Transient Analysis of a High Pressure Seal Injection System Under Startup Conditions

2014 ◽  
Author(s):  
DeVon A. Washington ◽  
LeRoy N. Reiss
Keyword(s):  
Control Valve ◽  
Transient Behavior ◽  
Differential Pressure ◽  
Injection System ◽  
System Response ◽  
Primary Control ◽  
Fossil Plants ◽  
Actual System ◽  
Control Valves ◽  
In Series

This study examines the transient behavior of a seal injection system, for four boiler circulating water pumps, in an effort to optimize seal flush rates under startup conditions. During startup, seal injection supply water experiences a large increase in pressure, going from 1.8–26.2 MPa. This large increase in supply pressure presents a challenge in maintaining the desired differential pressure across the seals, and hence the optimum seal flush rate. Overshoot of the control valve position can result in starving the seals of seal water. Delayed responses expose the seals to excessively large differential pressures. The seal injection system was modeled using PIPENET™ Vision. The model consists of a detailed replica of the seal injection system pipe network. Initial and boundary conditions were obtained from plant DCS data and pump OEM specifications. A baseline model was developed and validated using actual system response data. Extended models considered two types of control systems, manual and differential pressure-control; as well as, control valves with various flow characteristics: linear and equal percentage. Additionally, a diffuser breakdown assembly and startup control valve were also introduced as control components into the model. Results show that the implantation of a diffuser breakdown assembly in series with the primary control valve (modified linear), in conjunction with automated controls produced a differential pressure of 436 kPa which was within the OEM specified range of differential pressures (345–690 kPa). A startup control valve used in series with the primary control valve also produced acceptable results (388 kPa). The proper design and operation of seal injection systems is vital to extending time between overhauls, thereby reducing maintenance costs. The use of the aforementioned control components in series with control valves is common for boiler feedwater regulation systems during startup; however, this is the first application known to the authors for pump seal injection systems in fossil plants. The results of the hydraulic simulation outlined in this study show this application is viable.

Exponential Tracking Control of a Hydraulic Proportional Directional Valve and Cylinder via Integrator Backstepping

2002 ◽  
Author(s):  
J. Chen ◽  
W. E. Dixon ◽  
J. R. Wagner ◽  
D. M. Dawson
Keyword(s):  
Pressure Drop ◽  
Tracking Control ◽  
Mechanical Load ◽  
Control Valve ◽  
Transient Behavior ◽  
Transportation Systems ◽  
System Response ◽  
Hydraulic Systems ◽  
Control Valves ◽  
Directional Control

Hydraulic systems are widely used in manufacturing processes and transportation systems where energy intensive operations are performed and “machine” control is vital. A variety of flow control products exist including manual directional control valves, proportional directional control valves, and servo-valves. The selection of a control valve actuation strategy is dependent on the system response requirements, permissible pressure drop, and hardware cost. Although high bandwidth servo-valves offer fast response times, the higher expense, susceptibility to debris, and pressure drop may be prohibitive. Thus, the question exists whether the economical proportional directional control valve’s performance can be sufficiently enhanced using nonlinear control strategies to begin approaching that of servo-valves. In this paper, exponential tracking control of a hydraulic cylinder and proportional directional control valve, with spool position feedback, is achieved for precise positioning of a mechanical load. An analytical and empirical mathematical model is developed which describes the transient behavior of the integrated components. A nonlinear backstepping control algorithm is designed to accommodate inherent system nonlinearities.

scholarly journals Design of direct acting differential pressure control valve test bench

2021 ◽  
Vol 327 ◽  
pp. 04002
Author(s):  
Ognyan Bekriev ◽  
Radoslav Asenov
Keyword(s):  
Test Bench ◽  
District Heating ◽  
Control Valve ◽  
Pressure Control ◽  
Differential Pressure ◽  
Heating Systems ◽  
Control Valves ◽  
District Heating Systems ◽  
Pressure Control Valve ◽  
Direct Acting

This article aims to acquaint readers with a designed test bench for direct acting differential pressure control valves. These control valves are used in district heating systems. The conformity of the construction of the test bench with the international standard IEC 60534-2-3:2015 is evaluate and the results of an experimental study of the control valve AVPB DN20 Kvs 6.3 PN16 are present.

scholarly journals Fault Tolerant Control Design for Feedwater System

2021 ◽  
Author(s):  
Mohammed Eltayb
Keyword(s):  
Controller Design ◽  
Fault Tolerant ◽  
Control Valve ◽  
Fault Tolerant Control ◽  
Control Valves ◽  
Hardware Failure ◽  
Water Storage Tank ◽  
Level Sensor ◽  
On Line ◽  
Hardware Failures

Fault tolerant control (FTC) is essential nowadays in the automation industry. It provides a means for higher equipment availability. Fault in dynamical systems can occur due to the deviation of the system parameters from the normal operating range. Alternatively, it can be a structural change from the normal situation of continuous operation such as the blocking of an actuator due to the mechanical stiction. In this research project, a fault tolerant controller is designed with Matlab Simulink for a feedwater system. The feedwater system components are modified to work under embedded controller design with FTC attached to it. Feedwater systems usually consist of a de-aerator or simply a water storage tank, feedwater pumps, control valves, piping and support fitting elements such as chock valves, anges, hoses and relief valves, beside instrumentation devices like level transmitters, flow transmitters, pressure regulators. The faults are injected separately for each device. Fault diagnostic is used to detect and identify the faults by Limit-checking method. Then a controller is reconfigured to take the action of correcting the hardware failures in the control valve, level sensor, and feedwater pump. The simulation results revealed that the redundant components can take over and handle the process operation when the fault occurs at the duty components. Level sensors are set to work in on-line mode, while the control valves are set to work in off-line mode, due to the mechanical parts movement. Setting the control valves in on-line mode reduces the probability of valve stiction and elongates the component availability. The results reveal the operation of feedwater system is not stopped when a hardware failure takes place in all feedwater system major components. Moreover, the disturbances are not considered in this research as there are many control techniques that can be used to handle the disturbance in a robust way.

Tackling the Methane Quandary: Curbing Emissions from Control Valves

2021 ◽  
Author(s):  
Andrea Pacini ◽  
Stefano Rossini
Keyword(s):  
Oil And Gas ◽  
Petroleum Industry ◽  
Field Tests ◽  
Control Valve ◽  
Methane Emissions ◽  
Fugitive Emissions ◽  
Fugitive Emission ◽  
Control Valves ◽  
One Year ◽  
The One

Abstract In the wake of Eni's strategy to curb fugitive emissions - in particular methane – an innovative control valve (Clarke Shutter Valve) has been deployed and tested in an Italian Eni facility. This shutter type valve is capable of reducing the fugitive emissions by more than 90%, as well as greatly curbing purchase costs, thanks to an innovative design in bonnet and regulating mechanism. In order to assess the real potentiality of the innovation, four Fisher globe valves and one Fisher V-ball were substituted with the Shutter Valves on different hydrocarbon streams of the Trecate facility (Piedmont), in particular on streams containing oil, gas and corrosive fluids. The valves were monitored for more than a year and fugitive emissions tests have been performed to detect and estimate methane leak rates. Since this represented a first deployment of this technology in Europe, a thorough analysis and technology validation of the valves has been performed. A successful installation and start-up were performed in 3 days by Eni's staff at in February of 2020. The valves were fully operational after the installation and to date no issues have been reported. In order to monitor the valves performances of flow control, continuous data collection on each valve has been implemented, and the analysis performed showed that all valves behave correctly as to Eni's standards. A fugitive emission test that has been performed at the end of 2020 with a certified portable FID/PID analyzer displayed that no methane emissions were detected from the valves. Lastly the one year and half long technology validation concluded that the Shutter Valves are a valid technology for curbing methane emissions from the Oil and Gas plants, and that suggested to qualify the company as Eni partner for control valves. This deployment and field tests, as well as the technological assessment performed by Eni's professionals showed the potentiality of this new type of valves in reducing the methane emissions from the petroleum industry. Understanding the potentiality of intrinsically carbon neutral technology is a crucial step for the mitigation of greenhouse gases emissions and towards the creation of a more environmentally friendly industry.

Scaling of Steam Turbine Control Valve Guidance Pins

2021 ◽  
Vol 58 (4) ◽  
pp. 216-223
Author(s):  
A. Neidel ◽  
E. Cagliyan ◽  
B. Fischer
Keyword(s):  
Steam Turbine ◽  
Control Valve ◽  
Oxidation Products ◽  
Control Valves ◽  
Common Scale

Abstract Severe scaling caused the guiding pin of two control valves of a smaller industrial steam turbine to seize which thus led to a malfunction. The customer sought clarification on whether the oxidation products are really common scale. This could be confirmed.

Implementation of Modified Field-Oriented Control Scheme for Improving the Fault Ride Through Ability of BDFIG System

2019 ◽  
Vol 29 (03) ◽  
pp. 2050040
Author(s):  
Maheswari Muthusamy ◽  
A. K. Parvathy
Keyword(s):  
Power Flow ◽  
Fuzzy Logic Controller ◽  
Fuzzy Controller ◽  
Digital Simulation ◽  
System Response ◽  
Field Oriented Control ◽  
Fault Ride Through ◽  
In Series ◽  
Doubly Fed ◽  
Static Compensator

This paper devises a design named brushless doubly fed induction generator (BDFIG) with a fault ride-through enhancement that employs upgraded field-oriented control (FOC) scheme. The DFIG is most suitable for wind energy conversion system (WECS) because it has an amicable establishment, economical operation and promising characteristics. A WECS based on two BDFIGs connected electrically in parallel and mechanically in series, excited by a three-phase inverter and controlled as variable speed, is described. For enhancing power quality and power flow capability, static compensator (STATCOM) has been incorporated in the proposed configuration. The comparative analysis on performance has been carried out with the existing proportional-integral (PI) controller and self-tuning fuzzy logic controller (STFLC) for the proposed configuration under varying wind speed. In this paper, the fuzzy controller is designed to adapt PI parameters Kp and Ki, in order to reduce at least some inherent characteristics (overshoot, response time, etc.) of the error between the reference and system response. The digital simulation results claim that the FLC-based controller can offer an attractive and feasible control for the proposed WECS integrating two BDFIGs.

scholarly journals Hardware-Simulator Development and Implementation for Hydraulic Turbine Generation Systems in a District Heating System

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 368 ◽  
Author(s):  
Sung-Soo Jeon ◽  
Young Jae Lee ◽  
Yeongsu Bak ◽  
Kyo-Beum Lee
Keyword(s):  
Control Strategies ◽  
District Heating ◽  
Control Valve ◽  
Electrical Energy ◽  
Heating System ◽  
Hydraulic Turbine ◽  
Pressure Control ◽  
Differential Pressure ◽  
District Heating System ◽  
Pressure Control Valve

This paper presents not only a hardware-simulator development for hydraulic turbine generation systems (HTGS) in a district heating system (DHS) but also its control strategies and sequence. Generally, a DHS uses a differential pressure control valve (DPCV) to supply high-pressure–high-temperature fluids for customers depending on distance. However, long-term exposure of the DPCV to fluids increases the probability of cavitation and leads to heat loss in an event of cavitation. Therefore, a HTGS was introduced to solve this problem. It performs differential pressure control of the fluids, replaces the DPCV, and converts excess energy wasted by the DPCV to electrical energy. In this paper, the development of a hardware-simulator for HTGSs with a back-to-back converter, which uses two-level topologies, is proposed; moreover, control strategies and sequence used in this design are presented. The performance and validity of the proposed hardware-simulator and its control strategies are demonstrated by experimental results.

Intelligent Fault Diagnosis of the Control Valve with High Flow Rate

2010 ◽  
Vol 455 ◽  
pp. 232-236
Author(s):  
Yue Rong Zhang ◽  
Yong Wang
Keyword(s):  
Fault Diagnosis ◽  
Flow Rate ◽  
Chemical Engineering ◽  
Control Valve ◽  
Electricity Industry ◽  
High Flow ◽  
Nuclear Industry ◽  
High Flow Rate ◽  
Intelligent Fault Diagnosis ◽  
Control Valves

Control valves are the crucial assembly, which controls the flow of medium in fluid machines. Control valves play an important role in electricity industry, nuclear industry, and chemical engineering. The technology of fault diagnosis is applied to the fault detection and fault diagnosis of the control valve with high flow rate for the sake of economic development and safety. This paper presents results of a study on classification and mechanism of the common faults of control valves in connection with the structure of the valve applied to the circle-electricity industry. We analyzed the principles and characteristics of different diagnosis methods, discussed the mechanism of different faults of the valve. Furthermore, we investigated the diagnosis method that is suitable for different faults of the valve and the pivotal technique with which intelligent fault diagnosis (IFD) can be realized successfully. In addition, the route and the plan of the study on IFD of the control valve with high flow rate is suggested to develop a system of intelligent fault diagnosis and detection (IFDD) for the control valve.

Optimal Pump Speed Control in a Chilled Water System

2007 ◽  
Author(s):  
Bin Zheng ◽  
Mingsheng Liu
Keyword(s):  
Water System ◽  
Pump Energy ◽  
Control Valve ◽  
Speed Control ◽  
Differential Pressure ◽  
Pump Efficiency ◽  
Pump Speed ◽  
Chilled Water ◽  
Pump Head ◽  
Chilled Water System

Traditionally, chilled water pump speed is modulated to maintain the water loop differential pressure set point and the control valve at the air handling unit (AHU) is modulated to maintain the supply air temperature. This paper introduces a new VFD pump speed control algorithm, optimal pump head control strategy. The algorithm focuses on minimizing the water loop differential pressure in order to reduce the overall pump energy consumption. The new algorithm is implemented in a real chilled water system. The pump power consumption is compared between the traditional algorithm and new algorithm. The implementing result demonstrates that the new algorithm results in improved pump efficiency, reduced pump head and pump speed and remarkable energy savings.

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