Journal of Liaoning Petrochemical University
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Dynamic Matrix Control of Thermal Efficiency of Tubular Furnace Based on PSO Algorithm
Haojie Ye, Wenna Li
Abstract119)   HTML8)    PDF (848KB)(130)      

In the research on the thermal efficiency of atmospheric tube heating furnaces, it is necessary to conduct effective online measurement of thermal efficiency and select relatively reliable advanced control methods. On the basis of the research on the combustion mechanism of the heating furnace, the online measurement method based on the principle and data processing is used to process the thermal efficiency, and the "dynamic matrix control" is introduced in the process of optimizing the control of the heating furnace efficiency, which is compared with the traditional control method. The introduction of dynamic matrix control makes the system have a better control effect. At the same time, the "particle swarm algorithm" was selected to optimize the parameters of dynamic matrix control. In the optimization process of dynamic matrix parameters, the particle swarm algorithm relatively shortens the optimization time and improves the control quality, so as to achieve a more satisfactory control effect. Finally, compare with internal model control, it shows that dynamic matrix control can achieve relatively better control effect.

2023, 43 (3): 81-85. DOI: 10.12422/j.issn.1672-6952.2023.03.013
Improved Genetic Algorithm to Optimize Differences Control of Heater Bypass
Weiming Wang, Wenna Li
Abstract136)   HTML5)    PDF (1235KB)(118)      

Aiming at the problem of temperature tracking and balance control of each branch pipe of the heating furnace, an improved genetic algorithm was proposed to optimize the multi?deviation control of the temperature tracking and balance of the branch pipe temperature of the heating furnace. The scheme used the temperature deviation of the raw materials of each branch pipe after mixing and the temperature deviation of each branch pipe. By adjusting the feed flow rate and fuel flow rate, it not only ensured that the flow rate of the main pipe is constant during the regulation process, but also realized the dual goal of temperature tracking and balance of each pass. Multi?passes are analyzed as a whole, so the temperature comparison of adjacent branch pipes was avoided repeatedly. At the same time, the improved genetic algorithm was used to optimize the controller parameters of the differences control technique, which overcomes the difficulty of controller parameter tuning. The simulation results show the feasibility and effectiveness of the improved genetic algorithm to optimize the differences control scheme.

2023, 43 (1): 73-79. DOI: 10.12422/j.issn.1672-6952.2023.01.013
Image Watermarking Algorithm Based on Wavelet Transform⁃Hessenberg Matrix⁃Singular Value Decomposition
Wenna Li
Abstract221)   HTML13)    PDF (1403KB)(337)      

In order to improve the balance between invisibility and robustness of image watermarking, a color image watermarking algorithm is studied by using wavelet transform and Heisenberg array decomposition (HAD) singular value decomposition (SVD). Firstly, the host image and watermark image are transformed through color space color space, then the host image is transformed by wavelet transform, then the low frequency coefficients are decomposed by HAD and SVD, and the watermark is embedded after SVD in the low frequency. The experimental results show that the proposed watermarking method has strong robustness against multiple watermarking attacks, which is reflected by the normalized correlation NC of the objective evaluation criteria of extracted watermarks. The host image has good invisibility after embedded watermark, which is reflected by objective evaluation standard peak signal?to?noise ratio (PSNR) and structural similarity of images (SSIM). It can embed grayscale or color large watermark with strong ability of embedding information. It is concluded that that the watermarking method has a certain application value.

2022, 42 (5): 84-89. DOI: 10.3969/j.issn.1672-6952.2022.05.013
Application of SKPCA⁃LSSVM Model in Gasoline Dry Point Prediction
Liying Guo, Wenna Li, Xianming Lang
Abstract268)   HTML    PDF (880KB)(166)      

The dry point of gasoline on the top of atmospheric tower is closely related to product quality, but it is difficult to measure the gasoline dry point online, and the soft sensor is a technical way to solve the estimation and control prediction of such variables. Due to the complexity of atmospheric and vacuum distillation process, the correlation between the variables increases. In this paper, sparse principal component analysis (SPCA) was introduced into kernel principal component analysis(KPCA) algorithm, and the input variables of the model were selected by sparse kernel principal component analysis(SKPCA) algorithm. The nonlinear dimensionality reduction between data was realized, the principal component structure was simplified, and the sparsity of principal component variables was increased. The selected sparse principal components were used as the input of the least squares support vector machine (LSSVM), and the soft sensor prediction model for the top dry point of atmospheric tower was established. The simulation results show that the SKPCA?LSSVM model has higher prediction accuracy and superior model performance compared with the traditional PCA?LSSVM and KPCA?LSSVM methods.

2022, 42 (3): 74-78. DOI: 10.3969/j.issn.1672-6952.2022.03.013