Results of participation of Russian standards in key comparisons conducted by the Regional Metrological Organization for countries of the Asia-Pacific Region in the field of liquid and gas flow rate parameter measurement

Results of international key comparisons of the national standard for air flow rate and the working standard for water volumetric and mass flow rate are provided. Comparisons were made in 2009 within the framework of the Asia-Pacific Metrological Program (APMP) international organization. Russia was represented by state special standard for the unit of air flow rate (GET 150–85) and the highest accuracy working standard for the unit of water volumetric mass flow rate (RE VT 6–98). Results of comparison point to conformity of the metrological properties of these standards to the world level.     

Current Design Trends in the Modules of National Standards for the Units of Liquid Volumetric Flow Rate (Volume) within the Range of 10−5 to 103 mL/min

Measurement Techniques - The present article discusses the provision of metrological support for measuring liquid mass and volume in a flow, as well as liquid mass and volumetric flow rates within...     

State primary standard of unit of mass fraction and unit of mass concentration of moisture in solid substances and solid fabricated materials

The structure of the state primary standard of the unit of mass fraction of moisture and the unit of mass concentration of moisture in solid substances and solid fabricated materials is considered and the metrological characteristics of these units are presented.     

Two-phase cryogenic flow meters: Part I – Realization of the calorimetric method

While operating with multicomponent flows, one needs to determine such characteristics as temperature, pressure, mass flow rate and component composition – mass quality, and void fraction. The main attention is given to measurement of mass flow rate of the two-phase cryogenic flows which can be used for superconducting accelerators, refueling hydrogen system for space and liquid natural gas industry, in particular. On the one hand, a two-phase flow is one of the simplest cases of multi-component flows which can be observed in cryogenics. On the other hand, this is rather sophisticated problem in cryogenics to create two-phase flow meters and estimate their metrological characteristics. This problem is discussed. Two methods are suggested – calorimetric and pressure drop ones. Features of the calorimetric method are discussed in this part.     

Get 63-2019: State Primary Special Standard of Units of Mass and Volume of Liquid in a Flow and of Mass and Volume Flow Rates of a Liquid

Measurement Techniques - Elements in the improvement of the metrological assurance of measurements of the units of the mass and volume of an entrained liquid and of the mass and volumetric flow...     

Assurance of metrological traceability of water determination results in functional materials and pure substances

The problem of water determination in the creation of pure substances and new functional materials with a low moisture content is considered. The structure, metrological characteristics, and prospects of application of the state primary standard of mass fraction and mass (molar) concentration of water in solid and liquid substances and materials GET 173-2013 are presented. Examples of developing thermogravimetric and chemical analyses are provided.     

The ukrainian state standard for the liquid flow rate unit

Design and metrological characteristics are given for the Ukrainian state primary standard for the units of volume and mass liquid flow. __________ Translated from Izmeritel’naya Tekhnika, No. 6, pp. 39–45, June, 2007.     

The limits of metrological correctness of the Struya shaper

The hydrodynamic features and problems of the metrological correctness of the Struya flow meter shaper are considered. The instrument is designed to measure the flow rate of a liquid, to produce a uniform flow and to provide representative samples for subsequent analysis of the composition of a fluid dispersed medium. Translated from Izmeritel'naya Tekhnika, No. 9, pp. 54–59, September, 2008.     

Mathematical modeling of falling liquid film evaporation process

A mathematical model of evaporation process from a laminar falling liquid film on a vertical plate of constant temperature is presented. The model is developed with and without interfacial shear stress due to the vapor flow at the liquid film surface. The vapor pressure drop, vapor exit velocity and cooling rate are calculated for different liquid mass flow values. It is shown that lower liquid mass flow produces higher cooling rate. The results also show that the interfacial shear stress has a considerable negative effect on the cooling rate. It is proved that there exists an optimum distance between the plates, which gives the maximum volumetric cooling rate.     

GET 217–2018: State Primary Standard of Unit of Mass Fraction and Unit of Mass (Molar) Concentration of Inorganic Components in Aqueous Solutions Based on Gravimetric and Spectral Methods

Measurement Techniques - The metrological characteristics of GET 217–2018, the State Primary Standard of the unit of mass fraction and unit of mass (Molar) concentration of inorganic...     

高准确度静态质量法液体流量标准装置及其不确定度评价

本文介绍了一种高准确度质量法液体流量标准装置的设计方法,为对市场中出现的高准确度科里奥利质量流量计的量值传递提供了可能。文中介绍了装置设计过程中,为提高装置准确度用到的电动换向、衡器自校准、蒸馏水代替自来水等方法。试验证明,上述方法的应用使装置达到了预期的不确定度水平。文章还着重介绍了高准确度静态质量法液体流量标准装置不确定度的评价要点,对装置的不确定度水平进行了评定。     

The metrological backup for measurements of the flow rate and volume of liquids and gases in Russia

Brief historical information on the development of measurements of the flow rate and volume of liquids and gases in Russia is presented. The metrological characteristics of the State Standards and the main standard documents are given. The future prospects for the development of the standard base of the Mendeleev All-Russia Research Institute of Metrology are considered.     

Flow pattern, mass flow rate, pressure distribution, and temperature distribution of two-phase flow of HFC-134a inside short-tube orifices

New experimental data on the influence of short-tube orifice configuration, including diameter, length, length-to-diameter ratio (L/D), and orientation on the flow pattern, mass flow rate, and pressure distribution of HFC-134a inside the short-tube orifice are presented. Short-tube orifice diameters ranging between 0.605 and 1.2 mm with L/D ranging between 1.87 and 33 are used in the experiments. Three different forms of the metastable liquid flow, which are metastable liquid core flow, conical metastable liquid core flow, and full metastable liquid flow are visually observed. The short-tube orifice diameter has a significant effect on the increase in the flow rate. Conversely, the change in the orientation of the test section has no significant effect on the flow rate. The choke flow phenomenon disappears inside the short-tube orifice when L/D is less than 2.91. Based on the present data, a correlation for predicting the mass flow rate through short-tube orifices is proposed.     

Analysis of an ultrasonic method of measuring the flow rate of materials

A metrological analysis of an ultrasonic method of measuring the flow rate of materials is presented. Translated from Izmeritel'naya Tekhnika, No. 1, pp. 34–36, January, 2000.     

Two-phase cryogenic flow meters: Part II – How to realize the two-phase pressure drop method

The pressure drop method to find the mass flow rate of the two-phase helium and hydrogen flows is discussed in this paper. This method is based on a combination of the narrowing device and the RF void fraction sensor described earlier. Advantages of this approach with respect to the calorimetric one are demonstrated and its metrological characteristics for different flow patterns are estimated. The discussed cryogenic technologies and methods may be used for others applications, for example, to solve some tasks in oil-producing industry.     

Determining flow rate in discharge pipes by measuring velocity at one point of the outlet section of a convergent duct

Results are presented from a study of a method for determining flow rate in discharge pipes by measuring velocity at one point of the outlet section of a convergent duct that smoothly connects two pipes of different diameters. A metrological analysis, of the measurement method is presented. Translated from Izmeritel'naya Teknika, No. 4, pp. 40–45, April, 1996     

The Area of Application of Laval Nozzles in Flow-Rate Measurement Technique

Using examples of their use in standard and working instruments for measuring mass flow rate and a variety of gas volume flow rates, it is shown that critical nozzles and, particularly the Laval nozzle, can occupy an important place in the system of metrological facilities for this form of measurement.__________Translated from Izmeritel’naya Tekhnika, No. 4, pp. 48–52, April, 2005.     

Liquid film and droplet stability consideration as applied to wet steam flow

The state of art and ongoing research concerning the flow of wet steam in large steam turbines is reviewed, particularly from the viewpoint of the behavior of the liquid film deposited upon the stationary blading. New experimental results concerning the non-steady behavior of the film and the resultant wavelet formation patterns under the action of high-velocity low-pressure steam flow are presented. These results are then correlated as a flow regime “map” showing various flow regions in terms of steam velocity (or relative steam-film velocity since film velocity is relatively very small) vs. film flow rate per unit transverse distance. The distribution of liquid droplets shed from the blade trailing edge in the wake are studied as a function of distance downstream, steam velocity, and liquid film flow rate. In addition the droplet size is correlated in terms of critical droplet Weber number and compared with results of previous investigators. High-speed photographs of droplet distortions in a high-velocity air stream are also included.     

南钢KDON-20000/30000型内压缩流程空分设备变负荷操作实践

简介KDON-20000/30000型内压缩流程空分设备的工艺流程,分析空分设备变负荷能力的约束条件和变负荷过程中的物料平衡,结合生产实际,从下塔操作压力、变负荷时原料气量和产品气量的增减顺序、变负荷的速度和制氩系统的调节方面对空分设备变负荷过程中的操作提出建议,最后阐述变负荷过程中主冷液氧液位的调节作用和分子筛再生气量的稳定措施。     

Thermal patterns in evaporating liquid

In this paper, some of the preparatory experiments of the ESA sponsored space program CIMEX-1 are presented. A liquid layer of variable thickness is subject to a flow of inert gas. The non-uniform evaporation induced by the gas flow creates a temperature gradient parallel to the interface triggering in that way thermocapillary convection. The combined action of evaporation, thermocapillarity and gravity has been not completely clarified both theoretically and experimentally. The experiment presented in this work concerns a liquid layer of ethanol of 2.2 mm thickness in presence of a mass flow of Nitrogen whose intensity varies in the range of hundreds of milliliter per minute. The experiments were performed at an initial liquid temperature of 21°C. The patterns observed are strongly dependent on the flow rate of inert gas. A change in the instability patterns has been observed for a gas flow of about 1.7 l/min.