Combustion optimization for fuel economy improvement of a dedicated range-extender engine

2021 ◽  
pp. 095440702199362
Author(s):  
Zhenkuo Wu ◽  
Zhiyu Han ◽  
Yongsheng Shi ◽  
Wei Liu ◽  
Junwei Zhang ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Compression Ratio ◽  
Fuel Economy ◽  
Intake Port ◽  
Load Range ◽  
Full Load ◽  
Range Extender ◽  
Atkinson Cycle ◽  
Spark Timing ◽  
Fuel Economy Improvement

In this study, the combustion system of a dedicated range-extender engine was optimized based on a production engine for fuel economy improvement with the use of enhanced tumble flow, higher compression ratio, Atkinson cycle and exhaust gas recirculation (EGR). First, the shape of the intake port was optimized to improve in-cylinder tumble and turbulence for combustion enhancement. The computational fluid dynamics (CFD) results showed that compared to the original intake port, the peak tumble ratio during the compression stroke of the new port is improved by 74.0%, and the turbulent kinetic energy at the spark timing is increased by 33.0%, and the results were verified through the flow test bench experiment. The dyno experiment showed that, with the new intake port, the engine brake specific fuel consumption (BSFC) was improved for all test conditions. Then, the late intake valve closing (IVC) and a higher compression ratio were used in combination to adopt the Atkinson cycle. The IVC timing was set to 642° ATDC based on the preset power target. And the compression ratio was set to 12 to balance knock tendency and BSFC improvement. Finally, the cooled EGR was optimized to further suppress the knocking tendency to improve fuel consumption. The results showed that, with the cooling Strategy 2, the attainable maximum EGR ratio at 2400 rpm full load and 70 Nm conditions was increased, the spark timing could be significantly advanced, and the BSFC was improved. The improvement of BSFC is between 6 g/kW·h and 13 g/kW·h for the load range from 40 Nm to the full load. After the optimization, the minimum BSFC of the range-extender engine reaches 233 g/kW·h, while it is around 242 g/kW·h for the base engine. The operation area where fuel consumption is lower than 240 g/kW·h becomes much wider.

scholarly journals A Comparison Between Two-Position Variable Compression Ratio and Continuously Variable Compression Ratio Engines Using Numerical Simulation

2009 ◽  
Author(s):  
Ray Malpress ◽  
David R. Buttsworth
Keyword(s):  
Numerical Simulation ◽  
Fuel Consumption ◽  
Compression Ratio ◽  
Feedback Mechanism ◽  
Driving Cycle ◽  
Load Range ◽  
Variable Compression Ratio ◽  
Full Load ◽  
Acceleration Rate ◽  
Variable Compression

Two types of variable compression ratio engine are considered: i) a continuously variable compression ratio (VCR) device that optimises engine efficiency at all loads, and ii) a VCR device that allows the engine to operate at one of two discrete compression ratios. The simulated engine configuration uses late intake valve closing (LIVC). A maximum geometric compression ratio (GCR) of 17:1 is adopted in the simulations resulting in a constant effective compression ratio of 10.2:1 in all configurations. Reduction from full load is achieved in the simulation with LIVC until the maximum GCR is reached after which lower loads are achieved through throttling. In the two-position VCR engine simulation, the full load range is achieved through throttling in combination with LIVC. At part load, in combination with LIVC, the VCR devices increase the geometric compression ratio to return the effective compression ratio to that for full load in each case. Fuel consumption for the New European Driving Cycle (NEDC) is assessed via numerical simulation for a representative vehicle. The simulations indicate that the increase in net fuel consumption over a driving cycle is effectively no different for the two-position VCR engine relative to a continuously variable CR and this justifies further research into two-position VCR technology. Net fuel consumption can also be improved by the use of a limited acceleration that maintains the engine in the reduced compression stroke configuration. An acceleration rate with a driver feedback mechanism is proposed which, in combination with a two-position VCR engine, shows potential for significant reduction in fuel consumption of greater than 15% relative to the full compression, fixed CR configuration for the NEDC.

Gear oil influences on efficiency of gear and fuel economy of cars

2000 ◽  
Vol 214 (2) ◽  
pp. 189-196 ◽  
Author(s):  
W. J. Bartz
Keyword(s):  
Fuel Consumption ◽  
Fuel Economy ◽  
High Efficiency ◽  
Friction Reduction ◽  
Friction Modifiers ◽  
Oil Viscosity ◽  
Fuel Economy Improvement ◽  
Viscosity Grade ◽  
Gear Oil ◽  
Gear Oils

1. First of all, it should be considered that the fuel consumption of a car depends on a set of parameters only partly related to tribology. Their influence is much more pronounced than that of the lubricant. 2. Only the mechanical losses can be decreased by lubricant-related measures. Therefore, the fuel economy improvement that possibly might be realized is rather limited, especially when taking into account the rather high efficiency of gears. 3. When evaluating the influence of viscosity on fuel consumption, the so-called effective viscosity must be taken into account. This is most important for non-Newtonian oils. 4. Reducing the gear oil viscosity by one SAE viscosity grade will result in fuel consumption reductions of 0.2-1.5 per cent at high temperatures and 0.4-2.5 per cent at low temperatures. 5. Using friction modifiers in gear oils, fuel consumption reductions of between 1.0 and 6.0 per cent are realistic. 6. On the basis of a 50 per cent friction reduction maximum fuel consumption reductions between 1.0 and 5.1 per cent by other gear oils are possible, considering different driving programmes. 7. Tests with a real automobile gear resulted in fuel economy improvements of the order of magnitudes of 1 per cent by other gear oils. 8. The results of measurements confirm in principle the calculated estimations.

Fuel Economy Improvement Strategy for Light Duty Hybrid Truck Based on Fuel Consumption Computational Model Using Neural Network

2008 ◽  
Vol 41 (2) ◽  
pp. 10719-10725 ◽  
Author(s):  
Masahiro Suzuki ◽  
Seiichi Yamaguchi ◽  
Tomohiko Araki ◽  
Pongsathorn Raksincharoensak ◽  
Masao Yoshizawa ◽  
...  
Keyword(s):  
Neural Network ◽  
Computational Model ◽  
Fuel Consumption ◽  
Fuel Economy ◽  
Improvement Strategy ◽  
Light Duty ◽  
Fuel Economy Improvement

Combustion Characteristics of Stratified Mixture in Lean-Burn LPG Direct-Injection Engine With Spray-Guided Combustion System

2014 ◽  
Author(s):  
Cheolwoong Park ◽  
Seungmook Oh ◽  
Taeyoung Kim ◽  
Heechang Oh ◽  
Choongsik Bae
Keyword(s):  
Fuel Consumption ◽  
Compression Ratio ◽  
Fuel Economy ◽  
Direct Injection ◽  
Combustion Process ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Combustion Stability ◽  
Direct Injection Engine ◽  
Brake Mean Effective Pressure

Today, we are faced with the problems of global warming and fossil fuel depletion, and they have led to the enforcement of new emissions regulations. Direct-injection spark-ignition engines are a very promising technology that can comply with the new regulations. These engines offer the advantages of better fuel economy and lower emissions than conventional port-injection engines. The use of LPG as the fuel reduces carbon emissions because of its vaporization characteristics and the fact that it has lower carbon content than gasoline. An experimental study was carried out to investigate the combustion process and emission characteristics of a 2-liter spray-guided LPG direct-injection engine under lean operating conditions. The engine was operated at a constant speed of 2000 rpm under 0.2-MPa brake mean effective pressure, which corresponds to a common operation point of a passenger vehicle. Combustion stability, which is the most important component of engine performance, is closely related to the operation strategy and it significantly influences the degree of fuel consumption reduction. In order to achieve stable combustion with a stratified LPG mixture, an inter-injection spark ignition (ISI) strategy, which is an alternative control strategy to two-stage injection, was employed. The effects of the compression ratio on fuel economy were also assessed; due to the characteristics of the stratified LPG mixture, the fuel consumption did not reduce when the compression ratio was increased.

EGR Effect On Performance of a Spark Ignition Engine Fueled with Blend of Methanol-Gasoline

2013 ◽  
Vol 1 (2) ◽  
pp. 110-92
Author(s):  
Miqdam Tariq Chaichan
Keyword(s):  
Fuel Consumption ◽  
Compression Ratio ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Specific Fuel Consumption ◽  
Exhaust Gas ◽  
Brake Specific Fuel Consumption ◽  
Test Results ◽  
Brake Thermal Efficiency ◽  
Spark Timing

This paper examines the results of performance of a single cylinder spark-   ignition engine fuelled with 20% methanol +80% gasoline (M20), compared to gasoline. The experiments were conducted at stoichiometric air–fuel ratio at wide open throttle and variable speed conditions, over the range of 1000 to 2600 rpm. The tests were conducted at higher useful compression ratio using optimum spark timings and adding recirculated exhaust gas with 20% to suction manifold. The test results show that the higher compression ratio for the tested gasoline was 7:1, 9.5:1 for M20 and 9:1 for M20 with added EGR. M20 at higher useful compression ratio (HUCR) and optimum spark timing (OST) characteristics are significantly different from gasoline. Within the tested speed range, M20 consistently produces higher brake thermal efficiency by about 6%. Also it resulted in approximately 3.06% lower brake specific fuel consumption compared with gasoline. Adding EGR to M20 caused reduction in HUCR and advancing the OST. This addition increased brake specific fuel consumption (BSFC), reduced brake thermal energy, volumetric efficiency and exhaust gas temperatures.

Fuel Economy in Petrol Engines

1940 ◽  
Vol 143 (1) ◽  
pp. 289-312 ◽  
Author(s):  
W. T. David ◽  
A. S. Leah
Keyword(s):  
Fuel Consumption ◽  
Ethyl Alcohol ◽  
Compression Ratio ◽  
Fuel Economy ◽  
Performance Characteristic ◽  
Petrol Engine ◽  
Working Fluid ◽  
Engine Cylinder ◽  
Similar Information ◽  
The Mean

Charts are given in this paper from which may be found the indicated thermal efficiencies, the fuel consumption per indicated horse-power-hour, and the mean effective pressures which are practically attainable in a compact combustion-chambered petrol engine of any bore between 3 inches and 8 inches when running at any compression ratio between 4/1 and 9/1 and at any speed from 1,000 r.p.m. upwards on an octane, ethyl alcohol, or benzene-air mixture of any strength between 20 per cent weak and 20 per cent rich. From these charts similar information in regard to any mixed petrol may be deduced with fair accuracy. The performance of actual engines is compared with the attainable performance in the light of views, given in some detail, relating to phenomena associated with the working fluid and the combustion of the charge. The conclusion is that improvement in charge mixing within each engine cylinder would lead to better performance. Characteristic merit and demerit curves are suggested which appear to be capable of yielding useful information in regard to the functioning of engines.

Development of a Miller cycle engine with single-stage boosting and cooled external exhaust gas recirculation

2016 ◽  
Vol 231 (6) ◽  
pp. 766-780 ◽  
Author(s):  
Yongsheng He ◽  
Jim Liu ◽  
Bin Zhu ◽  
David Sun
Keyword(s):  
Fuel Consumption ◽  
Compression Ratio ◽  
Fuel Economy ◽  
Exhaust Gas Recirculation ◽  
Operating Conditions ◽  
Single Stage ◽  
Exhaust Gas ◽  
Brake Specific Fuel Consumption ◽  
Miller Cycle ◽  
Gas Recirculation

In this paper, the development of a Miller cycle gasoline engine which has a high compression ratio from 11.5:1 to 12.5:1, single-stage turbocharging and external cooled exhaust gas recirculation is described. The improvement in the fuel economy by adding external cooled exhaust gas recirculation to the Miller cycle engine at different geometric compression ratios were experimentally evaluated in part-load operating conditions. The potential of adding external cooled exhaust gas recirculation in full-load conditions to mitigate pre-ignition in order to allow higher geometric compression ratios to be utilized was also assessed. An average of 3.2% additional improvement in the fuel economy was achieved by adding external cooled exhaust gas recirculation to the Miller cycle engine at a geometric compression ratio of 11.5:1. It was also demonstrated that the fuel consumption of the engine with external cooled exhaust gas recirculation was reduced by 3–7% in a wide range of part-load operating conditions and that the engine output of the Miller cycle engine at a geometric compression ratio of 12.5:1 increased at 2000 r/min in the full-load condition. The Miller cycle engine with external cooled exhaust gas recirculation at a geometric compression ratio of 12.5:1 achieved a broad brake specific fuel consumption range of 220 g/kW h or lower, with the lowest brake specific fuel consumption of 215 g/kW h. While there are still challenges in implementing external cooled exhaust gas recirculation, the Miller cycle engine with single-stage turbocharging and external cooled exhaust gas recirculation showed its potential for substantial improvement in the fuel economy as one of the technical pathways to meet future requirements in reducing carbon dioxide emissions.

An Application of Petrol Injection to Automobile Engines

1949 ◽  
Vol 3 (1) ◽  
pp. 133-154 ◽  
Author(s):  
R. Barrington ◽  
E. W. Downing
Keyword(s):  
Fuel Consumption ◽  
Compression Ratio ◽  
Fuel Economy ◽  
Hot Spot ◽  
Direct Injection ◽  
Combustion Efficiency ◽  
Maximum Power ◽  
Injection System ◽  
Fuel Distribution ◽  
Bench Tests

The paper recounts the results obtained in a series of experiments carried out with the object of examining the claims made for improved results, both in fuel consumption and maximum power, which could be obtained by substituting a petrol injection system for a carburettor. The experiments, carried out on four-cylinder engines of approximately 1·5 litres capacity, led to the development of a satisfactory system capable of giving equal fuel distribution to all cylinders with a tolerance of ±2 per cent at all loads. They showed that, for engines of this order of size, manifold injection was superior to direct injection and established that petrol injection will not give any better combustion efficiency than carburation. Hence any saving in fuel consumption obtained can only be due to better fuel distribution between cylinders, better matching of fuel/air ratio to a desired value, or increase in compression ratio made possible by the elimination of the hot spot. Under certain conditions the resultant saving in fuel at part load on bench tests could amount to some 10–15 per cent. Maximum power can be increased by some 15–20 per cent by elimination of the choke, and still more if the compression ratio is increased slightly to take advantage of the reduced temperature of the incoming charge. Road tests in general confirmed the results of bench tests, but brought out the effect of many other factors which affect fuel economy. In order to properly evaluate these a number of experiments were carried out which are of interest and value as affecting the problem of fuel economy in general. Starting at low temperatures requires very considerable over-fuelling with a petrol injection system, just as in the case of a carburettor, but such a system may be made to give better control during the process of warming up. In the authors' view an engine fitted with petrol injection is pleasanter to drive as a result of its inherently better idling, more uniform and smoother torque and increased power at full throttle. The results obtained, however, while attractive, do not bear out some of the more exaggerated claims sometimes made by advocates of petrol injection systems. No attempt is made to urge the introduction of petrol injection and it is left to the industry to decide whether, in view of the results obtained, it is felt that a petrol injection system with its concomitant increase in first cost is worth adoption.

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