scholarly journals Investigation of cycle skipping methods in an engine converted to positive ignition natural gas engine

2021 ◽  
Vol 13 (9) ◽  
pp. 168781402110454
Author(s):  
Erdal Tunçer ◽  
Tarkan Sandalcı ◽  
Yasin Karagöz
Keyword(s):  
Natural Gas ◽  
Fuel Consumption ◽  
Electronic Control Unit ◽  
Engine Performance ◽  
Control Unit ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Specific Fuel Consumption ◽  
Electronic Throttle ◽  
Operating Modes

In this study, a single cylinder of 1.16 L, naturally aspirated engine was converted to a spark ignition engine, which was a diesel engine operating with natural gas as fuel. By placing electronic throttle, electronic ignition module, gas fuel injectors and proximity sensors on the test engine, the engine has been turned into a positive ignition engine that can work with natural gas as fuel, thanks to the electronic control unit developed by our project team. Then, in the study performed, different cycle skipping strategies were experimentally investigated at a constant engine speed of 1565 rpm, in accordance with the generator operating conditions. Engine performance, emissions (CO, HC, and NOx), and combustion characteristics (cylinder pressure, rate of heat release, etc.) of cycle skipping strategies were experimentally investigated with natural gas as fuel in Normal, 3N1S, 2N1S, and 1N1S engine operating modes. According to the results obtained, specific fuel consumption, CO and HC values improved in all cycle skipping operating conditions, except for NOx, but the best results were obtained in 2N1S operating conditions; it was concluded that the specific fuel consumption, CO and HC values improved by 11.19%, 61.89%, and 65.60%, respectively.

scholarly journals Experimental Assessment of the Performance and Emissions of a Spark-Ignition Engine Using Waste-Derived Biofuels as Additives

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5209
Author(s):  
Joaquim Costa ◽  
Jorge Martins ◽  
Tiago Arantes ◽  
Margarida Gonçalves ◽  
Luis Durão ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Electronic Control Unit ◽  
Engine Performance ◽  
Control Unit ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Pollutant Emissions ◽  
Low Grade ◽  
Performance And Emissions ◽  
Fuel Mixtures

The use of biofuels for spark ignition engines is proposed to diversify fuel sources and reduce fossil fuel consumption, optimize engine performance, and reduce pollutant emissions. Additionally, when these biofuels are produced from low-grade wastes, they constitute valorisation pathways for these otherwise unprofitable wastes. In this study, ethanol and pyrolysis biogasoline made from low-grade wastes were evaluated as additives for commercial gasoline (RON95, RON98) in tests performed in a spark ignition engine. Binary fuel mixtures of ethanol + gasoline or biogasoline + gasoline with biofuel incorporation of 2% (w/w) to 10% (w/w) were evaluated and compared with ternary fuel mixtures of ethanol + biogasoline + gasoline with biofuel incorporation rates from 1% (w/w) to 5% (w/w). The fuel mix performance was assessed by determination of torque and power, fuel consumption and efficiency, and emissions (HC, CO, and NOx). An electronic control unit (ECU) was used to regulate the air–fuel ratio/lambda and the ignition advance for maximum brake torque (MBT), wide-open throttle (WOT)), and two torque loads for different engine speeds representative of typical driving. The additive incorporation up to 10% often improved efficiency and lowered emissions such as CO and HC relative to both straight gasolines, but NOx increased with the addition of a blend.

Two-Stroke Marine Diesel Engine Variable Injection Timing System Performance Evaluation and Optimum Setting for Minimum Fuel Consumption at Acceptable NOx Levels

2014 ◽  
Author(s):  
Dimitrios T. Hountalas ◽  
Spiridon Raptotasios ◽  
Antonis Antonopoulos ◽  
Stavros Daniolos ◽  
Iosif Dolaptzis ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Engine Performance ◽  
Operating Conditions ◽  
Specific Fuel Consumption ◽  
Injection Timing ◽  
Nox Emissions ◽  
Pressure Measurements ◽  
Cylinder Pressure ◽  
Start Of Injection

Currently the most promising solution for marine propulsion is the two-stroke low-speed diesel engine. Start of Injection (SOI) is of significant importance for these engines due to its effect on firing pressure and specific fuel consumption. Therefore these engines are usually equipped with Variable Injection Timing (VIT) systems for variation of SOI with load. Proper operation of these systems is essential for both safe engine operation and performance since they are also used to control peak firing pressure. However, it is rather difficult to evaluate the operation of VIT system and determine the required rack settings for a specific SOI angle without using experimental techniques, which are extremely expensive and time consuming. For this reason in the present work it is examined the use of on-board monitoring and diagnosis techniques to overcome this difficulty. The application is conducted on a commercial vessel equipped with a two-stroke engine from which cylinder pressure measurements were acquired. From the processing of measurements acquired at various operating conditions it is determined the relation between VIT rack position and start of injection angle. This is used to evaluate the VIT system condition and determine the required settings to achieve the desired SOI angle. After VIT system tuning, new measurements were acquired from the processing of which results were derived for various operating parameters, i.e. brake power, specific fuel consumption, heat release rate, start of combustion etc. From the comparative evaluation of results before and after VIT adjustment it is revealed an improvement of specific fuel consumption while firing pressure remains within limits. It is thus revealed that the proposed method has the potential to overcome the disadvantages of purely experimental trial and error methods and that its use can result to fuel saving with minimum effort and time. To evaluate the corresponding effect on NOx emissions, as required by Marpol Annex-VI regulation a theoretical investigation is conducted using a multi-zone combustion model. Shop-test and NOx-file data are used to evaluate its ability to predict engine performance and NOx emissions before conducting the investigation. Moreover, the results derived from the on-board cylinder pressure measurements, after VIT system tuning, are used to evaluate the model’s ability to predict the effect of SOI variation on engine performance. Then the simulation model is applied to estimate the impact of SOI advance on NOx emissions. As revealed NOx emissions remain within limits despite the SOI variation (increase).

Characteristics of Water-in-Diesel Emulsions in a Single Cylinder Compression Ignition Engine

2014 ◽  
Author(s):  
Teja Gonguntla ◽  
Robert Raine ◽  
Leigh Ramsey ◽  
Thomas Houlihan
Keyword(s):  
Fuel Consumption ◽  
Direct Injection ◽  
Engine Performance ◽  
Operating Conditions ◽  
Specific Fuel Consumption ◽  
Brake Specific Fuel Consumption ◽  
Compression Ignition Engine ◽  
Oil Emulsion ◽  
Single Cylinder ◽  
Performance And Emission

The objective of this project was to develop both engine performance and emission profiles for two test fuels — a 6% water-in-diesel oil emulsion (DOE-6) fuel and a neat diesel (D100) fuel. The testing was performed on a single cylinder, direct-injection, water-cooled diesel engine coupled to an eddy current dynamometer. Output parameters of the engine were used to calculate Brake Specific Fuel Consumption (BSFC) and Engine Efficiency (η) for each test fuel. DOE-6 fuels generated a 24% reduction in NOX and a 42% reduction in Carbon Monoxide emissions over the tested operating conditions. DOE-6 fuels presented higher ignition delays — between 1°-4°, yielded 1%–12% lower peak cylinder pressures and produced up to 5.5% lower exhaust temperatures. Brake Specific Fuel consumption increased by 6.6% for the DOE-6 fuels as compared to the D100 fuels. This project is the first research done by a New Zealand academic institution on water-in-diesel emulsion fuels.

scholarly journals Neural Nonlinear Autoregressive Model with Exogenous Input (NARX) for Turboshaft Aeroengine Fuel Control Unit Model

Aerospace ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 206
Author(s):  
Maria Grazia De Giorgi ◽  
Luciano Strafella ◽  
Antonio Ficarella
Keyword(s):  
Neural Networks ◽  
Control System ◽  
Fuel Consumption ◽  
Control Method ◽  
Engine Performance ◽  
Control Unit ◽  
Specific Fuel Consumption ◽  
Engine Fuel ◽  
State Variables ◽  
Nonlinear Autoregressive

One of the most important parts of a turboshaft engine, which has a direct impact on the performance of the engine and, as a result, on the performance of the propulsion system, is the engine fuel control system. The traditional engine control system is a sensor-based control method, which uses measurable parameters to control engine performance. In this context, engine component degradation leads to a change in the relationship between the measurable parameters and the engine performance parameters, and thus an increase of control errors. In this work, a nonlinear model predictive control method for turboshaft direct fuel control is implemented to improve engine response ability also in presence of degraded conditions. The control objective of the proposed model is the prediction of the specific fuel consumption directly instead of the measurable parameters. In this way is possible decentralize controller functions and realize an intelligent engine with the development of a distributed control system. Artificial Neural Networks (ANN) are widely used as data-driven models for modelling of complex systems such as aeroengine performance. In this paper, two Nonlinear Autoregressive Neural Networks have been trained to predict the specific fuel consumption for several transient flight maneuvers. The data used for the ANN predictions have been estimated through the Gas Turbine Simulation Program. In particular the first ANN predicts the state variables based on flight conditions and the second one predicts the performance parameter based on the previous predicted variables. The results show a good approximation of the studied variables also in degraded conditions.

Turbocharged spark-ignition engine performance prediction in various inlet charged air temperatures fueled with gasoline–ethanol blends

2020 ◽  
pp. 146808742093171
Author(s):  
Reza Farzam ◽  
Bahram Jafari ◽  
Fateme Kalaki
Keyword(s):  
Fuel Consumption ◽  
Air Temperature ◽  
Thermal Efficiency ◽  
Engine Performance ◽  
Spark Ignition Engine ◽  
Specific Fuel Consumption ◽  
Brake Specific Fuel Consumption ◽  
Brake Torque ◽  
Combustion Duration ◽  
And Performance

In this research, the effect of alternative fuels and the inlet charged air temperature is numerically investigated on the performance of a turbocharged spark-ignition engine. For this purpose, a one-dimensional engine and turbocharger model is created in an engine simulation and performance analysis software and validated with former experimental results. Then, the model is run with four fuel types, including two gasoline types with different octane numbers and two ethanol–gasoline blend fuels—E25 and E85. In each case, the inlet charged air temperature is changed from cold to hot condition and performance characteristics such as the spark advance timing, brake torque, brake-specific fuel consumption and thermal efficiency, emissions and the ignition delay and combustion duration are obtained from simulation results. The results illustrate that by decreasing the inlet charged air temperature, the spark timing is more advanced due to less knock and the brake torque increases. Also, the brake-specific fuel consumption and the brake NOx and CO2 decrease and thermal efficiency increases in all fuel types. The results also demonstrate that in higher ethanol percent in blend fuels, all engine performance characteristics improve except brake-specific fuel consumption; as changing the fuel at constant fuel-to-air equivalence ratio from E25 to E85 in various revolutions per minute causes a 5.8% increase in the brake torque, 1.06% increase in the thermal efficiency, 43% and 3.9% decrease in the brake NOx and CO2 and 5.8 °CA decrease in the combustion duration, on average; while the brake-specific fuel consumption and the peak pressure increase 29% and 20%, respectively.

Effect of Stationary Natural Gas Engine Oils on Fuel Economy

2012 ◽  
Author(s):  
Nikhil Dayanand ◽  
John D. Palazzotto ◽  
Alan T. Beckman
Keyword(s):  
Natural Gas ◽  
Fuel Consumption ◽  
Fuel Economy ◽  
Operating Conditions ◽  
Specific Fuel Consumption ◽  
Engine Oil ◽  
Brake Specific Fuel Consumption ◽  
Oil Viscosity ◽  
Gas Engine ◽  
Natural Gas Engine

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.

scholarly journals Impact of Compressed Natural Gas (CNG) Fuel Systems in Small Engine Wood Chippers on Exhaust Emissions and Fuel Consumption

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6709
Author(s):  
Łukasz Warguła ◽  
Mateusz Kukla ◽  
Piotr Lijewski ◽  
Michał Dobrzyński ◽  
Filip Markiewicz
Keyword(s):  
Natural Gas ◽  
Fuel Consumption ◽  
Average Power ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Maximum Diameter ◽  
Nox Emissions ◽  
Compressed Natural Gas ◽  
Hc Emissions

The projected increase in the availability of gaseous fuels by growing popularity of household natural gas (NG) filling stations and the increase in the production of gaseous biogas-derived fuels is conducive to an increase in the use of NG fuel. Currently, natural gas in various forms (compressed natural gas (CNG), liquefied natural gas (LNG)) is popular in maritime, rail and road transport. A new direction of natural gas application may be non-road mobile machines powered by a small spark-ignition engine (SI). The use of these engines in the wood chippers can cause the reduction of machine costs and emissions of harmful exhaust gases. In addition, plant material chippers intended for composting in bio-gas plants can be driven by the gas they are used to produce. The biogas can be purified to bio-methane to meet natural gas quality standards. The article presents the design of the natural gas supply system, which is an upgrade of the Lifan GX 390 combustion engine spark ignition engine (Four-stroke, OHV (over head valve) with a maximum power of 9.56 kW), which is a common representative of small gasoline engines. The engine is mounted in a cylindrical chipper designed for shredding branches with a maximum diameter of up to 100 mm, which is a typical machine used for cleaning work in urban areas. The engine powered by CNG and traditionally gasoline has been tested in real working conditions, when shredding cherry plum (Prunus cerasifera Ehrh. Beitr. Naturk. 4:17. 1789 (Gartenkalender4:189–204. 1784)). Their diameter was ca. 80 mm, 3-metere-long, and humidity content ca. 25%. The systems were tested under the same actual operating conditions, the average power generated by the drives during shredding is about 0.69 kW. Based on the recorded results, it was found that the CNG-fuelled engine was characterized by nitrogen oxides (NOx) emissions higher by 45%. The other effects of CNG were a reduction in carbon dioxide (CO2), carbon monoxide (CO) and hydrocarbon (HC) emissions of about 81%, 26% and 57%, respectively. Additionally, the use of CNG reduced fuel consumption by 31% and hourly estimated machine operating costs resulting from fuel costs by 53% (for average fuel price in Poland: gasoline: 0.99 EUR/L and CNG: 0.71 EUR/m3 on 08 November 2020). The modernization performed by the authors ensured the work of the drive unit during shredding, closer to the value of stoichiometric mixtures. The average (AVG) value of the air fuel ratio (AFR) for CNG was enriched by 1.2% (AVG AFR was 17), while for the gasoline engine the mixture was more enriched by 4.8% (AVG AFR was 14). The operation of spark-ignition (SI) combustion engines is most advantageous when burning stoichiometric mixtures due to the cooperation with exhaust aftertreatment systems (e.g., three-function catalytic converter). A system powered by CNG may be beneficial in systems adapting to operating conditions, used in low-power shredding machines, whose problem is increased HC emissions, and CNG combustion may reduce them. The developed system does not exceed the emission standards applicable in the European Union. For CO emissions expressed in g/kWh, it was about 95% lower than the permissible value, and HC + NOx emissions were 85% lower. This suggests that the use of the fuel in question may contribute to tightening up the permissible emission regulations for non-road machinery.

A comparative study of the performance and exhaust emissions of a spark ignition engine fuelled by natural gas and gasoline

1997 ◽  
Vol 211 (1) ◽  
pp. 39-47 ◽  
Author(s):  
R. L. Evans ◽  
J Blaszczyk
Keyword(s):  
Natural Gas ◽  
Engine Performance ◽  
Detailed Comparison ◽  
Exhaust Emissions ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Spark Ignition Engines ◽  
Wide Range ◽  
Lean Limit

The purpose of this study was to obtain a detailed comparison of engine performance and exhaust emissions from natural gas and gasoline fuelled spark ignition engines. Each fuel was tested at both wide-open throttle and two part-load operating conditions over a wide range of air—fuel ratios. The results show that the power output of the engine at a given throttle position was reduced by about 12 per cent when fuelled by natural gas due to displacement of air by the gas. The emission levels for natural gas were lower by from 5 to 50 per cent, depending on the pollutant, compared to gasoline. On an energy basis, both fuels exhibited nearly equal thermal efficiency, except that at very lean air—fuel ratios natural gas showed increased efficiency due to an extension of the lean limit of combustion.

Improvement of Engine Performance Using an Adaptive Valve Lift and Timing (AVLT) Mechanism at High Engine Speeds

2014 ◽  
Vol 663 ◽  
pp. 359-365
Author(s):  
A.F. Abdul Rasid ◽  
T.I. Mohamad ◽  
M.J. Ghazali ◽  
W.M.F. Wan Mahmood
Keyword(s):  
Engine Speed ◽  
Electronic Control Unit ◽  
Engine Performance ◽  
Control Unit ◽  
Hydraulic Cylinder ◽  
Spark Ignition Engine ◽  
Valve Lift ◽  
Feedback Signal ◽  
Engine Model ◽  
High Engine Speed

This paper explains about an improvement of high end performance using an adaptive valve lift and timing mechanism (AVLT). This system is developed with an aim to produce a more powerful engine through a variable valve timing technique. The preliminary design of this system adjusts the valve lift via control lever positioned by the rotation of an electric motor and has the potential to be actuated by a hydraulic cylinder that utilises engine fluids pressure difference with respect to the engine speed which made the valve lifts higher in higher engine speed and loads. The mechanism actuation is determined by a feedback signal of the engine electronic control unit that interacted in relation with the present engine speed and load. Therefore, a continuously dynamic valve lift profile with respect to the engine speed can be achieved thus varies the output performance of an engine. As a result of applying the AVLT on a simulated engine model with the actual parameters, the power and torque were increased in high engine speed (above 4000 rpm). The AVLT is able to increase the default valve lift by up to 35.96%. In high end speed of 7000 rpm, maximum lift of AVLT improved engine power by 4.26%, brake torque by 4.25% and reduced the brake specific fuel consumption by 1.14%. Maximum lift of AVLT increased the engine peak power at 6000 rpm by 2.38%. The product of this research will be useful to optimise the height of the valve lift during operation thus improves the engine performance, fuel economy and emission levels of spark ignition engine.

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