The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Pengfei Yang - One of the best experts on this subject based on the ideXlab platform.
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staged Air Ratio optimization for a new down fired technology within a cold small scale model of a 350 mwe utility boiler
Energy & Fuels, 2011Co-Authors: Min Kuang, Zhengqi Li, Pengfei YangAbstract:In this paper, a new combustion technology based on the concept of multiple injection and multiple staging was developed especially for a down-fired pulverized-coal 350 MW e utility boiler with particularly high NO x emissions and severe asymmetric combustion. Compared to the prior technique, the new technology creates a completely unique combustion system necessitating a burner redesign and reconfiguRation. To establish efficient furnace operating conditions for the reconfigured furnace, an appropriate range for the staged-Air Ratio must be ascertained. For this purpose, cold Airflow experiments were conducted by recording aerodynamic field measurements within a small-scale model at various staged-Air Ratio settings (viz., 0%, 10%, 20%, 25%, 30%, and 35%). Aerodynamic fields and distributions of velocities throughout the furnace were measured, in addition to decay and penetRation depths of downward Airflows and overfire Air. At lower staged-Air Ratios of 0%, 10%, 20%, and 25%, a well-formed symmetric flow field appeared in the lower furnace and the furnace throat region. Velocity distribution, as well as the decays in the downward Airflow and OFAjets, also displayed well-defined symmetries along the furnace center in the zones near the front and rear walls. At higher Ratios of 30% and 35%, a deflected flow field developed in the lower furnace, as well as in the furnace throat region, although this Airflow was redirected higher up the front wall than for the rear wall. To establish a strongly symmetric flow field and appropriate penetRation depths, a staged-Air Ratio of 25% was found optimal for the newly reconfigured furnace.
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staged Air Ratio optimization within a cold small scale model for a mbel down fired pulverized coal 300 mw electrical utility boiler
Energy & Fuels, 2010Co-Authors: Min Kuang, Qunyi Zhu, Pengfei YangAbstract:To eliminate large combustion differences between zones near the front and rear walls, as well as to decrease the high carbon content in the fly ash in Mitsui Babcock energy limited (MBEL) down-fired pulverized-coal boilers, a 45° staged-Air declination method was put forward in our previous work. To establish optimal staged-Air Ratio settings with this staged-Air declination, cold Airflow experiments were conducted within a small-scale model of a MBEL down-fired pulverized-coal 300 MW (electrical) utility boiler. We investigated the aerodynamic field at six different staged-Air Ratio settings of 0, 10, 15, 20, 25, and 30%. At the setting of 0%, an essentially symmetric W-shaped flow field appeared in the lower furnace, although some asymmetries arose in the dry bottom hopper and zones near the staged-Air port outlet. For settings of 10, 15, 20, and 25%, a well-formed symmetric W-shaped flow field appeared in the lower furnace, and the extent of the flow field symmetry along the furnace center in the zone...
Min Kuang - One of the best experts on this subject based on the ideXlab platform.
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staged Air Ratio optimization for a new down fired technology within a cold small scale model of a 350 mwe utility boiler
Energy & Fuels, 2011Co-Authors: Min Kuang, Zhengqi Li, Pengfei YangAbstract:In this paper, a new combustion technology based on the concept of multiple injection and multiple staging was developed especially for a down-fired pulverized-coal 350 MW e utility boiler with particularly high NO x emissions and severe asymmetric combustion. Compared to the prior technique, the new technology creates a completely unique combustion system necessitating a burner redesign and reconfiguRation. To establish efficient furnace operating conditions for the reconfigured furnace, an appropriate range for the staged-Air Ratio must be ascertained. For this purpose, cold Airflow experiments were conducted by recording aerodynamic field measurements within a small-scale model at various staged-Air Ratio settings (viz., 0%, 10%, 20%, 25%, 30%, and 35%). Aerodynamic fields and distributions of velocities throughout the furnace were measured, in addition to decay and penetRation depths of downward Airflows and overfire Air. At lower staged-Air Ratios of 0%, 10%, 20%, and 25%, a well-formed symmetric flow field appeared in the lower furnace and the furnace throat region. Velocity distribution, as well as the decays in the downward Airflow and OFAjets, also displayed well-defined symmetries along the furnace center in the zones near the front and rear walls. At higher Ratios of 30% and 35%, a deflected flow field developed in the lower furnace, as well as in the furnace throat region, although this Airflow was redirected higher up the front wall than for the rear wall. To establish a strongly symmetric flow field and appropriate penetRation depths, a staged-Air Ratio of 25% was found optimal for the newly reconfigured furnace.
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staged Air Ratio optimization within a cold small scale model for a mbel down fired pulverized coal 300 mw electrical utility boiler
Energy & Fuels, 2010Co-Authors: Min Kuang, Qunyi Zhu, Pengfei YangAbstract:To eliminate large combustion differences between zones near the front and rear walls, as well as to decrease the high carbon content in the fly ash in Mitsui Babcock energy limited (MBEL) down-fired pulverized-coal boilers, a 45° staged-Air declination method was put forward in our previous work. To establish optimal staged-Air Ratio settings with this staged-Air declination, cold Airflow experiments were conducted within a small-scale model of a MBEL down-fired pulverized-coal 300 MW (electrical) utility boiler. We investigated the aerodynamic field at six different staged-Air Ratio settings of 0, 10, 15, 20, 25, and 30%. At the setting of 0%, an essentially symmetric W-shaped flow field appeared in the lower furnace, although some asymmetries arose in the dry bottom hopper and zones near the staged-Air port outlet. For settings of 10, 15, 20, and 25%, a well-formed symmetric W-shaped flow field appeared in the lower furnace, and the extent of the flow field symmetry along the furnace center in the zone...
Kadir Aydin - One of the best experts on this subject based on the ideXlab platform.
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investigation of combustion characteristics and emissions in a spark ignition engine fuelled with natural gas hydrogen blends
International Journal of Hydrogen Energy, 2009Co-Authors: Nafiz Kahraman, Orhan S Akansu, Bilge Albayrak Ceper, Kadir AydinAbstract:Abstract In this study, an experimental study on the performance and exhaust emissions of a spark-ignition engine fuelled with methane–hydrogen mixtures (100% CH4, 10% H2 + 90% CH4, 20% H2 + 80% CH4, and 30% H2 + 70% CH4) were performed at different engine speeds and different excessive Air Ratios. This present work was carried out on a Ford engine. This is a four-stroke cycle four-cylinder spark-ignition engine with a bore of 80.6 mm, a stroke of 88 mm and a compression Ratio of 10:1. Experiments were performed at 1500, 2000, 2500 and 3000 rpm and at wide open throttle (WOT). CO, CO2 and HC emission values and cylinder pressure were measured. The results showed that while the speed and excessive Air Ratio increase, CO emission values decrease. The reduction of HC and CO emissions could be obtained by adding hydrogen into the natural gas when operating on the lean mixture condition. Increasing the excessive Air Ratio also decreases the maximum peak cylinder pressure.
Zhengqi Li - One of the best experts on this subject based on the ideXlab platform.
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promotion of anthracite burnout for a 300 mwe down fired boiler with a novel combustion technology
Energy & Fuels, 2018Co-Authors: Qingxiang Wang, Zhichao Chen, Lingyan Zeng, Zhengqi LiAbstract:Eccentric-swirl-secondary-Air combustion technology (ESSACT) has been applied to a 300 MWe anthracite- and down-fired boiler with swirl burners. To improve burnout performance of the retrofitted boiler, the effects of primary Air Ratios on flow and combustion characteristics are investigated via cold-model aerodynamic experiments and industrial experiments. When primary Air Ratios are 17.09 and 19.08%, a deflective flow field occurs, and with increasing the primary Air Ratio from 21.11 to 24.75%, a symmetrical “W” flow field is formed. With increasing the primary Air Ratio from 17.09 to 24.75%, the maximum dimensionless vertical velocity of Air flow near the front wall increases linearly from 0.364 to 0.521. Accordingly, the penetRation depth in the real boiler increases by approximately 2.88 m. For a primary Air Ratio of 18.47%, the temperatures at the burner exit and in the furnace hopper near the front and rear walls are both seriously asymmetrical and the combustion path of pulverized coal particles b...
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factors affecting the downward flame depth in a 600 mw down fired boiler incorporating multiple injection and multiple staging technology
Energy, 2017Co-Authors: Lingyan Zeng, Zhengqi Li, Minhang Song, Xiaoguang Li, Zhichao ChenAbstract:Considering the excessively deep flame depth existing in a 600 MW down-fired boiler incorporating multiple-injection and multiple-staging technology, 1:20 scale aerodynamic tests were conducted to incrementally improve factors responsible for the deep flame depth. These trials demonstrated that, in all cases, the downward velocity near the wing walls decayed more rapidly than that near the furnace center. Increasing the mass Ratio of pulverized coal in fuel-rich flow to that in fuel-lean flow and reducing the secondary Air Ratio while simultaneously increasing the tertiary Air Ratio was found to increase the penetRation depth. Increasing the distance between adjacent burners, optimally lowering the fuel-rich and fuel-lean flow velocities, and reducing the secondary Air velocity all decreased the penetRation depth. The comprehensively improved downward Airflow depth and Air flux into the furnace hopper were reduced by 6.3% and 14.9%, respectively. Cold-state Airflow tracing tests were performed in an actual boiler, the improved downward Airflow depth reduced apparently, which was consistent with the results from modeling tests. Industrial-scale hot-state experiments determined improved hopper near-wall temperatures of 700–800 °C near the furnace center (values that were lower than those of 800–900 °C near the wing walls). These values were approximately 450 °C less than the prior temperatures at the same location, indicating the flame penetRation depth was greatly reduced.
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staged Air Ratio optimization for a new down fired technology within a cold small scale model of a 350 mwe utility boiler
Energy & Fuels, 2011Co-Authors: Min Kuang, Zhengqi Li, Pengfei YangAbstract:In this paper, a new combustion technology based on the concept of multiple injection and multiple staging was developed especially for a down-fired pulverized-coal 350 MW e utility boiler with particularly high NO x emissions and severe asymmetric combustion. Compared to the prior technique, the new technology creates a completely unique combustion system necessitating a burner redesign and reconfiguRation. To establish efficient furnace operating conditions for the reconfigured furnace, an appropriate range for the staged-Air Ratio must be ascertained. For this purpose, cold Airflow experiments were conducted by recording aerodynamic field measurements within a small-scale model at various staged-Air Ratio settings (viz., 0%, 10%, 20%, 25%, 30%, and 35%). Aerodynamic fields and distributions of velocities throughout the furnace were measured, in addition to decay and penetRation depths of downward Airflows and overfire Air. At lower staged-Air Ratios of 0%, 10%, 20%, and 25%, a well-formed symmetric flow field appeared in the lower furnace and the furnace throat region. Velocity distribution, as well as the decays in the downward Airflow and OFAjets, also displayed well-defined symmetries along the furnace center in the zones near the front and rear walls. At higher Ratios of 30% and 35%, a deflected flow field developed in the lower furnace, as well as in the furnace throat region, although this Airflow was redirected higher up the front wall than for the rear wall. To establish a strongly symmetric flow field and appropriate penetRation depths, a staged-Air Ratio of 25% was found optimal for the newly reconfigured furnace.
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Bituminous coal combustion in a full-scale start-up ignition burner: Influence of the excess Air Ratio
Energy, 2010Co-Authors: Zhengqi Li, Weiguang Kong, Yang Lu-zhao, Zhichao ChenAbstract:A start-up ignition burner has been proposed to reduce oil fuel consumption during the firing-up process and partial-load opeRation. To investigate the influence of different excess Air Ratios on bituminous coal combustion in the start-up ignition burner, full-scale reacting-flow experiments were performed for an experiment setup. The ignition burner was identical to that normally used in an 800 MWe utility boiler. Gas temperature distributions in the burner were obtained for excess Air Ratios of 0.56, 0.75, 0.98 and 1.14 (corresponding to primary Air velocities of 17, 23, 30 and 35 m/s). Coal burnout and the release of C and H were observed at the exit of the burner nozzle. Gases such as O2 and CO were measured at the center of the burner. A change in resistance was obtained within the burner.
Shuofeng Wang - One of the best experts on this subject based on the ideXlab platform.
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lean burn performance of a hydrogen blended gasoline engine at the wide open throttle condition
Applied Energy, 2014Co-Authors: Shuofeng Wang, Bo Zhang, Xiaolong LiuAbstract:Abstract The performance of a hydrogen-blended gasoline engine at lean and the wide open throttle conditions was investigated. A hydrogen port-injection system was adopted to introduce the hydrogen into each cylinder. The engine was operated at 1400 rpm and two hydrogen blending levels of 0% and 3%. The excess Air Ratio was raised from 1.00 to about 1.45 for a given hydrogen addition fraction. The test results demonstrated that the hydrogen blending contributed to the raised thermal efficiency and shortened flame development and propagation duRations. An increased brake mean effective pressure was found after the hydrogen addition only at lean conditions. For both stoichiometric and lean conditions, the hydrogen blending was beneficial for reducing the engine cyclic variation. This provides a possibility to run a hydrogen-blended gasoline engine with the fully opened throttle position and control the engine torque only by adjusting the excess Air Ratio. Toxic emissions including HC, CO and particulate were reduced after the hydrogen blending.
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cyclic variation in a hydrogen enriched spark ignition gasoline engine under various operating conditions
International Journal of Hydrogen Energy, 2012Co-Authors: Shuofeng WangAbstract:Abstract In this paper, the cyclic variation characteristics of a hydrogen-enriched gasoline engine under various operating conditions were experimentally investigated. The test was carried out on a modified four-cylinder gasoline engine equipped with an electronically controlled hydrogen injection system. A hybrid electronic control unit was developed to govern the injection timings and duRations of hydrogen and gasoline to accomplish the on-line adjusting of the hydrogen blending level and excess Air Ratio. The engine was first run at idle condition with an idle speed of 790 rpm and then operated at 1400 rpm to investigate the cyclic variation in a hydrogen-blended gasoline engine at different hydrogen volume fractions in the total intake, excess Air Ratios, spark timings and manifolds absolute pressures. The test results demonstrated that the coefficient of variation in indicated mean effective pressure was distinctly decreased with the increase of hydrogen blending Ratio. At 1400 rpm and a manifolds absolute pressure of 61.5 kPa, the relevant excess Air Ratio for the engine lean burn limit was extended from 1.45 to 2.55 when the hydrogen volume fraction in the intake was raised from 0% to 4.5%. Besides, for a specified hydrogen addition level, the coefficient of variation in indicated mean effective pressure was continuously increased but the coefficient of variation in the peak cylinder pressure was first raised and then decreased with the increase of excess Air Ratio. The experimental results also showed that hydrogen addition was more effective on reducing engine cyclic variation at low loads rather than at high loads.