Effect of dynamic injection pressure on performance, emission and combustion characteristics of a compression ignition engine

Diesel engine emissions produced during burning of fossil fuel are extremely accountable for numerous serious problems. In order to lessen these emissions, performance of diesel engine needs to be improved. Fuel injection pressure is one of the operating parameters that affects the performance and emissions of a diesel engine which has been reported in this review paper. Decrease in injection pressure results in inferior combustion which leads to increase in BSFC and decrease in BTE. Injection pressure increase results in better mixing of air and fuel. As a result, combustion improves which leads to reduced BSFC and increased BTE. Due to superior air-fuel mixture resulting from increase in injection pressure, CO and HC emission decreases. Also, exhaust gas temperature decreases too. Increase in injection pressure results in increased heat release rate which leads increase in NO emission. Literatures reports that, increasing the injection pressure results in up to 18% and 9% reduction of BSFC and EGT. Furthermore, it is possible to achieve more than 50% CO and HC and 28% NOx emission reduction by increasing the fuel injection pressure. (C) 2015 Elsevier Ltd. All rights reserved

Influence of engine operating variable on combustion to reduce exhaust emissions using various biodiesels blend

This study focused mainly on the behavior of biodiesel operated under various operating conditions. The experiment was conducted with B20 of three potential biodiesel sources, namely, rice bran, Moringa and sesame oil. A significant outcome was observed from the test results, which showed that the brake thermal efficiency of the biodiesel blend was about 3.4% lower under constant speed running conditions than constant torque operating conditions. Similarly, about 6.5% lower exhaust gas temperatures under constant speed running conditions with lower peak pressure were found than under constant torque testing conditions. On the subject of emission, it is seen that the testing conditions also have an influence on exhaust emission. For instance, under constant speed running conditions, the engine produces about 19.5% lower NO and 19% higher HC than under constant torque running conditions. A similar influence was also found in the pressure and heat release rate. However, there is a clear variation found in the results under different operating conditions. Therefore, it is necessary to test the fuel under various operating conditions, such as constant torque, constant speed, variable injection timing, for the optimal use of biodiesel

Effect of idling on fuel consumption and emissions of a diesel engine fueled by Jatropha biodiesel blends

An engine running at low load and low rated speed is said to be subject to high idling conditions, a mode which represents one of the major problems currently the transport industry is facing. During this time, the engine can not work at peak operating temperature. This leads to incomplete combustion and emissions level increase due to having fuel residues in the exhaust. Also, idling results in increase in fuel consumption. The purpose of this study is to evaluate fuel consumption and emissions parameters under high idling conditions when diesel blended with Jatropha curcas biodiesel is used to operate a diesel engine. Although biodiesel diesel blends decrease carbon monoxide and hydrocarbon emissions, they increase nitrogen oxides emissions in high idling modes. Compared to pure diesel fuel, fuel consumption also increases under all high idling conditions for biodiesel -diesel blends, with a further increase occurring as blend percentage rises

Evaluation of combustion, performance, and emissions of optimum palm-coconut blend in turbocharged and non-turbocharged conditions of a diesel engine

Fossil fuel depletion, global warming with rapid changes in climate, and increases in oil prices have motivated scientists to search for alternative fuel. Biodiesel can be an effective solution despite some limitations, such as poor fuel properties and engine performance. From this perspective, experiments were carried out to improve fuel properties and engine performance by using a binary blend of palm and coconut biodiesel at an optimized ratio. MATLAB optimization tool was used to determine this blend ratio. A new biodiesel was developed and represented by PC (optimum blend of palm and coconut biodiesel). Engine performance and emission were tested under a full load at variable speed condition by using a 20% blend of each biodiesel with petroleum diesel, and the results were compared with petroleum diesel under both turbocharged and non-turbocharged conditions. PC20 (blend of 20% PC biodiesel and 80% petroleum diesel) showed the highest engine power with lower brake-specific fuel consumption than the other tested fuels in the presence of a turbocharger. The emissions of PC20 were lower than those of all other tested fuels. The experimental analysis reveals that PC showed superior performance and emission over palm biodiesel blend

Impact of oxygenated additives to palm and jatropha biodiesel blends in the context of performance and emissions characteristics of a light-duty diesel engine

In recent years, palm and jatropha biodiesels have been considered as potential renewable energy sources in Malaysia. Therefore, this experimental investigation was conducted to improve the blend of these two biodiesels (20% biodiesel blend, named P20 and J20, respectively) with the help of oxygenated additives. The comparative improvement of P20 and J20 blends with ethanol, n-butanol, or diethyl ether as additives was evaluated in terms of performance and emissions characteristics of a four-stroke single cylinder diesel engine. The final blend consisted of 80% diesel, 15% biodiesel, and 5% additive. Tests were conducted at different speeds (1200-2400 rpm) at constant full load conditions. Use of additives significantly improved brake power and brake thermal efficiency (BTE). Compared with P20 blend, the use of diethyl ether as additive increased brake power and BTE by about 4.10% and 4.4%, respectively, at 2200 rpm. A similar improvement was observed for J20. The other two additives also improved performance. Although HC emission increased slightly, all blends with additives reduced more NO_x and CO emissions than P20 and J20 almost throughout the entire engine test. The use of ethanol as additive reduced CO emission by up to 40%, while the use of diethyl ether as additive reduced NO_x emissions by up to 13%. The additives' oxygen content, volatility, and latent evaporation heat controlled the emissions characteristics of the blends. An analysis of the combustion chamber pressure, temperature and heat release rate of the modified blends revealed interesting features of combustion mechanism, which are indicative of the performance and emissions characteristics. This experiment reveals the potential improvement of palm and jatropha biodiesel blends with the addition of three promising additives

Tailoring the key fuel properties using different alcohols (C2-C6) and their evaluation in gasoline engine

The use of ethanol as a fuel for internal combustion engines has been given much attention mostly because of its possible environmental and long-term economical advantages over fossil fuel. Higher carbon number alcohols, such as propanol, butanol, pentanol and hexanol also have the potential to use as alternatives as they have higher energy content, octane number and can displace more petroleum gasoline than that of ethanol. Therefore, this study focuses on improvement of different physicochemical properties using multiple alcohols at different ratios compared to that of the ethanol-gasoline blend (E10/E15). To optimize the properties of multiple alcohol-gasoline blends, properties of each fuel were measured. An optimization tool of Microsoft Excel "Solver" was used to find out the optimum blend. Three optimum blends with maximum heating value (MaxH), maximum research octane number (MaxR) and maximum petroleum displacement (MaxD) are selected for testing in a four cylinder gasoline engine. Tests were conducted under the wide open throttle condition with varying speeds and compared results with that of E15 (Ethanol 15% with gasoline 85%) as well as gasoline. Optimized blends have shown higher brake torque than gasoline. In the terms of BSFC (Brake specific fuel consumption), optimized blends performed better than that of E15. In-cylinder pressure started to rise earlier for all alcohol-gasoline blends than gasoline. The peak in-cylinder pressure and peak heat release rate obtained higher for alcohol gasoline blend than that of gasoline. On the other hand, the use of optimized blends reduces BSCO (Brake specific carbon monoxide) and BSHC (Brake specific hydrocarbon) emission with compared to the use of gasoline and E15. BSNOx (brake specific nitrogen oxides)emission of all alcohol-gasoline blends was higher than that of gasoline. However, MaxR, MaxD, MaxH reduces BSNOx significantly than that of E15. Thus, optimized multi alcohol-gasoline blends were found to be a better option in terms of fuel properties, engine performance, combustion and emission for an unmodified gasoline engine

Assessing effects of idling of a diesel engine operated with optimized blend of palm and mustard biodiesel

Palm is an edible feedstock which is immensely popular in Malaysia as an alternative fuel which can substitute diesel fuel. However, use of Palm biodiesel in diesel engine have a negative effect on food security, thus, in this study authors used Mustard biodiesel, which has poor fuel properties, with Palm biodiesel to produce an optimum blend. This blend will have better fuel properties compared to Mustard biodiesel and will help eliminate dependency of Palm biodiesel. To ensure that optimized blend achieves better fuel properties MATLAB optimization tool was used to find out the optimum blend ratio. Linear relationship among the fuel properties was considered for MATLAB coding. The resultant optimum blend is represented by PM. Optimum blend revealed improved fuel properties compared to mustard biodiesel. Fuel consumption and exhaust emission of diesel engine operated by the produced optimized blend blends at high idling conditions with and without a turbocharger installed, were evaluated. Optimized blend achieved lower CO, HC and NOX emission compared to Mustard biodiesel blends and also improved fuel consumption at idling conditions. When the engine was turbocharged it further decreased CO, HC and fuel consumption, but significantly increased NOX emission.</p