The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Xiaoyu Cong - One of the best experts on this subject based on the ideXlab platform.
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Idle performance of a hydrogen Rotary Engine at different excess air ratios
International Journal of Hydrogen Energy, 2018Co-Authors: Shuofeng Wang, Jinxin Yang, Lei Shi, Xiaoyu CongAbstract:Abstract Rotary Engine has flat chamber and longs for fuel with high flame speed and small quenching distance. Hydrogen has many excellent characteristics that are suitable for the Rotary Engine. In this paper, the performance of a Rotary Engine fueled with pure hydrogen at different excess air ratios was experimentally investigated. The investigation was carried out on a single-rotor hydrogen-fueled Rotary Engine equipped with port fuel injection system. An online electronic control module was used to govern the hydrogen injection duration and excess air ratio. In this study, the Engine was operating at the idle speed of 3000 rpm and different excess air ratios varied from 0.993 to 1.283. The test results demonstrated that the fuel energy flow rate of the hydrogen Rotary Engine and Engine stability were reduced with the increase of excess air ratio. When the excess air ratio increased from 0.993 to 1.283, the hydrogen energy flow rate was decreased from 14.91 to 11.55 MJ/h. Both the flame development and propagation periods were increased with excess air ratio. CO emission was negligible, but HC, CO2 and NOx emissions were still detected due to the evaporation and possible burning of the lubrication-used gasoline, and oxidation reaction of nitrogen of the intake air.
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Improving the combustion performance of a gasoline Rotary Engine by hydrogen enrichment at various conditions
International Journal of Hydrogen Energy, 2018Co-Authors: Shuofeng Wang, Xiaoyu Cong, Lei ShiAbstract:Abstract The combustion process within the cylinder directly influences the thermal efficiency and performance of the Engines. As for the Rotary Engine, the long-narrow combustion chamber prevents the mixture from fully burning, which worsens the performance of the Rotary Engine. As a fuel with excellent properties, hydrogen can improve the combustion of the original Engine. In this paper, improvements in combustion of a gasoline Rotary Engine by hydrogen supplement under different operating conditions were experimentally investigated. The experiment was conducted on a modified hydrogen-gasoline dual-fuel Rotary Engine equipped with an electronically-controlled fuel injection system. An electronic control module was specially made to command the fuel injection, excess air ratio and hydrogen volumetric fraction. Integral heat release fraction (IHRF) was employed to evaluate the combustion of the tested Engine. The tested Engine was first run at the idle speed of 2400 rpm and then operated at 4500 rpm to investigate the combustion of the hydrogen-blended gasoline Rotary Engine under different hydrogen volume fractions, excess air ratios and spark timings. The testing results demonstrated that the combustion of the gasoline Rotary Engine were all improved when the hydrogen was blended into the chamber under all tested conditions.
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Enhancing idle performance of an n-butanol Rotary Engine by hydrogen enrichment
International Journal of Hydrogen Energy, 2018Co-Authors: Shuofeng Wang, Xiaoyu Cong, Lei ShiAbstract:Abstract Rotary Engine generally sustains poor fuel economy and emissions performance at idle condition. Hydrogen has excellent physicochemical properties that can serve as an enhancer to improve the performance of the original Engine. In this paper, a modified Rotary Engine equipped with dual fuel (hydrogen and n-butanol) port injection system and electronic ignition module was developed to explore the influence of hydrogen supplement on enhancing the idle performance of n-butanol Rotary Engine. In this study, the Engine was run at the idle and stoichiometric with the original spark timing. Hydrogen volume percentage in the total intake was gradually increased from 0% to 7.9% by adjusting the fuel flow rate of n-butanol. The experimental results indicated that the Engine instability and fuel energy flow rate were both reduced by enlarging the hydrogen supplying level. Combustion periods were shortened thanks to the enrichment of hydrogen. The peak chamber temperature was heightened as hydrogen fraction increased due to the improved combustion. HC and CO emissions were severally reduced by 50.4% and 85.8% when the hydrogen volume percentage was raised from 0% to 7.9%. However, NOx emissions were mildly increased because of the raised chamber temperature by increasing hydrogen fraction.
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Research on performance of a hydrogen/n-butanol Rotary Engine at idling and varied excess air ratios
Energy Conversion and Management, 2018Co-Authors: Shuofeng Wang, Xiaoyu Cong, Lei ShiAbstract:Abstract The structure chamber of Rotary Engine is irregular compared with traditional reciprocating Engines. Pure n -butanol Rotary Engine normally encounters partial burning and even misfire at idling and lean conditions. Comparatively, hydrogen supplement can ameliorate performance of original Engine. In this paper, experimentation of a Rotary Engine fueled with pure n -butanol and hydrogen/ n -butanol blends at idling and different excess air ratios was conducted. Experimental results manifested that hydrogen addition effectively decreased the Engine instability and fuel energy flow rate. To be specific, fuel energy flow rate at the excess air ratio of 1.05 was reduced from 23.63 MJ/h to 21.26 MJ/h when 3% hydrogen was added. Combustion duration was lowered after introducing hydrogen. Maximum chamber temperature was heightened after hydrogen addition. HC and CO emissions were reduced when 3% hydrogen was added. NOx emissions were reduced when the mixture was leaned out.
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Improving the lean performance of an n-butanol Rotary Engine by hydrogen enrichment
Energy Conversion and Management, 2018Co-Authors: Shuofeng Wang, Lei Shi, Xiaoyu Cong, Jinxin YangAbstract:Abstract The present paper introduced an experiment survey focusing on exploring the impact of hydrogen enrichment on improving the lean-burn performance of an n-butanol Rotary Engine. During the test, the Engine speed and intake pressure were roughly set at 4000 rpm and 35 kPa, respectively. A constant spark advance of 45 °CA was adopted through the test. Hydrogen volumetric fraction of the total intake was severally kept at 0% and 3%. The testing results manifested that the brake thermal efficiency and peak chamber temperature were heightened with hydrogen addition. Besides, the ignition delay and rapid combustion duration were both reduced with the hydrogen additive. Engine running stability gained an improvement by hydrogen supplement. Moreover, HC and CO emissions from the original n-butanol Rotary Engine were reduced after hydrogen adding. NOx emissions were increased with hydrogen enrichment while reduced with the increase of excess air ratio. This indicated that NOx emissions from both the n-butanol and hydrogen-blended n-butanol Rotary Engines could be reduced by lean combustion strategies.
Shuofeng Wang - One of the best experts on this subject based on the ideXlab platform.
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Investigation of the gas injection rate shape on combustion, knock and emissions behavior of a Rotary Engine with hydrogen direct-injection enrichment
International Journal of Hydrogen Energy, 2021Co-Authors: Huaiyu Wang, Cheng Shi, Shuofeng Wang, Jinxin YangAbstract:Abstract The application of hydrogen direct-injection enrichment improves the performance of gasoline Wankel Rotary Engine, and the hydrogen injection strategy has a significant impact on combustion, knock, and emissions. The Z160F Wankel Rotary Engine was used as the investigated compact Engine, and the simulation model was developed using CONVERGE software. The combustion, knock and emissions characteristics of the Engine were studied with the different mass flow of hydrogen injection, i.e., the trapezoid, wedge, slope, triangle and rectangle type of gas injection rate shape. In the numerical simulations, the in-cylinder pressure oscillations were monitored using monitoring points, and the knock index (KI) was used as an evaluation indicator. The study revealed that the gas injection rate shape significantly affected the mixture of hydrogen and air, thus impacting combustion, knock and emissions. When the injection rate shape was rectangle, the flame speed was faster, the peak pressure in the cylinder was higher, and the corresponding crank angle was earlier, which led to higher pressure oscillations in the cylinder and larger KI. Based on the rectangle injection rate shape, the KI decreased by 75.81%, 33.47%, 26.46% and 76.58% for trapezoid, wedge, slope, and triangle, respectively, and the indicated mean effective pressure increased by 15.68%, 5.07%, 0.56% and 14.98%, respectively. Due to the small difference in maximum temperature, which resulted in very little variation in nitrogen oxides for each injection rate shape, the total hydrocarbon emissions of the trapezoid and triangle injection rate shape was high due to the delayed combustion phase. This paper provides a solution for direct hydrogen injection to improve the combustion, knock and emissions behavior of the Rotary Engine.
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Potential improvement in combustion behavior of a downsized Rotary Engine by intake oxygen enrichment
Energy Conversion and Management, 2020Co-Authors: Shi Cheng, Shuofeng Wang, Jinxin Yang, Ma Zedong, Meng HaoAbstract:Abstract The attractiveness of oxygen-enriched combustion advantages are making a comeback in the implementation of the Rotary Engine concept. In this connection, a numerical investigation on influences of intake oxygen enrichment combined with excess air ratio on combustion behavior of the Rotary Engine needs to be clarified. A three-dimensional computational fluid dynamics simulations coupling with chemical kinetic mechanisms was performed in this study, and the numerical results had been validated with existing experimental data. The species evolution, combustion characteristics, and pollutant formation were monitored to assess the oxygen-enriched combustion of the Rotary Engine. Results showed that there was a significant influence of intake oxygen enrichment for improving flame development and burned volume due to the reasonable species concentration and intense turbulence intensity. Increasing oxygen enrichment led to the enhanced peak pressure and advanced corresponding position, resulted in a rapid combustion period for improving heat-release efficiency and combustion efficiency, meanwhile made a higher indicated mean effective pressure at the price of a smaller increment of nitrogen oxide formation. The substantial reductions of carbon monoxide, unburned hydrocarbon, and soot were recorded, which is attributed to the higher-oxygen mixture with suitable lean operations. Considering combustion characteristics and emissions performance, the operation of intake oxygen volume of 30% accompanying the excess air ratio of 1.1 is the best choice for the Engine used in the current study.
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numerical investigation on the mixture formation and combustion processes of a gasoline Rotary Engine with direct injected hydrogen enrichment
Applied Energy, 2018Co-Authors: Jinxin Yang, Shuofeng Wang, Du Wang, Boya ZhangAbstract:Abstract The present study established a computational fluid dynamics model and numerically investigated the mixture formation and combustion processes of a gasoline Rotary Engine enriched by the direct injected hydrogen at three injection positions. It is found that the special flow field inside Rotary Engine combustion chamber has strong interactions with the hydrogen jet-flow, and the hydrogen distribution could further influence the charge combustion. At the end stage of compression stroke, the mainstream field whose direction same to rotor movement is formed, and a vortex with high vorticity existed in the front of combustion chamber. With the influences of mainstream field and vortex, the hydrogen almost fills half of combustion chamber and properly rich hydrogen region distribution is obtained near the spark plug with the injection position close to the spark plug. In addition, proper equivalence ratio distribution could enhance the flame propagation and mixtures combustion completeness in rear region of combustion chamber. Compared with injection position far away from the spark plug, the peak in-cylinder pressure of the injection position close to the spark plug increases by 18.3%, and carbon monoxide emission is decreased obviously, but nitrogen monoxide emission increases due to higher in-cylinder temperature.
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Idle performance of a hydrogen Rotary Engine at different excess air ratios
International Journal of Hydrogen Energy, 2018Co-Authors: Shuofeng Wang, Jinxin Yang, Lei Shi, Xiaoyu CongAbstract:Abstract Rotary Engine has flat chamber and longs for fuel with high flame speed and small quenching distance. Hydrogen has many excellent characteristics that are suitable for the Rotary Engine. In this paper, the performance of a Rotary Engine fueled with pure hydrogen at different excess air ratios was experimentally investigated. The investigation was carried out on a single-rotor hydrogen-fueled Rotary Engine equipped with port fuel injection system. An online electronic control module was used to govern the hydrogen injection duration and excess air ratio. In this study, the Engine was operating at the idle speed of 3000 rpm and different excess air ratios varied from 0.993 to 1.283. The test results demonstrated that the fuel energy flow rate of the hydrogen Rotary Engine and Engine stability were reduced with the increase of excess air ratio. When the excess air ratio increased from 0.993 to 1.283, the hydrogen energy flow rate was decreased from 14.91 to 11.55 MJ/h. Both the flame development and propagation periods were increased with excess air ratio. CO emission was negligible, but HC, CO2 and NOx emissions were still detected due to the evaporation and possible burning of the lubrication-used gasoline, and oxidation reaction of nitrogen of the intake air.
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Improving the combustion performance of a gasoline Rotary Engine by hydrogen enrichment at various conditions
International Journal of Hydrogen Energy, 2018Co-Authors: Shuofeng Wang, Xiaoyu Cong, Lei ShiAbstract:Abstract The combustion process within the cylinder directly influences the thermal efficiency and performance of the Engines. As for the Rotary Engine, the long-narrow combustion chamber prevents the mixture from fully burning, which worsens the performance of the Rotary Engine. As a fuel with excellent properties, hydrogen can improve the combustion of the original Engine. In this paper, improvements in combustion of a gasoline Rotary Engine by hydrogen supplement under different operating conditions were experimentally investigated. The experiment was conducted on a modified hydrogen-gasoline dual-fuel Rotary Engine equipped with an electronically-controlled fuel injection system. An electronic control module was specially made to command the fuel injection, excess air ratio and hydrogen volumetric fraction. Integral heat release fraction (IHRF) was employed to evaluate the combustion of the tested Engine. The tested Engine was first run at the idle speed of 2400 rpm and then operated at 4500 rpm to investigate the combustion of the hydrogen-blended gasoline Rotary Engine under different hydrogen volume fractions, excess air ratios and spark timings. The testing results demonstrated that the combustion of the gasoline Rotary Engine were all improved when the hydrogen was blended into the chamber under all tested conditions.
Jinxin Yang - One of the best experts on this subject based on the ideXlab platform.
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Investigation of the gas injection rate shape on combustion, knock and emissions behavior of a Rotary Engine with hydrogen direct-injection enrichment
International Journal of Hydrogen Energy, 2021Co-Authors: Huaiyu Wang, Cheng Shi, Shuofeng Wang, Jinxin YangAbstract:Abstract The application of hydrogen direct-injection enrichment improves the performance of gasoline Wankel Rotary Engine, and the hydrogen injection strategy has a significant impact on combustion, knock, and emissions. The Z160F Wankel Rotary Engine was used as the investigated compact Engine, and the simulation model was developed using CONVERGE software. The combustion, knock and emissions characteristics of the Engine were studied with the different mass flow of hydrogen injection, i.e., the trapezoid, wedge, slope, triangle and rectangle type of gas injection rate shape. In the numerical simulations, the in-cylinder pressure oscillations were monitored using monitoring points, and the knock index (KI) was used as an evaluation indicator. The study revealed that the gas injection rate shape significantly affected the mixture of hydrogen and air, thus impacting combustion, knock and emissions. When the injection rate shape was rectangle, the flame speed was faster, the peak pressure in the cylinder was higher, and the corresponding crank angle was earlier, which led to higher pressure oscillations in the cylinder and larger KI. Based on the rectangle injection rate shape, the KI decreased by 75.81%, 33.47%, 26.46% and 76.58% for trapezoid, wedge, slope, and triangle, respectively, and the indicated mean effective pressure increased by 15.68%, 5.07%, 0.56% and 14.98%, respectively. Due to the small difference in maximum temperature, which resulted in very little variation in nitrogen oxides for each injection rate shape, the total hydrocarbon emissions of the trapezoid and triangle injection rate shape was high due to the delayed combustion phase. This paper provides a solution for direct hydrogen injection to improve the combustion, knock and emissions behavior of the Rotary Engine.
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Potential improvement in combustion behavior of a downsized Rotary Engine by intake oxygen enrichment
Energy Conversion and Management, 2020Co-Authors: Shi Cheng, Shuofeng Wang, Jinxin Yang, Ma Zedong, Meng HaoAbstract:Abstract The attractiveness of oxygen-enriched combustion advantages are making a comeback in the implementation of the Rotary Engine concept. In this connection, a numerical investigation on influences of intake oxygen enrichment combined with excess air ratio on combustion behavior of the Rotary Engine needs to be clarified. A three-dimensional computational fluid dynamics simulations coupling with chemical kinetic mechanisms was performed in this study, and the numerical results had been validated with existing experimental data. The species evolution, combustion characteristics, and pollutant formation were monitored to assess the oxygen-enriched combustion of the Rotary Engine. Results showed that there was a significant influence of intake oxygen enrichment for improving flame development and burned volume due to the reasonable species concentration and intense turbulence intensity. Increasing oxygen enrichment led to the enhanced peak pressure and advanced corresponding position, resulted in a rapid combustion period for improving heat-release efficiency and combustion efficiency, meanwhile made a higher indicated mean effective pressure at the price of a smaller increment of nitrogen oxide formation. The substantial reductions of carbon monoxide, unburned hydrocarbon, and soot were recorded, which is attributed to the higher-oxygen mixture with suitable lean operations. Considering combustion characteristics and emissions performance, the operation of intake oxygen volume of 30% accompanying the excess air ratio of 1.1 is the best choice for the Engine used in the current study.
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numerical investigation on the mixture formation and combustion processes of a gasoline Rotary Engine with direct injected hydrogen enrichment
Applied Energy, 2018Co-Authors: Jinxin Yang, Shuofeng Wang, Du Wang, Boya ZhangAbstract:Abstract The present study established a computational fluid dynamics model and numerically investigated the mixture formation and combustion processes of a gasoline Rotary Engine enriched by the direct injected hydrogen at three injection positions. It is found that the special flow field inside Rotary Engine combustion chamber has strong interactions with the hydrogen jet-flow, and the hydrogen distribution could further influence the charge combustion. At the end stage of compression stroke, the mainstream field whose direction same to rotor movement is formed, and a vortex with high vorticity existed in the front of combustion chamber. With the influences of mainstream field and vortex, the hydrogen almost fills half of combustion chamber and properly rich hydrogen region distribution is obtained near the spark plug with the injection position close to the spark plug. In addition, proper equivalence ratio distribution could enhance the flame propagation and mixtures combustion completeness in rear region of combustion chamber. Compared with injection position far away from the spark plug, the peak in-cylinder pressure of the injection position close to the spark plug increases by 18.3%, and carbon monoxide emission is decreased obviously, but nitrogen monoxide emission increases due to higher in-cylinder temperature.
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Idle performance of a hydrogen Rotary Engine at different excess air ratios
International Journal of Hydrogen Energy, 2018Co-Authors: Shuofeng Wang, Jinxin Yang, Lei Shi, Xiaoyu CongAbstract:Abstract Rotary Engine has flat chamber and longs for fuel with high flame speed and small quenching distance. Hydrogen has many excellent characteristics that are suitable for the Rotary Engine. In this paper, the performance of a Rotary Engine fueled with pure hydrogen at different excess air ratios was experimentally investigated. The investigation was carried out on a single-rotor hydrogen-fueled Rotary Engine equipped with port fuel injection system. An online electronic control module was used to govern the hydrogen injection duration and excess air ratio. In this study, the Engine was operating at the idle speed of 3000 rpm and different excess air ratios varied from 0.993 to 1.283. The test results demonstrated that the fuel energy flow rate of the hydrogen Rotary Engine and Engine stability were reduced with the increase of excess air ratio. When the excess air ratio increased from 0.993 to 1.283, the hydrogen energy flow rate was decreased from 14.91 to 11.55 MJ/h. Both the flame development and propagation periods were increased with excess air ratio. CO emission was negligible, but HC, CO2 and NOx emissions were still detected due to the evaporation and possible burning of the lubrication-used gasoline, and oxidation reaction of nitrogen of the intake air.
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Improving the lean performance of an n-butanol Rotary Engine by hydrogen enrichment
Energy Conversion and Management, 2018Co-Authors: Shuofeng Wang, Lei Shi, Xiaoyu Cong, Jinxin YangAbstract:Abstract The present paper introduced an experiment survey focusing on exploring the impact of hydrogen enrichment on improving the lean-burn performance of an n-butanol Rotary Engine. During the test, the Engine speed and intake pressure were roughly set at 4000 rpm and 35 kPa, respectively. A constant spark advance of 45 °CA was adopted through the test. Hydrogen volumetric fraction of the total intake was severally kept at 0% and 3%. The testing results manifested that the brake thermal efficiency and peak chamber temperature were heightened with hydrogen addition. Besides, the ignition delay and rapid combustion duration were both reduced with the hydrogen additive. Engine running stability gained an improvement by hydrogen supplement. Moreover, HC and CO emissions from the original n-butanol Rotary Engine were reduced after hydrogen adding. NOx emissions were increased with hydrogen enrichment while reduced with the increase of excess air ratio. This indicated that NOx emissions from both the n-butanol and hydrogen-blended n-butanol Rotary Engines could be reduced by lean combustion strategies.
Lei Shi - One of the best experts on this subject based on the ideXlab platform.
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Idle performance of a hydrogen Rotary Engine at different excess air ratios
International Journal of Hydrogen Energy, 2018Co-Authors: Shuofeng Wang, Jinxin Yang, Lei Shi, Xiaoyu CongAbstract:Abstract Rotary Engine has flat chamber and longs for fuel with high flame speed and small quenching distance. Hydrogen has many excellent characteristics that are suitable for the Rotary Engine. In this paper, the performance of a Rotary Engine fueled with pure hydrogen at different excess air ratios was experimentally investigated. The investigation was carried out on a single-rotor hydrogen-fueled Rotary Engine equipped with port fuel injection system. An online electronic control module was used to govern the hydrogen injection duration and excess air ratio. In this study, the Engine was operating at the idle speed of 3000 rpm and different excess air ratios varied from 0.993 to 1.283. The test results demonstrated that the fuel energy flow rate of the hydrogen Rotary Engine and Engine stability were reduced with the increase of excess air ratio. When the excess air ratio increased from 0.993 to 1.283, the hydrogen energy flow rate was decreased from 14.91 to 11.55 MJ/h. Both the flame development and propagation periods were increased with excess air ratio. CO emission was negligible, but HC, CO2 and NOx emissions were still detected due to the evaporation and possible burning of the lubrication-used gasoline, and oxidation reaction of nitrogen of the intake air.
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Improving the combustion performance of a gasoline Rotary Engine by hydrogen enrichment at various conditions
International Journal of Hydrogen Energy, 2018Co-Authors: Shuofeng Wang, Xiaoyu Cong, Lei ShiAbstract:Abstract The combustion process within the cylinder directly influences the thermal efficiency and performance of the Engines. As for the Rotary Engine, the long-narrow combustion chamber prevents the mixture from fully burning, which worsens the performance of the Rotary Engine. As a fuel with excellent properties, hydrogen can improve the combustion of the original Engine. In this paper, improvements in combustion of a gasoline Rotary Engine by hydrogen supplement under different operating conditions were experimentally investigated. The experiment was conducted on a modified hydrogen-gasoline dual-fuel Rotary Engine equipped with an electronically-controlled fuel injection system. An electronic control module was specially made to command the fuel injection, excess air ratio and hydrogen volumetric fraction. Integral heat release fraction (IHRF) was employed to evaluate the combustion of the tested Engine. The tested Engine was first run at the idle speed of 2400 rpm and then operated at 4500 rpm to investigate the combustion of the hydrogen-blended gasoline Rotary Engine under different hydrogen volume fractions, excess air ratios and spark timings. The testing results demonstrated that the combustion of the gasoline Rotary Engine were all improved when the hydrogen was blended into the chamber under all tested conditions.
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Enhancing idle performance of an n-butanol Rotary Engine by hydrogen enrichment
International Journal of Hydrogen Energy, 2018Co-Authors: Shuofeng Wang, Xiaoyu Cong, Lei ShiAbstract:Abstract Rotary Engine generally sustains poor fuel economy and emissions performance at idle condition. Hydrogen has excellent physicochemical properties that can serve as an enhancer to improve the performance of the original Engine. In this paper, a modified Rotary Engine equipped with dual fuel (hydrogen and n-butanol) port injection system and electronic ignition module was developed to explore the influence of hydrogen supplement on enhancing the idle performance of n-butanol Rotary Engine. In this study, the Engine was run at the idle and stoichiometric with the original spark timing. Hydrogen volume percentage in the total intake was gradually increased from 0% to 7.9% by adjusting the fuel flow rate of n-butanol. The experimental results indicated that the Engine instability and fuel energy flow rate were both reduced by enlarging the hydrogen supplying level. Combustion periods were shortened thanks to the enrichment of hydrogen. The peak chamber temperature was heightened as hydrogen fraction increased due to the improved combustion. HC and CO emissions were severally reduced by 50.4% and 85.8% when the hydrogen volume percentage was raised from 0% to 7.9%. However, NOx emissions were mildly increased because of the raised chamber temperature by increasing hydrogen fraction.
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Research on performance of a hydrogen/n-butanol Rotary Engine at idling and varied excess air ratios
Energy Conversion and Management, 2018Co-Authors: Shuofeng Wang, Xiaoyu Cong, Lei ShiAbstract:Abstract The structure chamber of Rotary Engine is irregular compared with traditional reciprocating Engines. Pure n -butanol Rotary Engine normally encounters partial burning and even misfire at idling and lean conditions. Comparatively, hydrogen supplement can ameliorate performance of original Engine. In this paper, experimentation of a Rotary Engine fueled with pure n -butanol and hydrogen/ n -butanol blends at idling and different excess air ratios was conducted. Experimental results manifested that hydrogen addition effectively decreased the Engine instability and fuel energy flow rate. To be specific, fuel energy flow rate at the excess air ratio of 1.05 was reduced from 23.63 MJ/h to 21.26 MJ/h when 3% hydrogen was added. Combustion duration was lowered after introducing hydrogen. Maximum chamber temperature was heightened after hydrogen addition. HC and CO emissions were reduced when 3% hydrogen was added. NOx emissions were reduced when the mixture was leaned out.
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Improving the lean performance of an n-butanol Rotary Engine by hydrogen enrichment
Energy Conversion and Management, 2018Co-Authors: Shuofeng Wang, Lei Shi, Xiaoyu Cong, Jinxin YangAbstract:Abstract The present paper introduced an experiment survey focusing on exploring the impact of hydrogen enrichment on improving the lean-burn performance of an n-butanol Rotary Engine. During the test, the Engine speed and intake pressure were roughly set at 4000 rpm and 35 kPa, respectively. A constant spark advance of 45 °CA was adopted through the test. Hydrogen volumetric fraction of the total intake was severally kept at 0% and 3%. The testing results manifested that the brake thermal efficiency and peak chamber temperature were heightened with hydrogen addition. Besides, the ignition delay and rapid combustion duration were both reduced with the hydrogen additive. Engine running stability gained an improvement by hydrogen supplement. Moreover, HC and CO emissions from the original n-butanol Rotary Engine were reduced after hydrogen adding. NOx emissions were increased with hydrogen enrichment while reduced with the increase of excess air ratio. This indicated that NOx emissions from both the n-butanol and hydrogen-blended n-butanol Rotary Engines could be reduced by lean combustion strategies.
Baowei Fan - One of the best experts on this subject based on the ideXlab platform.
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numerical investigation of direct injection stratified charge combustion in a natural gas diesel Rotary Engine
Applied Energy, 2019Co-Authors: Wei Chen, Jianfeng Pan, Yangxian Liu, Baowei Fan, Hongjun Liu, Peter OtchereAbstract:Abstract To further improve the performance of diesel Rotary Engine, a novel natural gas-diesel Rotary Engine was proposed and studied in this paper. Based on a spray experimental setup, the diesel spray characteristics under diesel Rotary Engine working conditions were obtained and analyzed. Thereafter it was used to validate the spray model for diesel Rotary Engine modeling and simulation. The effect of different natural gas blending ratios on mixture formation and combustion process in the natural gas-diesel Rotary Engine were investigated. Simulation results showed that for fuel-air mixing process, the natural gas movement process was susceptible to the airflow motion. However, the diesel distribution range was obviously enlarged under the influence of high-speed unidirectional flow. At assisted ignition timing, the stratified distributed diesel made the combustion process mainly occured at the front and middle of the combustion chamber. Besides, the flame propagation speed was accelerated with natural gas blending ratio increasing, which effectively improved the total combustion rate. Compared to single-fuel mode, when natural gas blending ratio increased to 20%, the maximum combustion pressure increased by 24.17%. Meanwhile, soot and CO decreased obviously, but NO and CO2 also increased.
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the influence of injection strategy on mixture formation and combustion process in a direct injection natural gas Rotary Engine
Applied Energy, 2017Co-Authors: Baowei Fan, Wei Chen, Jianfeng Pan, Wenming Yang, Stephen BaniAbstract:Abstract The application of direct injection (DI) technology is considered as an effective way to improve the performance of the Rotary Engine. This work seeks to numerically dissect the influence of injection strategy on mixture formation and combustion process in a DI natural gas Rotary Engine. A 3D dynamic simulation model established in our previous work was used to acquire some critical information which was difficult to obtain through experimental investigations. These were the flow field, the fuel distribution, the temperature field and some intermediate concentration fields in the combustion chamber. Simulation results showed that for mixture formation, the motion mechanism of the fuel varies with the injection position. The mass of fuel located at the back of the combustion chamber for injection nozzles A, B and C, was determined by the intensity of vortex I, the coupling function between the value of the impact angle and the intensity of vortex I, and the value of the impact angle respectively. In addition, with retarded injection timing, the accumulation area of fuel for all injection nozzle positions moved from the back to the front of the combustion chamber at ignition timing. For combustion process, the overall combustion rate for the injection strategy (case A4) whose nozzle was 50 mm apart along the Engine major axis and whose injection timing was 360°CA (BTDC), was the fastest. Compared with the out-cylinder premixed gas-filling method (case premix method), the improved combustion rate of case A4 had a 29.7% increase in peak pressure, but also a certain increase in NO emissions.
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effects of hydrogen blending mode on combustion process of a Rotary Engine fueled with natural gas hydrogen blends
International Journal of Hydrogen Energy, 2016Co-Authors: Baowei Fan, Jianfeng Pan, Yuejin Zhu, Wenming Yang, Wei ChenAbstract:Abstract The highly advanced wankel Rotary Engine is a promising energy system because of its favorable energy to weight ratio, multi-fuel capability and large specific power output. This work aims to numerically study the performance, combustion and emission characteristics of a side-ported Rotary Engine fueled with natural gas/hydrogen blends under different hydrogen blending modes. Simulations were performed using multi-dimensional software FLUENT 14.0. On the basis of the software, a three-dimensional dynamic simulation model was established by writing dynamic mesh programs, choosing the RNG k-e turbulent model, the eddy-dissipation concept (EDC) combustion model and a reduced reaction mechanism. The three-dimensional dynamic simulation model based on the chemical reaction kinetics was also validated by the experimental data. Meanwhile, further simulations were then conducted to investigate how to impact the combustion process by the coupling function between hydrogen distribution and the flow field inside the cylinder. Simulation results showed that in order to improve the combustion efficiency, the low-pressure early injection should be used as the hydrogen blending mode. The low-pressure early injection, not only allowed the hydrogen in the combustion chamber to be distributed evenly, but also resulted in the high concentration areas of hydrogen located at the front of the trialing spark plug, which can be used to increase the combustion rate. For the hydrogen low-pressure early injection, the improved combustion rate made in-cylinder pressure and the intermediate OH increase significantly. Compared with no hydrogen induction, it shows a 29% increase in the peak pressures. Meanwhile, the drawback is the increase in NO emissions.
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effects of ignition parameters on combustion process of a Rotary Engine fueled with natural gas
Energy Conversion and Management, 2015Co-Authors: Baowei Fan, Jianfeng Pan, Yangxian Liu, Yuejin ZhuAbstract:Abstract The side-ported Rotary Engine fueled with natural gas is a new, clean, efficient energy system. This work aims to numerically study the performance, combustion and emission characteristics of a side-ported Rotary Engine fueled with natural gas under different ignition positions and ignition timings. Simulations were performed using multi-dimensional software ANASYS Fluent. On the basis of the software, a three-dimensional dynamic simulation model was established by writing dynamic mesh programs and choosing a detailed reaction mechanism. The three-dimensional dynamic simulation model, based on the chemical reaction kinetics, was also validated by the experimental data. Meanwhile, further simulations were then conducted to investigate how to impact the combustion process by the coupling function between ignition operating parameter and the flow field inside the cylinder. Simulation results showed that in order to improve the combustion efficiency, the trailing spark plug should be located at the rear of the tumble zone and the ignition timing should be advanced properly. This was mainly caused by the trailing spark plug being located at the rear of the tumble zone, as it not only allowed the fuel in the rear of combustion chamber to be burnt without delay, but also permitted the acceleration of the flame propagation by the tumble. Meanwhile, with advanced ignition timing, the time between ignition timing and the timing of the tumble disappearance increased, which led to an increase of the tumble effect time used to improve the combustion rate. However, the drawback of this improved combustion was the slight increase in NO emissions. Under the computational condition, when the trailing spark plug scheme of case C coupled with an ignition timing of 50 °CA (BTDC) was compared with the spark plug location and the ignition timing of the original Engine, it showed a 27.4% increase in the peak pressure. Taking the limited increase of NO exhaust into consideration it was the best ignition allocation scheme under the computational condition. This study provided a theoretical foundation for the determination of best ignition position and ignition timing under different working conditions.
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experimental and numerical investigation of the fluid flow in a side ported Rotary Engine
Energy Conversion and Management, 2015Co-Authors: Baowei Fan, Jianfeng Pan, Aikun Tang, Zhenhua Pan, Yuejin Zhu, Hong XueAbstract:Abstract The side-ported Rotary Engine is a potential alternative to the reciprocating Engine because of its favorable performance at low speed. The performance of side-ported Rotary Engines is strongly influenced by the flow field in the combustion chamber. In this study, an optical side-ported Rotary Engine test-bed was built and PIV was employed to measure the flow field in the rotor housing central plane. From experiment results, a counterclockwise swirl was detected in the rotor housing central plane. Meanwhile, a three-dimensional dynamic mesh and turbulent flow model was integrated and simulated using the Fluent CFD software. The three-dimensional dynamic simulation model was validated by comparison with experimental results. In addition, the effect of three major parameters on the flow field in the combustion chamber, namely rotating speed, intake pressure and intake angle were numerically investigated. The results show that a swirl forms in the middle and front of the combustion chamber during the intake stroke under low rotating speed. This is in line with the swirl detected in the rotor housing central plane though the PIV experiment at 600 rpm. Furthermore, the flow field, volume coefficient and average turbulence kinetic energy in the combustion chamber were studied in detail by varying rotating speed, intake pressure and intake angle.
