Browse Topic: Natural gas

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Fuels in Ground Support Equipment (Other Than Gasoline or Diesel)AIR5373A (Current)9/23/2020
This SAE Aerospace Information Report (AIR) is intended as a source of comparative information and is subject to change to keep pace with experience and technical advances. This document describes currently used fuels and fuels which may be used in the future. Conventional gasoline and diesel fuels are intentionally omitted from this document.
AGE-3 Aircraft Ground Support Equipment Committee
Aging of a Multi-Hole Diesel Injector and Its Effect on the Rate of Injection2020-01-08294/14/2020
In order to comply with the increasingly restrictive limits of emissions and fuel consumption, researches are focusing on improving the efficiency of combustion engines. In this area, the aging of the injector and its effect on the injection development is not entirely analyzed. In this work, the rate of injection of a diesel injector at different stages of its lifetime is analyzed. To this end, a multi-hole piezoelectric injector was employed, comparing the injection rate measured at the beginning of its lifetime to the rate provided by the injector after aging, maintaining the same boundary conditions in both measurements. Injection pressures up to 200 MPa were used throughout the experiments. The results showed that the steady-state rate of injection was lower after the injector aged. Furthermore, the injector took a longer time to close the needle and end the injection, in comparison with the measurements done at earlier stages of its lifetime. To explain this phenomenon, measurements of momentum flux for each injector hole were done, and results showed that two holes were partially obstructed. Thus, the presence of coking in the nozzle of the injector was considered as the cause of the differences between stages seen in the rate of injection. In this sense, a reduction of the effective outlet holes area due to deposits would restrict the flow rate. Moreover, the pressure in the nozzle due to the contained fuel is extended, leading to a longer time required by the needle to descend and end the injection. Then, aging of the injector was attributed to deposits in the nozzle holes. This phenomenon could result in an inhomogeneous spray distribution, which should be taken into account when designing the combustion process.
Payri, Raul, Salvador, Francisco Javier, Gimeno, Jaime, Montiel, Tomas
Performance of a Printed Bimetallic (Stainless Steel and Bronze) Engine Head Operating under Stoichiometric and Lean Spark Ignited (SI) Combustion of Natural Gas2020-01-07704/14/2020
Additive manufacturing was used to fabricate a head for an automotive-scale single-cylinder engine operating on natural gas. The head was consisted of a bimetallic composition of stainless steel and bronze. The engine performance using the bimetallic head was compared against the stock cast iron head. The heads were tested at two speeds (1200 and 1800 rpm), two brake mean effective pressures (6 and 10 bar), and two equivalence ratios (0.7 and 1.0). The bimetallic head showed good durability over the test and produced equivalent efficiencies, exhaust temperatures, and heat rejection to the coolant to the stock head. Higher combustion temperatures and advanced combustion phasing resulted from use with the bimetallic head. The implication is that with optimization of the valve timing, an efficiency benefit may be realized with the bimetallic head.
Kass, Michael, Biruduganti, Munidhar, Kaul, Brian, Storey, John, Longman, Douglas, Elliott, Amelia, Siddel, Derek
Measurement of Fuel Distribution in a Small PFI Spark-Ignition Engine Using Tracer PLIF2020-01-07864/14/2020
The distribution of fuel-air mixture inside the engine cylinder strongly influences the combustion process. Planar laser-induced fluorescence (PLIF) is commonly used for fuel distribution measurement, however, it is mostly reported on moderate- to large-sized engines. In the present work, PLIF is applied to measure the fuel distribution inside the cylinder of a small, four-stroke, port-fuel-injection (PFI), spark-ignition engine with displacement volume of 110 cm3. Iso-octane was used as the base fuel, and 3-pentanone (15% by volume) was added as a fluorescent tracer in the base fuel. The effect of equivalence ratio, considering ϕ = 1.2, 1.0, and 0.8, on in-cylinder fuel distribution was studied with low throttle opening of 25% at 1200 rpm. PLIF images were recorded at different crank angle degrees during both intake and compression strokes over a swirl measurement plane located at the TDC position. It was found that the fuel stratification was present from intake to even late compression. Also, no significant change in fuel distribution patterns was noted at different crank angle degrees for a given operating condition. Instantaneous PLIF images of the fuel distribution at 330 CAD during compression also showed a considerable variation from one cycle to the next. As expected, the fluorescence signal intensity was increased with the increase in equivalence ratio. Results also showed that the fuel distribution was much more noticeable near the diametrically opposite location to the spark plug on the tested engine, and continued to exist till late compression (i.e. 330 CAD).
Garg, Shubham, Mittal, Mayank, Sahu, Srikrishna, Lakshminarasimhan, V
Development of Dual Fuel Engine Fueled with Used Cooking Oil Biodiesel and Ethanol-an Experimental Study on Performance and Combustion Characteristics2020-01-08034/14/2020
This paper investigates the performance and combustion characteristics of a compression ignition engine (CI engine) fueled with Used Cooking Oil Biodiesel (UCOB) and ethanol in dual fuel mode. In this study, UCOB was injected as the main fuel through a conventional mechanical fuel injection system. Various mass flow rates of ethanol were inducted as primary fuel through the engine intake manifold using a separate fuel injection system. Mass flow rates of ethanol were metered by an electronic control circuit. The engine test was conducted under different load conditions from no load to full load in a fully instrumented direct injection, water-cooled compression ignition engine. The results indicated that the dual fuel engine produced higher brake thermal efficiency, cylinder pressure, heat release rate with lower specific fuel consumption at a higher load condition. However, it was found that combustion characteristics improved marginally at the lower load conditions.
Velmurugan, Ramanathan, Mayakrishnan, Jaikumar, Palanimuthu, Vijayabalan, Nandagopal, Sasikumar, Elumalai, Sangeethkumar, Anaimuthu, Shridhar, Busireddy, Vamshidhar
Green Jet Fuel Additive Made from Acetone Plus LightTBMG-361733/1/2020
A domestically generated additive was made by taking biomass-derived acetone — common nail polish remover — and using light to upgrade it to higher-mass hydrocarbons. It can be blended with conventional jet fuel to fly while providing environmental benefits.
Layered Composite InsulationTBMG-361633/1/2020
NASA's Layered Composite Insulation (LCI) technology is an easy-to-use system that can benefit multiple industries that depend on regulation of low temperatures in equipment and products. The technology combines a unique layered cryogenic insulation system with specific manufacturing, packaging, wrapping, and rolling methods.
Experimental Comparison of Biogas and Natural Gas as Vibration, Emission, and Performance in a Diesel Engine Converted to a Dual Fuel04-13-01-00041/27/2020
Biogas, natural gas, and their usage in the diesel engine will be important in the future. For this purpose, the effects of biogas on engine performance, emissions, and engine vibrations of the diesel engines with dual fuel system are investigated in comparison with natural gas. It has also been included in evaluating the deformation of the engine oil due to hydrogen sulfide combustion reactions. In this study, a constant speed, naturally aspirated, and direct injection of the diesel engine with volume of 2.5 liter has been converted into a dual fuel system that can be included in gas fuels. In order to determine engine performance, exhaust emissions, engine vibration, and noise, the tests were carried out at load stages of 5, 10, 15, 20, and 25 kW and at a constant speed of 1500 rpm. The experiments were first performed in a mono operation condition of the conventional diesel fuel. Subsequently, tests were repeated under natural gas/diesel and biogas/diesel dual fuel operation conditions, respectively. As a result of the tests, it was observed that the vibration amount decreased and the noise emission was reduced by 3.5% in all stages where biogas was used as the main fuel. Depending on fuel or operation system change, no significant change was observed in cylinder block, cylinder heat, exhaust, and intake manifold temperature. The exhaust gas temperature is measured to be lower because of the carbon dioxide (CO2) content in the biogas. When approaching from the point view of engine emissions, it was determined that the carbon monoxide (CO) emission increased at all engine loads while a decrease of 50% in oxides of nitrogen (NOx) emission occurred.
Aytav, Emre, Koçar, Günnur, Teksan, Abdulhalik Emre
THE EFFECT OF BIODIESEL ON THE ELECTRICAL PROPERTIES OF AUTOMOTIVE ELASTOMERIC COMPOUNDS2019-36-03271/13/2020
The lack of electrical conductivity on materials, which are used in automotive fuel systems, can lead to electrostatic charges buildup in the components of such systems. This accumulation of energy can reach levels that exceed their capacity to withstand voltage surges, which considerably increases the risk of electrical discharges or sparks. Another important factor to consider is the conductivity of the commercially available fuels, such as biodiesel, which contributes to dissipate these charges to a proper grounding point in automobiles. From 2013, the diesel regulation in Brazil have changed and the levels of sulfur in the composition of diesel were reduced considerably, changing its natural characteristic of promoting electrostatic discharges, becoming more insulating. Taking into account the critical factors mentioned above, the SAE J1645 standard specifies the levels of conductivity and maximum electrostatic energy accumulation (ESD) that automotive materials must meet to avoid unintentional discharges on these systems and guarantee the integrity of the involved components and the safety of occupants. Thus, this work aims to analyze the effect of (bio)diesel on the electrical properties of a new elastomeric composition (PVC/NBR+) for fuel filler hoses. The findings present evidence that this new formulation has high performance in the dissipation of electrostatic charges and can meet the conductivity levels requested by SAE J1645, even in aging test with aggressive biodiosel.
Ângelo Aguiar, Rodrigo Polkowski, Almeida, Oberti, Gonçalves, Cristiane, Herbert, Cristiano, Santos, Helano, Souza, Jodalva
B-GAS: Conversion system to Internal Combustion Engine (Diesel) for using alternative energetic source for application in Agricultural Machinery2019-36-02351/13/2020
Fuel has a huge port in the operating costs of agribusiness, the increase on the price and the shortage of this energy resource has a direct impact on agricultural production costs. In this context, regions that are farther from refineries and lack the presence of fuel distribution centers tend to suffer more from the availability and cost of this resource. Economically speaking, agribusiness has a prominent position in the national scenery. The world fuel source had an evolution from the predominance of solid fuels to the current age of liquid fuels derived from petroleum and seeing the future and growing age of gas fuels as the predecessor stage of electric vehicles in some markets. Thereby, agricultural organic waste has the potential to generate an alternative energy, clean and ecological matrix, also reducing the emission of polluting gases, soil, groundwater, rivers and weir are still prevented, and the release of greenhouse gases in the atmosphere, such as methane and carbon dioxide. In Brazil, animal waste is normally used for the generation of biofuel, and only 14% of it used in automobiles. Thus, biogas has been studied as a promising energy matrix because it is less polluting and renewable to mitigate the damaging effects of fossil fuels. However, it is highest limitation is the low development of adaptation for Diesel engines, whereupon the project in question is aimed, of which purpose is to develop solutions for existing Diesel engines while maintaining the performance and durability, reducing the dependence of fossil fuels and allowing the use of alternative and cheaper energy sources, produced by the agriculturalists who have space and infrastructure to produce their own fuel, making it self-sustaining. Thus, the development of the project will be guided by the injection of the biogas in the intake manifold in a stoichiometric ratio of air / fuel according to operational necessity, while the biodiesel injected directly into the combustion chamber will be of utmost importance for the start of combustion as pilot flame, since the biogas is unable to combust only with the compression of the cylinder.
da Silva, Giovana Queiroz, Gomes, Cléber Willian, dos Santos, Guilherme Bugatti, Nunes da Costa, Paulo Eduardo Wey, Talib Soares, Pedro Augusto, Raduan, Renato Zerbinatti, Gomes, Vinícius Trento
Effect of Alternative Fuels on Marine Engine Performance2019-01-223012/19/2019
Marine transportation sector is highly dependent on fossil-based energy carriers. Decarbonization of shipping can be accomplished by implementing biobunkers into an existing maritime fuel supply chain. However, there are many compatibility issues when blending new biocomponents with their fossil-based counterparts. Thus, it is of high importance to predict the effect of fuel properties on marine engine performance, especially for new fuel blends. In the given work, possible future solutions concentrated on liquid fuels are taken into account. Under consideration are such fuels as biodiesel (FAME), hydrotreated vegetable oil (HVO), straight vegetable oil (SVO), pyrolysis oil, biocrude, and methanol. Knowledge about the behavior of new fuel in an existing engine is notably important for decision makers and fuel producers. Hence, the main goal of the present work is to create a model, which can predict the engine performance from the end-user perspective. For the purpose of modeling, only the latest research on marine fuels is taken into account. In the current approach, results from a representative measurement set-up are compared in order to create a uniform model. As a result, all the provided data are expressed in relative changes in reference to standard marine fuel – heavy fuel oil (HFO). The modeling Is performed by means of multilinear regression and accuracy of the model is relatively high, with a coefficient of determination over 0.9. The outcomes provide a prediction of final engine performance for the specified fuel blend. Knowing the final properties of fuel (such as calorific value, density, viscosity), it is attainable to estimate fuel consumption, carbon dioxide emissions and determine possible fuel compatibility issues. Moreover, the model enables estimation of carbon dioxide (CO2) tailpipe emissions, which should be included in the whole Life Cycle Analysis (LCA) while assessing the renewability index of the fuel.
Wojcieszyk, Michal, Kroyan, Yuri, Larmi, Martti, Kaario, Ossi, Zenger, Kai
Effects of Piston Bowl Diameter on Combustion Characteristics of a Natural gas/Diesel Dual Fuel Engine2019-01-217312/19/2019
Natural gas/diesel dual fuel engines have potential for a high thermal efficiency and low NOx emissions. However, they have the disadvantages of high unburned species emissions and lower thermal efficiencies at low loads (at low equivalence ratio). A way to solve this problem is to properly distribute the pilot fuel vapor in a natural-gas premixture. The combustion chamber geometry affects the combustion process since it influences the distribution of the pilot fuel vapor. This study investigates the influence of injection conditions and the piston bowl geometry on the performance and emissions of a dual fuel engine. Experiments were carried out using two pistons with different bowl diameters, 52 mm and 58 mm, at single-and two-stage diesel-fuel injection. The results show that the larger bowl provides lower hydrocarbon emissions at a lower equivalence ratio in the case of single-stage injection. For two-stage injection, the influence of the bowl diameter depends on the timing of the first injection. To elucidate the effects of pilot fuel distribution, computational fluid dynamics (CFD) calculations were conducted for non-reacting pilot fuel sprays under conditions equivalent to the experiments. As a result, the relative rich area of the pilot fuel in the case of the single injection in the large piston bowl do not impinge on the piston wall at the ignition timing of the experiment, which leads to higher heat release rate owing to the weak cooling effect.
Takizawa, Keigo, Tanaka, Hidetake, Horibe, Naoto, Ishiyama, Takuji, Sako, Takahiro
Research of Fuel Characteristic of Dimethyl ether / High Viscosity & Incombustible matter Blend for Marine Diesel Engine2019-01-222912/19/2019
Diesel engine has fuel combustion capability in various high density oil such as residual fuels or biofuels derived from fossil or living matter. But for commercial use, these fuels except bio diesel fuel (BDF) should be heated, separated and filtered by equipment and dosed or mixed with additive or distillate oil etc. before being supplied to the engine in order to improve combustibility. This study aims to illuminate fuel characteristic of blend contained woody pyrolysis oil (WPO) which is high viscosity and incombustible, and dimethyl ether (DME) whose emission of combustion has no soot particle. This paper describes thermo-physical property of neat WPO and the blend on the basis of the evaluation of fuel fluidity by measurement and calculation of viscosity. According to the result, it was confirmed that the fluidity of WPO was improved by mixing DME and the approximate viscosity expressions at any temperature of WPO and the blend were good accuracy.
MIHARA, Yu, KURO-OKA, Daiki, SHIRAHAMA, Tomoki, KUWAOKA, Kenta, SUZUKI, Takashi, ASANO, Ichiro, DAN, Tomohisa
Analysis on flow motion and combustion process in pre-chamber and main chamber for low-speed two-stroke dual-fuel engine2019-01-217512/19/2019
ABSTRACT Low-speed two-stroke dual-fuel engines has been paid more attention due to the energy efficiency design index and Tier III emissions limitations issued by International Marine Organization. Although the dual-fuel engines have strong merits on emissions reduction, which can reach the IMO Tier III without aftertreatment, the power output is much lower than that of diesel engines. Therefore, the dual-fuel engine is also needed to improve continuously. However, the mixing and combustion processes in the engine have not been fully understood. In this study, a 3D-CFD model of the dual-fuel engine was established using CONVERGE to explore the mixing and combustion processes. Locally embedding fine grids are considered at scavenging ports, natural gas injection ports, pre-chamber. The model was validated by experimental in-cylinder pressure. Then, the flow motion, mixing of natural gas and air, flow in pre-chamber, torch and combustion in main-chamber were analyzed based on swirl variation, flow velocity distribution, equivalence ratio distribution and torch propagation.
Liu, Long, Wu, Yue, Xiong, Qian, Liu, Teng
Effects of Engine Operating Condition and Fuel Property on Pre-Ignition Phenomenon in a Highly Boosted Premixed Natural Gas Engine2019-01-215412/19/2019
The stochastic pre-ignition phenomenon plays a vital role to limit the further increasing BMEP for natural gas engines. In this study, the pre-ignition propensities were examined in a highly boosted premixed natural gas engine by various engine loads and air/fuel ratios, as well as different methane number (MN) altered by hydrogen addition. A proper pre-ignition evaluation method was proposed referring to intake temperature. Moreover, the limits of in-cylinder temperature and pressure for the onset of pre-ignition were estimated. The results show that both higher IMEP and richer mixture conditions readily lead to pre-ignition. The significant increases of pre-ignition frequency and heavy-knocking pre-ignition cycle present with lowering MN.
Chen, Run, Kuboyama, Tatsuya, Moriyoshi, Yasuo, Yasueda, Shinji, Doyen, Valerie, Martin, Jean-Baptiste
1D Numerical and Experimental Investigations of an Ultralean Pre-Chamber Engine03-13-02-001211/19/2019
Abstract In recent years, lean-burn gasoline Spark-Ignition (SI) engines have been a major subject of investigations. With this solution, in fact, it is possible to simultaneously reduce NOx raw emissions and fuel consumption due to decreased heat losses, higher thermodynamic efficiency, and enhanced knock resistance. However, the real applicability of this technique is strongly limited by the increase in cyclic variation and the occurrence of misfire, which are typical for the combustion of homogeneous lean air/fuel mixtures. The employment of a Pre-Chamber (PC), in which the combustion begins before proceeding in the main combustion chamber, has already shown the capability of significantly extending the lean-burn limit. In this work, the potential of an ultralean PC SI engine for a decisive improvement of the thermal efficiency is presented by means of numerical and experimental analyses. The SI engine is experimentally investigated with and without the employment of the PC with the aim to analyze the real gain of this innovative combustion system. For both configurations, the engine is tested at various speeds, loads, and air-fuel ratios. A commercial gasoline fuel is directly injected into the Main Chamber (MC), while the PC is fed in a passive or active mode. Compressed Natural Gas (CNG) or Hydrogen (H2) is used in the actual case. A 1D model of the engine under study is implemented in a commercial modeling framework and is integrated with “in-house developed” sub-models for the simulation of the combustion and turbulence phenomena occurring in this unconventional engine. The numerical approach proves to reproduce the experimental data with good accuracy, without requiring any case-dependent tuning of the model constants. Both the numerical and experimental results show an improvement of the indicated thermal efficiency of the active PC, compared to the conventional ignition device, especially at high loads and low speeds. The injection of H2 into the PC leads to a significant benefit only with very lean mixtures. With the passive fueling of the PC, the lean-burn limit is less extended, with the consequent lower improvement potential for thermal efficiency.
Bozza, Fabio, De Bellis, Vincenzo, Tufano, Daniela, Malfi, Enrica, Müller, Christoph, Habermann, Knut
Influence of Addition of Ethanol into Non-Edible Biodiesel from Rice Bran Oil on the Properties and Performance - An Experimental Study in Direct Injection VCR Diesel Engine2019-28-016010/11/2019
Non-edible oil biodiesels and alcohols are the two major liquid fuel sources available to replace diesel to fuel compression ignition engine. This study is to investigate the solubility, properties and performance of biodiesel from non-edible rice bran oil and ethanol. Solubility test was conducted in three different temperatures 50C, 150C& room temperature (300C approximately). The stable blends were tested for essential properties such as energy content, cetane number, kinematic viscosity, heat of vaporisation, flash point and oxygen content as per ASTM standards. Biodiesel- ethanol blends containing 30% of ethanol was found stable up to 50C. This blend also met the minimum requirement with respect to properties to fuel compression ignition engine. These blends were tested in compression ignition engine for performance, combustion and emission characteristics in various load conditions under two compression ratios (17,1 & 18,1). Results showed that the compression ratio 18:1 was found suitable for the optimal blend. This blend produced brake thermal efficiency, peak incylinder pressure, peak heat release rate, hydrocarbon, carbon monoxide, and smoke similar to that of diesel. However, ignition delay & emission of oxides of nitrogen produced by this blend was found slightly higher compared to diesel.
Balasubramanian, Prabakaran, Shanmuga Sundaram, Padmanaba Sundar, Manoharan, Hemakumar
MISERLY POWER SYSTEMS19TOFHP10_0210/1/2019
Engineers push engine, transmission technologies to turn off fuel usage. Commercial-truck powertrains are doing more with less. Engine developers are adding features that reduce fuel consumption, saving owners money while helping fleets reduce emissions. Digital technologies continue to transform commercial trucking as powertrain providers devise new ways to eke more from each drop of fuel. Engines now adapt to road conditions, adjusting power and shutting down some or all of the cylinders as demands change. Electric fans and maintenance monitoring now are being used to help keep engines running at maximum efficiency while using less fuel. Design teams also are refining technologies like start-stop and cylinder deactivation, working to make them smooth enough that drivers barely notice the systems are adapting to the environment.
Costlow, Terry
CFD Investigation of the Effects of Gas’ Methane Number on the Performance of a Heavy-Duty Natural-Gas Spark-Ignition Engine2019-24-00089/9/2019
Natural gas (NG) is an alternative fuel for spark-ignition engines. In addition to its cleaner combustion, recent breakthroughs in drilling technologies increased its availability and lowered its cost. NG consists of mostly methane, but it also contains heavier hydrocarbons and inert diluents, the levels of which vary substantially with geographical source, time of the year and treatments applied during production or transportation. To investigate the effects of NG composition on engine performance and emissions, a 3D CFD model of a heavy-duty diesel engine retrofitted to NG spark ignition simulated lean-combustion engine operation at low speed and medium load conditions. The work investigated three NG blends with similar lower heating value (i.e., similar energy density) but different Methane Number (MN). The results indicated that a lower MN increased flame propagation speed and thus increased in-cylinder pressure and indicated mean effective pressure. In addition, a low MN increased the thermal efficiency despite the higher heat transfer to the surroundings. Also, a higher MN reduced the nitrogen-oxides emissions but increased unburned hydrocarbons (UHC) emissions. Moreover, while UHC emissions had a similar H/C ratio as the NG, there was no correlation between the carbon monoxide emissions and the fuel H/C ratio.
Ambrogi, Luca, Liu, Jinlong, Battistoni, Michele, Dumitrescu, Cosmin, Gasbarro, Lorenzo
Mobile, Dual-Comb Device for Methane Leak DetectionTBMG-351459/1/2019
Accurately detecting, locating, and quantifying leaks of methane — the main component of natural gas and a major fuel source worldwide — is critically important for both environmental and economic reasons. Unfortunately, traditional methods are slow, labor-intensive, limited to small coverage areas, and expensive to operate over time.
Methane Detector Sniffs Out LeaksTBMG-351569/1/2019
Methane is everywhere on Earth. It’s the main ingredient in the natural gas that powers heating, cooking, and electricity. It’s also a potent greenhouse gas. The presence of methane is also interesting for a different reason: because the biggest source of the gas on Earth is bacterial life. That means when NASA planetary scientists caught a glimpse of it on Mars, it merited a closer look.
Process Directly Converts Methane to MethanolTBMG-349348/1/2019
Methanol is a key feedstock for the production of chemicals, some of which are used to make products such as plastics, plywood, and paints. Methanol also can fuel vehicles or be reformed to produce high-grade hydrogen for fuel cells. The current method for producing methanol from methane- or coal-derived synthesis gas involves a multi-step process that is neither efficient nor economical in small-scale applications. As a result, methane emissions from oil wells — accounting for 210 billion cubic feet of natural gas annually — are being vented and flared, according to the U.S. Energy Information Administration.
Bullish on biomethane19TOFHP06_016/1/2019
The CEO of CNH Industrial says biomethane is cleaner path than electric, as Case demos the alt fuel in cool wheel-loader concept. Hybrid and electric powertrains were omnipresent at bauma 2019 in Munich, with several OEMs and engine manufacturers showcasing electrified machines in near-production form. But CNH Industrial bucked that trend, touting the many benefits of biomethane instead. “Everybody talks about electrification; however, we believe that on the on-highway side as well as in off-highway there is a ‘bridging technology’ that is here to stay-LNG and CNG (liquefied and compressed natural gas),” said Hubertus M. Mühlhäuser, CEO of CNH Industrial, which includes brands Case, New Holland, Iveco and FPT Industrial, among others.
Gehm, Ryan
Measurement Method for Radioactive MethaneTBMG-343845/1/2019
Anew method for measuring radioactive methane is an optical one based on spectroscopy. Previously, radioactive methane has been measured with accelerator mass spectrometry involving expensive machines. Optical measuring could be a cheaper and more agile method.
Performance, Fuel Economy, and Economic Assessment of a Combustion Concept Employing In-Cylinder Gasoline/Natural Gas Blending for Light-Duty Vehicle Applications03-12-03-00194/25/2019
In current production natural gas/gasoline bi-fuel vehicles, fuels are supplied via port fuel injection (PFI). Injecting a gaseous fuel in the intake port significantly reduces the volumetric efficiency and consequently torque as compared to gasoline. In addition to eliminating the volumetric efficiency challenge, direct injection (DI) of natural gas (NG) can enhance the in-cylinder flow, mixing, and combustion process resulting in improved efficiency and performance. A computational fluid dynamics (CFD) approach to model high-pressure gaseous injection was developed and validated against X-ray data from Argonne’s Advanced Photon Source. NG side and central DI of various designs and injection strategies were assessed experimentally along with CFD correlation. Significant effects on combustion metrics were quantified and explained via improved understanding of the in-cylinder flow effects due to NG injection. On-demand in-cylinder blending using E10 PFI and NG DI provides an additional lever to adjust in-cylinder turbulence as well as knock resistance across the engine speed and load range. NG DI improves part-load dilution tolerance due to higher in-cylinder turbulence and the high knock resistance of NG compared to E10 improves wide open throttle (WOT) performance while enabling increased compression ratios (CR). Vehicle level simulations suggest that implementing this strategy on a ½ ton pick-up truck with a naturally aspirated engine at 12.5:1 CR improves energy consumption on the aggressive US06 drive cycle by 15.5% compared to E10 operation, and gives a petroleum reduction of 78% over the blended range. There are challenges regarding market acceptance and widespread adoption of dual-fuel NG-gasoline vehicle applications beyond the performance degradation when the vehicle runs out of natural gas. Those challenges include practical concerns such as loss of cargo volume and payload due to the NG storage tank, extended NG refueling times, fueling convenience due to gasoline and NG fuel tanks, and limited NG fueling infrastructure.
Wallner, Thomas, Pamminger, Michael, Scarcelli, Riccardo, Powell, Christopher, Simeu, Severin Kamguia, Wooldridge, Steven, Boyer, Brad, Iqbal, Asim, Reese, Ron
The Review of Present and Future Energy Structure in China2019-01-06124/2/2019
Both the economy and energy demand increase rapidly in China. The government is facing severe problems from energy security, carbon emissions and environmental issues. The past trends and future plans of energy will have great influence on the transportation, construction and industry development. This paper summarizes the present and future energy structure in China. Conventional fossil energy, nuclear energy and renewable energy are all included. Electricity will account for more proportion in total energy consumption in the future, and the structure of electricity will be cleaner. That will promote the development of electric vehicles and the transformation of China’s automotive industry. The optimization of energy structure will accelerate the low-carbon development in China. China’s energy development will enter a new stage from the expansion of total quantity to the upgrading of quality and efficiency. In order to realize the Paris Climate Agreement, China must steadily control the total energy consumption. The energy consumption in China will be in a period of slow growth. Constantly optimizing the energy structure and promoting renewable energy will both ease the energy crisis and ensure that China’s goal of reducing CO2 emissions can be achieved. China will further strengthen international cooperation in energy projects in the future. Through the cooperation, the energy structure in China will be further optimized. The efficient technology research & development and infrastructure construction of energy storage and remote power transfer will be vital to energy development. It will have influence on the future promotion of various renewable energy resources. The government will propel the reform of the oil and gas industry, and gradually open the market to the social capital. This measure will emphasize the role of the market in the energy development.
Liu, Feiqi, Zhao, Fuquan, Hao, Han, Liu, Zongwei
Study of Flash Boiling Spray Combustion in a Spark Ignition Direct Injection Optical Engine Using Digital Image Processing Diagnostics2019-01-02524/2/2019
Flash boiling spray has been proven to be a useful method in providing finer fuel droplet and stronger evaporation in favor of creating a homogeneous fuel-air mixture. Combustion characteristics of flash boiling spray are thus valuable to be investigated systematically for aiding the development of efficient internal combustion system. An experimental study of flash boiling spray combustion in a SIDI optical engine under early injection has been conducted. The fuel, Iso-octane, was used across all tests. Three fuel spray conditions experimented in the study: normal liquid, transitional flash boiling and flare flash boiling sprays, within each case that Pa/Ps ratio was set in (>1), (0.3~1), and (<0.3) respectively. A small quartz insert on the piston enables optical access for observing combustion process; non-intrusive measurements on flame radicals has been carried out using a high-speed color camera. With the use of digital image processing and color analysis, the imaging system was turned into an abstract multi-spectral system to determine the characteristics of flame emission. In addition, the near infrared region was capable of being discriminated from the rest regions of the flame using HSV color model. The near infrared flame area and diffusion flame region as well as pool fire were found to be reduced, when implementing flash boiling spray under early injection condition. It is found that flash boiling spray contributes the reduction of particulate number (PN) emissions in exhaust gas and makes the improvement of indicated mean effective pressure (IMEP) and cyclic variation, which lead to more efficient combustion in SIDI engine under early injection.
Sun, Zhe, Ma, Zhen, Li, Xuesong, Xu, Min
Gasoline fuels growing number of commercial vehicles19TOFHP04_094/1/2019
Biodiesel may be the top alternative fuel for work truck fleets, according to the 2019 Fleet Purchasing Outlook Survey conducted by the National Truck Equipment Association (NTEA), but another “alt fuel” is gaining momentum in certain commercial vehicle (CV) segments: good old gasoline. Survey respondents listed biodiesel, at 16%, as their top alternative, followed by E85 and electric hybrid trucks, including plug-in hybrids. Extended range electric and propane/autogas both increased usage compared to 2018 results.
Gehm, Ryan
Energy, Exergy and Emission Performance Analysis of Air-Film Blade Cooled Turbo Prop Turbine for Heavy Duty Cargo Aircrafts2019-01-13893/19/2019
In the present scenario, when the non-conventional energy resources are still under development stage for their full potential as a source of energy for our fast growing population, gas turbines are one of the most promising power generation technologies. The gas turbine based power utilities are also gaining acceptance across globe, because of increase in extraction of natural gas. Further reduction in the price of natural gas would also result in the number of gas turbine units installed across globe and thus it is important to carry out the environmental analysis of gas turbine based utilities. The gas turbines are employed in power generation in industries, aircrafts and marine propulsion units. The present exercise carries out thermodynamic performance analysis i.e. energy, exergy and emission performance analysis of an air-craft gas turbine. The gas turbine blades of present cycle are assumed to be cooled by air-film blade cooling technique. The present paper carries out the thermodynamic analysis by varying cycle parameters i.e. cycle pressure ratio and turbine-rotor-inlet-temperature. The study further investigates the cycle based on second-law analysis which includes component-wise exergy destruction and rational efficiency, which shows the combustor to be the component with highest exergy destruction ~29%. The analysis further moves to predict emission performance analysis of air-craft gas turbine cycle and show that CO emission decreases with increase in compressor pressure ratio while NOX emission is found to be increase with increase in compressor pressure ratio. The results of the analysis have been represented in the form of useful graphs and performance maps which can be helpful to power utility developers.
Kumari, Anupam, Mishra, Shivam, Mohapatra, Alok Kumar, S, Sanjay
SAE Truck & Off-Highway Engineering: February 201919TOFHP022/1/2019
Over-the-air affair Remote updating of software and firmware on commercial trucks and off-highway machines is on the rise, not only for maintenance functions but also to add new features like operator-assist technology. Developments in engine-based gensets With demand for generator sets steady and regulatory change settling, suppliers can rationalize their offerings and push improvements in areas like noise abatement and economy. Testing, testing and even more testing The commercial-vehicle market is eager to adopt more ADAS and automated-driving innovations, but before those technologies get to the road they must first pass rigorous testing practices that prove their efficacy. Smart and connected powertrains FPT Tech Day reveals multi-power Cursor X concept, other "4.0 innovations" for hydrogen fuel cell, electric and natural gas propulsion. Editorial Medium-duty trucks make headway- and headlines Volvo CE, Skanska demonstrate concept electric site Argus responds over-the-air to combat new cyber threats SAE updates J3016 automated-driving graphic Tekscan goes fast-track with its high-speed tire scanning Emerson proposes electric-powered heat pumps for school buses Caterpillar Ventures invests in Fisker for electric future Deere displays ag equipment at CES to tout software, AI tech Q&A Tenneco talks 'clean air' tech, trends
CFD Simulation of Metal and Optical Configuration of a Heavy-Duty CI Engine Converted to SI Natural Gas. Part 2: In-Cylinder Flow and Emissions2019-01-00031/15/2019
Internal combustion diesel engines with optical access (a.k.a. optical engines) increase the fundamental understanding of combustion phenomena. However, optical access requirements result in most optical engines having a different in-cylinder geometry compared with the conventional diesel engine, such as a flat bowl-in-piston combustion chamber. This study investigated the effect of the bowl geometry on the flow motion and emissions inside a conventional heavy-duty direct-injection diesel engine that can operate in both metal and optical-access configurations. This engine was converted to natural-gas spark-ignition operation by replacing the fuel injector with a spark plug and adding a low-pressure gas injector in the intake manifold for fuel delivery, then operated at steady-state lean-burn conditions. A 3D CFD model based on the experimental data predicted that the different bowl geometry did not significantly affect in-cylinder emissions distribution. In addition, while in-cylinder flow motion was similar for both engine configurations, the different combustion chamber geometry affected the combustion-induced flow motion. Similar turbulence-generating mechanisms for engines with or without optical access show promise for optical investigations of cold-flow turbulence measurements representative of heavy-duty diesel engines converted to natural-gas spark-ignition operation.
Liu, Jinlong, Dumitrescu, Cosmin
Particle Emission Measurements in a SI CNG Engine Using Oils with Controlled Ash Content2019-01-00531/15/2019
Clean combustion is one of the inherent benefits of using a high methane content fuel, natural gas or biogas. A single carbon atom in the fuel molecule results, to a large extent, in particle-free combustion. This is due to the high energy required for binding multiple carbon atoms together during the combustion process, required to form soot particles. When scaling up this process and applying it in the internal combustion engine, the resulting emissions from the engine have not been observed to be as particle free as the theory on methane combustion indicates. These particles stem from the combustion of engine oil and its ash content. One common practice has been to lower the ash content to regulate the particulate emissions, as was done for diesel engines. For a gas engine, this approach has been difficult to apply, as the piston and valvetrain lubrication becomes insufficient. However, the low particle emissions from the combustion of CNG does allow for an investigation of particle contribution from engine oil ash content with only a minor particle contribution from the fuel itself. The hypothesis for this study is that there is a relationship between the engine oil ash content and the particulate emissions from a CNG engine. The investigation was conducted for several operating points with varying engine speeds and load on a single cylinder engine. The single cylinder approach was chosen to reduce sources of engine oil intrusion in the combustion chamber. The obtained results were not in line with the hypothesis, the particle emissions from the lower ash content oil did not decrease in number but the size of the particles did. The results also showed a spiking behavior in the particulate emissions, originating from the lubrication oil consumption past the piston rings. Mass flow through the engine proved to affect the particle size distribution as well as the total number of particles for all levels of oil ash content.
Adlercreutz, Ludvig, Cronhjort, Andreas, Stenlaas, Ola
Methane Direct Injection in an Optical SI Engine - Comparison between Different Combustion Modes2019-01-00831/15/2019
Natural gas, biogas, and biomethane are attractive fuels for compressed natural gas (CNG) engines because of their beneficial physical and chemical characteristics. This paper examines three combustion modes - homogeneous stoichiometric, homogeneous lean burn, and stratified combustion - in an optical single cylinder engine with a gas direct injection system operating with an injection pressure of 18 bar. The combustion process in each mode was characterized by indicated parameters, recording combustion images, and analysing combustion chemiluminescence emission spectra. Pure methane, which is the main component of CNG (up to 98%) or biomethane (> 98 %), was used as the fuel. Chemiluminescence emission spectrum analysis showed that OH* and CN* peaks appeared at their characteristic wavelengths in all three combustion modes. The peak of OH* and broadband CO2* intensities were strongly dependent on the air/fuel ratio conditions in the cylinder. Lower OH* and CO2* intensities were observed with lean air/fuel mixtures because under these conditions, more air was present, the combustion reactions were slower, and the cylinder pressure was higher. CN* was formed by the spark plasma and was detected over a particularly long period when using a dual coil ignition system. The intensities of the OH* and CN* signals correlated when using this ignition system. Combustion image analysis showed that the flame had a wrinkled boundary in stoichiometric and lean burn modes and was especially distorted in stratified mode. No yellow soot luminescence was observed during homogeneous combustion. However, the emission spectra and combustion images acquired during stratified combustion showed that soot formation occurred due to the presence of fuel-rich areas with inadequate mixing in the cylinder. The difficulty of maintaining stable fuel injection, achieving proper air/fuel mixing, and ensuring stable flame propagation in lean air/fuel mixtures increased cycle-to-cycle variations. However, the homogeneous lean burn and stratified combustion modes achieved significantly lower indicated specific fuel consumption values than stoichiometric combustion.
Melaika, Mindaugas, Andersson, Mats, Dahlander, Petter
CFD Simulation of Metal and Optical Configuration of a Heavy-Duty CI Engine Converted to SI Natural Gas. Part 1: Combustion Behavior2019-01-00021/15/2019
Internal combustion engines with optical access (a.k.a. optical engines) provide additional information in the quest for understanding the fundamental in-cylinder combustion phenomena. However, most optical engines have flat bowl-in-piston combustion chamber to optimize the visualization process, which is different, for example, from the traditional re-entrant bowl in compression ignition engines. A conventional heavy-duty direct-injection compression ignition engine was converted to spark ignition operation by replacing the fuel injector with a spark plug in both optical and metal setups to investigate the effect of the bowl geometry on flame propagation. Experimental data from steady-state lean-burn conditions was used to develop and validate a 3D CFD model of the engine. Numerical simulation results show that flame propagation in the radial direction was similar for both combustion chambers despite their different geometries. However, there were differences in the late combustion behavior. As a result, the similar flame propagation inside the optical engine suggests that such engines are best used to investigate flame inception and early flame propagation inside heavy-duty CI engines converted to natural gas spark ignition operation.
Liu, Jinlong, Dumitrescu, Cosmin
Regulation vs. Field Data: Managing Fuel Quality2019-26-01571/9/2019
Unlike in the aviation and marine sector, fuel specification in the on-road transportation sector are varied depending on the countries. Globally, the countries are going towards ultra-low sulfur fuels. In developed countries including in EU and the U.S., ultra-low sulfur fuels have been used since 2005-2006. In Asia, Japan lead the region with less than 10 ppm sulfur fuels introduced into the market in January 2005. More than a decade later, fuels with high sulfur content are still sold in most countries in Asia, Africa, the Middle East and Pacific. Facing pressure from environmentalists, these countries are focusing on sulfur reduction in their conventional fuels, along with improvement in their conventional fuels, along with improvement in their vehicle emission standards. On the other hand, in more advanced countries where they already have the cleanest possible conventional fuels, alternative fuels vehicles including electric vehicles are getting more attentions. Governments of developing countries are setting higher fuel quality standards to enable the implementation of more stringent vehicle emission standards. However, lack of fuel quality monitoring system in those countries results in the use of off-spec fuels. SGS worldwide market data delivers many examples. In the Philippines, 83% of premium plus gasoline samples have RON of 93 - 96.5 against the minimum requirement of 97 in the period of 2011-2017. Another example: 11.28 vol.% of methanol was found in a gasoline sample in 2016-2017 in the Philippines despite the specifications do not allow methanol to be present. One more example from Pakistan: the Manganese presence in all gasoline samples with concentration from 0.1 to 104 mg/kg in 2003-2017. Prolonged use of off-spec fuels will deteriorate exhaust emissions, damage the vehicles and worsen air quality. Therefore, a good understanding of fuel specifications and implementation of a good fuel quality monitoring system are needed to avoid severe productivity loss due to stalled vehicles on the road
Nurafiatin, Lucky
Development of Diesel-Ethanol Engine for HCV2019-26-00891/9/2019
Diesel engines dominate in Heavy-Duty applications due to its better fuel economy, higher durability and larger reliability. Fuels derived from petroleum resources are depleting daily and it’s become a scarce resource for future generation to come. With growing environmental consciousness of the adverse implications brought by excessive usage of fossil fuels, the battle for finding alternative fuels as their substitution is getting heated up. At present, renewable energy from bio-fuels has been peddled as one of the most promising substitution for petroleum derived diesel. Using bio-ethanol blended diesel fuel for automobile can significantly reduce diesel usage and exhaust greenhouse gases. Bio-ethanol can be produced by alcoholic fermentation of sucrose or simple sugars. The main drawback is that ethanol is immiscible with diesel fuel over a wide range of temperatures, and the hygroscopic nature of ethanol leading to phase separation in blend. In present study diesel-ethanol blends commonly known as E-diesel are prepared with different Ethanol proportion such as 5%, 7.7%, 10%, 12.5% and 15%. The effect of each blend is studied for engine performance & emissions. The method for diesel-ethanol blend preparation with different additives to improve the stability, lubricity and combustion efficiency is established. The scope of work includes to find the effect of ethanol blended diesel fuel on the existing, in-use vehicles complying to BS III & BS IV norms. The optimized E-diesel blend will be further tested for engine durability to find out the long term effect on the engine performance and its effects on FIE with such kind of new upcoming cross blended fuel.
Sutar, Prasanna Suresh, Bandyopadhyay, Debjyoti, Sonawane, Shailesh, Rairikar, S D, Kavathekar, Kishorkumar, Thipse, Sukrut, Marathe, Neelkanth
Blue-Light Imaging Sees Through FireTBMG-3340612/1/2018
A blue-light imaging method was developed that can be used to obtain visual data from large test fires where high temperatures could disable or destroy conventional electrical and mechanical sensors. The method provides detailed information to researchers using optical analysis such as digital image correlation (DIC), a technique that compares successive images of an object as it deforms under the influence of applied forces such as strain or heat. By precisely measuring the movement of individual pixels from one image to the next, scientists gain valuable insight about how the material responds over time, including behaviors such as strain, displacement, deformation, and even the microscopic beginnings of failure.
Wide-Area Chemical SensorTBMG-3339612/1/2018
The detection and localization of gas releases, such as methane from leaking natural gas pipelines or nitrogen oxides from failing electrical equipment, require high sensitivity to the target gas and insensitivity to non-target gases. Infrared (IR) absorption spectroscopy gives highly specific characterization of the identity and amount of airborne chemicals. Traditionally, spectroscopy techniques for long-range chemical sensing separate the “sensitive to x gas” and “insensitive to x gas” atmospheric measurements by quickly switching back and forth between them to reduce errors caused by any atmospheric changes. Because the samples are not measured at the same time, it is impossible to ensure that all atmospheric conditions (e.g., contaminants or humidity) remain constant between the two measurements.
Mazda details electrification strategy, confirms rotary engine's return18AUTP11_0611/1/2018
In an announcement from Japan in October, Mazda-one of the few established automakers to articulate a comprehensive longterm commitment to hybridization or all-electric vehicle propulsion-said it intends to incorporate some type of electrification in all its vehicles by 2030. Yet in nearly the same virtual breath, the company affirmed its connection to “soulful” forms of internal combustion, including a confirmation that it will renew its longstanding enthusiasm for the rotary engine. In a carefully-worded statement, Mazda reminded that many credible forecasts call for internal combustion to remain the dominant light-vehicle propulsion source for perhaps decades to come, while discretely laying out its plan for electrification-when and where it makes sense for the environment.
Visnic, Bill
Experimental Data of a Small-Size Gas ICE Driven Heat Pump (GHP) and Comparison of the Environmental Performance with an Electric Heat Pump2018-32-007010/30/2018
Worldwide, whenever thermal energy is required one of the most common supply solution is represented by the adoption of an electric heat pump. Nevertheless, other solutions may represent a valid option and the use of a Gas Heat Pump (GHP), based on an Internal Combustion Engine (ICE) fed by natural gas, is one of these. The experimental results of the operations of a GHP in a small-size enterprise in central Italy are presented: the test site, with its energy requests and technical constraints is described. Furtherly, a comparison with an electric heat pump is carried out by reproducing its behavior through a 1-D simulation tool developed in the Simulink environment. The advantages that the thermal generator based on the ICE can bring compared to an electric solution from the technical, economic, and environmental point of view are highlighted. In particular the latter aspect is analyzed considering the boundaries of different European Countries, whose energy mix for the electricity production determines different equivalent grid efficiencies. Finally, the main results are summarized in the conclusions, focusing the attention on the main advantages and most critical points which could affect the suitability of the installation of the ICE-based thermal generator instead of an electric heat pump.
Magnani, Sandro, Bellissima, Alessandro, Azuma, Hiroshi, Danti, Piero
Durability Improvement of Cylinder Head in Alternate Fuel Engines2018-32-005510/30/2018
Alternate fuels like LPG and CNG are beneficial in terms of operating cost and emissions as well. They also contribute to reduce CO2 emissions. These gas fuels are known for its problems in engines including wear of parts. Cylinder head valve - seat wear is higher in gas engines. This paper discusses the experimental work on reduction of valve -seat wear in 3 wheeler engine. In the development of new higher power version of the gas engine valve-seat interface wear is observed. Effect of this wear on performance, leak and emissions were studied, qualitative measurements of valve temperatures were studied at different conditions with different fuels. Combustion gas and part temperatures are higher in gas engines. Simulation test cycle is developed for the wear test and various solutions to reduce wear at the valve - seat interface were evaluated. Cost effective solution is implemented with minimum changes in engine.
Thiruvallur Loganathan, Balasubramanian, Elumalai, Duraikkannan, Kumaraswamy, Phaneesh, Lakshminarasimhan, V
Experimental Investigation of the Operations of a Small-Size ICE-Based CHP in an Italian Industrial Context2018-32-006310/30/2018
The distributed generation of electricity is worldwide growing thanks to the inherent advantages it brings to local users: in this context, micro-cogeneration systems allow cheap, affordable and reliable power and heating supply. The experimental operation of a 25 kWe Yanmar micro-CHP, based on a 4-stroke, 4-cylinder lean-burn internal combustion engine fed by natural gas exploiting the Miller cycle, during a time period of 1 year is here analyzed. The system is coupled with an absorption chiller and is installed in a small-size enterprise in central Italy, in order to supply the thermal base load of the company and part of the electric request. The main characteristics and the performance of the engine are widely analyzed, in particular the electric and thermal efficiencies are mapped through the whole year and the most remarkable differences due to the seasonal environmental conditions are underlined. A comparison is also carried out, in terms of environmental and economic performance, considering as benchmark the condition of the energy supply of the company before its installation, i.e. the power supply from the distribution grid and the thermal requests satisfied from an electric chiller and a natural gas boiler for the cooling and heating demand, respectively. Finally, a summary of the main results is presented, underlying the main advantages and the barriers that this technology is facing for its further spread.
Magnani, Sandro, Bellissima, Alessandro, Azuma, Hiroshi
Configuration Enables RFID Tags to Work as SensorsTBMG-3310010/1/2018
The detection and localization of gas releases, such as methane from leaking natural gas pipelines or nitrogen oxides from failing electrical equipment, require high sensitivity to the target gas and insensitivity to non-target gases. Infrared (IR) absorption spectroscopy gives highly specific characterization of the identity and amount of airborne chemicals. Traditionally, spectroscopy techniques for long-range chemical sensing separate the “sensitive to x gas” and “insensitive to x gas” atmospheric measurements by quickly switching back and forth between them to reduce errors caused by any atmospheric changes. Because the samples are not measured at the same time, it is impossible to ensure that all atmospheric conditions (e.g., contaminants or humidity) remain constant between the two measurements.
Study of Turbulent Entrainment Quasi-Dimensional Combustion Model for HCNG Engines with Variable Ignition Timings2018-01-16879/10/2018
Presently, urban transportation highly depends on the fossil fuels, but its rapid fluctuating economic issues and environmental consequences impose the variegation of energy sources. Hydrogen enriched compressed natural gas (HCNG) engines offer the potential of higher brake thermal efficiency with low emissions, which also satisfies the strict pollutant emission standards. The two-zone turbulent entrainment quasi-dimensional combustion model is developed to predict the combustion process of spark-ignited hydrogen enriched compressed natural gas-fueled engines. The fundamentals of thermodynamic process, turbulent flame propagation model and other sub-models like laminar burning velocity, adiabatic temperature and ignition lag model are introduced for the better accuracy. The experiments have been conducted for three different fuels; pure CNG, 20% HCNG, and 40% HCNG blends under MAP of 105 kPa for various excess air ratios (λ) and ignition timing (θi). The three calibration coefficient of the model; Turbulent intensity coefficient C2, the Taylor length scale coefficient C3, and Ignition lag coefficient Cig are tuned to generate the pressure traces which closely resembled to experimental results. After comparing the numerical simulation results with the experiment’s outcomes it is found that the predictive accuracy of the presented model is quite impressive, and it is well accepted for the extremely fuel lean conditions where issues of bad combustion become serious.
Mehra, Roopesh Kumar, Ma, Fanhua, Hao, Duan, Juknelevičius, Romualdas
The Use of Ozone in Low Temperature Methane Control for Natural Gas Applications2018-01-17029/10/2018
Lean operating natural gas heavy duty applications have advantages in terms of lower CO2 and PM compared to Diesel applications. This makes operating heavy duty applications on natural gas attractive and currently, they do not have to implement an exhaust particulate filter. However, the challenge is controlling methane emissions over a range of vehicle operating conditions. Methane is extremely stable and light off occurs at temperatures above 400 °C, with high efficiency occurring >500 °C and requires high precious metal loaded catalysts in the range of 150 - 200 g/ft3. Under stoichiometric conditions, 500 °C can be met in many engine operating points however, for lean operating applications, the exhaust temperature can be significantly lower than 500 °C posing a significant challenge for exhaust catalytic CH4 control. This paper will discuss synthetic gas reactor study results using ozone in the feed gas to perform low temperature methane control. A range of catalysts were characterised for the development of low temperature methane control and a non-precious metal catalyst was found to give high efficiency at low temperatures. The best catalyst screened did not contain PGM and was a current production catalyst that gave >60% CH4 control at 220 °C, in the presence of water. All other catalysts screened gave no significant methane control activity at low temperatures. The feed gas composition played a key role in the peak efficiency obtained. The data shows a significant improvement in ozone enhanced catalysis compared to more traditional precious metal based CH4 control routes.
Keenan, Matthew, Nicole, Jacques, Poojary, Damodara
Methodical Selection of Sustainable Fuels for High Performance Racing Engines2018-01-17499/10/2018
As the importance of sustainability increases and dominates the powertrain development within the automotive sector, this issue has to be addressed in motorsports as well. The development of sustainable high-performance fuels defined for the use in motorsports offers technical and environmental potential with the possibility to increase the sustainability of motorsports at the same or even a better performance level. At the moment race cars are predominantly powered by fossil fuels. However due to the emerging shift regarding the focus of the regulations towards high efficient powertrains during the last years the further development of the used fuels gained in importance. Moreover during the last decades a huge variety of sustainable fuels emerged that offer a range of different characteristics and that are produced based on waste materials or carbon dioxide. This study investigates the question of which sustainable fuels offer the characteristics suitable for high-performance race engines. Equivalents to gasoline, diesel and natural gas are examined separately in order to present the options with various engine concepts. The requirements for a high-performance fuel are defined based on experimental investigations emphasizing among other characteristics the importance of the knock resistance for gasoline-like fuels and the ignitability for diesel-like fuels. Furthermore the characteristics of the sustainable alternatives are analyzed. On the basis of the experimental results a comparison is carried out to match the fuel requirements with the characteristics and to select the optimal equivalent for fossil gasoline, diesel and natural gas. Moreover the sustainable fuels are evaluated with an environmental analysis including the fuel life cycle. The results show a potential to reduce the greenhouse gas emissions per mega joule energy content by up to 88%. This research assesses the broad variety of sustainable biologic and synthetic fuels concerning the potential use in motorsports and the resulting environmental benefits.
Schwarz, Lea, Bargende, Michael, Dreyer, Stefan, Baretzky, Ulrich, Kotauschek, Wolfgang, Wohlgemuth, Sebastian, Bach, Florian
POMDME as an Alternative Pilot Fuel for Dual-Fuel Engines: Optical Study in a RCEM and Application in an Automotive Size Dual-Fuel Diesel Engine2018-01-17349/10/2018
Dual-fuel natural gas engines are seen as an attractive solution for simultaneous reduction of pollutant and CO2 emissions while maintaining high engine thermal efficiency. However, engines of this type exhibit a tradeoff between misfire as well as high UHC emissions for small pilot injection amounts and higher emissions of soot and NOX for operation strategies with higher pilot fuel proportion. The aim of this study was to investigate POMDME as an alternative pilot fuel having the potential to mitigate the emissions tradeoff, enabling smokeless combustion due to high degree of oxygenation, and being less prone to misfire due to its higher cetane number. Furthermore, POMDME can be synthetized carbon neutrally. First, characteristics of POMDME ignition in methane/air mixture and the transition into premixed flame propagation were investigated optically in a rapid compression-expansion machine (RCEM) by employing Schlieren and OH* chemiluminescence imaging. A single-hole coaxial injector mounted at the cylinder periphery was used to admit POMDME or n-dodecane as the reference pilot fuel. In the second stage, POMDME was applied as a pilot-fuel in a VW 2 l 4-cylinder industrial Diesel engine modified for dual-fuel operation. Engine performance with POMDME and EN590 Diesel pilot-fuels was compared. In the RCEM, in air, dodecane and POMDME exhibit similar ignition delay times. In methane/air mixtures, ignition of both pilot fuels was deferred with increasing methane content, with stronger influence on POMDME than on dodecane. Indication of pilot-fuel over-mixing was observed for the shortest considered POMDME injections. In the engine experiment, while keeping the total combustion equivalence ratio constant, POMDME was found to have shorter ignition delays than Diesel fuel, attributed to its higher cetane number. At constant engine load using POMDME instead of Diesel pilot fuel, stable operation with lower pilot-fuel energy and mass input was possible along with soot mass reduction to close to zero.
Srna, Aleš, Barro, Christophe, Herrmann, Kai, Möri, Fabio, Hutter, Richard, Boulouchos, Konstantinos
Real Driving NO x Emissions from Euro VI Diesel Buses2018-01-18159/10/2018
Since 2013, Euro VI heavy-duty on-road vehicles have been on the market in the Europe. Regulated exhaust emissions, including nitrogen oxides and particulate matter, have been cut down to a very low level, independent of fuel (diesel or natural gas). Multiple research papers have shown that the regulated emissions from the Euro VI and US 2010 heavy-duty on-road vehicles tested on chassis dynamometers really deliver emission levels which correspond the type approval requirements, independent of the test cycle used. In-service conformity (ISC), which is included in the Euro VI legislation, requires heavy-duty on-road engine manufacturers to test and prove their engines to comply with the emission legislation during the engine in-use period. The measurements are carried out in the field using PEMS (Portable Emission Measurement System) equipment. This kind of testing, depicting real-world emissions is the final stage to confirm low real-life emissions. Although there is evidence that the exhaust aftertreatment systems of Euro VI heavy-duty on-road engines work well on an average, there is only a limited data of city buses covering their functionality over longer operation periods, especially not at lower ambient temperatures. Especially reduction of nitrogen oxides in the SCR-system (Selective Catalytic Reduction) is sensitive to SCR catalyst operation temperature, and also to impurities transferred from engine oil or fuel. This paper present results of a unique combination of chassis dynamometer measurements, on-road PEMS measurements and continuous NOx-emission monitoring during operation in winter condition from four Euro VI diesel city buses operating in the Helsinki metropolitan area. Based on the research done, four Euro VI city buses monitored and measured during the project showed decreased NOx conversion rate and increased tailpipe NOx emissions when operating in ambient temperatures below 0 °C. Especially in ambient temperatures below −10 °C, the continuous monitoring showed dramatically increased tailpipe NOx concentrations.
Söderena, Petri, Nylund, Nils-Olof, Pettinen, Rasmus, Mäkinen, Reijo
Modeling the Pilot Injection and the Ignition Process of a Dual Fuel Injector with Experimental Data from a Combustion Chamber Using Detailed Reaction Kinetics2018-01-17249/10/2018
The introduction of the so called Emission Controlled Areas within the IMO Tier III legislation forces manufacturers of maritime propulsion systems to adherence to stringent emission thresholds. Dual fuel combustion, which is characterized by the injection of a small amount of fuel oil to ignite a premixed natural gas air mixture, constitutes an option to meet this target. At high diesel substitution rates and very short pilot injection events, the injector is operated in the ballistic regime. This influences spray penetration, mixture formation and ignition behavior. In the present work, a seven-hole dual fuel injector was measured in a combustion chamber to provide data for the generation of a CFD model using the commercial code AVL FIRE®. The liquid and the vapor phase of the fuel spray were quantified by Mie-scattering and Schlieren-imaging technique for different chamber conditions. Based on the measured spray characteristics, a methodology was developed to imprint a velocity profile to the initial droplets in the CFD model, to depict the spray penetration for small injection durations. To characterize the ignition process and the flame propagation, measurements of the OH* emission and the natural luminosity of the flame were carried out. A detailed reaction mechanism, which is able to predict both diesel and dual fuel combustion, was integrated in the CFD model. The ignition delay was fitted to the experimental data by adapting the reaction mechanism for different chamber temperatures. The influence of the presence of natural gas on the ignition behavior was validated using data from a rapid compression machine. Even for low temperatures and high pressures, similar to the start of injection under engine operating conditions, a good correlation could be achieved. The developed knowledge will be transferred to an engine model to investigate the limits of dual fuel combustion processes.
Frühhaber, Jens, Peter, Andreas, Schuh, Sebastian, Lauer, Thomas, Wensing, Michael, Winter, Franz, Priesching, Peter, Pachler, Klaus
Effects of Hot and Cooled EGR for HC Reduction in a Dual-Fuel Premixed Charge Compression Ignition Engine2018-01-17309/10/2018
Most internal combustion engine makers have adopted after-treatment systems, such as selective catalytic reduction (SCR), diesel particulate filter (DPF), and diesel oxidation catalyst (DOC), to meet emission regulations. However, as the emission regulations become stricter, the size of the after-treatment systems become larger. This aggravates the price competitiveness of engine systems and causes fuel efficiency to deteriorate due to the increased exhaust pressure. Dual-fuel premixed charge compression ignition (DF-PCCI) combustion, which is one of the advanced combustion technologies, makes it possible to reduce nitrogen oxides (NOx) and particulate matter (PM) during the combustion process, while keeping the combustion phase controllability as a conventional diesel combustion (CDC). However, DF-PCCI combustion produces high amounts of hydrocarbon (HC) and carbon monoxide (CO) emissions due to the bulk quenching phenomenon under low load conditions as a huddle of commercialization. In this study, the effects of exhaust gas recirculation (EGR) rate and EGR temperature were investigated to overcome the bulk quenching phenomenon under low load conditions in the DF-PCCI combustion. Natural gas (NG) and diesel were selected for low reactivity fuel (LRF) and high reactivity fuel (HRF) respectively. As experimental results, adopting the high temperature EGR could reduce the HC emission, and improve combustion efficiency (ηc) and fuel conversion efficiency (ηf), while maintaining the NOx and PM emissions under the EU-VI emission regulations. The results suggest that controlling the global equivalence ratio (∅global) and increasing the initial charge temperature by hot-EGR are quite effective way to mitigate the bulk quenching phenomenon and incomplete combustion under low load conditions in the DF-PCCI combustion.
Shim, Eui joon, Park, Hyunwook, Bae, Choongsik
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