scholarly journals A Comparative Study on Influence of Natural Gas Composition on the Performance of a CNG Engine

2018 ◽  
Vol 2 (3) ◽  
pp. 9-18 ◽  
Author(s):  
Amirhasan Kakaee ◽  
Majid Karimi
Keyword(s):  
Natural Gas ◽  
Internal Combustion Engines ◽  
Engine Performance ◽  
Practical Method ◽  
High Energy ◽  
Gas Composition ◽  
Natural Gases ◽  
Operation Conditions ◽  
Cng Engine ◽  
Engine Power

Natural gas is the cleanest fossil fuel and it has high energy conversion efficiencies for power generation in internal combustion engines. Natural gases have varying composition depending on the place where they are produced. This paper studies the effects of natural gas composition on the combustion and emissions characteristics of CNG engines and presents the overall combustion characteristics obtained from running a 1.65 L, 4-cylinder EF 7 CNG engine. Engine power, Torque, BMEP and BSFC were measured under steady state operation conditions at full load conditions. The obtained simulation results were compared with experimental ones in the literature and showed that the CNG composition had a considerable influence on engine performance and fuel economy. A correlation has been proposed to help gain insight into the relationship between the Methane Number (MN) and engine power, and it provides a practical method for estimating the engine power when the composition of natural gases varies.

Carbonyl Compounds and PAH Emissions From CNG Heavy-Duty Engine

1993 ◽  
Vol 115 (4) ◽  
pp. 747-749 ◽  
Author(s):  
M. Gambino ◽  
R. Cericola ◽  
P. Corbo ◽  
S. Iannaccone
Keyword(s):  
Diesel Engine ◽  
Natural Gas ◽  
Carbonyl Compounds ◽  
Internal Combustion Engines ◽  
Engine Performance ◽  
Formaldehyde Emission ◽  
Pollutant Emissions ◽  
Heavy Duty ◽  
Test Analysis ◽  
Cng Engine

Previous works carried out in Istituto Motori laboratories have shown that natural gas is a suitable fuel for general means of transportation. This is because of its favorable effects on engine performance and pollutant emissions. The natural gas fueled engine provided the same performance as the diesel engine, met R49 emission standards, and showed very low smoke levels. On the other hand, it is well known that internal combustion engines emit some components that are harmful for human health, such as carbonyl compounds and polycyclic aromatic hydrocarbons (PAH). This paper shows the results of carbonyl compounds and PAH emissions analysis for a heavy-duty Otto cycle engine fueled with natural gas. The engine was tested using the R49 cycle that is used to measure the regulated emissions. The test analysis has been compared with an analysis of a diesel engine, tested under the same conditions. Total PAH emissions from the CNG engine were about three orders of magnitude lower than from the diesel engine. Formaldehyde emission from the CNG engine was about ten times as much as from the diesel engine, while emissions of other carbonyl compounds were comparable.

Investigating realistic anode off-gas combustion in SOFC/ICE hybrid systems: mini review and experimental evaluation

2021 ◽  
pp. 146808742110583
Author(s):  
Ioannis Nikiforakis ◽  
Zhongnan Ran ◽  
Michael Sprengel ◽  
John Brackett ◽  
Guy Babbit ◽  
...  
Keyword(s):  
Thermal Efficiency ◽  
Internal Combustion Engines ◽  
Engine Performance ◽  
High Energy ◽  
Operating Conditions ◽  
Compression Ignition ◽  
Case Scenario ◽  
Gas Combustion ◽  
Thermodynamic Conditions ◽  
Decentralized Energy

Solid oxide fuel cells (SOFCs) have been deployed in hybrid decentralized energy systems, in which they are directly coupled to internal combustion engines (ICEs). Prior research indicated that the anode tailgas exiting the SOFC stack should be additionally exploited due to its high energy value, with typical ICE operation favoring hybridization due to matching thermodynamic conditions during operation. Consequently, extensive research has been performed, in which engines are positioned downstream the SOFC subsystem, operating in several modes of combustion, with the most prevalent being homogeneous compression ignition (HCCI) and spark ignition (SI). Experiments were performed in a 3-cylinder ICE operating in the latter modus operandi, where the anode tailgas was assimilated by mixing syngas (H2: 33.9%, CO: 15.6%, CO2: 50.5%) with three different water vapor flowrates in the engine’s intake. While increased vapor content significantly undermined engine performance, brake thermal efficiency (BTE) surpassed 34% in the best case scenario, which outperformed the majority of engines operating under similar operating conditions, as determined from the conducted literature review. Nevertheless, the best performing application was identified operating under HCCI, in which diesel reformates assimilating SOFC anode tailgas, fueled a heavy duty ICE (17:1), and gross indicated thermal efficiency ([Formula: see text]) of 48.8% was achieved, with the same engine exhibiting identical performance when operating in reactivity-controlled compression ignition (RCCI). Overall, emissions in terms of NOx and CO were minimal, especially in SI engines, while unburned hydrocarbons (UHC) were non-existent due to the absence of hydrocarbons in the assessed reformates.

Comparison of Random Forest and Neural Network in Modelling the Performance and Emissions of a Natural Gas Spark Ignition Engine

2021 ◽  
pp. 1-20
Author(s):  
Jinlong Liu ◽  
Qiao Huang ◽  
Christopher Ulishney ◽  
Cosmin E. Dumitrescu
Keyword(s):  
Neural Network ◽  
Random Forest ◽  
Natural Gas ◽  
Internal Combustion Engines ◽  
Engine Performance ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Data Driven ◽  
Ann Model ◽  
Mean Square Errors

Abstract Machine learning (ML) models can accelerate the development of efficient internal combustion engines. This study assessed the feasibility of data-driven methods towards predicting the performance of a diesel engine modified to natural gas spark ignition, based on a limited number of experiments. As the best ML technique cannot be chosen a priori, the applicability of different ML algorithms for such an engine application was evaluated. Specifically, the performance of two widely used ML algorithms, the random forest (RF) and the artificial neural network (ANN), in forecasting engine responses related to in-cylinder combustion phenomena was compared. The results indicated that both algorithms with spark timing, mixture equivalence ratio, and engine speed as model inputs produced acceptable results with respect to predicting engine performance, combustion phasing, and engine-out emissions. Despite requiring more effort in hyperparameter optimization, the ANN model performed better than the RF model, especially for engine emissions, as evidenced by the larger R-squared, smaller root-mean-square errors, and more realistic predictions of the effects of key engine control variables on the engine performance. However, in applications where the combustion behavior knowledge is limited, it is recommended to use a RF model to quickly determine the appropriate number of model inputs. Consequently, using the RF model to define the model structure and then employing the ANN model to improve the model's predictive capability can help to rapidly build data-driven engine combustion models.

scholarly journals Effect of Natural Gas Composition on the Performance of a CNG Engine

2008 ◽  
Vol 64 (2) ◽  
pp. 199-206 ◽  
Author(s):  
K. Kim ◽  
H. Kim ◽  
B. Kim ◽  
K. Lee ◽  
K. Lee
Keyword(s):  
Natural Gas ◽  
Gas Composition ◽  
Cng Engine

scholarly journals Control-oriented analysis of a lean-burn light-duty natural gas research engine with scavenged pre-chamber ignition

2019 ◽  
Vol 176 (1) ◽  
pp. 42-53
Author(s):  
Severin HÄNGGI ◽  
Thomas HILFIKER ◽  
Patrik SOLTIC ◽  
Richard HUTTER ◽  
Christopher ONDER
Keyword(s):  
Natural Gas ◽  
Control Structure ◽  
Engine Performance ◽  
Combustion Stability ◽  
Performance Criteria ◽  
Transport Sector ◽  
Lean Burn ◽  
Fuel Ratio ◽  
Cng Engine ◽  
Lean Conditions

Natural gas is well-suited as a fuel in the transport sector. Due to its excellent combustion characteristics, engines operating with compressed natural gas (CNG) reach high efficiency, especially if operated at lean conditions. However, CNG engine research mainly focusses on stoichiometric conditions in order to use a three-way catalytic converter for the exhaust gas after treatment system. With the objective to explore the potential of CNG engines operated at lean conditions, a turbo-charged CNG engine with high com-pression ratio is developed and optimized for lean operation. In order to increase the ignition energy, the CNG engine is equipped with scavenged pre-chambers. A specific control structure is developed, which allows to operate the engine at a pre-defined (lean) air-to-fuel ratio. Further functionalities such as the combustion placement control and algorithms to estimate the conditions inside of the pre-chamber are implemented. The first part of this paper describes this engine control structure, which is specifically developed for the lean-burn CNG engine. In the second part, the effects of pre-chamber scavenging on engine performance criteria such as the combustion stability, engine efficiency or engine emissions are analyzed. With the objective to use pre-chamber scavenging to improve engine performance, a scavenging feed-back control strategy is proposed. In order to control the ignition delay, this strategy adapts the amount of CNG injected into the pre-chamber with a linear controller or an extremum seeking algorithm depending on the air-to-fuel ratio of the main chamber.

Improved Thermodynamic Model for Lean Natural Gas Spark Ignition in a Diesel Engine Using a Triple Wiebe Function

2019 ◽  
Vol 142 (6) ◽  
Author(s):  
Jinlong Liu ◽  
Cosmin Emil Dumitrescu
Keyword(s):  
Natural Gas ◽  
Diesel Engines ◽  
Mass Fraction ◽  
Internal Combustion Engines ◽  
Combustion Process ◽  
Spark Ignition ◽  
High Energy ◽  
Multi Stage ◽  
Stage Combustion ◽  
Wiebe Function

Abstract The use of natural gas (NG) in heavy-duty internal combustion engines can reduce the dependence on petroleum fuels and greenhouse gas emissions. Diesel engines can convert to NG spark ignition (SI) by installing a high-energy ignition system and a gas injector. The diesel combustion chamber affects the flow inside the cylinder, so some existing SI combustion models will not accurately describe the operation of converted diesels. For example, the single Wiebe function has difficulties in correctly describing the mass fraction burn (MFB) throughout the combustion process. This study used experiments from a 2L single-cylinder research engine converted to port fuel injection NG SI and operated with methane at 1300 rpm and equivalence ratio 0.8 (6.2 bars IMEP) to compare the standard Wiebe function with a triple Wiebe function. Results indicated that lean-burn engine operation at an advanced spark timing produced three peaks in the heat release rate, suggesting a multi-stage combustion process. A “best goodness-of-fit” approach determined the values of the key parameters in the zero-dimensional Wiebe function model. The triple Wiebe function described the mass fraction burn and combustion phasing more accurately compared with the single Wiebe function. Moreover, it provided the duration and phasing of each individual burning stage that can then characterize the combustion in such converted diesel engines. This suggests that a multiple Wiebe function combustion model would effectively assist in analyzing such a multi-stage combustion process, which is important for engine optimization and development.

scholarly journals Lean-burn CNG engine with ignition chamber: from the idea to a running engine

2019 ◽  
Vol 176 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Michael WEIßNER ◽  
Frank BEGER ◽  
Martin SCHÜTTENHELM ◽  
Gunesh TALLU
Keyword(s):  
Natural Gas ◽  
Internal Combustion Engines ◽  
State Of The Art ◽  
Combustion Engines ◽  
Lean Burn ◽  
Compressed Natural Gas ◽  
Emission Regulations ◽  
Cng Engine ◽  
Funded Project ◽  
The Eu

Current and further developing CO2- and emission regulations worldwide and the competition to full electric mobility deliver a chal-lenge for internal combustion engines in general. A state of the art solution is the use of natural gas mainly contending methane to reduce CO2 significantly and to offer lowest emission levels. The EU-funded project GasOn developed engine concepts to fully exploit the advantages of CNG. This article describes the development of an innovative, monovalent engine dedicated to Compressed Natural Gas (CNG) and characterised by the lean burn concept and the innovative pre-chamber combustion.

Metastability of Natural Gas Hydrates in the Presence of N2 and H2S

2004 ◽  
Vol 126 (2) ◽  
pp. 125-132 ◽  
Author(s):  
Jan Lubas´ ◽  
Barbara Darłak
Keyword(s):  
Natural Gas ◽  
Hydrogen Sulphide ◽  
Gas Hydrates ◽  
Laboratory Experiments ◽  
Gas Composition ◽  
Natural Gases ◽  
Natural Gas Hydrates ◽  
The Relationship

The paper presents the results of laboratory experiments on formation and dissociation of hydrates of natural gases containing nitrogen and hydrogen sulphide. The hydrate metastability region and subcooling temperatures were measured and analyzed. The relationship between the gas composition and temperature of subcooling is investigated.

CHARACTERIZATION OF PERODUA MYVI K3-VE I4 ENGINE PERFORMANCE USING EXHAUST GAS RECIRCULATION (EGR)

2015 ◽  
Vol 75 (8) ◽  
Author(s):  
M. Hanif Mat Muhammad ◽  
A. Qaiyum Hanafiah ◽  
Aman Mohd Ihsan Mamat
Keyword(s):  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Nox Reduction ◽  
Engine Performance ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Emission Regulations ◽  
Current Emission ◽  
Gas Recirculation ◽  
Engine Power

Internal combustion engines are the main power source for  automobile vehicles.  As current  emission regulations becomes more stringent, more fuel efficient and less polluting engines are becoming the focus of car manufacturers. This paper presents the study of improving the performance of K3-VE I4 internal combustion engine that is used in the Perodua Myvi for the Perodua Eco-Challenge 2013. The strategy was  to use an EGR system to reduce Brake Specific Fuel Consumption (BSFC) while maintaining or increasing the engine power. The effects of different location of EGR on the engine performance were tested on a chassis dynamometer. The sensitivity of the engine performance and gas emission were studied since EGR implementation plays a  major role in influencing NOx emission. The performance parameter such as engine power and BSFC were then analysed. The result shows that a significant increase of power can be achieved and a reduction of around 56% was obtained on the BSFC. While the best NOx reduction was around 93%. These improvements are obtained at low RPM that corresponds to Perodua Eco-Challenge’s objective.  

An Experimental Study of the Combustion Process in a Natural-Gas Spark-Ignition Engine

2019 ◽  
Author(s):  
Jinlong Liu ◽  
Cosmin E. Dumitrescu ◽  
Hemanth Bommisetty
Keyword(s):  
Natural Gas ◽  
Equivalence Ratio ◽  
Internal Combustion Engines ◽  
Combustion Process ◽  
Spark Ignition ◽  
High Energy ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Intake Manifold ◽  
Spark Timing

Abstract The conversion of existing internal combustion engines to natural-gas operation can reduce U.S. dependence on petroleum imports and curtail engine-out emissions. In this study, a diesel engine with a 13.3 compression ratio was modified to natural-gas spark-ignited operation by replacing the original diesel injector with a high-energy spark plug and by fumigating fuel inside the intake manifold. The goal of this research was to investigate the combustion process inside the flat-head and bowl-in-piston chamber of such retrofitted engine when operated at different spark timings, mixture equivalence ratios, and engine speeds. The results indicated that advanced spark timing, a lower equivalence ratio, and a higher speed operation increased the ignition lag and made it more difficult to initiate the combustion process. Further, advanced spark timing, a larger equivalence ratio, and a lower speed operation accelerated the flame propagation process inside the piston bowl and advanced the start of the burn inside the squish. However, such conditions increased the burning duration inside the squish due to more fuel being trapped inside the squish volume and the smaller squish height during combustion. As a result, the end of combustion was almost the same despite the change in the operating conditions. In addition, the reliable ignition, stable combustion, and the lack of knocking showed promise for the application of natural-gas lean-burn spark-ignition operation in the heavy-duty transportation.

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