound of caustic soda (lye) in water and pour it into the boiler. Let it cook for a few hours and then drain the boiler. If you can't buy TSP in your town, try a commercial soap called MEX. It works well and will not damage the rubber gaskets found in some boilers. However, before you clean any boiler, check the manufacturer's instructions for their recommendations.
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℃.
Few parameters critical to health of the Boiler are
(4)Heat rate of the Boiler. This is a composite index of many performance indicators. Most of them will appear below.
(5)Unburnt fuel in flue gas and at boiler bottom .
(6)Flue gas furnace exit temperature.
(7)Boiler tube metal temperatures.
(8)Oxygen in flue gas.
(9)Imbalances in flue gas temperature over a cross section.
(10)Spray water consumption in Super heater and Reheater.
(11)Heat radiation from insulation.
The above all affects the performance of the boiler.
The coal-fired steam boiler is a forced circulation high-pressure single-tube DC boiler. Its operation process includes three processes: the combustion process of the fuel, the heat transfer process of flue gas to water and the vaporization process after water absorbs heat. In order to better control these different processes, the control system should make
the heat of pulverized coal combustion adapt to the requirements of steam load changes and dryness.
Generally, there is moisture in heat medium oil. And, the moisture will be evaporated during the heating process of the oil. If the water vapor is not discharged from the thermal oil heater, it will cause the fluctuation of heat medium oil pressure. However, the oil-gas separator can separate the water vapor from the heat medium oil and discharge it from the heater, which ensures the stable oil pressure.
The coal-fired boiler refers to the boiler uses various types of coal as fuel and converts the heat of coal to steam or hot water.
There are generally two calculation methods of the circulating water volume of a coal-fired hot water boiler. One is to calculate the hourly water volume of one square meter and the other is to calculate the design parameter volume of every ton. As for the make-up water volume of this type of boiler, it is usually calculated as 1% to 3% of its total circulating water.