Expert control for a stable operation of a partial nitrification system to treat highly concentrated ammonium wastewater

2009 ◽  
Vol 60 (5) ◽  
pp. 1191-1199 ◽  
Author(s):  
Irene Jubany ◽  
Julián Carrera ◽  
Javier Lafuente ◽  
Juan Antonio Baeza
Keyword(s):  
Control System ◽  
Pilot Plant ◽  
Control Strategies ◽  
Biomass Concentration ◽  
High Strength ◽  
Partial Nitrification ◽  
Stable Operation ◽  
Ammonium Oxidation ◽  
Expert Control ◽  
Biomass Activity

This work presents the application of expert control strategies for a successful and stable operation of partial nitrification. A high-strength ammonium wastewater was treated in a continuous pilot plant with a configuration of three reactors in series plus a settler. The system was operated at mild temperature (around 25°C) and at high sludge retention time to obtain a significant nitrifying biomass concentration. The implemented control system with expert supervisory rules provided a stable and robust operation of the partial nitrification system even when the pilot plant was subjected to several disturbances as change in influent concentration, failure of aeration in one reactor and operation with variable biomass concentration. The control system was based on local feedback control loops for dissolved oxygen and pH with proper setpoints for nitrite oxidizing bacteria (NOB) inhibition and an inflow control loop based on Oxygen Uptake Rate (OUR) measurements, which allowed working at the current maximum ammonium oxidation capacity. Two additional expert rules were implemented for automatically determine the required OUR setpoint in accordance with the biomass activity and to produce a fast load decrease when a system overload was detected.

Research on Integrated Control System of the Gas Pressure in Coke Oven

2013 ◽  
Vol 397-400 ◽  
pp. 1214-1219
Author(s):  
Xia Bai ◽  
Da Lu Guan ◽  
Chen Rui
Keyword(s):  
Control System ◽  
Control Strategies ◽  
Integrated Control ◽  
Control Object ◽  
Coke Oven ◽  
Pressure Control ◽  
Expert Control ◽  
Control Scheme ◽  
Hardware Reliability ◽  
Pressure Control System

This paper combines hardware reliability and software mobility with modern intelligent control through the analysis of the control object using intelligent decoupling control scheme to control the pressure control system of the large gas collector in coke oven. By using expert control strategies based on the DCS, the paper develops the system design which is versatile and effective.

Nitrous oxide formation during nitritation and nitrification of high-strength wastewater

2013 ◽  
Vol 67 (11) ◽  
pp. 2494-2502 ◽  
Author(s):  
Yvonne Schneider ◽  
Maike Beier ◽  
Karl-Heinz Rosenwinkel
Keyword(s):  
Nitrous Oxide ◽  
High Strength ◽  
Dominant Factor ◽  
Process Conditions ◽  
Stable Operation ◽  
Ammonium Oxidation ◽  
Formation Factor ◽  
N2o Formation ◽  
Operational Conditions ◽  
Oxidation Rates

The purpose of this study was to investigate the formation of nitrous oxide (N2O) in nitritation and nitrification under stable, comparable and not limiting conditions typical for treatment of high-strength wastewater. A laboratory-scale aerated chemostat was operated with reject water at different sludge retention times, achieving suppression of nitrate formation by wash-out of nitrite-oxidizing bacteria for nitritation. The N2O formation factor during stable nitritation was higher (2.90% N2O-N /NH4−-Nox) than during nitrification (0.74%). The positive correlation of N2O formation rates and ammonium oxidation rates was linear and thus did not contribute to changes of the N2O formation factor. The dominant factor for N2O formation during stable operation was high nitrite concentration, which was positively correlated with N2O formation rates. The highest formation factors were observed during a transition phase from nitrification to nitritation with unstable process conditions (4.81%) and during a short-term experiment with increased pH of 7 (10.28%). The results indicate that even with operational conditions that are regarded favourable for the process of nitritation N2O formation can be limited but not avoided.

The Application of Safety and Stability Control Device in Middle of Henan Power Grid

2013 ◽  
Vol 860-863 ◽  
pp. 2068-2072
Author(s):  
Li Hua Zhang ◽  
Hui Lin Wang ◽  
Hong Qing Gan
Keyword(s):  
Control System ◽  
Power System ◽  
Control Strategies ◽  
Stability Control ◽  
Control Device ◽  
The Other ◽  
Stable Operation ◽  
Secondary Line ◽  
Stability Control System ◽  
Safety And Stability

Safety and stability control device is the secondary line of defense of power system stable operation. Firstly, this paper proposed the requisite of the regional safety and stability control system installed in Wuzhou 500kV switching station and the other two stations which belonged to the middle Henan power system. And then, it presented the components and elaborated control strategies of the system. It listed the situations of the united testing, at last, it summarized notes of this safety and stability control system in daily operation.

scholarly journals Impact of Various Feed Properties on the Performance of a Control System for a Multiple Dividing Wall Column Pilot Plant

2021 ◽  
Vol 5 (2) ◽  
pp. 29
Author(s):  
Ulrich Preißinger ◽  
Goran Lukač ◽  
Igor Dejanović ◽  
Thomas Grützner
Keyword(s):  
Control System ◽  
Dynamic Simulation ◽  
Pilot Plant ◽  
Suboptimal Control ◽  
Stable Operation ◽  
Control Structures ◽  
Dividing Wall Column ◽  
Column Design

Despite the attractive savings potential of multiple Dividing Wall Columns (mDWC), there are no reports in the open literature of an existing application so far. In this perspective, the control of mDWCs has been a rather little-investigated field. Pilot plants are a necessary step needed to further expand the application window of this sustainable distillation technology. This contribution aimed to show that mDWCs are sufficiently flexible, providing stable operation, even with suboptimal control structures arising from design limitations imposed by equipment. For this purpose, the pilot column design was assessed using dynamic simulation to evaluate its operability in case of different disturbances as well as different feed mixtures. The results showed that, in all cases, the column could be stabilized and product purities maintained. This suggests that even complex configurations such as mDWCs offer sufficient amount of flexibility to allow for the application of one design in different services.

The circulating floating bed reactor: effect of particle size distribution of the carrier on ammonia conversion

2000 ◽  
Vol 41 (4-5) ◽  
pp. 393-400 ◽  
Author(s):  
J.M. Garrido-Fernandez ◽  
R. Méndez ◽  
J.M. Lema ◽  
V. Lazarova
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
G Protein ◽  
Biomass Concentration ◽  
Biomass Accumulation ◽  
Ammonia Removal ◽  
Operating Conditions ◽  
Nitrification Rate ◽  
Ammonia Conversion ◽  
Biomass Activity

Three Circulating Floating Bed Reactors (CFBR) R1, R2 and R3 with 20% v/v of a plastic carrier with different size distribution were operated to study the effect of the particles size of the carrier on biomass accumulation and nitrification performance. Operating conditions were similar in the three systems: ammonia concentrations around 50 mg-N–NH4+/ L, ammonia loading rates up to 1.2 kg N–NH4+/m3·d and temperatures between 14 and 27°C. Accumulation of nitrite was observed until day 65th. This w as result both of the inhibition of nitrite oxidation by free ammonia until day 20th and the insignificant accumulation of a biomass with low nitrite oxidising capacity between days 20 and 65th. Ammonia conversion rate and removal efficiency were higher in the reactor with lower particle size, R3 (nitrification rate of 1.1 kg N–NH4+/m3·d and ammonia removal of 97% at 16°C), than in R2 or R1 (nitrification rate of 1.0 kg N–NH4+/m3·d and ammonia removal of 90% at 16°C). The better efficiency in R3 was obtained as a result of the higher specific surface of the biofilm developed. Biomass activity was similar in the three reactors (2.2 and 1.12 g N/g protein · d at 30 and 15°C, respectively). Both the biomass evolution with time and biomass retention in the systems was practically not influenced by the size of particle. Biomass concentration of 1.2 g protein/L was retained in the carrier and up to 20% of the newly produced biomass was retained in the CFBRs.

An Expert Controller Based on Transient Response Patterns

2011 ◽  
Vol 219-220 ◽  
pp. 3-7
Author(s):  
Ning Zhang ◽  
Rong Hua Liu
Keyword(s):  
Control System ◽  
Transient Response ◽  
Closed Loop ◽  
Performance Criterion ◽  
Response Patterns ◽  
Loop Control ◽  
Expert Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Control Decision

An expert control system based on transient response patterns and expert system techniques is proposed in this paper. Depending on the features of the closed-loop control system determines the control decision and adjusts the parameters of the controller. The proposed method requires minimal proper information about the controlled plant and, with the linear re-excitation learning method, the system is kept satisfying the performance criterion.

Design and Experimental Implementation of Longitudinal Control for a Platoon of Automated Vehicles

1998 ◽  
Vol 122 (3) ◽  
pp. 470-476 ◽  
Author(s):  
R. Rajamani ◽  
S. B. Choi ◽  
B. K. Law ◽  
J. K. Hedrick ◽  
R. Prohaska ◽  
...  
Keyword(s):  
Control System ◽  
Torque Converter ◽  
Stable Operation ◽  
Automated Vehicles ◽  
Longitudinal Control ◽  
The Public ◽  
Automated Highways ◽  
Experimental Implementation ◽  
Special Challenge ◽  
Upper Level

This paper presents the design and experimental implementation of a longitudinal control system for the operation of automated vehicles in platoons. The control system on each vehicle is designed to have a hierarchical structure and consists of an upper level controller and a lower level controller. The upper controller determines the desired acceleration for each vehicle in the platoon so as to maintain safe string-stable operation even at very small intervehicle spacing. The lower controller utilizes vehicle-specific parameters and determines the throttle and/or brake commands required to track the desired acceleration. A special challenge handled in the design of the lower level controller is low-speed operation that involves gear changes and torque converter dynamics. The paper also presents the design of longitudinal intra-platoon maneuvers that are required in order to allow any car in the platoon to make an exit. The paper presents extensive experimental results from the public NAHSC demonstration of automated highways conducted in August 1997 at San Diego, California. The demonstration included an eight-car platoon operating continuously over several weeks with passenger rides given to over a thousand visitors. The maneuvers demonstrated included starting the automated vehicles from complete rest, accelerating to cruising speed, allowing any vehicle to exit from the platoon, allowing new vehicles to join the platoon and bringing the platoon to a complete stop at the end of the highway. [S0022-0434(00)01903-1]

Coal-Conveying Control System for the Pressure of Coal Waste Heat Power Generation Based on PLC

2013 ◽  
Vol 336-338 ◽  
pp. 681-685
Author(s):  
Li Jun Zhao ◽  
Ying Feng Chen
Keyword(s):  
Control System ◽  
Waste Heat ◽  
Computer Control ◽  
System Structure ◽  
Utilization Rate ◽  
Coal Waste ◽  
Stable Operation ◽  
Efficient Operation ◽  
Actual Operation ◽  
One Year

This paper constructs a coal-conveying control system based on programmable logic controller (PLC), which is applied to the residual heat and pressure integrated energy-saving technological transformation projects, and realizes the performance of security, reliable and efficient operation. This control system consists of the PLC control system, computer control system and industrial television monitoring system. After more than one year of actual operation shows that the system structure is reasonable, reliable operation, at the same time, reduce labor intensity, improve the utilization rate of equipment, the stable operation also provides a practical reference for other similar projects.

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