Change in Distillation Column Control Philosophy Using Dynamic Simulation

2019 ◽  
Vol 15 (3) ◽  
Author(s):  
Kanubhai Parmar ◽  
Sukanta Dash ◽  
Sunil Patil ◽  
Garimella Padmavathi
Keyword(s):  
Steady State ◽  
Dynamic Simulation ◽  
Operating Parameter ◽  
Simulation Models ◽  
Composition Control ◽  
Aspen Hysys ◽  
Steady State Model ◽  
Process Behavior ◽  
Steady State Simulation ◽  
Bottom Product

AbstractAt condensate stripper of a cracker plant with design control philosophy for composition control pant was facing operational difficulty. Due to disturbance in operating parameter column was becoming unstable and product was getting offspec w.r.t. desired purity. One of the applications of dynamic simulation is to troubleshoot the challenges related to control philosophy in practical application. Since steady-state simulation models cannot predict behavior with respect to time, initially steady state model and finally a dynamic model was developed in Aspen HYSYS. The model is used to study the process behavior for existing control philosophy and proposed philosophy. To avoid column puncture and without waiting for plant shut down the existing Temperature Indicator (TI) considered as Temperature Indicator Controller (TIC) for the study. A new control philosophy was developed based on the response of variables after disturbances in feed rate and composition. The revised control philosophy has been implemented and is now working satisfactorily, providing stabilized operation of the column with consistent bottom product quality. This has helped to reduce the loss of C2s in the bottom stream by about 700 ppm, for savings of about $100,000 USD per year.

Sizing Wet-Gas Pipelines and Slug Catchers With Steady-State Multiphase Flow Simulations

1998 ◽  
Vol 120 (2) ◽  
pp. 106-110 ◽  
Author(s):  
J. J. Xiao ◽  
G. Shoup
Keyword(s):  
Steady State ◽  
Multiphase Flow ◽  
Simulation Models ◽  
Gas Pipelines ◽  
Flow Simulations ◽  
Wet Gas ◽  
Starting Point ◽  
Operational Information ◽  
Exit Speed ◽  
Steady State Simulation

The design of wet-gas pipelines and slug catchers requires multiphase flow simulations, both steady-state and transient. However, steady-state simulation is often inadequately conducted and its potential not fully utilized. This paper shows how mechanistic steady-state simulation models can be used to obtain not only pressure drop, liquid holdup and flow regime, but also to extract important operational information such as pig transit time, pig exit speed, liquid buildup rate behind the pig, and the time for the pipeline to return to a steady-state after pigging. A well-designed set of steady-state simulations helps to determine pipeline size, slug catcher size, and pigging frequency. It also serves as a starting point for subsequent transient multiphase flow simulations.

Control Performance Analysis of SR S/G System Based on FEM

2012 ◽  
Vol 246-247 ◽  
pp. 801-805
Author(s):  
Shou Jun Song ◽  
Man Zhang ◽  
Wen Jie Liu ◽  
Ze Xiu Han
Keyword(s):  
Steady State ◽  
Dynamic Simulation ◽  
Performance Optimization ◽  
Parametric Method ◽  
Strong Nonlinearity ◽  
Control Performance ◽  
Switched Reluctance ◽  
Reluctance Machine ◽  
Torque Curve ◽  
Steady State Simulation

Switched reluctance machine (SRM) has many outstanding advantages, and can be widely used in many electromechanical applications. However, it’s relatively difficult to analyze the control performance of SRM due to strong nonlinearity of the electromagnetic field. In this paper, the performance of SRM is analyzed by finite element method (FEM). Firstly, the simulation model of a 4-phase 8/6 pole SRM is built, and then the steady-state and dynamic simulation are carried out. In steady-state simulation, the magnetization and torque characteristics are obtained by parametric method. In dynamic simulation, the performance, include current and torque curve, under both motoring and generating mode are given. The simulation and analysis results are useful for performance optimization of SRM.

Dynamic Simulation on Secondary System of Nuclear Power Plant

2012 ◽  
Vol 591-593 ◽  
pp. 620-625 ◽  
Author(s):  
Rui Yu ◽  
Shi Wei Yao ◽  
Chun Guo Wang
Keyword(s):  
Steady State ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Dynamic Simulation ◽  
Nuclear Power ◽  
Large Scale ◽  
Simulation Models ◽  
Secondary System ◽  
Actual System ◽  
Moisture Separator

The secondary system of Qinshan phase I nuclear power plant is simulated in this study. According to the characteristics of the JTopmeret model, the system is divided into six parts for modeling, which are the deaerator, the high pressure (HP) turbine, the low pressure (LP) turbine, the moisture separator reheater (MSR), the condensate system, and the feedwater system. All parts are built as the graphic automatic models in JTopmeret and debugged on the large-scale simulation platform GSE to complete the steady-state and dynamic simulation of the models. The results show that the steady-state and dynamic processes of the models are consistent with the characteristics of the actual system. It verifies the correctness of the simulation models. Thus, this research is able to provide guidance for the operation analysis and the equipment debugging of the secondary system of the nuclear power plant.

Steady-State Simulation of the Counter Current Liquid-Liquid Ex-Traction: Trimetozine Synthesis as a Case Study

2019 ◽  
Author(s):  
Zied Hosni ◽  
Ian Houson ◽  
Brahim Benyahia ◽  
Alastair Florence
Keyword(s):  
Steady State ◽  
Partition Coefficients ◽  
Industrial Process ◽  
Liquid Extraction ◽  
Liquid Liquid Extraction ◽  
Steady State Model ◽  
Liquid Model ◽  
Steady State Simulation ◽  
Counter Current

The countercurrent liquid-liquid extraction is a crucial step in industrial process to purify and extract a compound of inter-ests for its impurities. This step requires generally challenging and time-consuming optimisation of numerous factors that affect the overall yield of extraction and the energy needed. The simulation of this process has been investigated in this pa-per using a Non-Random Two Liquid model implemented as a thermodynamic method in Aspen. The outcome of this model enables the evaluation of the partition coefficients of the different analytes of a mixtures at the different compart-ments of extraction platform. In addition, this steady-state model allows a more straightforward optimisation of the factors that drive the performance of extraction.

scholarly journals Steady-State Simulation of the Counter Current Liquid-Liquid Ex-Traction: Trimetozine Synthesis as a Case Study

2019 ◽  
Author(s):  
Zied Hosni ◽  
Ian Houson ◽  
Brahim Benyahia ◽  
Alastair Florence
Keyword(s):  
Steady State ◽  
Partition Coefficients ◽  
Industrial Process ◽  
Liquid Extraction ◽  
Liquid Liquid Extraction ◽  
Steady State Model ◽  
Liquid Model ◽  
Steady State Simulation ◽  
Counter Current

The countercurrent liquid-liquid extraction is a crucial step in industrial process to purify and extract a compound of inter-ests for its impurities. This step requires generally challenging and time-consuming optimisation of numerous factors that affect the overall yield of extraction and the energy needed. The simulation of this process has been investigated in this pa-per using a Non-Random Two Liquid model implemented as a thermodynamic method in Aspen. The outcome of this model enables the evaluation of the partition coefficients of the different analytes of a mixtures at the different compart-ments of extraction platform. In addition, this steady-state model allows a more straightforward optimisation of the factors that drive the performance of extraction.

scholarly journals Implementation of a Single Effect Absorption LiBr-H2O Refrigeration Chiller by using Thermodynamic Modeling and Steady State Simulation

2019 ◽  
Vol 8 (2) ◽  
pp. 2900-2906
Keyword(s):  
Steady State ◽  
Heat Exchanger ◽  
Heat Source ◽  
Operating Parameter ◽  
High Heat ◽  
Cycle Performance ◽  
Refrigeration System ◽  
Single Effect ◽  
Steady State Simulation ◽  
The Impact

The objective of this research paper is to present steady state simulation model and EES program for design and thermodynamic analysis is used to predict the performance of single effect vapor absorption chiller. The working condition of steam is entering and exit to the generator. At that point, the program gives the thermodynamic properties of all purposes of the state, for example, design information each heat exchangers in the cycle and the overall performance of the cycle. The outcome is from EES program is utilized to contemplate the impact of structure parameters on cycle performance. In the conventional absorption refrigeration system dilute solution of LiBr is directly goes to the generator at inlet of generator in this type high heat source is required and increasing the area of the generator. In this paper is to present incorporation of heat reclaimer in the solution heat exchanger and the generator. The addition of one heat exchanger with increasing COP as well as reduced heat source and heat transfer area in the generator. This program gives the operating parameter at all state points, design value of all heat exchanger and design performance of the system. The refrigeration capacity of the system is 100TR. To check the performance of system by using changing flow rate of heat source, heat exchanger effectiveness. The output of this program and simulation results use for the sizing of new refrigeration system.

scholarly journals Steady State Simulation of Plastic Pyrolysis Process using Aspen Hysys V9 Simulator

2019 ◽  
Vol 8 (4) ◽  
pp. 2206-2211 ◽  
Keyword(s):  
Steady State ◽  
Liquid Fuel ◽  
Liquid Fraction ◽  
Scale Up ◽  
Pyrolysis Process ◽  
Aspen Hysys ◽  
Plastic Wastes ◽  
Poly Ethylene ◽  
Steady State Simulation ◽  
Poly Propylene

The present study was carrying out the simulation of plastic pyrolysis process modelled for the conversion of petroleum product from plastic wastes such as Poly-Styrene (PS), PolyEthylene (PE), Poly-Propylene (PP) and Poly-Styrene (PS) with the aid of Aspen Hysys V9 simulator. Aspen Hysys simulator was used to develop the steady state model and to simulate the pyrolysis process with the above mentioned plastic wastes. PengRobinson thermodynamics model was employed as a fluid package of this simulation. The process converts waste plastic to fuel, which was taking places in two stages in an Aspen Hysys Simulation Environment such as i) A conversion of plastic wastes into Vapour-Liquid Fraction (VLF) with small quantity of char residue using conversion reactor (Pyrolytic Reactor) and ii) Separation of produced Vapour-Liquid Fraction to pyro gases and liquid fuel with the help of water tube Condenser. The obtained results demonstrated that, a conversion of Poly-Styrene (PS) into liquid fuel is up to 88.7% was optimum than other plastics Poly-Ethylene (PE) 81.95% and Poly-Propylene (PP) 83.54 %. The simulated model can help an interested to researcher in knowing expected products and their individual component for better understanding and scale-up studies.

scholarly journals Generalizing WDN simulation models to variable tank levels

2011 ◽  
Vol 14 (3) ◽  
pp. 562-573 ◽  
Author(s):  
Orazio Giustolisi ◽  
Luigi Berardi ◽  
Daniele Laucelli
Keyword(s):  
Steady State ◽  
Mass Balance ◽  
Water Distribution ◽  
Extended Period ◽  
Water Distribution Network ◽  
Simulation Models ◽  
Gradient Algorithm ◽  
Initial State ◽  
Cross Sectional ◽  
Steady State Simulation

In water distribution network (WDN) steady-state modelling, tanks and reservoirs are modelled as nodes with known heads. As a result, the tank levels are upgraded after every steady-state simulation (snapshot) using external mass balance equations in extended period simulation (EPS). This approach can give rise to numerical instabilities, especially when tanks are in close proximity. In order to obtain a stable EPS model, an unsteady formulation of the WDN model has recently introduced. This work presents an extension of the steady-state WDN model, both for demand-driven and pressure-driven analyses, allowing the direct prediction of head variation of tank nodes with respect to an initial state. Head variations at those nodes are introduced as internal unknowns in the model, the variation of tank levels can be analyzed in the single steady-state simulation and EPS can be performed as a sequence of simulations without the need for external mass balances. The extension of mass balance at tank nodes allows the analysis of some technically relevant demand components. Furthermore, inlet and outlet head losses at tank nodes are introduced and large cross-sectional tank areas are allowed by the model and reservoirs become a special case of tanks. The solution algorithm is the generalized-global gradient algorithm (G-GGA), although the proposed WDN model generalization is universal.

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