Numerical analysis of carbon monoxide, formaldehyde and unburned methanol emissions with ozone addition from a direct-injection spark-ignition methanol engine

摘要

Numerical simulations were performed to assess the relationship between carbon monoxide (CO) and formaldehyde and unburned methanol-unregulated emissions in cylinders and a tailpipe with ozone (O-3) addition from a direct-injection spark-ignition methanol engine. This simulation study was performed during cold-start and steady-state modes with O-3 addition of 3000 and 7000 ppm. The initial phase of produced CO and formaldehyde is advanced significantly with O-3 addition, but the initial phase of produced unburned methanol had little impact. The effects of O-3 addition on the formation and oxidation of CO, formaldehyde and unburned methanol are lower for the steady-state compared with the cold-start mode. The effects of O-3 addition on CO, formaldehyde and unburned methanol production and consumption in the cylinder are formaldehyde CO unburned methanol. CO, formaldehyde and unburned methanol emissions decrease with increasing O-3 addition. When the exhaust valve opened, CO, formaldehyde and unburned methanol emissions with 7000 pprn O-3 addition for the cold-start mode are 153%, 52% and 70% lower than those without O-3 addition, respectively. CO, formaldehyde and unburned methanol emissions with 7000 ppm O-3 addition for the steady-state mode are 52.6%, 28% and 28% lower firan those without O-3 addition, respectively. (C) 2017 Elsevier Ltd. All rights reserved.