The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Shuli Zhao - One of the best experts on this subject based on the ideXlab platform.
-
performance and emission characteristics of a turbocharged spark Ignition hydrogen enriched compressed natural gas engine under wide open throttle operating conditions
International Journal of Hydrogen Energy, 2010Co-Authors: Mingyue Wang, Jiao Deng, Long Jiang, Nashay Naeve, Renzhe Chen, Shuli ZhaoAbstract:This paper investigates the effect of various hydrogen ratios in HCNG (hydrogen-enriched compressed natural gas) fuels on performance and emission characteristics at wide open throttle operating conditions using a turbocharged spark-Ignition natural gas engine. The experimental data was taken at hydrogen fractions of 0%, 30% and 55% by volume and was conducted under different excess air ratio (λ) at MBT operating conditions. It is found that under various λ, the addition of hydrogen can significantly reduce CO, CH4 emissions and the NOx emission remain at an acceptable level when Ignition Timing is optimized. Using the same excess air ratio, as more hydrogen is added the power, exhaust temperatures and max cylinder pressure decrease slowly until the mixture’s lower heating value remains unchanged with the hydrogen enrichment, then they rise gradually. In addition, the early flame development period and the flame propagation duration are both shorter, and the indicated thermal efficiency and maximum heat release rate both increase with more hydrogen addition.
-
performance and emission characteristics of a turbocharged cng engine fueled by hydrogen enriched compressed natural gas with high hydrogen ratio
International Journal of Hydrogen Energy, 2010Co-Authors: Mingyue Wang, Jiao Deng, Long Jiang, Nashay Naeve, Renzhe Chen, Shuli ZhaoAbstract:Abstract This paper investigates the effect of high hydrogen volumetric ratio of 55% on performance and emission characteristics in a turbocharged lean burn natural gas engine. The experimental data was conducted under various operating conditions including different spark Timing, excess air ratio (lambda), and manifold pressure. It is found that the addition of hydrogen at a high volumetric ratio could significantly extend the lean burn limit, improve the engine lean burn ability, decrease burn duration, and yield higher thermal efficiency. The CO, CH 4 emissions were reduced and NO x emission could be kept an acceptable low level with high hydrogen content under lean burn conditions when Ignition Timing were optimized.
Zhen Huang - One of the best experts on this subject based on the ideXlab platform.
-
experimental study on partially premixed compression Ignition combustion fueled with a low octane number primary reference fuel using two stage fuel supplying
International Journal of Engine Research, 2016Co-Authors: Yong Qian, Xiaole Wang, Zhen HuangAbstract:An experimental study of partially premixed compression Ignition combustion with low octane fuel was conducted on a single-cylinder engine. The effects of the external exhaust gas recirculation and intake boost on this partially premixed compression Ignition combustion and emissions were investigated. During the experiments, a trade-off relationship between the NOx and smoke emissions was observed in this partially premixed compression Ignition combustion. However, heavy exhaust gas recirculation usage has the potential to decrease NOx and soot emissions simultaneously at the expense of the fuel economy. It is determined that at an increased intake port pressure, the maximum in-cylinder pressure increases, and the Ignition Timing of the high-temperature combustion is retarded. Also, the peak value of the low-temperature combustion is slightly depressed, the peak value of the high-temperature heat release decreases significantly, and the maximum value of the diffusing burn increases to some extent. Compare...
-
experimental study and chemical analysis of n heptane homogeneous charge compression Ignition combustion with port injection of reaction inhibitors
Combustion and Flame, 2007Co-Authors: Yuchun Hou, Cheng Huang, Zhen HuangAbstract:The control of Ignition Timing in the homogeneous charge compression Ignition (HCCI) of n-heptane by port injection of reaction inhibitors was studied in a single-cylinder engine. Four suppression additives, methanol, ethanol, isopropanol, and methyl tert-butyl ether (MTBE), were used in the experiments. The effectiveness of inhibition of HCCI combustion with various additives was compared under the same equivalence ratio of total fuel and partial equivalence ratio of n-heptane. The experimental results show that the suppression effectiveness increases in the order MTBE < isopropanolethanol < methanol. But ethanol is the best additive when the oper- ating ranges, indicated thermal efficiency, and emissions are considered. For ethanol/n-heptane HCCI combustion, partial combustion may be observed when the mole ratio of ethanol to that of total fuel is larger than 0.20; mis- fires occur when the mole ratio of ethanol to that of total fuel larger than 0.25. Moreover, CO emissions strongly depend on the maximum combustion temperature, while HC emissions are mainly dominated by the mole ratio of ethanol to that of total fuel. To obtain chemical mechanistic informations relevant to the Ignition behavior, detailed chemical kinetic analysis was conducted. The simulated results also confirmed the retarding of the Ignition Timing by ethanol addition. In addition, it can be found from the simulation that HCHO, CO, and C2H5OH could not be oxidized completely and are maintained at high levels if the partial combustion or misfire occurs (for example, for leaner fuel/air mixture). © 2007 Published by Elsevier Inc. on behalf of The Combustion Institute.
-
experimental study on the auto Ignition and combustion characteristics in the homogeneous charge compression Ignition hcci combustion operation with ethanol n heptane blend fuels by port injection
Fuel, 2006Co-Authors: Yuchun Hou, Zhen HuangAbstract:Abstract This article investigates the auto-Ignition, combustion, and emission characteristics of homogeneous charge compression Ignition (HCCI) combustion engines fuelled with n -heptane and ethanol/ n -heptane blend fuels. The experiments were conducted on a single-cylinder HCCI engine using neat n -heptane, and 10%, 20%, 30%, 40%, and 50% ethanol/ n -heptane blend fuels (by volume) at a fixed engine speed of 1800 r/min. The results show that, with the introduction of ethanol in n -heptane, the maximum indicated mean effective pressure (IMEP) can be expanded from 3.38 bar of neat n -heptane to 5.1 bar, the indicated thermal efficiency can also be increased up to 50% at large engine loads, but the thermal efficiency deteriorated at light engine load. Due to the much higher octane number of ethanol, the cool-flame reaction delays, the initial temperature corresponding the cool-flame reaction increases, and the peak value of the low-temperature heat release decreases with the increase of ethanol addition in the blend fuels. Furthermore, the low-temperature heat release is indiscernible when the ethanol volume increases up to 50%. In the case of the neat n -heptane and 10% ethanol/ n -heptane blends, the combustion duration is very short due to the early Ignition Timing. For 20–50% ethanol/ n -heptane blend fuels, the Ignition Timing is gradually delayed to the top dead center (TDC) by the ethanol addition. As a result, the combustion duration prolongs obviously at the same engine load when compared to the neat n -heptane fuel. At overall stable operation ranges, the HC emissions for n -heptane and 10–30% ethanol/ n -heptane blends are very low, while HC emissions increase substantially for 40% and 50% ethanol/ n -heptane blends. CO emissions show another tendency compared to HC emissions. At the engine load of 1.5–2.5 bar, CO emissions are very high for all fuels. Beside this range, CO emissions decrease both for large load and light load. In terms of operation stability of HCCI combustion, for a constant energy input, n -heptane shows an excellent repeatability and light cycle-to-cycle variation, while the cycle-to-cycle variation of the maximum combustion pressure and its corresponding crank angle, and Ignition Timing deteriorated with the increase of ethanol addition.
B. Johansson - One of the best experts on this subject based on the ideXlab platform.
-
Hybrid modelling of homogeneous charge compression Ignition (HCCI) engine dynamics - A survey
International Journal of Control, 2007Co-Authors: J. Bengtsson, P. Strandh, Per Tunestal, R. Johansson, B. JohanssonAbstract:The Homogeneous charge compression Ignition (HCCI) principle holds promise to increase efficiency and to reduce emissions from internal combustion engines. As HCCI combustion lacks direct Ignition Timing control and auto-Ignition depends on the operating condition, control of auto-Ignition is necessary. Since auto-Ignition of a homogeneous mixture is very sensitive to operating conditions, a fast combustion phasing control is necessary for reliable operation. To this purpose, HCCI modelling and model-based control with experimental validation were studied. A six-cylinder heavy-duty HCCI engine was controlled on a cycle-to-cycle basis in real time using a variety of sensors, actuators and control structures for control of the HCCI combustion. Combustion phasing control based on ion current was compared to feedback control based on cylinder pressure. With several actuators for controlling HCCI engines suggested, two actuators were compared, dual fuel and variable valve actuation (VVA). Model-based control s...
-
Homogeneous Charge Compression Ignition with Water Injection
SAE Technical Paper Series, 1999Co-Authors: Magnus Christensen, B. JohanssonAbstract:The use of water injection in a homogeneous charge compression Ignition (HCCI) engine was experimentally investigated. The purpose of this study was to examine whether it is possible to control the Ignition Timing and slow down the rate of combustion with the use of water injection. The effects of different water flows, air/fuel ratios and inlet pressures were studied for three different fuels, iso-octane, ethanol and natural gas. It is possible to control the Ignition Timing in a narrow range with the use of water injection, but to the prize of an increase in the already high emissions of unburned hydrocarbons. The CO emission also increased. The NOx emissions, which are very low for HCCI, decreased even more when water injection was applied. The amount of water used was of the magnitude of the fuel flow. (Less)
Mingyue Wang - One of the best experts on this subject based on the ideXlab platform.
-
performance and emission characteristics of a turbocharged spark Ignition hydrogen enriched compressed natural gas engine under wide open throttle operating conditions
International Journal of Hydrogen Energy, 2010Co-Authors: Mingyue Wang, Jiao Deng, Long Jiang, Nashay Naeve, Renzhe Chen, Shuli ZhaoAbstract:This paper investigates the effect of various hydrogen ratios in HCNG (hydrogen-enriched compressed natural gas) fuels on performance and emission characteristics at wide open throttle operating conditions using a turbocharged spark-Ignition natural gas engine. The experimental data was taken at hydrogen fractions of 0%, 30% and 55% by volume and was conducted under different excess air ratio (λ) at MBT operating conditions. It is found that under various λ, the addition of hydrogen can significantly reduce CO, CH4 emissions and the NOx emission remain at an acceptable level when Ignition Timing is optimized. Using the same excess air ratio, as more hydrogen is added the power, exhaust temperatures and max cylinder pressure decrease slowly until the mixture’s lower heating value remains unchanged with the hydrogen enrichment, then they rise gradually. In addition, the early flame development period and the flame propagation duration are both shorter, and the indicated thermal efficiency and maximum heat release rate both increase with more hydrogen addition.
-
performance and emission characteristics of a turbocharged cng engine fueled by hydrogen enriched compressed natural gas with high hydrogen ratio
International Journal of Hydrogen Energy, 2010Co-Authors: Mingyue Wang, Jiao Deng, Long Jiang, Nashay Naeve, Renzhe Chen, Shuli ZhaoAbstract:Abstract This paper investigates the effect of high hydrogen volumetric ratio of 55% on performance and emission characteristics in a turbocharged lean burn natural gas engine. The experimental data was conducted under various operating conditions including different spark Timing, excess air ratio (lambda), and manifold pressure. It is found that the addition of hydrogen at a high volumetric ratio could significantly extend the lean burn limit, improve the engine lean burn ability, decrease burn duration, and yield higher thermal efficiency. The CO, CH 4 emissions were reduced and NO x emission could be kept an acceptable low level with high hydrogen content under lean burn conditions when Ignition Timing were optimized.
Jingping Liu - One of the best experts on this subject based on the ideXlab platform.
-
a review of controlling strategies of the Ignition Timing and combustion phase in homogeneous charge compression Ignition hcci engine
Fuel, 2021Co-Authors: Xiongbo Duan, Ming Chia Lai, Marcis Jansons, Genmiao Guo, Jingping LiuAbstract:Abstract Generally, the homogeneous charge compression Ignition (HCCI) engine presents superior fuel economy and ultra-low NOx and particle matter emissions compared with the traditional combustion engine. However, the HCCI engine is essentially decoupled from the spark plug and fuel injection. That means the HCCI engine has no direct control mechanism for the auto-Ignition Timing and subsequent combustion phase. Without effective strategies to control the auto-Ignition Timing on time according to the operating conditions, the HCCI engine will be limited in a small operation range due to the cold start problem, high pressure rate and combustion noise, and even knocking combustion at the high-load. Generally, the properties of physical–chemical kinetics of fuels, as well as the mixture temperature spatial and temporal changing histories in the cylinder, strongly determine the Ignition Timing and affect the combustion phase in HCCI engine. Some effective techniques and controlling strategies, such as fuel management, homogeneous charge preparation, exhaust gas recirculation, etc. are widely used in the HCCI engine. These techniques and controlling strategies are used solely or conjunctively with each other to control the compressed gas temperature, pressure and mixture distribution in the cylinder at the end of the compression stroke so that the charge mixture could be auto-ignited at the desired crank angle, and thereby obtaining optimal combustion phase and heat release rate on a wide operation range for the HCCI engine. Thus, this paper comprehensively reviews different effective techniques and controlling strategies used in the HCCI engine, and also summarizes in the tables.
-
the heat release analysis of bio butanol gasoline blends on a high speed si spark Ignition engine
Energy, 2013Co-Authors: Jingping Liu, Banglin Deng, Daming Zhang, Jing Yang, Renhua Feng, Xiaoqiang LiuAbstract:In this study, experiments were conducted on a single-cylinder high speed SI (spark Ignition) engine fueled with 30 and 35%vol butanol/gasoline blends and compared to the pure gasoline. This research is trying to find out the common principles about the influence on combustion heat release of SI engine for variables such as Ignition Timing, engine load, and butanol blend ratio in a wide engine speed range (3000–8500 rpm). The results showed that butanol provides higher knocking resistance by allowing advance the Ignition Timing in SI engines, leading to more efficient combustion. The laminar burning velocity of butanol is higher than that of gasoline, but that doesn't guarantee a faster burning speed in a real engine unless the combustion process is more reasonably organized, such as using the optimum Ignition Timing. In the overall trend, as the butanol blend ratio increasing, one can achieve a more efficient combustion process with using the optimum operating parameters. Obviously, the rate of heat release became slower and declined in peak value as the engine load decreases, accompanied by a shift of peak value to later for both pure gasoline and butanol/gasoline blends. In the aspect of fuel oxidation rate, the fuel–air ratio is the dominated factor rather than fuel type.
