Tailpipe emissions from gasoline direct injection (GDI) and port fuel injection (PFI) vehicles at both low and high ambient temperatures. (September 2016)

• Record Type: Journal Article
• Authors: Zhu, Rencheng; Hu, Jingnan; Bao, Xiaofeng; He, Liqiang; Lai, Yitu; Zu, Lei; Li, Yufei; Su, Sheng
• Is Part Of: Environmental pollution. Volume 216(2016)
• Page Start: 223
• Page End: 234
• Publication Date: 2016-09
• Subjects: Particulate matter -- Particle number (PN) -- Gasoline vehicle -- Gaseous emissions -- Fuel consumption; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2016.05.066
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Vehicle emissions are greatly influenced by various factors that are related to engine technology and driving conditions. Only the fuel injection method and ambient temperature are investigated in this research. Regulated gaseous and particulate matter (PM) emissions from two advanced gasoline-fueled vehicles, one with direct fuel injection (GDI) and the other with port fuel injection (PFI), are tested with conventional gasoline and ethanol-blended gasoline (E10) at both −7 °C and 30 °C. The total particle number (PN) concentrations and size distributions are monitored with an Electrical Low Pressure Impactor (ELPI + ). The solid PN concentrations are measured with a condensation particle counter (CPC) after removing volatile matters through the particle measurement program (PMP) system. The results indicate that decreasing the ambient temperature from 30 °C to −7 °C significantly increases the fuel consumption and all measured emissions except for NO x . The GDI vehicle exhibits lower fuel consumption than the PFI vehicle but emits more total hydrocarbons (THC), PM mass and solid PN emissions at 30 °C. The adaptability of GDI technology appears to be better than that of PFI technology at low ambient temperature. For example, the CO, THC and PM mass emission factors of the PFI vehicle are higher than those of the GDI vehicle and the solid PN emission factors are comparable in the cold-start tests at −7 °C. Specifically, during start-up the particulate matter emissions of the PFI are much higher than the GDI. In most cases, the geometric mean diameter (GMD) of the accumulation mode particles is 58–86 nm for both vehicles, and the GMD of the nucleation mode particles is 10–20 nm. The results suggest that the gaseous and particulate emissions from the PFI vehicle should not be neglected compared to those from the GDI vehicle especially in a cold environment. Graphical abstract: Highlights: Tailpipe emissions from PFI and GDI vehicles were tested at both −7 °C and 30 °C. Low temperature led to higher fuel consumption and most emissions, except for NO x . The test PFI emitted more PM mass than the GDI with both gasoline and E10 at −7 °C. The solid PN emission factors of PFI were comparable to those of GDI at −7 °C. High peaks of solid PN emission rates were observed during some deceleration. Abstract : GDI emits more PM mass and solid PN than PFI at 30 °C, but particulate matter emissions from PFI were comparable or even higher than those from GDI at −7 °C.