The Effects of Hydrogen Addition on Natural Gas Engine Operation

1993 ◽  
Author(s):  
Michael R. Swain ◽  
Mirza J. Yusuf ◽  
Zafer Dülger ◽  
Matthew N. Swain
Keyword(s):  
Natural Gas ◽  
Engine Operation ◽  
Gas Engine ◽  
Natural Gas Engine ◽  
Hydrogen Addition

Air Fuel Dilution in a Pilot Ignited Direct Injection Natural Gas Engine: Pollutants, Performance, and System Level Considerations

2019 ◽  
Author(s):  
Aditya Prakash Singh ◽  
Gordon Patrick McTaggart-Cowan ◽  
Patrick Kirchen
Keyword(s):  
Natural Gas ◽  
Thermal Efficiency ◽  
High Pressures ◽  
Direct Injection ◽  
System Level ◽  
Engine Operation ◽  
Gas Engine ◽  
Natural Gas Engine ◽  
Fuel Dilution ◽  
The Impact

Abstract Dilution of natural gas fuel with air for use in a pilot ignited direct injection natural gas engine was investigated to evaluate the impact of this strategy on emissions and engine performance. A representative heavy-duty mode (mid to high-load at medium speed) was considered and the equivalence ratio (Φ) and exhaust gas recirculation (EGR) rates were varied from this representative mode. Air dilution resulted in a significant reduction in several pollutants: 90 to 97% reductions in black carbon particulate matter, 45 to 95% reductions in carbon monoxide, 68 to 85% reductions in total unburnt hydrocarbons. NOx emissions were found to increase by between 1.5 and 2.5x, depending on Φ and EGR, for a fixed combustion phasing. Beyond the emissions improvements, the gross indicated thermal efficiency increased by 2.5 percentage points at both high and low EGR rates. At higher EGR rates, this improvement was due to improved combustion efficiency, while the mechanism for efficiency improvement at lower EGR rates was unclear. The application of air-fuel dilution requires compressed air (> 300 bar) to mix with natural gas at high pressures. A system level analysis considered the compression power required by an industrial 3-stage reciprocating compressor and indicated that the gross indicated thermal efficiency improvements could compensate for the compression requirements for engine operation at high Φ.

Advanced Knock Detection for Diesel/Natural Gas Engine Operation

2016 ◽  
Vol 9 (3) ◽  
pp. 1571-1583 ◽  
Author(s):  
Martin Kirsten ◽  
Gerhard Pirker ◽  
Christoph Redtenbacher ◽  
Andreas Wimmer ◽  
Franz Chmela
Keyword(s):  
Natural Gas ◽  
Engine Operation ◽  
Gas Engine ◽  
Natural Gas Engine ◽  
Knock Detection

Experimental Investigations of Hydrogen-Natural Gas Engines for Maritime Applications

2018 ◽  
Author(s):  
Harsh D. Sapra ◽  
Youri Linden ◽  
Wim van Sluijs ◽  
Milinko Godjevac ◽  
Klaas Visser
Keyword(s):  
Fuel Cell ◽  
Natural Gas ◽  
Combustion Stability ◽  
Experimental Investigations ◽  
Gas Engine ◽  
Natural Gas Engines ◽  
Natural Gas Engine ◽  
Hydrogen Addition ◽  
Ship Propulsion ◽  
Operating Window

A novel ship propulsion concept employs natural gas to reduce ship emissions and improve overall ship propulsion efficiency. This concept proposes a serial integration of Solid Oxide Fuel Cell (SOFC) and a natural gas engine, while anode-off gas (gas at the fuel cell exhaust) is used in the natural gas engine. This study focusses on SOFC-gas engine integration by experimentally analyzing the effects of adding hydrogen, which is the main combustible component of the fuel cell anode-off gas, in marine natural gas engines. The overall challenge is to employ the anode-off gas to improve the performance of marine natural gas engines. To study the effects of anode-off gas combustion in natural gas engines, experiments with hydrogen addition in a marine natural gas engine of 500 kW rated power were performed. Natural gas was replaced with 10 % and 20 % of hydrogen, by volume, without any penalties in terms of output power. We found that the high combustion rate of hydrogen improved combustion stability, which allowed for better air-excess ratio control. Thus allowing leaning to higher air-excess ratios and extending the, otherwise, limited operating window. Hydrogen addition also improved brake thermal efficiency by 1.2 %, while keeping NOx emissions below the maritime emission regulations. The improvement in engine efficiency with a larger operating window may help improve the load-taking capabilities of marine natural gas engines.

Measurement of semi-volatiles in used natural gas engine oil using thermogravimetric analysis

2007 ◽  
Vol 8 (5) ◽  
pp. 439-448 ◽  
Author(s):  
G Mullins ◽  
J Truhan
Keyword(s):  
Thermogravimetric Analysis ◽  
Natural Gas ◽  
Combustion Engine ◽  
Inert Atmosphere ◽  
Engine Oil ◽  
Lubricating Oil ◽  
Engine Operation ◽  
Gas Engine ◽  
Natural Gas Engine ◽  
Constant Rate

Semi-volatile in internal combustion engine lubricating oil may be responsible for limiting service life and can lead to in-cylinder deposit formation. In order to measure semivolatile content, a new thermogravimetric analysis (TGA) procedure has been adapted from existing soot procedures to determine the levels of semi-volatile compounds in progressively aged lubricating oil samples from a natural gas engine dynamometer test cell run. The per cent weight remaining at 550 °C, while heated at a constant rate in an inert atmosphere, varied linearly with running time, viscosity, and oxidation and nitration. The method yielded reproducible run-to-run results and showed good agreement between helium and argon atmospheres. Mass spectroscopy data confirmed increased levels of high molecular weight species during engine operation. This method may be applicable to diesel engine oil samples.

Modeling the Performance of a Turbo-Charged Spark Ignition Natural Gas Engine With Cooled Exhaust Gas Recirculation

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Hailin Li ◽  
Ghazi A. Karim
Keyword(s):  
Natural Gas ◽  
Exhaust Gas Recirculation ◽  
Spark Ignition ◽  
Exhaust Gas ◽  
Engine Operation ◽  
Gas Engine ◽  
Natural Gas Engine ◽  
Auto Ignition ◽  
Wide Range ◽  
Gas Recirculation

A variety of gaseous fuels and a wide range of cooled exhaust gas recirculation (EGR) can be used in turbo-charged spark ignition (S.I.) gas engines. This makes the experimental investigation of the knocking behavior both unwieldy and uneconomical. Accordingly, it would be attractive to develop suitable effective predictive models that can be used to improve the understanding of the roles of various design and operating parameters and achieve a more optimized turbo-charged engine operation, particularly when EGR is employed. This paper presents the simulated performance of a turbo-charged S.I. natural gas engine when employing partially cooled EGR. A two-zone predictive model developed mainly for naturally aspirated S.I. engine applications of natural gas, described and validated earlier, was extended to consider applications employing turbo-chargers, intake charge after-coolers, and cooled EGR. A suitably detailed kinetic scheme involving 155 reaction steps and 39 species for the oxidation of natural gas is employed to examine the pre-ignition reactions of the unburned mixtures that can lead to knock prior to being fully consumed by the propagating flame. The model predicts the onset of knock and its intensity once end gas auto-ignition occurs. The effects of turbo-charging and cooled EGR on the total energy to be released through auto-ignition and its effect on the intensity of the resulting knock are considered. The consequences of changes in the effectiveness of after and EGR-coolers, lean operation and reductions in the compression ratio on engine performance parameters, especially the incidence of knock are examined. The benefits, limitations, and possible penalties of the application of fuel lean operation combined with cooled EGR are also examined and discussed.

Analysis of the Rotating Arc Spark Plug in a Natural Gas Engine

2005 ◽  
Author(s):  
Jim Tassitano ◽  
James E. Parks
Keyword(s):  
Natural Gas ◽  
Fuel Efficiency ◽  
Cost Effective ◽  
Combustion Stability ◽  
Engine Operation ◽  
Gas Engine ◽  
Natural Gas Engines ◽  
Natural Gas Engine ◽  
Spark Plug ◽  
Rotating Arc

Large natural gas engines are durable and cost-effective generators of power for distributed energy applications. Fuel efficiency is an important aspect of distributed generation since operating costs associated with fuel consumption are the major component of energy cost on a life-cycle basis; furthermore, higher fuel efficiency results in lower CO2 emissions. Leaner operation of natural gas engines can result in improved fuel efficiency; however, engine operation becomes challenging at leaner air-to-fuel ratios due to several factors. One factor in combustion control is ignition. At lean air-fuel mixtures, reliable and repeatable ignition is necessary to maintain consistent power production from the engine, and spark plug quality and durability play an important role in reliability of ignition. Here research of a novel spark plug design for lean natural gas engines is presented. The spark plug is an annular gap spark plug with a permanent magnet that produces a magnetic field that forces the spark to rotate during spark discharge. The rotating arc spark plug (RASP) has the potential to improve ignition system reliability and durability. In the study presented here, the RASP plug was operated in a small natural gas engine, and combustion stability (measured by the coefficient of variation of indicated mean effective pressure (IMEP)) was measured as a function of air-to-fuel ratio to characterize the ignition performance at lean mixtures. Comparisons were made to a standard J-plug spark plug.

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