The Emission Characteristics of a Diesel Engine During Start-Up Process at Different Altitudes

Abstract

With increasingly stringent emission regulations, the cold start emissions have become more important than ever. Using a low compression ratio is a feasible way to improve a heavy-duty engine’s efficiency and emissions. However, cold start performance restricts the development of this technology, especially at high altitudes. In response, we conducted a study of the emissions of a heavy-duty low-compression-ratio diesel engine during start-up process at different altitudes. A plateau simulation system controlled the inlet and exhaust pressure to create altitude environments of 0 m, 1000 m, 2000 m, 3000 m, 3750 m and 4500 m. The gas, particulate and volatile organic compound (VOC) emissions were analyzed with speed and cycle during the start-up process. The results indicated that cold start performance and combustion characteristics became worse as altitudes increased. The gas and particulate emissions of carbon monoxide (CO), carbon dioxide (CO2), total hydrocarbon (THC) and nitrous oxide (NOX) almost all increased as the engine speed and altitude increased, and was much higher than in idle conditions. The PN and PM emissions in each particle diameter also increased as the altitude increased, which was the same as the nucleation mode and the accumulation mode particles. VOC emissions were also measured, which increased during the start-up process as altitudes increased.

What the COVID-19 lockdown revealed about photochemistry and ozone production in Quito, Ecuador

“…Hence, we used measurements of non-methane VOCs as well as CO by Jaimes-Palomera et al (2016) in the Mexico City Metropolitan Area from March to May 2012. Mexico City, located at 2550 masl in the tropics, shares with Quito conditions of high altitude that directly influence combustion and levels of VOCs as previous work demonstrates ( Nagpure et al, 2011 ; Fang et al, 2019 ). Hence, Mexico City's measurements are the closest observational data suitable to be applied in the present case.…”

“…3 also contains average levels (before and after the lockdown) of propene, one of the ten VOCs derived from VOC/CO ratios. Previous work demonstrates the high correlation of traffic-related VOCs with CO, in particular at high altitude, where elevation plays a role at increasing VOCs emissions ( Bon et al, 2011 ; Nagpure et al, 2011 ; Fang et al, 2019 ). Hence, estimating VOCs levels with observed factors from another high elevation Latin American city is suitable for the present case.…”

The urgent need to control volatile organic compound pollution over the Qinghai-Tibet Plateau

“…For example, with increasing altitude, the particle number concentration increases significantly, and the discharged particles change into fine-grained particles. 19 , 20 , 21 , 22 What is more surprising is that different altitudes can change not only the total amount of emissions but also the chemical composition of emissions. For example, with increasing altitude, the incomplete combustion of fuel will change the emission ratio of organic carbon and elemental carbon, and the content of water-soluble ions in particulate matter will decrease.…”

Waste to energy conversion for a sustainable future

“…A well-tuned diesel engine operating at high combustion temperatures produces the least amount of CO 2 ( Gotmalm, 1992 ). The CO 2 emissions from diesel engine have been reduced by improved fuel injection technology, precise compression ratio, exhaust gas recirculation strategy, supercharging, NOx treatment, diesel oxidation, and charge movement ( Fang et al., 2019 ; Fiebig et al., 2014 ).…”