Download or read book Performance Improvement Study on High Horsepower Compression Ignition Diesel Engines in Mining Haul Trucks at High Altitude written by Michael S. Wise and published by . This book was released on 2016 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of High Altitude on High Speed Diesel Performance written by Terrence John Kurtzweil and published by . This book was released on 1949 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advances in Compression Ignition Natural Gas Diesel Dual Fuel Engines written by Hongsheng Guo and published by Frontiers Media SA. This book was released on 2021-03-23 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of Very High Pressure Fuel Injection for High BMEP DI Diesel Engine written by K. Rhee and published by . This book was released on 1999 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to help design a high-power-density (HPD) low-heat-rejection (LHR) high-injection-fuel (HIP) direct-injection compression-ignition engine (DI-CI, two main methods were employed: (1) engine performance analysis; and (2) in-cylinder imaging. In the performance analysis, a Cummins 903 engine was used. The range of air/fuel ratio studied was from 18-1 to over 35-1, the injection pressure investigated was as high as 30,625 psi (210 Mpa) under varied intake air temperature over 150 deg C. In the in-cylinder imaging, a separate optical single-cylinder Cummins 903 engine was used. A high-speed four-color IR digital imaging system was greatly improved during this contract period. New spectrometric methods were developed to simultaneously determine the distributions of temperature, water vapor and soot concentrations. In addition, a new data analysis and presentation method has been developed. The performance analysis results are reported in two parts: a preliminary report as included in Appendix-I and an additional set of results (Appendix-Ill). Some of the in-cylinder imaging results, which are now being captured by the improved 515 after incorporating with new electronic packages (designed and fabricated in our laboratory), are included with discussions.

Download or read book Review of Technology Available to the Underground Mining Industry for Control of Diesel Emissions written by George H. Schnakenberg and published by . This book was released on 2002 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Addressing the Challenges of Advanced Compression Ignition Strategies Using Optimization Techniques with Machine Learning written by Naga Krishna Chaitanya Kavuri and published by . This book was released on 2018 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced compression ignition strategies like reactivity controlled compression ignition (RCCI) and gasoline compression ignition (GCI) have received substantial interest over the past few years. This is due to their potential to achieve reduced emissions, and higher efficiency, relative to conventional diesel combustion. However, most of the benefits seen in past research from these strategies were demonstrated under mid-load conditions. For these strategies to be implemented practically, similar benefits must be demonstrated across the drive cycle. Two particularly challenging areas of operation are high-load-low-speed and low-load-high-speed. Very limited research has been done with advanced compression ignition strategies in these points of the engine operating map. The reason for this is, at these operating conditions, there exists a mismatch between engine and chemistry time scales. The time scale mismatch results in either increased pressure rise rates or high levels of incomplete combustion, both of which make it difficult to operate. The work presented in this dissertation attempts to fill in these research gaps by using a combination of computational fluid dynamics modeling and genetic algorithm optimization. Initially, targeting high-load-low-speed conditions, a computational optimization study was performed at 20 bar indicated mean effective pressure and 1300 rev/min. with RCCI and GCI combustion strategies. The study was performed on a low compression ratio (12:1) piston with a "bathtub" geometry, since it was found to be well suited for high-load operation in earlier studies. The optima from the two combustion strategies were compared in terms of combustion characteristics, combustion control, and sensitivity to operating parameter variations. The results showed that both the strategies have similar combustion characteristics, including a two-stage heat release. A near top dead center injection initiated the combustion and its injection timing could be used to control the combustion phasing for both the strategies. Both the strategies required elevated levels of exhaust gas recirculation (EGR) (~55%) at a near stoichiometric global equivalence ratio to control the peak pressure rise rate. This resulted in high sensitivity to variations in EGR. To address this issue, high-load strategies at reduced EGR levels were investigated. A constraint analysis was performed using the optimization data to identify the constraints preventing operation at lower EGR levels. Results showed that operation at lower EGR rates was constrained by NOx emissions. Relaxing the NOx constraint enabled lower EGR operation with significant efficiency improvement. Allowing NOx emissions to increase to acceptable levels for selective catalytic reduction after treatment yielded an optimum at a moderate (~45%) level of EGR and a globally lean equivalence ratio of 0.8. This optimum case had near zero soot emissions and a higher net fluid efficiency (which accounted for the pumping loop work and the diesel exhaust fluid mass required to reduce the NOx emissions) compared to the earlier high EGR optima. Furthermore, the optimum case with NOx aftertreatment was compared with the high EGR optima in terms of combustion control and stability to operating condition fluctuations. The optimum with NOx aftertreatment retained the excellent combustion control seen with the high EGR optima, while reducing the sensitivity to operating parameter variations. The improved stability was attributed to operation at a reduced global equivalence ratio (from 0.93 to 0.8), which decreased the sensitivity to fluctuations in EGR rate. After addressing the issues at the high-load-low-speed operating condition, a low-load-high-speed operating point of 2 bar and 1800 rev/min. was simulated on the same engine used for the high-load studies. The results showed poor thermal efficiency for the low-load point. The poor efficiency was found to be due to an elevated level of incomplete combustion, which was a result of the low compression ratio piston used for the study. This result suggested that an optimum compression ratio should be identified considering the performance at the low-load and high-load conditions simultaneously. In addition, past optimization studies performed at low-load conditions have shown that the optimum bowl and injector design are very different compared to the high-load conditions. Accordingly, an optimization study was performed, considering performance at low- and high-load simultaneously. The optimum from the study was a stepped bowl geometry, with a compression ratio of 13.1:1, which resulted in a gross indicated efficiency of ~46% at both the loads. The study showed that the optimum design obtained from prioritizing one load deteriorates the performance at the other load. The results highlight the importance of considering multiple modes of the drive cycle simultaneously, when optimizing the engine design for advanced combustion strategies. It was shown that multiple modes of the drive cycle should be considered in optimization studies for advanced combustion strategies; however, the optimization with just two operating points took three months to complete. To consider all the modes of a drive cycle in the optimization, the computational time must be reduced. To address this issue, machine learning through Gaussian process regression was coupled with a genetic algorithm optimization to speed up the optimization process. Including machine learning within the optimization process reduced the computational time of optimization by 62%. The optimization process was further improved by using the Gaussian process regression model to check for the sensitivity of the designs to operating parameter variations during the optimization. The approach was tested with existing optimization data and it was shown that adding the stability check resulted in a reliable and stable optimum solution.

Download or read book Ignition Delay at Various High Pressures An Experimental Study written by Ritu Gaur and published by GRIN Verlag. This book was released on 2019-11-13 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research Paper (postgraduate) from the year 2019 in the subject Engineering - Chemical Engineering, , course: M.TECH, language: English, abstract: This work is an experimental study for the measurement of ignition delay characteristics of burning fuel sprays in cylindrical combustion chambers. It is carried out on hot air and high pressure. The objective of the study is to investigation the effect of hot air temperature and a well as high pressure on ignition delay of diesel fuel sprays. The effect of blending of n-Pentane with pure diesel was investigated. An experimental set up was design for this purpose with the emphasis on optical method for measurement of ignition delay at various pressures. The results presented here show that ignition delay of diesel fuel spray decreases with increase in the temperature and pressure of hot air. Results also show the effect of methyl group being more dominant at low ignition temperatures and that of alkyl group being more dominant at higher temperature. Blending of n-pentane with diesel fuel, increase its ignition delay at low ignition temperatures. However, as the concentration of blending fuel was increased beyond 30%, the ignition temperature increase. Ignition temperature for 40% pentane blends is much higher that the pure diesel.

Download or read book Analysis and Performance of a Conventional High Speed Compression ignition Engine Adapted to Gas Fuel Utilization written by Lester Robert Jones and published by . This book was released on 1948 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book OPTIMIZATION AND COMPARISON OF OVER EXPANDED AND OTHER HIGH EFFICIENCY FOUR STROKE SPARK IGNITED BOOSTED ENGINES written by and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : Recent fuel economy and emission regulations are the major concern of the research and development of modern internal combustion engine. Such technologies include variable valve timing (VVT), direct injection (DI), turbocharging, downsizing, and over-expanded cycle are used by many manufacturers to improve engine fuel economy or increase power density. Current Atkinson cycle technology in the production engine is mainly realized by an advanced valvetrain system to reduce the effective compression ratio while maintaining the same expansion ratio. Another approach to realize over-expanded cycle engine is to utilize a multi-link cranktrain mechanism. Although the Atkinson cycle was originally patented in the 1880s, the research of the over-expanded cycle engine realized by a multi-link cranktrain design is incomplete. This study focuses on the investigation of over-expanded engine realized by a cranktrain with a multi-link mechanism. The multi-link mechanism of cranktrain was developed and simulated with the constraints of packaging and match the same specification as the baseline engine including compression ratio, bore, and intake/compression stroke. This study also discusses adapting the cam profiles, cam phasing, and spark timing to compensate for the geometric characteristics difference between an Atkinson cycle engine and a conventional engine. The 1-D engine model was developed and calibrated in the commercial engine program, GT-Suite/GT-Power, based on the experimental results from a production four-cylinder spark-ignited engine (not over-expanded). The simulations of multi-link over-expanded engine and high compression engine were realized by substituting the new cranktrain for the baseline cranktrain In this study, the investigation of the multi-link over-expanded engine included a series of operating conditions from light load to high load. The results were compared at the optimized condition between the baseline engine, multi-link over-expand engine, and high compression engine. At the light load condition, it was observed that the net indicated efficiency of the over-expanded engine was slightly improved based on the adjustment method. This study also investigated the operating condition of the baseline engine with knock constrained and exhaust temperature constrained conditions at medium to high load. With the optimization, the over-expanded cycle engine is less constrained than the baseline engine due to the reduced knock propensity and exhaust gas temperature resulting in the further improvement of net indicated efficiency. The study of the multi-link over-expanded cycle engine includes the comparison with the latest production high compression ratio engine, representing state-of-the-art high efficiency engine technologies. The net indicated efficiency of multi-link over-expanded engine is even better than the peak efficiency point of the high compression engine.

Download or read book The Modern Diesel written by Rudolf Carl Christian Diesel and published by . This book was released on 1941 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Preliminary Design and Analysis of an Advanced Heat rejection System for an Extreme Altitude Advanced Variable Cycle Diesel Engine Installed in a High altitude Advanced Research Platform written by and published by . This book was released on 1992 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Power Output Operation of RCCI Combustion written by and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A computational investigation of methods to extend the upper limit of power output of reactivity controlled compression ignition (RCCI) engines was performed. The study utilized two approaches. The first approach is to increase the engine speed while maintaining a medium load. The second approach is to operate at higher loads without changing the engine speed. Iso-octane and n-heptane were used to represent the low-reactivity fuel and high-reactivity fuel, respectively. A light-duty diesel engine was modeled for the high speed dual-fuel RCCI combustion study. With high-speed operation several benefits were identified. Firstly, the peak pressure rise rates (PPRR), both crank angle-based and time-based, were reduced compared to those with low-speed operation. Secondly, at high speed the NO formation residence time became short, leading to reduced NOx emissions. Lastly, a frictional penalty analysis of high-speed operation using the Chen-Flynn model was conducted, which showed only 0.5 bar FMEP increase compared to that at low-speed. These findings indicate that high-speed RCCI is a very promising path for high-power output operation. For the high-load operation study use of dual direct-injectors was explored in order to direct-inject both fuels. Analysis of the optimum injection strategy revealed two main physical mechanisms enabling high-load operation with dual direct-injectors. The first exploited local evaporative cooling from the iso-octane injection, which delayed the iso-octane ignition. The second mechanism was related to the shorter chemical residence time of the iso-octane due to its late delivery into the cylinder. It was also noted that n-heptane's role as an ignition source could not be achieved with just iso-octane. Finally, the co-axial injector location assumption was removed by using an actual dual-injector layout. Unlike results with the co-axial injector design, the actual dual-injector layout exhibited soot and CO emission problems. In order to attempt to accommodate off-center injector locations, various injector hole patterns were tested. Although these unconventional injector hole patterns improved the emissions, it is concluded that the development of a co-axial dual-fuel injector is imperative in order to achieve clean RCCI combustion at high load.

Download or read book Exploration of Combustion Strategies for High efficiency Extreme compression Engines written by Mr. Matthew Neil Svrcek and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Increasing the compression ratio of an internal combustion engine to 100:1 or greater could potentially enable efficiencies greater than 60%. Understanding and managing the combustion process is a critical component to achieving this in practice. This thesis explores strategies for combustion at extreme compression ratios. First, the setup of a free-piston device capable of operating at 100:1 compression ratio is described. Initial performance results are reported for air-only experiments. Diesel-style combustion was the first approach taken, as it provides facile ignition phasing. Results are reported from initial lean Diesel combustion experiments at compression ratios ranging from 30 to 100:1. Indicated efficiency peaked at 60% for these experiments. To further understand Diesel-style combustion at extreme compression ratios, a study of Diesel sprays in the extreme compression apparatus was performed. The setup of a combined schlieren and direct luminosity imaging system with full-bore optical access is described. Spray penetration, dispersion, liquid length, and ignition delay are reported for combusting and non-combusting sprays. Compression ratios for these experiments ranged from 30 to 100:1. Spray behavior followed expected trends as a function of primary variables such as gas density. However, rapidly varying gas density from the free-piston profile impacts the spray penetration. Furthermore, at the highest compression ratios in-cylinder fluid motion dramatically affects the spray behavior, enabled by the low ratio of fuel to gas density. Systems added to the extreme compression apparatus to measure gaseous and particulate emissions are described. Emissions measurements from Diesel-style combustion of isooctane at 35:1 compression ratio are reported, to provide a reference case at conditions similar to conventional engines. Emissions were similar to those from production Diesel engines, with the exception that soot, HC, and CO increased more rapidly with equivalence ratio in the present study. Results from experiments with Diesel combustion up to 100:1 compression ratio are also reported. The combustion efficiency was 99% up to 100:1 compression ratio, and HC, CO and soot emissions were low. Emissions of NOx were 5 times higher at 100:1 than at 35:1, and would require aftertreatment. Stoichiometric, premixed-charge combustion enables the use of a three-way catalyst and produces low soot levels. Using this approach at extreme compression ratios requires delaying autoignition until the minimum volume is reached. Options for control of autoignition are discussed, and gas cooling is identified as the most effective. Pre-refrigeration, intercooling, and evaporation of a liquid are modeled and shown to effectively achieve the desired ignition timing at 100:1 compression ratio, without impacting the overall engine efficiency. Experimental results are reported for premixed methane-air combustion with intercooling control of autoignition, for 0.96 to 1.04 equivalence ratio and 35 to 90:1 effective compression ratio. The gas cooling requirement for autoignition control was higher than predicted by the models, but still within practical reach. The indicated efficiency peaked at 57%. Emissions levels from these experiments were similar to stoichiometric spark-ignited natural gas engines reported in the literature, and indicate that a three-way catalyst could be successfully used even at extreme compression ratios. Results are also reported for water injection control of autoignition. Autoignition was successfully controlled up to 60:1 effective compression ratio, but the mass of water required was an order of magnitude higher than predicted. This is shown to result from practical limitations of the current water injector setup.

Download or read book Analysis of Homogeneous Charge Compression Ignition Engine with Emphasis on Combustion Timing and Reaction Rate written by Arunim Bhattacharya and published by . This book was released on 2017 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: HCCI engines are a class of engines which use high compression ratio to ignite a charge of air-fuel mixture, essentially eliminating the need for spark plugs. This contrasts with diesel engines (although HCCI can be used for diesel engines) where the fuel is injected near the top dead center of the compression stroke regime. Gasoline HCCI engines are of significance because, it attempts to improve the characteristics of the engine for example the thermal efficiency. High compression ratio comes with higher thermal efficiency, yet the peak temperature remains low enough to have low production rates of harmful oxides of nitrogen and formation of soot. However, there are certain challenges associated with such type of engine, one of which and perhaps the most important of all is how to control the combustion rate. Flow dynamics and chemical-kinetics analysis, is essential to predict combustion timing, duration, and rate. The objective of this study is to analyze a HCCI engine using, simulation analysis models including a three-dimensional CFD simulation model. Simulation analysis is carried out using a generic HCCI engine, initially with simplified chemical kinetics, and then using detailed chemical kinetics and using RANS turbulence CFD model. A sensitivity analysis of the effect of RPM on the combustion time, burn duration, heat release, efficiency and emission concentration are carried out.

Download or read book Boosted Performance of a Compression ignition Engine with a Displacer Piston written by Charles S. Moore and published by . This book was released on 1936 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Performance tests were made using a rectangular displacer arranged so that the combustion air was forced through equal passages at either end of the displacer into the vertical-disk combustion chamber of a single-cylinder, four-stroke-cycle compression-ignition test engine. After making tests to determine optimum displacer height, shape, and fuel-spray arrangement, engine performance tests were made at 1,500 and 2,000 r.p.m. for a range of boost pressures from zero to 20 inches of mercury and for maximum cylinder pressures up to 1,150 pounds per square inch. The engine operation for boosted conditions was very smooth, ther being no combustion shock even at the highest maximum cylinder pressures. Indicated mean effective pressures of 240 pounds per square inch for fuel consumptions of 0.39 pound per horsepower-hour have been readily reproduced during routine testing at 2,000 r.p.m. at a boost pressure of 20 inches of mercury.

Download or read book A Study of the Performance of a Compression ignition Engine with Modifications to Enhance Atomization Using Alternative Fuels written by Randolph Cedric Bunt and published by . This book was released on 1982 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book COMBUSTION EMISSIONS AND PERFORMANCE OPTIMIZATION IN A DI PFI RCCI DIESEL NATURAL GAS TURBOCHARGED ENGINE written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : Diesel-NG fuel blends are increasingly being used in Reactivity Controlled Compression Ignition (RCCI) applications due to high Brake Thermal Efficiency (BTE), low NOx and PM emissions. But it also has a few disadvantages such as high HC and CO emission and relatively low Exhaust Gas Temperature (EGT). This leads to find out the optimum tradeoff between emissions to meet the regulation and also investigate the cost of operation and find out the minimum liquid consumption (fuel + urea) in RCCI mode. A Cost Function (CF) including Brake Specific Fuel Consumption (BSFC) and Brake Specific Urea Consumption (BSUC) is considered and minimized in this study. This optimization helped to investigate the optimum input parameters between 3 to 12 bar IMEP at 1500 RPM engine speed. This study has been done while all the population in optimization process meet the Tier 3 Bin 20 emission regulations. To increase the number of data points in this optimization, a mathematical (numerical) model is developed to predict (or assess) the Diesel-NG RCCI data. Single fuel diesel only mode is also considered in this optimization, since high BTE of RCCI is limited to medium and high load operating conditions and due to the high HC and low EGT, RCCI may not be an ideal combustion mode at low loads. Parametric models have been developed and validated using experimental data on a light duty 1.9L inline 4 cylinder Compression Ignition (CI) engine as a function of independent input variables including, first and second Start of Injection (SOI1 and SOI2), Manifold Absolute Pressure (MAP), lambda, Exhaust Gas Recirculation (EGR) and Blending Ratio (BR), and validated using RCCI experimental data. In these models, selected emissions - including HC, CO, PM and NOx-, Exhaust Gas Temperature (EGT) and BSFC were computed using correlations as functions of independent input variables. The computed EGT were then used to estimate the Selective Catalyst Reduction (SCR) and Diesel Oxidation Catalyst (DOC) efficiencies to assess the emission data for different input variables by considering after-treatment system to see if they meet the tailpipe emission regulation. Running the engine with this calibrated input parameters not only meet the Tier 3 Bin 20 EPA standard, but also minimized the cost of operation in RCCI mode within 3 to 12 bar IMEP engine load at 1500 RPM engine speed.