The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Chen Zhang - One of the best experts on this subject based on the ideXlab platform.
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A Control-Oriented Model for Trajectory-Based HCCI Combustion Control
Journal of Dynamic Systems Measurement and Control-transactions of The Asme, 2018Co-Authors: Chen ZhangAbstract:Previously, the authors have proposed the concept of piston trajectory-based homogeneous charge compression ignition (HCCI) Combustion Control enabled by a free piston engine (FPE) and shown its benefits on both engine thermal efficiency and emissions by implementing various piston trajectories. In order to realize the HCCI trajectory-based Combustion Control in practical applications, a Control-oriented model with sufficient chemical kinetics information has to be developed. In this paper, such a model is proposed and its performance, in terms of computational speed and model fidelity, is compared to three existing models: a simplified model using a one-step global reaction, a reduced-order model using Jones–Lindstedt mechanism, and a complex physics-based model including detailed chemical reaction mechanisms. A unique phase separation method is proposed to significantly reduce the computational time and guarantee the prediction accuracy simultaneously. In addition, the paper also shows that the high fidelity of the proposed model is sustained at multiple working conditions, including different air-fuel ratios (AFR), various compression ratios (CR), and distinct piston motion patterns between the two end positions. Finally, an example is presented showing how the Control-oriented model enables real-time optimization of the HCCI Combustion phasing by varying the trajectories. The simulation results show that the Combustion phasing can be adjusted quickly as desired, which further demonstrates the effectiveness of the piston trajectory-based Combustion Control.
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Trajectory-based Combustion Control for renewable fuels in free piston engines
Applied Energy, 2017Co-Authors: Chen ZhangAbstract:Previously, the authors have developed an advanced Combustion Control, namely the trajectory-based Combustion Control, to further leverage the flexibility of free piston engine (FPE). With the assistance of this Control method, the FPE enables optimization of both engine efficiency and emissions by implementing optimal piston trajectories. Extensive simulations have been conducted to prove the effectiveness of this Combustion Control on fossil fuels. In this paper, the investigation is extended to renewable fuels. Seven renewable fuels are considered herein including hydrogen, biogas, syngas, ethanol, dimethyl ether (DME), biodiesel, and Fischer-Tropsch fuel. The influences of both compression ratio (CR) and piston motion pattern between the two dead centers on the Combustion process are considered in the study, which demonstrates the ultimate fuel flexibility and large tolerance of fuel impurity possessed by the FPE. In addition, the simulation results show that at a fixed CR, the thermal efficiency of the FPE can still be enhanced (5% in DME case) by varying the piston motion patterns alone. Furthermore, specific asymmetric piston trajectories are synthesized to further improve the engine thermal efficiency (8% in hydrogen case) and reduce the NOx emission simultaneously (around 70% reduction in hydrogen case). In other words, due to its ultimate fuel flexibility, large tolerance of fuel impurity, and Controllable piston trajectory, the FPE, with the trajectory-based Combustion Control, enables a co-optimization of renewable fuels and engine operation.
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A New Approach to Reduce Engine-Out Emissions Enabled by Trajectory-Based Combustion Control
Volume 1: Adaptive and Intelligent Systems Control; Advances in Control Design Methods; Advances in Non-Linear and Optimal Control; Advances in Roboti, 2015Co-Authors: Chen ZhangAbstract:Previously, the authors have proposed the concept of piston trajectory-based Combustion Control enabled by free piston engines (FPE). With this novel Control method, the FPE realizes in-cycle real-time Combustion Control, in terms of adjusting the ignition timing and manipulating the in-cylinder temperature trace, through various piston trajectories and achieves higher thermal efficiency compared to the conventional internal Combustion engines. In this paper, the effects of this new Combustion Control on engine-out emissions are studied. First, a model is developed that includes different piston trajectories in the FPE, a convective heat loss sub model and a reduced n-heptane reaction mechanism with major emissions species from diesel engines. Afterwards, a new approach which reduces the engine-out emissions by employing novel piston trajectories is described. At last, analyses of the simulation results demonstrating the variable piston trajectories’ effects on CO and NOx emissions are presented, which further reveal the advantages of the trajectory-based Combustion Control.Copyright © 2015 by ASME
Jianhua Zhang - One of the best experts on this subject based on the ideXlab platform.
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Modeling and simulation for boiler Combustion Control system of 1000MW ultra-supercritical unit
The 26th Chinese Control and Decision Conference (2014 CCDC), 2014Co-Authors: Pengcheng Jiang, Xiaobin Zheng, Jianhua ZhangAbstract:Taking the 1000MW ultra-supercritical once-through boiler as a research object, the Combustion process of boiler is analyzed through principles of energy transferring, heat exchange, and mass flow balances. Since the complete and accurate model of boiler Combustion is the basis of performance study and optimizing Control, a mechanism mathematical model of boiler Combustion Control system is built up in this paper. It is the first time that boiler Combustion Control system has successfully covered the coal mill pulverizing system, and this model consists of the other three Controlled variables subsystems: main steam pressure Control system, furnace pressure Control system and flue gas oxygen content Control system. Furthermore, this paper gives the simulation of the mechanism mathematical model and analyzes the response curves of the outputs after giving each input a step disturbance respectively at two different load conditions. The results of the simulation show that the mathematical model is reasonable and effective.
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Improvement of boiler Combustion Control performance using probability density function shaping and particle swarm optimization
2008 2nd International Symposium on Systems and Control in Aerospace and Astronautics, 2008Co-Authors: Jianhua Zhang, Bin Tian, Jinfang ZhangAbstract:A novel scheme for boiler Combustion Control system is proposed, where the firing rate demand is represented by furnace temperature distribution (FTD). In this scheme, the firing rate is defined to be FTD which characterizes the status of Combustion directly. A real-time FTD shape Control system is formulated and applied to boiler Combustion Control. FTD is fed back to Combustion Controller and adjusted by fuel valve actuators. Compared with the gradient approach, particle swarm optimization (PSO) is used to solve the Control input, the simulation results verify the effectiveness of the proposed scheme.
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Combustion Control using B-Spline Based Furnace Temperature Distribution
2007 International Conference on Machine Learning and Cybernetics, 2007Co-Authors: Jianhua Zhang, Bin Tian, Jinfang ZhangAbstract:This paper presents a closed-loop Combustion Control algorithm for a coal-fired boiler using the recently developed output distribution Control theory. The furnace temperature distribution (FTD) is regarded as the Controlled variable, which demonstrates the stability, economy and reliability of Combustion process. Following the FTD obtained by Fluent simulation software, the equivalent B-spline FTD model is then established. Consequently, the Control strategy is provided so as to ensure the output FTD will follow the desired distribution. The simulation study shows the effectiveness of the proposed approach.
Xiaobin Zheng - One of the best experts on this subject based on the ideXlab platform.
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Application of ADRC approach in ultra-supercritical unit Combustion Control system for energy efficiency improvement
2017 Chinese Automation Congress (CAC), 2017Co-Authors: Yuzhao Huang, Congzhi Huang, Xiaobin ZhengAbstract:Nowadays, developing ultra-supercritical (USC) units is considered to be a necessary measure to relieve the tension of energy deficiency. The Combustion system is a typical system with large time delays and complex couplings. Since the outputs of Combustion Control system are directly relevant to unit's economization, the Control performances of the Combustion system are closely related with energy efficiency. Active Disturbance Rejection Control (ADRC) approach is widely applied in industrial process Control field due to its outstanding Control performance and the simplicity of design. In this paper, a Combustion Control system of USC unit is established firstly. Then, PID and ADRC approach are applied in this system. The simulation result shows that the proposed approach achieve better Control performance than PID, which can improve operational economy and enhance energy utilization efficiency.
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Modeling and simulation for boiler Combustion Control system of 1000MW ultra-supercritical unit
The 26th Chinese Control and Decision Conference (2014 CCDC), 2014Co-Authors: Pengcheng Jiang, Xiaobin Zheng, Jianhua ZhangAbstract:Taking the 1000MW ultra-supercritical once-through boiler as a research object, the Combustion process of boiler is analyzed through principles of energy transferring, heat exchange, and mass flow balances. Since the complete and accurate model of boiler Combustion is the basis of performance study and optimizing Control, a mechanism mathematical model of boiler Combustion Control system is built up in this paper. It is the first time that boiler Combustion Control system has successfully covered the coal mill pulverizing system, and this model consists of the other three Controlled variables subsystems: main steam pressure Control system, furnace pressure Control system and flue gas oxygen content Control system. Furthermore, this paper gives the simulation of the mechanism mathematical model and analyzes the response curves of the outputs after giving each input a step disturbance respectively at two different load conditions. The results of the simulation show that the mathematical model is reasonable and effective.
Stephen Yurkovich - One of the best experts on this subject based on the ideXlab platform.
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a real time pressure estimation algorithm for closed loop Combustion Control
Mechanical Systems and Signal Processing, 2013Co-Authors: Ahmed Aldurra, Marcello Canova, Stephen YurkovichAbstract:Abstract The cylinder pressure is arguably the most important variable characterizing the Combustion process in internal Combustion engines. In light of the recent advances in Combustion technologies and in engine Control, the use of cylinder pressure is now frequently considered as a feedback signal for closed-loop Combustion Control algorithms. In order to generate an accurate pressure trace for real-time Combustion Control and diagnostics, the output of the in-cylinder pressure transducer must be conditioned with signal processing methods to mitigate the well-known issues of offset and noise. While several techniques have been proposed for processing the cylinder pressure signal with limited computational burden, most of the available methods still require one to apply low-pass filters or moving average windows in order to mitigate the noise. This ultimately limits the opportunity of exploiting the in-cylinder pressure feedback for a cycle-by-cycle Control of the Combustion process. To this extent, this paper presents an estimation algorithm that extracts the pressure signal from the in-cylinder sensor in real-time, allowing for estimating the 50% burn rate location and IMEP on a cycle-by-cycle basis. The proposed approach relies on a model-based estimation algorithm whose starting point is a crank-angle based engine Combustion model that predicts the in-cylinder pressure from the definition of a burn rate function. Linear parameter varying (LPV) techniques are then used to expand the region of estimation to cover the engine operating map, as well as allowing for real-time cylinder estimation during transients. The estimator is tested on the experimental data collected on an engine dynamometer as well as on a high-fidelity engine simulator. The results obtained show the effectiveness of the estimator in reconstructing the cylinder pressure on a crank-angle basis and in rejecting measurement noise and modeling errors, with considerably low computation effort.
Chun Xiao - One of the best experts on this subject based on the ideXlab platform.
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A New Cast Stone Roller Kiln and its Combustion Control Approach
Advanced Materials Research, 2012Co-Authors: Jing Chen, You Xin Yuan, Chun Xiao, Wang Lin Wang, Zhong Xiang Li, He Cai Li, Zhuo ChenAbstract:The domestic cast stone industrial production is of high energy consumption and low productivity, so a new cast stone roller kiln is firstly developed. A Combustion Control approach is advanced to accommodate the new roller kiln architecture and meet the Combustion Control requirements. Continuous proportion and pulse Control methods are adopted to the high-speed isothermal burners with internal dense distribution. Two Controllers mutually collaborated in pairs to obtain the internal uniform temperature. The implementation of the Combustion Control scheme is put forward. The application results demonstrated that the new roller kiln and Combustion Controller could effectively decrease the furnace temperature difference, increase stability of the Combustion atmosphere, improve product quality, reduce energy consumption and NOx emissions.
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Pulse Combustion Control Technology for Oxygen Atmosphere
2009 International Workshop on Intelligent Systems and Applications, 2009Co-Authors: Chen Jing, You Xin Yuan, Huang Bihui, Chun XiaoAbstract:A new Combustion Control method for oxygen-enriched or pure-oxygen ceramic roller kilns is proposed in this paper. This kind of roller kiln uses high-concentration oxygen or pure oxygen as the Combustion-supporting medium. The new method introduces the pulse Combustion Control technology into the ceramic roller kiln to fine tune its oxygen-and-gas proportional regulator. This technology can greatly improve the Combustion performance and thermal efficiency. It also meets the requirements of the sintering process well. This paper first analyzes the significance of this research by comparative analysis, and then discusses the configuration and implementation of the Control system. Finally it gives the hardware and software design for the whole system. This system can automatically regulate the ratio of oxygen to fuel gas and the pulse Combustion time of the mixed gas. In practice, it optimizes the Combustion atmosphere, improves the thermal efficiency and products quality and reduces energy consumptions.