Industrial Boiler Optimization Utilizing CO Control

Abstract

Escalating energy costs have caused industry to search the technical section for the current state-of-the-art in combustion and control technology for power generation. Long a forgotten area in many industrial facilities, today the steam generating complex is the focus of many corporate and plant managers.

This paper discusses the approach of a large chemical company that is effectively utilizing a direct digital control (DOC) system coupled with the measurement of carbon monoxide to optimize boiler combustion and generate steam in the most cost effective manner. Significant reductions in the amount of excess air have resulted from the use of CO as a control parameter. Previously, combustion effectiveness was determined by the more typical 02 measurement. For reasons of boiler leakage and gas stratification, this control technique was not suitable when operating close to stoichiometry. The use of DOC type control in our multiple boiler installation has also enabled the intelligent allocation of boiler capacity by evaluating steam demand versus incremental boiler steam cost. The system selectively increases or decreases boiler loads within specified constraints to provide the lowest overall steam production cost while continuing to meet the steam demand.