美国褐煤干燥进展-？ 本文由 盖德化工论坛 转载自互联网 One-Year Operating Experience with a Prototype Fluidized Bed Coal Dryer at Coal Creek Generating Station 2007Project Goals and Schedule Project ?Goals and Objectives: ?Reduce moisture content of lignite, PRB, and other high-moisture coals. ?Use waste heat from the power plant. ?Modify existing coal handling systems. ?Increase competitive position of lignite-, PRB-, and other high moisture coal-fired power plants. ?Reduce environmental impact of lignite-, PRB-, and other high-moisture coal-fired power plants ? Project Phases and Schedule: Test Burns, Fluidized Bed Dryer Design 2002 Phase 1 Pilot Dryer 2 T/hr 2003-2004 Phase 2 Prototype Dryer 75 T/hr 2005-2007 Phase 3 Commercial Operation 900 T/hr 2008- Description of Host UnitDescription Unit Coal Creek Station: ?1,150 MW lignite-fired ?Two T-fired CE boilers ?2,520 psig @ 1,005 oF/1,006 oF ?Two single reheat GE G-2 turbines ?3 Cooling towers ?Fuel HHV = 6,200 BTU/lb ?Fuel moisture = 38 percent ?Coal fired = 900,000 lb/hr per unit Prototype Coal DryerPrototype Dryer ?Fluidized bed dryer: ?Maximum capacity 112.5 t/hr. ?Remove approx. ?of total coal moisture (TM). ?Dry lignite from 38%to 29.5%(ΔTMTarget= 8.5% Abs.) ?Improve HHV from 6,2006,200to 7,0457,045. ?Uses low-grade waste heat to evaporate a portion of the fuel moisture from the lignite feedstock. ?No other heat sources are used for coal drying. ?Fully automated operation, integrated into the plant control system. ?Six patent applications on dryer design and control filed by GRE. Prototype CDS Checkout, Start-Up, and Operation SummaryPrototype Summary ?Checkout and shakedown in December 2005. ?1stcoal on January 30th 2006. ?7-hour daily test runs ?Dryer inspection in February 2006: ?No accumulation of material in the dryer ?Drying to 29.5% ?Segregator optimization from Feb 27thto Mar 3rd2006. ?Operator training before 24/7 operation ? Performance testing in March and April 2006. ?Maximum capacity tests: May and June 2006. ?Dryer inspection in May 2006: ?No wear or damage Prototype Coal Dryer PerformancePrototype Performance ? Performance tests were conducted in spring 2006 under controlled conditions to determine: ? Prototype coal dryer (CD26) performance ?Effect of partially dried coal on boiler and unit efficiency, and stack emissions. ? Prototype coal dryer was operated conservatively to gain operating experience. ?Dryer performance during regular operation was also determined. ?Coal dryer operating parameters were higher. ? Plant operating parameters and emissions were recorded plant historian. ?Coal composition and HHV were determined from coal samples that were collected manually and by automatic coal samplers. ?More than 300,000 tons of wet lignite processed to date. Prototype Coal Dryer PerformancePrototype Performance ? Performance tests were conducted in spring 2006 under controlled conditions to determine: ? Prototype coal dryer (CD26) performance ? Effect of partially dried coal on boiler and unit efficiency, and stack emissions. ? Prototype coal dryer was operated conservatively to gain operating experience. ? Dryer performance during regular operation was also determined. ? Coal dryer operating parameters were higher. ? Plant operating parameters and emissions were recorded plant historian. ? Coal composition and HHV were determined from coal samples that were collected manually and by automatic coal samplers. U.S. Market PotentialU.Potential ?280 units fire high-moisture coals (lignite and PRB) in the U.S. ?1/3 of electric power from coal ?> 100 GWel ?Sub-bituminous and lignite coals account for 52% of U.S. coal reserves. Conclusions ?A low-temperature coal drying process employing a fluidized bed coal dryer and waste heat was developed by a team led by GRE and ERC. ?The benefits of the partially dried lignite are demonstrated at GRE’s Coal Creek Station (CCS). ?Demonstration is conducted with U.S. Department of Energy (DOE) funding under DOE Award Number: DE-CF26-04NT41763. ? Phase 1. Prototype coal drying system (CDS) employing one FBD was designed, constructed, and integrated into Unit 2 at CCS. ?The prototype CDS at CCS has been in almost continuous fully automatic operation since early 2006. ?To date processed more than 300,000 tons of wet lignite. ?Dryer inspections revealed no wear or damage to its internals. ?Feeder trips for the mill receiving dried coal were eliminated. ■The oversize material, typically responsible for the trips, screened out or discharged from the dryer with the non-fluidizablematerial Coal Dryer Performance: ?Nominal coal flow rate 75 t/hr ?Coal moisture reduction8.23% Abs (8.5% target) ?HHV improvement752 BTU/lb ?Unit Performance ?Coal flow rate reduction: ■ Prototype CDS2.0% ■Full-size CDS14% ?Mill power reduction: ■ Prototype CDS3.3% ■Full-size CDS (4 FBDs)25% ?Boiler efficiency improvement: ■ Prototype CDS0.37% Abs. ■Full-size CDS(4 FBDs)2.13% Abs. ?Net unit heat rate improvement: ■ Prototype CDS0.37% ■Full-size CDS (4 FBDs)2.87% Emissions: ?NOxreduction: ■ Prototype CDS7.5% ■Full-size CDS> 10% ?SOxreduction: ■ Prototype CDS1.9% ■Full-size CDS (4 FBDs)10 to 15% ?Hg reduction: ■ Prototype CDS0.4% ■Full-size CDS(4 FBDs)15 to 20% ?CO2reduction: ■ Prototype CDS0.4% ■Full-size CDS (4 FBDs)3.00% Significant improvement in efficiency and reduction in emissions could be achieved by: ?Retrofitting existing sub-bituminous coal-fired units with a coal drying system. ? Producing dried coal for the off-site use. ?For maximum efficiency, new sub-bituminous coal-fired supercriticaland ultra-supercriticalpower plants should be designed and built with an integrated coal drying system. Future WorkFuture Work ? Phase 2. Eight full-size coal dryers (4 per unit) will be built, installed, and tested. ?Design phase is nearing completion. ?With all coal dryers in service it will be possible to reduce the moisture of total coal feed to both units at CCS (Units 1 and 2). ?Commercial operation: November 2008 ?Controlled and uncontrolled performance tests will be conducted to determine: ?Efficiency improvement ?Emissions reduction ?Effects of burning dried coal on unit operation. [ ]查看更多0个回答 . 2人已关注
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