碳烟中体积分数,初级粒径检测方案(烟气分析仪)

Application of Auto-Compensating Laser-Induced Incandescence好 (AC-LII) to Measuring Particulate Emissions GregoryJ. Smallwood Peter O. Witze William D. Bachalo National Research Council Sandia National Laboratories Artium Technologies， Inc. Auto-Compensating LII (AC-LII) etwo-color pyrometry to determine theparticle temperaturepermits use of low-fluence AC-LII Features 一particles are kept below the sublimationtemperatureo this new technique automaticallyucompensates for any changes in theexperimental conditions- fluctuations in local ambient temperaturevariation in laser fluencelaser beam attenuation by the particulatematterdesorption of condensed volatile material e in situ and nonintrusiveesignal is proportional to soot volumefraction·spatially resoivedo time resolvedelarge measurement rangeie- not limited by aggregate size·high precision and repeatabilityehigh speed data acquisition and analysisAC-LII Benefitsedilution of sample not requiredestable measurement of elemental carboninsensitive to presence of other speciesecan operate at very low concentrationsereal-time resultsecycle-resolved measurements possible*can provide particulate morphology (size size distribution， number density) when combined with scattering Artium Technologies LII Instrument 1qouantitative measurement of soot：-concentration · 1 ppt-10 ppm· measurement range>1，000，000：1primary particle diameter· typically 5-50 nmaactive surtace area·50-200m/g- number density of primary particlesabsolute intensity (patented)-NIST-traceable calibration procedurereal-time two-colour pyrometry(patented)- particle temperaturelaser beam profile (patent pending)nP- uniform heatinglow laser fluence (patent pending)- no sublimation Light Duty Diesel： Free-Acceleration Accelerator position snapped from 0% to28%；no load Ensembleaveraged free acceleration me8： 片WY ps On-Road LII Measurements ofSoot Frecway acceleration to 67mph wwiwww Timeseconds Pedal-to-the-metal Summary eworks well for on-road measurements -rugged，reliable， repeatable eset-up and running in ~2hours eeconomical -unattended operation eonly unanticipated problem was heat due to electrical generator Sunnyvale， CA， USA Peak Power 74.6 KW (@ 180D rpm) Heavy Duty Diesel： Steady-State AVL Soot Concentration {mgim3) LIl Soot Concentration {pppbj LII and AVL Smoke Meter correlate well NO， vs. LII Soot Tradeoff over a wide range of engine conditions more than two orders of magnitude eLII used to rapidly measure soot variation in concentration concentrations over wide range of EGR rates at 8 modes evidence suggests that SOF plays a role， particularly at mode 1 permits rapidengine optimization Diesel SUV： Chassis Dynamometer Detail Summary ● AC-LII -provides an independently-calibrated technique based on sound physics to determine the volume fraction of elemental carbon in particulate emissions -is immune to interference from other species， such as volatiles the instrument based upon AC-LII -correlates well with other techniques， including dry gravimetric measurements -provides excellent sensitivity (<0.2 mg/mi) -has unprecedented temporal response， reliably following transients - has a wide measurement range - is applicable to both raw and diluted exhaust - is rugged enough for on-board measurements - continuous， unattended operation is a powerful feature