scholarly journals Multimodel Anomaly Identification and Control in Wet Limestone-Gypsum Flue Gas Desulphurization System

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Xiaoli Li ◽  
Quanbo Liu ◽  
Kang Wang ◽  
Fuqiang Wang ◽  
Guimei Cui ◽  
...  
Keyword(s):  
Flue Gas ◽  
Sulphur Dioxide ◽  
High Performance ◽  
Power Plants ◽  
Control Method ◽  
Control Strategies ◽  
Air Pollutant ◽  
Process Data ◽  
Whole Process ◽  
Flue Gas Desulphurization

Sulphur dioxide, as one of the most common air pollutant gases, brings considerable numbers of hazards on human health and environment. For the purpose of reducing the detrimental effect it brings, it is of urgent necessity to control emissions of flue gas in power plants, since a substantial proportion of sulphur dioxide in the atmosphere stems from flue gas generated in the whole process of electricity generation. However, the complexity and nondeterminism of the environment increase the occurrences of anomalies in practical flue gas desulphurization system. Anomalies in industrial desulphurization system would induce severe consequences and pose challenges for high-performance control with classical control strategies. In this article, based on process data sampled from 1000 MW unit flue gas desulphurization system in a coal-fired power plant, a multimodel control strategy with multilayer parallel dynamic neural network (MPDNN) is utilized to address the control problem in the context of different anomalies. In addition, simulation results indicate the applicability and effectiveness of the proposed control method by comparing with different cases.

The Investigation of the Optimization Scheme of the Low-cycle Fatigue Cropping Based on the Acoustic Emission Technique

2021 ◽  
Author(s):  
Yujian Ren ◽  
Jingxiang Li ◽  
Yuanzhe Dong ◽  
Dong Jin ◽  
Shengdun Zhao
Keyword(s):  
Acoustic Emission ◽  
High Frequency ◽  
Control Method ◽  
Low Cycle Fatigue ◽  
Control Strategies ◽  
Low Frequency ◽  
Loading Frequency ◽  
Cycle Fatigue ◽  
Al 6061 ◽  
Whole Process

Abstract High efficiency and good section quality are two main objectives of metal bar cropping. A suitable control method can help to achieve both goals. An investigation of the control method of low-cycle fatigue cropping (LCFC) based on the acoustic emission (AE) technique has been proposed in this study. Ring-down counts and kurtosis are used to monitor the whole process of LCFC. The results showed that kurtosis is more suitable for monitoring the LCFC process and as a critical parameter to optimize the control method than ring-down counts in the noisy factory environment.Moreover, three types of materials are studied in this experiment; by combine with the AE results, macroscopic images and microscopic images of sections, characteristics of various LCFC stages are obtained. The results also indicated reduce the area of the transient fracture zone is the key to improve the section quality. Reducing the load frequency before the unstable crack propagation stage will beneficial to realize the goals. Based on the evaluation of kurtosis, an optimized control method is presented, and two control parameters: transient time T and the critical value of the slope of kurtosis C are determined. For 16Mn, 1045 and Al 6061, the T is 5s, 10s, and 1s, respectively. For 16Mn, 1045, and Al 6061, the C is 100, 300, and 0, respectively. Two parameters, h and S, are used to evaluate the section quality and four control strategies are compared. The results indicate the optimal control methods can improve the section quality effectively. The influence trend of reducing loading frequency is investigated by further comparison. It can be seen as the frequency decreases, the efficiency of the section quality improving decreases. In order to realize the optimal results, different control strategies are adopted for different materials. Strategy 1 (high frequency is 20Hz，high frequency thought the whole process), strategy 2 (high frequency is 20Hz，low frequency is 8.33Hz), and strategy 3 (high frequency is 20Hz，low frequency is 6.67Hz) is suitable for Al 6061, 1045, and 16Mn, respectively.

scholarly journals Analyses of the Control System Strategies and Methodology for Part Power Control of the Simple and Intercooled Recuperated Brayton Helium Gas Turbine Cycles for Generation IV Nuclear Power Plants

2017 ◽  
Vol 3 (4) ◽  
Author(s):  
A. Gad-Briggs ◽  
P. Pilidis ◽  
T. Nikolaidis
Keyword(s):  
Control System ◽  
Inventory Control ◽  
Nuclear Power ◽  
Power Plants ◽  
Control Method ◽  
Control Strategies ◽  
Limiting Factors ◽  
Cycle Performance ◽  
Study Results ◽  
And Performance

An important requirement for Generation IV Nuclear Power Plant (NPP) design is the control system, which enables part power operability. The choices of control system methods must ensure variation of load without severe drawbacks on cycle performance. The objective of this study is to assess the control of the NPP under part power operations. The cycles of interest are the simple cycle recuperated (SCR) and the intercooled cycle recuperated (ICR). Control strategies are proposed for NPPs but the focus is on the strategies that result in part power operation using the inventory control method. First, results explaining the performance and load limiting factors of the inventory control method are documented; subsequently, the transient part power performances are also documented. The load versus efficiency curves were also derived from varying the load to understand the efficiency penalties. This is carried out using a modeling and performance simulation tool designed for this study. Results show that the ICR takes ∼102% longer than the SCR to reduce the load to 50% in design point (DP) performance conditions for similar valve flows, which correlates with the volumetric increase for the ICR inventory tank. The efficiency penalties are comparable for both cycles at 50% part power, whereby a 22% drop in cycle efficiency was observed and indicates limiting time at very low part power. The analyses intend to aid the development of cycles for Generation IV NPPs specifically gas cooled fast reactors (GFRs) and very high-temperature reactors (VHTRs), where helium is the coolant.

Advanced Coal-Fired Power Plants

2000 ◽  
Vol 123 (1) ◽  
pp. 4-9 ◽  
Author(s):  
Lawrence A. Ruth
Keyword(s):  
Power Systems ◽  
Flue Gas ◽  
High Performance ◽  
Power Plants ◽  
Pilot Scale ◽  
Combined Cycle ◽  
Department Of Energy ◽  
Electric Power Plants ◽  
Air Temperatures ◽  
Low Emission

The U.S. Department of Energy is partnering with industry to develop advanced coal-fired electric power plants that are substantially cleaner, more efficient, and less costly than current plants. Low-emission boiler systems (LEBS) and high-performance power systems (HIPPS) are based, respectively, on the direct firing of pulverized coal and the indirectly fired combined cycle. LEBS uses a low-NOx slagging combustion system that has been shown in pilot-scale tests to emit less than 86 g/GJ (0.2 lb/106 Btu) of NOx. Additional NOx removal is provided by a moving bed copper oxide flue gas cleanup system, which also removes 97–99 percent of sulfur oxides. Stack levels of NOx can be reduced to below 9 g/GJ (0.02 lb/106 Btu). Construction of an 80 MWe LEBS proof-of-concept plant is scheduled to begin in the spring of 1999. Engineering development of two different HIPPS configurations is continuing. Recent tests of a radiant air heater, a key component of HIPPS, have indicated the soundness of the design for air temperatures to 1150°C. LEBS and HIPPS applications include both new power plants and repowering/upgrading existing plants.

Research on Servo System for CNC Machine Tool Driven by Permanent Magnet Synchronous Torque Motor

2012 ◽  
Vol 562-564 ◽  
pp. 1505-1508
Author(s):  
Mu Lan Wang ◽  
Kai Yun Xu ◽  
Chuan He ◽  
Lei Zhou
Keyword(s):  
Machine Tool ◽  
Permanent Magnet ◽  
High Performance ◽  
Control Method ◽  
Control Strategies ◽  
Servo System ◽  
Numerical Control ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Control Machine Tool

Permanent Magnet Synchronous Torque Motor (PMSTM) has the main characteristics of low speed, high torque, high precision and excellent stability, which can be applied to implement the direct driving technology for CNC (Computer Numerical Control) machine tool. In this paper, the mathematical model of PMSTM is simply introduced, and the various control strategies are discussed in detail. According to the requirement of high performance for PMSTM driving servo system in CNC machine tool, the corresponding suitable control method is employed in the feed servo system. The proposed scheme is also promoted to apply in the spindle system, the tool holder and the turntable of machine tool.

The Preparation and Current Situation of Ce and Mn Catalyst

2013 ◽  
Vol 864-867 ◽  
pp. 1612-1615
Author(s):  
Wen Long Zhen ◽  
Rui Tang Guo ◽  
Wei Guo Pan ◽  
Yan Wu Gao ◽  
Chao Lin Shi
Keyword(s):  
Flue Gas ◽  
Power Plants ◽  
Catalytic Reduction ◽  
Reduction Process ◽  
Air Pollutant ◽  
Photochemical Smog ◽  
Environmental Friendly ◽  
Secondary Pollution ◽  
Temperature Window ◽  
Low Temperature Scr

NOx is the main air pollutant of coal-fired power plants, which is one of the important reasons to cause pollution such as acid rain, photochemical smog and so on. Selective catalytic reduction process is the major technology for reducing NOx emissions from coal-fired power plants. However, the commercial vanaidia-based catalyst is active within a narrow temperature window of 300-400°C, easily to be deacticed by SO2 in the flue gas. And the formation of N2O and toxicity of vanaidia cause secondary pollution. Therefore, it is of more importance to develop a new environmental-friendly catalyst for low temperature SCR with high activity.

scholarly journals Multiple-TMD-Based Structural Vibration Control for Pumped Storage Power Plants

2020 ◽  
Vol 10 (16) ◽  
pp. 5577
Author(s):  
Tengfei Zhong ◽  
Xin Feng ◽  
Yu Zhang ◽  
Jing Zhou
Keyword(s):  
Vibration Control ◽  
High Frequency ◽  
Power Plants ◽  
Control Method ◽  
Control Strategies ◽  
High Order Mode ◽  
Structural Vibration ◽  
Power Station ◽  
High Frequency Vibration ◽  
Pumped Storage

The high-frequency resonance in the superstructure of a pumped storage power station (PSPP) due to the generation unit can shorten the service life of the power station structure and even endanger its safety. Although tuned mass dampers (TMDs) have been proved to be effective in controlling structural vibration, their application in PSPPs is rare, as high-frequency vibration control of PSPPs has not been studied. In this paper, a TMD control method is proposed based on PSPP high-frequency vibration and various TMD control strategies, and a set of high-frequency TMD equipment is designed. Results of a series of vibration reduction tests and numerical analyses show that the new TMD device can effectively control the high-order mode of the structure, and the bandwidth of the suppression frequency is extended, which shows the robustness and control efficiency of the device.

scholarly journals Sulphite measurement and its influence on Hg behaviour in wet-limestone flue-gas desulphurization

Clean Energy ◽  
2020 ◽  
Author(s):  
Ida Masoomi ◽  
Sophia Bruttel ◽  
Marc Oliver Schmid ◽  
Günter Scheffknecht
Keyword(s):  
Gas Phase ◽  
Gas Sensor ◽  
Measurement Technique ◽  
Flue Gas ◽  
Sulphur Dioxide ◽  
Reducing Agent ◽  
Characteristic Wavelength ◽  
Light Absorbance ◽  
Flue Gas Desulphurization

Abstract The most abundant and typical reducing agent for oxidized mercury in the slurry of wet flue-gas desulphurization (FGD) is the absorbed sulphur dioxide (SO2), which is present as different species of bisulphite or sulphite, depending on the pH of the slurry. In this study, two different measurement principles for continuous sulphite measurement in the slurry of lab-scale FGD were investigated to check their feasibility to be implemented in a wet FGD. The first method is based on light absorbance at the characteristic wavelength of sulphite measurement using a spectrophotometer and, in the second method, sulphite is measured as sulphur dioxide using a gas sensor. In addition, the correlation of sulphite concentration and mercury (Hg) in the slurry can be shown by measuring sulphite semi-continuously. It was concluded that using a spectrophotometer leads to distorted results. In contrast, measuring sulphite as SO2 in the gas phase proved to be more selective. The implementation of the measurement technique in the lab-scale FGD showed promising results for sulphite measurement. Thus, the correlation of Hg and sulphite concentration could be shown at different synthetic slurries containing different halides. Using a slurry without halides demonstrated the ambivalent influence of sulphite in reactions involving Hg, in which sulphite acts as a ligand for Hg complexes as well as a reducing agent, depending on the existing concentration. However, in the presence of halides, the role of sulphite was less significant.

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