Formaldehyde Characterization Utilizing In-Cylinder Sampling in a Large Bore Natural Gas Engine

2000 ◽  
Vol 123 (3) ◽  
pp. 669-676 ◽  
Author(s):  
D. B. Olsen ◽  
J. C. Holden ◽  
G. C. Hutcherson ◽  
B. D. Willson
Keyword(s):  
Natural Gas ◽  
Combustion Process ◽  
Critical Time ◽  
Sampling Techniques ◽  
Test Results ◽  
Gas Engine ◽  
Natural Gas Engines ◽  
Natural Gas Engine ◽  
Future Work ◽  
Stroke Cycle

This research addresses the growing need to better understand the mechanisms through which engine-out formaldehyde is formed in two-stroke cycle large bore natural gas engines. The investigation is performed using a number of different in-cylinder sampling techniques implemented on a Cooper-Bessemer GMV-4TF four-cylinder two-stroke cycle large bore natural gas engine with a 36-cm (14-in.) bore and a 36-cm (14-in.) stroke. The development and application of various in-cylinder sampling techniques is described. Three different types of valves are utilized, (1) a large sample valve for extracting a significant fraction of the cylinder mass, (2) a fast sample valve for crank angle resolution, and (3) check valves. Formaldehyde in-cylinder sampling data are presented that show formaldehyde mole fractions at different times during the engine cycle and at different locations in the engine cylinder. The test results indicate that the latter part of the expansion process is a critical time for engine-out formaldehyde formation. The data show that significant levels of formaldehyde form during piston and end-gas compression. Additionally, formaldehyde is measured during the combustion process at mole fractions five to ten times higher than engine-out formaldehyde mole fractions. Formaldehyde is nearly completely destroyed during the final part of the combustion process. The test results provide insights that advance the current understanding and help direct future work on formaldehyde formation.

Development of the Tracer Gas Method for Large Bore Natural Gas Engines—Part I: Method Validation

2002 ◽  
Vol 124 (3) ◽  
pp. 678-685 ◽  
Author(s):  
D. B. Olsen ◽  
G. C. Hutcherson ◽  
B. D. Willson ◽  
C. E. Mitchell
Keyword(s):  
Nitrous Oxide ◽  
Natural Gas ◽  
Sampling Techniques ◽  
Tracer Gas ◽  
Gas Engine ◽  
Natural Gas Engines ◽  
Natural Gas Engine ◽  
Gas Measurements ◽  
Scavenging Efficiency ◽  
Stroke Cycle

The tracer gas method is investigated as a means to study scavenging in fuel-injected large-bore two-stroke cycle engines. The investigation is performed on a Cooper-Bessemer GMV-4TF natural gas engine, with a 36-cm bore and a 36-cm stroke. Two important parameters are evaluated from the tracer gas measurements, which are scavenging efficiency and trapped A/F ratio. Measurements with the tracer gas method are compared with in-cylinder sampling techniques to evaluate the accuracy of the method. Two different tracers are evaluated, monomethylamine and nitrous oxide. Monomethylamine is investigated because of its common use historically as a tracer gas. Nitrous oxide is a new tracer gas that overcomes many of the difficulties experienced with monomethylamine. The tracer gas method with nitrous oxide is determined to be accurate for evaluating scavenging efficiency and trapped A/F ratio in comparison to the in-cylinder sampling techniques implemented.

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.

CFD Modeling of the Performance of a Prechamber for Use in a Large Bore Natural Gas Engine

2005 ◽  
Author(s):  
Allan Kirkpatrick ◽  
Gi-Heon Kim ◽  
Daniel Olsen
Keyword(s):  
Natural Gas ◽  
Fuel Injection ◽  
Combustion Process ◽  
Three Dimensional ◽  
Cfd Modeling ◽  
Main Chamber ◽  
Gas Engine ◽  
Natural Gas Engines ◽  
Natural Gas Engine ◽  
Cfd Models

The topic of this paper is the performance of a prechamber for use in a large bore two stroke natural gas engine. With increased regulation of emissions from stationary natural gas engines, there has been interest in modification of the combustion process, such as extending the lean limit, to reduce NOx emissions. One promising combustion technique uses an ignition prechamber. CFD models of a prechamber and the cylinder were developed in order to simulate the performance of a prechamber ignition system. The modeling included a full three dimensional transient analysis with scavenging, moving piston, and main chamber fuel injection. The CFD analysis included the fuel injection into the prechamber, pressurization by the inflowing main chamber gases, spark ignition, combustion, and flame propagation into the main combustion chamber. The computations indicated that the prechamber is more well mixed than the main engine chamber, with the prechamber mixture close to stoichiometric for better ignition. There is a strong, well-organized vortex in the prechamber induced by the incoming jet from the main chamber. The combustion flame in the prechamber travels in the direction of the gas vortex along lines of increasing equivalence ratio. The flame then propagates across the main cylinder in a very uniform fashion, indicating that there is sufficient energy to ignite the lean, partially mixed mixture in the main chamber. The orientation of the prechamber nozzle was also investigated, and an orientation of twenty degrees relative to the main chamber was found to produce a flame that did not impinge on the piston.

Numerical Simulation of Marine Diesel Ignited Natural Gas Engine Based on the Finite Volume Method

2014 ◽  
Vol 926-930 ◽  
pp. 3124-3127
Author(s):  
Hong Liang Yu ◽  
Feng Shuo Xing ◽  
Shu Lin Duan
Keyword(s):  
Numerical Simulation ◽  
Natural Gas ◽  
Finite Volume ◽  
Combustion Process ◽  
Combustion Model ◽  
Emission Characteristics ◽  
Gas Engine ◽  
Natural Gas Engines ◽  
Natural Gas Engine ◽  
Marine Diesel

Currently, the research of marine natural gas engine is rare, while the combustion and emission characteristics of natural gas engine are affected greatly by the diesel ignition. This paper built a finite volume combustion model of diesel ignited natural gas engine by AVL FIRE software, and compared experimental data to prove the accuracy of the model, and numerical simulation of the combustion process that the diesel ignited natural gas was carried, analyzed the combustion and emission characteristics of natural gas engines, provided a theoretical basis for the further optimize and design of marine natural gas engine.

Railplug Design Optimization to Improve Large-Bore Natural Gas Engine Performance

2005 ◽  
Author(s):  
Hongxun Gao ◽  
Matt J. Hall ◽  
Ofodike A. Ezekoye ◽  
Ron D. Matthews
Keyword(s):  
Natural Gas ◽  
High Energy ◽  
Parameter Study ◽  
Transfer Model ◽  
High Speed Photography ◽  
Discharge Process ◽  
Ignition System ◽  
Gas Engine ◽  
Natural Gas Engines ◽  
Natural Gas Engine

It is a very challenging problem to reliably ignite extremely lean mixtures, especially for the low speed, high load conditions of stationary large-bore natural gas engines. If these engines are to be used for the distributed power generation market, it will require operation with higher boost pressures and even leaner mixtures. Both place greater demands on the ignition system. The railplug is a very promising ignition system for lean burn natural gas engines with its high-energy deposition and high velocity plasma jet. High-speed photography was used to study the discharge process. A heat transfer model is proposed to aid the railplug design. A parameter study was performed both in a constant volume bomb and in an operating natural gas engine to improve and optimize the railplug designs. The engine test results show that the newly designed railplugs can ensure the ignition of very lean natural gas mixtures and extend the lean stability limit significantly. The new railplug designs also improve durability.

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.

Analysis of chaos in the combustion process of premixed natural gas engine

2017 ◽  
Vol 121 ◽  
pp. 768-778 ◽  
Author(s):  
Shun-Liang Ding ◽  
En-Zhe Song ◽  
Li-Ping Yang ◽  
Grzegorz Litak ◽  
Yu-Yuan Wang ◽  
...  
Keyword(s):  
Natural Gas ◽  
Combustion Process ◽  
Gas Engine ◽  
Natural Gas Engine

Laser Ignition of Natural Gas Engines Using Fiber Delivery

2005 ◽  
Author(s):  
Azer P. Yalin ◽  
Morgan W. Defoort ◽  
Sachin Joshi ◽  
Daniel Olsen ◽  
Bryan Willson ◽  
...  
Keyword(s):  
Natural Gas ◽  
Past Research ◽  
Spark Ignition ◽  
Laser Source ◽  
Laser Ignition ◽  
Ignition System ◽  
Gas Engine ◽  
Natural Gas Engines ◽  
Natural Gas Engine ◽  
Design Concepts

A practical impediment to implementation of laser ignition systems has been the open-path beam delivery used in past research. In this contribution, we present the development and implementation of a fiber-optically delivery laser spark ignition system. To our knowledge, the work represents the first demonstration of fiber coupled laser ignition (using a remote laser source) of a natural gas engine. A Nd:YAG laser is used as the energy source and a coated hollow fiber is used for beam energy delivery. The system was implemented on a single-cylinder of a Waukesha VGF 18 turbo charged natural gas engine and yielded consistent and reliable ignition. In addition to presenting the design and testing of the fiber delivered laser ignition system, we present initial design concepts for a multiplexer to ignite multiple cylinders using a single laser source, and integrated optical diagnostic approaches to monitor the spark ignition and combustion performance.

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.

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