ISA 77.43.01

Abstract

The scope of this standard is to address the unit/plant demand development subsystem for boilers with steaming capacities of 200,000 lbs/hr (25 kg/s) or greater. This subsystem includes generation demand, boiler demand development, turbine demand development, throttle/header pressure control, and unit megawatt/steam flow control as applicable. <br>This standard will address two types of process applications: <br>a) a single boiler supplying a single turbine, typical of an electric utility power plant; and <br>b) a single boiler or multiple boilers supplying a common distribution header, typical of an industrial power plant. <br>Specifically excluded from consideration are: <br>a) dispatch control; <br>b) turbine/generator control (other than turbine demand); <br>c) feedwater controls <br>d) steam temperature controls (covered separately by ANSI/ISA-77.44.01, Fossil Fuel Power Plant &#8211; Steam Temperature Controls); <br>e) combustion controls (covered separately by ANSI/ISA-77.41.01, Fossil Fuel Power Plant Boiler Combustion Controls); <br>f) steam distribution control systems; <br>g) economic loading of boilers; and <br>h) fluidized bed boilers. <br><strong>Purpose</strong> <br>The purpose of this document is to establish the minimum requirements for the functional design specifications of unit/plant demand development for control systems for fossil-fueled power plant boilers.