Understanding the role of nanoparticle size on energy, exergy, thermoeconomic, exergoeconomic, and sustainability analyses of an IC engine: A thermodynamic approach

Abstract

This paper aims to thermodynamically and economically discuss the role of nanoparticle size on a CI engine performance. Accordingly, three different sizes (28, 45, and 200 nm) of titanium oxide nanoparticles are added into the canola oil methyl ester-diesel blends (C10) at the same mass fractions of 100 ppm. The experiments were conducted on a single-cylinder, air-cooled diesel engine. During the experiments, the engine speed was constant at 1800 rpm, and the engine was loaded from 2.5 and 10 Nm with gaps of 2.5 Nm. It is seen that the viscosity, heating value, and cetane number of the resultant test fuels dropped as the particle size gets smaller. In the results, brake-specific fuel consumption (BSFC) initially increased by 5.5% with the biodiesel added into diesel fuel. However, the addition of nanoparticles noteworthy dropped the BSFC value by roundly 16.91% for C10 + 28 nm TiO2, 12.97% for C10 + 45 nm TiO2, and 10.24% for C10 + 200 nm TiO2. As the engine load increases, BSFC dropped and energy as well as exergy efficiencies for each test fuel improved. The efficiency of the first and second laws at 12 Nm is found to be 25.97% and 24.37% for DF, 25.36% and 23.77% for C10, 27.60% and 25.88% for C10 + 28 nm TiO2, 27.03% and 25.34% for C10 + 45 nm TiO2, 26.65% and 24.99% for C10 + 200 nm TiO2, respectively. Collectively, average energy efficiencies of test fuels are 6.65% bigger than exergy efficiencies. On the other hand, it is noticed that the energy loss rate, energy rate, exergy rate, exergy loss rate, exergy destruction rate, and thermoeconomic metrics are increasing with any increment in engine load for each test fuel. The lowest values of energy and exergy efficiency benchmarks are found for C10 test fuel, while the highest ones are detected for C10 + 28 nm TiO2 test fuel. The addition of nanoparticles considerably increases the unit cost and specific exergy cost of test fuels. Despite their high unit costs, the most suitable fuels in terms of both exergoeconomic, and sustainability aspects are, nevertheless, the nanoparticles-added fuels due to their high exergy efficiencies. In the conclusion, this paper declares that the particle size of nanomaterials is a very effective physical property on the IC engine performance, and the small particle sizes of the same type nanoparticles should be preferred in terms of better energy, exergy, thermoeconomic, exergoeconomic, and sustainability results.