水泵试验台流量原位标定系统研制

为保证水泵试验台精度和试验稳定性,除了选择高精度的测流设备外,还应有高精度的流量原位标定装置。提出了称重-容积法原位标定方法,在水泵试验台上实现了流量计的正、反向原位标定。根据系统设计目标,对供水加力水泵、称重桶、水池、气动换向器和标准金属量器分别进行了选型和计算。依据测量不确定度理论,标定系统不确定度主要由标准量器、计时器、换向器和容积法标定传感器装置等不确定度组成,计算了称重桶容积法、换向器和整个系统的不确定度。经试验和计算,系统扩展不确定度为0.136%,系统流量稳定度为0.0212%。计算和压力脉动测试结果表明采用溢流供水池和变频调速加力泵相结合的方法可保证系统标定时压力稳定。称重-容积法原位标定方法将称重法和容积法有效的结合起来,在水泵试验台中成功地得到了应用。该方法达到了既保证精度又降低造价的目的,具有较好的推广应用前景。     

明渠时差法流量计流量计算方法分析研究

目前国内外对明渠时差法流量计流量计算方法研究较少,对时差法流量计流量计算方法进行系统完整的研究,从时差法测验原理、理论标定系数k1的计算方法、水道断面面积的计算方法、现场标定系数k2的计算方法,详细阐述了明渠时差法流量计流量计算方法,提出了线性插值计算理论标定系数k1的方法。以南水北调输水断面运河站为例采用线性插值计算理论标定系数k1的方法,进行时差法流量计流量计算,计算结果与流速仪法对比显示两者一致性较好,误差可控。进而为工程技术人员提供参考;为国产化时差测流装置提供重要技术支撑;为我国重点通航河道和低流速实时在线流量监测提供技术保障。     

提高水力机械模型效率试验精度方法探讨

在总结中国水利水电科学研究院水力机械模型试验台提高水轮机某些试验精度方法的基础上,根据对测试误差的来源分析,从完善测试设备原位标定系统和方法、减小标定误差及减小随机误差等3个方面提出了提高试验精度的措施方法。     

宽带微型ADCP用于渠道流量测验的研究

应用微型ADCP（Stream Pro ADCP）和传统的流速仪，进行了渠道流量同步比测，并对宽带ADCP标定资料进行分析，验证其流量测验的精度和实用性，拓宽了渠道流量测验和在线流量计的标定方法。结果表明，在渠道和小河流中使用ADCP进行流量测验和标定宽带ADCP，其精度完全能满足国家流量测验规范要求，其简便快捷的流量测验方法可节省人力、物力。     

多声路超声波流量计校准及相关问题探讨

为了标定UF-911超声波流量计的测量精度,在国家水大流量计量站利用静态容积法进行了一次针对实际泵站的模型试验和一次准确度标定试验.结合这2次试验,对其校准过程、测量数据、误差等内容进行了简单的介绍和分析,对超声波测流方法的实验室校准以及实际工程应用中的相关问题进行了探讨,对超声波流量计的工程应用具有一定的指导意义.     

南水北调工程泵站在线流量测量可行性研究

简述轴流泵装置模型上进行的超声波、流道阻力损失法测流可行性试验研究。以试验台电磁流量计测流作为基准,给出了超声波测流布置位置和精度;给出了实现流道阻力损失法测流部位、流量系数和压差系数,建议结合南水北调工程针对超声波法用于非标准圆断面测流进行深入研究,实现南水北调工程泵站在线流量精确测量是可行的。     

电厂明渠流量计干式标定中的疑难问题及解决方法

着重介绍多声道超声波流量计在明渠计量实际标定中产生的主要疑难问题,分析干式标定误差产生原因及其解决方法,为从事明渠流量测量设计、安装及现场维护检修人员提供参考．     

电磁流量计测量直管内速度及管长的CFD 研究

电磁流量计是一种广泛采用的流量测量仪表,测量直管长度对于保证测量管内流速轴对称分布及电磁流量计计量精度起着关键性作用.本文采用CFD数值手段对电磁流量计测量直管长度及管内流速轴对称分布特性展开研究.为了准确地研究流速分布的轴对称特性,提出了定量衡量流速分布轴对称程度的速度对称偏差度,并基于此研究了不同内径、不同过流量条件下测量管内的流速分布轴对称特性和电磁流量计对测量直管长度的要求,为电磁流量计的检定、安装、应用提供科学理论依据,为依托项目建立高精度流量计量标准装置奠定基础.     

鼓风曝气系统风量测量装置更新的选型与安装调试

分析了鼓风曝气系统原涡街流量计量装置测量失败的原因,并对其进行技术更新。经对比,选择了某差压式流量计,简述了其原理和特点。重点介绍了该流量计传感器安装位置的方案对比、选择,测量系统的配置选择,调试及运行等。更新后长期的运行实践表明,新的测量系统精度和稳定性均满足要求。     

外贴式超声波流量计的测量与在线校准

针对众多新型流量计的广泛应用和水量计量流量计难以离线送检的难题,通过考察国内外流量计在线校准方法与研究现状,在选定的河工模型供水管道以及流量标准装置上采用外贴式超声波流量计,并开展了测试研究。同时,介绍了试验方案以及实流在线校准的技术要求、测量过程与误差计算。结果表明,采用外贴式超声波流量测量计在线校准的误差可控制在0.5%~1%,且重复性好,是合适的流量检测设备。研究成果可为水利行业有效开展管道流量计在线校准提供技术参考。     

声学多普勒流速仪计量检定工作分析

从水量准确计量为切入点,根据声学多普勒流速仪推广使用中存在的计量检定问题,结合水利水文专业计量体系的促进和发展,论证了声学多普勒流速仪计量检定工作开展的必要性。从声学多普勒流速仪工作原理出发,探讨了利用水槽检定该类仪器的原理和方法,分析了检定方法的可行性。研究说明,利用现有水槽检定还存在一定难点,如何利用现有水槽,还需要进行试验。     

Multi-Objective Parameter Calibration and Multi-Attribute Decision-Making: An Application to Conceptual Hydrological Model Calibration

For calibrating the conceptual hydrological models (CHM), the traditional calibration method with a single objective cannot properly measure all the behaviors of the hydrological system. To obtain a successful parameters calibration, in this paper, we propose a multi-objective cultural self-adaptive electromagnetism-like mechanism (MOCSEM) algorithm, which is first implemented in solving the parameters calibration problem of CHM. In this algorithm, a self-adaptive parameter is applied in local search operation for adjusting the values of parameters dynamically. Meanwhile, cultural algorithm (CA) is adopted to keep a good diversity and uniformity of Pareto-optimal solutions (POS). MOCSEM is tested, firstly, by several benchmark test problems. After achieving satisfactory performance on the test problems, a case study is implemented for parameter calibration of a CHM by comparing the properties of POS obtained by the MOCSEM and other methods. Finally, when the optimization problem quickly becomes a decision-making problem because of the multiple objectives in CHM, fuzzy technique for order preference by similarity to an ideal solution method has been used to rank the POS and select the optimal scheme. The results show that the MOCSEM algorithm can provide high-accuracy parameters of CHM on various decision-making scenarios.     

PIV流场量测中图像变形的修正

在用PIV技术测量流速场时，会因图像的几何变形而引起计算的误差。本文试验标定了不同型号的摄像系统的变形误差，论证了图像几何变形的特性，并提出了相应的校正公式，推荐的系统配置经校正后的图像几何变形误差小于0．4个象素。     

Particle Swarm Optimization for Automatic Calibration of Large Scale Water Quality Model (CE-QUAL-W2): Application to Karkheh Reservoir,Iran

An automatic calibration of water quality model is developed in this research. Automatic calibration as the process to determine the parameters appearing in the equations of a 2-dimensional, hydrodynamic, and water quality models (CE-QUAL-W2) is carried out with Particle Swarm technique as an optimization tool. In the calibration of the CE-QUAl-W2 model, evaporation as a significant parameter influences the thermal profile and water surface elevation in reservoir, simultaneously. Therefore to consider the simultaneous effects of the water temperature variations on water surface elevation in the reservoir, a multi objective technique is used to minimize the weighted sum of total deviations of temperature from field data at check points on monitoring days and those of water surface elevation on daily monitoring period. The proposed approach overcomes the high computational efforts required if a conventional calibration search technique was used, while retaining the quality of the final calibration results. The automatic calibration approach is applied in temperature and water budget calibration of Karkheh reservoir in Iran. Applying the proposed automatic calibration approach, shows the produced results by the CE-QUAL-W2 model with the calibrated coefficients agree closely with a set of field data.     

电气试验仪器仪表校验不确定度的分析

将以源检表法技术应用于电气试验仪器仪表的校验，同时对校验数据的不确定度及允许误差进行分析，使检定速度和准确性得到明显提高，满足了试验要求，也降低了试验成本。     

Evolving Effective Hydraulic Model for Municipal Water Systems

Constructing a robust hydraulic network model is vitally important, but a time-consuming task. Over last two decades, several approaches using optimization techniques have been developed for identifying model parameters. Although most of the methods can make the model agree with field observations, few are able to achieve a good level of accuracy in terms of determining the correct model parameters for a water distribution system. The previously developed methods appear to be lacking versatility for users to specify calibration tasks given real data for a real system. This paper proposes a comprehensive framework for evolving a hydraulic network model. Calibration tasks can be specified according to data availability and model application requirements. It allows an engineer to (1) flexibly choose any combination of the model parameters such as pipe roughness, junction demand and link (pipes, valves and pumps) operational status; (2) easily aggregate model parameters to reduce the problem dimension for expeditious calculation and (3) consistently specify boundary conditions and junction demand loadings that are corresponding to field data collection. A model calibration is then defined as an implicit nonlinear optimization problem, which is solved by employing a competent evolutionary algorithm. With this methodology, a modeler can be fully assisted to carry out not only a single parameter optimization run, but also a variety of calibration tasks in a progressive manner according to practical system conditions, thus it is possible to achieve a good model calibration with high level of confidence. The method has been applied to the model of a municipal water system to demonstrate the efficacy and robustness of the evolutionary modeling practices.     

Calibration and Control for Estuary System under Uncertainty

A comprehensive stochastic management methodology is developed for a distributed-parameter estuary system (DPES) which is described by partial differential equations (PDEs). The proposed stochastic management methodology consists of uncertainty-based calibration (i.e. parameter estimation under uncertainty) and uncertainty-based control (i.e. determination of optimal freshwater inflows into the estuary under uncertainty). The technique for uncertainty-based calibration is based on Gauss–Newton minimization method and uncertainty analysis method such as Rosenblueth's point estimate method or Harr's point estimate method. The uncertainty-based calibration technique is used to estimate the optimal parameters such as Manning's roughness coefficient and dispersion coefficient in the PDEs while considering the uncertainties in the boundary conditions or initial conditions for the PDEs. The technique for uncertainty-based control is based on a real-time control method which is discrete-time stochastic linear quadratic feedback control. Real-time control is achieved by feedback control which uses salinities at test stations in the estuary as the state vector and controlled freshwater inflows as the control vector. The feedback control law determines the real-time control vector using observed states in a manner that best approximates desired states and controls (freshwater inflows). This new methodology for real-time control has been applied to the Lavaca–Tres Palacios Estuary in Texas for purposes of testing and illustration.     

Partial Least Squares local calibration of a UV-visible spectrometer used for in situ measurements of COD and TSS concentrations in urban drainage systems.

Recent UV-visible spectrometers deliver on line and in situ absorbance spectra in wastewater or stormwater transported in urban drainage systems. After calibration with local data sets, spectra can be used to estimate pollutant concentrations. Calibration methods are usually based on PLS (Partial Least Squares) regression. Their most important difficulty lies in the identification of the number of both i) the latent vectors and ii) the independent variables. A method is proposed to identify these variables, based on an exhaustive tests procedure (Jackknife cross validation and matrix of prediction indicator). It was applied to estimate TSS (total suspended solids) or COD (chemical oxygen demand) concentrations at the inlet of a storage-settling tank in a stormwater separate sewer system, and compared to three other calibration methods used either for turbidity meters or UV-visible spectrometers. With the available calibration data set: i) the spectrometer gives results with better prediction quality than the turbidity meter, ii) for the spectrometer, local calibration gives better results than global calibration, iii) the proposed PLS method gives results with a similar order of magnitude in uncertainties as the manufacturer local calibration method, but is more open and transparent for the user. Similar results were obtained for a second data set.     

TPY级电流互感器在班多水电站中的应用

具有暂态误差性能的TPY电流互感器广泛应用于高电压等级电力系统及大容量发电机变压器组的差动保护中。文章简要介绍了班多水电站变压器差动保护选择TPY电流互感器的原因,并介绍了TPY电流互感器参数选择及校验的计算方法。指出了针对中小型机组接入大系统,选择TPY型电流互感器参数的重点,并列举说明了校验TPY电流互感器等效二次极限电动势及暂态误差不满足规范要求情况下的解决办法。     

CCD遥测垂线坐标仪在大坝安全监测中的应用与研究

CCD遥测垂线坐标仪以先进的图像位移传感技术作为支撑,近年来发展很快.文章介绍了CCD遥测垂线坐标仪的基本原理和结构,并结合垂线坐标仪在工程中的应用与取得的研究成果,对遥测垂线坐标仪的选型、检验校准、与常规人工观测比对分析以及运行评价体系进行了论述.