Full range HDSC-DNZ drum internal constant head chamber is used for subcritical drum boiler for the first time.
On June 1, 2008, Guodian Yongfu Power Generation Co., Ltd. took advantage of the overhaul opportunity to retrofit water level measurement and protection system for the # 3 furnace drum of 300 MW unit. Two GJT2000-AY19 steam jacketed probe type water columns, one WDP-705-500-20 steam jacketed bi-color water gauge glass, three HDSC-DNZ-20 drum internal constant head chambers, and one full range drum internal constant head chamber, were installed. And this is the first time that full range drum internal constant head chamber, used in actual production.
Full range drum internal constant head chamber, was retrofitted on the basic of drum internal constant head chamber of our company and applied for national patent (patent number ZL 200520118081.1) in 2005. Comparing with drum internal constant head chamber, Full range drum internal constant head chamber increases by nearly 600mm, which exceeds measurement range of original DP type water level gauge. It can be used to monitor all range of full and short water on water level when the boiler is open or close. We skillfully provide reliable method for increasing drum water level independent measurement hole, and its reliability and accuracy obtain a good validation in theory and practice.
When the unit approaches the rated load, the deviation between the four differential pressure level gauges is less than 10mm.