DOUBLE-PATH ONCE-THROUGH BOILER SUPPLY SYSTEM Russian patent published in 1999 - IPC

FIELD: thermal engineering. SUBSTANCE: first-stage feedwater pumps are installed upstream of high-pressure regenerative heaters and second-stage ones mounted on each path of supply line, downstream of these heaters; each second-stage feedwater pump is mounted on path downstream of mixing section, and bridge incorporating high-speed shut-off element is inserted between paths downstream of second-stage feedwater pump along water flow. When in operation, shut-off element is closed, feedwater control valves are held fully open, and water flow through paths is controlled by actuator of second-stage feedwater pump; in case of emergency shut-off of one of second-stage feedwater pumps, bridge shut-off element opens and water flow through paths is controlled by means of feedwater control valves. Throttling losses in controlling feedwater flow through paths while feedwater pumps are running is eliminated due to changing the boiler over to less cost-effective running when one of stage-two feedwater pumps is shut off in emergency situation. EFFECT: improved economic efficiency of boiler unit. 1 dwg