ANSI/ISA-77.41.01:2015

ANSI/ISA-77.41.01-2015, Fossil Fuel Power Plant – Boiler Combustion Controls, establishes minimum design and functional requirements for combustion control systems in fossil fuel power plant boilers with steaming capacities of 200,000 lb./hr. (25 kg/s) or greater. It covers key subsystems like furnace pressure (balanced draft), airflow control and fuel flow control for coal, oil, gas or combinations thereof, excluding burner control, safety systems and certain boiler types. This standard defines essential process measurements, control and logic requirements, including automatic tracking, air/fuel ratio management, cross-limiting controls and oxygen trimming. It also defines final control device fail-safe criteria, system reliability through redundancy, alarm requirements and operator interface needs. Additionally, it provides tutorial annexes on combustion principles, control strategies for different fuels, including dual-fuel and pulverized coal-fired boilers and fault tolerance considerations like geographic and functional distribution and component redundancy to maintain safe, efficient and reliable boiler operation.