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.

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.

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.

Study on Modified Natural Gas Engine Considering NOx Emission

2013 ◽  
Vol 318 ◽  
pp. 371-374
Author(s):  
Chen Fan
Keyword(s):  
Diesel Engine ◽  
Natural Gas ◽  
Nox Emission ◽  
Emission Characteristics ◽  
Gas Engine ◽  
Natural Gas Engine ◽  
Low Nox Emission ◽  
Engine Power

There was a conflict between NOx emission and engine power of modified natural gas engine. Influence facters of NOx emission and emission characteristics of existing modified engine were studied. Emission and engine power of natural gas engine modified from gasoline and diesel engine were compared. Then some sugesstion are brought out for designing low NOx emission natural gas engine and promote engine power.

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.

Modeling of Formaldehyde Formation From Crevices in a Large Bore Natural Gas Engine

2007 ◽  
Author(s):  
Daniel B. Olsen ◽  
Ryan K. Palmer ◽  
Charles E. Mitchell
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Natural Gas ◽  
Kinetic Modeling ◽  
The United States ◽  
Chemical Kinetic ◽  
Formation Mechanisms ◽  
Gas Engine ◽  
Natural Gas Engines ◽  
Natural Gas Engine

Formaldehyde emissions from stationary natural gas engines are regulated in the United States, as mandated by the 1990 Clean Air Act Amendments. This work aims to advance the understanding of formaldehyde formation in large bore (>36 cm) natural gas engines. Formaldehyde formation in a large bore natural gas engine is modeled utilizing computational fluid dynamics and chemical kinetics. The top land crevice volume is believed to play an important role in the formation mechanisms of engine-out formaldehyde. This work focuses specifically on the top land crevice volume in the Cooper-Bessemer LSVB large bore 4-stroke cycle natural gas engine. Chemical kinetic modeling predicts that the top land crevice volume is responsible for the formation of 22 ppm of engine-out formaldehyde. Based on a raw exhaust concentration of 80 ppm, this constitutes about 27% of engine-out formaldehyde. Simplifying assumptions made for the chemical kinetic modeling are validated using computational fluid dynamics. Computational fluid dynamic analysis provided confirmation of crevice volume mass discharge timing. It also provided detailed pressure, temperature and velocity profiles within the top land crevice volume at various crank angle degrees.

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.

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