THE IMPACT OF WATER INJECTION ON SPARK IGNITION ENGINE PERFORMANCE UNDER HIGH LOAD OPERATION PDF Download

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Languages : en
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Abstract : An experimental effort has been completed in which water injection was investigated as a means of enabling increases in engine output and high load efficiency. Water was injected into the intake port of a direct fuel injected, 4-cylinder, boosted engine with dual independent variable valve timing. The water was shown to increase volumetric efficiency and decrease the onset of knock which in turn enable more optimal combustion phasing. Both of these affects resulted increases in load of up to 5.5% at the same manifold pressure as the baseline case. The advancement of combustion phasing, combined with elimination of fuel enrichment resulted in an increase in full load thermal efficiency of up to 35%. Analysis is provided around these affects, as well as the phase transformation of water throughout the engine cycle.

Author: Hua Zhao
Publisher: CRC Press
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 562

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Homogeneous charge compression ignition (HCCI)/controlled auto-ignition (CAI) has emerged as one of the most promising engine technologies with the potential to combine fuel efficiency and improved emissions performance, offering reduced nitrous oxides and particulate matter alongside efficiency comparable with modern diesel engines. Despite the considerable advantages, its operational range is rather limited and controlling the combustion (timing of ignition and rate of energy release) is still an area of on-going research. Commercial applications are, however, close to reality. HCCI a.

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Languages : en
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Abstract : Natural gas has been gaining popularity as an alternative fuel due to its high availability, low CO2 emissions, and low cost. In this experimental study, water injection's impact on medium and heavy-duty engine operation fueled by natural gas and pilot diesel injection for ignition was studied under stochiometric operation for use with a three-way catalytic converter to meet criteria emissions for off-road power generation. To retain high efficiencies, a high compression ratio of 17.3:1 was used. Maintaining stoichiometric operation with a high compression ratio leads to combustion knock, pre-ignition, and high NOx formation. Conventionally, cooled EGR can be used to reduce NOx, but results in increased soot and does not eliminate combustion knock and pre-ignition. As an alternative to EGR this work utilized port injected water to provide on demand charge cooling, successfully reducing both NOx and soot while enabling high-load operation. A combination of both high and low speeds and loads were tested to study the impact of water injection on the emissions and performance of the natural gas, diesel-pilot engine. Additionally, water injections impact on diesel only operation was tested to provide comparison metrics and aid in a better understanding of the mechanisms at work when injecting water in an internal combustion engine. At full load, 16.8 bar BMEP, it was found that a water to fuel ratio of 0.5:1 was sufficient to enabling the knock free operation without significant increase in combustion duration or instability where operating at this load without water resulted in pre-ignition. Increasing the water to fuel ratio to 1:1 enabled a 21 bar BMEP load. At 12.5 bar BMEP, the NOx emission was reduced from 13.5 g/kwh to 7.2 g/kwh with a water to fuel mass ratio of 1.5:1. In addition to solving the high NOx and pre-ignition problem, a water to fuel ratio of 2.5:1 at 16.8 bar BMEP also decreased the soot content in the exhaust by a factor of 3.5 with only a small penalty in efficiency, decreasing break thermal efficiency from 41 to 40%.

Author: Rakesh Kumar Maurya
Publisher: Springer
ISBN: 3030119548
Category : Technology & Engineering
Languages : en
Pages : 616

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This book deals with in-cylinder pressure measurement and its post-processing for combustion quality analysis of conventional and advanced reciprocating engines. It offers insight into knocking and combustion stability analysis techniques and algorithms in SI, CI, and LTC engines, and places special emphasis on the digital signal processing of in-cylinder pressure signal for online and offline applications. The text gives a detailed description on sensors for combustion measurement, data acquisition, and methods for estimation of performance and combustion parameters. The information provided in this book enhances readers’ basic knowledge of engine combustion diagnostics and serves as a comprehensive, ready reference for a broad audience including graduate students, course instructors, researchers, and practicing engineers in the automotive, oil and other industries concerned with internal combustion engines.

Author: National Research Council
Publisher: National Academies Press
ISBN: 0309216389
Category : Science
Languages : en
Pages : 373

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Various combinations of commercially available technologies could greatly reduce fuel consumption in passenger cars, sport-utility vehicles, minivans, and other light-duty vehicles without compromising vehicle performance or safety. Assessment of Technologies for Improving Light Duty Vehicle Fuel Economy estimates the potential fuel savings and costs to consumers of available technology combinations for three types of engines: spark-ignition gasoline, compression-ignition diesel, and hybrid. According to its estimates, adopting the full combination of improved technologies in medium and large cars and pickup trucks with spark-ignition engines could reduce fuel consumption by 29 percent at an additional cost of $2,200 to the consumer. Replacing spark-ignition engines with diesel engines and components would yield fuel savings of about 37 percent at an added cost of approximately $5,900 per vehicle, and replacing spark-ignition engines with hybrid engines and components would reduce fuel consumption by 43 percent at an increase of $6,000 per vehicle. The book focuses on fuel consumption-the amount of fuel consumed in a given driving distance-because energy savings are directly related to the amount of fuel used. In contrast, fuel economy measures how far a vehicle will travel with a gallon of fuel. Because fuel consumption data indicate money saved on fuel purchases and reductions in carbon dioxide emissions, the book finds that vehicle stickers should provide consumers with fuel consumption data in addition to fuel economy information.

Author: H Zhao
Publisher: Elsevier
ISBN: 1845697324
Category : Technology & Engineering
Languages : en
Pages : 325

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Direct injection enables precise control of the fuel/air mixture so that engines can be tuned for improved power and fuel economy, but ongoing research challenges remain in improving the technology for commercial applications. As fuel prices escalate DI engines are expected to gain in popularity for automotive applications. This important book, in two volumes, reviews the science and technology of different types of DI combustion engines and their fuels. Volume 1 deals with direct injection gasoline and CNG engines, including history and essential principles, approaches to improved fuel economy, design, optimisation, optical techniques and their applications. Reviews key technologies for enhancing direct injection (DI) gasoline engines Examines approaches to improved fuel economy and lower emissions Discusses DI compressed natural gas (CNG) engines and biofuels

Author: Michael Günther
Publisher: Springer
ISBN: 3319697609
Category : Technology & Engineering
Languages : en
Pages : 381

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The book includes the papers presented at the conference discussing approaches to prevent or reliably control knocking and other irregular combustion events. The majority of today’s highly efficient gasoline engines utilize downsizing. High mean pressures produce increased knocking, which frequently results in a reduction in the compression ratio at high specific powers. Beyond this, the phenomenon of pre-ignition has been linked to the rise in specific power in gasoline engines for many years. Charge-diluted concepts with high compression cause extreme knocking, potentially leading to catastrophic failure. The introduction of RDE legislation this year will further grow the requirements for combustion process development, as residual gas scavenging and enrichment to improve the knock limit will be legally restricted despite no relaxation of the need to reach the main center of heat release as early as possible. New solutions in thermodynamics and control engineering are urgently needed to further increase the efficiency of gasoline engines.

Author: National Research Council
Publisher: National Academies Press
ISBN: 0309373913
Category : Science
Languages : en
Pages : 812

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The light-duty vehicle fleet is expected to undergo substantial technological changes over the next several decades. New powertrain designs, alternative fuels, advanced materials and significant changes to the vehicle body are being driven by increasingly stringent fuel economy and greenhouse gas emission standards. By the end of the next decade, cars and light-duty trucks will be more fuel efficient, weigh less, emit less air pollutants, have more safety features, and will be more expensive to purchase relative to current vehicles. Though the gasoline-powered spark ignition engine will continue to be the dominant powertrain configuration even through 2030, such vehicles will be equipped with advanced technologies, materials, electronics and controls, and aerodynamics. And by 2030, the deployment of alternative methods to propel and fuel vehicles and alternative modes of transportation, including autonomous vehicles, will be well underway. What are these new technologies - how will they work, and will some technologies be more effective than others? Written to inform The United States Department of Transportation's National Highway Traffic Safety Administration (NHTSA) and Environmental Protection Agency (EPA) Corporate Average Fuel Economy (CAFE) and greenhouse gas (GHG) emission standards, this new report from the National Research Council is a technical evaluation of costs, benefits, and implementation issues of fuel reduction technologies for next-generation light-duty vehicles. Cost, Effectiveness, and Deployment of Fuel Economy Technologies for Light-Duty Vehicles estimates the cost, potential efficiency improvements, and barriers to commercial deployment of technologies that might be employed from 2020 to 2030. This report describes these promising technologies and makes recommendations for their inclusion on the list of technologies applicable for the 2017-2025 CAFE standards.

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ISBN:
Category :
Languages : en
Pages :

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Abstract : A production Kohler 8.5RES residential stand-by generator set (Genset) was selected as the platform for this study due to its availability, simplicity, and price point. The Genset consists of a spark ignited (SI) two cylinder vee style internal combustion engine (ICE) capable of running natural gas or propane fuel with a 8.5 kW generator connected directly to the engines crankshaft. This allows for electrical load to be applied to the generator which in turn loads the engine without the use of a conventional dynamometer. A water cooled fully adjustable electric resistive load bank allows for easy adjustment to the desired load point. The electrical power generated was measured to determine the ICE output power and calculate the fuel energy to electrical energy conversion efficiency. To allow for control of the engine while testing it was modified from its original carbureted form to a port fuel injected (PFI) configuration and the original fixed spark timing system was removed and replaced with a coil ignition system. An electronic throttle body (ETB) was fitted to allow adjustment to the incoming air flow. The cylinder heads were modified to allow for a production direct inject (DI) fuel injector which used to deliver water to the combustion chamber and an in cylinder pressure transducer for analysis of various combustion parameters. The genset and test cell were instrumented with low speed and high speed dataacquisition (DAQ) systems to monitor and capture data at the chosen operatingconditions. The high speed data captured by the DAQ was used in conjunction with anear real-time combustion analysis program which calculated and logged combustionparameters and allowed for optimization of spark timing at each test point. Low speed data including fuel consumption, air mass flow rat, water consumption, and electrical power generated along with other engine parameters were monitored and logged as well. The ICE was tested at three different compression ratios (CRs) by changing the pistons and then by removing material from the cylinder head to decrease the clearance volume. The CR that came from the engine supplier was the first to be tested, second a CR in the range of 10:1-11:1 was targeted, and the range of the third CR was 14:1-15:1. The exact values of the CRs tested were calculated once the modifications were complete and volume measurements could be made. The first CR tested was 8.5:1 which is what the engine comes with from the supplier, the second 10.75:1 after changing pistons, and the third 14.3:1 after removing material from the cylinder head. Baseline data was collected at the 8.5:1 CR using the factory the fuel and ignition system to be used for comparison. Once the fuel, spark, and ETB modifications were complete tests were conducted by varying the load from 0 kW to the maximum attainable load at each test condition in 1 kW increments while targeting a relative air-fuel ratio (lambda, λ) of 1.0 and a speed of 3600 rpm. Using the combustion analysis software the gross indicated mean effective pressure (IMEP) was maximized for each test by varying spark timing. Water was injected into the combustion chamber at water to fuel ratios (WFRs) of 0.38, 1.0, and 1.5 by mass. These WFRs were chosen by the sponsor; the lowest possible WFR was to be tested as well as the 1.0 and 1.5 ratios. The lowest value of 0.38 was determined by testing the mass flow rate of the water injectors at decreasing durations. It was found that at WFRs lower than 0.38 the mass of water injected varied due to the injector's response properties. The start of injection (SOI) for water was swept from 180 degrees before top dead center (℗ʻBTDC) to 40 ℗ʻBTDC on the compression stroke in 20℗ʻ increments at each load condition tested. Before water injection tests began, each load point was tested and optimized to obtain baselines to be used for comparison against the water injection results for each CR tested. For each test performed an analysis was conducted to determine the effects of water injection of net fuel conversion efficiency, coefficient of variation (COV) of IMEP, and heat release rate which are discussed in greater detail later in this paper. Fuel conversion efficiency was used to determine if the water increased or decreased the conversion from fuel energy to mechanical work and quantified how it was impacted. The stability of combustion was determined by using the IMEP coefficient of variance which is common practice in ICE analysis to see how the water effected the variance in IMEP from cycle to cycle. Lastly heat release data was used to determine if the burn rate and ignition delay was impacted with the presence of water. From this data trends were identified and conclusions drawn regarding the overall impact water injection has on combustion.

Author: Rinaldo J. Brun
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 20

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Summary: An investigation has been made of the effectiveness of water injection into the combustion end zone of a spark-ignition engine cylinder for the suppression of knock. Pressure-time recoreds obtained show that injection of water at 60° B.T.C. on the compression stroke at a water-fuel ratio of 0.3 rendered M-3 fuel as good as S-3 fuel from an antiknock consideration. The optimum crank angle for injection of water into the end zone was found to be critical. As the injection angle was increased beyond the optimum, the quantity of water required to suppress knock increased to 3.6 water-fuel ratio at 132° B.T.C. The water quantity could not be increased beyond 3.6 water-fuel ration because of injection-pump limitations; however, a further increase in the injection angle up to the earliest angle obtainable, which was 20° A.T.C. on the intake stroke, continuously increased the knock intensity. The engine operating conditions of the tests did not simulate those encountered in flight, especially with regard to the operating speed of 570 rpm. For this reason the results should only be regarded as of theoretical importance until further investigation has been made.