Attainment of High Thermal Efficiency and Near-zero Emissions by Optimizing Injected Spray Configuration in Direct Injection Hydrogen Engines

In this study, the combustion and emissions characteristics of Reactivity Controlled Compression Ignition (RCCI) obtained by direct injection (DI) of S8 and port fuel injection (PFI) of n-butanol were compared with RCCI of ultra-low sulfur diesel #2 (ULSD#2) and PFI of n-butanol at 6 bar indicated mean effective pressure (IMEP) and 1500 rpm. S8 is a synthetic paraffinic kerosene (C6–C18) developed by Syntroleum and is derived from natural gas. S8 is a Fischer-Tropsch fuel that contains a low aromatic percentage (0.5 vol. %) and has a cetane number of 63 versus 47 of ULSD#2. Baselines of DI conventional diesel combustion (CDC), with 100% ULSD#2 and also DI of S8 were conducted. For both RCCI cases, the mass ratio of DI to PFI was set at 1:1. The ignition delay for the ULSD#2 baseline was found to be 10.9 CAD (1.21 ms) and for S8 was shorter at 10.1 CAD (1.12 ms). In RCCI, the premixed charge combustion has been split into two regions of high temperature heat release, an early one BTDC from ignition of ULSD#2 or S8, and a second stage, ATDC from n-butanol combustion. RCCI with n-butanol increased the NOx because the n-butanol contains 21% oxygen, while S8 alone produced 30% less NOx emissions when compared to the ULSD#2 baseline. The RCCI reduced soot by 80–90% (more efficient for S8). However, S8 alone showed a considerable increase in soot emissions compared with ULSD#2. The indicated thermal efficiency was the highest for the ULSD#2 and S8 baseline at 44%. The RCCI strategies showed a decrease in indicated thermal efficiency at 40% ULSD#2-RCCI and 42% and for S8-RCCI, respectively. S8 as a single fuel proved to be a very capable alternative to ULSD#2 in terms of combustion performance nevertheless, exhibited higher soot emissions that have been mitigated with the RCCI strategy without penalty in engine performance.

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Assessment of a Syngas-Diesel Dual Fuelled Compression Ignition Engine

ASME 2010 4th International Conference on Energy Sustainability, Volume 1 ◽

10.1115/es2010-90218 ◽

2010 ◽

Cited By ~ 4

Author(s):

Bibhuti B. Sahoo ◽

Niranjan Sahoo ◽

Ujjwal K. Saha

Keyword(s):

Diesel Engine ◽

Thermal Efficiency ◽

Gas Flow ◽

Direct Injection ◽

Dual Fuel ◽

Exhaust Gas ◽

Compression Ignition ◽

Gas Temperature ◽

Compression Ignition Engine ◽

Exhaust Gas Temperature

Synthesis gas (Syngas), a mixture of hydrogen and carbon monoxide, can be manufactured from natural gas, coal, petroleum, biomass, and even from organic wastes. It can substitute fossil diesel as an alternative gaseous fuel in compression ignition engines under dual fuel operation route. Experiments were conducted in a single cylinder, constant speed and direct injection diesel engine fuelled with syngas-diesel in dual fuel mode. The engine is designed to develop a power output of 5.2 kW at its rated speed of 1500 rpm under variable loads with inducted syngas fuel having H2 to CO ratio of 1:1 by volume. Diesel fuel as a pilot was injected into the engine in the conventional manner. The diesel engine was run at varying loads of 20, 40, 60, 80 and 100%. The performance of dual fuel engine is assessed by parameters such as thermal efficiency, exhaust gas temperature, diesel replacement rate, gas flow rate, peak cylinder pressure, exhaust O2 and emissions like NOx, CO and HC. Dual fuel operation showed a decrease in brake thermal efficiency from 16.1% to a maximum of 20.92% at 80% load. The maximum diesel substitution by syngas was found 58.77% at minimum exhaust O2 availability condition of 80% engine load. The NOx level was reduced from 144 ppm to 103 ppm for syngas-diesel mode at the best efficiency point. Due to poor combustion efficiency of dual fuel operation, there were increases in CO and HC emissions throughout the range of engine test loads. The decrease in peak pressure causes the exhaust gas temperature to rise at all loads of dual fuel operation. The present investigation provides some useful indications of using syngas fuel in a diesel engine under dual fuel operation.

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Influence of fuel injection strategies on efficiency and particulate emissions of gasoline and ethanol blends in a turbocharged multi-cylinder direct injection engine

International Journal of Engine Research ◽

10.1177/1468087419838393 ◽

2019 ◽

Vol 22 (1) ◽

pp. 152-164 ◽

Cited By ~ 3

Author(s):

Ripudaman Singh ◽

Taehoon Han ◽

Mohammad Fatouraie ◽

Andrew Mansfield ◽

Margaret Wooldridge ◽

...

Keyword(s):

Thermal Efficiency ◽

Fuel Injection ◽

Direct Injection ◽

Injection Timing ◽

Multiple Injection ◽

Fuel Mass ◽

Direct Injection Engine ◽

Fuel Blends ◽

Ethanol Blends ◽

Injection Strategies

The effects of a broad range of fuel injection strategies on thermal efficiency and engine-out emissions (CO, total hydrocarbons, NOx and particulate number) were studied for gasoline and ethanol fuel blends. A state-of-the-art production multi-cylinder turbocharged gasoline direct injection engine equipped with piezoelectric injectors was used to study fuels and fueling strategies not previously considered in the literature. A large parametric space was considered including up to four fuel injection events with variable injection timing and variable fuel mass in each injection event. Fuel blends of E30 (30% by volume ethanol) and E85 (85% by volume ethanol) were compared with baseline E0 (reference grade gasoline). The engine was operated over a range of loads with intake manifold absolute pressure from 800 to 1200 mbar. A combined application of ethanol blends with a multiple injection strategy yielded considerable improvement in engine-out particulate and gaseous emissions while maintaining or slightly improving engine brake thermal efficiency. The weighted injection spread parameter defined in this study, combined with the weighted center of injection timing defined in the previous literature, was found well suited to characterize multiple injection strategies, including the effects of the number of injections, fuel mass in each injection and the dwell time between injections.

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Reduction of Heat Loss and Improvement of Thermal Efficiency by Application of “Temperature Swing” Insulation to Direct-Injection Diesel Engines

SAE International Journal of Engines ◽

10.4271/2016-01-0661 ◽

2016 ◽

Vol 9 (3) ◽

pp. 1449-1459 ◽

Cited By ~ 28

Author(s):

Yoshifumi Wakisaka ◽

Minaji Inayoshi ◽

Kenji Fukui ◽

Hidemasa Kosaka ◽

Yoshihiro Hotta ◽

...

Keyword(s):

Heat Loss ◽

Diesel Engines ◽

Thermal Efficiency ◽

Direct Injection ◽

Temperature Swing

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A Numerical Study of NOx Reduction for a DI Diesel Engine With Complex Geometry

Journal of Energy Resources Technology ◽

10.1115/1.1627366 ◽

2004 ◽

Vol 126 (1) ◽

pp. 13-20 ◽

Cited By ~ 4

Author(s):

Renshan Liu ◽

Chao Zhang

Keyword(s):

Diesel Engine ◽

Thermal Efficiency ◽

Fuel Injection ◽

Complex Geometry ◽

Numerical Study ◽

Direct Injection ◽

Nox Reduction ◽

Geometrical Parameters ◽

Injection Timing ◽

Di Diesel Engine

A numerical study of NOx reduction for a Direct Injection (DI) Diesel engine with complex geometry, which includes intake/exhaust ports and moving valves, was carried out using the commercial computational fluid dynamics software KIVA-3v. The numerical simulations were conducted to investigate the effects of engine operating and geometrical parameters, including fuel injection timing, fuel injection duration, and piston bowl depth, on the NOx formation and the thermal efficiency of the DI Diesel engine. The tradeoff relationships between the reduction in NOx and the decrease in thermal efficiency were established.

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Factors Affecting Performance of Dual Fuel Compression Ignition Engines

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.388.217 ◽

2013 ◽

Vol 388 ◽

pp. 217-222

Author(s):

Mohamed Mustafa Ali ◽

Sabir Mohamed Salih

Keyword(s):

Diesel Engine ◽

Fuel Consumption ◽

Thermal Efficiency ◽

Fuel Injection ◽

Direct Injection ◽

Injection System ◽

Dual Fuel ◽

Injection Timing ◽

Compression Ignition ◽

Factors Affecting

Compression Ignition Diesel Engine use Diesel as conventional fuel. This has proven to be the most economical source of prime mover in medium and heavy duty loads for both stationary and mobile applications. Performance enhancements have been implemented to optimize fuel consumption and increase thermal efficiency as well as lowering exhaust emissions on these engines. Recently dual fueling of Diesel engines has been found one of the means to achieve these goals. Different types of fuels are tried to displace some of the diesel fuel consumption. This study is made to identify the most favorable conditions for dual fuel mode of operation using Diesel as main fuel and Gasoline as a combustion improver. A single cylinder naturally aspirated air cooled 0.4 liter direct injection diesel engine is used. Diesel is injected by the normal fuel injection system, while Gasoline is carbureted with air using a simple single jet carburetor mounted at the air intake. The engine has been operated at constant speed of 3000 rpm and the load was varied. Different Gasoline to air mixture strengths investigated, and diesel injection timing is also varied. The optimum setting of the engine has been defined which increased the thermal efficiency, reduced the NOx % and HC%.

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