The Experts below are selected from a list of 76269 Experts worldwide ranked by ideXlab platform
Min Kuang - One of the best experts on this subject based on the ideXlab platform.
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aerodynamic characteristics within a cold small scale model for a down fired 350 mwe utility boiler applying a multiple injection and multiple staging technology effect of the staged air declination angle
Experimental Thermal and Fluid Science, 2012Co-Authors: Zhengqi Li, Min Kuang, Yan ZhangAbstract:Abstract This work presents an experimental staged-air angle optimization for a forthcoming ultra-low NO x retrofit within a down-fired pulverized-coal 350 MW e utility boiler. By recording aerodynamic field measurements within a small-scale model of the furnace, cold Airflow experiments were conducted at seven different angle settings of 0°, 15°, 30°, 35°, 40°, 45° and 50°. At the four smaller angle settings, a deflected flow field characterized by the downward Airflow near the front wall reversing upward far earlier than that near the rear wall, developed in the lower furnace. Accordingly, in the furnace throat region overfire air penetrated much further near the front arch than near the rear arch. Certain cross-sectional velocity component distributions and the decaying in Airflows displayed poor symmetries along the furnace center. With increasing the angle from 0° to 35°, the flow-field deflection weakened continually. At the three larger angle settings, a well-formed symmetric flow field appeared in the lower furnace and the furnace throat region. Increasing the staged-air angle decreased sharply the difference in the downward Airflow reach near the front and rear walls initially in the range of 0–45° but then varied it slightly in the angles of 45–50°. An optimal staged-air declination angle of 45° was recommended according to the present experiment results.
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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.
Zhengqi Li - One of the best experts on this subject based on the ideXlab platform.
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aerodynamic characteristics within a cold small scale model for a down fired 350 mwe utility boiler applying a multiple injection and multiple staging technology effect of the staged air declination angle
Experimental Thermal and Fluid Science, 2012Co-Authors: Zhengqi Li, Min Kuang, Yan ZhangAbstract:Abstract This work presents an experimental staged-air angle optimization for a forthcoming ultra-low NO x retrofit within a down-fired pulverized-coal 350 MW e utility boiler. By recording aerodynamic field measurements within a small-scale model of the furnace, cold Airflow experiments were conducted at seven different angle settings of 0°, 15°, 30°, 35°, 40°, 45° and 50°. At the four smaller angle settings, a deflected flow field characterized by the downward Airflow near the front wall reversing upward far earlier than that near the rear wall, developed in the lower furnace. Accordingly, in the furnace throat region overfire air penetrated much further near the front arch than near the rear arch. Certain cross-sectional velocity component distributions and the decaying in Airflows displayed poor symmetries along the furnace center. With increasing the angle from 0° to 35°, the flow-field deflection weakened continually. At the three larger angle settings, a well-formed symmetric flow field appeared in the lower furnace and the furnace throat region. Increasing the staged-air angle decreased sharply the difference in the downward Airflow reach near the front and rear walls initially in the range of 0–45° but then varied it slightly in the angles of 45–50°. An optimal staged-air declination angle of 45° was recommended according to the present experiment results.
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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.
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.
Michael D Sohn - One of the best experts on this subject based on the ideXlab platform.
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coupling fast fluid dynamics and multizone Airflow models in modelica buildings library to simulate the dynamics of hvac systems
Building and Environment, 2017Co-Authors: Wei Tian, Thomas Alonso Sevilla, Wangda Zuo, Michael D SohnAbstract:Multizone models are widely used in building Airflow and energy performance simulations due to their fast computing speed. However, multizone models assume that the air in a room is well mixed, consequently limiting their application. In specific rooms where this assumption fails, the use of computational fluid dynamics (CFD) models may be an alternative option. Previous research has mainly focused on coupling CFD models and multizone models to study Airflow in large spaces. While significant, most of these analyses did not consider the coupled simulation of the building Airflow with the building's Heating, Ventilation, and Air-Conditioning (HVAC) systems. This paper tries to fill the gap by integrating the models for HVAC systems with coupled multizone and CFD simulations for Airflows, using the Modelica simulation platform. To improve the computational efficiency, we incorporated a simplified CFD model named fast fluid dynamics (FFD). We first introduce the data synchronization strategy and implementation in Modelica. Then, we verify the implementation using two case studies involving an isothermal and a non-isothermal flow by comparing model simulations to experiment data. Afterward, we study another three cases that are deemed more realistic. This is done by attaching a variable air volume (VAV) terminal box and a VAV system to previous flows to assess the capability of the models in studying the dynamic control of HVAC systems. Finally, we discuss further research needs on the coupled simulation using the models.
Yan Zhang - One of the best experts on this subject based on the ideXlab platform.
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aerodynamic characteristics within a cold small scale model for a down fired 350 mwe utility boiler applying a multiple injection and multiple staging technology effect of the staged air declination angle
Experimental Thermal and Fluid Science, 2012Co-Authors: Zhengqi Li, Min Kuang, Yan ZhangAbstract:Abstract This work presents an experimental staged-air angle optimization for a forthcoming ultra-low NO x retrofit within a down-fired pulverized-coal 350 MW e utility boiler. By recording aerodynamic field measurements within a small-scale model of the furnace, cold Airflow experiments were conducted at seven different angle settings of 0°, 15°, 30°, 35°, 40°, 45° and 50°. At the four smaller angle settings, a deflected flow field characterized by the downward Airflow near the front wall reversing upward far earlier than that near the rear wall, developed in the lower furnace. Accordingly, in the furnace throat region overfire air penetrated much further near the front arch than near the rear arch. Certain cross-sectional velocity component distributions and the decaying in Airflows displayed poor symmetries along the furnace center. With increasing the angle from 0° to 35°, the flow-field deflection weakened continually. At the three larger angle settings, a well-formed symmetric flow field appeared in the lower furnace and the furnace throat region. Increasing the staged-air angle decreased sharply the difference in the downward Airflow reach near the front and rear walls initially in the range of 0–45° but then varied it slightly in the angles of 45–50°. An optimal staged-air declination angle of 45° was recommended according to the present experiment results.