Modern chemicalprocesses are usually characterized by large scale,multiple operation units,and high dynamic,and monitoring of these processes is *** paper proposes a genetic algorithm(GA)-regularized dynamic canonica...
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Modern chemicalprocesses are usually characterized by large scale,multiple operation units,and high dynamic,and monitoring of these processes is *** paper proposes a genetic algorithm(GA)-regularized dynamic canonical correlation analysis(DCCA)-based concurrent modeling and monitoring scheme for multi-unit dynamic ***,the DCCA modeling is performed between each unit and the entire process to characterize both cross-correlation and auto-correlation among ***,the GA regularization is performed for each unit to explore communicating variables and reduce the communication *** a residual-based local fault detector is established for each unit,which performs fault detection by considering both the variables of the local unit and the information provided by its related units,and therefore exhibits superior monitoring *** proposed monitoring scheme is applied on a numerical example and an industrial tail gas treatment *** results demonstrate the feasibility and efficiency of the proposed approach.
Dissociation of methyl nitrite is the first step during CO catalytic coupling to dimethyl oxalate followed by hydrogenation to ethyl glycol in a typical coal to liquid process. In this work, the first-principle calcul...
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Dissociation of methyl nitrite is the first step during CO catalytic coupling to dimethyl oxalate followed by hydrogenation to ethyl glycol in a typical coal to liquid process. In this work, the first-principle calculations based on density functional theory were performed to explore the reaction mechanism for the non-catalytic dissociation of methyl nitrite in the gas phase and the catalytic dissociation of methyl nitrite on Pd(111) surface since palladium supported on alpha-alumina is the most effective catalyst for the coupling. For the non-catalytic case, the calculated results show that the CH_3O–NO bond will break with a bond energy of 1.91 eV, and the produced CH_3O radicals easily decompose to formaldehyde, while the further dissociation of formaldehyde in the gas phase is difficult due to the strong C–H bond. On the other hand, the catalytic dissociation of methyl nitrite on Pd(111) to the adsorbed CH_3O and NO takes place with a small energy barrier of 0.03 eV. The calculated activation energies along the proposed reaction pathways indicate that(i) at low coverage, a successive dehydrogenation of the adsorbed CH_3O to CO and H is favored while(ii) at high coverage, hydrogenation of CH_3O to methanol and carbonylation of CH_3O to methyl formate are more preferred. On the basis of the proposed reaction mechanism,two meaningful ways are proposed to suppress the dissociation of methyl nitrate during the CO catalytic coupling to dimethyl oxalate.
Offline updating is a method that most of multiple model soft-sensors used to adapt the new operating conditions. Replacing online models with offline ones is bound to affect the efficiency of soft-sensors, and it cos...
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In the process of chemical production, the phenomenon of control valve's stiction is very common. This phenomenon causes control loop oscillation and has a negative effect on the quality and cost of the product. T...
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In this study, a novel online operating performance assessment method based on multi-sets two-step basis vector extraction artificial neural networks (MTBVE-ANN) strategy is proposed for industrial applications. The M...
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An improved nonlinear adaptive switching control method is presented to relax the assumption on the higher order nonlinear terms of a class of discrete-time non-affine nonlinear systems. The proposed control strategy ...
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An improved nonlinear adaptive switching control method is presented to relax the assumption on the higher order nonlinear terms of a class of discrete-time non-affine nonlinear systems. The proposed control strategy is composed of a linear adaptive controller, a neural network(NN) based nonlinear adaptive controller and a switching mechanism. An incremental model is derived to represent the considered system and an improved robust adaptive law is chosen to update the parameters of the linear adaptive controller. A new performance criterion of the switching mechanism is designed to select the proper controller. Using this control scheme, all the signals in the system are proved to be bounded. Numerical examples verify the effectiveness of the proposed algorithm.
Styrene is one of the most important monomers in the petrochemical industry. In this study, a novel methodology for tight integration of Real-Time Optimization (RTO) and Model Predictive control (MPC) is applied to an...
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The variable-speed, variable-pitch speed wind turbines are widely used in the wind-energy system. However, the fluctuation of power generation is serious because of the erratic speed of wind and the nonlinearity of th...
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ISBN:
(纸本)9781509015740;9781509015733
The variable-speed, variable-pitch speed wind turbines are widely used in the wind-energy system. However, the fluctuation of power generation is serious because of the erratic speed of wind and the nonlinearity of the energy conversion systems (ECS). How to keep the ECS work well during the whole operating region is a challenge issue. In this paper, a multiple model predictive control (MMPC) using the state estimation is present to solve this issue. The whole operating region is divided into several sub-regions according to the wind's speed, in which several linear models and corresponding MPCs are constructed. The state variables of each local model are estimated by using the Kalman filter. A new switching criterion without perturbation is present to keep the MMPC works well at the different operating region switching. Considering the operating constraints, a quadratic programming procedure is used to calculate the optimal value of MMPC. Comparing the conventional PI controller, the proposed control achieves a good performance and reduces the fluctuation of power generation. Simulation results show the excellent performance of the present method.
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