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The improvements made on a 2.0 litre indirect injection diesel engine to achieve 20 percent increase in power output and emissions lower than Bharat Stage II is presented. The improvements made are in four major areas, namely i) Auxiliary loss reduction, ii) combustion system redesign, iii) fuel injection equipment and iv) employment of after treatment devices EGR and Oxy-cat. For auxiliary loss reduction, a thermal clutch in cooling fan is introduced to increase the net power output of the engine. Combustion system improvements include increase in swirl chamber volume ratio, optimization of glow- plug protrusion in pre- chamber, redesign of depth of clover shape and introduction of piston scoop. A different injection rate profile along with Load Dependent Timer Travel and Speed dependent Timer Travel Hysterisis controls are provided in the injection pump for lower emissions.

This paper describes the vehicle implementation and cold start calibration of a neat methanol (M100) fuelled port injected engine equipped with plasma jet ignition and prompt exhaust gas recirculation. Test results are presented in which the influence of various factors on fuel enrichment requirements were studied with the aim of identifying strategies to reduce enrichment and lower start-up emissions. Vehicle cold starting has been demonstrated down to -30°C and studied in detail circa -20°C. Reductions in start-up CO emissions at -7°C have been achieved by means of early closed loop fuel control. Experimental results are also presented which indicate that the potential exists to reduce start-up hydrocarbon emissions at 25°C when appropriate calibration strategies are employed.

This paper describes an experimental study in which the potential for fuel economy improvements with EGR was investigated using an automotive V6 engine. Steady state engine dynamometer tests were run at 2000 rpm and 200 kPa Brake Mean Effective Pressure (BMEP). The engine was fuelled with gasoline, methanol or natural gas. Plasma jet ignition was evaluated as a means of improving EGR tolerance. EGR tolerance with methanol was found to be better than with gasoline, while natural gas showed the poorest EGR tolerance. Plasma jet ignition extended EGR limits for all three fuels. Fuel economy benefits were realized with natural gas and gasoline at low EGR rates and without EGR but plasma jet ignition provided no improvements with methanol until over 10% EGR was used. Plasma jet ignition made stable operation possible with methanol at 40% EGR, where fuel economy improvements were ultimately limited by the slow burning associated with the high EGR rate.

This paper presents the results of an experimental and analytical study of the relative flammability hazard presented by the fuel tank headspace vapours of alcohol/gasoline blends. The aim was to determine if these blends pose a greater hazard in practice than conventional gasoline fuels. Three types of experiments were conducted. The first was a flammability test performed at high and low energy levels using the Bruceton method to assign a statistical probability of ignition at different temperatures. Vapour pressure measurement and gas chromatographic analysis allowed the experimental vapour phase flammability to be determined and a mathematical model to be validated. The model was used to examine the hazard parametrically for other conditions. Even with a high alcohol content, the characteristics of the vapour are strongly influenced by the more volatile gasoline fractions.

The temperature and pressure of the charge, reached at the end of the compression stroke when an engine is cranked for starting, decide whether it will start and attain selfsustained running. These, in turn, are affected by the crevice volume in, and the blowby from, the engine, particularly at cold ambient temperatures and low cranking speeds. This paper presents a model to estimate these effects. Tentative values are proposed for the parameters that appear in the model based on experiments performed on small engines motored in a cold chamber. The model can be incorporated in engine cycle simulation programs to allow for crevice and blowby effects. It is impossible to prevent gas leakage entirely from an operating reciprocating engine. Gas may leak at the valves, the cylinder head gasket, the spark plug gasket, the injector gasket and the piston rings. The gas that leaks from the cylinder past the piston rings into the crankcase is termed “blowby”.

This paper presents the methodology and results of vapour pressure measurements and vapour phase composition determinations of M20, M50, M70 and M85 methanol-gasoline blends. These blends were chosen to span the range of composition which could be found in a variable fuel vehicle tank. Vapour pressures were measured at seven temperatures from -40°C to 40°C and at vapour liquid ratios of 4:1 and 500:1. The vapour phase composition was determined for these two vapour liquid ratios at temperatures of -28.9°C (-20°F) and -17.8°C (0°F). This paper also compares the theoretical predictions of vapour pressure and fuel/air equivalence ratio of the Royal Military College multicomponent fuel volatility model to the experimental measurements.

This study describes the design and proof-of-concept testing of a system which has enabled sub-zero cold starting of a port-injected V6 engine fuelled with M100. At -30°C, the engine could reach running speed about 5s after the beginning of cranking. At a given temperature, starts were achieved using a fraction of the mixture enrichment normally required for the more volatile M85 fuels. During cold start cranking, firing is achieved using a high energy plasma jet ignition system. The achievement of stable idling following first fire is made possible through the use of an Exhaust Charged Cycle (ECC) camshaft design. The ECC camshaft promptly recirculates hot exhaust products, unburnt methanol and partial combustion products back into the cylinder to enhance combustion. The combined plasma jet/ECC system demonstrated exceptionally good combustion stability during fast idle following sub-zero cold starts.

A slightly modified thermodynamic cycle for a spark ignition engine is proposed as a means of improving cold starting, warm-up driveability and fuel economy. Tests were conducted on a single cylinder research engine using a modified camshaft to implement the cycle. Substantial improvements in BSFC were obtained not only during the warm-up period but also at normal steady-state temperatures. NOx, CO and UBHC were simultaneously reduced as well.

Engine cold starting tests have been conducted in a laboratory cold chamber to compare the performance of three 10% methanol/90% gasoline blends with that of Indolene. The blends had different Reid Vapour Pressures and tests were conducted over a wide range of fuel/air ratios at temperatures as low as −45°C. It was found that all M10 blends tested had poorer starting performance than Indolene at cold temperatures, including those of nominally higher volatility. Cold starting did not correlate to Reid Vapour Pressure even when comparing two oxygenated fuels. Graphs are presented showing minimum cold starting temperature as a function of fuel-air equivalence ratio.