模糊逻辑控制在核动力系统中的应用和问题探讨

模糊逻辑控制(FLC)在核动力系统中的应用研究表明、FLC对核动力系统的智能化和全自动化控制而言,是一种有效而可行的先进控制方法。本文对此方面的研究成果进行了全面回顾和总结,并探讨了FLC应用研究和实践中需要重点解决的问题。     

Progress of microwave diagnostics development on the HL-2A tokamak

Sets of powerful microwave diagnostic systems have been developed on the HL-2A tokamak, including 18 subsystems with high spatial and temporal resolutions. These systems have been applied in the HL-2A tokamak experiments to investigate the core plasma transport, turbulence, MHD, energetic particle physics and so on. In this paper, the microwave diagnostics and their applications are reviewed. Some new technologies, including GHz sampling digital correlation electron cyclotron emission (DCECE), multi-channel correlation reflectometers, and solid state terahertz interferometers, are also presented in the paper.     

A mathematical model of a control rod drop

A mathematical model of a control rod drop for a pressurized water reactor is presented. A hybrid computer program is used to solve the non-linear differential equations which describe the model. The computer solution is briefly described. The rod drop time computed by using the model is compared with available data from experimental results for a rack and pinion control system. Additional applications of the mathematical model are described and presented.     

可用于核物理监控系统的microC/OS-Ⅱ片上系统的研究

论述了一种基于FPGA和实时操作系统microC/OS-Ⅱ、适用于核物理数据检测和实验控制的片上可编程系统SOPC(System On a Programmable Chip)的设计,并在altera-stratix-Ⅱ2S60f1020c3芯片内获得实现.该片上可编程系统的硬件处理器和实时操作系统都可根据需求裁剪、重配置.     

An analytical method for modeling two-phase gravity-driven drainage systems in BOP applications

Two-phase gravity-driven drainage systems are used in many applications within nuclear power Balance of Plant (BOP) applications such as the drain lines for moisture separator re-heaters (MSRs) and feedwater heaters. Design of these systems is typically based on industry-oriented guidelines and operator-based experience. Changes in plant operation, such as uprates and equipment modification and/or replacement, are relatively common as plants seek to generate more power with greater efficiency. These plant modifications may inadvertently change system operation from design conditions and impose undesirable system transients.This paper seeks to provide a method for analyzing BOP drainage systems in an effort to characterize and mitigate drain flow transients. Previous methodologies diagnose and evaluate drain instability through measurement, empirical analysis, and operational experience. This paper identifies methods that can be utilized to generate computational models of discrete plant drainage systems that decrease the level of speculation involved in previous analyses. Additionally, a real-world application of this method is presented to demonstrate how computer modeling can accurately mimic plant transients.     

Consideration of tolerable down times in the analysis of technical systems

In many technical applications the value of the probability of an undesired event is insufficient to adequately assess the failure behaviour of a system. Assessments of the probability that an undesired event within a limited time period can be returned to its original state, are important factors for judging the system.In the following, a characteristic value is introduced and methods for its quantification in complex systems are presented, which evaluate the frequency as well as the duration of the failures. This value is an extension of the conventional failure probability or failure frequency. Both are special cases of the new characteristic value.     

Digital Computers in Candu Safety Systems Part I History and Concepts

For many years, digital computers have been used in CANDU (CANada Deuterium Uranium) reactors for direct digital control as well as control room functions such as alarm annunciation, data logging and the display of operating data on the control panels. However, until recently computers were not used in the special safety systems. This paper examines the increasing role computers are playing in CANDU safety systems, especially the two shutdown systems. The reasons for this strong trend toward increased use of computers are outlined and recent designs are described, with special emphasis on system concepts. A companion paper (Part II) describes implementation details for the safety system computer applications and summarizes the experience gained so far during development and operation of these systems.     

The TFTR Charge Exchange Diagnostic Software Systems

This paper describes the applications software systems for computer control and monitoring of diagnostic hardware, and for data acquisition and analysis of the TFTR (Tokamak Fusion Test Reactor) Charge Exchange diagnostics. The TFTR Charge Exchange diagnostics are comprised of two autonomous systems, each consisting of up to six independent analyzer modules viewing the plasma at different angles and toroidal locations. Each system will have the capability of acquiring up to 2.5 megabytes of raw data for each shot. Users will have the capability of controlling all analyzers, and analyzing hydrogen mass species for up to ten analysis pulse time regions for multiple plasma shots. These features make the Charge Exchange systems among the largest diagnostic applications software systems on TFTR.     

Custom open source solutions for DIII-D data acquisition and control systems

Computer based control and data acquisition systems have long played a critical role in fusion research in the development and operation of experiments such as the DIII-D tokamak in San Diego. These systems require great flexibility in being able to control and tie together the many diverse subsystems that make up a tokamak, including power, cryogenic, vacuum, electrical, water, heating and computers. For well over a decade the DIII-D control and data acquisition systems have been running on Linux-based commodity computing hardware. This has provided DIII-D with a continual path of improvement to computing performance and capability while maintaining the usefulness and productivity of numerous custom developed software applications written over the years. The flexibility provided by these Linux based systems has allowed DIII-D to continue to utilize and support legacy CAMAC hardware in addition to incorporating newer PLC and data acquisition hardware. A number of in-house developed tools and applications have made these systems highly customizable and easily expandable in being able to meet the specific and growing needs of the DIII-D research program. Among the latest improvements to these systems have been upgrades to user interfaces, development of new control capabilities and increases to data acquisition capabilities. This paper will describe in detail the present state of the DIII-D computer based control and data acquisition systems and recent improvements that have been made.     

New-generation space thermionic nuclear power systems with out-of-core electricity generating systems

The basic problems of the development of long service life thermionic nuclear power systems for space applications for supplying power to transport power modules, intended for placing spacecraft in a geostationary orbit using electrorocket motors and for providing prolonged operation of onboard systems for up to 10–15 years, are examined. Concepts for power systems with multi- and single-element thermionic low-temperature energy-conversion systems, which are placed outside the reactor core and in which heat is delivered to the emitters using molybdenum-lithium heat pipes at 1600–1670 K, are discussed as an example. Computational results are presented for the electro- and thermophysical characteristics of electricity generating systems and power systems with different variants of the design-technological solutions, including the possibility of increasing the service life by reserving a part of the thermionic electrical power. The mass/size characteristics of the power systems with basic variants of the systems are obtained and recommendations based on research and development work are made, 8 figures, 8 references. Translated from Atomnaya énergiya, Vol. 89, No. 1, pp. 22–34, July, 2000.     

Large user-orientated systems of programs for structural analysis and design

The trend in the use of structural analysis programs is towards larger, more integrated user-orientated systems. The main aim of organizing structural analysis systems of programs appears to be to provide users with more versatile tools to reduce the required man-days and computing costs and to increase the scope and potential of the programs.A large modular system is described constituting the most widely used structural analysis packages developed by the CEGB. The principal motivation in developing the system is to rationalize and simplify the considerable diversification of applications and techniques currently available. The applications encompass elastic, thermal, dynamic, creep and plastic analyses of arbitrary two-dimensional and three-dimensional structures. The system uses a standardized form of input for all applications and provides user-aids such as mesh generation, error facilities, output facilities (online and graphical) as integrated system modules. Calculational packages at present integrated into the system comprise FLHE-BERSAFE (thermal and elastic, two and three dimensions), TESS (creep and plasticity, two dimensions), STAG21 (visco-elastic, two dimensions). Various element types and a comprehensive selection of different solution techniques based mainly on finite element displacement model can be used in the analyses.All data presented to the system are in the form of files (datalists) stored on 3330 magnetic disks. A comprehensive permanent disk library containing thermal and mechanical properties of the most commonly used materials is available to all users. The system is designed to be ‘open-ended’ in the sense that new subsystems can be augmented easily. It is envisaged that these additions will include structural analysis applications which are strictly outside the area of finite element analysis, e.g. frameworks.The internal structure and mode of operation of the system are described in detail. Several diverse examples of nuclear design problems which have been studied are given. An examination and comparison with other large structural analysis systems currently available are given, together with a discussion of possible future developments in this field.     

Relative Stability Analysis of Nonlinear Reactor Control Systems

In this paper, the relative stability characteristics of nonlinear power reactor control systems are analyzed. The analyses are based upon the stability-equation method. A simple reactor control system with one complex nonlinearity is considered first, followed by a reactor control system with two nonlinearities not related by a linear transfer function with low-pass characteristic. The results of analyses are presented in parameter-planes with various loci and boundaries, which are useful for engineers to design a system by choosing the proper values of adjustable parameters.     

Principles for engineering active-passive hydrodynamic control-and-safety systems for nuclear reactors

The principles for developing active-passive hydrodynamic systems for nuclear reactors are presented. The determination of the parameters of hydrodynamic control systems is examined: static characteristic, nonstationary motion (acceleration), and signaling of the state of a working organ. Recommendations are made concerning the calculation of the hydrodynamic control systems. Their use in the process of investigation, design, adjustment, and operation makes it is possible to determine the parameters and characteristics quickly by using simple means on the object. Familiarization with the particularities of the development of hydraulic control systems will aid in wider adoption of such systems in building nuclear reactors. Translated from Atomnaya énergiya, Vol. 106, No. 3, pp. 140–148, March, 2009.     

MOOSE: A parallel computational framework for coupled systems of nonlinear equations

Systems of coupled, nonlinear partial differential equations (PDEs) often arise in simulation of nuclear processes. MOOSE: Multiphysics Object Oriented Simulation Environment, a parallel computational framework targeted at the solution of such systems, is presented. As opposed to traditional data-flow oriented computational frameworks, MOOSE is instead founded on the mathematical principle of Jacobian-free Newton–Krylov (JFNK). Utilizing the mathematical structure present in JFNK, physics expressions are modularized into “Kernels,” allowing for rapid production of new simulation tools. In addition, systems are solved implicitly and fully coupled, employing physics-based preconditioning, which provides great flexibility even with large variance in time scales. A summary of the mathematics, an overview of the structure of MOOSE, and several representative solutions from applications built on the framework are presented.     

A Discussion of Tools and Techniques for Distributed Processor Based Control Systems Using CAMAC

This paper describes and analyzes various distributed processor architectures using commercially available CAMAC components. The general orientation is toward distributed control systems using Digital Equipment Corporation LSI-11 processors in a CAMAC environment. The paper describes in detail software tools available to simplify the development of applications software and to provide a high-level runtime environment both at the host and the remote processors. Discussion focuses on techniques for downloading of operating systems from a large host and applications tasks written in high-level languages. It also discusses software tools which enable tasks in the remote processors to exchange messages and data with tasks in the host in a simple and elegant way.     

深圳市梅山苑二期项目幼儿园土壤氡防治设计

简要介绍了土壤氡进入建筑物室内的途径和防治的一般方法,从封堵和排放两方面介绍了深圳市梅山苑二期项目幼儿园土壤氡防治的设计方案。工程采用的土壤氡防治措施都设有相应的监测系统,可以收集不同情况下的有关数据,为更深入的研究土壤氡析出和防治提供资料。     

Gain margin and phase margin analysis of a nuclear reactor controlsystem with multiple transport lags

A method for finding the boundaries of the constant gain margin and phase margin of control systems with transport lags and adjustable parameters is presented. The systems are first modified by adding a gain-phase margin tester, then the characteristic equations are formulated, and finally the stability equations are used to find the boundaries of the constant gain margin and phase margin. The main advantage of the proposed method is that it makes it possible to obtain complete information about the effects of adjustable parameters on the gain margin and phase margin and their corresponding crossover frequencies. In order to show the usefulness of the proposed method, a nuclear reactor control system with multiple transport lags is discussed as an example