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

2017 ◽  
Vol 232 (2) ◽  
pp. 238-253 ◽  
Author(s):  
Yongsheng He ◽  
David Sun ◽  
Jim Liu ◽  
Bin Zhu
Keyword(s):  
Power Consumption ◽  
Fuel Consumption ◽  
Air Flow ◽  
Expansion Ratio ◽  
Spark Ignition Engine ◽  
Engine Fuel ◽  
Miller Cycle ◽  
Engine Torque ◽  
Variable Valve Actuation ◽  
System Configurations

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.

Development of an aggressive Miller Cycle engine with extended Late-Intake-Valve-Closing and a two-stage turbocharger

2017 ◽  
Vol 233 (2) ◽  
pp. 413-426 ◽  
Author(s):  
Yongsheng He ◽  
Jim Liu ◽  
David Sun ◽  
Bin Zhu
Keyword(s):  
Fuel Consumption ◽  
Gasoline Engine ◽  
Expansion Ratio ◽  
Spark Ignition Engine ◽  
Friction Reduction ◽  
Miller Cycle ◽  
Intake Valve ◽  
Two Stage ◽  
Light Load ◽  
Brake Mean Effective Pressure

This paper describes the development of an aggressive Miller cycle gasoline engine with stoichiometric combustion, a high expansion ratio of 12.5:1, a 65 crank angle degrees (CAD) longer duration Late-Intake-Valve-Closing (LIVC) cam, and a two-stage turbocharger. The full-load performance and part-load fuel consumption of the baseline and Miller cycle engines were assessed through engine dynamometer testing. The aggressive Miller cycle engine achieved the maximum Brake Mean Effective Pressure (BMEP) of 22 bar at 1500 rpm, which was enabled by the 65 CAD longer duration LIVC cam to further reduce the effective compression for controlling knock and by the two-stage turbocharger to provide significantly higher boost for maintaining and increasing trapped mass. It was shown that the more aggressive Millerization was realized while maintaining the specific output and advantages of current downsized boosted engines, such as lower friction and lower pumping losses. The aggressive Miller cycle engine achieved above 6% brake-specific fuel consumption (BSFC) reduction over the baseline turbocharged spark-ignition engine on average. The 65 CAD longer duration LIVC cam provided the benefit of pumping loss reduction with delayed intake valve closing and the benefit of hot residual dilution with relatively advanced intake cam phasing simultaneously, which provided the significant fuel economy improvement at non-knocking light-load conditions. Even without the latest technology enhancements and friction reduction methods on its base engine hardware, the aggressive Miller cycle engine achieved a very broad BSFC island of 230 g/kWh or lower, with the lowest BSFC of 223 g/kWh at 2000 rpm and 10 bar BMEP.

Dynamic Modeling and Control of an Hybrid Electric Powertrain for Simulation Under Transient Conditions

2009 ◽  
Author(s):  
Ronan Crosnier ◽  
Jean-Franc¸ois Hetet
Keyword(s):  
Fuel Consumption ◽  
Hybrid Electric Vehicle ◽  
Power Stroke ◽  
Engine Fuel ◽  
Energy Management Strategy ◽  
Modeling And Control ◽  
Engine Torque ◽  
Hybrid Electric ◽  
And Control ◽  
Engine Map

This article presents a causal, forward looking approach for the hybrid electric vehicle where the typical performance engine map representation has been modified. The need for a more physical model of the power stroke process has been fulfilled with “the filling and emptying” method. The thermodynamic states in the intake and exhaust systems are calculated, while the in-cylinder process is still based on the engine fuel consumption map as a calibrated data. Comparisons with the conventional model are established, most important is the response of the engine torque under the load demand. This notion of an “available” torque is taken into account by the energy management strategy. Changes on the distribution of energy flow in order to meet the required torque at the wheel are observed and influence of this modelisation on the fuel consumption over various driving cycles is evaluated.

Joint Air-Fuel Ratio and Torque Regulation Using Secondary Cylinder Air Flow Actuators

1999 ◽  
Vol 121 (4) ◽  
pp. 638-647 ◽  
Author(s):  
A. G. Stefanopoulou ◽  
J. A. Cook ◽  
J. W. Grizzle ◽  
J. S. Freudenberg
Keyword(s):  
Air Flow ◽  
Dynamic Control ◽  
Spark Ignition Engine ◽  
Fuel Injectors ◽  
Engine Torque ◽  
Fuel Ratio ◽  
Torque Response ◽  
Transient Control ◽  
Control Community ◽  
Actuation Scheme

Actuation schemes exist that permit the joint management of air and fuel flow into the cylinders of a spark ignition engine. With the exception of drive by wire systems, to-date, the transient control aspects of these schemes, collectively refered to here as secondary cylinder air flow actuators, has not received any attention from the control community. This paper takes a first step in the analysis of the simultaneous dynamic control of air fuel ratio and torque response using secondary actuators placed before the intake ports of the cylinders, when used in combination with standard fuel injectors and primary throttle regulated by the driver. The emphasis is on basic issues of designing a feedforward scheme to enhance actuator authority for feedback control, and the fundamental multivariable nature of the feedback problem. Enhanced transient air-to-fuel ratio performance improvement is shown to be possible without sacrificing engine torque response with respect to a conventional engine. In addition, this is achieved with overall higher manifold pressure, offering the possibility of reduced pumping losses in the engine, depending on the actual actuation scheme employed.

Experimental Study of Engine Performance and Fuel Consumption Using Various Blends: Ethanol, Naphthalene and Palm Oil

2016 ◽  
Vol 701 ◽  
pp. 205-210
Author(s):  
Mohammad Irfan Hazmi Ismail ◽  
Rusli Othman ◽  
Loke Kean Koay
Keyword(s):  
Experimental Study ◽  
Fuel Consumption ◽  
Palm Oil ◽  
Engine Speed ◽  
Engine Performance ◽  
Spark Ignition Engine ◽  
Renewable Energy Resources ◽  
Engine Torque ◽  
Fuel Blends ◽  
High Engine Speed

The depletion of fossil fuel resource is creating demand for new renewable energy resources. An experimental study was conducted in order to determine effects of various fuel blends including small amount of ethanol, naphthalene and palm oil in petrol on a single cylinder spark ignition engine. Engine performance and fuel consumption were investigated using an engine dynamometer with various loads and engine speed. Engine performance was obtained by recording the engine torque during low, medium and high engine speed from 1200 rpm - 4700 rpm. Fuel consumption of the blends was determined by the brake specific fuel consumption. Palm oil showed about 50% reduction in engine torque for the blends of 3 % and 5 %, while naphthalene showed about 11% reduction for the engine torque when the engine speed is more than 4000 rpm. Ethanol showed a slight improvement of about 1% in engine torque. 20% of ethanol blending fuel gave out the best result in terms of torque. Besides, 20% of ethanol blend found to be decreased in fuel consumption for about 9% when running at 2500 rpm in comparison with 100% petrol.

Properties, performance, and emissions of methanol-gasoline blends in a spark ignition engine

2005 ◽  
Vol 219 (3) ◽  
pp. 405-412 ◽  
Author(s):  
D H Qi ◽  
Sh Q Liu ◽  
Ch H Zhang ◽  
Y Zh Bian
Keyword(s):  
Phase Separation ◽  
Fuel Consumption ◽  
Volume Fraction ◽  
Specific Energy Consumption ◽  
Motor Fuel ◽  
Spark Ignition Engine ◽  
Engine Torque ◽  
Full Load ◽  
Performance And Emissions ◽  
Hydrocarbon Emission

One of the major problems for the successful application of a methanol-gasoline blend as a motor fuel was the realization of a stable homogeneous liquid phase. This paper studied the effect of ethanol as the co-solvent in the methanol-gasoline blend in order to overcome this problem. In this way, not only was the phase separation problem solved but the methanol ratio in the blend was also increased. The critical phase separation temperature (CPST) of the methanol-gasoline blend increased with increasing water content in the blend, and the addition of ethanol caused the CPST to decrease. M10 (gasoline containing 8.5 vol % methanol and 1.5 vol % ethanol) and M25 (gasoline containing 19 vol % methanol and 6 vol % ethanol) were exploited to test the performance, the fuel consumption, and the exhaust emissions. The results show that the specific fuel consumption of M10 was almost the same as that of gasoline, but that of M25 was higher for all engine speeds at full load. The specific energy consumption of gasoline was higher than that of blends for all engine speeds at full load and that of M25 was lower under low load at a fixed engine speed. The engine torque and power output were observed to be lower than those of gasoline, and it was found that the higher the volume fraction of methanol in blend, the larger the reduction. The hydrocarbon emission concentration of M25 was higher and the nitrogen oxides emission concentration was lower than those of gasoline and M10 for all engine loads. Under low and moderate loads, the carbon monoxide concentration of gasoline was higher than that of methanol-gasoline blends, but under high loads that of M25 was higher.

An Investigation of Supercharged Air Filter System on the Performance of a Spark Ignition Engine

2013 ◽  
Vol 465-466 ◽  
pp. 443-447
Author(s):  
Shukri Zain ◽  
Shaari M. Fazri
Keyword(s):  
Fuel Consumption ◽  
Engine Performance ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Air Filter ◽  
Brake Thermal Efficiency ◽  
Engine Torque ◽  
Automotive Engines ◽  
Brake Mean Effective Pressure ◽  
Air Intake

Considering the enhancement device for air intake systems have been widely available in the market for automotive engines, in this paper, the effect of Supercharged Air Filter (SAF) system on a Spark Ignition (SI) engine were experimentally investigated. Three different types of air filter; standard, conical shape air filter and SAF were tested on a four-stroke single-cylinder engine. The engine was coupled to a 20kW generator dynamometer to measure engine performance parameters; engine torque, engine power (B.P), brake thermal efficiency (BTE), brake specific fuel consumption (BSFC) and brake mean effective pressure (BMEP) at various engine speeds with maximum engine load. The results show that the forced induction system can affect the engine performance but it will make the engines fuel consumption higher than standard system.

scholarly journals A Theoretical Study on the Thermodynamic Cycle of Concept Engine with Miller Cycle

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1051
Author(s):  
Jungmo Oh ◽  
Kichol Noh ◽  
Changhee Lee
Keyword(s):  
Compression Ratio ◽  
Thermal Efficiency ◽  
Engine Performance ◽  
Thermodynamic Cycle ◽  
Expansion Ratio ◽  
Boost Pressure ◽  
Miller Cycle ◽  
Compression Pressure ◽  
Air Mass ◽  
Atkinson Cycle

The Atkinson cycle, where expansion ratio is higher than the compression ratio, is one of the methods used to improve thermal efficiency of engines. Miller improved the Atkinson cycle by controlling the intake- or exhaust-valve closing timing, a technique which is called the Miller cycle. The Otto–Miller cycle can improve thermal efficiency and reduce NOx emission by reducing compression work; however, it must compensate for the compression pressure and maintain the intake air mass through an effective compression ratio or turbocharge. Hence, we performed thermodynamic cycle analysis with changes in the intake-valve closing timing for the Otto–Miller cycle and evaluated the engine performance and Miller timing through the resulting problems and solutions. When only the compression ratio was compensated, the theoretical thermal efficiency of the Otto–Miller cycle improved by approximately 18.8% compared to that of the Otto cycle. In terms of thermal efficiency, it is more advantageous to compensate only the compression ratio; however, when considering the output of the engine, it is advantageous to also compensate the boost pressure to maintain the intake air mass flow rate.

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