Control of Flow Rate in Heavy-Oil Pipelines Using PD and PID Controller

Author(s):  
Sina Razvarz ◽  
Raheleh Jafari ◽  
Alexander Gegov
Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4325
Author(s):  
Zhihua Wang ◽  
Yunfei Xu ◽  
Yi Zhao ◽  
Zhimin Li ◽  
Yang Liu ◽  
...  

Wax deposition during crude oil transmission can cause a series of negative effects and lead to problems associated with pipeline safety. A considerable number of previous works have investigated the wax deposition mechanism, inhibition technology, and remediation methods. However, studies on the shearing mechanism of wax deposition have focused largely on the characterization of this phenomena. The role of the shearing mechanism on wax deposition has not been completely clarified. This mechanism can be divided into the shearing dispersion effect caused by radial migration of wax particles and the shearing stripping effect caused by hydrodynamic scouring. From the perspective of energy analysis, a novel wax deposition model was proposed that considered the flow parameters of waxy crude oil in pipelines instead of its rheological parameters. Considering the two effects of shearing dispersion and shearing stripping coexist, with either one of them being the dominant mechanism, a shearing dispersion flux model and a shearing stripping model were established. Furthermore, a quantitative method to distinguish between the roles of shearing dispersion and shearing stripping in wax deposition was developed. The results indicated that the shearing mechanism can contribute an average of approximately 10% and a maximum of nearly 30% to the wax deposition process. With an increase in the oil flow rate, the effect of the shearing mechanism on wax deposition is enhanced, and its contribution was demonstrated to be negative; shear stripping was observed to be the dominant mechanism. A critical flow rate was observed when the dominant effect changes. When the oil flow rate is lower than the critical flow rate, the shearing dispersion effect is the dominant effect; its contribution rate increases with an increase in the oil flow temperature. When the oil flow rate is higher than the critical flow rate, the shearing stripping effect is the dominant effect; its contribution rate increases with an increase in the oil flow temperature. This understanding can be used to design operational parameters of the actual crude oil pipelines and address the potential flow assurance problems. The results of this study are of great significance for understanding the wax deposition theory of crude oil and accelerating the development of petroleum industry pipelines.


Author(s):  
Nathan Schroeder ◽  
Henk Laubscher ◽  
Brantley Mills ◽  
Clifford K. Ho

Abstract Falling particle receivers (FPRs) are being studied in concentrating solar power applications to enable high temperatures for supercritical CO2 (sCO2) Brayton power cycles. The falling particles are introduced into the cavity receiver via a linear actuated slide gate and irradiated by concentrated sunlight. The thickness of the particle curtain associated with the slide-gate opening dimension dictates the mass flow rate of the particle curtain. A thicker, higher mass flow rate, particle curtain would typically be associated with a smaller temperature rise through the receiver, and a thinner, lower mass flow rate, particle curtain would result in a larger temperature rise. Using the receiver outlet temperature as the process variable and the linear actuated slide gate as the input parameter a proportional, integral, and derivative (PID) controller was implemented to control the temperature of the particles leaving the receiver. The PID parameters were tuned to respond in a quick and stable manner. The PID controlled slide gate was tested using the 1 MW receiver at the National Solar Thermal Test Facility (NSTTF). The receiver outlet temperature was ramped from ambient to 800°C then maintained at the setpoint temperature. After reaching a steady-state, perturbations of 15%–20% of the initial power were applied by removing heliostats to simulate passing clouds. The PID controller reacted to the change in the input power by adjusting the mass flow rate through the receiver to maintain a constant receiver outlet temperature. A goal of ±2σ ≤ 10°C in the outlet temperature for the 5 minutes following the perturbation was achieved.


2006 ◽  
Vol 20 (2) ◽  
pp. 620-624 ◽  
Author(s):  
Cristina M. Quintella ◽  
Ana Paula S. Musse ◽  
Martha T. P. O. Castro ◽  
J. C. Scaiano ◽  
Larisa Mikelsons ◽  
...  

Author(s):  
He Wang ◽  
Xiaohu Wang ◽  
Jiahai Huang ◽  
Jun Wang ◽  
Long Quan

The present study is focused on the construction of a well-performing pilot controlled proportional flow valve with internal displacement-flow feedback. A novel control strategy for the valve is proposed in which the flow rate through the valve is directly controlled. The linear mathematical model for the valve is established and a fuzzy proportional–integral–derivative (PID) controller is designed for the flow control. In order to obtain the flow rate used as feedback rapidly and accurately in real-time, back propagation neural network (BPNN) is employed to predict the flow rate through the valve with the pressure drop through the main orifice and main valve opening, and the predicted value is used as the feedback. Both simulation and experimental results show that the predicted value obtained by BPNN is reliable and available for the feedback. The proposed control strategy is effective with which the flow rate through the valve remains almost constant when the pressure drop through the main orifice increases and the valve can be applied to the conditions where the independence of flow rate and load is required. For the valve with the proposed control strategy, the nonlinearity is less than 5.3%, the hysteresis is less than 4.2%, and the bandwidth is about 16 Hz. The static and dynamic characteristics are reasonable and acceptable.


Electronics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 231 ◽  
Author(s):  
Panagiotis Kofinas ◽  
Anastasios I. Dounis

This paper proposes a hybrid Zeigler-Nichols (Z-N) fuzzy reinforcement learning MAS (Multi-Agent System) approach for online tuning of a Proportional Integral Derivative (PID) controller in order to control the flow rate of a desalination unit. The PID gains are set by the Z-N method and then are adapted online through the fuzzy Q-learning MAS. The fuzzy Q-learning is introduced in each agent in order to confront with the continuous state-action space. The global state of the MAS is defined by the value of the error and the derivative of error. The MAS consists of three agents and the output signal of each agent defines the percentage change of each gain. The increment or the reduction of each gain can be in the range of 0% to 100% of its initial value. The simulation results highlight the performance of the suggested hybrid control strategy through comparison with the conventional PID controller tuned by Z-N.


Lab on a Chip ◽  
2017 ◽  
Vol 17 (11) ◽  
pp. 2013-2021 ◽  
Author(s):  
Colm Delaney ◽  
Peter McCluskey ◽  
Simon Coleman ◽  
Jeffrey Whyte ◽  
Nigel Kent ◽  
...  

Precision control of flow using photoresponsive hydrogels within fluidic channels was demonstrated by applying a PID algorithm.


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