Optimization of a cascade control loop for circulating irrigation of a distillation column of the atmospheric block of an electric desalting plant

2021 ◽  
Author(s):  
Ekaterina A. Shulaeva ◽  
Lyubov A. Satchikhina
Keyword(s):  
Distillation Column ◽  
Cascade Control ◽  
Control Loop ◽  
Electric Desalting

The Application of Cascade Control Based on DMC in Stripping Section Temperature Control System

2014 ◽  
Vol 651-653 ◽  
pp. 891-894
Author(s):  
Jian Ping Xiao ◽  
Tong Song
Keyword(s):  
Time Delay ◽  
Predictive Control ◽  
Distillation Column ◽  
External Disturbance ◽  
Static Characteristic ◽  
Cascade Control ◽  
Temperature Control System ◽  
Lower Accuracy ◽  
Internal Mechanism ◽  
Better Than

Predictive control is one of the robust control algorithms that suitable for computerized implementation, and requests lower accuracy of the model. It has been widely used in process control recently. Considering the features of distillation column stripping section, such as complex internal mechanism, time-varying parameters and large time delay, the DMC-PID cascade control strategy is adopted. The simulation results show that this strategy combined the advantages of predictive control and cascade control, can make distillation column stripping section have good dynamic and static characteristic in the presence of external disturbance and time delay. The performances are better than DMC and conventional PID control.

Cascade control strategy for external carbon dosage in predenitrifying process

2002 ◽  
Vol 45 (4-5) ◽  
pp. 53-60 ◽  
Author(s):  
J.-H. Cho ◽  
S.W. Sung ◽  
I.-B. Lee
Keyword(s):  
Control Strategy ◽  
Disturbance Rejection ◽  
Nitrate Concentration ◽  
Cascade Control ◽  
Control Loop ◽  
Relay Feedback ◽  
Point Tracking ◽  
Pi Controllers ◽  
Good Set

We propose a cascade control strategy composed of two Proportional-Integral (PI) controllers to regulate the nitrate concentration in the predenitrifying process by manipulating the external carbon dosage. It controls the nitrate concentrations in the effluent as well as in the final anoxic reactor simultaneously to strictly satisfy the quality of the effluent as well as to remove the effects of disturbances more quickly. The design of two PI controllers in the cascade control loop can be completed with the Ziegler–Nichols (Z–N) tuning rule together with a simple relay feedback identification method. Results from the Benchmark simulation confirm that both good set point tracking and satisfactory disturbance rejection can be guaranteed due to the structural advantages of the proposed cascade control strategy. Also, compared with a previous work, the fluctuation of the nitrate concentration in the effluent has been decreased significantly.

Comparing Usage of Temperature Control and Composition Control for Reactive Distillation Column in Methyl Ester Production

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
Kulchanat Prasertsit ◽  
Chakrit Tongurai ◽  
Chokchai Mueanmas
Keyword(s):  
Methyl Ester ◽  
Temperature Control ◽  
Distillation Column ◽  
Reactive Distillation ◽  
The Other ◽  
Base Case ◽  
Control Performance ◽  
Control Loop ◽  
Composition Control ◽  
And Performance

The temperature control and the composition control for the production process was used to evaluated a method to control the quality of methyl ester production in a reactive distillation column. The optimum condition at steady state was selected as the base case condition for the control study by using Aspen Dynamic Simulation. In this work, two controller settings for PID controller of each control loop were based on the Zeigler-Nichol and the Tyreus-Luyben tuning formulae. The controllability and performance of both control structures were compared. The result shows that the control loop using the Ziegler-Nichols setting gave better control performance than the other using the Tyreus-Luyben setting. It also found that the control structure based on temperature control gives the same control performance as the other based on composition control, but less expensive and less complicated to implement.

scholarly journals Cascade Control of Coffee Roasting Degree in a Spouted Bed Batch Process Based on a Real-Time Imaging Analysis

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Omar R. Gómez-Gómez ◽  
Guadalupe M. Guatemala-Morales ◽  
J. Paulo García-Sandoval ◽  
Enrique Arriola-Guevara
Keyword(s):  
Real Time ◽  
Control Algorithm ◽  
Batch Process ◽  
Cascade Control ◽  
Control Loop ◽  
Spouted Bed ◽  
Experimental Implementation ◽  
Reference Images ◽  
Processing Techniques ◽  
Coffee Roasting

On this work, the experimental implementation of a cascade control algorithm to regulate coffee roasting degree in a batch spouted bed process is presented. The control algorithm is composed of an inner control loop that regulates the temperature of the hot air inflow used to roast coffee grains inside a spouted bed, while an outer control loop, based on imaging processing techniques, tracks on real time the coffee roasting degree and decides if the inflow air temperature must be modified. To achieve this goal, a colour-matching algorithm is used to compare a colour spectrum obtained from images acquired on real time, from a peephole on the spouted bed, with the colour spectrums of several reference images with different degrees of roasting. Match scores are computed based on the similarity between the colour spectrums. With the match scores, a roasting index is finally calculated to assess the degree of roasting, allowing to automatically track the roasting progress to decide if the batch roasting process has achieved the desired roasting degree. The experimental results show that the control scheme is able to robustly achieve the desired roasting degree with excellent effectiveness.

Diagnosis of Cascade Control Loop Status Using Performance Analysis Based Approach

2006 ◽  
Vol 45 (22) ◽  
pp. 7540-7551 ◽  
Author(s):  
Junghui Chen ◽  
Yuezhi Yea ◽  
Cho-Kai Kong
Keyword(s):  
Performance Analysis ◽  
Cascade Control ◽  
Control Loop
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