scholarly journals Structural characterisation of soot particles for cold-start and hot-start operation of a diesel engine

2020 ◽  
Author(s):  
Priyanka Arora ◽  
Faisal Lodi ◽  
Puneet Verma ◽  
Mohammad Jafari ◽  
Ali Zare ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Cold Start ◽  
Soot Particles ◽  
Structural Characterisation ◽  
Hot Start

scholarly journals Combustion Analysis of a Diesel Engine during Warm up at Different Coolant and Lubricating Oil Temperatures

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3931
Author(s):  
Faisal Lodi ◽  
Ali Zare ◽  
Priyanka Arora ◽  
Svetlana Stevanovic ◽  
Mohammad Jafari ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Ignition Delay ◽  
Peak Pressure ◽  
Cold Start ◽  
Lubricating Oil ◽  
Combustion Model ◽  
Injection Timing ◽  
Warm Up ◽  
Combustion Duration ◽  
Hot Start

A comprehensive analysis of combustion behaviour during cold, intermediately cold, warm and hot start stages of a diesel engine are presented. Experiments were conducted at 1500 rpm and 2000 rpm, and the discretisation of engine warm up into stages was facilitated by designing a custom drive cycle. Advanced injection timing, observed during the cold start period, led to longer ignition delay, shorter combustion duration, higher peak pressure and a higher peak apparent heat release rate (AHRR). The peak pressure was ~30% and 20% and the AHRR was ~2 to 5% and ±1% higher at 1500 rpm and 2000 rpm, respectively, during cold start, compared to the intermediate cold start. A retarded injection strategy during the intermediate cold start phase led to shorter ignition delay, longer combustion duration, lower peak pressure and lower peak AHRR. At 2000 rpm, an exceptional combustion behaviour led to a ~27% reduction in the AHRR at 25% load. Longer ignition delays and shorter combustion durations at 25% load were observed during the intermediately cold, warm and hot start segments. The mass fraction burned (MFB) was calculated using a single zone combustion model to analyse combustion parameters such as crank angle (CA) at 50% MFB, AHRR@CA50 and CA duration for 10–90% MFB.

scholarly journals Engine Performance and Emissions Analysis in a Cold, Intermediate and Hot Start Diesel Engine

2020 ◽  
Vol 10 (11) ◽  
pp. 3839 ◽  
Author(s):  
Faisal Lodi ◽  
Ali Zare ◽  
Priyanka Arora ◽  
Svetlana Stevanovic ◽  
Mohammad Jafari ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Cold Start ◽  
Lubricating Oil ◽  
Coolant Temperature ◽  
Effective Pressure ◽  
Warm Up ◽  
Hot Start ◽  
Depth Analysis ◽  
Performance And Emissions ◽  
The Impact

Presented in this paper is an in-depth analysis of the impact of engine start during various stages of engine warm up (cold, intermediate, and hot start stages) on the performance and emissions of a heavy-duty diesel engine. The experiments were performed at constant engine speeds of 1500 and 2000 rpm on a custom designed drive cycle. The intermediate start stage was found to be longer than the cold start stage. The oil warm up lagged the coolant warm up by approximately 10 °C. During the cold start stage, as the coolant temperature increased from ~25 to 60 °C, the brake specific fuel consumption (BSFC) decreased by approximately 2% to 10%. In the intermediate start stage, as the coolant temperature reached 70 °C and the injection retarded, the indicated mean effective pressure (IMEP) and the brake mean effective pressure (BMEP) decreased by approximately 2% to 3%, while the friction mean effective pressure (FMEP) decreased by approximately 60%. In this stage, the NOx emissions decreased by approximately 25% to 45%, while the HC emissions increased by approximately 12% to 18%. The normalised FMEP showed that higher energy losses at lower loads were most likely contributing to the heating of the lubricating oil.

scholarly journals Diesel engine emissions with oxygenated fuels: A comparative study into cold-start and hot-start operation

2017 ◽  
Vol 162 ◽  
pp. 997-1008 ◽  
Author(s):  
Ali Zare ◽  
Md Nurun Nabi ◽  
Timothy A. Bodisco ◽  
Farhad M. Hossain ◽  
M.M. Rahman ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Comparative Study ◽  
Cold Start ◽  
Engine Emissions ◽  
Diesel Engine Emissions ◽  
Hot Start ◽  
Oxygenated Fuels

scholarly journals Morphology and size of the particles emitted from a GDI-engine vehicle and their ageing in an environmental chamber

2019 ◽  
Author(s):  
Jiaoping Xing ◽  
Longyi Shao ◽  
Wenbin Zhang ◽  
Jianfei Peng ◽  
Wenhua Wang ◽  
...  
Keyword(s):  
Urban Environment ◽  
Research Programme ◽  
Cold Start ◽  
Gasoline Direct Injection ◽  
Photochemical Oxidation ◽  
Environmental Chamber ◽  
Soot Particles ◽  
Hot Start ◽  
Gdi Engine ◽  
Organic Particles

Abstract. Air pollution is particularly severe in developing megacities, such as Beijing, where pollutants from vehicles equipped with modern gasoline direct injection (GDI) engines must be paid enough attention. This study presents the characteristics of individual particles emitted by a GDI gasoline vehicle and their ageing in a smog chamber under the Beijing urban environment, as part of the Atmospheric Pollution & Human Health (APHH) research programme. Using electron microscopy, we identified the particles emitted from a commercial GDI-engine vehicle running under various conditions, namely cold start, hot start, hot stabilized running, idle, and acceleration states. Our results show that most of the particles were organic, soot and Ca-rich ones, with small quantities of S-rich and metal-containing particles. In terms of grain size, the particles exhibited a bimodal distribution in number vs size, with one mode at 800–900 nm, and the other at 140–240 nm. The amounts of organic particles emitted under hot start and hot stabilized states were higher than those emitted under other conditions. The amount of soot particles was higher under cold start and acceleration states. Under the idle state, the proportion of Ca-rich particles was highest, although their absolute number was low. In addition to quantifying the types of particles emitted by the engine, we studied the ageing of the particles during 3.5 hours of photochemical oxidation in an environmental chamber under the Beijing urban environment. Ageing transformed soot particles into core-shell structures, coated by secondary organic species, while the content of sulfur in Ca-rich and organic particles increased. Overall, the majority of particles from GDI-engine vehicles are organic and soot particles with submicron or nanometric size. The particles are highly reactive; they react in the atmosphere and change their morphology and composition within hours via catalyzed acidification that involves gaseous pollutants under high pollution levels in Beijing.

Predicted Paths of Soot Particles in the Cylinders of a Direct Injection Diesel Engine

2012 ◽  
Author(s):  
Wan Mohd Faizal Wan Mahmood ◽  
Antonino LaRocca ◽  
Paul J. Shayler ◽  
Fabrizio Bonatesta ◽  
Ian Pegg
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Soot Particles ◽  
Direct Injection Diesel Engine

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.

scholarly journals Magnetically induced termination of giant planet formation

2018 ◽  
Vol 619 ◽  
pp. A165 ◽  
Author(s):  
A. J. Cridland
Keyword(s):  
Magnetic Field ◽  
Cross Section ◽  
Planet Formation ◽  
Giant Planet ◽  
Effective Cross Section ◽  
Cold Start ◽  
Population Synthesis ◽  
Hot Start ◽  
Gas Accretion ◽  
Planetary Magnetic Field

Here a physical model for terminating giant planet formation is outlined and compared to other methods of late-stage giant planet formation. As has been pointed out before, gas accreting into a gap and onto the planet will encounter the planetary dynamo-generated magnetic field. The planetary magnetic field produces an effective cross section through which gas is accreted. Gas outside this cross section is recycled into the protoplanetary disk, hence only a fraction of mass that is accreted into the gap remains bound to the planet. This cross section inversely scales with the planetary mass, which naturally leads to stalled planetary growth late in the formation process. We show that this method naturally leads to Jupiter-mass planets and does not invoke any artificial truncation of gas accretion, as has been done in some previous population synthesis models. The mass accretion rate depends on the radius of the growing planet after the gap has opened, and we show that so-called hot-start planets tend to become more massive than cold-start planets. When this result is combined with population synthesis models, it might show observable signatures of cold-start versus hot-start planets in the exoplanet population.

Simulation of a Single Cylinder Diesel Engine Under Cold Start Conditions Using Simulink

2000 ◽  
Vol 123 (1) ◽  
pp. 117-124 ◽  
Author(s):  
H.-Q. Liu ◽  
N. G. Chalhoub ◽  
N. Henein
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Cold Start ◽  
Operating Conditions ◽  
Combustion Model ◽  
Nonlinear Dynamic Model ◽  
Single Cylinder ◽  
Engine Model ◽  
Simulink Model ◽  
Engine Components

A nonlinear dynamic model is developed in this study to simulate the overall performance of a naturally aspirated, single cylinder, four-stroke, direct injection diesel engine under cold start and fully warmed-up conditions. The model considers the filling and emptying processes of the cylinder, blowby, intake, and exhaust manifolds. A single zone combustion model is implemented and the heat transfer in the cylinder, intake, and exhaust manifolds are accounted for. Moreover, the derivations include the dynamics of the crank-slider mechanism and employ an empirical model to estimate the instantaneous frictional losses in different engine components. The formulation is coded in modular form whereby each module, which represents a single process in the engine, is introduced as a single block in an overall Simulink engine model. The numerical accuracy of the Simulink model is verified by comparing its results to those generated by integrating the engine formulation using IMSL stiff integration routines. The engine model is validated by the close match between the predicted and measured cylinder gas pressure and engine instantaneous speed under motoring, steady-state, and transient cold start operating conditions.

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