Combustion and Emissions of a Gas-to-Liquid Diesel Engine Utilizing Optimized Spiral-Helical Intake Manifold Designs

2021 ◽  
Vol 143 (6) ◽  
Author(s):  
Yasser M. Abdellatif ◽  
Ahmad T. Saker ◽  
Aboubaker M. Elbashir ◽  
Samer F. Ahmed
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Pressure Rise ◽  
Intake Manifold ◽  
Engine Emissions ◽  
Outlet Angle ◽  
Rise Rate ◽  
Inner Diameter ◽  
Gas To Liquid ◽  
No Emissions

Abstract Two simultaneous strategies were used to reduce diesel engine emissions. Optimized manifold designs were used with gas-to-liquid (GTL) fuel and its blend with diesel fuel. Six new spiral-helical manifolds were tested, which could be divided into two groups. The first group is with the same inner diameter (2.6 cm) and outlet angle (30 deg), but the different number of spiral turns (1t, 2t, etc.). The second group is with different inner diameters. The results showed that the highest pressure and heat release were achieved by m(2.6,30,1t) with the diesel–GTL blend. In addition, the heat release rate decreases with the increase in the number of turns. The same combination also reduced the pressure rise rate (dP/dθ) by about 24% compared to the normal manifold. For the emissions, the maximum reduction in CO emissions was achieved by using m(2.6,30,3t) and GTL with about 34%. In addition, the maximum hydrocarbon (HC) reduction was achieved by m(2.1,30,3t) and GTL, which is about 99% lower than that of the normal manifold. NO emissions were reduced by about 25% when m(2.6,30,4t) and GTL are used. The total particulate matters (PM) were the lowest for m(2.6,30,1t) and normal manifold in the case of diesel. Generally, it was found that the combination of m(2.6,30,1t) with GTL and its blend gave the optimum performance and low emissions among all manifolds.

Optimized Intake Manifold Designs and Their Effects on the Operation and Emissions of a Gas-to-Liquid Diesel Engine

2020 ◽  
Author(s):  
Y. M. Abdellatif ◽  
A. T. Saker ◽  
A. M. Elbashir ◽  
S. F. Ahmed
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Diesel Fuel ◽  
Alternative Fuels ◽  
The Other ◽  
Intake Manifold ◽  
Outlet Angle ◽  
Air Mixing ◽  
Gas To Liquid ◽  
No Emissions

Abstract Two simultaneous strategies have been used in this work to reduce the diesel engine emissions. First, using novel manifold designs to generate strong turbulence and improve the fuel-air mixing inside the cylinder. The second strategy is the usage of alternative fuels, namely Gas-To-Liquid (GTL) fuel and its blends with diesel fuel. In this study, six new spiral-helical manifolds designs have been tested, which could be divided into two groups. The first group is m(2.6,30,1t), m(2.6,30,2t), m(2.6,330,3t) and m(2.6,30,4t) which contains manifolds that have the same inner diameter (2.6 cm), same outlet angle (30°), but different number of spiral turns (1t, 2t..etc). The second group is m(2.1,30,3t), m(2.6,30,3t) and m(2.9,30,3t) which contains the same parameters but different inner diameters. It should be mentioned that the outlet angle of all manifolds has been tested in previous investigations [18, 52] and 30° showed the best performance. The results of the current study showed that the highest pressure and heat release achieved by manifold m(2.6,30,1t) for the blended diesel-GTL fuel. It was observed that the heat release rate decreases with the increase in number of turns. The lowest pressure raise rate was recorded for the combination of m(2.6,30,1t) and diesel fuel. Same combination also reduced the pressure raise rate (dP/dθ) by about 24% compared to the normal manifold. The bsfc for all fuels and m(2.6,30,1t) were almost the same as the normal manifold. For the emissions, NO emissions were reduced by about 25% compared to normal manifold when m(2.6,30,4t) and GTL are used. On the other hand, the normal manifold recorded the least NO emissions for the other fuels. The manifold m(2.6,30,1t) recorded slightly higher NO emissions compared to the normal manifold for all fuels. The total particulate matters (PM) were the lowest for m (2.6,30,1t) and normal manifold in case of diesel fuel. In general, It was found that the combination of m(2.6,30,1t) with diesel fuel gave the optimum performance among all manifolds, while using m (2.6,30,4t) with GTL fuel produced low emission levels.

Combustion Characteristics of Single Cylinder Diesel Engine Fueled with Blends of Thumba Biodiesel as an Alternative Fuel

2019 ◽  
Vol 969 ◽  
pp. 451-460
Author(s):  
Manpreet Singh ◽  
Mohd Yunus Sheikh ◽  
Dharmendra Singh ◽  
P. Nageswara Rao
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Heat Release Rate ◽  
Diesel Fuel ◽  
Release Rate ◽  
Mass Fraction ◽  
Pressure Rise ◽  
Cylinder Pressure ◽  
Gas Temperature ◽  
Edible Vegetable Oil

The rapid rise in energy requirement and problem regarding atmosphere pollutions, renewable biofuels are the better alternative choice for the internal combustion engine to partially or totally replace the pollutant petroleum fuel. In the present work, thumba (Citrullus colocynthis) non-edible vegetable oil is used for the production of biodiesel and examine its possibility as diesel engine fuel. Transesterification process is used to produce biodiesel from thumba non-edible vegetable oil. Thumba biodiesel (TBD) is used to prepare five different volume concentration (blends) with neat diesel (D100), such as TBD5, TBD15, TBD25, TBD35 and TBD45 to run a single cylinder diesel engine. The diesel engine's combustion parameter such as in-cylinder pressure, rate of pressure rise, net heat release rate, cumulative heat release, mean gas temperature, and mass fraction burnt analyzed through graphs and compared all thumba biodiesel blends result with neat diesel fuel. The mass fraction burnt start earlier for thumba biodiesel blends compared to diesel fuel because of less ignition delay while peak in-cylinder pressure, maximum rate of pressure rise, maximum net heat release rate, maximum cumulative heat release, and maximum mean gas temperature has found decreased results up to 1.93%, 5.53%, 4.11%, 4.65%, and 1.73% respectively for thumba biodiesel.

Cyclic Variability in Diesel/Gasoline Dual-Fuel Combustion on a Medium-Duty Diesel Engine

2013 ◽  
Author(s):  
Jiafeng Sun ◽  
Joshua A. Bittle ◽  
Timothy J. Jacobs
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Gasoline Fraction ◽  
Fuel Spray ◽  
Intake Manifold ◽  
Dual Fuel ◽  
Injection Timing ◽  
Fuel Injector ◽  
Cyclic Variability ◽  
Diesel Operation

Most studies comparing diesel/gasoline dual-fuel operation and single-fuel diesel operation in diesel engines center on time-averaged results. It seems few studies discuss differences in cyclic variability. Motivated by this, the present study evaluates the cyclic variability of combustion in both dual-fuel and single-fuel operations of a diesel engine. Steady-state tests were done on a medium duty diesel engine with conventional direct injection timings of diesel fuel into the cylinder at one speed and three loads. In addition to single-fuel (diesel) operation, dual-fuel (gasoline and diesel) operation was studied at increasing levels of gasoline fraction. Gasoline fuel is introduced via a fuel injector at a single location prior to the intake manifold (and EGR mixing location). Crank-angle resolved data including in-cylinder pressure and heat release rate obtained for around 150 consecutive cycles are used to assess cyclic variability. The sources of cyclic variability, namely the factors causing cyclic variability or influencing its magnitude, especially those related to cylinder charge amount and mixture preparation, are analyzed. Fuel spray penetration and cyclic variability of cylinder charging, overall A/F ratio, and fuel injection timing, tend to increase cyclic variability of combustion in dual-fuel operation. On the other hand, fuel type and fuel spray droplet size tend to increase cyclic variability in single-fuel operation. The cyclic variability in dual-fuel operation in this study is more serious than that in single-fuel operation, in terms of magnitude, indicated by metrics chosen to quantify it. Most measures of cyclic variability increase consistently with increasing gasoline fraction. Variations of gasoline amount and possibly gasoline low temperature heat release cause higher combustion variation in dual-fuel operation primarily by affecting premixed burning. Statistical methods such as probability density function, autocorrelation coefficient, return map, and symbol sequence statistics methods are used to check determinism. In general, the parameters studied do not show strong determinism, which suggests other parameters must be identified to establish determinism or the system is inherently stochastic. Regardless, dominant sequences and optimal sequence lengths can be identified.

Biodiesel/butanol blends as a pure biofuel excluding fossil fuels: Effects on diesel engine combustion, performance, and emission characteristics

2020 ◽  
Vol 234 (13) ◽  
pp. 2988-3000
Author(s):  
Yongcheng Huang ◽  
Yaoting Li ◽  
Kun Luo ◽  
Jiyuan Wang
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Fossil Fuels ◽  
Pressure Rise ◽  
Emission Characteristics ◽  
Performance And Emission ◽  
Combustion Performance ◽  
Combustion Duration ◽  
Rise Rate ◽  
Ignition Characteristics

Although both biodiesel and n-butanol are excellent renewable biofuels, most of the existing research works merely use them as the additives for petroleum diesel. As the main fuel properties of biodiesel and n-butanol are complementary, the biodiesel/ n-butanol blends are promising to be a pure biomass-based substitute for diesel fuel. In this paper, the application of the biodiesel/ n-butanol blends on an agricultural diesel engine was comprehensively investigated, in terms of the combustion, performance, and emission characteristics. First, the biodiesel/ n-butanol blends with 10%, 20%, and 30% n-butanol by weight were prepared and noted as BBu10 (10 wt% n-butanol + 90 wt% biodiesel), BBu20 (20 wt% n-butanol + 80 wt% biodiesel), and BBu30 (30 wt% n-butanol + 70 wt% biodiesel). It was found that adding 30 wt% n-butanol to biodiesel can reduce the viscosity by 39.3% and increase the latent heat of vaporization by 57.3%. Then the engine test results showed that with the addition of n-butanol to biodiesel, the peak values of the cylinder pressure and temperature of the biodiesel/ n-butanol blends were slightly decreased, the peak values of the pressure rise rate and heat release rate of the blends were increased, the fuel ignition was delayed, and the combustion duration was shortened. BBu20 has the approximate ignition characteristics with diesel fuel. Both the brake thermal efficiency and the brake-specific fuel consumption of BBu30 were increased by the average percentages of 2.7% and 14.9%, while NO x, soot, and CO emissions of BBu30 were reduced by the average percentages of 17.6%, 34.1%, and 15.4%, compared to biodiesel. The above variations became more evident as the n-butanol proportion increased.

Experimental Investigation of Combustion Characteristics of a Single Cylinder Diesel Engine at Altitude

2021 ◽  
pp. 1-21
Author(s):  
Zhentao Liu ◽  
Jinlong Liu
Keyword(s):  
Diesel Engine ◽  
Combustion Process ◽  
Pressure Rise ◽  
Combustion Characteristics ◽  
Atmospheric Conditions ◽  
Single Cylinder ◽  
Combustion Duration ◽  
Rise Rate ◽  
Heavy Duty Diesel ◽  
Intake Pressure

Abstract Concern over the change of atmospheric conditions at high altitudes prompted interests in the deteriorated efficiency and emissions from heavy-duty diesel engines. This study utilized a single-cylinder, four stroke, direct injected diesel engine to experimentally investigate the altitude effects on combustion characteristics. High altitude operations were simulated via reducing the intake pressure but maintaining constant engine speed and torque. The results suggested reduced in-cylinder pressure but increased temperature as altitude rose. The combustion analysis indicated a slight longer ignition delay, raising and retarding the pressure rise rate and energy release rate in the premixed combustion process. A smaller excess air ratio contributed to combustion deterioration, reflected from a retarded end of combustion, a longer combustion duration, a reduced thermal efficiency, and an increased level of incomplete combustion. However, the phasing and combustion profile were not significantly impacted, when the altitude was elevated from sea level to 2000m, at least for the engine and conditions investigated in this study. Consequently, it is not necessary to adjust the engine ECU when operated in the U.S., considering that the mean elevations of most states are lower than 2000m.

scholarly journals Assessing the optimum combustion under constrained conditions

2018 ◽  
Vol 21 (5) ◽  
pp. 811-823 ◽  
Author(s):  
Pablo Olmeda ◽  
Jaime Martín ◽  
Ricardo Novella ◽  
Diego Blanco-Cavero
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
Heat Release ◽  
Engine Speed ◽  
Direct Injection ◽  
Pressure Rise ◽  
Maximum Pressure ◽  
Low Load ◽  
Negative Effect ◽  
Constrained Conditions

This work studies the optimum heat release law of a direct injection diesel engine under constrained conditions. For this purpose, a zero-dimensional predictive model of a diesel engine is coupled to an optimization tool used to shape the heat release law in order to optimize some outputs (maximize gross indicated efficiency and minimize NO x emissions) while keeping several restrictions (mechanical limits such as maximum peak pressure and maximum pressure rise rate). In a first step, this methodology is applied under different heat transfer scenarios without restrictions to evaluate the possible gain obtained through the thermal isolation of the combustion chamber. Results derived from this study show that heat transfer has a negative effect on gross indicated efficiency ranging from −4% of the fuel energy ( ṁfHv), at high engine speed and load, up to −8% ṁfHv, at low engine speed and load. In a second step, different mechanical limits are applied resulting in a gross indicated efficiency worsening from −1.4% ṁfHv up to −2.8% ṁfHv compared to the previous step when nominal constraints are applied. In these conditions, a temperature swing coating that covers the piston top and cylinder head is considered obtaining a maximum gross indicated efficiency improvement of +0.5% ṁfHv at low load and engine speed. Finally, NO x emissions are also included in the optimization obtaining the expected tradeoff between gross indicated efficiency and NO x. Under this optimization, cutting down the experimental emissions by 50% supposes a gross indicated efficiency penalty up to −8% ṁfHv when compared to the optimum combustion under nominal limits, while maintaining the experimental gross indicated efficiency allows to reduce the experimental emissions 30% at high load and 65% at low load and engine speed.

Simulation Research of the Effect of Compression Ratios on Combustion and Emission for Methanol/Diesel Dual Fuel Engine

2014 ◽  
Vol 709 ◽  
pp. 78-82
Author(s):  
Xu Dong Zhang ◽  
Yin Nan Yuan ◽  
Jia Yi Du
Keyword(s):  
Diesel Engine ◽  
Combustion Process ◽  
Pressure Rise ◽  
Delay Period ◽  
Dual Fuel ◽  
Ignition Timing ◽  
Simulation Research ◽  
Rise Rate ◽  
Crank Angle ◽  
Ignition Delay Period

This paper has studied the influence of the different ratio on combustion process and emissions of air premixed methanol/diesel dual fuel engine. The research was based on 4B26 diesel engine, and the 3-D numerical simulation on combustion process and emissions of the diesel engine with intake premixed methanol was carried out using AVL FIRE software. The study showed that,with the compression ratio reducing,the ignition delay period prolonged, and the ignition timing delayed, the maximum firing pressure, the peak of pressure rise rate and the maximum combustion temperature in cylinder decreased, the crank angle postponed, the NOX emission decreased and the Soot emission increased obviously.

Comparative Performance, Emission, and Combustion Characteristics of Rice-Bran Oil and Its Biodiesel in a Transportation Diesel Engine

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Avinash Kumar Agarwal ◽  
Atul Dhar
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Rice Bran ◽  
Heat Release Rate ◽  
Release Rate ◽  
Rice Bran Oil ◽  
Direct Injection ◽  
Pressure Rise ◽  
Combustion Characteristics ◽  
Comparative Performance

The methyl esters of vegetable oils known as biodiesel are becoming increasingly popular because of their low environmental impact and potential as a green alternative fuel for diesel engines. Methyl ester of rice-bran oil (RBOME) is prepared through the process of transesterification. In the present investigation, experiments have been carried out to examine the performance, emission, and combustion characteristics of a direct-injection transportation diesel engine running with diesel, 20% blend of rice-bran oil (RBO), and 20% blend of RBOME with mineral diesel. A four-stroke, four-cylinder, direct-injection transportation diesel engine (MDI 3000) was instrumented for the measurement of the engine performance, emissions, in-cylinder pressure-crank angle history, rate of pressure rise, and other important combustion parameters such as instantaneous heat release rate, cumulative heat release rate, mass fraction burned, etc. A careful analysis of the performance, emissions, combustion, and heat release parameters has been carried out. HC, CO, and smoke emissions for RBO and RBOME blends were lower than mineral diesel while NOx emissions were almost similar and brake specific fuel consumption (BSFC) was slightly higher than mineral diesel. Combustion characteristics were quite similar for the three fuels.

Low NOx and Low Smoke Operation of a Diesel Engine Using Gasolinelike Fuels

2010 ◽  
Vol 132 (9) ◽  
Author(s):  
Gautam Kalghatgi ◽  
Leif Hildingsson ◽  
Bengt Johansson
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Compression Ratio ◽  
Diesel Fuel ◽  
Ignition Delay ◽  
Cetane Number ◽  
Pressure Rise ◽  
Maximum Pressure ◽  
Single Cylinder ◽  
Intake Pressure

Much of the technology in advanced diesel engines, such as high injection pressures, is aimed at overcoming the short ignition delay of conventional diesel fuels to promote premixed combustion in order to reduce NOx and smoke. Previous work in a 2 l single-cylinder diesel engine with a compression ratio of 14 has demonstrated that gasoline fuel, because of its high ignition delay, is very beneficial for premixed compression-ignition compared with a conventional diesel fuel. We have now done similar studies in a smaller—0.537 l—single-cylinder diesel engine with a compression ratio of 15.8. The engine was run on three fuels of very different auto-ignition quality—a typical European diesel fuel with a cetane number (CN) of 56, a typical European gasoline of 95 RON and 85 MON with an estimated CN of 16 and another gasoline of 84 RON and 78 MON (estimated CN of 21). The previous results with gasoline were obtained only at 1200 rpm—here we compare the fuels also at 2000 rpm and 3000 rpm. At 1200 rpm, at low loads (∼4 bars indicated mean effective pressure (IMEP)) when smoke is negligible, NOx levels below 0.4 g/kWh can be easily attained with gasoline without using exhaust gas recirculation (EGR), while this is not possible with the 56 CN European diesel. At these loads, the maximum pressure-rise rate is also significantly lower for gasoline. At 2000 rpm, with 2 bars absolute intake pressure, NOx can be reduced below 0.4 g/kW h with negligible smoke (FSN<0.1) with gasoline between 10 bars and 12 bars IMEP using sufficient EGR, while this is not possible with the diesel fuel. At 3000 rpm, with the intake pressure at 2.4 bars absolute, NOx of 0.4 g/kW h with negligible smoke was attainable with gasoline at 13 bars IMEP. Hydrocarbon and CO emissions are higher for gasoline and will require after-treatment. High peak heat release rates can be alleviated using multiple injections. Large amounts of gasoline, unlike diesel, can be injected very early in the cycle without causing heat release during the compression stroke and this enables the heat release profile to be shaped.

Influence of Micro-Emulsified Biodiesel on Combustion and Emission Characteristics of a Turbocharged Diesel Engine

2012 ◽  
Vol 608-609 ◽  
pp. 269-274
Author(s):  
Qi Min Wu ◽  
Ping Sun ◽  
De Qing Mei ◽  
Zhen Chen
Keyword(s):  
Diesel Engine ◽  
Combustion Process ◽  
Pressure Rise ◽  
Operating Conditions ◽  
Maximum Pressure ◽  
Emission Characteristics ◽  
Combustion Duration ◽  
Rise Rate ◽  
Di Diesel Engine ◽  
Emulsified Biodiesel

In this paper, two kinds of micro-emulsified biodiesel containing 5.6% and10% water are prepared. The effects of micro-emulsified biodiesel on engine’s power, combustion and emission characteristics are investigated in a DI diesel engine. The results show that under the rated speed and full load operating conditions, the maximum pressure rise rate and peak heat release rate for micro-emulsified biodiesel increase dramatically, while the ignition delay is prolonged and the combustion duration becomes shorter. Compared to base diesel, the HC, CO and smoke emissions from the engine fueled with biodiesel decrease sharply, except for a 9% increased NOx at large loads. However, micro-biodiesel could significantly reduce the NOx and smoke emissions, except for the higher HC and CO emissions at low and medium loads. When fuelled with 10%MB, the NOx and smoke emissions are 9% and 90% lower than that of diesel, respectively. Results reported here suggest that the application of micro-emulsified biodiesel in diesel engines has a potential to improve combustion process and reduce NOx, PM emissions simultaneously.

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