There are two distinctive processes taking place in a boiler system while it is generating steam from water at a particular pressure, temperature, quantity and quality to deliver to its client; be that a turbine, or, a process equipment. First, the chemical energy of the fuel is getting converted in to heat energy. And then this heat energy is getting transferred to water and steam. Therefore, maximum conversion of energy and then maximum transfer would ensure maximum performance. The transfer of heat primarily depends on the available surface area, gas temperature and mass flow of flue gas. We can possibly ensure area availability by using the soot blowers at the right time. In order to ensure proper gas temperature and mass flow, we need to ensure the first job is getting done correctly. That is, maximum conversion of chemical energy in to heat energy at the right place and with optimum air.

The first thing we need to understand that the O2 we measure at APH inlet is actually indicating the unutilized O2 rather than the excess O2. How the air is given is more important to rectify rather than how much air is given in order to optimize combustion. Modulation of SA/ PA ratio, proper biasing of auxiliary air and coal air at various elevations along with proper selection of coal fines would lead to optimization of 3T’s of combustion in the PF furnace. Optimizing SA/ PA ratio in a FBC furnace is equally important along with selecting proper bed height, bed temperature and fuel sizing.

These actions should be taken while calculating the controllable losses, namely; dry gas loss, incomplete combustion loss and the un-burnt losses. There is a potential to reduce the TCL in almost every system I have seen. I am providing a simple saving calculator, which would give you the saving potential when you fill the required data fields that are usually available with you.