Effect of Start of Injection on the Particulate Emission from Methanol Fuelled HCCI Engine

Abstract

New combustion concepts developed in internal combustion engines such as homogeneous charge compression ignition (HCCI) have attracted serious attention due to the possibilities to simultaneously achieve higher efficiency and lower emissions, which will impact the environment positively. The HCCI combustion concept has potential of ultra-low NO X and particulate matter (PM) emission in comparison to a conventional gasoline or a diesel engine. Environmental Legislation Agencies are becoming increasingly concerned with particulate emissions from engines because the health and environmental effects of particulates emitted are now known and can be measured by sophisticated instruments. Particulate emissions from HCCI engines have been usually considered negligible, and the measurement of mass emission of PM from HCCI combustion systems shows their negligible contribution to PM mass. However some recent studies suggest that PM emissions from HCCI engines cannot be neglected. In this paper, effect of start of injection (SOI) of fuel on particulate emission of a HCCI engine fuelled with methanol is experimentally investigated. In this study, port fuel injection technique is used for preparing homogeneous mixture of methanol and air. The experiment is conducted with varying SOI timings for different amount of fuel, and intake air temperature. The engine exhaust particle sizer (EEPS) is used for size, surface area and volume distributions of soot particles emitted under each of these different operating conditions. It was found that total concentration of particles increase with increasing intake air temperature and particles are mainly in the size range from 10 to 150 nm. It was found that number and size distribution of HCCI generated soot particles depends on SOI, amount of fuel injected and the intake air temperature.

Experimental Investigations of Particulate Size and Number Distribution in an Ethanol and Methanol Fueled HCCI Engine

“…Experimental setup is described in detail in a previous research paper [7]. Experimental setup is described in detail in a previous research paper [7].…”

“…HCCI engines are inherently fuel-flexible and can be operated using low-or high-grade fuels, given that the fuel-air mixture can be heated up to auto-ignition temperature of the fuel in the combus tion chamber [4], In particular, HCCI engines can be operated on primary alcohols such as ethanol and methanol [5][6][7], Alcohols are attractive alternatives to gasoline/diesel, and they are identified as fuels having potential to improve urban air quality due to their cleaner combustion characteristics [8]. Alcohols, mainly ethanol and to a lesser extent methanol, are considered as alternative fuels for in ternal combustion engines [9][10][11], Ethanol is a biomass-derived renewable fuel, which can be produced by fermentation of sugars from organic biomass materials [12]; however, methanol is mainly produced from coal-or petrol-based fuels and natural gas.…”

“…Findings of numerous medical investigations indicate that several health effects are associated with ultrafine particles having diameters below 100 nm, which are typically emitted during the combustion of fossil fuels. Parameters such as the air/fuel ratio, fuel injection timing, and engine load can increase PM emissions by as much as three orders of magnitude as compared to those for a stoichiometric operation in gasoline engines [20][21][22], In HCCI engine, PM or smoke emissions are frequently reported as "near zero" or "ultralow" [24], However, recent stud ies revealed that although the total PM mass is indeed low, signifi cant numbers of these particles remain in the size range below lOOnm mobility diameter [25][26][27][28][29][30], The study conducted for inves tigation of port fuel injection timing on methanol fueled HCCI combustion showed that particle number emissions are dependent on fuel injection timings and found that start of injection during closed intake valve condition have lower peak concentration of particles [7]. Therefore, measurement and control of engine PM emissions is absolutely necessary.…”

Impacts on Nox Emission Control Measures to Achieve EURO VI Limits - A Review

“…Fuel vaporizing type PM. Fuel vaporizing type concept is used to make the diesel vaporize quickly in compressed air [26]. For of all before experimenting Liu et al developed models to study the degree of sophistication attained for predicting problems.…”

Particulate Morphology and Toxicity of an Alcohol Fuelled HCCI Engine

“…Although most researches proved that HCCI engines produce lower PM, however considering the large number of fine particles emitted, the particulate emissions from the HCCI engine cannot be neglected [16][17]. PM can be collected by filtering the engine exhaust.…”