Application of Over-Expansion Cycle to a Larger Gasoline Engine With Late-Closing of Intake Valves

2002 ◽  
Author(s):  
Seiichi Shiga ◽  
Kenji Nishida ◽  
Shizuo Yagi ◽  
Youichi Miyashita ◽  
Yoshiharu Yuzawa ◽  
...  
Keyword(s):  
Compression Ratio ◽  
Thermal Efficiency ◽  
Gasoline Engine ◽  
Engine Performance ◽  
Mechanical Efficiency ◽  
Expansion Ratio ◽  
Brake Thermal Efficiency ◽  
Gasoline Engines ◽  
Cylinder Test ◽  
Test Engine

This paper presents further investigation into the effect of over-expansion cycle with late-closing of intake valves on the engine performance in gasoline engines. A larger single-cylinder test engine with the stroke volume of 650 cc was used with four kinds of expansion ratio (geometrical compression ratio) from 10 to 25 and four sets of intake valve closure (I.V.C.) timings from 0 to 110 deg C.A. ABDC. Late-closing has an effect of decreasing the pumping work due to the reduction of intake vacuum, althogh higher expansion ratio increases the friction work due to the average cylinder pressure level. Combining the higher expansion ratio with the late-closing determines the mechanical efficiency on the basis of these two contrastive effects. The indicated thermal efficiency is mostly determined by the expansion ratio and little affected by the nominal compression ratio. The value of the indicated thermal efficiency reaches to 48% at most which is almost comparable with the value of diesel engines. The improvement of both indicated and brake thermal efficiency reaches to 16% which is much higher than ever reported by the authors. A simple thermodynamic calculation could successfully explain the behavior of the indicated thermal efficiency. The brake thermal efficiency could also be improved due to the increase in both mechanical and indicated efficiencies.

scholarly journals Influence of Ethanol-Gasoline Fuel Fractions on Variable Compression Ratio Engine

2019 ◽  
Vol 8 (3) ◽  
pp. 2929-2936
Keyword(s):  
Compression Ratio ◽  
Gasoline Engine ◽  
Engine Performance ◽  
Calorific Value ◽  
Mechanical Efficiency ◽  
Spark Ignition Engine ◽  
Brake Thermal Efficiency ◽  
Variable Compression Ratio Engine ◽  
Power Outputs ◽  
Fuel Fraction

Increase in demand of ethanol as blending fuel with gasoline is increasing. For noting the performance of the engine, experimentations are required to be done on engine, fuelled with various percentages of ethanol in gasoline. In this study, fuel fractions of ethanol and gasoline were taken for observing the performance of spark ignition engine. One-cylinder gasoline engine was used for conducting the experiments and to analyse the effects of ethanol-gasoline fuel fraction on performance of the engine. The engine was tested at Full Open Throttle condition. The load on the engine was changed by changing the load on Eddy Current Dynamometer to vary the engine speed from 1300 to 1700 rpm in the interval of 100 rpm. Gasoline is blended with ethanol to make five fuel fractions from 0 % ethanol (E0) to 40 % ethanol (E40) in gasoline at the interval of 10% by volume. Engine performance was observed at various Compression Ratio (CR) of the engine as 7,8,9 and 10. Calorific Value (CV) of the fuel fractions observed decreasing from E0 to E40 as CV of ethanol is less than base gasoline. Increase in Brake Specific Fuel Consumption was not very significant with rise in ethanol percentage. Power outputs in terms of Brake Power (BP) was increasing with increase in speed of the engine and observed decreasing with increase in ethanol percentage at constant CR. However various engine output parameters like BP, Mechanical Efficiency found decreasing with increase in fuel fractions ratio. Brake Thermal Efficiency (BTE) was observed decreasing with increase in fuel fractions. However, BTE was observed increasing with increase in CR.

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.

An experimental study on fuel energy saving in gasoline engines using GNP as a lubricant additive

2021 ◽  
pp. 146808742110396
Author(s):  
Gurtej Singh ◽  
Mohammad Farooq Wani ◽  
Mohammad Marouf Wani
Keyword(s):  
Piston Ring ◽  
Energy Savings ◽  
Gasoline Engine ◽  
Engine Performance ◽  
Mechanical Efficiency ◽  
Lubricant Additive ◽  
Lubricating Oil ◽  
Engine Torque ◽  
Gasoline Engines ◽  
Improved Performance

This study concentrates on enhancing the performance of the gasoline engine through nano-lubrication. The effect of Graphene nano-platelets (GNP) as lubricant additives in SAE 15W40 oil on the fuel energy consumption and piston ring wear is investigated. GNP-filled lubricating oil boosted the brake strength, engine torque, and mechanical efficiency, whereas the gasoline engine’s brake specific fuel consumption (BSFC) decreased by 5.3%–6.5% due to a 1.7%–3.46% improvement in engine mechanical efficiency. Further, emission results showed that the GNP-filled lubricating oil reduced the emissions of the engine by approximately 3%–6% as compared to the virgin lubricating oil. Furthermore, the piston ring wear was found to reduce by using GNP-filled nano-lubricant. The characterization of the worn piston ring surfaces showed that the tribo-film formed on wear tracks resulted in the improved performance of the engine thereby reducing abrasive wear and surface roughness. From these studies, an attempt has been made to co-relate engine performance characteristics with tribological perception to contribute in the direction of energy savings and fuel economy.

scholarly journals Experimental study of VCR engine performance analysis using python module

2021 ◽  
Vol 2070 (1) ◽  
pp. 012179
Author(s):  
K Udya Sri ◽  
B S N Murthy ◽  
N Mohan Rao
Keyword(s):  
Compression Ratio ◽  
Fossil Fuels ◽  
Research Effort ◽  
Linseed Oil ◽  
Engine Performance ◽  
Brake Thermal Efficiency ◽  
Load Variations ◽  
Oil Blends ◽  
Compression Ignition Engines ◽  
Test Engine

Abstract Petroleum is non-renewable supply of energy and also the diminution of natural fuel resources, leads to explore for various fuels for cars. The critical search for various fuels for compression ignition engines has been paying interest on fuels obtained from hydrogen and linseed oil plays a significant role in alternate fuel for C.I Engines. The aim of this research effort is to appraise the property of Linseed oil and Hydrogen as dual blend recital on a variable Compression ratio diesel engine. This really provides the discharge individualism of linseed oil amalgamated with gas and its blends with diesel and are taken up for study. Vertical, 4-stroke, water cooled VCR engine with Linseed oil blends for a extensive series of engine load conditions such as Diesel, B10, B20, B40 along with 5lpm, 10lpm and 15lpm of hydrogen were performed. The brake thermal competence of B20 is found nearly closer to diesel fuel with minimum vibrations and less emissions of CO, hydro carbons HC and slight increase in NOx when compared to fossil fuels. During the experiments, vibrations, performance uniqueness of the test engine was analysed and compared with the precise VCR diesel vibrations, fuel performance. The results obtained by using Python module and the best suited code is derived and found that the combined increase of compression ratio and injecting timing increases the brake thermal efficiency and reduces specific fuel consumption. This module helps and reduces each load variations and performances compared tp experimental. Diesel (25%) saved, will greatly meet the demand of fuel in automobiles.

scholarly journals Nissan gasoline engine strategy for higher thermal efficiency

2017 ◽  
Vol 169 (2) ◽  
pp. 141-145 ◽  
Author(s):  
Hideaki MIZUNO
Keyword(s):  
Heat Capacity ◽  
Energy Loss ◽  
Compression Ratio ◽  
Thermal Efficiency ◽  
Gasoline Engine ◽  
Loss Reduction ◽  
Miller Cycle ◽  
High Compression Ratio ◽  
Gasoline Engines ◽  
Evolution Trend

Rising highly concern about the environment has led to demands for the improvement of the efficiency of gasoline engines. Engine thermal efficiency will reach about 40% by technologies as boosted EGR, miller cycle and so on. This evolution trend will be continuously required to survive engines for the future. In this background, further improvement based on theoretical thermal efficiency of high compression ratio and specific heat capacity should be promoted. In addition, energy loss reduction such as represented by cooling loss and friction is also very important for the efficient and effective improvement. NISSAN’s challenges will be introduced to solve these propositions.

scholarly journals Thermal efficiency investigations on the self-ignition test engine fed with marine low sulfur diesel fuels

2019 ◽  
Vol 178 (3) ◽  
pp. 15-19
Author(s):  
Zbigniew KORCZEWSKI
Keyword(s):  
Thermal Efficiency ◽  
Power Plants ◽  
Engine Performance ◽  
The Self ◽  
Laboratory Research ◽  
Diesel Fuels ◽  
University Of Technology ◽  
Marine Diesel ◽  
Test Engine ◽  
Low Sulfur

Within the article an issues of implementing the new kinds of marine diesel fuels into ships’ operation was described taking into ac-count restrictions on the permissible sulphur content introduced by the International Maritime Organization. This is a new situation for ship owners and fuel producers, which forces the necessity to carry out laboratory research tests on especially adapted engine stands. How to elaborate the method enabling quality assessment of the self-ignition engine performance, considered in three categories: ener-gy, emission and reliability, represents the key issue of the organization of such research. In the field of energy research, it is necessary to know the thermal efficiency of the engine as the basic comparative parameter applied in diagnostic analyzes and syntheses of sequen-tially tested marine diesel fuels. This type of scientific research has been worked out for two years in the Department of Marine and Land Power Plants of the Gdańsk University of Technology, as a part of the statutory activities conducted in cooperation with the Regional Fund for Environmental Protection in Gdansk and the LOTOS Group oil company. This article presents the algorithm and results of thermal efficiency calculations of the Farymann Diesel D10 test engine in the con-ditions of feeding with various low-sulfur marine diesel fuels: distillation and residual fuels. This parameters stands for one of ten diag-nostic measures of the ranking of energy and emission quality of newly manufactured marine diesel fuels being built at the Department.

Performance Analysis and Improvement Approach of HEV Extended Expansion Gasoline Engine

2011 ◽  
Vol 317-319 ◽  
pp. 1999-2006
Author(s):  
Yu Wan ◽  
Ai Min Du ◽  
Da Shao ◽  
Guo Qiang Li
Keyword(s):  
Mathematical Model ◽  
Performance Analysis ◽  
Fuel Consumption ◽  
Economic Performance ◽  
Gasoline Engine ◽  
Engine Performance ◽  
Valve Train ◽  
Gasoline Engines ◽  
Simulation Results ◽  
Negative Impacts

According to the boost mathematical model verified by experiments, the valve train of traditional gasoline engine is optimized and improved to achieve extended expansion cycle. The simulation results of extended expansion gasoline engine shows that the extended expansion gasoline engine has a better economic performance, compared to traditional gasoline engines. The average brake special fuel consumption (BSFC) can reduce 22.78 g / kW•h by LIVC, but the negative impacts of extended expansion gasoline engine restrict the potential of extended expansion gasoline engine. This paper analyzes the extended expansion gasoline engine performance under the influence of LIVC, discusses the way to further improve extended expansion gasoline engine performance.

scholarly journals EFFECT OF COMPRESSION RATIO ON PERFORMANCE OF A HYDROGEN BLENDED CNG-DIESEL DUAL FUEL ENGINE

2015 ◽  
Vol 44 (2) ◽  
pp. 87-93 ◽  
Author(s):  
Sridhara Reddy ◽  
Maheswar Dutta ◽  
K.Vijaya Kumar Reddy
Keyword(s):  
Energy Consumption ◽  
Specific Energy ◽  
Compression Ratio ◽  
Thermal Efficiency ◽  
Specific Energy Consumption ◽  
Dual Fuel ◽  
Operating Parameters ◽  
Brake Thermal Efficiency ◽  
Performance And Emission ◽  
Emission Behavior

Compression ratios of the engine considerably affect the performance and emission behavior of an engine.The paper discusses about effect of compression ratios on the operating parameters such as brake specific fuelconsumption (BSFC), brake specific energy consumption (BSEC), brake thermal efficiency (BTE) and volumetricefficiency on a stationary diesel-CNG dual fuel engine by adding hydrogen fraction as a combustion booster. Theexhaust emission behavior of the engine is also presented. Addition of hydrogen in CNG has given better resultsthan diesel-CNG dual fuel operation of the engine. The volumetric efficiency and emissions like NOx are theparameters which needed attention towards this study. The paper presents experimental results and analyzes them.

Use of Ethanol Based Oxygenates for Smoke Reduction in C.I. Engines

2005 ◽  
Author(s):  
Dhananjay B. Zodpe ◽  
Nishikant V. Deshpande
Keyword(s):  
Experimental Investigation ◽  
Fuel Economy ◽  
Diesel Engines ◽  
Thermal Efficiency ◽  
Substantial Reduction ◽  
Brake Thermal Efficiency ◽  
Gasoline Engines ◽  
Brake Power ◽  
Smoke Density ◽  
Harmful Effects

Diesel Engines have better fuel economy compared to gasoline engines. Society is now aware of various harmful effects of pollution and various researchers are trying to use fuel reformulation method to meet the forthcoming stringent air pollution norms for the diesel engines. This paper presents an experimental investigation on use of three different low price ethanol based oxygenate-diesel blends (oxygenate 4, 8 and 12% in blend) as an oxygen enriched fuel in diesel engine and its effect on brake thermal efficiency, smoke density and emissions of CO, HC, NOx etc is studied. It was observed that there is substantial reduction in the smoke density of exhaust gases and the observed reduction was found proportional to the mass of oxygen present in the blend. Marginal increase in NOx and brake thermal efficiency was observed and there was no significant change in the brake power of the engine.

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