Measurement of semi-volatiles in used natural gas engine oil using thermogravimetric analysis

2007 ◽  
Vol 8 (5) ◽  
pp. 439-448 ◽  
Author(s):  
G Mullins ◽  
J Truhan

Semi-volatile in internal combustion engine lubricating oil may be responsible for limiting service life and can lead to in-cylinder deposit formation. In order to measure semivolatile content, a new thermogravimetric analysis (TGA) procedure has been adapted from existing soot procedures to determine the levels of semi-volatile compounds in progressively aged lubricating oil samples from a natural gas engine dynamometer test cell run. The per cent weight remaining at 550 °C, while heated at a constant rate in an inert atmosphere, varied linearly with running time, viscosity, and oxidation and nitration. The method yielded reproducible run-to-run results and showed good agreement between helium and argon atmospheres. Mass spectroscopy data confirmed increased levels of high molecular weight species during engine operation. This method may be applicable to diesel engine oil samples.

1991 ◽  
Author(s):  
Mónica Graciela Vázquez ◽  
Patricia Errecalde ◽  
Sergio Fabián Seín ◽  
Daniel Gonzalez

Author(s):  
Aditya Prakash Singh ◽  
Gordon Patrick McTaggart-Cowan ◽  
Patrick Kirchen

Abstract Dilution of natural gas fuel with air for use in a pilot ignited direct injection natural gas engine was investigated to evaluate the impact of this strategy on emissions and engine performance. A representative heavy-duty mode (mid to high-load at medium speed) was considered and the equivalence ratio (Φ) and exhaust gas recirculation (EGR) rates were varied from this representative mode. Air dilution resulted in a significant reduction in several pollutants: 90 to 97% reductions in black carbon particulate matter, 45 to 95% reductions in carbon monoxide, 68 to 85% reductions in total unburnt hydrocarbons. NOx emissions were found to increase by between 1.5 and 2.5x, depending on Φ and EGR, for a fixed combustion phasing. Beyond the emissions improvements, the gross indicated thermal efficiency increased by 2.5 percentage points at both high and low EGR rates. At higher EGR rates, this improvement was due to improved combustion efficiency, while the mechanism for efficiency improvement at lower EGR rates was unclear. The application of air-fuel dilution requires compressed air (> 300 bar) to mix with natural gas at high pressures. A system level analysis considered the compression power required by an industrial 3-stage reciprocating compressor and indicated that the gross indicated thermal efficiency improvements could compensate for the compression requirements for engine operation at high Φ.


2016 ◽  
Vol 9 (3) ◽  
pp. 1571-1583 ◽  
Author(s):  
Martin Kirsten ◽  
Gerhard Pirker ◽  
Christoph Redtenbacher ◽  
Andreas Wimmer ◽  
Franz Chmela

1993 ◽  
Author(s):  
Michael R. Swain ◽  
Mirza J. Yusuf ◽  
Zafer Dülger ◽  
Matthew N. Swain

2014 ◽  
Vol 971-973 ◽  
pp. 680-683
Author(s):  
Gang Tian Chen

The relationship among the thermal parameters of supercharging system of internal combustion engine is very complicated. They affect and constrain each other. It is comparatively difficult to find out their changing rules and interactions, let alone the special supercharging system of natural gas engine. This paper is aimed to calculate and find out the internal connections among all parameters by rationally selecting parameters collected from experiences and establishing mathematical model for the supercharging thermal parameters of natural gas engine based on diesel engine’s supercharging estimation method, so as to provide theoretical basis for matching the supercharging system.


Author(s):  
Nikhil Dayanand ◽  
John D. Palazzotto ◽  
Alan T. Beckman

In order to investigate the possible environmental and economic benefits of lubricants optimized for stationary natural gas engine efficiency, a decision was made to develop a test stand to quantify the effects of lubricant viscosities and formulations on the brake specific fuel consumption. Many fuel economy tests already exist for evaluating gasoline and heavy duty diesel motor oils which have proven the benefit of fuel economy from different lubricant formulations. These engines would not be suitable tools for evaluating the fuel economy performance of lubricating oils formulated specifically for stationary natural gas engines, since there are significant differences in operating conditions, fuel type, and oil formulations. This paper describes the adaptation of a Waukesha VSG F11 GSID as a tool to evaluate fuel consumption performance. The performance of brake specific fuel consumption when using different formulations was measured at selected high loads and rated speed. The results of the testing program discuss the viscosity and additive effects of stationary natural gas engine oil formulations on brake specific fuel consumption. The results will detail the change in brake specific fuel consumption between natural gas engine oil formulations blended to varying viscosities and compared to a typical natural gas engine oil formulation with a viscosity of 13.8 cSt @ 100°C. The second portion of the test program explores the effect of different additive packages that were blended to the same finished oil viscosity. It was acknowledged that there were statistical differences in brake specific fuel consumption characteristics between lubricants different in viscosity and additive formulations.


Author(s):  
Hailin Li ◽  
Ghazi A. Karim

A variety of gaseous fuels and a wide range of cooled exhaust gas recirculation (EGR) can be used in turbo-charged spark ignition (S.I.) gas engines. This makes the experimental investigation of the knocking behavior both unwieldy and uneconomical. Accordingly, it would be attractive to develop suitable effective predictive models that can be used to improve the understanding of the roles of various design and operating parameters and achieve a more optimized turbo-charged engine operation, particularly when EGR is employed. This paper presents the simulated performance of a turbo-charged S.I. natural gas engine when employing partially cooled EGR. A two-zone predictive model developed mainly for naturally aspirated S.I. engine applications of natural gas, described and validated earlier, was extended to consider applications employing turbo-chargers, intake charge after-coolers, and cooled EGR. A suitably detailed kinetic scheme involving 155 reaction steps and 39 species for the oxidation of natural gas is employed to examine the pre-ignition reactions of the unburned mixtures that can lead to knock prior to being fully consumed by the propagating flame. The model predicts the onset of knock and its intensity once end gas auto-ignition occurs. The effects of turbo-charging and cooled EGR on the total energy to be released through auto-ignition and its effect on the intensity of the resulting knock are considered. The consequences of changes in the effectiveness of after and EGR-coolers, lean operation and reductions in the compression ratio on engine performance parameters, especially the incidence of knock are examined. The benefits, limitations, and possible penalties of the application of fuel lean operation combined with cooled EGR are also examined and discussed.


Author(s):  
Jim Tassitano ◽  
James E. Parks

Large natural gas engines are durable and cost-effective generators of power for distributed energy applications. Fuel efficiency is an important aspect of distributed generation since operating costs associated with fuel consumption are the major component of energy cost on a life-cycle basis; furthermore, higher fuel efficiency results in lower CO2 emissions. Leaner operation of natural gas engines can result in improved fuel efficiency; however, engine operation becomes challenging at leaner air-to-fuel ratios due to several factors. One factor in combustion control is ignition. At lean air-fuel mixtures, reliable and repeatable ignition is necessary to maintain consistent power production from the engine, and spark plug quality and durability play an important role in reliability of ignition. Here research of a novel spark plug design for lean natural gas engines is presented. The spark plug is an annular gap spark plug with a permanent magnet that produces a magnetic field that forces the spark to rotate during spark discharge. The rotating arc spark plug (RASP) has the potential to improve ignition system reliability and durability. In the study presented here, the RASP plug was operated in a small natural gas engine, and combustion stability (measured by the coefficient of variation of indicated mean effective pressure (IMEP)) was measured as a function of air-to-fuel ratio to characterize the ignition performance at lean mixtures. Comparisons were made to a standard J-plug spark plug.


Fuel ◽  
2019 ◽  
Vol 235 ◽  
pp. 1172-1183 ◽  
Author(s):  
Ping Yi ◽  
Wuqiang Long ◽  
Liyan Feng ◽  
Lei Chen ◽  
Jingchen Cui ◽  
...  

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