ANSI/ISA-77.43.01:2014

ANSI/ISA-77.43.01-2014, Fossil Fuel Power Plant – Unit/Plant Demand Development, establishes the minimum functional design requirements for control systems managing demand in fossil-fueled power plant boilers with steaming capacities of 200,000 lbs./hr. or greater. It covers generation demand, boiler demand, turbine demand, throttle/header pressure control and unit megawatt/steam flow control for single or multiple boiler configurations supplying steam to turbines or common headers.This standard defines key terms, outlines process measurement and control system requirements, including single- and two-element boiler follow modes, turbine follow and coordinated boiler-turbine control and specifies necessary alarms and operator interface features. It excludes feedwater, combustion, steam temperature controls, economic loading, fluidized bed boilers and dispatch control. Annexes provide operational concepts such as manual, boiler follow, turbine follow, coordinated modes, load dispatch integration, nonregenerative load indices, frequency correction and automatic responses like runbacks and rundowns.