Method for calibrating mass flowmeter in constant capacity sampling (CVS) exhaust gas analysis system

摘要

Exhaust gas sourceMixing pipe (14) andA dilute air conduit (12) and a dilute air are transportedA first mass flow meter (36) of a mixing conduit (14) through which the exhaust gas air mixture flows;A second mass flow meter (42) to calibrate the diluted air conduit (12) andCarbon dioxide concentration (cmixco2) of the exhaust gas air mixture in the mixing pipeDuring a predetermined measurement cycleA first gas analysis apparatus (34) and continuously continuous and / or non continuous measurement through a sample bagA second gas analysis apparatus (40) that continuously measures the concentration of carbon dioxide (cexhco2) of the raw exhaust gas in an exhaust gas pipelineWithA method for calibrating a mass flowmeter in a constant capacity sampling (CVS) exhaust gas analysis system isIt is well known.In order to prevent errors due to differences in measurement errors of mass flowmeters in determining exhaust gas defects, according to the present inventionThe calibration coefficient (fkal) for the second mass flow meter (42) is determined by the first carbon dioxide mass (mmixco2) determined through the carbon dioxide concentration (cmixco2) measured by the first gas analysis instrument Mass flow rate of the measured carbon dioxide concentration (cexhco2) and two mass flowmeters (36,42) of the second gas analyzerIt is determined by comparison with the second carbon dioxide mass (mexhco2) determined depending on the dependence.