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To assist in the absorption of renewable energy, coal-fired power plants need to operate over a wide range of loads, which exacerbates the challenge of the time delay in the wet desulphurization process. Therefore, this paper proposes a new control structure based on frequency retrofit and a corresponding model predictive controller to change the traditional idea of wet desulphurization control. This structure provides faster control actions, thus reducing time delay directly. And it makes the original discrete control variable continuous, enabling most control methods. The field application to the wet flue gas desulphurization system reveals the practical prospects of the proposed control structure and simulations have been conducted to verify the merits of the proposed control scheme based on data collected from a 1000 MW power plant.

Dynamic model is the foundation to achieve feedback control of Electrostatic Precipitator (ESP) so as to reduce dust emission concentration and high power consumption. This paper investigates the dynamic modeling of outlet dust concentration of a dry electric precipitator with five electric field structure in a 1000MW power plant. The secondary current of the high-frequency power supply of the last two electric fields of the ESP are taken as control inputs, whereas the outlet dust concentration is taken as output. With increasingly stepping the secondary current at four typical load points, experimental data of outlet dust concentration are collected to identify parameters of dynamic models after fixing its structure based on an immune genetic algorithm. The experimental results suggest that the established dynamic models can capture the real dynamics of ESP and have high accuracy.

In this work, carbon quantum dots (CQDs) have been synthesized by one step hydrothermal method to detect hydrogen peroxide (H2O2). The optical H2O2 sensors were based on the fluorescent quenching of the carbon quantum dots. The optical H2O2 sensors demonstrate capable of detecting H2O2 over the range of 0-88.2 mM and 0-60 mM. The H2O2 sensitivities of wavelength shift to changes in the H2O2 concentration were found to be 0.18 nm/mM and 0.26 nm/mM. These results of the optical sensors showed that the method can be used in practice detection of H2O2 and could offer a new approach for developing a new optical biosensor. The CQDs exhibit good emission property and high stability, as well as excitation-independent emission behavior. Moreover, it is attractive that CQDs can be used as an effective fluorescent probe for the detection of H2O2 with linear Stern-Volmer plot and wavelength shift in an aqueous solution.