Lehigh Boiler OP™

Lehigh Boiler OP™ Intelligent Combustion Optimization and Control

pi_lehigh_boiler_opNew MATS Requirements
The Work Practice Standards for Organic HAP Emissions of the EPA’s MATS rule allows the use of automated boiler optimization tools such as artificial neural network software for compliance with the firing system tuning and combustion optimization part of the standard. Steam generators that install artificial intelligence-based software can delay tuning until 2016 and decrease the frequency of the tuning cycle to every four years, while achieving optimized operation of the boilers in terms of NOx and CO emissions.

Boiler OP™ for MATS
Boiler OP™ is an intelligent software package developed for combustion optimization and control. Boiler OP™ is based on the Lehigh University Energy Research Center’s (ERC) combustion optimization approach, and it combines an expert system (general deduction methods), neural networks (that mimic the behavior of the human brain) and multi-objective optimization algorithms into a single program. The ERC’s combustion optimization process considers the critical process variables affecting the combustion process and the process controlled parameters such as NOx and CO emissions, fly ash unburned carbon, unit heat rate, etc., and creates a dynamic model of the boiler operation over its operating range. Boiler OP™ requires on-line communication with the boiler DAS or DCS, identifies the best combinations of boiler control settings for optimal combustion and assist plant engineers and operators in fine-tuning boiler operations over the long term.

The ERC’s combustion optimization approach and Boiler OP™ have been used to optimize more than 30 tangentially- and wall-fired utility boilers, ranging in size from 80 to 750 MW that fire Eastern and Western fuels, including PRB, fuel blends, co-firing with fuel oil, natural gas and coke oven gas. Using control logic that was developed from results obtained by analyzing Boiler OP™ test data, the software uses relationships between emissions, unit heat rate, operational constrains and actual boiler control settings to provide real-time biases for manipulation of boiler control curves.

Key Features of Boiler OP™
•  Reduces NOx and CO Emissions
•  Reduces Fly Ash Loss on Ignition (LOI)
•  Improves Boiler Efficiency
•  Improves Net Unit Heat Rate
•  Can Provide Constrained Operation to Control Boiler Slagging
•  Can Adapt to Changes in Fuel Quality
•  Works on Closed-Loop or an Advisory Mode

Benefits
Boiler OP™ provides an option to satisfy the MATS requirements for NOx emissions reduction and better CO control. In addition to the MATS compliance focus on those emissions, Boiler OP™ has also been demonstrated to improve unit performance, reduce slagging and minimize mercury emissions from coal-fired utility boilers. The achieved results include:
1.  NOx emissions reduction from 5 to 35 percent
2.  Performance improvement from 50 to 120 Btu/kWh
3.  Mercury emission reduction from 30 to 80 percent
The actual value of these performance, emissions and O&M benefits are highly site-specific and depend on factors such as unit size, operating conditions, fuel type and cost, cost of NOx emission credits; these factors need to be evaluated for each individual unit.