Pump Mechanical Seal Key Safety and Reliability Issues

Background: Valves are an important part of nuclear power plants and are the control equipment used in nuclear power plants. It can change the cross-section of the passage and the flow direction of the medium and has the functions of diversion, cutoff, overflow, and the like. Due to the earthquake, the valve leaks, which will cause a major nuclear accident, endangering people's lives and safety. Objective: The purpose of this study is to synthesize the existing valve devices, summarize and analyze the advantages and disadvantages of various devices from many literatures and patents, and solve some problems of existing valves. Methods: This article summarizes various patents of nuclear-grade valve devices and recent research progress. From the valve structure device, transmission device, a detection device, and finally to the valve test, the advantages and disadvantages of the valve are comprehensively analyzed. Results: By summarizing the characteristics of a large number of valve devices, and analyzing some problems existing in the valves, the outlook for the research and design of nuclear power valves was made, and the planning of the national nuclear power strategic goals and energy security were planned. Conclusion: Valve damage can cause serious safety accidents. The most common is valve leakage. Therefore, the safety and reliability of valves must be taken seriously. By improving the transmission of the valve, the problems of complicated valve structure and high cost are solved.

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Internal Leakage Fault Detection and Tolerant Control of Single-Rod Hydraulic Actuators

Mathematical Problems in Engineering ◽

10.1155/2014/345345 ◽

2014 ◽

Vol 2014 ◽

pp. 1-14 ◽

Cited By ~ 14

Author(s):

Jianyong Yao ◽

Guichao Yang ◽

Dawei Ma

Keyword(s):

Fault Detection ◽

Simple Structure ◽

Control Method ◽

Fault Tolerant ◽

Parameter Adaptation ◽

Servo Systems ◽

Hydraulic Actuators ◽

Quadratic Lyapunov Functions ◽

Safety And Reliability ◽

Hydraulic Servo

The integration of internal leakage fault detection and tolerant control for single-rod hydraulic actuators is present in this paper. Fault detection is a potential technique to provide efficient condition monitoring and/or preventive maintenance, and fault tolerant control is a critical method to improve the safety and reliability of hydraulic servo systems. Based on quadratic Lyapunov functions, a performance-oriented fault detection method is proposed, which has a simple structure and is prone to implement in practice. The main feature is that, when a prescribed performance index is satisfied (even a slight fault has occurred), there is no fault alarmed; otherwise (i.e., a severe fault has occurred), the fault is detected and then a fault tolerant controller is activated. The proposed tolerant controller, which is based on the parameter adaptive methodology, is also prone to realize, and the learning mechanism is simple since only the internal leakage is considered in parameter adaptation and thus the persistent exciting (PE) condition is easily satisfied. After the activation of the fault tolerant controller, the control performance is gradually recovered. Simulation results on a hydraulic servo system with both abrupt and incipient internal leakage fault demonstrate the effectiveness of the proposed fault detection and tolerant control method.

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Performance of an Advanced Intelligent Control Strategy in a Dynamic Positioning (DP) System Applied to a Semisubmersible Drilling Platform

Journal of Marine Science and Engineering ◽

10.3390/jmse9040399 ◽

2021 ◽

Vol 9 (4) ◽

pp. 399

Author(s):

Mohamad Alremeihi ◽

Rosemary Norman ◽

Kayvan Pazouki ◽

Arun Dev ◽

Musa Bashir

Keyword(s):

Oil And Gas ◽

Weather Conditions ◽

Dynamic Positioning ◽

System Failures ◽

Oil Drilling ◽

System A ◽

Advanced Control ◽

Safety And Reliability ◽

Drilling Operations ◽

Shallow Seas

Oil drilling and extraction platforms are currently being used in many offshore areas around the world. Whilst those operating in shallow seas are secured to the seabed, for deeper water operations, Dynamic Positioning (DP) is essential for the platforms to maintain their position within a safe zone. Operating DP requires intelligent and reliable control systems. Nearly all DP accidents have been caused by a combination of technical and human failures; however, according to the International Marine Contractors Association (IMCA) DP Incidents Analysis, DP control and thruster system failures have been the leading causes of incidents over the last ten years. This paper will investigate potential operational improvements for DP system accuracy by adding a Predictive Neural Network (PNN) control algorithm in the thruster allocation along with a nonlinear Proportional Integral derivative (PID) motion control system. A DP system’s performance on a drilling platform in oil and gas deep-water fields and subject to real weather conditions is simulated with these advanced control methods. The techniques are developed for enhancing the safety and reliability of DP operations to improve the positioning accuracy, which may allow faster response to a critical situation during DP drilling operations. The semisubmersible drilling platform’s simulation results using the PNN strategy show improved control of the platform’s positioning.

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PyroMEMS as Future Technological Building Blocks for Advanced Microenergetic Systems

Micromachines ◽

10.3390/mi12020118 ◽

2021 ◽

Vol 12 (2) ◽

pp. 118

Author(s):

Jean-Laurent Pouchairet ◽

Carole Rossi

Keyword(s):

Building Block ◽

Building Blocks ◽

Small Scale ◽

Technological Evolution ◽

Research Groups ◽

Function Block ◽

The Past ◽

New Methods ◽

Safety And Reliability ◽

Electronically Controllable

For the past two decades, many research groups have investigated new methods for reducing the size and cost of safe and arm-fire systems, while also improving their safety and reliability, through batch processing. Simultaneously, micro- and nanotechnology advancements regarding nanothermite materials have enabled the production of a key technological building block: pyrotechnical microsystems (pyroMEMS). This building block simply consists of microscale electric initiators with a thin thermite layer as the ignition charge. This microscale to millimeter-scale addressable pyroMEMS enables the integration of intelligence into centimeter-scale pyrotechnical systems. To illustrate this technological evolution, we hereby present the development of a smart infrared (IR) electronically controllable flare consisting of three distinct components: (1) a controllable pyrotechnical ejection block comprising three independently addressable small-scale propellers, all integrated into a one-piece molded and interconnected device, (2) a terminal function block comprising a structured IR pyrotechnical loaf coupled with a microinitiation stage integrating low-energy addressable pyroMEMS, and (3) a connected, autonomous, STANAG 4187 compliant, electronic sensor arming and firing block.

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Efficacy, safety, and reliability of surgery on the lumbar spine under general versus spinal anesthesia- an analysis of 64 cases

Journal of Clinical Orthopaedics and Trauma ◽

10.1016/j.jcot.2020.12.032 ◽

2021 ◽

Vol 16 ◽

pp. 176-181

Author(s):

Sharif Ahmed Jonayed ◽

Md Shah Alam ◽

Abdullah Al Mamun Choudhury ◽

Sohely Akter ◽

Shubhendu Chakraborty

Keyword(s):

Lumbar Spine ◽

Spinal Anesthesia ◽

Safety And Reliability

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