MODELING OF THE DIESEL-ENGINE OPERATION PROCESS WITH EXHAUST GAS RECIRCULATION ON THE BASIS OF A DETAILED KINETIC MECHANISM OF FUEL COMBUSTION

Author(s):  
S. S. Sergeev ◽  
◽  
S. M. Frolov ◽  
V. Ya. Basevich ◽  
B. Basara ◽  
...  
2018 ◽  
Vol 29 (3) ◽  
pp. 372-391 ◽  
Author(s):  
M Krishnamoorthi ◽  
R Malayalamurthi

The threat of fossil fuel depletion and augmented environmental pollution caused by diesel fleets can be curbed by adopting suitable fuel and engine modifications. In the present work, effects of engine speed (r/min), injection timing, injection pressure and compression ratio on performance and emission characteristics of a compression ignition engine were investigated. The ternary test fuel of 65% diesel + 25% bael oil + 10% diethyl ether has been used, where the tests have been conducted at different charge inlet temperature and exhaust gas recirculation. All the experiments were conducted at the trade-off engine load that is 75% engine load. When the diesel engine operating with 320 K charge inlet temperature, brake thermal efficiency has been improved to 28.6%. Meanwhile reduced emission levels of carbon monoxide (0.025%) and hydrocarbon (12.3 ppm) were observed during the engine operation with 320 K charge inlet temperature and compression ratio of 18:1. The oxides of nitrogen have been reduced to 226 ppm at 16:1 compression ratio with 30% exhaust gas recirculation mode.


2017 ◽  
Vol 19 (5) ◽  
pp. 542-552 ◽  
Author(s):  
Gurneesh Jatana ◽  
Lyle Kocher ◽  
Suk-Min Moon ◽  
Sriram Popuri ◽  
Kevin Augustin ◽  
...  

The combustion-residual backflow into the intake ports of a commercial diesel engine (Cummins ISX series) was spatiotemporally mapped using a multiplexed multi-species absorption spectroscopy sensor system; the resulting cycle- and cylinder-resolved measurements are applicable for assessing cylinder charge uniformity, control strategies, and computational fluid dynamics tools. On-engine measurements were made using four compact (3/8 in Outside Diameter) stainless steel probes which enabled simultaneous multi-point measurements, required minimal engine hardware modification, and featured a novel tip design for measurement of gas flows parallel to the probe axis. Three sensor probes were used to perform simultaneous backflow measurements in intake runners corresponding to three of the six engine cylinders, and a fourth probe was installed in the intake manifold plenum for tracking dynamics introduced by an external exhaust gas recirculation mixer. Near-crank-angle resolved measurements (5 kHz, that is, 1.2 crank angle resolution at 1000 RPM) were performed during steady-state engine operation at various levels of external exhaust gas recirculation to measure the gas properties and penetration distance of the backflow into the intake runners on a cylinder- and cycle-basis. Validation of computational fluid dynamics model results is also presented to demonstrate the utility of such measurements in advancing engine research.


Author(s):  
Ming Zheng ◽  
David K. Irick ◽  
Jeffrey Hodgson

For diesel engines (CIDI) the excessive use of exhaust gas recirculation (EGR) can reduce in-cylinder oxides of nitrogen (NOx) generation dramatically, but engine operation can also approach zones with high instabilities, usually accompanied with high cycle-to-cycle variations and deteriorated emissions of total hydrocarbon (THC), carbon monoxide (CO), and soot. A new approach has been proposed and tested to eliminate the influences of recycled combustibles on such instabilities, by applying an oxidation catalyst in the high-pressure EGR loop of a turbocharged diesel engine. The testing was directed to identifying the thresholds of stable operation at high rates of EGR without causing cycle-to-cycle variations associated with untreated recycled combustibles. The elimination of recycled combustibles using the oxidation catalyst showed significant influences on stabilizing the cyclic variations, so that the EGR applicable limits are effectively extended. The attainability of low NOx emissions with the catalytically oxidized EGR is also evaluated.


2020 ◽  
Vol 19 (4) ◽  
pp. 305-310
Author(s):  
G. M. Kuharonak ◽  
D. V. Kapskiy ◽  
V. I. Berezun

The purpose of this work is to consider the requirements for emissions of harmful substances of diesel engines by selecting design and adjustment parameters that determine the organization of the workflow, and the exhaust gas cleaning system, taking into account the reduction of fuel consumption. Design elements and geometric characteristics of structures for a turbocharged diesel engine of Д-245 series produced by JSC HMC Minsk Motor Plant (4ЧН11/12.5) with a capacity of 90 kW equipped with an electronically controlled battery fuel injection have been developed: exhaust gas recirculation along the high pressure circuit, shape and dimensions of the combustion chamber, the number and angular arrangement of the nozzle openings in a nozzle atomizer, and inlet channels of the cylinder head. Methods for organizing a workflow are proposed that take into account the shape of the indicator diagrams and affect the emissions of nitrogen oxides and dispersed particles differently. Their implementation allows us to determine the boundary ranges of changes in the control parameters of the fuel supply and exhaust gas recirculation systems when determining the area of minimizing the specific effective fuel consumption and the range of studies for the environmental performance of a diesel engine. The paper presents results of the study on the ways to meet  the requirements for emissions of harmful substances, obtained by considering options for the organization of working processes, taking into account the reduction in specific effective fuel consumption, changes in the average temperature of the exhaust gases and diesel equipment. To evaluate these methods, the following indicators have been identified: changes in specific fuel consumption and average temperature of the toxicity cycle relative to the base cycle, the necessary degree of conversion of the purification system for dispersed particles and NOx. Recommendations are given on choosing a diesel engine to meet Stage 4 emission standards for nitrogen oxides and dispersed particles.


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