Analysis of Energy of Diesel Engine using Diesel and Biodiesel Fuel Mixtures Containing Graphene Oxide Nanoparticles

Biodiesel is an eco-friendly renewable alternate fuel and is made from transesterification of vegetable oils and animal fat. The use of biodiesel fuel as a strategy to conserve energy and reduce emissions is becoming increasingly important in engines. Biodiesel fuels increase NOx emissions in the engines. Compensate for the negative effect, the use of particles additive can be a reliable solution. In this study, the state of heat balance in a single-cylinder, four-stroke diesel engine with different fuel combinations with DXBYGZ formula (X % diesel fuel, Y % biodiesel mass, and Z ppm graphene oxide nanoparticles), has been studied experimentally.

Graphene nanoparticles in three levels of 30, 60, and 90 ppm were mixed with biodiesel produced from cooking waste oil by transesterification method with volume percentages of 5 and 20% and pure diesel was used. The test engine was a diesel engine, single-cylinder, four-stroke, compression ignition, and water cooling, in the laboratory of renewable energies of agricultural faculty, Moghadas Ardabili University. The engine is connected to a dynamometer and data were obtained after reaching steady state conditions. In thermal balance study, the combustion process merely as a process intended to free up energy fuel, and the first law of thermodynamics is used. The energy contained in the fuel is converted to useful and losses energies by combustion. Useful energy measured by dynamometer as brake power and losses energy including exhaust emission and cooling system losses. Variance analysis of all engine energy balance was done by split-plot design based on a completely randomized design and the means were compared with each other using the Duncan test at 5% probability.

The results showed that by adding 60 ppm of graphene oxide and 20% biodiesel to diesel fuel, the useful output power is reduced to a minimum and is reduced by about 5.52%. The results of the model evaluation of useful power, exhaust emissions, and thermal losses in the cooling system showed that the exponential model had a better fit. By adding biodiesel and graphene oxide nanoparticles to diesel fuel, the useful power was reduced. In order to achieve the maximum useful output power and with the priority of adding biodiesel to a high amount, the fuel composition of D80B20G90 had relatively better conditions. By adding 30 ppm of graphene to pure diesel fuel, the equivalent power of exhaust fumes was reduced to a minimum of about 18.5%. In general, heat loss through the cooling system in pure diesel fuel (D100) was lower than other fuel compounds. Pure diesel fuel was recognized as the best fuel mixture due to having the highest useful power, and lowest energy losses in the form of exhaust fumes and through cooling.

By adding graphene oxide to pure diesel fuel, the useful output power was reduced to a minimum. With the increase of biodiesel to diesel fuel, the amount of power of the cooling system also increased. By adding graphene oxide to pure diesel fuel, the equivalent power of the exhaust fumes was reduced. Heat loss through the cooling system increased with the increase of nano-graphene and biodiesel.