Effects of ammonia energy fraction and diesel injection timing on combustion and emissions of an ammonia/diesel dual-fuel engine

Fuel ◽  
2021 ◽  
pp. 122723
Author(s):  
Amin Yousefi ◽  
Hongsheng Guo ◽  
Shouvik Dev ◽  
Brian Liko ◽  
Simon Lafrance
Keyword(s):  
Dual Fuel ◽  
Injection Timing ◽  
Energy Fraction ◽  
Diesel Injection

Dual-Fuel Diesel Engine Combustion With Hydrogen, Gasoline, and Ethanol as Fumigants: Effect of Diesel Injection Timing

2014 ◽  
Vol 136 (8) ◽  
Author(s):  
Wei Fang ◽  
Bin Huang ◽  
David B. Kittelson ◽  
William F. Northrop
Keyword(s):  
Diesel Engine ◽  
Alternative Fuels ◽  
Research Effort ◽  
Dual Fuel ◽  
Injection Timing ◽  
Energy Fraction ◽  
Rail Systems ◽  
Diesel Injection ◽  
Hc Emissions ◽  
Cycle Efficiency

Premixed compression ignition (CI) combustion has attracted increasing research effort recently due to its potential to achieve both high thermal efficiency and low emissions. Dual-fuel strategies for enabling premixed CI have been a focus using a low-reactivity fumigant and direct diesel injection to control ignition. Alternative fuels like hydrogen and ethanol have been used as fumigants in the past but typically with diesel injection systems that did not allow the same degree of control or mixing enabled by modern common rail systems. In this work, we experimentally investigated hydrogen, ethanol, and gasoline as fumigants and examined three levels of fumigant energy fraction (FEF) using gasoline over a large, direct diesel injection timing range with a single-cylinder diesel engine. It was found that the operable diesel injection timing range at constant FEF was dependent on the fumigant's propensity for autoignition. Peak indicated gross cycle efficiency occurred with advanced diesel injection timing and aligned well with combustion phasing near top dead center (TDC), as we found in an earlier work. The use of hydrogen as a fumigant resulted in very low hydrocarbon (HC) emissions compared with ethanol and gasoline, establishing that they mainly result from incomplete combustion of the fumigated fuel. Hydrogen emissions were independent of diesel injection timing, and HC emissions were strongly linked to combustion phasing, giving further indication that squish and crevice flows are responsible for partially burned species from fumigation combustion.

Dual-Fuel Diesel Engine Combustion With Hydrogen, Gasoline and Ethanol as Fumigants: Effect of Diesel Injection Timing

2012 ◽  
Author(s):  
Wei Fang ◽  
Bin Huang ◽  
David B. Kittelson ◽  
William F. Northop
Keyword(s):  
Diesel Engine ◽  
Alternative Fuels ◽  
Research Effort ◽  
Dual Fuel ◽  
Injection Timing ◽  
Energy Fraction ◽  
Rail Systems ◽  
Diesel Injection ◽  
Hc Emissions ◽  
Cycle Efficiency

Premixed compression ignition (CI) combustion has attracted increasing research effort recently due to its potential to achieve both high thermal efficiency and low emissions. Dual-fuel strategies for enabling premixed CI have been a focus using a low reactivity fumigant and direct diesel injection to control ignition. Alternative fuels like hydrogen and ethanol have been used as fumigants in the past but typically with diesel injection systems that did not allow the same degree of control or mixing enabled by modern common rail systems. In this work we experimentally investigated hydrogen, ethanol and gasoline as fumigants and examined three levels of fumigant energy fraction (FEF) using gasoline over a large direct diesel injection timing range with a single cylinder diesel engine. It was found that the operable diesel injection timing range at constant FEF was dependent on the fumigant’s propensity for autoignition. Peak indicated gross cycle efficiency occurred with advanced diesel injection timing and aligned well with combustion phasing near TDC as we found in an earlier work. The use of hydrogen as a fumigant resulted in very low HC emissions compared with ethanol and gasoline, establishing that they mainly result from incomplete combustion of the fumigated fuel. Hydrogen emissions were independent of diesel injection timing and HC emissions were strongly linked to combustion phasing, giving further indication that squish and crevice flows are responsible for partially burned species from fumigation combustion.

Optimization of Pilot Diesel Injection Timing on Load Variation Dual Fuel Diesel-CNG Engine on Combustions and Emissions Characteristics

2019 ◽  
Vol 13 (1) ◽  
pp. 58 ◽  
Author(s):  
Bambang Sudarmanta ◽  
Atok Setiyawan ◽  
Ary Bachtiar K. Putra ◽  
Dori Yuvenda ◽  
Jose Da Silva
Keyword(s):  
Dual Fuel ◽  
Injection Timing ◽  
Load Variation ◽  
Diesel Injection ◽  
Cng Engine

Combustion Performance and Unburned Hydrocarbon Emissions of a Natural Gas–Diesel Dual Fuel Engine at a Low Load Condition

2017 ◽  
Author(s):  
Hongsheng Guo ◽  
Brian Liko ◽  
Luis Luque ◽  
Jennifer Littlejohns
Keyword(s):  
Natural Gas ◽  
Internal Combustion Engines ◽  
Load Condition ◽  
Fuel Combustion ◽  
Dual Fuel ◽  
Injection Timing ◽  
Unburned Hydrocarbon ◽  
Diesel Injection ◽  
Dual Fuel Engines ◽  
Dual Fuel Combustion

The combustion of natural gas reduces fuel cost and generates less emissions of carbon dioxide and particulate matter than diesel and gasoline. Replacing diesel by natural gas in internal combustion engines is of great interest for transportation and stationary power generation. Dual fuel combustion is an efficient way to burn natural gas in internal combustion engines. In natural gas–diesel dual fuel engines, unburned hydrocarbon emissions increase with increasing natural gas fraction. Many studies have been conducted to improve the performance of natural gas–diesel dual fuel engines and reported the performance of combustion and emissions of regulated pollutants and total unburned hydrocarbon at various engine operating strategies. However, little has been reported on the emissions of different unburned hydrocarbon components. In this paper, an experimental investigation was conducted to investigate the combustion performance and emissions of various unburned hydrocarbon components, including methane, ethane, ethylene, acetylene, propylene, formaldehyde, acetaldehyde and benzaldehyde, at a low engine load condition. The operating conditions, such as engine speed, load, intake temperature and pressure, were well controlled during the experiment. The combustion and emissions performance of pure diesel and natural gas–diesel dual fuel combustion were compared. The effect of diesel injection timing was analyzed. The results show that appropriately advancing diesel injection timing to form a homogeneous charge compression ignition-like combustion is beneficial to natural gas–diesel dual fuel combustion at low load conditions. The emissions of different unburned hydrocarbon components changed in dual fuel combustion, with emissions of some unburned hydrocarbon components being primarily due to the combustion of natural gas, while those of others being more related to diesel combustion.

Theoretical Analyses of Heat Balance in a Diesel/Natural Gas Dual-Fuel Engine at Low and Medium Loads Based on Experimental Values

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Zhongshu Wang ◽  
Guizhi Du ◽  
Ming Li ◽  
Yun Xu ◽  
Fangyuan Zhang
Keyword(s):  
Heat Transfer ◽  
Natural Gas ◽  
Thermal Efficiency ◽  
Hot Water ◽  
Energy Utilization ◽  
Dual Fuel ◽  
Exergy Destruction ◽  
Energy Fraction ◽  
Combustion Heat ◽  
Diesel Injection

Abstract In order to propose the control strategies based on exergy to realize efficient and energy-saving operation of the engine, the energy and exergy balance under sensitive boundary conditions were analyzed with the first and second laws of thermodynamics on a six-cylinders, four strokes, turbocharged, intercooled, and high-pressure common rail diesel/natural gas (NG) dual-fuel engine in this paper. The results depicted that the thermal efficiency and exergy efficiency decrease with the increase of NG percentage energy substitution rate (PES). Compared with other conditions, at medium load, 1978 rpm and 90% PES, the exergy destruction caused by irreversibility process including mixing combustion, heat transfer and mechanical friction reaches 72.33%. With the advance of diesel injection time (Tinj), thermal efficiency and energy fraction of heat transfer increase first and then decrease. However, diesel injection pressure (Pinj) has little effect on improving energy utilization. Compared with single diesel injection, appropriate multiple diesel injection can improve combustion performance and energy utilization. When the first Tinj is 35 deg CA BTDC and second Tinj is 25 deg CA BTDC, nearly 50% of the energy lost in heat transfer can be converted into useful work. The lost exergy can be reduced by choosing appreciate Tinj and Pinj, adding exhaust gas recirculation (EGR) to reduce in-cylinder temperature to improve combustion and using thermal insulation materials to reduce heat transfer or using the lost heat in other processes such as preheating intake air and producing the hot water or steam of external consumption to reduce the exergy destruction.

Diesel-Like Efficiency Using Compressed Natural Gas/Diesel Dual-Fuel Combustion

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Karthik Nithyanandan ◽  
Jiaxiang Zhang ◽  
Yuqiang Li ◽  
Xiangyu Meng ◽  
Robert Donahue ◽  
...  
Keyword(s):  
Natural Gas ◽  
Substitution Rate ◽  
Fuel Combustion ◽  
Dual Fuel ◽  
Injection Timing ◽  
Diesel Combustion ◽  
Compressed Natural Gas ◽  
Diesel Injection ◽  
Dual Fuel Combustion ◽  
Ci Engines

The use of natural gas in compression ignition (CI) engines as a supplement to diesel under dual-fuel combustion mode is a promising technique to increase efficiency and reduce emissions. In this study, the effect of dual-fuel operating mode on combustion characteristics, engine performance and pollutant emissions of a diesel engine using natural gas as primary fuel and neat diesel as pilot fuel, has been examined. Natural gas (99% methane) was port injected into an AVL 5402 single cylinder diesel research engine under various engine operating conditions and up to 90% substitution was achieved. In addition, neat diesel was also tested as a baseline for comparison. The experiments were conducted at three different speeds—1200, 1500, and 2000 rpm, and at different diesel-equivalent loads (injection quantity)—15, 20 (7 bar IMEP), and 25 mg/cycle. Both performance and emissions data are presented and discussed. The performance was evaluated through measurements of in-cylinder pressure, power output and various exhaust emissions including unburned hydrocarbons (UHCs), carbon monoxide (CO), nitrogen oxides (NOx), and soot. The goal of these experiments was to maximize the efficiency. This was done as follows—the compressed natural gas (CNG) substitution rate (based on energy) was increased from 30% to 90% at fixed engine conditions, to identify the optimum CNG substitution rate. Then using that rate, a main injection timing sweep was performed. Under these optimized conditions, combustion behavior was also compared between single, double, and triple injections. Finally, a load and speed sweep at the optimum CNG rate and timings were performed. It was found that a 70% CNG substitution provided the highest indicated thermal efficiency (ITE). It appears that dual-fuel combustion has a maximum brake torque (MBT) diesel injection timing for different conditions which provides the highest torque. Based on multiple diesel injection tests, it was found that the conditions that favor pure diesel combustion, also favor dual-fuel combustion because better diesel combustion provides better ignition and combustion for the CNG-air mixture. For 70% CNG dual-fuel combustion, multiple diesel injections showed an increase in the efficiency. Based on the experiments conducted, diesel-CNG dual-fuel combustion is able to achieve similar efficiency and reduced emissions relative to pure diesel combustion. As such, CNG can be effectively used to substitute for diesel fuel in CI engines.

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