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学者姓名：纪常伟
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摘要 ：
As a promising power system, hydrogen-fueled Wankel rotary engine with excellent power and emission characteristic have received attention increasingly, which makes it of great interest to investigate it. To make up for blanks, this work was conducted to experimentally investigate the effect of spark plug position on the combustion and emission characteristic of hydrogen-fueled Wankel rotary engine under 1500 r/min, 66 kPa manifold absolute pressure and 1.5 excess air ratio. The results indicate that compared to the trailing spark plug, the leading spark plug is more suitable to hydrogen-fueled Wankel rotary engines, which can realize a wider ignition range, higher maximum brake torque, lower cyclic variation and better nitric oxide emission. The maximum brake torque of adopting trailing spark plug is 31.2 N.m, which is only 87% of the maximum brake torque of 36.0 N.m with adopting leading spark plug. At the maximum brake torque ignition timing, adopting leading trailing spark plug achieves lower cyclic variation and slightly higher thermal load than adopting trailing spark plug. Besides, the optimum central heat-release point of both spark plug positions locate between 35 and 40 degrees CA after the top dead center, and that of leading spark plug is later 2 degrees CA than that of trailing spark plug. Moreover, both spark plug positions obtained 0 nitric oxide emission at maximum brake torque ignition timing, which means that emission will not be a problem to limit the selection of spark plug position under tested conditions.
关键词 ：
Combustion Combustion Emission Emission Hydrogen Hydrogen Spark plug position Spark plug position Wankel rotary engine Wankel rotary engine
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| GB/T 7714 | Yang, Jinxin , Meng, Hao , Ji, Changwei et al. Comparatively investigating the leading and trailing spark plug on the hydrogen rotary engine [J]. | FUEL , 2022 , 308 . |
| MLA | Yang, Jinxin et al. "Comparatively investigating the leading and trailing spark plug on the hydrogen rotary engine" . | FUEL 308 (2022) . |
| APA | Yang, Jinxin , Meng, Hao , Ji, Changwei , Wang, Shuofeng . Comparatively investigating the leading and trailing spark plug on the hydrogen rotary engine . | FUEL , 2022 , 308 . |
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摘要 ：
为了探究进气角度对转子机性能的影响,以复合进气转子机为研究对象,构建并验证了适用于转子机工作过程的CFD模型。通过数值模拟的方法,对不同端面进气角度下氢气/汽油双燃料转子机的缸内流场和燃烧过程进行了研究。结果表明,随着进气角度的增加,从端面进气口进入的混合气与气缸后端盖的撞击点不断向燃烧室前方移动,从周边进气口进入的气体在燃烧室后端形成滚流,缸内混合气的平均涡度变大;在上止点附近缸内会形成与转子运动方向一致的单向流;在点火时刻缸内混合气的流速随着进气角度的增加略有降低,导致火焰传播速度变慢,燃料放热速率降低;相比于进气角度为0°时,当进气角度增加为60°时峰值缸压上升了7.44%,但NOx的生...
关键词 ：
氢气 氢气 端面进气角度 端面进气角度 转子机 转子机 燃烧过程 燃烧过程 缸内流场 缸内流场
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| GB/T 7714 | 马泽东 , 纪常伟 , 史程 et al. 端面进气角度对掺氢转子机性能的影响 [J]. | 广西大学学报(自然科学版) , 2021 , 46 (02) : 373-383 . |
| MLA | 马泽东 et al. "端面进气角度对掺氢转子机性能的影响" . | 广西大学学报(自然科学版) 46 . 02 (2021) : 373-383 . |
| APA | 马泽东 , 纪常伟 , 史程 , 杨金鑫 , 李欣 , 刘建峰 . 端面进气角度对掺氢转子机性能的影响 . | 广西大学学报(自然科学版) , 2021 , 46 (02) , 373-383 . |
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摘要 ：
本发明提供了一种识别电动汽车锂离子电池高温状况及快速精确灭火装置，包括一个灭火剂箱，箱体上表面有内嵌有一个灭火剂入口和出口阀，可以添加灭火剂或者更换不同的灭火剂，并保证电池包上盖的平整性。箱体下表面有单向阀，单向阀的出口处填装有的感温绝缘填料在感知到导热丝传递的最高温度后，如果达到热失控的临界温度就会熔化，进而释放出灭火剂箱内的灭火剂对即将热失控的电池单体进行精准的降温或灭火，减小了灭火剂箱的体积，并通过热绝缘电池隔板阻止该热失控电池单体蔓延至其它电池单体。单向阀与感温绝缘填料之间的感温线路将热失控信号传递至电动车内部的火灾报警器，提醒驾乘人员及时撤离，无需加装火灾报警器，降低了成本。
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| GB/T 7714 | 纪常伟 , 张知足 , 汪硕峰 et al. 一种识别电动汽车锂离子电池高温状况及精准灭火装置 : CN202110185698.9[P]. | 2021-02-11 . |
| MLA | 纪常伟 et al. "一种识别电动汽车锂离子电池高温状况及精准灭火装置" : CN202110185698.9. | 2021-02-11 . |
| APA | 纪常伟 , 张知足 , 汪硕峰 , 王兵 , 戚朋飞 , 张守芹 et al. 一种识别电动汽车锂离子电池高温状况及精准灭火装置 : CN202110185698.9. | 2021-02-11 . |
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摘要 ：
To achieve more efficient and robust combustion, split direct-injected hydrogen as a new injection strategy for rotary engines was used to clarify the influences of various injection parameters, including hydrogen amount for each pulse, the dwell between pulses, and secondary injection pulse-width, on combustion performance and emissions formation by CFD modeling. The results of this investigation confirmed the benefit of split direct-injection as a useful means to govern mixture stratification which enabled the combustion more effective and rapid compared to single-injection mode. Enhanced combustion could be achieved by increasing the mass fraction of post-injection with an optimized dwell between injections. Further investigation on secondary injection pulse-width demonstrated that engine performance was substantially improved with a wider second injection pulse. From one side, as the secondary injection pulse-width was increased, the surrounding mixture distribution of the spark-plug location was richer, which was confirmed as a beneficial inhomogeneous circumstance of hydrogen to accelerate the burning rate. From another side, strong tumble level and turbulence intensity were of significant importance for facilitating the combustion process and getting optimal thermal efficiency. For emissions formation, split direct-injected hydrogen made a near-zero HC and CO emissions at the price of a comparable increase of NOx emissions. © 2020 Elsevier Ltd
关键词 ：
Combustion Combustion Direct injection Direct injection Hydrogen Hydrogen Internal combustion engines Internal combustion engines Mixtures Mixtures Rotary engines Rotary engines
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| GB/T 7714 | Shi, Cheng , Ji, Changwei , Ge, Yunshan et al. Effects of split direct-injected hydrogen strategies on combustion and emissions performance of a small-scale rotary engine [J]. | Energy , 2021 , 215 . |
| MLA | Shi, Cheng et al. "Effects of split direct-injected hydrogen strategies on combustion and emissions performance of a small-scale rotary engine" . | Energy 215 (2021) . |
| APA | Shi, Cheng , Ji, Changwei , Ge, Yunshan , Wang, Shuofeng , Yang, Jinxin , Wang, Huaiyu . Effects of split direct-injected hydrogen strategies on combustion and emissions performance of a small-scale rotary engine . | Energy , 2021 , 215 . |
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摘要 ：
The purpose of current research was to implement an intelligent regression model and multi-objective optimization of performance, combustion and emissions characteristics for a hydrogen-enriched gasoline rotary engine. The brake thermal efficiency (BTE), fuel energy flow rate (E-f), nitrogen oxides (NOX), carbon monoxide (CO) and hydrocarbon (HC) were predicted by intelligent regression model with hydrogen volume fraction (alpha(H2)), excess air ratio (lambda) and ignition timing (IT) as independent variables. The intelligent regression models were based on support vector machine (SVM) and optimized by the genetic algorithm (GA) to obtain the optimal parameters of the regression model. The data for training the SVM model were derived from the experimental results of a hydrogen-enriched rotary engine, in which the speed was kept constant at 4500 r/min, the absolute manifold pressure remained at 35 KPa, the variation of alpha(H2), lambda and IT were 0-6%, 1-1.3 and 24-42 degrees CA before top dead center (bTDC), respectively. After optimized by GA, the coefficient of determination of BTE, E-f, NOX, CO and HC between the SVM model and the corresponding data were greater than 0.98, and the mean absolute percentage error were <1%. The performance, combustion, and emissions characteristics including BTE, E-f, NOX, CO and HC were considered for multi-objective optimization to obtain higher performance and lower emissions, and were solved using the non-dominated sorting genetic algorithm II. For this study, when the Pareto-optimal solutions were obtained, the optimal operating parameters were further obtained by limiting the performance and emissions parameters with the alpha(H2) of 5.06%, lambda of 1.09%, and IT of 34.27 degrees CA bTDC.
关键词 ：
Hydrogen enrichment Hydrogen enrichment Multi-objective optimization Multi-objective optimization Operating parameters Operating parameters Support vector machine Support vector machine Wankel rotary engine Wankel rotary engine
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| GB/T 7714 | Ji, Changwei , Wang, Huaiyu , Shi, Cheng et al. Multi-objective optimization of operating parameters for a gasoline Wankel rotary engine by hydrogen enrichment [J]. | ENERGY CONVERSION AND MANAGEMENT , 2021 , 229 . |
| MLA | Ji, Changwei et al. "Multi-objective optimization of operating parameters for a gasoline Wankel rotary engine by hydrogen enrichment" . | ENERGY CONVERSION AND MANAGEMENT 229 (2021) . |
| APA | Ji, Changwei , Wang, Huaiyu , Shi, Cheng , Wang, Shuofeng , Yang, Jinxin . Multi-objective optimization of operating parameters for a gasoline Wankel rotary engine by hydrogen enrichment . | ENERGY CONVERSION AND MANAGEMENT , 2021 , 229 . |
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摘要 ：
A computational fluid dynamics model was established and validated to numerically investigate the effects of different injection positions and injection angles on the mixture formation and combustion process in a gasoline direct injection rotary engine. The results show that as the injection position approaches the top dead center and the increasing injection angle, the rich zone of fuel changes from the rear to the front of the combustion chamber. The local equivalence ratio near the two spark plugs shows an increasing trend with the injection position upward and the increasing injection angle. Compared with the lower and middle injection positions, the upper injection positions can make fuel more concentrated near the leading spark plug and the trailing spark plug at ignition timing. The injection strategies corresponding to the upper injection position are conducive to complete combustion, in which the mass fraction of fuel burned all beyond 99%. Besides, with the increasing injection angle, the oil film formation position changes from the rotor recess to the middle cylinder block, which further affects the mixture formation and combustion process. Especially, the highest peak pressure is obtained at 0 degrees injection angle corresponding to the upper injection position and is 12.39% higher than the in-cylinder peak pressure of intake port injection.
关键词 ：
Combustion process Combustion process Direct injection Direct injection Gasoline rotary engine Gasoline rotary engine Injection angle Injection angle Injection position Injection position Mixture formation Mixture formation
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| GB/T 7714 | Ji, Changwei , Chang, Ke , Wang, Shuofeng et al. Effect of injection strategy on the mixture formation and combustion process in a gasoline direct injection rotary engine [J]. | FUEL , 2021 , 304 . |
| MLA | Ji, Changwei et al. "Effect of injection strategy on the mixture formation and combustion process in a gasoline direct injection rotary engine" . | FUEL 304 (2021) . |
| APA | Ji, Changwei , Chang, Ke , Wang, Shuofeng , Yang, Jinxin , Wang, Du , Meng, Hao et al. Effect of injection strategy on the mixture formation and combustion process in a gasoline direct injection rotary engine . | FUEL , 2021 , 304 . |
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摘要 ：
The development of alternative fuels is important in the fight against climate change. Both hydrogen and ammonia are renewable energy sources and are carbon-free combustible fuels. In a recent experimental study, the performance and emission characteristics of a spark-ignition engine burning a premixed hydrogen/ammonia/air mixture were evaluated. The manifold absolute pressure was adjusted to 61 kPa and the engine speed was stabilized at 1300 rpm. The difference between a mixture with a 2.2% volume fraction of ammonia and a pure hydrogen fuel was analyzed in comparison. Specifically, the addition of ammonia increased the ignition delay and flame development periods and reduced the rate of in-cylinder pressure rise. In conjunction with the ignition timing strategy, the addition of ammonia did not affect the engine performance. Nitrogen oxides emissions are increased due to the addition of ammonia. The experimental results suggest that ammonia can be used as a combustion inhibitor, which provides a new reference for the development of hydrogen-fuelled engines. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
关键词 ：
Ammonia/hydrogen dual-fuel Ammonia/hydrogen dual-fuel Combustion Combustion Dual-injection Dual-injection Emissions Emissions Ignition timing Ignition timing
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| GB/T 7714 | Ji, Changwei , Xin, Gu , Wang, Shuofeng et al. Effect of ammonia addition on combustion and emissions performance of a hydrogen engine at part load and stoichiometric conditions [J]. | INTERNATIONAL JOURNAL OF HYDROGEN ENERGY , 2021 , 46 (80) : 40143-40153 . |
| MLA | Ji, Changwei et al. "Effect of ammonia addition on combustion and emissions performance of a hydrogen engine at part load and stoichiometric conditions" . | INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 46 . 80 (2021) : 40143-40153 . |
| APA | Ji, Changwei , Xin, Gu , Wang, Shuofeng , Cong, Xiaoyu , Meng, Hao , Chang, Ke et al. Effect of ammonia addition on combustion and emissions performance of a hydrogen engine at part load and stoichiometric conditions . | INTERNATIONAL JOURNAL OF HYDROGEN ENERGY , 2021 , 46 (80) , 40143-40153 . |
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摘要 ：
Cold start is one of the urgent problems to be solved in the process of commercialization for the polymer electrolyte membrane fuel cell (PEMFC). In this study, cold start processes under constant power start-up are simulated with a three-dimensional transient model. Evolutions of voltage and current density under higher and lower current density under this mode are elucidated. The water accumulation location in the PEMFC is analyzed and effects of important parameters on the process of cold start are quantified under constant power start-up mode. The results show that the current density first increases and then decreases when the PEMFC starts from a higher current density under constant power start-up mode, while it is reversed when the PEMFC starts from a lower current density. Ice first appears in the area near the membrane under the channel and the hottest area in the cell also appears below the channel. At the lower current density, the distribution of water in ionomer is more uniform. Under two different starting current densities, the changing trends of the conductivity of the membrane and the anode catalyst layer are different. The activational heat is the largest heat source in the cold start process under constant power start-up mode and the utilization of ionomer water storage is higher when the PEMFC starts from a lower current density. The temperature of the inlet gas is most sensitive to the cold start process at lower current density. And initial content of membrane water and membrane thickness have important impacts on the cold start performance when PEMFC starts from a higher current density due to the redistribution of potential.
关键词 ：
cold start cold start constant power constant power PEMFC PEMFC start-up mode start-up mode
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| GB/T 7714 | Niu, Huipeng , Ji, Changwei , Wang, Shuofeng et al. Analysis of the cold start behavior of a polymer electrolyte membrane fuel cell in constant power start-up mode [J]. | INTERNATIONAL JOURNAL OF ENERGY RESEARCH , 2021 , 45 (13) : 19245-19264 . |
| MLA | Niu, Huipeng et al. "Analysis of the cold start behavior of a polymer electrolyte membrane fuel cell in constant power start-up mode" . | INTERNATIONAL JOURNAL OF ENERGY RESEARCH 45 . 13 (2021) : 19245-19264 . |
| APA | Niu, Huipeng , Ji, Changwei , Wang, Shuofeng , Shi, Mengyuan , Zhang, Hanlin , Liang, Chen . Analysis of the cold start behavior of a polymer electrolyte membrane fuel cell in constant power start-up mode . | INTERNATIONAL JOURNAL OF ENERGY RESEARCH , 2021 , 45 (13) , 19245-19264 . |
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摘要 ：
Spark-ignition combustion mode could be used to widen the operation range of homogeneous charge compression ignition combustion mode on a hydrogen-dimethyl ether (DME) engine. To improve power output and reduce nitrogen oxides emissions, this study investigated the combustion and emissions properties of a hydrogen-DME spark-ignition engine under various DME fractions (alpha(DME)). The result showed that flame development and propagation periods were extended after DME blended. The increases of both periods were 1.7 and 2.0 degrees CA when alpha(DME) various from 1.4% to 3.0%, respectively. However, when alpha(DME) increased to 3.4%, flame propagation period had a 1.7 degrees CA reduction because of the spontaneous high-temperature oxidation of a few end unburned mixtures. Blending DME could improve power output of the neat hydrogen engine. The maximum improvement of indicated mean effective pressure could achieve 18.3%, after DME addition. Because of the weakened flame kernel and flame propagation process, when alpha(DME) lower than 3.0%, blending DME increased cyclic variation yet the variations were in 0.13%. Nitrogen oxides emissions could be reduced significantly, when DME was added into the neat hydrogen engine. The maximum reduction could achieve 49.9%, based on neat hydrogen fuel-supply mode. Hydrocarbon and carbon monoxide emissions were increased after DME addition. When alpha(DME) increased from 1.4% to 3.4%, the enhancement of hydrocarbon emissions was about two-third lower than that of carbon monoxide emission.
关键词 ：
Combustion Combustion Dimethyl ether Dimethyl ether Emissions Emissions Hydrogen Hydrogen Spark ignition Spark ignition
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| GB/T 7714 | Cong, Xiaoyu , Ji, Changwei , Wang, Shuofeng . Investigation into engine performance of a hydrogen-dimethyl ether spark-ignition engine under various dimethyl ether fractions [J]. | FUEL , 2021 , 306 . |
| MLA | Cong, Xiaoyu et al. "Investigation into engine performance of a hydrogen-dimethyl ether spark-ignition engine under various dimethyl ether fractions" . | FUEL 306 (2021) . |
| APA | Cong, Xiaoyu , Ji, Changwei , Wang, Shuofeng . Investigation into engine performance of a hydrogen-dimethyl ether spark-ignition engine under various dimethyl ether fractions . | FUEL , 2021 , 306 . |
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摘要 ：
This work aims to improve the idle performance of the n-butanol rotary engine by blending hydrogen and reducing idle speed. Hydrogen volume percentage (beta(H2)) changes from 0 to 7.94% and the idle speed decreases from 2600 to 2400 rpm. The test results show that the engine can achieve better stability and economy due to the coupling effect of mixing hydrogen and reducing the idling. The total fuel flow rate reduces from 24.57 MJ/h at 2600 rpm when pure n-butanol is fueled to 19.35 MJ/h at 2400 rpm when beta(H2) equals to 7.94%. The period of flame development and propagation are observably decreased by blending hydrogen even if reducing idle speed has a few negative effects. Hydrogen enrichment is an effective way to reduce the emissions of CO and HC. Besides, the negative effects of reducing idle speed on HC and CO emissions are decreased to a negligible level when beta(H2) passes about 7%. Besides, NOx emission is maintained at an extremely low value in the testing range. Also, enrichment hydrogen can compensate for the negative effects on combustion and emissions of reducing idle speed.
关键词 ：
Combustion Combustion Emissions Emissions Hydrogen enrichment Hydrogen enrichment Idle speed reduction Idle speed reduction N-butanol N-butanol Wankel rotary engine Wankel rotary engine
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| GB/T 7714 | Meng, Hao , Ji, Changwei , Wang, Shuofeng et al. Optimizing the idle performance of an n-butanol fueled Wankel rotary engine by hydrogen addition [J]. | FUEL , 2021 , 288 . |
| MLA | Meng, Hao et al. "Optimizing the idle performance of an n-butanol fueled Wankel rotary engine by hydrogen addition" . | FUEL 288 (2021) . |
| APA | Meng, Hao , Ji, Changwei , Wang, Shuofeng , Wang, Du , Yang, Jinxin . Optimizing the idle performance of an n-butanol fueled Wankel rotary engine by hydrogen addition . | FUEL , 2021 , 288 . |
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