Comparison of natural gas and propane addition to combustion air in terms of engine performance in compression ignition engine

This study aims to examine and compare the effects of natural gas and propane addition to the combustion air of diesel engines on engine performance. Engine tests were carried out at four different loads, 25%, 50%, 75%, and 100%, at 1500 rpm and 2000 rpm. Natural gas and propane have been added separately to the combustion air and sent to the cylinders at 250 g/h and 500 g/h mass flow rates. The results obtained through measurements and calculations (cylinder pressure and temperature, fuel consumption and emissions) have been presented in detail. When the experimental results were examined, maximum pressure of approximately 59 bar was obtained using 500 g/h natural gas at 50% load and 1500 rpm. In terms of BSFC, the best results were obtained at 1500 rpm and full load, and by adding 250 g/h and 500 g/h natural gas to the combustion air, 20% and 21% reduction in BSFC was achieved, respectively, as compared to diesel fuel combusted alone. In the same conditions, by adding 250 g/h propane to the combustion air, approximately 15% reduction was achieved compared to diesel fuel. With the addition of 500 g/h propane at 1500 rpm and 25% load, a 57% reduction in NOx emission was achieved. A 56% reduction in NOx emission was observed with the addition of 500 g/h propane at the same load condition and 2000 rpm

The effects of hydrogen enriched natural gas under different engine loads in a diesel engine

Natural gas, which is among the alternative fuels, has become widespread in the transportation as it is both economical and environmentally friendly. While the use of natural gas is at a significant level in spark ignition engines, it has not yet been implemented in compression ignition engines (CI) as it worsens combustion due to ignition delay. In CI engines, however, the combustion properties of natural gas (NG) can be improved by adding hydrogen (H-2) to NG. This is one of the methods applied to use natural gas in CI engines. In this experimental study, two different volumetric rates of NG and NG/H2 mixtures were added to the combustion air in a CI engine, and engine performance and emissions were examined under different engine loads. The experiments were performed at two different engine speeds, four different engine loads and no-load condition. An engine cylinder pressure of 59.16 bar, which is the closest value to the 59.39 bar obtained in the use of diesel fuel, was obtained at 1500 rpm for "Diesel + NG(500 g/h) " and 59.9 bar (highest values) was obtained for "Diesel + (500 g/h) [80%NG+20%H2] " at 1750 rpm. For "Diesel + NG(250 g/h) " (Mix1) and "Diesel + NG(500 g/h) " (Mix2), as the engine speed increases, at the point where the maximum in-cylinder pressure is obtained occurs further to the right from top dead center (TDC). With the addition of 500 g/h NG, an increase of 4.5% was achieved in the cylinder pressure at full load, while an increase of 6.5% was achieved in the case of using "Diesel + (500 g/h) [80%NG+20%H2] ". Although the effect of the NG and NG/H2 mixtures on in-cylinder pressure was small, the fuel consumption and thermal efficiency improved. Substantial improvements in hydrocarbon (HC) emissions were observed with the use of "Diesel + (250 g/h)[80%NG+20%H2] ". Carbon dioxide (CO2) emissions decreased with speed increase, but no significant differences in terms of CO2 emissions were observed between the mixtures. There was a maximum difference of 15% between the diesel and the mixtures in CO2 emissions. Although there was a decrease in nitrogen oxide (NOx) levels with the increase in engine speed, the lowest NOx emissions of 447.6 ppmvol was observed in "Diesel thorn NG(250 g/h) " (Mix1) at 1750 rpm at maximum load. (C)& nbsp;2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved

Experimental Investigation of the Effect of Propane Addition on Diesel Engine Performance

Propane gas could be used adding to the combustion air in diesel engines to improve engine performance and reduce emissions. In the experimental study, the propane effect has been investigated in terms of the engine performance. The experiments were conducted on a four-stroke, 3-cylinder direct injection diesel engine, at constant engine speed, different fuel mixture ratios and engine torques. In the diesel engine, propane was added to the combustion air in the amount of 250 g/h and 500 g/h. Engine torques are considered as unloaded, 9,81 Nm, 19,62 Nm, 29,43 Nm and 39,24 Nm (maximum load), respectively. It has been observed that as the propane addition increases with increasing load, the pressure inside the cylinder increases, there is a gradual decrease in the exhaust gas temperature. Increasing the addition of propane for the same torque caused raise in BSFC significantly. Therefore, the addition of propane affected fuel consumption negatively. Increasing the torque has also increased the efficiency.However, considering the same torque value, the increase in the propane ratio in the fuel mixture decreasedthe efficiency.</p

Evaluation of hybrid nanoparticles to oxygenated fuel with ethanol and n- butanol on combustion behavior

The internal combustion engine type is widely used in diesel engines due to its energy efficiency. However, the use of conventional diesel has negative effects on human health and the environment. In an effort to find a more sustainable fuel option with less harmful emissions, the focus has shifted towards investigating the effects of hybrid nano additives, which are a combination of nonmetallic (graphene nanoplate) and metal oxide (TiO2), on conventional diesel (D) and oxygenated fuels (OF). The engine test was conducted at 4 different loading cases with increments of 25% from 25% to 100% at a constant speed of 1500 rpm. The results showed that the modified fuels had superior combustion behaviors, such as peak in-cylinder pressure, combustion duration, and ignition delay, compared to conventional diesel and oxygenated fuels. The peak pressures in the cylinder of modified diesel (Dm) and modified oxygenated fuel (OFm) under full load increased by 2% and 2.9%, respectively, compared to conventional diesel (D). Additionally, the brake thermal efficiencies (BTEs) of Dm and OFm were found to be 5.5% and 3% higher than D under the same test conditions. In terms of emission analysis, the modified fuels demonstrated superiority over the conventional diesel and oxygenated fuels. During full load conditions, the CO, UHC, and NO emissions of OFm compared to D dropped by 49.1%, 54.2%, and 4%, respectively. The study results indicate that the use of a hybrid fuel additive consisting of nonmetallic (graphene nanoplate) and metal oxide (TiO2) can significantly reduce harmful emissions and improve engine performance

A study on the effects of nanoparticle addition to a diesel engine operating in dual fuel mode

In this study, a diesel engine was operated both in dual fuel mode and with nanoparticle additives. The aim is to experimentally investigate the effect of both carbon nanotube additives and the addition of hydrogen/natural gas mixture to the combustion air in a compression ignition engine. 100%NG, 10%H2 + 90%NG, and 20%H2 + 80% NG gas mixtures were added to the diesel with and without CNT additives at a mass flow rate of 250 g/h using combustion air. 50 ppm nanoparticles were added to one liter of liquid fuel and mixed with an ultrasonic mixer to form a diesel fuel-CNT mixture. Engine tests were carried out at constant speed and four different engine loads and no-load conditions. Under all load conditions, in-cylinder pressure, brake specific fuel consumption, brake thermal efficiency, and exhaust emissions were investigated. Based on the experimental results, the combustion of CNT-added diesel fuel with gaseous fuels has made significant contributions to the basic engine performance parameters. The diesel with CNT additive reached a cylinder pressure of approximately 64 bar, while the D@50ppm + NG@90%+H2@10% mixture provided a 2% increase in in-cylinder pressure compared to diesel fuel. The D@50ppm + NG@90%+H2@10% also offered the highest value among all fuel alternatives with a brake thermal efficiency of 39% at full load, resulting in 9% more efficient than diesel fuel. Gas mixtures with CNT additives effectively reduced CO and HC emissions compared to other mixtures except for diesel and D@50ppm