Parametric Analysis of the Combustion Cycle of a Diesel Engine for Operation on Natural Gas

The publication research task is related to one of the solution aspects in reference to decarbonization of transport by transferring the operation of diesel engines to natural gas. The results of converted diesel engines into operation with dual-fuel (D-NG) without significant constructive modifications are focused on forecasting the energy efficiency parameters of in-service engine models and evaluation of the reserves improvement. This paper presents energy efficiency parameters and characteristics of the combustion cycle methodological optimization of high-speed 79.5/95.5 mm diesel engine with a conventional fuel injection system. Interrelations between the indicated efficiency (ηi), combustion cycle performance parameters (excess air ratio (α), compression ratio (ε), degree of pressure increase in the cylinder (λ), maximum cycle pressure (pmax), air pressure (pk), air temperature (Tk) after compression, etc.), and heat release characteristics were determined and researched. Directions of the optimization when the engines were operating in a wide range of load (pmi) modes were also obtained: the low energy efficiency in the low-load mode were due to reduced heat release dynamics (combustion time increased up to 200° CA). The main influencing factors for ηi were the pilot-injection portion phase (φinj) and α, optimization of ε was inefficient. To avoid exceeding the permissible limits of reliability for pmax, the realized reserve of ηi increase was estimated as 10%. Methodological tools for the practical application of parametric analysis to the conversion of diesel to dual-fuel operation have been developed and adapted in the form of a numerical modeling algorithm, which was presented in nomogram form. For improvement of initial energy parameters for a specific engine models heat release characteristics identification, accurate methods must be used. The proposed methodology is seen as a theoretical tool for a dual-fuel conversion models for in-service engines and has benefit of a practical use of a fast application in the industrial field.

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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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Research on Fuel Efficiency and Emissions of Converted Diesel Engine with Conventional Fuel Injection System for Operation on Natural Gas

Energies ◽

10.3390/en12122413 ◽

2019 ◽

Vol 12 (12) ◽

pp. 2413 ◽

Cited By ~ 2

Author(s):

Lebedevas ◽

Pukalskas ◽

Daukšys ◽

Rimkus ◽

Melaika ◽

...

Keyword(s):

Energy Efficiency ◽

Natural Gas ◽

Fuel Injection ◽

Injection System ◽

Dual Fuel ◽

Injection Timing ◽

Fuel Injection System ◽

Significant Deterioration ◽

Engine Operation ◽

Conventional Fuel

This paper presents a study on the energy efficiency and emissions of a converted high-revolution bore 79.5 mm/stroke 95 mm engine with a conventional fuel injection system for operation with dual fuel feed: diesel (D) and natural gas (NG). The part of NG energy increase in the dual fuel is related to a significant deterioration in energy efficiency (ηi), particularly when engine operation is in low load modes and was determined to be below 40% of maximum continuous rating. The effectiveness of the D injection timing optimisation was established in high engine load modes within the range of a co-combustion ratio of NG ≤ 0.4: with an increase in ηi, compared to D, the emissions of NOx+ HC decreased by 15% to 25%, while those of CO2 decreased by 8% to 16%; the six-fold CO emission increase, up to 6 g/kWh, was unregulated. By referencing the indicated process characteristics of the established NG phase elongation in the expansion stroke, the combustion time increase as well as the associated decrease in the cylinder excess air ratio (α) are possible reasons for the increase in the incomplete combustion product emission.

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Performance and exhaust emission characteristics of dual-fuel diesel engine with a natural gas direct injection system Takahisa Koseki, Yasuhiro Daisho, Akihiro Ikeda, Ryoji Kihara, Takeshi saito (Waseda University)

JSAE Review ◽

10.1016/s0389-4304(97)85181-8 ◽

1997 ◽

Vol 18 (2) ◽

pp. 209

Keyword(s):

Diesel Engine ◽

Natural Gas ◽

Direct Injection ◽

Injection System ◽

Exhaust Emission ◽

Dual Fuel ◽

Emission Characteristics

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A Phenomenological Model for Combustion and Emissions in Small Bore, High Speed, Direct Injection Diesel Engines

ASME 2005 Internal Combustion Engine Division Spring Technical Conference ◽

10.1115/ices2005-1024 ◽

2005 ◽

Author(s):

N. A. Henein ◽

I. P. Singh ◽

L. Zhong ◽

Y. Poonawala ◽

J. Singh ◽

...

Keyword(s):

Diesel Engine ◽

Diesel Engines ◽

Phenomenological Model ◽

High Speed ◽

Gas Flow ◽

Fuel Injection ◽

Direct Injection ◽

Injection System ◽

Injection Process ◽

Wide Range

This paper introduces a phenomenological model for the fuel distribution, combustion, and emissions formation in the small bore, high speed direct injection diesel engine. A differentiation is made between the conditions in large bore and small bore diesel engines, particularly regarding the fuel impingement on the walls and the swirl and squish gas flow components. The model considers the fuel injected prior to the development of the flame, fuel injected in the flame, fuel deposited on the walls and the last part of the fuel delivered at the end of the injection process. The model is based on experimental results obtained in a single-cylinder, 4-valve, direct-injection, four-stroke-cycle, water-cooled, diesel engine equipped with a common rail fuel injection system. The engine is supercharged with heated shop air, and the exhaust back pressure is adjusted to simulate actual turbo-charged diesel engine conditions. The experiments covered a wide range of injection pressures, EGR rates, injection timings and swirl ratios. Correlations and 2-D maps are developed to show the effect of combinations of the above parameters on engine out emissions. Emphasis is made on the nitric oxide and soot measured in Bosch Smoke Units (BSU).

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Comparison of Propane and Methane Performance and Emissions in a Turbocharged Direct Injection Dual Fuel Engine

ASME 2010 Internal Combustion Engine Division Fall Technical Conference ◽

10.1115/icef2010-35128 ◽

2010 ◽

Author(s):

C. M. Gibson ◽

A. C. Polk ◽

N. T. Shoemaker ◽

K. K. Srinivasan ◽

S. R. Krishnan

Keyword(s):

Diesel Engine ◽

Natural Gas ◽

Direct Injection ◽

Experimental Results ◽

Ignition Source ◽

Dual Fuel ◽

Wide Range ◽

Performance And Emissions ◽

Di Diesel Engine ◽

Dual Fueling

With increasingly restrictive NOx and PM emissions standards, the recent discovery of new natural gas reserves, and the possibility of producing propane efficiently from biomass sources, dual fueling strategies have become more attractive. This paper presents experimental results from dual-fueling a four-cylinder turbocharged DI diesel engine with propane or methane (a natural gas surrogate) as the primary fuel and diesel as the ignition source. Experiments were performed with the stock ECU at a constant speed of 1800 rev/min, and a wide range of BMEPs (2.7 to 11.6 bar) and percent energy substitutions (PES) of C3H8 and CH4. Brake thermal efficiencies (BTE) and emissions (NOx, smoke, THC, CO, and CO2) were measured. Maximum PES levels of about 80–95 percent with CH4 and 40–92 percent with C3H8 were achieved. Maximum PES was limited by poor combustion efficiencies and engine misfire at low loads for both C3H8 and CH4, and the onset of knock above 9 bar BMEP for C3H8. While dual fueling BTEs were lower than straight diesel BTEs at low loads, they approached diesel BTE values at high loads. With dual fueling, NOx and smoke reductions (from diesel values) were as high as 66–68 percent and 97 percent, respectively, but CO and THC emissions were significantly higher with increasing PES at all engine loads.

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INVESTIGATION ON THE AIR-GAS CHARACTERISTICS OF AIR-HYDROGEN MIXER DESIGNED FOR DUAL FUEL – ENGINES

EUREKA Physics and Engineering ◽

10.21303/2461-4262.2021.001722 ◽

2021 ◽

pp. 66-77

Author(s):

Alaulddin A. Kazum ◽

Osam H. Attia ◽

Ali I. Mosa ◽

Nor Mariah. Adam

Keyword(s):

Diesel Engine ◽

Diesel Engines ◽

Alternative Fuels ◽

Dual Fuel ◽

Engine Operation ◽

Friction Forces ◽

Fuel Ratio ◽

Head Surface ◽

Wide Range ◽

Reduce Emissions

High smoke emissions, nitrogen oxide and particulate matter typically produced by diesel engines. Diminishing the exhausted emissions without doing any significant changes in their mechanical configuration is a challenging subject. Thus, adding hydrogen to the traditional fuel would be the best practical choice to ameliorate diesel engines performance and reduce emissions. The air hydrogen mixer is an essential part of converting the diesel engine to work under dual fuel mode (hydrogen-diesel) without any engine modification. In this study, the Air-hydrogen mixer is developed to get a homogenous mixture for hydrogen with air and a stoichiometric air-fuel ratio according to the speed of the engine. The mixer depends on the balance between the force exerted on the head surface of the valve and the opposite forces (the spring and friction forces) and its relation to decrease and increase the fuel inlet. Computational fluid dynamics (CFD) analysis software was utilised to study the hydrogen and airflow behaviour inside the mixer, established by 3.2 L engine. The Air-hydrogen mixer is examined with different speeds of engine1000, 2000, 3000 and 4000 RPM. Results showed air-hydrogen mixture was homogenous in the mixer. Furthermore, the stoichiometric air-fuel ratio was achieved according to the speed of the engine, the developed mixer of the AIR-Hydrogen mixing process provides high mixing homogeneity and engines with stoichiometric air-fuel ratios, which subsequently contributes to the high levels of efficiency in engine operation. In summary, the current study intends to reduce the emissions of gases and offer a wide range of new alternative fuels usage. While the performance of the diesel engine with the new air-hydrogen mixer needs to be tested practically.

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Comparative Evaluation of the Effect of Intake Charge Temperature, Pilot Fuel Quantity and Injection Advance on Dual Fuel Compression Ignition Engine Performance Characteristics and Emitted Pollutants

Volume 3: Combustion Science and Engineering ◽

10.1115/imece2009-10435 ◽

2009 ◽

Cited By ~ 7

Author(s):

Roussos G. Papagiannakis ◽

Theodoros C. Zannis ◽

Elias A. Yfantis ◽

Dimitrios T. Hountalas

Keyword(s):

Diesel Engine ◽

Natural Gas ◽

Diesel Fuel ◽

Diesel Engines ◽

High Speed ◽

Engine Performance ◽

Exhaust Emissions ◽

Performance Characteristics ◽

Dual Fuel ◽

Pilot Fuel

The simultaneous reduction of nitrogen oxide emissions and particulate matter in a compression ignition environment is quite difficult due to the soot/NOx trade off and it is often accompanied by fuel consumption penalties. Thus, fuel reformulation is also essential for the curtailment of diesel pollutant emissions along with the optimization of combustion-related design factors and exhaust after-treatment equipment. Various solutions have been proposed for improving the combustion process of conventional diesel engines and reducing the exhaust emissions without making serious modifications on the engine, one of which is the use of natural gas as a supplement for the conventional diesel fuel (Dual Fuel Natural Gas/Diesel Engines). Natural gas is considered to be quite promising since its cost is relative lower compared to conventional fuels and it has high auto-ignition temperature compared to other gaseous fuels facilitating thus its use on future and existing fleet of small high speed direct injection diesel engines without serious modifications on their structure. Moreover, natural gas does not generate particulates when burned in engines. The most common natural gas/diesel operating mode is referred to as the Pilot Ignited Natural Gas Diesel Engine (P.I.N.G.D.E). Here, the primary fuel is natural gas that controls the engine power output, while the pilot diesel fuel injected near the end of the compression stroke autoignites and creates ignition sources for the surrounding gaseous fuel mixture to be burned. Previous research studies have shown that the main disadvantage of this dual fuel combustion is its negative impact on engine efficiency compared to the normal diesel operation, while carbon monoxide emissions are also increased. The specific engine operating mode, in comparison with conventional diesel fuel operation, suffers from low brake engine efficiency and high carbon monoxide (CO) emissions. The influence becomes more evident at part load conditions. Intake charge temperature, pilot fuel quantity and injection advance are some of the engine parameters which influence significantly the combustion mechanism inside the combustion chamber of a Pilot Ignited Natural Gas Diesel Engine. In order to be examined the effect of these parameters on performance and exhaust emissions of a natural gas/diesel engine a theoretical investigation has been conducted by using a numerical simulation. In order to be examined the effect of increased air inlet temperature combined with increased pilot fuel quantity and its injection timing on performance and exhaust emissions of a pilot ignited natural gas-diesel engine, a theoretical investigation has been conducted by using a comprehensive two-zone phenomenological model. The results concerning engine performance characteristics and NO, CO and Soot emissions for various engine operating conditions (i.e. load and engine speed), comes from the employment of a comprehensive two-zone phenomenological model which had been applied on a high-speed natural gas/diesel engine. The main objectives of this comparative assessment are to record and to comparatively evaluate the relative impact each one of the above mentioned parameters on engine performance characteristics and emitted pollutants. Furthermore, the present investigation deals with the determining of optimum combinations between the parameters referred before since at high engine load conditions, the simultaneous increase some of the specific parameters may lead in undesirable results about engine performance characteristics. The conclusions of the specific investigation will be extremely valuable for the application of this technology on existing DI diesel engines.

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Investigation of Effect on Environmental Performance of Using LNG as Fuel for Engines in Seaport Tugboats

Journal of Marine Science and Engineering ◽

10.3390/jmse9020123 ◽

2021 ◽

Vol 9 (2) ◽

pp. 123

Author(s):

Sergejus Lebedevas ◽

Lukas Norkevičius ◽

Peilin Zhou

Keyword(s):

Diesel Engine ◽

Natural Gas ◽

Baltic Sea ◽

Impact Assessment ◽

Fuel Consumption ◽

Dual Fuel ◽

Nox Emissions ◽

The Baltic Sea ◽

Emission Analysis ◽

The Baltic

Decarbonization of ship power plants and reduction of harmful emissions has become a priority in the technological development of maritime transport, including ships operating in seaports. Engines fueled by diesel without using secondary emission reduction technologies cannot meet MARPOL 73/78 Tier III regulations. The MEPC.203 (62) EEDI directive of the IMO also stipulates a standard for CO2 emissions. This study presents the results of research on ecological parameters when a CAT 3516C diesel engine is replaced by a dual-fuel (diesel-liquefied natural gas) powered Wartsila 9L20DF engine on an existing seaport tugboat. CO2, SO2 and NOx emission reductions were estimated using data from the actual engine load cycle, the fuel consumption of the KLASCO-3 tugboat, and engine-prototype experimental data. Emission analysis was performed to verify the efficiency of the dual-fuel engine in reducing CO2, SO2 and NOx emissions of seaport tugboats. The study found that replacing a diesel engine with a dual-fuel-powered engine led to a reduction in annual emissions of 10% for CO2, 91% for SO2, and 65% for NOx. Based on today’s fuel price market data an economic impact assessment was conducted based on the estimated annual fuel consumption of the existing KLASCO-3 seaport tugboat when a diesel-powered engine is replaced by a dual-fuel (diesel-natural gas)-powered engine. The study showed that a 33% fuel costs savings can be achieved each year. Based on the approved methodology, an ecological impact assessment was conducted for the entire fleet of tugboats operating in the Baltic Sea ports if the fuel type was changed from diesel to natural gas. The results of the assessment showed that replacing diesel fuel with natural gas achieved 78% environmental impact in terms of NOx emissions according to MARPOL 73/78 Tier III regulations. The research concludes that new-generation engines on the market powered by environmentally friendly fuels such as LNG can modernise a large number of existing seaport tugboats, significantly reducing their emissions in ECA regions such as the Baltic Sea.

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