Porování přístrojů pro online měření částic ve výfukových plynech zážehových motorů s přímým vstřikem

Abstract

This master thesis examines the suitability of online particle monitoring instruments for measurement of particle emissions from Direct Injection Spark Ignition (DISI) engines. A typical passenger car DISI engine was operated on gasoline and its mixtures with 25% iso-butanol and 25% n-butanol on a chassis dynamometer along speed and torque points corresponding to those measured during WLTC driving cycle on a typical midsize passenger car. Multiple cold and warm starts WLTC tests were conducted. Concentrations of particles in raw exhaust were measured by two particle classifiers, Engine Exhaust Particle Sizer (EEPS), Electrostatic Low-Pressure Impactor (ELPI), and by photoacoustic analyzer (Microsoot Sensor, MSS). Mean Total Particle Number Concentration measured by EEPS and ELPI and mean Total Particle Mass Concentration measured by MSS and derived from EEPS and ELPI measurements were compared. A reasonable agreement between the instruments (Particle Number Concentrations measured by EEPS and ELPI, Particle Mass Concentration measured by ELPI and MSS) was observed on gasoline, with somewhat high differences on butanol blends. High temperature version of ELPI, sampling raw exhaust, exhibited the high Signal to Noise ratio (SNR), followed by MSS and EEPS. In general, all instruments have shown a substantial decrease in particle emissions for both isomers of butanol relative to the gasoline, with relatively small differences between the two isomers. In general, all instruments provided useful measurements.This master thesis examines the suitability of online particle monitoring instruments for measurement of particle emissions from Direct Injection Spark Ignition (DISI) engines. A typical passenger car DISI engine was operated on gasoline and its mixtures with 25% iso-butanol and 25% n-butanol on a chassis dynamometer along speed and torque points corresponding to those measured during WLTC driving cycle on a typical midsize passenger car. Multiple cold and warm starts WLTC tests were conducted. Concentrations of particles in raw exhaust were measured by two particle classifiers, Engine Exhaust Particle Sizer (EEPS), Electrostatic Low-Pressure Impactor (ELPI), and by photoacoustic analyzer (Microsoot Sensor, MSS). Mean Total Particle Number Concentration measured by EEPS and ELPI and mean Total Particle Mass Concentration measured by MSS and derived from EEPS and ELPI measurements were compared. A reasonable agreement between the instruments (Particle Number Concentrations measured by EEPS and ELPI, Particle Mass Concentration measured by ELPI and MSS) was observed on gasoline, with somewhat high differences on butanol blends. High temperature version of ELPI, sampling raw exhaust, exhibited the high Signal to Noise ratio (SNR), followed by MSS and EEPS. In general, all instruments have shown a substantial decrease in particle emissions for both isomers of butanol relative to the gasoline, with relatively small differences between the two isomers. In general, all instruments provided useful measurements.