Analysis of Engine Efficiency of Diesel Vehicle in Transient Operating Conditions

Turbocharged gas engines for combined heat and power units are optimized to increase efficiency while observing and maintaining legitimate exhaust gas emissions. In order to do so, the charge motion is raised. This study investigates the influence of passive prechamber spark plugs in high turbulent combustion chambers. The subjects of investigation are two different gas engine types, one of them running on sewage gas the other one on biogas. The occurring charge motions initiated by the cylinder heads are measured by integrative determination of swirl motion on a flow bench. In addition, three different passive prechamber spark plugs are characterized by a combustion analysis. Each of the three spark plugs comes with a different electrode or prechamber geometry. The resulting combustion and operating conditions are compared while the equal brake mean effective pressure and constant NOx-emissions are sustained. The results of the combustion analysis show a rising influence of the spark plug with increasing air-to-fuel-ratio induced by charge motion. Furthermore, clear differences between the spark plugs are determined: electrode arrangement and prechamber geometry help to influence lean misfire limits, engine smoothness, start behavior and ignition delay. The results indicate the capability of spark plugs to increase lifetime and engine efficiency.

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Development and Performance Measurement of Oil-Free Turbocharger Supported on Gas Foil Bearings

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4004719 ◽

2012 ◽

Vol 134 (3) ◽

Cited By ~ 15

Author(s):

Yong-Bok Lee ◽

Dong-Jin Park ◽

Tae Ho Kim ◽

Kyuho Sim

Keyword(s):

Power Loss ◽

Time Delays ◽

Operating Conditions ◽

Total Power ◽

Stable Operation ◽

Compressor Wheel ◽

Foil Bearings ◽

Vehicle Engine ◽

Turbine Inlet ◽

Diesel Vehicle

This paper present the development of an oil-free turbocharger (TC) supported on gas foil bearings (GFBs) and its performance evaluation in a test rig driven by a diesel vehicle engine (EG). The rotor-bearing system was designed via a rotordynamic analysis with dynamic force coefficients derived from the analysis of the GFBs. The developed oil-free TC was designed using a hollow rotor with a radial turbine at one end and a compressor wheel at the other end, a center housing with journal and thrust GFBs, and turbine and compressor casings. Preliminary tests driven by pressurized shop air at room temperature demonstrated relatively stable operation up to a TC speed of 90,000 rpm, accompanied by a dominant synchronous motion of ∼20 μm and small subsynchronous motions of less than 2 μm at the higher end of the speed range. Under realistic operating conditions with a diesel vehicle engine at a maximum TC speed of 136,000 rpm and a maximum EG speed of 3140 rpm, EG and TC speeds and gas flow properties were measured. The measured time responses of the TC speed and the turbine inlet pressure demonstrated time delays of ∼3.9 and ∼1.3 s from that of the EG speed during consecutive stepwise EG speed changes, implying the GFB friction and rotor inertia led to time delays of ∼2.6 s. The measured pressures and temperatures showed trends following second-order polynomials against EG speed. Regarding TC efficiency, 4.3 kW of mechanical power was supplied by the turbine and 3.3 kW was consumed by the compressor at the top speed of 136,000 rpm, and the power loss reached 22% of the turbine power. Furthermore, the estimated GFB power losses from the GFB analysis were approximately 25% of the total power loss at higher speeds, indicating the remainder of the power loss resulted from heat transfer from the exhaust gas to the surrounding solid structures. Incidentally, as the TC speed was increased from 45,000 to 136,000 rpm, the estimated turbine inlet power increased from 19 to 79 kW, the compressor exit power increased from 7 to 26 kW, and the TC output mass flow rate from the compressor increased from 21 to 74 g/s. The average TC compressor exit power was estimated at ∼34% of the turbine inlet power over this range.

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Influences of Using B20 Reformulated Type Fuel on a Heavy-Duty Diesel Engine Performances

E3S Web of Conferences ◽

10.1051/e3sconf/201911201002 ◽

2019 ◽

Vol 112 ◽

pp. 01002

Author(s):

Adnan Kadhim Rashid ◽

Bogdan Radu ◽

Alexandru Racovitza ◽

Radu Chiriac

Keyword(s):

Diesel Engine ◽

Operating Conditions ◽

Heavy Duty ◽

Simulation Code ◽

Significant Drop ◽

Engine Efficiency ◽

Heavy Duty Diesel Engine ◽

European Regulations ◽

Heavy Duty Diesel ◽

To Come

Starting from the need to replace up to 20% of the energetic fuel content as European Regulations have already stipulated for the years to come, B20 mixture fuel proves to receive an increasing recognition nowadays as an appropriate and alternative fuel for Diesel engines. Studies have provided that B20 increases engine efficiency under specific operating conditions together with a significant drop of the main emissions’ levels. This paper is proposing a numerical analysis of the operating behavior of an IVECO Cursor 10 heavy-duty Diesel engine fueled with Diesel-Biodiesel B20 fuel, featuring the projections of the AMESIM simulation code.

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Generation of Electrical Energy for Charging of a Battery by using Exhaust Gas Energy

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.j9377.0881019 ◽

2019 ◽

Vol 8 (10) ◽

pp. 2159-2163

Keyword(s):

Combustion Engine ◽

Electrical Energy ◽

Heat Energy ◽

Operating Conditions ◽

Exhaust Gas ◽

Automotive Electronics ◽

Electrical System ◽

Engine Exhaust ◽

Electrical Systems ◽

Engine Efficiency

In present day most of the automobile vehicles runs and depends upon the automotive electronics therefore the need of electrical energy for running the electronics system. By using the exhaust gas energy it can produce the energy or charge the battery or power the electrical systems in different operating conditions. The system assists the existing battery during demand. The gas from combustion engine goes as waste approximately 70%of heat without utilizing properly. An attempt is made to charge the battery and it can use to power the electrical systems by using energy from exhaust gas turbine. It is used for the conversion of heat energy to electrical energy. To charge the battery by using the mechanical power from the engine exhaust manifold turbine without compromising the engine efficiency with limited back pressure. The main aim is to convert the heat energy to electrical energy through turbine which gets the higher out turn energy from the exhaust gases. The exhaust gas is utilized for charging and assisting the electrical system.

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Optimization of Design and Operational Parameters Using Genetic Algorithm for a Spark Ignition Engine With CNG/H2 Mixtures

Energy Conversion and Resources ◽

10.1115/imece2005-82145 ◽

2005 ◽

Author(s):

G. Anand ◽

R. Balamurugan

Keyword(s):

Genetic Algorithm ◽

Spark Ignition ◽

Operating Conditions ◽

Spark Ignition Engine ◽

Nox Emissions ◽

Engine Fuel ◽

Operational Parameters ◽

Si Engine ◽

Engine Efficiency ◽

Wide Range

The present contribution describes the potential of using gaseous fuels like Hythane (CNG/H2 mixtures) as a spark ignition (SI) engine fuel. Genetic Algorithm (GA) is used to optimize the design and operational parameters of a CNG/H2 fueled spark ignition engine for maximizing the engine efficiency subjected to NOx emission constraint. This research deals with quasi-dimensional, two-zone thermodynamic simulation of four-stroke SI engine fueled with CNG/H2 blended fuel for the prediction of the combustion and emission characteristics. The validity of the model has been carried out by comparing the computed results with experimental data obtained under same engine setup and operating conditions. A wide range of engine parameters were optimized using a simple GA regarding both engine efficiency and NOx emissions. The five parameters chosen were compression ratio, engine speed, equivalence ratio, H2 fraction in the fuel, and spark plug position in cylinder head. The amount of NOx emissions was being kept under the constrained value of 750 ppm (< 5 g/kWh), which is less than permissible limit for heavy-duty engines.

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Engine thermomanagement with electrical components for fuel consumption reduction

International Journal of Engine Research ◽

10.1243/14680870260189271 ◽

2002 ◽

Vol 3 (3) ◽

pp. 157-170 ◽

Cited By ~ 19

Author(s):

E Cortona ◽

C. H. Onder ◽

L Guzzella

Keyword(s):

Fuel Consumption ◽

Cooling System ◽

Combustion Engine ◽

Cold Start ◽

Operating Conditions ◽

Coolant Temperature ◽

Engine Operation ◽

Cooling Systems ◽

Engine Efficiency ◽

Model Based

This paper proposes a solution for advanced temperature control of the relevant temperature of a combustion engine. It analyses the possibility of reducing vehicle fuel consumption by improving engine thermomanagement. In conventional applications, combustion engine cooling systems are designed to guarantee sufficient heat removal at full load. The cooling pump is belt-driven by the combustion engine crankshaft, resulting in a direct coupling of engine and cooling pump speeds. It is dimensioned such that it can guarantee adequate performance over the full engine speed range. This causes an excessive flow of cooling fluid at part-load conditions and at engine cold-start. This negatively affects the engine efficiency and, as a consequence, the overall fuel consumption. Moreover, state-of-the-art cooling systems allow the control of the coolant temperature only by expansion thermostats (solid-to-liquid phase wax actuators). The resulting coolant temperature does not permit engine efficiency to be optimized. In this paper, active control of the coolant flow as well as of the coolant temperature has been realized using an electrical cooling pump and an electrically driven valve which controls the flow distribution between the radiator and its bypass. For this purpose, a control-oriented model of the whole cooling system has been derived. Model-based feedforward and feedback controls of coolant temperature and flow have been designed and tested. With the additional actuators and the model-based control scheme, a good performance in terms of fast heat-up and small temperature overshoot has been achieved. The improvements in fuel consumption obtained with the proposed configuration have been verified on a dynamic testbench. Both engine cold-start under stationary engine operation and the European driving cycle MVEG-A with engine cold-start were tested. The fuel consumption reductions achieved during these tests vary between 2.8 and 4.5 per cent, depending on the engine operating conditions. Compared to vehicle mass reduction or internal engine improvements, engine thermomanagement is a simple, flexible and cost efficient solution for improving system performance, i.e. fuel consumption.

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An Organic Rankine Cycle Bottoming a Diesel Engine Powered Passenger Car

Energies ◽

10.3390/en13020314 ◽

2020 ◽

Vol 13 (2) ◽

pp. 314 ◽

Cited By ~ 1

Author(s):

Antonio Mariani ◽

Maria Laura Mastellone ◽

Biagio Morrone ◽

Maria Vittoria Prati ◽

Andrea Unich

Keyword(s):

Diesel Engine ◽

Power Plants ◽

Organic Rankine Cycle ◽

Rankine Cycle ◽

Operating Conditions ◽

Working Fluid ◽

Road Transportation ◽

Passenger Car ◽

Engine Efficiency ◽

Driving Conditions

Organic Rankine Cycle (ORC) power plants are characterized by high efficiency and flexibility, as a result of a high degree of maturity. These systems are particularly suited for recovering energy from low temperature heat sources, such as exhaust heat from other plants. Despite ORCs having been assumed to be appropriate for stationary power plants, since their layout, size and weight constraints are less stringent, they represent a possible solution for improving the efficiency of propulsion systems for road transportation. The present paper investigates an ORC system recovering heat from the exhaust gases of an internal combustion engine. A passenger car with a Diesel engine was tested over a Real Driving Emission (RDE) cycle. During the test exhaust gas mass flow rate and temperature have been measured, thus calculating the enthalpy stream content available as heat addition to ORC plant in actual driving conditions. Engine operating conditions during the test were discretized with a 10-point grid in the engine torque–speed plane. The ten discretized conditions were employed to evaluate the ORC power and the consequent engine efficiency increase in real driving conditions for the actual Rankine cycle. N-pentane (R601) was identified as the working fluid for ORC and R134a was employed as reference fluid for comparison purposes. The achievable power from the ORC system was calculated to be between 0.2 and 1.3 kW, with 13% system efficiency. The engine efficiency increment ranged from 2.0% to 7.5%, with an average efficiency increment of 4.6% over the RDE test.

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Analysis of a Diesel Engine Exhaust Manifold

Volume 9: Mechanics of Solids, Structures and Fluids ◽

10.1115/imece2014-37606 ◽

2014 ◽

Author(s):

Yiran Yang ◽

Miao He ◽

Masoud Mojtahed

Keyword(s):

Diesel Engine ◽

Stress Distribution ◽

Operating Conditions ◽

Exhaust Manifold ◽

Ansys Software ◽

Engine Exhaust ◽

Diesel Engine Exhaust ◽

Engine Efficiency ◽

Key Factor ◽

Coolant Velocity

The exhaust manifold is an essential component of an engine, which has become increasingly important because of innovations in the industry. Thus, the efficiency of an exhaust manifold is a key factor in overall engine efficiency. In operating conditions, there are many factors that may influence the performance of an exhaust manifold, such as temperature, pressure, wall thickness, coolant velocity, etc. A manufacturer of diesel engine’s exhaust manifolds was interested in investigating the performance of its manifolds. This paper describes the method of analysis and results obtained by Fluent and ANSYS software. The purpose of the project is to analyze the stress distribution and locate the areas most prone to failure.

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Development of in-use engine speed/torque heat maps across multiple heavy-duty commercial vehicle vocations

International Journal of Engine Research ◽

10.1177/14680874211029905 ◽

2021 ◽

pp. 146808742110299

Author(s):

Chen Zhang ◽

Kenneth Kelly ◽

Andrew Kotz ◽

Eric Miller

Keyword(s):

Operating Conditions ◽

Sweet Spot ◽

Heavy Duty ◽

Heat Maps ◽

Reduced Order ◽

Engine Efficiency ◽

Dna Database ◽

Cng Engine ◽

Operating Points ◽

Transit Bus

The U.S. Department of Energy (DOE) established the SuperTruck program with the goal of achieving brake thermal efficiency (BTE) greater than or equal to 55% as demonstrated in an operational heavy-duty (HD) diesel engine at a 65-miles-per-hour (mph) cruise point. Beyond the line-haul application, HD engines operate in a wide range of speed and torque conditions that are unlikely to yield the same efficiency under real-world operation. Thereby, the in-use engine heat maps described in this paper are a valuable tool to illustrate whether the engine-efficiency “sweet spot” matches the most frequent operating conditions. In this study, NREL developed engine heat maps to quantify the important operating points for various vocations using our Fleet DNA database of commercial fleet vehicle operations data. These heat maps clearly show that high-frequency operating points vary significantly according to vehicle vocation, while only a few of them match the sweet spot. Beyond the illustration, engine in-use heat maps can also be leveraged to build up reduced-order engine-efficiency models, needed by many rapid powertrain simulations. As case studies, nine reduced-order models – including line-haul truck, transfer truck, transit bus, transit bus with compressed natural gas (CNG) engine, drayage, refuse pickup, local delivery, utility truck, and school bus with CNG engine – using a trust-region reflective algorithm to fit the on-road data extracted based on the engine in-use heat maps.

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Control-oriented modelling of combustion phasing for a fuel-flexible spark-ignited engine with variable valve timing

International Journal of Engine Research ◽

10.1177/1468087412439019 ◽

2012 ◽

Vol 13 (5) ◽

pp. 448-463 ◽

Cited By ~ 6

Author(s):

Carrie M Hall ◽

Gregory M Shaver ◽

Jonathan Chauvin ◽

Nicolas Petit

Keyword(s):

Spark Ignition ◽

Operating Conditions ◽

Variable Valve Timing ◽

Valve Timing ◽

Real Time Control ◽

Engine Efficiency ◽

Time Control ◽

Spark Timing ◽

Variable Valve ◽

The Impact

In an effort to reduce dependence on petroleum-based fuels and increase engine efficiency, fuel-flexible engines with advanced technologies, including variable valve timing, are being developed. Fuel-flexible spark-ignition engines permit the increased use of ethanol–gasoline blends. Ethanol, an alternative to petroleum-based gasoline, is a renewable fuel, which has the added advantage of improving performance in operating regions that are typically knock limited due to the higher octane rating of ethanol. Furthermore, many modern engines are also being equipped with variable valve timing, a technology that can increase engine efficiency by reducing pumping losses. Through control of valve timings, particularly the amount of positive valve overlap, the quantity of burned gas in the engine cylinder can be altered, eliminating the need for intake throttling at many operating points. However, the presence of elevated levels of in-cylinder burned gas and ethanol fuel can have a significant impact on the combustion timing, such that capturing these effects is essential if the combustion phasing is to be properly controlled. This paper outlines a physically based model capable of capturing the impact of the ethanol blend ratio, burned gas fraction, spark timing and operating conditions on combustion timing. Since efficiency is typically tied to an optimal CA50 (crank angle when 50% of fuel is burned), this model is designed to provide accurate estimates of CA50 that can be used for real-time control efforts – allowing the CA50 to be adjusted to its optimal value despite changes in ethanol blend and burned gas fraction, as well as the variations in engine thermodynamic conditions that may occur during transients. The proposed control-oriented model was extensively validated at over 500 points across the engine operating range for four blends of gasoline and ethanol. Furthermore, the model was utilized to determine the impact of ethanol blend and burned gas fraction on the CA50, as well as their impact on the optimal spark timing. This study indicated that the burned gas fraction could change the optimal spark timing by over 20° at some operating conditions and that ethanol content could further affect the optimal spark timing by up to 6°. Leveraging the model in this manner provides direct evidence that accounting for the impact of these two inputs is critical for proper spark-ignition timing control.

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