Control system for variable pressure once-through boilers

Patent · Tue May 19 04:00:00 EDT 1987

OSTI ID:6506657

Russell, T D; Waker, R R

A method is described of controlling a power plant assembly during low load operation. The method comprises: directing the flow of fluid exiting from a primary superheater of the power plant assembly through a flash tank, a secondary superheater, and thence through a turbine valve of a turbine. The turbine valve is opened approximately 70% of its full open position, during the low load operation; controlling the furnace pressure in a furnace of the power plant assembly at a first constant value by means of a first valve, located at the inlet of the flash tank, during the low load operation; controlling the throttle pressure at the turbine valve at a second constant value, less than the first constant value, by means of a second valve, located at the steam outlet of the flash tank, during the low load operation; and regulating the water level in the flash tank by means of a third valve, located at the water outlet of the flash tank, which allows excess water in the flash tank to be drained off to a condenser of the power plant assembly.

• Assignee: Babcock and Wilcox Co., New Orleans, LA
• Patent Number(s): US 4665706
• OSTI ID: 6506657
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
200104 -- Fossil-Fueled Power Plants-- Components
42 ENGINEERING
421000* -- Engineering-- Combustion Systems
BOILERS
CONTAINERS
CONTROL
CONTROL EQUIPMENT
CONTROL SYSTEMS
EQUIPMENT
FEEDWATER
FLOW REGULATORS
FLUID FLOW
FURNACES
HYDROGEN COMPOUNDS
INTAKE STRUCTURES
MACHINERY
MECHANICAL STRUCTURES
OXYGEN COMPOUNDS
POWER PLANTS
PRESSURE CONTROL
SUPERHEATERS
TANKS
TURBINES
TURBOMACHINERY
VALVES
WATER