الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 138 |  |  |
| | | from | 138 | | |
Abstract
The good thermal efficiency, reliability, and durability of diesel engines that made it more widely used in transportation sector and a variety of industry applications. However, they suffer from higher Oxides of nitrogen (NOx) emissions and soot emissions, and excessive noise due to it has high diffusion combustion ratios and improper fuel mixing, which are challenges for its combustion process. Additionally, the energy demand is increasing, fuel supplies are depleting, and large amount of harmful emissions to human health and environment are released with the use of fossil fuels. Owing to these adverse effects of the compression ignition (CI) engines, a lot of stringent politics have been lunched on the emissions limitation that made researchers looking for developing an efficient technology that produces low exhaust emissions with high combustion efficiency, in addition to the flexibility in the utilization of fuels. The premixed charge compression ignition (PCCI) strategy, and waste cooking oil biodiesel are distinct methods for the improvement of the performance and reduction of the emissions of CI engines. The current study aims to investigate the impact of using biodiesel and PCCI strategy on engine performance, combustion, and emissions compared with the results of diesel in conventional diesel combustion (CDC) mode. The study was divided into three stages. The first stage discussed the impact of various premixed percentage of diesel vapor (15%, 20%, 25%, 30%) at constant mixing temperature of 110 ⁰C in PCCI mode. The second stage studied the impact of various premixed percentage (15%, 20%, 30%) at various temperatures (100 ⁰C, 105 ⁰C, 110 ⁰C, 115 ⁰C, 120 ⁰C) in PCCI III ABSTRACT mode. The third stage studied the impact of WCO biodiesel blends (B15D85, B30D70, B45D55, and B60D40) in both CDC and PCCI modes. The experiments were carried out on a 4-stroke, single-cylinder, air cooled, direct injection (DI) diesel engine, running at 1500 rpm, which was modified to run in PCCI mode with adding an external mixing chamber to create a homogeneous mixture. After fuel injection in the mixing chamber is heated to the point of vaporization, liquid diesel fuel vapor is mixed with some fresh air, and then the mixture is directed to the intake manifold, where it is mixed with the remaining fresh air to create an external homogenous mixture that fills the combustion chamber. For the first stage, the experiments revealed that the best results were indicated for 20% diesel vapor in PCCI mode as CO, HC, NOx, and exhaust gas temperature (EGT) reduced by 34.62%, 43.75%, 2.65% and 8.53%, respectively, and almost had the same brake thermal efficiency (BTE) compared to CDC mode fueled by diesel. While increasing premixed ratio (PR) to 25% and 30% decreased the volumetric efficiency, which leads to rich mixture and deterioration of combustion and increase CO, HC, and smoke emissions. For the second stage, the results from the PCCI technique at various premixed ratios indicated a certain decrement for HC, CO, NOx and smoke emissions, with rising in BTE. The 30% premixed ratio of the fuel vapor, inducted at 110 ⁰C in PCCI mode, gave the best results as the brake thermal efficiency was raised from 28.8% for CDC mode to 34.2% for PCCI mode at full load. Additionally, NOx emissions decreased from 615 PPM to 550 PPM, HC emission decreased to 30 PPM, CO emission decreased from IV ABSTRACT 0.09% to 0.06% and there was a decrease in smoke opacity from 38% to 19.3%. For the third stage, the results showed that increasing the proportion of biodiesel in CDC mode resulted in a decrement in BTE, CO, and HC emissions in addition to an increment in brake specific fuel consumption (BSFC), NOx emissions compared to diesel. Using PCCI mode fueled with biodiesel combined both the advantages of the two methods that showed an increment in BTE in addition to decrement in EGT, CO, HC, and NOx.