Simulation and performance comparison between diesel and natural gas engines for marine applications

2017 ◽  
Vol 231 (2) ◽  
pp. 690-704 ◽  
Author(s):  
Marco Altosole ◽  
Giovanni Benvenuto ◽  
Ugo Campora ◽  
Michele Laviola ◽  
Raphael Zaccone
Keyword(s):  
Natural Gas ◽  
Diesel Oil ◽  
Performance Comparison ◽  
Pollutant Emissions ◽  
Natural Gas Engines ◽  
Marine Engines ◽  
Prime Movers ◽  
And Performance ◽  
Marine Applications ◽  
Continuous Power

The article shows the performance comparison between two marine engines, fuelled by natural gas and diesel oil, respectively, both belonging to the ‘Bergen’ engine series of Rolls-Royce Marine, suitable as prime movers for ship propulsion. Two different simulation codes, one for each engine, validated by means of geometrical and performance data provided by the manufacturer, have been developed to extend the comparison to the whole working area of the examined engines. Although the maximum continuous power is very similar (about 2 MW at the same rotational speed), some differences exist in size, efficiency and pollutant emissions of the two types of engines. The reasons are investigated through a specific thermodynamic analysis, aimed to explain such differences, in terms of efficiency and emissions (particularly carbon dioxide), when varying the working conditions. The analysis is carried out by comparing the respective real cycles, at the same working condition, and repeating the comparison for different engine delivered powers and rotational speeds. In addition, a study of the different modes of combustion is developed to explain the major differences found in the emissions of nitrogen oxides.

scholarly journals Lean-Burn Natural Gas Engines: Challenges and Concepts for an Efficient Exhaust Gas Aftertreatment System

2020 ◽  
Author(s):  
Patrick Lott ◽  
Olaf Deutschmann
Keyword(s):  
Natural Gas ◽  
Carbon Dioxide Emissions ◽  
Rational Design ◽  
Catalytic Converter ◽  
Pollutant Emissions ◽  
Exhaust Gas ◽  
Lean Burn ◽  
Aftertreatment System ◽  
Natural Gas Engines ◽  
Exhaust Gas Aftertreatment

AbstractHigh engine efficiency, comparably low pollutant emissions, and advantageous carbon dioxide emissions make lean-burn natural gas engines an attractive alternative compared to conventional diesel or gasoline engines. However, incomplete combustion in natural gas engines results in emission of small amounts of methane, which has a strong global warming potential and consequently makes an efficient exhaust gas aftertreatment system imperative. Palladium-based catalysts are considered as most effective in low temperature methane conversion, but they suffer from inhibition by the combustion product water and from poisoning by sulfur species that are typically present in the gas stream. Rational design of the catalytic converter combined with recent advances in catalyst operation and process control, particularly short rich periods for catalyst regeneration, allow optimism that these hurdles can be overcome. The availability of a durable and highly efficient exhaust gas aftertreatment system can promote the widespread use of lean-burn natural gas engines, which could be a key step towards reducing mankind’s carbon footprint.

Poison Build-up and Performance Degradation of an Oxidation Catalyst in 2-Stroke Natural Gas Engine Exhaust

2017 ◽  
Author(s):  
Marc E. Baumgardner ◽  
Daniel B. Olsen
Keyword(s):  
Natural Gas ◽  
Catalyst Deactivation ◽  
Catalyst Surface ◽  
Oxidation Catalyst ◽  
Lean Burn ◽  
Gas Field ◽  
Natural Gas Engines ◽  
Engine Testing ◽  
And Performance ◽  
Carry Over

Due to current and future exhaust emissions regulations, oxidation catalysts are increasingly being added to the exhaust streams of large-bore, 2-stroke, natural gas engines. Such catalysts have been found to have a limited operational lifetime, primarily due to chemical (i.e. catalyst poisoning) and mechanical fouling resulting from the carry-over of lubrication oil from the cylinders. It is critical for users and catalyst developers to understand the nature and rate of catalyst deactivation under these circumstances. This study examines the degradation of an exhaust oxidation catalyst on a large-bore, 2-stroke, lean-burn, natural gas field engine over the course of 2 years. Specifically this work examines the process by which the catalyst was aged and tested and presents a timeline of catalyst degradation under commercially relevant circumstances. The catalyst was aged in the field for 2 month intervals in the exhaust slipstream of a GMVH-12 engine and intermittently brought back to the Colorado State Engines and Energy Conversion Laboratory for both engine testing and catalyst surface analysis. Engine testing consisted of measuring catalyst reduction efficiency as a function of temperature as well as the determination of the light-off temperature for several exhaust components. The catalyst surface was analyzed via SEM/EDS and XPS techniques to examine the location and rate of poison deposition. After 2 years on-line the catalyst light-off temperature had increased ∼55°F (31°C) and ∼34 wt% poisons (S, P, Zn) were built up on the catalyst surface, both of which represent significant catalyst deactivation.

Advanced Gas Engine Cogeneration Technology for Special Applications

1995 ◽  
Vol 117 (4) ◽  
pp. 826-831 ◽  
Author(s):  
D. C. Plohberger ◽  
T. Fessl ◽  
F. Gruber ◽  
G. R. Herdin
Keyword(s):  
Natural Gas ◽  
Ambient Air ◽  
Pollutant Emissions ◽  
Thermal Reactor ◽  
Maximum Efficiency ◽  
Exhaust Aftertreatment ◽  
Natural Gas Engines ◽  
Low Emission ◽  
Wide Range ◽  
The U.S

In recent years gas Otto-cycle engines have become common for various applications in the field of power and heat generation. Gas engines in gen-sets and cogeneration plants can be found in industrial sites, oil and gas field application, hospitals, public communities, etc., mainly in the U.S., Japan, and Europe, and with an increasing potential in the upcoming areas in the far east. Gas engines are chosen sometimes even to replace diesel engines, because of their clean exhaust emission characteristics and the ample availability of natural gas in the world. The Austrian Jenbacher Energie Systeme AG has been producing gas engines in the range of 300 to 1600 kW since 1960. The product program covers state-of-the-art natural gas engines as well as advanced applications for a wide range of alternative gas fuels with emission levels comparable to Low Emission (LEV) and Ultra Low Emission Vehicle (ULEV) standards. In recent times the demand for special cogeneration applications is rising. For example, a turnkey cogeneration power plant for a total 14.4 MW electric power and heat output consisting of four JMS616-GSNLC/B spark-fired gas engines specially tuned for high altitude operation has been delivered to the well-known European ski resort of Sestriere. Sestriere is situated in the Italian Alps at an altitude of more than 2000 m (approx. 6700 ft) above sea level. The engines feature a turbocharging system tuned to an ambient air pressure of only 80 kPa to provide an output and efficiency of each 1.6 MW and up to 40 percent @ 1500 rpm, respectively. The ever-increasing demand for lower pollutant emissions in the U.S. and some European countries initiates developments in new exhaust aftertreatment technologies. Thermal reactor and Selective Catalytic Reduction (SCR) systems are used to reduce tailpipe CO and NOx emissions of engines. Both SCR and thermal reactor technology will shift the engine tuning to achieve maximum efficiency and power output. Development results are presented, featuring the ultra low emission potential of biogas and natural gas engines with exhaust aftertreatment.

scholarly journals The influence of natural gas additive on the smoke level generated by diesel engines

2015 ◽  
Vol 161 (2) ◽  
pp. 78-88
Author(s):  
Zdzisław STELMASIAK ◽  
Jerzy LARISCH ◽  
Dariusz PIETRAS
Keyword(s):  
Natural Gas ◽  
Engine Speed ◽  
Diesel Oil ◽  
Operating Conditions ◽  
Exhaust Gas ◽  
Chassis Dynamometer ◽  
Natural Gas Engines ◽  
Smoke Opacity ◽  
Small Additive ◽  
Selection Of

The paper presents the results of investigations performed on a Fiat 1.3 MultiJet engine fueled with natural gas (CNG) and diesel oil. The primary aim was to determine the influence of a small additive of natural gas on the exhaust gas opacity under variable engine operating conditions. The tests were performed for the engine work points n–Mo (engine speed– torque) reproducing the NEDC cycle. The selection of the work points was carried out according to the criterion of greatest share in the NEDC homologation test, covering the entire engine field of work used in the realization of the test on a chassis dynamometer. In the tests, the authors applied different energy shares of natural gas in the range 15–35.6%. The smoke opacity was analyzed in the FSN and mass scales [mg/m3 ]. The results of the investigations may be used in the design of electronic controllers for natural gas engines and in the adaptation engines to CNG fueling.

Development of the Tracer Gas Method for Large Bore Natural Gas Engines—Part II: Measurement of Scavenging Parameters

2002 ◽  
Vol 124 (3) ◽  
pp. 686-694 ◽  
Author(s):  
D. B. Olsen ◽  
G. C. Hutcherson ◽  
B. D. Willson ◽  
C. E. Mitchell
Keyword(s):  
Natural Gas ◽  
Operating Conditions ◽  
Trapping Efficiency ◽  
Pollutant Emissions ◽  
Boost Pressure ◽  
Tracer Gas ◽  
Gas Industry ◽  
Natural Gas Engines ◽  
Natural Gas Industry ◽  
Scavenging Efficiency

In this work the tracer gas method using nitrous oxide as the tracer gas is implemented on a stationary two-stroke cycle, four-cylinder, fuel-injected large-bore natural gas engine. The engine is manufactured by Cooper-Bessemer, model number GMV-4TF. It is representative of the large bore natural gas stationary engine fleet currently in use by the natural gas industry for natural gas compression and power generation. Trapping efficiency measurements are carried out with the tracer gas method at various engine operating conditions, and used to evaluate the scavenging efficiency and trapped A/F ratio. Scavenging efficiency directly affects engine power and trapped A/F ratio has a dramatic impact on pollutant emissions. Engine operating conditions are altered through variations in boost pressure, speed, back pressure, and intake port restriction.

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