Senior Process Engineer Steve Campbell using portable test equipment at the ESP inlet.
Even a well-maintained and modern boiler equipped with advanced controls and instrumentation can operate inefficiently if these controls are not effectively used. In addition, combustion conditions in boiler furnaces are constantly changing, so it is important to pay attention to the operational settings to ensure they result in efficient boiler operation. For these reasons, operational tuning is an important activity to regularly implement for combustion optimization.
Boiler tuning can address a variety of operational issues or concerns. For example, a paper mill in the northwest United States wanted to reduce auxiliary fossil fuel firing in its biomass-fired power boiler (PB). However, the boiler had strict carbon monoxide (CO) and nitrogen oxides (NOx) limits that were a concern at increased biomass firing rates. In order to achieve the mill’s combustion goals while maintaining emissions compliance, Jansen implemented optimization tuning. During the tuning process, Jansen directly worked with the boiler operators to adjust the combustion air and biomass fuel delivery systems of the PB. The efforts successfully improved the uniformity of the grate fuel bed at the increased biomass firing rate, lowered CO emissions by 48%, and simultaneously maintained compliance with the NOx limit. Using field-measured data to support the tuning, Jansen was also able to identify deficiencies in the fuel supply and overfire air systems of the boiler for the mill to address to further optimize the PB performance.
In addition to optimizing boiler operations, tuning can also familiarize boiler operators with the unique tools at their disposal. No two controls systems are alike, and it takes experience and a strong understanding of the energetic processes at work to efficiently operate a boiler. Working together with Jansen’s experts to tune the boiler helps operators gain the knowledge required to keep the unit running smoothly long after Jansen’s tuning activities are over. In addition, custom operator training manuals can be developed for boilers which Jansen has previously tuned. These are especially helpful for plants experiencing high operator turnover due to retirements.
Finally, tuning is also an essential part of Boiler Maximum Achievable Control Technology (MACT) Tune-ups, which are an EPA-enforced requirement for industrial boilers designated as Major Sources. Boiler MACT Tune-ups require that boilers are tuned to reduce CO emissions about once every five years for boilers operating with oxygen trim systems and annually for those operating without. While implementing these tunings, Jansen takes care to lower CO emissions while ensuring that all other aspects of combustion are optimized and stabilized.
Optimization tuning is a versatile tool to verify that your boiler’s operational settings are not limiting its performance. Whether helping plants alter their fuel firing rates, diagnosing existing combustion deficiencies, training new operators, or lowering emissions, Jansen’s combustion expertise and hands-on experience with a variety of controls systems ensure that every tuned boiler operates at its best.
Author: Morgan N. Silverman, Process Engineer