Effect of Utilizing a Novel Intake Manifold Design on Smoke Emissions and Particulate Size Distributions of a Gas-to-Liquid (GTL) Diesel Engine

Abstract

Smoke emissions and particulate matter (PM) size distributions were investigated on a direct-injection (DI) single-cylinder diesel engine running on both gas-to-liquid (GTL) and diesel fuels utilizing a novel spiral-helical intake manifold design. Smoke opacity was measured at a wide range of engine loads and speeds with both fuels to examine the effect of using the new manifold on smoke emissions. In addition, total PM numbers of fine particles (PM diameter ≤ 1.0 μm) and coarse particles (˃1.0 μm) were quantified with both fuels. Moreover, high-resolution transmission electron microscopy (HRTEM) images were taken with different resolutions to observe the PM sizes produced from each fuel when using the new and normal manifolds. The results showed that using the novel manifold reduced smoke emissions for both GTL and diesel fuels with about 36% at low loads and 7% at high loads. However, using the new manifold with GTL fuel showed superior performance to reduce smoke with about 60% at low loads and 10% at high loads. For the PM size distribution, the new manifold reduced total PM emissions in general. However, significant reductions were obtained with fine PM sizes (0.3–1.0 μm) when GTL fuel was used with about 30% for constant load tests, and about 40% for constant speed tests. On the other hand, the new manifold tended to increase slightly the coarse PM sizes. The HRTEM images of the PM structure for both manifolds and fuels have confirmed the above results.

An experimental and numerical investigation of the effects of the diaphragm pressure ratio and its position on a heated shock tube performance

“…[5][6][7][8] Ignition delay time (IDT), particularly in internal combustion engines, is a vital combustion characteristic that directly affects engine efficiency and exhaust emissions. [9][10][11][12][13] This property in ICE can be defined as the time required to detect heat release once the air-fuel mixture reaches the self-ignition (autoignition) temperature and pressure or the time interval between the start of ignition (raising injector needle) and the beginning of combustion. 14 The total delay period is due to a combination of physical and chemical delays.…”

“…A variety of recent studies were conducted involved using shock tubes along with high‐density fuel/air mixtures to obtain combustion features of conventional and alternative fuels at conditions relevant to those used in internal combustion engines and gas turbine machines 5‐8 . Ignition delay time (IDT), particularly in internal combustion engines, is a vital combustion characteristic that directly affects engine efficiency and exhaust emissions 9‐13 . This property in ICE can be defined as the time required to detect heat release once the air–fuel mixture reaches the self‐ignition (autoignition) temperature and pressure or the time interval between the start of ignition (raising injector needle) and the beginning of combustion 14 .…”