Numerical analysis of the combustion process in a four-stroke compressed natural gas engine with direct injection system

2008 ◽  
Vol 22 (10) ◽  
pp. 1937-1944 ◽  
Author(s):  
Wendy Hardyono Kurniawan ◽  
Shahrir Abdullah
Keyword(s):  
Numerical Analysis ◽  
Natural Gas ◽  
Direct Injection ◽  
Combustion Process ◽  
Injection System ◽  
Compressed Natural Gas ◽  
Gas Engine ◽  
Natural Gas Engine

The scavenging timing of pre-chamber on the performance of a natural gas engine

2020 ◽  
pp. 146808742096087
Author(s):  
Xue Yang ◽  
Yong Cheng ◽  
Pengcheng Wang
Keyword(s):  
Natural Gas ◽  
Combustion Process ◽  
Injection System ◽  
Maximum Pressure ◽  
Ignition Process ◽  
Main Chamber ◽  
Ignition Timing ◽  
Gas Engine ◽  
Natural Gas Engines ◽  
Natural Gas Engine

The pre-chamber ignition system scavenged with natural gas can effectively improve the in-cylinder combustion process and extend the lean-burn limit of natural gas engines. The scavenging process affects the flow field and fuel-air mixture concentration distribution in the pre-chamber and affects the combustion process in the pre-chamber as well as the ignition process in the main chamber. This has a significant influence on the performance of natural gas engines. It is supposed that the ratio of natural gas remaining in the mixture inside the pre-chamber at the ignition timing affects the combustion process in the pre-chamber. To verify this suppose, an independent injection system for injecting natural gas into the pre-chamber is designed and experiments are carried out on a single-cylinder natural gas engine. The ratio of natural gas remaining in the mixture inside the pre-chamber at the ignition timing is adjusted by changing the injection start angle of the scavenging process. The combustion process in the pre-chamber and the main chamber are analyzed using the in-cylinder pressures. The results indicate that, with the delay of the injection start angle, the ratio of natural gas remaining in the mixture inside the pre-chamber at the ignition timing increases, the combustion process in the pre-chamber is enhanced, the maximum pressure difference between two chambers increases and appears earlier. The energy of the hot jets and the penetration of the jets increase, which enhances the combustion process in the main chamber.

Selective NOx Recirculation for Stationary Lean-Burn Natural Gas Engines

2004 ◽  
Author(s):  
Chamila A. Tissera ◽  
Matt M. Swartz ◽  
Emre Tatli ◽  
Ramprabhu Vellaisamy ◽  
Nigel N. Clark ◽  
...  
Keyword(s):  
Natural Gas ◽  
Combustion Process ◽  
Injection System ◽  
Lean Burn ◽  
Desorption Process ◽  
Gas Engine ◽  
No Conversion ◽  
Natural Gas Engine ◽  
Fuel Ratio ◽  
Conversion Rates

NOx control in a lean burn natural gas engine is typically achieved with appropriate management of air/fuel ratio and ignition timing. A novel approach for further reduction involves the capture of NOx by first adsorbing the NOx from the exhaust stream, followed by the periodic desorption of NOx from an aftertreatment medium. Then, by passing the desorbed NOx gas into the intake air stream and back through the engine, a percentage of the NOx will be converted to harmless gases during the combustion process. The objective of this paper is to report the NOx conversion phenomenon during a lean combustion process. The results of this testing will be used to develop an optimal system for the conversion of NOx with a NOx adsorber. A 1993 Cummins L10-G spark ignited natural gas engine was used to conduct the experiments. Commercially available nitric oxide (NO, 98.8% purity) was injected into the engine intake to mimic the NOx stream from the desorption process to obtain NO conversion rates at various steady-state engine operating points. The NO injection system was capable of injecting NO at varying flow rates and time intervals. NO was injected into the intake manifold for ten and twenty second periods, and the conversion rates were calculated. When the injected NO amount increased from 0.22 g/s to 1.2 g/s and engine loads varied from 200ft-lb to 400ft-lb at 800 RPM, the NO conversion rates increased from 5% to 47%. It was observed that the air/fuel ratio, injected NO quantity and the engine load greatly effected the NO conversion rates. It was also noted that engine speed had a negligible affect when the intake NO concentration was held constant.

Experimental Test of a New Compressed Natural Gas Engine with Direct Injection

2009 ◽  
Author(s):  
M. A. Kalam ◽  
H. H. Masjuki ◽  
T. M. I. Mahlia ◽  
M. A. Fuad ◽  
Ku Halim ◽  
...  
Keyword(s):  
Natural Gas ◽  
Experimental Test ◽  
Direct Injection ◽  
Compressed Natural Gas ◽  
Gas Engine ◽  
Natural Gas Engine

The Combustion and Performance of a Converted Direct Injection Compressed Natural Gas Engine using Spark Plug Fuel Injector

2010 ◽  
Author(s):  
Taib Iskandar Mohamad ◽  
Ali Yusoff ◽  
Shahrir Abdullah ◽  
Mark Jermy ◽  
Matthew Harrison ◽  
...  
Keyword(s):  
Natural Gas ◽  
Direct Injection ◽  
Fuel Injector ◽  
Compressed Natural Gas ◽  
Gas Engine ◽  
Natural Gas Engine ◽  
Spark Plug ◽  
And Performance

Compressed-natural-gas optimised downsized demonstrator engine

2017 ◽  
Vol 232 (1) ◽  
pp. 75-89 ◽  
Author(s):  
Jonathan Hall ◽  
Benjamin Hibberd ◽  
Simon Streng ◽  
Michael Bassett
Keyword(s):  
Carbon Dioxide ◽  
Natural Gas ◽  
Fuel Consumption ◽  
Carbon Dioxide Emissions ◽  
Alternative Fuels ◽  
Direct Injection ◽  
Driving Performance ◽  
Compressed Natural Gas ◽  
Gas Engine ◽  
Natural Gas Engine

The complexity of modern powertrain development is demonstrated by the combination of requirements to meet future emission regulations and test procedures such as the real driving emissions, the reductions in the fuel consumption and the carbon dioxide emissions as well as the expectations of customers that there must be a good driving performance. Gasoline engine downsizing is already established as a proved technology to reduce the carbon dioxide emissions of automotive fleets. Additionally, alternative fuels such as natural gas offer the potential to reduce significantly both the tailpipe carbon dioxide emissions and the other regulated exhaust gas emissions without compromising the driving performance and the driving range. This paper presents results showing how the positive fuel properties of natural gas can be fully utilised in a heavily downsized engine. The engine was modified to cope with the significantly higher mechanical and thermal loads when operating at high specific outputs on compressed natural gas. In this study, peak cylinder pressures of up to 180 bar and specific power output levels of 110 kW/l were realised. It is also shown that having cylinder components specific to natural gas can yield significant reductions in the fuel consumption and, in conjunction with a variable-geometry turbine, a port-fuelled compressed-natural-gas engine can achieve a impressive low-speed torque (a brake mean effective power of 2700 kPa at 1500 r/min) and good transient response characteristics. The results achieved from the test engine while operating on compressed natural gas are compared with measurements from the baseline gasoline-fuelled direct-injection engine. In addition, a comparison between port fuel injection and direct injection of compressed natural gas is presented. This also includes an investigation into the specific performance challenges presented by port-fuel-injected compressed natural gas. The potential carbon dioxide savings offered by this heavily downsized compressed-natural-gas engine, of up to 50% at peak power and 20–40% for the driving-cycle region (including real-driving-emissions testing), are presented and discussed.

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