Diesel Engine Fuel Economy Improvement Enabled by Supercharging and Downspeeding

Keidel, Sean; Wetzel, Philip; Biller, Brandon; Bevan, Karen E.; Birckett, Aaron

doi:10.4271/2012-01-1941

Cited by 25 publications

(13 citation statements)

References 9 publications

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“…Downsizing will move the data distribution in the figure towards smaller bore and higher power density. Down-speeding (Mayer et al, 1982;ostrowski et al, 2012;Keidel et al, 2012) can reduce BSFC via reduced engine delta P, increased load factor, and reduced mechanical friction. The turbine area may need to be downsized in some down-speeding strategy and therefore it may increase engine delta P and offset the gain in pumping loss reduction to a certain extent.…”

Section: 6mentioning

confidence: 98%

Improving the environmental performance of heavy-duty vehicles and engines: particular technologies

Xin

Pinzon

2014

Alternative Fuels and Advanced Vehicle Technologies for Improved Environmental Performance

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Section: 6mentioning

confidence: 98%

Improving the environmental performance of heavy-duty vehicles and engines: particular technologies

Xin

Pinzon

2014

Alternative Fuels and Advanced Vehicle Technologies for Improved Environmental Performance

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“…The HP configuration generally has lower corrected flows. Therefore the HP unit, with a smaller compressor, can cover the entire engine map [9], unlike the LP unit. This is shown in Figure 6 by plotting the maximum air flow increase into the engine using the LP eSC ( Figure 6-a) relative to the baseline turbocharged engine and the difference between the engine air flow in the HP and LP eSC configurations ( Figure 6-b) calculated as: (2) In equation 2, both W air,HP and W air,LP are calculated with the eSC at maximum power and with an injected fuel mass similar to the baseline engine.…”

Section: Lp-hp Comparison At Steady Statementioning

confidence: 99%

“…The selection of either HP or LP implementation is driven by several factors. For example, the lower corrected mass flow rate of HP supercharging covers the full engine speed-load map without choking [8,9]. In addition, for a similar pressure ratio and at high air mass flow rates, the rotational speed of the HP supercharger is lower than an LP one, affecting both electric motor (EM) and compressor efficiency [10].…”

Section: Introductionmentioning

confidence: 99%

Comparison of High- and Low-Pressure Electric Supercharging of a HDD Engine: Steady State and Dynamic Air-Path Considerations

Salehi¹,

Martz²,

Stefanopoulou³

et al. 2016

SAE Technical Paper Series

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This paper numerically investigates the performance implications of the use of an electric supercharger in a heavy-duty DD13 diesel engine. Two electric supercharger configurations are examined. The first is a high-pressure (HP) configuration where the supercharger is placed after the turbocharger compressor, while the second is a low-pressure (LP) one, where the supercharger is placed before the turbocharger compressor. At steady state, high engine speed operation, the airflows of the HP and LP implementations can vary by as much as 20%. For transient operation under the Federal Test Procedure (FTP) heavy duty diesel (HDD) engine transient drive cycle, supercharging is required only at very low engine speeds to improve airflow and torque. Under the low speed transient conditions, both the LP and HP configurations show similar increases in torque response so that there are 44 fewer engine cycles at the smoke-limit relative to the baseline turbocharged engine. When the requested engine torque rise rate is increased from the FTP ramps to steps, the benefit of supercharging is extended to also include mid-range engine speeds, with over ∼ 70% fewer cycles at the smoke-limit line. In addition, the results show an improvement in the overall fuel economy of the supercharged engine during low engine speed transients compared to the baseline turbocharged engine. The study highlights the importance of supercharger bypass valve control, where the transient response of the valve should be twice as fast as the electric supercharger drive motor for accurate and minimal supercharger power consumption during transient maneuvers. Finally, an engine re-calibration with increased exhaust gas recirculation at low engine speeds/loads, resulted 4.6% fuel economy improvements at that low speed/load region while the supercharger enabled fast air-flow increase during aggressive tip-ins.

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“…6,7 The boosting system layouts and the vehicle fuel economy benefits of using a turbocharger and supercharger compound boosting system have been explored in CI engine applications. [8][9][10][11][12] The TC-SC configuration was chosen over the SC-TC configuration in a 15 l CI engine for class 8 line-haul vehicles, a 13 l CI engine for class 8 vocational vehicles and a 6.7 l CI engine for class 6 pickup and delivery vehicles, considering its advantages of an improved fuel economy, a smaller supercharger size and the ability to have midpressure loop exhaust gas recirculation. 8 The simulations indicated that the engine using the TC-SC two-stage boosting system (with engine downspeeding) improved the fuel economy over the baseline engine with only a turbocharger, while maintaining or improving the vehicle performance in all three applications.…”

Section: Introductionmentioning

confidence: 99%

Optimization of a turbocharger and supercharger compound boosting system for a Miller cycle engine

Sun

Liu

Zhu

2017

Proceedings of the Institution of Mechanical Engineers, Part D:

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This paper describes the design optimization of a compound boosting system consisting of a turbocharger and a supercharger for a 2.0 l four-cylinder Miller cycle engine which has a high expansion ratio of 12.0:1 and variable valve actuation. Various system configurations and supercharger sizes were evaluated numerically and experimentally to reduce the supercharger power consumption and the engine fuel consumption while maintaining the same engine torque performance in steady-state conditions. The supercharger–turbocharger boosting system with a V400 supercharger showed an average engine fuel consumption that was 2.8% lower in boosted conditions than did the turbocharger–supercharger boosting system with the same V400 supercharger; this was predicted by engine cycle simulations and verified by experiments. When the supercharger was placed upstream of the turbocharger, the supercharger inlet pressure was lower and the total mass flow rate through the supercharger was reduced, which reduced the supercharger power consumption and the bypass air flow. The turbocharger–supercharger boosting system with a smaller supercharger (R340 or V250) significantly improved the engine efficiency (by 3.3% or 5.0% respectively in comparison with the turbocharger–supercharger boosting system with a V400 supercharger), by reducing the mass air flow rates through the supercharger and minimizing the supercharger power consumption. The turbocharger–supercharger boosting system with a V250 supercharger achieved the lowest engine fuel consumption in full-load conditions of all the turbocharger and supercharger compound boosting system options evaluated for the 2.0 l Miller cycle engine on the basis of the simulation results. This study defined the optimal system layout and the optimal supercharger size for implementing the turbocharger and supercharger compound boosting system on a 2.0 l Miller cycle spark ignition engine to maximize the improvement in the fuel economy of the vehicle while maintaining the same torque performance.

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Diesel Engine Fuel Economy Improvement Enabled by Supercharging and Downspeeding

Cited by 25 publications

References 9 publications

Improving the environmental performance of heavy-duty vehicles and engines: particular technologies

Improving the environmental performance of heavy-duty vehicles and engines: particular technologies

Comparison of High- and Low-Pressure Electric Supercharging of a HDD Engine: Steady State and Dynamic Air-Path Considerations

Optimization of a turbocharger and supercharger compound boosting system for a Miller cycle engine

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