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.

Experimental Study of the Effects of Thermal Coating and Oxygenated Additives on Diesel Engine Performance and Pollutant Emissions

2008 ◽  
Author(s):  
P. Ramu ◽  
C. G. Saravanan
Keyword(s):  
Diesel Engine ◽  
Internal Combustion Engines ◽  
Cooling System ◽  
Engine Performance ◽  
Plasma Coating ◽  
Nox Emission ◽  
Pollutant Emissions ◽  
Exhaust Emission ◽  
Fuel Additive ◽  
Oxygenated Additives

In internal combustion engines, approximately one third of the total fuel input energy was converted into useful work and two-third has loss through exhaust gas and cooling system. Recently research has been focused on the reduction of diesel emitted pollutants due to strict emission regulations. In this study, the effect of ceramic coating to cylinder head, valves and piston crown on diesel engine performance and exhaust emission is examined. Ceramic layers were made by ZrO2-Al2O3 by using plasma coating method thickness to about 200 microns. The ceramic coated diesel engine was tested in a single cylinder, four stroke and water cooled DI diesel engine. Second part of the investigation was carried out with the fuel additive di iso propyl ether with thermal barrier coated diesel engine. The results indicate that there is reduction in fuel consumption, NOx emission and slightly increases the thermal efficiency of the engine. The combined effect of coating and fuel additive has significantly reduced the NOx emission.

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.

An Intake System Optimization of a Heavy Duty DI Diesel Engine Using CFD Analysis

2015 ◽  
Author(s):  
Kareem Emara ◽  
Ahmed Emara ◽  
Elsayed Abdel Razek
Keyword(s):  
Diesel Engine ◽  
Optimal Design ◽  
Internal Combustion Engines ◽  
Direct Injection ◽  
Engine Performance ◽  
System Optimization ◽  
Intake Manifold ◽  
Heavy Duty ◽  
Intake System ◽  
Di Diesel Engine

As the intake system design is significant for the optimal performance of internal combustion engines, this work aims to optimize the geometry of an intake system in a direct injection (DI) diesel engine. The study concerns the geometry effects of three different intake manifolds mounted consecutively on a fully instrumented, six cylinders, in line, water cooled, 19.1 liters displacement, DI heavy duty diesel engine. A 3D numerical simulation of the turbulent flow through these manifolds is applied. The model is based on solving Navier-Stokes and energy equations in conjunction with the standard K-ε turbulence model and hypothetical boundary conditions using ANSYS- CFX 15. Numerical results of this simulation are presented in the form of flow field velocity as well as pressure field. Optimal design of the intake system is performed and the modeling made it possible to provide a fine knowledge of in-flow structures, in order to examine the adequate manifold. Engine performance characteristics such as brake torque, brake power, thermal efficiency and specific fuel consumption are also carried out to evaluate the effects of the variation in the intake manifold geometry and to validate the optimal design. Simulation and experimental results confirmed the effectiveness of the optimized manifold geometry on the engine performances.

CFD Analysis and Experimental Investigation of a Heavy Duty D.I. Diesel Engine Exhaust System

2016 ◽  
Author(s):  
Kareem Emara ◽  
Ahmed Emara ◽  
Elsayed Abdel Razek
Keyword(s):  
Diesel Engine ◽  
Internal Combustion Engines ◽  
Direct Injection ◽  
Engine Performance ◽  
Exhaust System ◽  
Back Pressure ◽  
Optimized Design ◽  
Exhaust Manifold ◽  
Heavy Duty ◽  
Exhaust Gases

Exhaust manifold is one of the most critical components of an internal combustion engines and overall engine performance can be obtained from the proper optimized design of engine inlet and exhaust systems. In this study two exhaust system models with different configuration (the existing as base one and the modified one) are simulated using ANSYS-CFX 15 with the appropriate boundary conditions and fluid properties specified to the system with suitable assumptions. The model is based on solving NAVIERE STOKES and energy equations in conjunction with the standard K-ε turbulence model. The first design is a single pipe receives exhaust gases from all runners and delivers the exhaust gases to turbocharger inlet. But the second design consists of two tubes each of one receives the exhaust gases coming from the three cylinders only. This design makes the intensity of the exhaust pulses of high pressure, which leads to increase the speed of the turbocharger. The uniformity of the flow field and back pressure variations in the two models are discussed in. A decrease in backpressure and increase in velocities are shown using the pressure contour and the velocity contour in the exhaust manifold as well as temperature distribution inside the exhaust manifold system. The best design is also simulated at different engine speed. Finally the modified model with limited back pressure was fabricated and experiments are carried out on a fully instrumented six cylinder in line water cooled heavy duty direct injection diesel engine; (350 hp@2200 rpm and 1400 Nm@1350 rpm).The pressure and temperature are measured at definite points in the exhaust gas manifold. The results obtained by experimental work were compared with the analytic CFD and found to be closely matching with accepted error.

A phenomenological model for the description of unburned hydrocarbons emission in ultra-lean engines

2021 ◽  
pp. 146808742110050
Author(s):  
Enrica Malfi ◽  
Vincenzo De Bellis ◽  
Fabio Bozza ◽  
Alberto Cafari ◽  
Gennaro Caputo ◽  
...  
Keyword(s):  
Natural Gas ◽  
Internal Combustion Engines ◽  
Pollutant Emissions ◽  
Average Error ◽  
Combustion Engines ◽  
Nitric Oxides ◽  
Lean Burn ◽  
Fuel Charge ◽  
Unburned Hydrocarbons ◽  
Model Reliability

The adoption of lean-burn concepts for internal combustion engines working with a homogenous air/fuel charge is under development as a path to simultaneously improve thermal efficiency, fuel consumption, nitric oxides, and carbon monoxide emissions. This technology may lead to a relevant emission of unburned hydrocarbons (uHC) compared to a stoichiometric engine. The uHC sources are various and the relative importance varies according to fuel characteristics, engine operating point, and some geometrical details of the combustion chamber. This concern becomes even more relevant in the case of engines supplied with natural gas since the methane has a global warming potential much greater than the other major pollutant emissions. In this work, a simulation model describing the main mechanisms for uHC formation is proposed. The model describes uHC production from crevices and flame wall quenching, also considering the post-oxidation. The uHC model is implemented in commercial software (GT-Power) under the form of “user routine”. It is validated with reference to two large bore engines, whose bores are 31 and 46 cm (engines named accordingly W31 and W46). Both engines are fueled with natural gas and operated with lean mixtures (λ > 2), but with different ignition modalities (pre-chamber device or dual fuel mode). The engines under study are preliminarily schematized in the 1D simulation tool. The consistency of 1D engine schematizations is verified against the experimental data of BMEP, air flow rate, and turbocharger rotational speed over a load sweep. Then, the uHC model is validated against the engine-out measurements. The averaged uHC predictions highlight an average error of 7% and 10 % for W31 and W46 engines, respectively. The uHC model reliability is evidenced by the lack of need for a case-dependent adjustment of its tuning constants, also in presence of relevant variations of both engine load and ring pack design.

A phenomenological combustion analysis of a dual-fuel natural-gas diesel engine

2016 ◽  
Vol 231 (1) ◽  
pp. 66-83 ◽  
Author(s):  
Shuonan Xu ◽  
David Anderson ◽  
Mark Hoffman ◽  
Robert Prucka ◽  
Zoran Filipi
Keyword(s):  
Diesel Engine ◽  
Natural Gas ◽  
Heat Release ◽  
Diesel Fuel ◽  
Fuel Injection ◽  
Dual Fuel ◽  
Injection Timing ◽  
Heavy Duty ◽  
Engine System ◽  
Wiebe Function

Energy security concerns and an abundant supply of natural gas in the USA provide the impetus for engine designers to consider alternative gaseous fuels in the existing engines. The dual-fuel natural-gas diesel engine concept is attractive because of the minimal design changes, the ability to preserve a high compression ratio of the baseline diesel, and the lack of range anxiety. However, the increased complexity of a dual-fuel engine poses challenges, including the knock limit at a high load, the combustion instability at a low load, and the transient response of an engine with directly injected diesel fuel and port fuel injection of compressed natural gas upstream of the intake manifold. Predictive simulations of the complete engine system are an invaluable tool for investigations of these conditions and development of dual-fuel control strategies. This paper presents the development of a phenomenological combustion model of a heavy-duty dual-fuel engine, aided by insights from experimental data. Heat release analysis is carried out first, using the cylinder pressure data acquired with both diesel-only and dual-fuel (diesel and natural gas) combustion over a wide operating range. A diesel injection timing correlation based on the injector solenoid valve pulse widths is developed, enabling the diesel fuel start of injection to be detected without extra sensors on the fuel injection cam. The experimental heat release trends are obtained with a hybrid triple-Wiebe function for both diesel-only operation and dual-fuel operation. The ignition delay period of dual-fuel operation is examined and estimated with a predictive correlation using the concept of a pseudo-diesel equivalence ratio. A four-stage combustion mechanism is discussed, and it is shown that a triple-Wiebe function has the ability to represent all stages of dual-fuel combustion. This creates a critical building block for modeling a heavy-duty dual-fuel turbocharged engine system.

EGR cylinder deactivation strategy to accelerate the warm-up and restart processes in a Diesel engine operating at cold conditions

2021 ◽  
pp. 146808742110395
Author(s):  
José Galindo ◽  
Vicente Dolz ◽  
Javier Monsalve-Serrano ◽  
Miguel Angel Bernal Maldonado ◽  
Laurent Odillard
Keyword(s):  
Steady State ◽  
Diesel Engine ◽  
Internal Combustion Engines ◽  
Cold Start ◽  
Pollutant Emissions ◽  
Oxidation Catalyst ◽  
Maximum Efficiency ◽  
Warm Up ◽  
Cylinder Deactivation ◽  
The Impact

The aftertreatment systems used in internal combustion engines need high temperatures for reaching its maximum efficiency. By this reason, during the engine cold start period or engine restart operation, excessive pollutant emissions levels are emitted to the atmosphere. This paper evaluates the impact of using a new cylinder deactivation strategy on a Euro 6 turbocharged diesel engine running under cold conditions (−7°C) with the aim of improving the engine warm-up process. This strategy is evaluated in two parts. First, an experimental study is performed at 20°C to analyze the effect of the cylinder deactivation strategy at steady-state and during an engine cold start at 1500 rpm and constant load. In particular, the pumping losses, pollutant emissions levels and engine thermal efficiency are analyzed. In the second part, the engine behavior is analyzed at steady-state and transient conditions under very low ambient temperatures (−7°C). In these conditions, the results show an increase of the exhaust temperatures of around 100°C, which allows to reduce the diesel oxidation catalyst light-off by 250 s besides of reducing the engine warm-up process in approximately 120 s. This allows to reduce the CO and HC emissions by 70% and 50%, respectively, at the end of the test.

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