Abstract
Boiler is a steam generating device that is used to generate electricity and provide heat in process industry and buildings. The generation of steam is carried out by harnessing thermal energy generated via combustion process. The key challenges that are posed in this process are harmful nitric oxide emissions and the energy losses from the total energy contained in the fuel. It is highly required to reduce these losses to improve boiler efficiency; however, when the operational parameters are adjusted to maximize boiler efficiency, the nitric oxide formation is adversely affected, that is, nitric oxide formation also goes up. Moreover, a little change in demand of steam may cause disturbance in all the dynamics of boiler which may go unstable if not controlled properly. All these issues necessitate measures to be taken to optimize boiler efficiency and nitric oxide as well as to regulate operational parameters like drum pressure and drum level all at the same time. In this work, a detailed study has been carried out to investigate how thermal nitric oxide emissions, combustion process and dynamics of boiler interact with each other. In this respect, dynamic models of nitric oxides, efficiency and other operational variables of boiler have been investigated, and these models have been combined to form a joint model of whole boiler system. This model is then utilized to form an efficient control of boiler variables along with trade-off-based optimization between efficiency and thermal nitric oxide emission. The results have been formed using an experimental input data from a typical package boiler to ensure the practicability of the proposed technique.