Improved Thermal Efficiency Using Hydrous Ethanol Reforming in SI Engines

2013 ◽  
Author(s):  
Atsushi Shimada ◽  
Takao Ishikawa
Keyword(s):  
Thermal Efficiency ◽  
Ethanol Reforming ◽  
Si Engines ◽  
Hydrous Ethanol

scholarly journals Experimental Research on Controllability and Emissions of Jet-Controlled Compression Ignition Engine

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2936 ◽  
Author(s):  
Hua Tian ◽  
Jingchen Cui ◽  
Tianhao Yang ◽  
Yao Fu ◽  
Jiangping Tian ◽  
...  
Keyword(s):  
Thermal Efficiency ◽  
High Speed ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Engine Emissions ◽  
Spark Timing ◽  
Crank Angle ◽  
Marine Engines ◽  
Si Engines ◽  
Ci Engines

Low-temperature combustions (LTCs), such as homogeneous charge compression ignition (HCCI), could achieve high thermal efficiency and low engine emissions by combining the advantages of spark-ignited (SI) engines and compression-ignited (CI) engines. Robust control of the ignition timing, however, still remains a hurdle to practical use. A novel technology of jet-controlled compression ignition (JCCI) was proposed to solve the issue. JCCI combustion phasing was controlled by hot jet formed from pre-chamber spark-ignited combustion. Experiments were done on a modified high-speed marine engine for JCCI characteristics research. The JCCI principle was verified by operating the engine individually in the mode of JCCI and in the mode of no pre-chamber jet under low- and medium-load working conditions. Effects of pre-chamber spark timing and intake charge temperature on JCCI process were tested. It was proven that the combustion phasing of the JCCI engine was closely related to the pre-chamber spark timing. A 20 °C temperature change of intake charge only caused a 2° crank angle change of the start of combustion. Extremely low nitrogen oxides (NOx) emission was achieved by JCCI combustion while keeping high thermal efficiency. The JCCI could be a promising technology for dual-fuel marine engines.

An Experimental Investigation of Reactivity-Controlled Compression Ignition Combustion in a Single-Cylinder Diesel Engine Using Hydrous Ethanol

2014 ◽  
Vol 137 (3) ◽  
Author(s):  
Wei Fang ◽  
Junhua Fang ◽  
David B. Kittelson ◽  
William F. Northrop
Keyword(s):  
Experimental Investigation ◽  
Diesel Engine ◽  
Thermal Efficiency ◽  
Alternative Fuels ◽  
Compression Ignition ◽  
Reactivity Controlled Compression Ignition ◽  
Single Cylinder ◽  
Diesel Injection ◽  
Soot Emissions ◽  
Hydrous Ethanol

Dual-fuel reactivity-controlled compression ignition (RCCI) combustion using port injection of a less reactive fuel and early-cycle direct injection (DI) of a more reactive fuel has been shown to yield both high thermal efficiency and low NOX and soot emissions over a wide engine operating range. Conventional and alternative fuels such as gasoline, natural gas, and E85 as the lower reactivity fuel in RCCI have been studied by many researchers; however, published experimental investigations of hydrous ethanol use in RCCI are scarce. Making greater use of hydrous ethanol in internal combustion engines has the potential to dramatically improve the economics and life cycle carbon dioxide emissions of using bioethanol. In this work, an experimental investigation was conducted using 150 proof hydrous ethanol as the low reactivity fuel and commercially available diesel as the high reactivity fuel in an RCCI combustion mode at various load conditions. A modified single-cylinder diesel engine was used for the experiments. Based on previous studies on RCCI combustion by other researchers, early-cycle split-injection strategy of diesel fuel was used to create an in-cylinder fuel reactivity distribution to maintain high thermal efficiency and low NOX and soot emissions. At each load condition, timing and mass fraction of the first diesel injection was held constant, while timing of the second diesel injection was swept over a range where stable combustion could be maintained. Since hydrous ethanol is highly resistant to auto-ignition and has large heat of vaporization, intake air heating was needed to obtain stable operations of the engine. The study shows that 150 proof hydrous ethanol can be used as the low reactivity fuel in RCCI through 8.6 bar indicated mean effective pressure (IMEP) and with ethanol energy fraction up to 75% while achieving simultaneously low levels of NOX and soot emissions. With increasing engine load, less intake heating is needed and exhaust gas recirculation (EGR) is required to maintain low NOX emissions.

Effect of Ethanol on Part Load Thermal Efficiency and CO2 Emissions of SI Engines

2013 ◽  
Vol 6 (1) ◽  
pp. 456-469 ◽  
Author(s):  
Hosuk H. Jung ◽  
Michael H. Shelby ◽  
Charles E. Newman ◽  
Robert A. Stein
Keyword(s):  
Co2 Emissions ◽  
Thermal Efficiency ◽  
Part Load ◽  
Si Engines

An Experimental Investigation of Reactivity-Controlled Compression Ignition Combustion in a Single-Cylinder Diesel Engine Using Hydrous Ethanol

2013 ◽  
Author(s):  
Wei Fang ◽  
David B. Kittelson ◽  
William F. Northrop ◽  
Junhua Fang
Keyword(s):  
Experimental Investigation ◽  
Diesel Engine ◽  
Thermal Efficiency ◽  
Compression Ignition ◽  
Reactivity Controlled Compression Ignition ◽  
Engine Load ◽  
Single Cylinder ◽  
Diesel Injection ◽  
Soot Emissions ◽  
Hydrous Ethanol

Dual-fuel reactivity-controlled compression ignition (RCCI) combustion using port injection of a less reactive fuel and early-cycle direct injection of a more reactive fuel has been shown to yield both high thermal efficiency and low NOX and soot emissions over a wide engine operating range. Conventional and alternative fuels such as gasoline, natural gas and E85 as the lower reactivity fuel in RCCI have been studied by many researchers; however, published experimental investigations of hydrous ethanol use in RCCI are scarce. Making greater use of hydrous ethanol in internal combustion engines has the potential to dramatically improve the economics and life cycle carbon dioxide emissions of using bio-ethanol. In this work, an experimental investigation was conducted using 150 proof hydrous ethanol as the low reactivity fuel and commercially-available diesel as the high reactivity fuel in an RCCI combustion mode at various load conditions. A modified single-cylinder diesel engine was used for the experiments. Based on previous studies on RCCI combustion by other researchers, early-cycle split-injection strategy of diesel fuel was used to create an in-cylinder fuel reactivity distribution to maintain high thermal efficiency and low NOX and soot emissions. At each load condition, timing and mass fraction of the first diesel injection was held constant, while timing of the second diesel injection was swept over a range where stable combustion could be maintained. Since hydrous ethanol is highly resistant to auto-ignition and has large heat of vaporization, intake air heating was needed to obtain stable operations of the engine. The study shows that 150 proof hydrous ethanol can be used as the low reactivity fuel in RCCI through 8.6 bar IMEP and with ethanol energy fraction up to 75% while achieving simultaneously low levels of NOX and soot emissions. With increasing engine load, less intake heating is needed and EGR is required to maintain low NOX emissions. Future work will look at stability of hydrous ethanol RCCI at higher engine load.

scholarly journals The Influence of Charge Motion on Pre-Chamber and Main Chamber Combustion in a Highly Dilute Jet Ignition Engine

2021 ◽  
Vol 6 ◽  
Author(s):  
Michael Bunce ◽  
Alasdair Cairns ◽  
Sai Krishna Pothuraju Subramanyam ◽  
Nathan Peters ◽  
Hugh Blaxill
Keyword(s):  
Thermal Efficiency ◽  
Internal Combustion Engines ◽  
System Optimization ◽  
Combustion Stability ◽  
Main Chamber ◽  
Charge Motion ◽  
Ignition System ◽  
Lean Combustion ◽  
Si Engines ◽  
The Impact

Though there are multiple viable powertrain options available for the automotive sector, those that contain internal combustion engines will continue to account for the majority of global sales for the next several decades. It is therefore imperative to continue the pursuit of novel combustion concepts that produce efficiency levels significantly higher than those of current engines. Introducing high levels of dilution in spark ignited (SI) engines has consistently proven to produce an efficiency benefit compared to conventional stoichiometric engine operation. However, this combustion mode can present challenges for the ignition system. Pre-chamber jet ignition enables stable, highly dilute combustion by both increasing the ignition energy present in the system and distributing it throughout the combustion chamber. Previous work by the authors have shown that jet ignition produces 15–25% increases in thermal efficiency over baseline SI engines with only relatively minor changes to engine architecture. Lean combustion in general and jet ignition in particular represent fundamentally different engine operating modes compared to those of conventional stoichiometric SI engines. Therefore, there are some system sensitivities not present in stoichiometric engines that must be investigated in order to fully optimize the jet ignition system. Differing types and magnitudes of charge motion are incorporated in SI engines to aid with mixture preparation but the influence of charge motion over lean combustion performance, particularly in jet ignition engines, is less well understood. This study analyzes the impact that charge motion has on both pre-chamber and main chamber combustion. A 1.5 L 3-cylinder gasoline engine is outfitted with multiple intake port configurations producing varying magnitudes and types of charge motion. Pre-chamber and main chamber combustion stability and other burn parameter responses are analyzed across multiple speeds and loads, including at critical operating points such as a catalyst heating condition. The results show that there is combustion sensitivity to charge motion, resulting in >1 percentage point spread in peak thermal efficiency for the configurations tested, and that this sensitivity manifests most significantly under low ignitability conditions such as heavy dilution. These results provide guidance for future system optimization of jet ignition engines.

scholarly journals Effect of Acetone-n-Butanol-Ethanol (ABE) as an Oxygenate on Combustion, Performance, and Emission Characteristics of a Spark Ignition Engine

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Gang Wu ◽  
Deng Wu ◽  
Yuelin Li ◽  
Lei Meng
Keyword(s):  
Thermal Efficiency ◽  
Alternative Fuel ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Pollutant Emissions ◽  
Emission Characteristics ◽  
Brake Thermal Efficiency ◽  
Performance And Emission ◽  
Combustion Performance ◽  
Si Engines

Ethanol is the most extensively used oxygenate for spark ignition (SI) engines. In comparison with ethanol, n-butanol exhibits a number of desirable properties for use in SI engines, which has proved to be a very promising oxygenated alternative fuel in recent years. However, the dehydration and recovery of bio-n-butanol consume extra money and energy in the acetone-n-butanol-ethanol (ABE) fermentation process. Hence, we focus on the research of ABE as a potential oxygenated alternative fuel in SI engines. The combustion, performance, and emission characteristics of B30, E30, ABE30 (i.e., 30 vol.% n-butanol, ethanol, and ABE blended with 70 vol.% gasoline), and G100 (pure gasoline) were compared in this study. The comparison results between B30, E30, and ABE30 at stoichiometric conditions show that ABE30 presents retarded combustion phasing, higher brake thermal efficiency, lower CO emissions, higher UHC emissions, and similar NOx emissions. In comparison with G100 under various engine loads and equivalence ratios, for the most part, ABE30 exhibits 1.4% higher brake thermal efficiency, 14% lower carbon monoxide, 9.7% lower unburned hydrocarbons, and 23.4% lower nitrogen oxides. It is indicated that ABE could be served as the oxygenate in spark ignition engine due to its capability to improve energy efficiency and reduce pollutant emissions.

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