The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Andrea Cortinovis - One of the best experts on this subject based on the ideXlab platform.
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a distributed feasible side convergent modifier adaptation scheme for interconnected systems with application to Gas compressor stations
Computers & Chemical Engineering, 2018Co-Authors: Predrag Milosavljevic, Andrea Cortinovis, Rene Schneider, Timm Faulwasser, Dominique BonvinAbstract:Abstract Recently, a feasible-side globally convergent modifier-adaptation scheme has been proposed for the real-time optimization of uncertain systems. We show that this scheme is related to proximal-gradient algorithms in numerical optimization and we exploit this relationship to analyze its convergence in the case of inexact gradient information. We also make use of this relationship to propose a novel distributed modifier-adaptation algorithm for interconnected systems that uses a coordinator and knowledge of the interconnection topology. We then prove its feasible-side convergence to plant optimality. In addition, our distributed algorithm ensures confidentiality of local models and data. We finally demonstrate the applicability and effectiveness of this algorithm on a load-sharing optimization case study for serially connected Gas Compressors.
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online performance tracking and load sharing optimization for parallel operation of Gas Compressors
Computers & Chemical Engineering, 2016Co-Authors: Andrea Cortinovis, Mehmet Mercangoz, Matteo Zovadelli, Diego Pareschi, Antonio De Marco, S BittantiAbstract:Abstract Compressor stations on natural Gas pipelines are typically composed of multiple parallel Compressors for operational flexibility. The aim of load sharing optimization is to operate the compressor units of a Gas compression station in an energy efficient way while satisfying the varying Gas demand. This paper presents a problem formulation for compressor load sharing optimization, as well as a novel method to track the performance characteristics of Gas Compressors using thermodynamic models and historical operating data. An implementation of the proposed algorithm together with a dedicated case study concerning a station with 10 Gas turbine driven compressor units are presented. The optimization results, which are based on simulations with actual operating data spanning over a 1 year duration, indicate an annual fuel saving potential of over 5% potentially leading to improved profitability and to a significant reduction of CO2 emissions from the Gas turbine drivers.
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dynamic time to surge computation for electric driven Gas Compressors during voltage dips
IFAC-PapersOnLine, 2016Co-Authors: Andrea Cortinovis, Mehmet Mercangoz, Tor Olav Stava, Sture Van De Moortel, Erling LundeAbstract:Abstract This paper investigates the influence of voltage dips on large electric driven Gas Compressors (EDC) considering a typical application in the oil and Gas industry. Voltage or power dips are electric disturbances encountered in EDC which are mainly caused by faults in the electrical grid and might last for durations up to 150 ms. For Gas compression applications, the loss of driver torque often puts the Gas compression process at risk of surge conditions, which is a safety critical constraint. The critical nature of the present problem and the fast dynamics involved, pose challenging requirements for the control and safety systems of the Gas compressor and the variable-speed drive system. The main focus of the present paper is the dynamic computation of the time to surge using online information of the estimated motor torque and a process model to predict the future behavior of the compression system. The time to surge can then be used for ride-through or shut-down decisions of the complete system, as well as for manipulating safety valves, e.g. the anti-surge valve. The fulfillment of strict real-time requirements and their direct implications on the complexity of the chosen prediction model and the implementation of the algorithm on an embedded system are also addressed in this article. As an industrial case study, the algorithm is applied to a voltage dip situation using high fidelity simulation data of a compression station.
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experimental evaluation of mpc based anti surge and process control for electric driven centrifugal Gas Compressors
Journal of Process Control, 2015Co-Authors: Andrea Cortinovis, Hans Joachim Ferreau, Daniel Lewandowski, Mehmet MercangozAbstract:Abstract The present work concerns model predictive control (MPC) of centrifugal Gas Compressors and describes the development of an MPC application for the tasks of anti-surge and process control. More specifically, the MPC formulation focuses on the question of how the transient manipulation of driver torque can be used to improve the performance of anti-surge and process control. For the purpose of testing and validating the proposed control algorithm, an experimental compressor test rig is presented, which is designed to mimic a typical centrifugal compressor application in the oil and Gas industry. Modeling and parameter identification of the experimental setup is followed by the realization of the MPC solution on an embedded system to comply with the stringent real-time requirements for anti-surge control. Testing is performed with experiments using suction and discharge side disturbances, which are created by rapid valve closures. For comparison the same tests are repeated with conventional control approaches. The test results indicate improvements in maintaining the distance to surge by up to 11%, while at the same time reducing the process control settling time by up to 50%.
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online adaptation of performance maps for centrifugal Gas Compressors
European Control Conference, 2014Co-Authors: Andrea Cortinovis, Mehmet Mercangoz, Matteo Zovadelli, Diego Pareschi, Antonio De Marco, S BittantiAbstract:This paper investigates the adaptation of different performance maps of centrifugal Compressors driven by dualshaft Gas turbines during operation. First the estimation of compressor, Gas turbine and combined efficiency are considered. Obtaining performance maps is mainly based on fitting an empirical model to the history of past data together with the understanding of how much new information is contained in newly collected data samples. This amounts to solving a leastsquares problem which is formulated as a quadratic program using various constraints. Comparing the actual efficiency to the predicted efficiency by evaluating the previously fitted model, the algorithm decides whether the actual model is accurate enough or a model update is needed. The necessity of having an online model update comes from the fact that the efficiency maps can change due to several factors such as fouling. The algorithm is tested using industrial data from a Gas compression station with five Gas turbine-driven Compressors. The results show the need of online adaptation and that it is possible to accurately predict the different efficiencies using the presented method without excessive model updates. The access to online updated performance maps allows to understand how well the system is performing and gives the opportunity to monitor the efficiency of a specific unit. It is possible to use the adapted performance maps for load sharing optimization with timevarying optimization models.
Mehmet Mercangoz - One of the best experts on this subject based on the ideXlab platform.
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online performance tracking and load sharing optimization for parallel operation of Gas Compressors
Computers & Chemical Engineering, 2016Co-Authors: Andrea Cortinovis, Mehmet Mercangoz, Matteo Zovadelli, Diego Pareschi, Antonio De Marco, S BittantiAbstract:Abstract Compressor stations on natural Gas pipelines are typically composed of multiple parallel Compressors for operational flexibility. The aim of load sharing optimization is to operate the compressor units of a Gas compression station in an energy efficient way while satisfying the varying Gas demand. This paper presents a problem formulation for compressor load sharing optimization, as well as a novel method to track the performance characteristics of Gas Compressors using thermodynamic models and historical operating data. An implementation of the proposed algorithm together with a dedicated case study concerning a station with 10 Gas turbine driven compressor units are presented. The optimization results, which are based on simulations with actual operating data spanning over a 1 year duration, indicate an annual fuel saving potential of over 5% potentially leading to improved profitability and to a significant reduction of CO2 emissions from the Gas turbine drivers.
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dynamic time to surge computation for electric driven Gas Compressors during voltage dips
IFAC-PapersOnLine, 2016Co-Authors: Andrea Cortinovis, Mehmet Mercangoz, Tor Olav Stava, Sture Van De Moortel, Erling LundeAbstract:Abstract This paper investigates the influence of voltage dips on large electric driven Gas Compressors (EDC) considering a typical application in the oil and Gas industry. Voltage or power dips are electric disturbances encountered in EDC which are mainly caused by faults in the electrical grid and might last for durations up to 150 ms. For Gas compression applications, the loss of driver torque often puts the Gas compression process at risk of surge conditions, which is a safety critical constraint. The critical nature of the present problem and the fast dynamics involved, pose challenging requirements for the control and safety systems of the Gas compressor and the variable-speed drive system. The main focus of the present paper is the dynamic computation of the time to surge using online information of the estimated motor torque and a process model to predict the future behavior of the compression system. The time to surge can then be used for ride-through or shut-down decisions of the complete system, as well as for manipulating safety valves, e.g. the anti-surge valve. The fulfillment of strict real-time requirements and their direct implications on the complexity of the chosen prediction model and the implementation of the algorithm on an embedded system are also addressed in this article. As an industrial case study, the algorithm is applied to a voltage dip situation using high fidelity simulation data of a compression station.
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experimental evaluation of mpc based anti surge and process control for electric driven centrifugal Gas Compressors
Journal of Process Control, 2015Co-Authors: Andrea Cortinovis, Hans Joachim Ferreau, Daniel Lewandowski, Mehmet MercangozAbstract:Abstract The present work concerns model predictive control (MPC) of centrifugal Gas Compressors and describes the development of an MPC application for the tasks of anti-surge and process control. More specifically, the MPC formulation focuses on the question of how the transient manipulation of driver torque can be used to improve the performance of anti-surge and process control. For the purpose of testing and validating the proposed control algorithm, an experimental compressor test rig is presented, which is designed to mimic a typical centrifugal compressor application in the oil and Gas industry. Modeling and parameter identification of the experimental setup is followed by the realization of the MPC solution on an embedded system to comply with the stringent real-time requirements for anti-surge control. Testing is performed with experiments using suction and discharge side disturbances, which are created by rapid valve closures. For comparison the same tests are repeated with conventional control approaches. The test results indicate improvements in maintaining the distance to surge by up to 11%, while at the same time reducing the process control settling time by up to 50%.
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online adaptation of performance maps for centrifugal Gas Compressors
European Control Conference, 2014Co-Authors: Andrea Cortinovis, Mehmet Mercangoz, Matteo Zovadelli, Diego Pareschi, Antonio De Marco, S BittantiAbstract:This paper investigates the adaptation of different performance maps of centrifugal Compressors driven by dualshaft Gas turbines during operation. First the estimation of compressor, Gas turbine and combined efficiency are considered. Obtaining performance maps is mainly based on fitting an empirical model to the history of past data together with the understanding of how much new information is contained in newly collected data samples. This amounts to solving a leastsquares problem which is formulated as a quadratic program using various constraints. Comparing the actual efficiency to the predicted efficiency by evaluating the previously fitted model, the algorithm decides whether the actual model is accurate enough or a model update is needed. The necessity of having an online model update comes from the fact that the efficiency maps can change due to several factors such as fouling. The algorithm is tested using industrial data from a Gas compression station with five Gas turbine-driven Compressors. The results show the need of online adaptation and that it is possible to accurately predict the different efficiencies using the presented method without excessive model updates. The access to online updated performance maps allows to understand how well the system is performing and gives the opportunity to monitor the efficiency of a specific unit. It is possible to use the adapted performance maps for load sharing optimization with timevarying optimization models.
Shubhendu Kumar Sarangi - One of the best experts on this subject based on the ideXlab platform.
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mathematical modeling of the working cycle of oil injected rotary twin screw compressor
Applied Thermal Engineering, 2007Co-Authors: N Seshaiah, R K Sahoo, S.k. Ghosh, Shubhendu Kumar SarangiAbstract:Oil injected twin-screw air and Gas Compressors are widely used for medium pressure applications in many industries. Low cost air Compressors can be adopted for compression of helium and special Gases, leading to significant cost saving. Mathematical analysis of oil injected twin-screw compressor is carried out on the basis of the laws of perfect Gas and standard thermodynamic relations. Heat transfer coefficient required for computer simulation is experimentally obtained and used in performance prediction, when the working medium being air or helium. A mathematical model has been developed for calculating the compressor performance and for validating the results with experimental data. The flow coefficients required for numerical simulation to calculate leakage flow rates are obtained from efficiency verses clearance curves. Effect of some of the compressor operating and design parameters on power and volumetric efficiencies have been analyzed and presented.
N Seshaiah - One of the best experts on this subject based on the ideXlab platform.
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mathematical modeling of the working cycle of oil injected rotary twin screw compressor
Applied Thermal Engineering, 2007Co-Authors: N Seshaiah, R K Sahoo, S.k. Ghosh, Shubhendu Kumar SarangiAbstract:Oil injected twin-screw air and Gas Compressors are widely used for medium pressure applications in many industries. Low cost air Compressors can be adopted for compression of helium and special Gases, leading to significant cost saving. Mathematical analysis of oil injected twin-screw compressor is carried out on the basis of the laws of perfect Gas and standard thermodynamic relations. Heat transfer coefficient required for computer simulation is experimentally obtained and used in performance prediction, when the working medium being air or helium. A mathematical model has been developed for calculating the compressor performance and for validating the results with experimental data. The flow coefficients required for numerical simulation to calculate leakage flow rates are obtained from efficiency verses clearance curves. Effect of some of the compressor operating and design parameters on power and volumetric efficiencies have been analyzed and presented.
S.k. Ghosh - One of the best experts on this subject based on the ideXlab platform.
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mathematical modeling of the working cycle of oil injected rotary twin screw compressor
Applied Thermal Engineering, 2007Co-Authors: N Seshaiah, R K Sahoo, S.k. Ghosh, Shubhendu Kumar SarangiAbstract:Oil injected twin-screw air and Gas Compressors are widely used for medium pressure applications in many industries. Low cost air Compressors can be adopted for compression of helium and special Gases, leading to significant cost saving. Mathematical analysis of oil injected twin-screw compressor is carried out on the basis of the laws of perfect Gas and standard thermodynamic relations. Heat transfer coefficient required for computer simulation is experimentally obtained and used in performance prediction, when the working medium being air or helium. A mathematical model has been developed for calculating the compressor performance and for validating the results with experimental data. The flow coefficients required for numerical simulation to calculate leakage flow rates are obtained from efficiency verses clearance curves. Effect of some of the compressor operating and design parameters on power and volumetric efficiencies have been analyzed and presented.
