Steam Pressure Control in Boiler

• Steam pressure is the key variable that indicates the state of balance between the supply and demand for steam.
• If supply exceeds demand, the pressure will rise.
• Conversely, if demand exceeds supply, the pressure will fall.
• Plants may experience fluctuations in demand due to batch processes or other process changes.
• In this case, a steam flow feedforward signal is used with steam pressure control.
• The term Plant Master is most applicable to the situation in which more than one boiler supplies a common steam header.
• In this case, there are multiple boiler masters but only one plant master.
• The plant master generates the master firing rate demand signal that drives the individual boilers in parallel.
• With multiple boilers, the Plant Master is typically configured with a variable gain, based on the number of boilers in automatic mode.