ANSI/ISA-77.44.0:2007(R2013)

ANSI/ISA-77.44.01-2007 (R2013), Fossil Fuel Power Plant – Steam Temperature Controls, sets out the basic design requirements for controlling steam temperature in fossil fuel power plant boilers with capacities of 200,000 lbs/hr or more, covering both drum-type and once-through boilers. It explains how to properly install temperature sensors and thermocouples, where to take key measurements and describes different control methods like single-stage and multi-stage attemperation. This standard explains how to manage superheat and reheat steam temperatures using tools such as spray water attemperators, fuel nozzle tilts, flue gas dampers and flue gas recirculation. It emphasizes the use of advanced control strategies like cascade and feedforward loops to respond quickly to changes and maintain stable temperatures, while also including safety features like saturation protection to prevent water damage.Additionally, it outlines what information operators need and the alarms that should be in place. The annexes provide useful background on steam temperature control concepts and typical boiler configurations, complete with diagrams. Overall, this standard offers practical guidance to help maintain that steam temperature control systems are designed and operated safely and effectively in line with modern industry practices.