Numerical Simulations of Mixture Formation in Combustion Chambers of Lean-Burn Natural Gas Engines Incorporating a Sub-Chamber

2017 ◽  
Author(s):  
Yuzuru Nada ◽  
So Morimoto ◽  
Yoshiyuki Kidoguchi ◽  
Ryu Kaya ◽  
Hideaki Nakano ◽  
...  
Keyword(s):  
Natural Gas ◽  
Numerical Simulations ◽  
Combustion Chambers ◽  
Mixture Formation ◽  
Lean Burn ◽  
Natural Gas Engines

scholarly journals Emission of Toxic HCN During NO x Removal by Ammonia SCR in the Exhaust of Lean‐Burn Natural Gas Engines

2020 ◽  
Vol 59 (34) ◽  
pp. 14423-14428 ◽  
Author(s):  
Deniz Zengel ◽  
Pirmin Koch ◽  
Bentolhoda Torkashvand ◽  
Jan‐Dierk Grunwaldt ◽  
Maria Casapu ◽  
...  
Keyword(s):  
Natural Gas ◽  
Lean Burn ◽  
Natural Gas Engines

Experimental study of combustion strategy for jet ignition on a natural gas engine

2020 ◽  
pp. 146808742097775
Author(s):  
Ziqing Zhao ◽  
Zhi Wang ◽  
Yunliang Qi ◽  
Kaiyuan Cai ◽  
Fubai Li
Keyword(s):  
Experimental Study ◽  
Natural Gas ◽  
Efficient Points ◽  
Lean Burn ◽  
Gas Engine ◽  
Absolute Value ◽  
Natural Gas Engines ◽  
Natural Gas Engine ◽  
Excess Air ◽  
Lean Limit

To explore a suitable combustion strategy for natural gas engines using jet ignition, lean burn with air dilution, stoichiometric burn with EGR dilution and lean burn with EGR dilution were investigated in a single-cylinder natural gas engine, and the performances of two kinds of jet ignition technology, passive jet ignition (PJI) and active jet ignition (AJI), were compared. In the study of lean burn with air dilution strategy, the results showed that AJI could extend the lean limit of excess air ratio (λ) to 2.1, which was significantly higher than PJI’s 1.6. In addition, the highest indicated thermal efficiency (ITE) of AJI was shown 2% (in absolute value) more than that of PJI. Although a decrease of NOx emission was observed with increasing λ in the air dilution strategy, THC and CO emissions increased. Stoichiometric burn with EGR was proved to be less effective, which can only be applied in a limited operation range and had less flexibility. However, in contrast to the strategy of stoichiometric burn with EGR, the strategy of lean burn with EGR showed a much better applicability, and the highest ITE could achieve 45%, which was even higher than that of lean burn with air dilution. Compared with the most efficient points of lean burn with pure air dilution, the lean burn with EGR dilution could reduce 78% THC under IMEP = 1.2 MPa and 12% CO under IMEP = 0.4 MPa. From an overall view of the combustion and emission performances under both low and high loads, the optimum λ would be from 1.4 to 1.6 for the strategy of lean burn with EGR dilution.

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.

Evaluation of a Lean-Burn Natural Gas Engine Operating on Variable Methane Number Fuel

2011 ◽  
Author(s):  
Cory J. Kreutzer ◽  
Daniel B. Olsen ◽  
Robin J. Bremmer
Keyword(s):  
Natural Gas ◽  
High Efficiency ◽  
Engine Performance ◽  
Combustion Stability ◽  
Lean Burn ◽  
Natural Gas Engines ◽  
Spark Timing ◽  
Gas Compression ◽  
Fuel Blending ◽  
Methane Number

Wellhead gas from which pipeline natural gas originates has significant variability in composition due to natural variations in deposits. Gas quality is influenced by relative concentrations of both inert and hydrocarbon species. Gas compression engines utilizing wellhead gas as a fuel source often require significant installation time and adjustment of stock configuration due to fuel compositions that vary with time and location. Lean burn natural gas engines are chosen as wellhead compression engines for high efficiency and low emissions while minimizing the effect of variable gas composition. Ideal engine conditions are maintained by operating within the knock and misfire limits of the engine. Additional data is needed to find engine operational limitations. In this work, experimental data was collected on a Cummins GTA8.3SLB engine operating on variable methane number fuel under closed-loop equivalence ratio control. A fuel blending system was used to vary methane number to simulate wellhead compositions. NOx and CO emissions were found to increase with decreasing methane number while combustion stability remained constant. In addition, the effects of carbon dioxide and nitrogen diluents in the fuel were investigated. When diluents were present in the fuel, engine performance could be maintained by spark timing advance.

scholarly journals COMPARATIVE ANALYSIS OF NATURAL GAS ENGINE PARAMETERS WITH QUALITY AND QUANTITY CONTROL

2014 ◽  
Vol 46 (1) ◽  
pp. 85-93
Author(s):  
Mikhail Shatrov ◽  
Aleksej Khatchiyan ◽  
Vladimir Sinyavskiy ◽  
Ivan Shishlov ◽  
Andrey Vakulenko
Keyword(s):  
Diesel Engine ◽  
Natural Gas ◽  
Power Level ◽  
Level Control ◽  
Mixture Formation ◽  
Gas Engine ◽  
Natural Gas Engines ◽  
Natural Gas Engine ◽  
Organization Analysis ◽  
Quantity Control

Parameters of natural gas engines were calculated with the aim to determine the optimal way of their working process organization. Analysis of calculations results demonstrated that quality power level control ensured the improvement of parameters of investigated engines. Calculations showed that compared with the diesel engine, the gas engine with quantity power level control, internal mixture formation and glow plug ignition of the gas-air mixture ensured the decrease of СО2 emissions by 26.8%, and the natural gas engine with quality power level control, external mixture formation and gas-air mixture ignition by a small pilot portion of fine atomized diesel fuel supplied by a Common Rail fuel system – by 25.5%. Therefore, one can choose one or another method of diesel engine conversion for operation on gas fuel considering available technical opportunities and with minimal expenses.

scholarly journals SELECTIVE NOx RECIRCULATION FOR STATIONARY LEAN-BURN NATURAL GAS ENGINES

2005 ◽  
Author(s):  
Nigel Clark ◽  
Gregory Thompson ◽  
Richard Atkinson ◽  
Chamila Tissera ◽  
Matt Swartz ◽  
...  
Keyword(s):  
Natural Gas ◽  
Lean Burn ◽  
Natural Gas Engines

Experience With Gas Engines Optimized for H2-Rich Fuels

2003 ◽  
Author(s):  
G. R. Herdin ◽  
F. Gruber ◽  
D. Plohberger ◽  
M. Wagner
Keyword(s):  
Natural Gas ◽  
Fuel Efficiency ◽  
Electrical Power ◽  
Nox Emissions ◽  
Engine Emissions ◽  
Lean Burn ◽  
Good Efficiency ◽  
Gas Engine ◽  
Natural Gas Engines ◽  
Fuel Technology

The gas engine is a very efficient possibility of a technological approach for the conversion of chemically bound energy into mechanical or electrical power. Degrees of efficiency achieved thus far through the electrification of natural gas amount to up to 45% depending on the engine size and further potentials are already being opened up. Gas engines therefore do not need to fear a comparison with diesel engines in terms of efficiency. The modern gas engines have considerable advantages regarding emissions. The state of the art for the NOx emissions of natural gas engines can presently be given as 0.7 g/kWh (diesel 5 g NOx/kWh) with practically particle-free combustion. As a result of these features the gas engine is especially suitable for the very efficient process of cogeneration of heat and power, through which total degrees of fuel efficiency of about 90% can be attained. As such, the gas engine is even superior to all previously introduced types of fuel cells. The utilization of H2-rich gases as fuel can be seen as a new field of application of gas engines. Jenbacher AG already has many years of experience in the field of “H2-rich fuels” with optimization of combustion control and mixture formation. The H2 content extend from 100% to very low caloric values of gases in the range of 1.67 MJ/Nm3. The gases to be utilized by the gas engines come primarily from thermal pyrolysis processes of biomass or RDF fuels. A very good efficiency behavior with uncommonly low NOx emissions can be determined as the common result of all gas engine sizes. In the case of the high NH3 content of e.g. wood gas, despite the extreme lean-burn operation through the primary formation of NOx from the fuel, no NOx minimum can be attained. For the future, making the step into H2-rich fuel technology particularly regarding emissions means a big step towards the low NOx concepts and thus the further reduction of engine emissions.

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