Improvement of Fuel Injection Process in Dual-Fuel Marine Engine

This paper presents research on the combustion and emission characteristics of a four-stroke Natural gas–Diesel dual-fuel marine engine at full load. The AVL FIRE R2018a (AVL List GmbH, Graz, Austria) simulation software was used to conduct three-dimensional simulations of the combustion process and emission formations inside the engine cylinder in both diesel and dual-fuel mode to analyze the in-cylinder pressure, temperature, and emission characteristics. The simulation results were then compared and showed a good agreement with the measured values reported in the engine’s shop test technical data. The simulation results showed reductions in the in-cylinder pressure and temperature peaks by 1.7% and 6.75%, while NO, soot, CO, and CO2 emissions were reduced up to 96%, 96%, 86%, and 15.9%, respectively, in the dual-fuel mode in comparison with the diesel mode. The results also show better and more uniform combustion at the late stage of the combustions inside the cylinder when operating the engine in the dual-fuel mode. Analyzing the emission characteristics and the engine performance when the injection timing varies shows that, operating the engine in the dual-fuel mode with an injection timing of 12 crank angle degrees before the top dead center is the best solution to reduce emissions while keeping the optimal engine power.

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A phenomenological combustion analysis of a dual-fuel natural-gas diesel engine

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1177/0954407016633337 ◽

2016 ◽

Vol 231 (1) ◽

pp. 66-83 ◽

Cited By ~ 13

Author(s):

Shuonan Xu ◽

David Anderson ◽

Mark Hoffman ◽

Robert Prucka ◽

Zoran Filipi

Keyword(s):

Diesel Engine ◽

Natural Gas ◽

Heat Release ◽

Diesel Fuel ◽

Fuel Injection ◽

Dual Fuel ◽

Injection Timing ◽

Heavy Duty ◽

Engine System ◽

Wiebe Function

Energy security concerns and an abundant supply of natural gas in the USA provide the impetus for engine designers to consider alternative gaseous fuels in the existing engines. The dual-fuel natural-gas diesel engine concept is attractive because of the minimal design changes, the ability to preserve a high compression ratio of the baseline diesel, and the lack of range anxiety. However, the increased complexity of a dual-fuel engine poses challenges, including the knock limit at a high load, the combustion instability at a low load, and the transient response of an engine with directly injected diesel fuel and port fuel injection of compressed natural gas upstream of the intake manifold. Predictive simulations of the complete engine system are an invaluable tool for investigations of these conditions and development of dual-fuel control strategies. This paper presents the development of a phenomenological combustion model of a heavy-duty dual-fuel engine, aided by insights from experimental data. Heat release analysis is carried out first, using the cylinder pressure data acquired with both diesel-only and dual-fuel (diesel and natural gas) combustion over a wide operating range. A diesel injection timing correlation based on the injector solenoid valve pulse widths is developed, enabling the diesel fuel start of injection to be detected without extra sensors on the fuel injection cam. The experimental heat release trends are obtained with a hybrid triple-Wiebe function for both diesel-only operation and dual-fuel operation. The ignition delay period of dual-fuel operation is examined and estimated with a predictive correlation using the concept of a pseudo-diesel equivalence ratio. A four-stage combustion mechanism is discussed, and it is shown that a triple-Wiebe function has the ability to represent all stages of dual-fuel combustion. This creates a critical building block for modeling a heavy-duty dual-fuel turbocharged engine system.

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Influence of deforming of common rail diesel injectors parts on the fuel injection process

10.36652/1684-1298-2021-4-7-12 ◽

2021 ◽

pp. 4-12

Author(s):

Keyword(s):

High Pressures ◽

Fuel Injection ◽

Experimental Studies ◽

Common Rail ◽

Electronic Control ◽

Fuel System ◽

Fuel Supply ◽

Injection Process ◽

Injection Cycle

Experimental studies have revealed a significant impact of deformation of Сommon Rail injector parts on the fuel supply process. High pressures alter the structure of the fuel supply cy-cle. Theforward front of the fuel supply cycle begins with the stage of unloading the deformed parts of the injector. The rear front of the fuel supply cycle ends with the stage of deformation of the injector parts. The calculated and experimental determination of cyclic fuel supply gave similar results. The developed method of determining the duration of the injection cycle stages creates a basis for experimental verification of mathematical models. Keywords: injector, Common Rail, diesel, fuel system, electronic control, needle, fuel injection

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

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4052504 ◽

2021 ◽

Author(s):

Bernhard Ćosić ◽

Frank Reiss ◽

Marc Blümer ◽

Christian Frekers ◽

Franklin Genin ◽

...

Keyword(s):

Gas Turbine ◽

Distribution System ◽

Gas Turbines ◽

Liquid Fuel ◽

Fuel Injection ◽

Liquid Fuels ◽

Dual Fuel ◽

Gaseous Fuels ◽

Supply And Distribution ◽

Industrial Gas Turbines

Abstract Industrial gas turbines like the MGT6000 are often operated as power supply or as mechanical drives. 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 capable of ultra-low NOx emissions for gaseous fuels. This system has been further developed to provide dry dual fuel capability. 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. The pilot stage is continuously operated, whereas the bulk of the liquid fuel is injected through the premixed combustor stage. The premixed stage comprises a set of four decentralized nozzles based on fluidic oscillator atomizers, wherein atomization of the liquid fuel is achieved through self-induced oscillations. We present results illustrating the spray, hydrodynamic, and emission performance of the injectors. Extensive testing of the burner at atmospheric and full load high-pressure conditions has been performed, before verification within full engine tests. We show the design of the fuel supply and distribution system. Finally, we discuss the integration of the dual fuel system into the standard gas turbine package of the MGT6000.

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