The Experts below are selected from a list of 46050 Experts worldwide ranked by ideXlab platform
Valentina Colla - One of the best experts on this subject based on the ideXlab platform.
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steam turbine Control Valve and actuation system modeling for dynamics analysis
Energy Procedia, 2017Co-Authors: M Pondini, A Signorini, Valentina CollaAbstract:Abstract The paper describes a study conducted on Steam Turbine Control Valve and actuation systems, which rule the machine final power production and rotational speed. A dynamic model developed in the Matlab/Simulink environment is proposed to support the analysis of the operational stability of the hydro-mechanical system as well as the failure modes that it may face during operation. The model was validated through specific field tests conducted on the actuation system at a cogeneration plant in Nuovo Pignone, Florence. The proposed work also underlines the requirements that new actuation technologies should fulfil in order to meet Control Valve system performance criteria.
M Pondini - One of the best experts on this subject based on the ideXlab platform.
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steam turbine Control Valve and actuation system modeling for dynamics analysis
Energy Procedia, 2017Co-Authors: M Pondini, A Signorini, Valentina CollaAbstract:Abstract The paper describes a study conducted on Steam Turbine Control Valve and actuation systems, which rule the machine final power production and rotational speed. A dynamic model developed in the Matlab/Simulink environment is proposed to support the analysis of the operational stability of the hydro-mechanical system as well as the failure modes that it may face during operation. The model was validated through specific field tests conducted on the actuation system at a cogeneration plant in Nuovo Pignone, Florence. The proposed work also underlines the requirements that new actuation technologies should fulfil in order to meet Control Valve system performance criteria.
A Signorini - One of the best experts on this subject based on the ideXlab platform.
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steam turbine Control Valve and actuation system modeling for dynamics analysis
Energy Procedia, 2017Co-Authors: M Pondini, A Signorini, Valentina CollaAbstract:Abstract The paper describes a study conducted on Steam Turbine Control Valve and actuation systems, which rule the machine final power production and rotational speed. A dynamic model developed in the Matlab/Simulink environment is proposed to support the analysis of the operational stability of the hydro-mechanical system as well as the failure modes that it may face during operation. The model was validated through specific field tests conducted on the actuation system at a cogeneration plant in Nuovo Pignone, Florence. The proposed work also underlines the requirements that new actuation technologies should fulfil in order to meet Control Valve system performance criteria.
W L Cleghorn - One of the best experts on this subject based on the ideXlab platform.
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self excited vibration of a Control Valve due to fluid structure interaction
Journal of Fluids and Structures, 2002Co-Authors: A Misra, Kamran Behdinan, W L CleghornAbstract:Abstract In this paper, the mechanism causing self-excited vibration of a piping system is determined using a dynamic model which couples the hydraulics of a piping system with the structural motion of an air-operated, plug-type automatic Control Valve. In the dynamic model developed, the structural system consists of a Valve spring–mass system, while the fluid system consists of a pump, upstream piping, Control Valve and downstream piping. The coupling between the structural and the fluid systems at the Control Valve is obtained by making the fluid flow coefficient at the Control Valve to be a function of Valve plug displacement, and by making the Valve plug displacement to be a function of fluid pressure and velocity. The dynamic model presented in this paper, for the first time, considers compressibility of the fluid in both the upstream and downstream piping. The dynamic model presented was benchmarked against in situ measurements. The data used for the benchmarking are provided in the paper. A review of the numerical results obtained indicates that the self-excited vibration occurs due to the coincidence of water hammer, acoustic feedback in the downstream piping, high acoustic resistance at the Control Valve, and negative hydraulic stiffness at the Control Valve.
Minsoo Kim - One of the best experts on this subject based on the ideXlab platform.
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Enhancement of heat pump performance by pulsation of refrigerant flow using a solenoid-driven Control Valve
International Journal of Refrigeration-revue Internationale Du Froid, 2012Co-Authors: Chul Woo Roh, Minsoo KimAbstract:Abstract The heating performance of an R410A heat pump system can be enhanced by a pulsatile refrigerant flow in a heat pump cycle. To generate the pulsatile refrigerant flow, a Control Valve was installed in parallel with the expansion Valve located between the outlet of the condenser and the inlet of the evaporator in this system. Intermittent 200-ms openings of the Control Valve improved the heating performance because of two factors: the ‘pulsation effect’ that enhanced heat transfer and the ‘pushing effect’ that elevated the condensing pressure and increased overall mass flow rate. Heating capacity and COP (coefficient of performance) were increased by 4% and 3.2%, respectively, when the Control Valve operated at 0.005 Hz and 0.1% duty. In phenomenological view, two-phase invasion is considered when the Control Valve is operated.
