Electric Turbo Assist as an Enabler for Engine Downspeeding

2012 ◽  
Author(s):  
Aaron W. Costall ◽  
Radoslav Ivanov ◽  
Thomas P. F. Langley
Keyword(s):  
System Performance ◽  
Exhaust Gas ◽  
Fuel Saving ◽  
Simulation Tools ◽  
Cycle Simulation ◽  
Air System ◽  
Performance And Emissions ◽  
Simulation Results ◽  
Exhaust Energy ◽  
Gas Recirculation

Electric Turbo Assist (ETA) is a novel air system technology that provides an extra degree of freedom in engine-turbocharger matching for optimal system performance and emissions. This paper presents simulation results from a research project to develop and demonstrate ETA, an integrated turbocharger-motor/generator, for a particular off-road machine duty cycle. Engine cycle simulation tools have been employed to investigate the potential of ETA to reduce fuel consumption through a combined downspeeding and exhaust energy regeneration strategy while meeting the required emissions levels and maintaining the desired engine response. Results show that ETA enables a flexible air system that can meet and even exceed the required air-fuel ratio and exhaust gas recirculation targets when the engine is downspeeded, while providing a useful fuel saving over the non-ETA baseline engine calibration.

Application of an Experimental EGR System to a Medium Speed EMD Marine Engine

2009 ◽  
Author(s):  
John Hedrick ◽  
Steven G. Fritz ◽  
Ted Stewart
Keyword(s):  
Nox Reduction ◽  
Injection Timing ◽  
Exhaust Gas ◽  
Marine Engine ◽  
Air Temperatures ◽  
Medium Speed ◽  
Particulate Matter Emissions ◽  
Baseline Test ◽  
Exhaust Energy ◽  
Gas Recirculation

This paper focuses on quantifying emission reductions associated with various on-engine technologies applied to Electro-Motive Diesel two-cycle diesel engines, which are very popular in marine and locomotive applications in North America. This paper investigates the benefits of using exhaust gas recirculation (EGR), separate circuit aftercooler, and retarded injection timing on a EMD 12-645E7 marine engine. The EGR system alone provided up to a 32.9% reduction in brake specific Nitrogen Oxides (NOx) emissions while demonstrating less than one percent increase in cycle brake specific fuel consumption (BSFC). The brake specific particulate matter emissions increased somewhat, but at a modest rate based on the amount of NOx emission reduction. When the enhanced aftercooler system was combined with the addition of EGR, there was a 31.9% reduction in NOx and essentially no change to the BSFC when compared to the baseline test. The minimum manifold air temperature (MAT) was limited due to the size of the standard EMD aftercooler heat exchanger that is fitted on the engine. No efforts to modify the turbocharger to improve the turbo match to take advantage of the lower manifold air temperatures and the corresponding lower exhaust energy. Once 4° static injection timing retard was introduced, along with the EGR and the minimum MAT, a maximum NOx reduction of 49% was realized with only a 1.1% increase over the baseline BSFC.

An experimental investigation on performance, emissions, and combustion in a manifold injection for different exhaust gas recirculation flowrates in hydrogen—diesel dual-fuel operations

2008 ◽  
Vol 222 (11) ◽  
pp. 2131-2145 ◽  
Author(s):  
N Saravanan ◽  
G Nagarajan
Keyword(s):  
Experimental Investigation ◽  
Exhaust Gas Recirculation ◽  
Intake Manifold ◽  
Dual Fuel ◽  
Injection Timing ◽  
Exhaust Gas ◽  
Exhaust Gases ◽  
Injection Duration ◽  
Performance And Emissions ◽  
Gas Recirculation

Hydrogen is receiving considerable attention as an alternative fuel to replace the rapidly depleting petroleum-based fuels. Its clean burning characteristics help to meet the stringent emission norms. In this experimental investigation a single-cylinder diesel engine was converted to operate in hydrogen—diesel dual-fuel mode. Hydrogen was injected in the intake manifold and the diesel was injected directly inside the cylinder. The injection timing and the injection duration of hydrogen were optimized on the basis of performance and emissions. Best results were obtained with hydrogen injection at gas exchange top dead centre with an injection duration of 30° crank angle. The flowrate of hydrogen was optimized as 7.5l/min with optimized injection timing and duration. The optimized exhaust gas recirculation (EGR) flowrate was 20 per cent at 75 per cent load. The optimized timings were chosen on the basis of performance, emission, and combustion characteristics. The EGR technique was adopted in the hydrogen—diesel dual-fuel mode by varying the EGR flowrate from 0 per cent to 25 per cent in steps of 5 per cent. The maximum quantity of exhaust gases recycled during the test was 25 per cent (up to 75 per cent load); beyond that unstable combustion was observed with an increase in smoke. The brake thermal efficiency with 20 per cent EGR decreases by 9 per cent compared with diesel. The nitrogen oxide (NO x) emission in hydrogen manifold injection decreases by threefold with 20 per cent EGR operation at full load. The NO x emission tends to reduce drastically with increase in the EGR percentage at all load conditions owing to the increase in heat capacity of the exhaust gases. The smoke decreases by 80 per cent in the dual-fuel operation compared with diesel at 75 per cent load.

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