ABSTRACT
In this experimental investigation, Kariba weed biodiesel (KSB) blended with n-pentane has been tested in conventional and ceramic-coated thermal barrier engines, and the results have been compiled and presented. A single-cylinder, four-stroke, direct injection diesel engine has been used as the test engine with eddy current dynamometer loading as used in the experimental setup. The tests were repeated in various ambient conditions to get an optimal value. Ceramic coating has been done with partially stabilized zirconia by the plasma arc spraying process. Among the quantum of tests conducted, 90% KSB blended with 10% n-pentane showed appreciable results when it was compared with the test fuel (neat diesel). The brake thermal efficiency and brake-specific fuel consumption were found to be better when compared with neat diesel. At increasing load, unburnt hydrocarbon, carbon monoxide, and smoke opacity emissions were appreciably reduced.
ABSTRACT
The present experiment deals with the study of the effect of addition of diethyl ether (DEE) on the performance and emission characteristics of a thermal-barrier-coated (TBC) engine run on papaw (Carica papaya) and eucalyptus oil blends. The fuels studied were test blends, CPME30Eu70 (papaw methyl ester 30% and eucalyptus oil 70%) and CPME30Eu70 + 10% DEE, and diesel. Optimum results were obtained for CPME30Eu70 with DEE in a TBC engine. The addition of DEE creates a lean mixture, and its low viscosity, high cetane number, and volatility improve the performance of biofuel-powered engines. The investigation shows that the addition of 10% DEE gives the best results in brake-specific energy consumption (BSEC), brake-specific fuel consumption (BSFC), and brake thermal efficiency (BTE). The BTE of the DEE-adapted CPME30Eu70 blend was 32.2%, whereas for diesel it was 31.8%, which was 1.2% higher than that of CPME30Eu70 at normal mode of operation. The addition of DEE to CPME30Eu70 reduced BSEC and BSFC by 8.9 and 7.2%, respectively, compared to a non-coated engine powered by CPME30Eu70. The combination of DEE and CPME30Eu70 nominally decreased nitrogen oxide emissions. The carbon monoxide and hydrocarbon emissions of CPME30Eu70 after DEE addition were 0.195% vol. and 38 ppm, respectively, which were 13.3 and 5.1% lower than those for CPME30Eu70 powered by a compression ignition engine. The experiment found that adding DEE to CPME30Eu70 could improve its atomization and spray characteristics. Moreover, the performance and emission characteristics of the CPME30Eu70-powered engine were enhanced.
ABSTRACT
The present research work was conducted on a compression ignition engine to assess the engine characteristics fueled with the blend of diesel and high-oxygenated additives such as ethanol. Ethanol does not easily blend with diesel. In order to attain a homogeneous mixture, a small amount of additive is added to the blend. Different additives were added to the blend to form a homogeneous mixture. Stability test was conducted on the blend to ensure prolonged homogeneity. The additives used for the test purpose were isopropanol, oleic acid, and ethylene acetate. From the stability results, it was found that oleic acid was the best additive which produces a better homogenous mixture for the blend of ethanol and diesel. One percentage of oleic acid is used as an additive to blend ethanol and diesel. The different combinations of blend ratios used for the test purpose were D90E10, D80E20, and D70E30. All the aforementioned blends have low cetane number because of ethanol, which was compensated by adding 1% DEE (diethyl ether) to all the blends. Experimental results exhibit that there is an improvement in the performance characteristics, such as brake thermal efficiency (BTE) and specific energy consumption (SEC), with the enrichment of DEE in ethanol-diesel blend. It is also noticed that the blend without DEE exhibited lower magnitude. This is mainly due to higher energy content and cetane number of DEE. Emission characteristics, like hydrocarbon (HC) and carbon monoxide (CO), were found to drastically increase with the increase in the ethanol concentration in the diesel blend. This is attributed to higher latent heat of vaporization (LHV) of ethanol present in the blend. Combustion pressure and heat release rate of the DEE-enriched ethanol blends were higher by 2.2 % and 2.4 %, respectively, when compared with their corresponding blends without DEE. This is a result of higher volatility of DEE which leads to better combustion. Graphical abstract.
