Efficacy of Add-On Hydrous Ethanol Dual Fuel Systems to Reduce NOx Emissions From Diesel Engines

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Jeffrey T. Hwang ◽  
Alex J. Nord ◽  
William F. Northrop
Keyword(s):  
Diesel Engines ◽  
Fuel Injection ◽  
Dual Fuel ◽  
Nox Emissions ◽  
Energy Fraction ◽  
No Formation ◽  
Peak Cylinder Pressure ◽  
Zone Modeling ◽  
Diesel Fuel Injection ◽  
Hydrous Ethanol

Aftermarket dual-fuel injection systems using a variety of different fumigants have been proposed as alternatives to expensive after-treatment to control NOx emissions from legacy diesel engines. However, our previous work has shown that available add-on systems using hydrous ethanol as the fumigant achieve only minor benefits in emissions without recalibration of the diesel fuel injection strategy. This study experimentally re-evaluates a novel aftermarket dual-fuel port fuel injection (PFI) system used in our previous work, with the addition of higher flow injectors to increase the fumigant energy fraction (FEF), defined as the ratio of energy provided by the hydrous ethanol on a lower heating value (LHV) basis to overall fuel energy. Results of this study confirm our earlier findings that as FEF increases, NO emissions decrease, while NO2 and unburned ethanol emissions increase, leading to no change in overall NOx. Peak cylinder pressure and apparent rates of heat release are not strongly dependent on FEF, indicating that in-cylinder NO formation rates by the Zel'dovich mechanism remain the same. Through single zone modeling, we show the feasibility of in-cylinder NO conversion to NO2 aided by unburned ethanol. The modeling results indicate that NO to NO2 conversion occurs during the early expansion stroke where bulk gases have temperature in the range of 1150–1250 K. This work conclusively proves that aftermarket dual fuel systems for fixed calibration diesel engines cannot reduce NOx emissions without lowering peak temperature during diffusive combustion responsible for forming NO in the first place.

Efficacy of Add-On Hydrous Ethanol Dual Fuel Systems to Reduce NOx Emissions From Diesel Engines

2016 ◽  
Author(s):  
Jeffrey T. Hwang ◽  
Alex J. Nord ◽  
William F. Northrop
Keyword(s):  
Diesel Engines ◽  
Fuel Injection ◽  
Dual Fuel ◽  
Nox Emissions ◽  
Energy Fraction ◽  
No Formation ◽  
Peak Cylinder Pressure ◽  
Zone Modeling ◽  
Diesel Fuel Injection ◽  
Hydrous Ethanol

Aftermarket dual-fuel injection systems using a variety of different fumigants have been proposed as alternatives to expensive after-treatment to control NOX emissions from legacy diesel engines. However, our previous work has shown that available add-on systems using hydrous ethanol as the fumigant achieve only minor benefits in emissions without recalibration of the diesel fuel injection strategy. This study experimentally re-evaluates a novel aftermarket dual-fuel port fuel injection (PFI) system used in our previous work, with the addition of higher flow injectors to increase the fumigant energy fraction (FEF), defined as the ratio of energy provided by the hydrous ethanol on a lower heating value (LHV) basis to overall fuel energy. Results of this study confirm our earlier findings that as FEF increases, NO emissions decrease, while NO2 and unburned ethanol emissions increase, leading to no change in overall NOX. Peak cylinder pressure and apparent rates of heat release are not strongly dependent on FEF, indicating that in-cylinder NO formation rates by the Zel’dovich mechanism remains the same. Through single zone modeling, we show the feasibility of in-cylinder NO conversion to NO2 aided by unburned ethanol. The modeling results indicate that NO to NO2 conversion occurs during the early expansion stroke where bulk gases have temperature in the range of 1150–1250 K. This work conclusively proves that aftermarket dual fuel systems for fixed calibration diesel engines cannot reduce NOX emissions without lowering peak temperature during diffusive combustion responsible for forming NO in the first place.

Emissions From a Diesel Engine Operating in a Dual-Fuel Mode Using Port-Fuel Injection of Heated Hydrous Ethanol

2015 ◽  
Author(s):  
Alex J. Nord ◽  
Jeffrey T. Hwang ◽  
William F. Northrop
Keyword(s):  
Fuel Injection ◽  
Heating System ◽  
Dual Fuel ◽  
Tier 2 ◽  
Energy Fraction ◽  
Operating Modes ◽  
Port Fuel Injection ◽  
Lower Heating Value ◽  
Fuel Vaporization ◽  
Hydrous Ethanol

Aftermarket dual-fuel injection systems in diesel engines using hydrous ethanol have been developed as a means to lower emissions from older diesel-powered equipment. However, our previous work has shown that the emissions benefits of currently available aftermarket intake fumigation injection systems can be inconsistent with manufacturer claims. Our current study evaluates a newly developed aftermarket dual fuel system that incorporates a novel fuel heating system and port fuel injection (PFI). This paper describes an experimental investigation of engine-out emissions from a John Deere 4045HF475 Tier 2 engine with port injection of 180 proof (90% ethanol by volume) hydrous ethanol. The engine was retrofitted with a custom fuel heat exchanger to heat the hydrous ethanol to a range of 46–79°C for helping to improve fuel vaporization in the intake port. PFI duration was controlled using engine speed and throttle position as inputs to achieve a desired fumigant energy fraction (FEF), defined as the amount of energy provided by the hydrous ethanol based on lower heating value (LHV) over the total fuel energy provided to the engine. Data was collected over a range of FEF with direct injected diesel for eight operating modes comparing heated versus unheated hydrous ethanol. Results of the study indicate that as FEF increases, NO emissions decrease, while NO2, CO, THC, and ethanol emissions increase. In addition, it was found that preheating the ethanol using engine coolant prior to injection has little benefit on engine-out emissions. The work shows that the implemented aftermarket dual-fuel PFI system can achieve FEF rates up to 37% at low engine load while yielding modest benefits in emissions.

Emissions From a Diesel Engine Operating in a Dual-Fuel Mode Using Port-Fuel Injection of Heated Hydrous Ethanol

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Alex J. Nord ◽  
Jeffrey T. Hwang ◽  
William F. Northrop
Keyword(s):  
Fuel Injection ◽  
Heating System ◽  
Dual Fuel ◽  
Tier 2 ◽  
Energy Fraction ◽  
Operating Modes ◽  
Port Fuel Injection ◽  
Lower Heating Value ◽  
Fuel Vaporization ◽  
Hydrous Ethanol

Aftermarket dual-fuel injection systems in diesel engines using hydrous ethanol as secondary fuel have been developed as a means to lower emissions from older diesel-powered equipment. However, our previous work has shown that the emissions benefits of currently available aftermarket intake fumigation injection systems can be inconsistent with manufacturer claims. Our current study evaluates a newly developed aftermarket dual-fuel system that incorporates a fuel heating system and port fuel injection (PFI). This paper describes an experimental investigation of engine-out emissions from a John Deere 4045HF475 Tier 2 engine with port injection of 180 proof (90% ethanol by volume) hydrous ethanol. The engine was retrofitted with a custom fuel heat exchanger to heat the hydrous ethanol to a range of 46–79 °C for helping to improve fuel vaporization in the intake port. PFI duration was controlled using engine speed and throttle position as inputs to achieve a desired fumigant energy fraction (FEF), defined as the amount of energy provided by the hydrous ethanol based on lower heating value (LHV) over the total fuel energy provided to the engine. Data was collected over a range of FEF with direct injected diesel for eight operating modes comparing heated versus unheated hydrous ethanol. Results of the study indicate that as FEF increases, NO emissions decrease, while NO2, CO, THC, and unburned ethanol emissions increase. In addition, it was found that preheating the ethanol using engine coolant prior to injection has little benefit on engine-out emissions. The work shows that the implemented aftermarket dual-fuel PFI system can achieve FEF rates up to 37% at low engine load while yielding modest benefits in emissions.

Development of a Phenomenological Combustion Simulation for a Dual Fuel Engine

2001 ◽  
Author(s):  
Yafeng Liu ◽  
Stuart R. Bell ◽  
K. Clark Midkiff
Keyword(s):  
Natural Gas ◽  
Diesel Fuel ◽  
Fuel Injection ◽  
Air Entrainment ◽  
Dual Fuel ◽  
Nox Emissions ◽  
Cycle Simulation ◽  
Specific Performance ◽  
Combustion Simulation ◽  
Reduce Emissions

Abstract A phenomenological cycle simulation for a dual fuel engine has been developed to mathematically simulate the significant processes of the engine cycle, to predict specific performance parameters for the engine, and to investigate approaches to improve performance and reduce emissions. The simulation employs two zones (crevice and unburned) during the processes of exhaust, intake, compression before fuel injection starts, and expansion after combustion ends. From the start of fuel injection to the end of combustion, several, zones are utilized to account for crevice flow, diesel fuel spray, air entrainment, diesel fuel droplet evaporation, ignition delay, flame propagation, and combustion quenching. The crevice zone absorbs charge gas from the cylinder as pressure increases, and releases mass back into the chamber as pressure decreases. Some crevice mass released during late combustion may not be oxidized, resulting in emissions of hydrocarbon and carbon monoxide. Quenching ahead of the flame front may leave additional charge unburned, yielding high methane emissions. Potential reduction of engine-out NOx emissions with natural gas fueling has also been investigated. The higher substitution of natural gas in the engine produces less engine-out NOx emissions. This paper presents the development of the model, baseline predictions, and comparisons to experimental measurements performed in a single-cylinder Caterpillar 3400 series engine.

scholarly journals Comparative Analysis of Combustion Stability of Diesel/Ethanol Utilization by Blend and Dual Fuel

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 946 ◽  
Author(s):  
Wojciech Tutak ◽  
Arkadiusz Jamrozik
Keyword(s):  
Diesel Fuel ◽  
Fuel Injection ◽  
Combustion Process ◽  
Combustion Stability ◽  
Dual Fuel ◽  
Maximum Pressure ◽  
Compression Ignition Engine ◽  
Energy Fraction ◽  
Pure Ethanol ◽  
Advantages And Disadvantages

The aim of the work is a comparison of two combustion systems of fuels with different reactivity. The first is combustion of the fuel mixture and the second is combustion in a dual-fuel engine. Diesel fuel was burned with pure ethanol. Both methods of co-firing fuels have both advantages and disadvantages. Attention was paid to the combustion stability aspect determined by COVIMEP as well as the probability density function of IMEP. It was analyzed also the spread of the maximum pressure value, the angle of the position of maximum pressure. The influence of ethanol on ignition delay time spread and end of combustion process was evaluated. The experimental investigation was conducted on 1-cylinder air cooled compression ignition engine. The test engine operated with constant rpm equal to 1500 rpm and constant angle of start of diesel fuel injection. The engine was operated with ethanol up to 50% of its energy fraction.

scholarly journals Use of biogas to power diesel engines with common rail fuel systems

2018 ◽  
Vol 182 ◽  
pp. 01018
Author(s):  
Sławomir Wierzbicki ◽  
Michał Śmieja
Keyword(s):  
Diesel Engines ◽  
Alternative Energy ◽  
Liquid Fuel ◽  
Fossil Fuels ◽  
Fuel Injection ◽  
Raw Materials ◽  
Common Rail ◽  
Dual Fuel ◽  
Alternative Energy Sources ◽  
Study Results

The limited resources of fossil fuels, as well as the search for a reduction in emissions of carbon dioxide and other toxic compounds to the atmosphere have prompted the search for new, alternative energy sources. One of the potential fuels which may be widely used in the future as a fuel is biogas which can be obtained from various types of raw materials. The article presents selected results as regards the effects of the proportion of biogas of various compositions on the course of combustion in a dual-fuel diesel engine with a Common Rail fuel system. The presented study results indicate the possibility for the use of fuels of this type in diesel engines; although changes are necessary in the manner of controlling liquid fuel injection.

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