ABSTRACT
The field of boiler controls is an advancing rapidly especially since the introduction of distributed digital systems, the latest in a long string of advances. However, the basics of boiler control are straight forward and subject to less change. The purpose of the boiler safety control system is to prevent explosions and other damage to the boiler. If an accumulation of unburned fuel vapor suddenly ignites, explosive levels of energy can be released and cause severe damage to the boiler and surrounding countryside. The energy is supplied to the boiler by the combustion process and the combustion control system regulates the firing rate by controlling amount of air and fuel delivered to the burners. Feed water control must be able to regulate water level under very dynamic conditions when the heat rate changes in the boiler causes the water level to shrink and swell, due to steam bubble volume changes in response to firing rate changes.
