Abstract: While it is possible to operate and control a boiler with indicators and recorders alone, efficient and reliable operation through simple control is not optimal these days. Early boilers were smaller and operated with simple, but rising demand for, and cost of, steam production has resulted in larger boilers with increased output. More careful boiler control calls for process instrumentation. Air control is inaccurate and unreliable, particularly when flow rates drop below 25% of maximum load. Traditional control methods set the fuel-air ratio .This solution cannot correctly compensate for process variables and is slow to respond to varying load conditions. This control element cannot be solely depended on for accurate control. The goal of airflow optimization is to minimize thermal losses and prevention of a starved boiler. Minimizing excess air reduces stack temperature and thermal loss and can only be done utilizing high accuracy airflow measurement devices. The fuel saving potential in a boiler can exceed 20% in some cases and can lead to substantial savings. Airflow is one of the most important components of boiler control and is critical for safe, reliable, and efficient operation. Incorrect air control can result in toxic gas production, flame outs, fuel-rich conditions and explosion, inefficient operation, erratic cycling, and other issues. Boiler operators need continuous information to adjust the firing rates and distribution of fuel and air to the burners. This can sometimes be difficult to obtain particularly when the air flow is lesser than the demand. Itís common to feed excess air to the boiler at all loads to ensure complete combustion of the fuel. However, this practice can reduce efficiency. Too much air means excess fan power and stack loss from unused oxygen. Lesser air means unburnt fuels in stack. A careful balance between fuel and air is necessary for optimum efficiency, which can only be obtained through careful, multivariable measurement of airflow, fuel flow, and analytical analysis of the stack gases.
Keywords: Bipolar Air Demand, Boilers, Arduino Controller, Stack Gases.