太阳热水器的测量不确定度评定

按中华人民共和国国家计量技术规范《测量不确定度评定与表示JJF1059—1999》，太阳热水器测量必须以测量不确定度评定与表示，而现行实施的太阳热水器测量国家标准未给出具体的太阳热水器测量不确定度评定与表示方法。以太阳热水系统评定作为实例给出了太阳热水器测量不确定度评定及太阳热水器测量不确定度评定自动化。     

基于ASME及GB能量平衡法下锅炉热效率不确定度评定及敏感性分析

研究了ASME PTC4-2013标准和GB10184-2015的热效率计算方法以及不确定度计算理论,分别建立锅炉热效率及不确定度计算的理论模型,并以某350 MW机组超临界煤粉锅炉的热效率试验为例,对热效率结果进行了不确定度评定,研究各因素测量不确定度对锅炉热效率测试不确定度的贡献。结果表明:采用ASME试验标准,锅炉热效率测量试验质量高于GB标准;ASME标准下排烟温度测量不确定度分量、飞灰可燃物不确定度分量所占锅炉热效率合成不确定度权重值大于GB标准;ASME标准下空预器出口氧量测量不确定度分量所占锅炉热效率合成不确定度权重值小于GB标准;无论是ASME标准还是GB标准,排烟温度测量不确定度分量、空预器出口氧量测量不确定度分量均远大于其他测量参数不确定度分量;为了降低锅炉热效率不确定度,提高测试质量的途径应在试验设计与实施阶段优化对重要因素测量仪器的精度选择及测点布置。     

内燃机噪声测量不确定度

本文按《测量不确定度表示指南》和《测量不确定度评定与表示》规定的程序和方法,对引起内燃机噪声声功率级测量结果不确定度的因素(不包括声源本身的影响)及其累积效应进行不确定度分析与评定,旨在提高噪声测量结果的质量,促进降噪工作开展,并使测量不确定度评定在内燃机行业得到全面推广。     

发动机压力表示值测量的不确定度评定

根据压力表测量示值的数学模型,通过对输入量P的标准不确定度u(P)的评定和输入量u(P0)的不确定度评定,分析计算压力表示值合成不确定度的评定,提高发动机压力参数测量的精确度,对提高汽车发动机技术性能参数和实现节能减排具有指导意义:本评定方法也适用于其他行业的压力表示值测量的不确定度评定.     

家用燃气灶热效率测量及不确定度评定

按照GB16410-2007家用燃气灶热效率的测量原理和方法,对测量结果进行了不确定度评定,分析了各输入量对评定结果的影响情况。作为对比,分析了标准状态改变和按旧国标测量时的热效率不确定度。结果表明:铝锅修正系数、上下限锅正投影面积、试验气标态低热值和水的温升对家用灶热效率测量结果影响较大,影响程度依次降低。折算系数、测量时间和实验水量的测量不确定度可忽略不计。标准状态的改变对热效率测量结果不确定度评定的影响很小。相比旧国标,新国标测量结果具有更大的不确定度。     

透平试验数据的不确定度分析

测量不确定度是对测量结果质量的定量评定,是说明测量水平的主要指标,因此正确地评定和表述测量不确定度具有重要意义。文章将不确定度理论引入到透平试验测量数据分析,对试验结果进行综合分析,有效地提高了试验结果测量的准确性。     

基于Z-2700石墨炉原子吸收分光光度计测定水中铜的不确定度评定

基于Z-2700石墨炉原子吸收分光光度计测定水中铜的不确定度评定,分析了测量不确定度的来源,对各不确定度分量进行评定,得出测定水中铜的不确定度,为重金属痕量分析不确定度评定和表示提供参考,同时不确定度评定结果说明Z-2700石墨炉原子吸收分光光度计仪器具有较好的稳定性。     

船用柴油机功率测量不确定度评定

针对船用柴油机功率测量存在的不确定度,根据JJF1059-2012《测量不确定度评定与表示》中规定的方法,对标定工况下发动机功率测量不确定度进行评定,得出影响不确定度较大的分量以及原因,在此基础上,提出了对船用柴油机功率测量时测功器选择的建议。     

通用汽油机功率测量不确定度研究

按JJF1059-1999<测量不确定度评定与表示>规定的程序和方法,依据通用小型汽油机台架性能试验方法,对引起通用汽油机功率测量结果不确定度的因素逐一进行评定,计算各不确定度分量,找出不确定度主要因素,采取适当措施,提高通用汽油机功率测量结果的质量,促进测量不确定度评定工作在内燃机功率测量方面的应用.     

圆柱度的测量不确定度分析与评定

简要介绍了用Talyrond 2 65型圆度仪测量零件圆柱度的方法及其误差来源 ,通过分析 ,找出了对圆柱度测量不确定度起主要作用的误差分量 ,并举例说明了不同高度零件圆柱度测量不确定度的计算与评定方法。当测量的结果被用于过程控制时 ,不确定度的评价很重要。     

EDTA滴定法测量工业锅炉给水总硬度的不确定度评定

对EDTA滴定法测定工业锅炉给水总硬度的测量过程进行不确定度评定。充分考虑测量重复性、标准溶液的配制、滴定等过程对测量的影响，计算水中总硬度测量的相对合成标准不确定度为1．01×10^-2。     

Analysis of uncertainties in gas uptake measurements using the gravimetric method

A full analysis of the uncertainties in the calculation of the amount of gas absorbed or desorbed by a sample using the gravimetric technique has been made. The gravimetric technique provides a near direct measurement of the uptake of gas by continuously measuring the weight of the sample plus absorbed gas and is frequently used to characterise the uptake of hydrogen in potential hydrogen storage materials. These calculations provide the capability to determine the uncertainty in the final gas uptake measurement given knowledge of the measurement uncertainties. Uptake of hydrogen gas on activated carbon has been modelled to allow individual constants such as the buoyancy volumes as well as measurement uncertainties to be changed while determining the effect on the uptake uncertainty. The measurement uncertainties critical to minimising the overall uptake uncertainty have been identified and a comparison with another popular gas uptake method, the Sieverts technique, has been made.     

紫外荧光法测定柴油总硫含量不确定度的评定

通过测定柴油的总硫含量,按照测量不确定度的传播规律建立数学模型,讨论了柴油的总硫含量测量结果的不确定度主要来源于标准曲线、密度计的计量性、样品稀释和进样量,其中标准曲线引入的不确定度最大.通过对各相对不确定度分量分析计算,得到合成不确定度（uc）和扩展不确定度（U）.     

Radiation-induced uncertainty in laminar flame speed measured from propagating spherical flames

Laminar flame speeds measured using the propagating spherical flame method are inherently affected by radiation. Under certain conditions, a substantial uncertainty in laminar flame speed measurement is caused by radiation, which results in a great concern for kinetic mechanism validation and development. In this study, numerical simulations with detailed chemistry and different radiation models are conducted to examine the effects of radiation on spherical flame propagation. The emphasis is placed on quantifying the uncertainty and corrections associated with radiation in laminar flame speed measurements using propagating spherical flames. The radiation effects on flame speeds at normal and elevated temperatures and pressures are examined for different fuel/air mixtures including methane, propane, iso-octane, syngas, hydrogen, dimethyl ether, and n-heptane. The radiative effects are conservatively evaluated without considering radation reflection on the wall. It is found that radiation-induced uncertainty in laminar flame speeds is affected in the opposite ways by the initial temperature and pressure. An empirical correlation quantifying the uncertainty associated with radiation is obtained. This correlation is shown to work for different fuels at normal and elevated temperatures and pressures. Therefore, it can be directly used in spherical flame experiments measuring the laminar flame speed. Furthermore, a method to obtain the radiation-corrected flame speed (RCFS) is presented and it can be used for laminar flame speed measurement using the propagating spherical flame method.     

The manufacturing base under energy price uncertainty

This paper provides empirical and methodological analysis under a very important source of uncertainty: energy price uncertainty. In so doing, we show the impact of the energy price instability on the U.S. manufacturing output and the manufacturing sector's demand for energy. In addition, our method enables us to easily derive empirical comparative statistics results that can be compared to the theoretical results.     

Analysis of the uncertainties in gas uptake measurements using the Sieverts method

An analysis of the uncertainties in the calculation of the amount of gas absorbed or desorbed by a sample has been made for the manometric or Sieverts technique, commonly used for the determination of hydrogen uptake on potential hydrogen storage materials. The analytical derivations provide a means to calculate the uncertainty in each step of a hydrogen absorption isotherm. In addition, a Sieverts system is modelled to allow a detailed investigation of the effect of volumes and other parameters as well as the relative impact of the different measurement uncertainties. Reliable uncertainty estimates are especially important for authoritative measurements of gas uptake by carbons and other nanostructured materials used for hydrogen storage.     

A risk-averse optimization model for trading wind energy in a market environment under uncertainty

In this paper, a stochastic programming approach is proposed for trading wind energy in a market environment under uncertainty. Uncertainty in the energy market prices is the main cause of high volatility of profits achieved by power producers. The volatile and intermittent nature of wind energy represents another source of uncertainty. Hence, each uncertain parameter is modeled by scenarios, where each scenario represents a plausible realization of the uncertain parameters with an associated occurrence probability. Also, an appropriate risk measurement is considered. The proposed approach is applied on a realistic case study, based on a wind farm in Portugal. Finally, conclusions are duly drawn.     

Uncertainty assessment of a semi-empirical output voltage model for proton exchange membrane fuel cells

An accurate model of proton exchange membrane fuel cell (PEMFC) is essential for its characterization, performance analysis, and design of optimal control strategies. However, due to various disturbances and measurement noise in practical operation, a PEMFC presents high stochasticity and parameter uncertainty. Therefore, a semi-empirical output voltage model parameter estimation method based on variational Bayes (VB) PEMFC is proposed and combined with the Sobol sensitivity analysis method to analyze the relationship between the parameters of the model to be identified and the effect of the output voltage of the model under different noise and operating conditions. The numerical results show that the VB method is able to quantify the uncertainty of the parameter estimation results and has higher computational accuracy compared with the expectation maximization (EM) method. Compared with the Markov chain Monte Carlo (MCMC) method, the VB method is able to greatly reduce the computational effort and takes less time while satisfying the accuracy. Meanwhile, the sensitivity of the model parameters to be identified to the output voltage of the model under different noise and operating conditions is quantified using the Sobol method, which explains the variation of the posterior probability distribution results obtained using the VB method under different noise and operating conditions.