压缩天然气(CNG)加气机检定方法与检定过程中需注意问题的探讨

本文简要说明了CNG加气机开展强制检定的必要性;CNG加气机的构成和工作原理;CNG加气机的常规检定方法以及在检定过程中出现的常见问题和注意事项.     

CNG加气机计量检定方法探讨

一、加气机计量检定方法介绍 由于CNG加气机技术在我国发展较晚，我国目前尚没有加气机的国家计量检定规程。使用较为普遍的是JJG(川)80-2000《压缩天然气加气机》，还有各加气机生产厂家的企业标准及检验方法。     

压缩天然气加气机计量浅议

根据当前CNG技术发展和使用情况,文章介绍了压缩天然气的相关知识和应用情况,针对CNG加气机计量检定中出现的常见问题,从计量管理、计量检定原理和方法到相关问题分析等,阐述了影响加气机计量准确性的各种因素。     

常州市CNG加气站发展现状与加气机检定分析

文章主要论述了常州市CNG加气站的发展现状,并对目前所使用的CNG加气机的技术性能及现场检定方法进行了介绍,最后简要分析了目前压缩天然气加气站及CNG加气机现场检定所存在的问题及对策。     

CNG 加气机检定存在问题及解决方案的探讨

作为清洁能源的天然气已广泛地应用于汽车燃料,为汽车充装天然气的CNG加气机已全面应用于CNG加气站。由于涉及到贸易结算,按照国家计量法的要求,应对CNG加气机实施强制检定。现将实际检定过程中遇到的问题总结出来与大家探讨。     

CNG加气机检定存在问题及解决方案的探讨

作为清洁能源的天然气已广泛地应用于汽车燃料,为汽车充装天然气的CNG加气机已全面应用于CNG加气站。由于涉及到贸易结算,按照国家计量法的要求,应对CNG加气机实施强制检定。现将实际检定过程中遇到的问题总结出来与大家探讨。     

加气机现存问题的调研检测及解决方案

介绍了LPG和CNG加气机的工作原理,并依据对加气机的检测结果,分析了加气机计量检定中存在的问题,并提出了解决问题的相应措施。     

浅析CNG加气机检定装置建标及后续检定工作经验

本方简要介绍了CNG加气机检定装置的建标流程及在日常检定工作中发现存在的问题和注意事项以及对误差的影响,对一些县市级计量检定机构的加气机新建标有指导作用和实际使用帮助,对提高加气机的检定准确性具有一定的现实意义。     

压缩天然气加气机检定/校准作业指导书

一、适用范围本作业指导书适用于压缩天然气加气机又称CNG加气机（以下简称＂加气机＂）的首次检定、后续检定和使用中（修理后）检定或校准。二、引用文献1.JJG443-2006《压缩天然气加气机》检定规程2.GB18047-2000《车用压缩天然气》3.JJF1001-1998《通用计量术语及定义》     

CNG 加气机改造研究

介绍了CNG加气机计量原理和老旧加气机存在的问题,为符合新的加气机检定规程,提出了使用质量结算方式、采用手操器修改参数、对关键部位进行铅封、程序升级等改造措施,对指导加气机的改造,采用质量结算,防治作弊行为有重要的指导意义。     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.     

Evaluation of optical properties of highly scattering media by moments of distributions of times of flight of photons

A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue.     

Analysis of the rate of propagation of the wave of change of boiling modes

An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate agreement is demonstrated between the derived relations and experimental data.     

Estimation of potentialities of methods of summation of direct measurement errors

Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995.     

空压机轴承箱蜗壳温度探头油封改造

由于空压机进气侧轴承箱蜗壳温度探头密封效果不好,使空压机及其后续管道受到油污染。后将温度探头的O形圈密封改为骨架油封,杜绝了轴承箱漏油问题。文章简介空压机的结构和技术参数,详细介绍了骨架油封的制作和优点。     

Characteristics of mechanical properties of materials in studies of conditions of attainment of marginal states

It is shown that conditions of attainment of marginal states in the material of structural components are formulated on the basis of analysis of force and deformation criteria of formation and development of destruction. The parameters of these criteria are data on types of structural materials, standard and special characteristics of their mechanical properties, structural forms of considered elements of the equipment, and their operating stress loading. In this case, the construction of a system of state equations for describing interrelation of current damage, external actions, and responses to them is based on the concept of calculating variations in properties of materials at all stages of the design life cycle.     

Determination of parameters of microstructural inhomogeneity of deformation of metals by the method of modeling

The article suggests a method of evaluating the microstructural inhomogeneity of deformation of metals by modeling. The method includes the measurement of deformations of metal according to meshes of a dividing grid with small base and the calculation of the distribution parameters of microdeformations in model representation. It is shown that the modeling method makes it possible objectively to evaluate the microinhomogeneity of deformation of metals independently of the chosen mesh size of the dividing grid. New structural characteristics are introduced: the base and wave of variation expressing the degree of crumbling or amalgamation of metal grains by inhomogeneity of deformation.Translated from Problemy Prochnosti, No. 7, pp. 40–44, July, 1991.     

水三相点复现的不确定度评定

水三相点是开尔文热力学温度的唯一基准点，也是ITS-90国际温标重要的定义固定点。因此，水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来，中国计量科学研究院研制出一系列高质量的水三相点容器，加强了水三相点的研究，为不确定度的分析提供了更为可靠的实验依据。同时，不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此，根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明，其扩展不确定度为0．16mK(k=2．69，P=0．99)。