Showing 3 results for Engine Performance
Seyed Mohammad Hosseini, Rouhollah Ahmadi, Mostafa Mohebi,
Volume 17, Issue 3 (5-2017)
Abstract
Concerning the adverse environmental impacts of fossil fuel consumption, many investigations have been performed on choosing more environmentally friendly fuel alternatives and sustainable resources. In this regard, hydrogen is considered to be one of the promising alternative fuels as its combustion features are the most similar to fossil fuels and it also falls into the category of renewable and clean fuels. This article studies the simulation of hydrogen-diesel combustion in heavy duty engine at full load and speed of 1600 rpm. All engine features including speed, spray angle, spray duration and input power are held fixed in the simulation. Variable parameter is the ratio of mass or hydrogen energy to diesel. Depending on input power of diesel, hydrogen is changed from 0% (pure diesel) to 70% (i.e. 70% is supplied from the input power of hydrogen and the remaining 30% from diesel fuel). The results of simulation show that hydrogen substitution with diesel at the best state leads to reduction of pollutants such as nitric oxides, carbon dioxide, unburned hydrocarbon, soot and carbon monoxide to 8%, 14%, 54%, 14% and 70%, respectively. This substitution however causes the reduction of indicated efficiency to 2.8%. Hydrogen substitution with diesel can also postpone the combustion, and resulting to increase PRR and HRR; however, this pressure enhancement does not lead to knocking.
Rasool Esmaelnajad, Mohamad Tagi Shervani-Tabar, Moharram Jafari, Seied Esmaeel Razavi,
Volume 18, Issue 2 (4-2018)
Abstract
One of the important ways for improving performance of diesel engines is selecting of a proper and efficient fuel injection pattern. In this study six different patterns of fuel injection have been considered and performance of a diesel engine by using these patterns of fuel injection have been investigate numerically by employing AVL Fire. An annulus nozzle have been consider for the fuel injection system. It is expected that considering an annulus nozzle lead to increase of spry cone angle and proper distribution of the fuel inside the combustion chamber. Results show that employing proper and efficient patterns of fuel injection lead to increase of engine power and decrease of exhaust pollutants gases. Results also show that by employing a quasi-triangle fuel injection pattern, the diesel engine has better performance in competition with the case of using a constant fuel injection. It is found that by employing a quasi-triangle pattern of fuel injection, SFC reduces to 0.2043 kg/kJ, while the engine power increased by 27.5% and the magnitude of NO increases slightly. In the case of employing a constant-decreasing fuel injection pattern, the magnitude of SFC reduces to 0.2029kg/kJ whereas the magnitude of NO increases in comparison with the case of using constant fuel injection pattern. Numerical results show that by employing a constant-increasing pattern of fuel injection, the engine power is approximately equal to the engine’s power in the case of using a constant fuel injection pattern. But in this case the magnitude of NO reduces considerably.
Seyed Reza Mousavi, Mohammad Askari, Seyed Mohammad Reza Miri,
Volume 23, Issue 6 (5-2023)
Abstract
Fossil fuel reserves are running out and its use for energy production also affects the environment. Therefore, sustainable and clean energy sources must be produced to meet the needs. In this research, mixed fuels of methyl esters of rapeseed oil, soybean oil and palm oil were produced with diesel fuel. To achieve the advantages of palm oil biodiesel (high calorific value) and soybean and rapeseed oil biodiesel (low kinematic viscosity), different biodiesel mixtures (BS10, BS20, BR10, BR20, BP10, BP20, BRSP10 and BRSP20) were used to evaluate their effect on engine performance and greenhouse gas emissions at speeds of 1800 to 2700 rpm with a step of 300 rpm under full load conditions. The physical and chemical properties of all fuel mixtures were measured according to the ASTM D6751 standard. An air-cooled, 4-stroke, naturally aspirated single-cylinder diesel engine was used for different mixture testing. The experimental results showed that in all the combined fuels, the values of power and specific fuel consumption increase with increasing engine speed, while the torque decreases. Also, the number of pollutants increases with the increment of engine speed. Based on the results, BP20 mixture fuel can be used as an alternative in diesel engines without any engine modification.
