scholarly journals Numerical Analysis of High-Pressure Direct Injection Dual-Fuel Diesel-Liquefied Natural Gas (LNG) Engines

Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 261 ◽  
Author(s):  
Alberto Boretti
Keyword(s):  
High Pressure ◽  
Steady State ◽  
Liquid Phase ◽  
Natural Gas ◽  
Power Density ◽  
Conversion Efficiency ◽  
Liquefied Natural Gas ◽  
Dual Fuel ◽  
Fuel Conversion ◽  
Better Than

Dual fuel engines using diesel and fuels that are gaseous at normal conditions are receiving increasing attention. They permit to achieve the same (or better) than diesel power density and efficiency, steady-state, and substantially similar transient performances. They also permit to deliver better than diesel engine-out emissions for CO2, as well as particulate matter, unburned hydrocarbons, and nitrous oxides. The adoption of injection in the liquid phase permits to further improve the power density as well as the fuel conversion efficiency. Here, a model is developed to study a high-pressure, 1600 bar, liquid phase injector for liquefied natural gas (LNG) in a high compression ratio, high boost engine. The engine features two direct injectors per cylinder, one for the diesel and one for the LNG. The engine also uses mechanically assisted turbocharging (super-turbocharging) to improve the steady-state and transient performances of the engine, decoupling the power supply at the turbine from the power demand at the compressor. Results of steady-state simulations show the ability of the engine to deliver top fuel conversion efficiency, above 48%, and high efficiencies, above 40% over the most part of the engine load and speed range. The novelty of this work is the opportunity to use very high pressure (1600 bar) LNG injection in a dual fuel diesel-LNG engine. It is shown that this high pressure permits to increase the flow rate per unit area; thus, permitting smaller and lighter injectors, of faster actuation, for enhanced injector-shaping capabilities. Without fully exploring the many opportunities to shape the heat release rate curve, simulations suggest two-point improvements in fuel conversion efficiency by increasing the injection pressure.

scholarly journals Effect of hydrogen addition in diesel/natural gas dual-fuel combustion with late injection

2021 ◽  
Vol 312 ◽  
pp. 08005
Author(s):  
Antonio Caricato ◽  
Antonio Paolo Carlucci ◽  
Antonio Ficarella ◽  
Luciano Strafella
Keyword(s):  
Natural Gas ◽  
Conversion Efficiency ◽  
Early Stage ◽  
Combustion Process ◽  
Pollutant Emission ◽  
Dual Fuel ◽  
Injection Timing ◽  
Pilot Injection ◽  
Fuel Conversion ◽  
Hydrogen Addition

In a previous work, the effectiveness of late pilot injection on improving combustion behaviour – in terms of fuel conversion efficiency and pollutant emission levels – in a diesel/natural gas dual-fuel engine was assessed. Then, an additional set of experiments was performed, aiming at speeding up the combustion process possibly without penalizing NOx levels. Therefore, hydrogen was added to natural gas in a percentage equal to 10%. Results show that hydrogen addition has a significant effect on the combustion development specially during the early stage of combustion: ignition delay is shortened and combustion centre is advanced, while the combustion duration increases when pilot injection timing is set to conventional values, while remains basically unchanged for late timings. Fuel conversion efficiency is only slightly penalized when hydrogen is added. Moreover, it was confirmed that, in general, combustion strategy with late pilot injection timing does not penalize fuel conversion efficiency; indeed, in some cases, it actually increases. Concerning regulated emission levels, it is again proven that late pilot injection does not penalize pollutant production: the hydrocarbons and carbon monoxide reduce as pilot injection is delayed, probably due to the higher temperatures reached into the cylinder during most part of the expansion stroke. Moreover, adding hydrogen always reduces their levels. Concerning NOx, they are drastically reduced delaying pilot injection; as expected, hydrogen addition promotes NOx formation, but the increase, evident with conventional pilot injection timings, becomes marginal with late injection strategy. Therefore, combustion strategy performance with late pilot injection in dual-fuel diesel/natural gas combustion conditions can be further improved with 10% hydrogen addition to natural gas.

Performance and emissions of an electronic control common-rail diesel engine fuelled with liquefied natural gas-diesel dual-fuel under an optimization control scheme

2018 ◽  
Vol 233 (6) ◽  
pp. 1380-1390 ◽  
Author(s):  
Jiantong Song ◽  
Chunhua Zhang ◽  
Guoqing Lin ◽  
Quanchang Zhang
Keyword(s):  
Diesel Engine ◽  
Natural Gas ◽  
Fuel Consumption ◽  
Liquefied Natural Gas ◽  
Common Rail ◽  
Dual Fuel ◽  
Brake Specific Fuel Consumption ◽  
Electronic Control ◽  
Control Scheme ◽  
Optimization Control

In order to reduce the fuel consumption and hydrocarbon and CO emissions of liquefied natural gas-diesel dual-fuel engines under light loads, an optimization control scheme, in which the dual-fuel engine runs in original diesel mode under light loads, is used in this paper. The performance and exhaust emissions of the dual-fuel engine and the original diesel engine are compared and analyzed by bench tests of an electronic control common-rail diesel engine. Experimental results show that the brake-specific fuel consumption and hydrocarbon and CO emissions of the liquefied natural gas-diesel dual-fuel engine are not deteriorated under light loads. Compared with diesel, the brake power and torque of dual-fuel remain unchanged, the brake-specific fuel consumption decreases, and the smoke density and CO2 emissions of dual-fuel decrease, while the hydrocarbon and CO emissions increase, and there is no significant difference in NOx emissions.

A Machine Learning Modeling Approach for High Pressure Direct Injection Dual Fuel Compressed Natural Gas Engines

2020 ◽  
Author(s):  
Michael Karpinski-Leydier ◽  
Ryozo Nagamune ◽  
Patrick Kirchen
Keyword(s):  
Machine Learning ◽  
High Pressure ◽  
Natural Gas ◽  
Direct Injection ◽  
Dual Fuel ◽  
Compressed Natural Gas ◽  
Natural Gas Engines ◽  
Modeling Approach

Investigation of the High-Pressure-Dual-Fuel (HPDF) combustion process of natural gas on a fully optically accessible research engine

2019 ◽  
Author(s):  
Stephan Gleis ◽  
Stephanie Frankl ◽  
Dominik Waligorski ◽  
Dr.-Ing. Maximilian Prager ◽  
Prof. Dr.-Ing. Georg Wachtmeister
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Combustion Process ◽  
Dual Fuel

IDENTIFIKASI DAN ANALISIS MATERIAL CASING REGULATOR GAS

2021 ◽  
Vol 26 (2) ◽  
pp. 111-121
Author(s):  
Freddy Marpaung ◽  
Nyoman Artana
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Liquefied Natural Gas

Regulator gas merupakan salah satu komponen penting pada system tanki liquefied natural gas (LNG). Komponen ini didesain harus mampu bekerja pada temperature rendah ekstrim dan tekanan tinggi. Dalam keseluruhan proses desain, material memiliki peran penting sehingga designer harus dapat mengidentifikasi jenis material dengan fungsionalitas spesifik agar ditemukan konsep desain yang layak. Identifikasi material tersebut dapat digunakan sebagai informasi awal mengenai sifat mekanik dan struktur mikro dari material. Tujuan dari penelitian ini adalah menyajikan data identifikasi material casing regulator gas alam jenis Belgas P39 dan memberikan rekomendasi persyaratan material yang harus dipenuhi oleh perusahaan lokal yang tertarik untuk mengembangkan material casing regulator tersebut. Pada paper ini, identifikasi material casing regulator Belgas P39 high pressure dilakukan melalui serangkaian pengujian, diantaranya pengujian komposisi kimia, pengujian kekerasan, pengujian metalografi, dan pengujian SEM-EDS. Selanjutnya data hasil pengujian tersebut dibandingkan dengan data pembanding standar. Hasil penelitian menunjukkan bahwa material casing regulator Belgas P39 high pressure termasuk dalam paduan kuningan jenis duplex.

Improving the Efficiency of the Advanced Injection Low Pilot Ignited Natural Gas Engine Using Organic Rankine Cycles

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
K. K. Srinivasan ◽  
P. J. Mago ◽  
G. J. Zdaniuk ◽  
L. M. Chamra ◽  
K. C Midkiff
Keyword(s):  
Natural Gas ◽  
Conversion Efficiency ◽  
Waste Heat ◽  
Injection Timing ◽  
Base Line ◽  
Nox Emissions ◽  
Oxides Of Nitrogen ◽  
Fuel Conversion ◽  
Lean Combustion ◽  
Organic Rankine Cycles

Intense energy security debates amidst the ever increasing demand for energy in the US have provided sufficient impetus to investigate alternative and sustainable energy sources to the current fossil fuel economy. This paper presents the advanced (injection) low pilot ignition natural gas (ALPING) engine as a viable, efficient, and low emission alternative to conventional diesel engines, and discusses further efficiency improvements to the base ALPING engine using organic rankine cycles (ORC) as bottoming cycles. The ALPING engine uses advance injection (50–60deg BTDC) of very small diesel pilots in the compression stroke to compression ignite a premixed natural gas-air mixture. It is believed that the advanced injection of the higher cetane diesel fuel leads to longer in-cylinder residence times for the diesel droplets, thereby resulting in distributed ignition at multiple spatial locations, followed by lean combustion of the higher octane natural gas fuel via localized flame propagation. The multiple ignition centers result in faster combustion rates and higher fuel conversion efficiencies. The lean combustion of natural gas leads to reduction in local temperatures that result in reduced oxides of nitrogen (NOx) emissions, since NOx emissions scale with local temperatures. In addition, the lean premixed combustion of natural gas is expected to produce very little particulate matter emissions (not measured). Representative base line ALPING (60deg BTDC pilot injection timing) (without the ORC) half load (1700rpm, 21kW) operation efficiencies reported in this study are about 35% while the corresponding NOx emission is about 0.02g∕kWh, which is much lower than EPA 2007 Tier 4 Bin 5 heavy-duty diesel engine statutes of 0.2g∕kWh. Furthermore, the possibility of improving fuel conversion efficiency at half load operation with ORCs using “dry fluids” is discussed. Dry organic fluids, due to their lower critical points, make excellent choices for waste heat recovery Rankine cycles. Moreover, previous studies indicate that dry fluids are more preferable compared to wet fluids because the need to superheat the fluid to extract work from the turbine is eliminated. The calculations show that ORC—turbocompounding results in fuel conversion efficiency improvements of the order of 10% while maintaining the essential low NOx characteristics of ALPING combustion.

scholarly journals A Review on Liquefied Natural Gas as Fuels for Dual Fuel Engines: Opportunities, Challenges and Responses

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6127
Author(s):  
Md Arman Arefin ◽  
Md Nurun Nabi ◽  
Md Washim Akram ◽  
Mohammad Towhidul Islam ◽  
Md Wahid Chowdhury
Keyword(s):  
Natural Gas ◽  
Internal Combustion Engines ◽  
Ghg Emissions ◽  
Liquefied Natural Gas ◽  
Future Research ◽  
Dual Fuel ◽  
Combustion Engines ◽  
Emission Regulations ◽  
Dual Fuel Engines ◽  
Sustainable Fuels

Climate change and severe emission regulations in many countries demand fuel and engine researchers to explore sustainable fuels for internal combustion engines. Natural gas could be a source of sustainable fuels, which can be produced from renewable sources. This article presents a complete overview of the liquefied natural gas (LNG) as a potential fuel for diesel engines. An interesting finding from this review is that engine modification and proper utilization of LNG significantly improve system efficiency and reduce greenhouse gas (GHG) emissions, which is extremely helpful to sustainable development. Moreover, some major recent researches are also analyzed to find out drawbacks, advancement and future research potential of the technology. One of the major challenges of LNG is its higher flammability that causes different fatal hazards and when using in dual-fuel engine causes knock. Though researchers have been successful to find out some ways to overcome some challenges, further research is necessary to reduce the hazards and make the fuel more effective and environment-friendly when using as a fuel for a diesel engine.

Liquefied Natural Gas (LNG) as a Freight Railroad Fuel: Perspective From a Western U.S. Railroad

2012 ◽  
Author(s):  
Michael E. Iden
Keyword(s):  
Natural Gas ◽  
Large Scale ◽  
Liquefied Natural Gas ◽  
Rolling Stock ◽  
Dual Fuel ◽  
Technology System ◽  
Pilot Fuel ◽  
Gas Ignition ◽  
Gas Fuel ◽  
Lng Fuel

The use of liquefied natural gas (LNG) as a line-haul locomotive fuel is not a new idea, despite recent publicity, with previous work stretching back into the 1980s. Intense publicity has been given to recent announcements about developing dual-fuel locomotive engines which can burn natural gas as the primary fuel, using diesel fuel only as a pilot fuel for gas ignition. However, developing a locomotive engine capable of using gaseous fuel may prove to be only one of five major challenges to widespread adoption of LNG as a freight railroad fuel: 1. Dual-fuel line-haul locomotives with engines which can use natural gas fuel must be developed and made available for use. 2. Natural gas fuel must be made available to dual-fuel locomotives, either onboard the locomotive itself or by using LNG tenders coupled to the locomotives. 3. LNG must be stored and available for refueling dual-fuel locomotives or their tenders at logical locations along railroad corridors where such locomotives are to be used. 4. Natural gas (from gas fields or pipelines) must be available along with liquefaction plants to convert the gas into cryogenic LNG fuel. 5. The safe operation of trains and locomotives, and safe maintenance of rolling stock, is paramount and cannot be compromised (nor should the efficiency of the rail system) should dual-fuel locomotives and LNG tenders supplant or replace conventional diesel-fueled locomotives. For LNG to become an effective large-scale freight railroad fuel, all five factors must be managed jointly and treated as a 5-legged technology system. If any one of the five “technology legs” is weak or improperly developed, the entire LNG-based system may be unsuitable in the freight railroad environment.

scholarly journals Development and Integration of the Dual Fuel Combustion System for the MGT Gas Turbine Family

2021 ◽  
Author(s):  
Bernhard Ćosić ◽  
Frank Reiß ◽  
Marc Blümer ◽  
Christian Frekers ◽  
Franklin Genin ◽  
...  
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Gas Turbine ◽  
Distribution System ◽  
Gas Turbines ◽  
Liquid Fuel ◽  
Flame Stabilization ◽  
Experimental Investigations ◽  
Dual Fuel ◽  
Combustion System

Abstract Industrial gas turbines like the MGT6000 are often operated as power supply or as mechanical drives for pumps and compressors at remote locations on islands and in deserts. Moreover, small gas turbines are used in CHP applications with a high need for availability. In these applications, liquid fuels like ‘Diesel Fuel No. 2’ can be used either as main fuel or as backup fuel if natural gas is not reliably available. The MAN Gas Turbines (MGT) operate with the Advanced Can Combustion (ACC) system, which is already capable of ultra-low NOx emissions for a variety of gaseous fuels. This system has been further developed to provide dry dual fuel capability to the MGT family. In the present paper, we describe the design and detailed experimental validation process of the liquid fuel injection, and its integration into the gas turbine package. A central lance with an integrated two-stage nozzle is employed as a liquid pilot stage, enabling ignition and start-up of the engine on liquid fuel only, without the need for any additional atomizing air. The pilot stage is continuously operated to support further the flame stabilization across the load range, whereas the bulk of the liquid fuel is injected through the premixed combustor stage. The premixed stage comprises a set of four decentralized nozzles placed at the exit of the main air swirler. These premixed nozzles are based on fluidic oscillator atomizers, wherein a rapid and effective atomization of the liquid fuel is achieved through self-induced oscillations of the liquid fuel stream. We present results of numerical and experimental investigations performed in the course of the development process illustrating the spray, hydrodynamic, and thermal performance of the pilot injectors. Extensive testing of the burner at atmospheric and full load high-pressure conditions has been performed, before verification of the whole combustion system within full engine tests. The burner shows excellent emission performance (NOx, CO, UHC, soot) without additional water injection, while maintaining the overall natural gas performance. Soot and particle emissions, quantified via several methods, are well below legal restrictions. Furthermore, when not in liquid fuel operation, a continuous purge of the injectors based on compressor outlet (p2) air has been laid out. Generic atmospheric coking tests were conducted before verifying the purge system in full engine tests. Thereby we completely avoid the need for an additional high-pressure auxiliary compressor or demineralized water. We show the design of the fuel supply and distribution system. We designed it to allow for rapid fuel switchovers from gaseous fuel to liquid fuel, and for sharp load jumps. Finally, we discuss the integration of the dual fuel system into the standard gas turbine package of the MGT6000 in detail.

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