Improvement of the high-conductivity diaphragm from the composition of the reference 1st category of vacuum gauge reduction VOU-1

The article notes an increase in the number of new vacuum gauges undergoing primary verification at D. I. Mendeleyev Institute for Metrology VNIIM. The results are presented in the article in the form of a table reflecting the growth in the number of vacuum gauges of the most common modifications undergoing initial verification for the period from 2018 to the first quarter of 2021. There is also a diagram, which shows the overall growth in the number of new vacuum gauges undergoing initial verification The article mentions the principles of the measurements made by the reference installation of the 1st category of vacuum gauge reduction (VOU-1) The drawings of the installed diaphragms in of the system and as part of the improvement of the system, as well as a general calculation that shows how the properties of the system change after the diaphragm has been replaced.

Constructal Design Applied to the Geometric Evaluation of a T-Shaped Earth-Air Heat Exchanger

An Earth-Air Heat Exchanger (EAHE) is a device that consists of one or more buried ducts through which air is forced to flow. The surrounding soil is responsible for enabling thermal exchanges along with the installation, making the temperature at the outlet milder than the inlet. The objective of this work is to ally a numerical-analytical approach with the Constructal Design method and Exhaustive Search technique to minimize the soil volume occupation (V), minimize the air flow pressure drop (PD), and maximize the thermal potential (TP) of a T-shaped EAHE. Starting from a conventional EAHE composed of a straight duct, called Reference Installation (RI), two degrees of freedom (DOF) were considered: the ratio between the length of the bifurcated branch and the length of the main branch (L1/L0) and the ratio between the diameter of the bifurcated branch and the diameter of the main branch (D1/D0). Comparing with RI, different T-shaped EAHE geometries were identified to reduce V by 23% and PD by 62% and to increase TP by 21%; and when these three performance parameters were concomitantly considered another T-shaped EAHE geometric configuration allowed to reach an improvement of around 27% when compared with the RI.

Design of Mooring Solutions and Array Systems for Point Absorbing Wave Energy Devices—Methodology and Application

Most of the ocean energy technologies are considered to be in a pre-commercial phase and need technical development. This study focuses on the design of mooring solutions and compares array systems of a specific floating point-absorbing wave energy converter (WEC) developed by the company Waves4Power. A full-scale prototype of the WEC is installed in Runde (Norway) where it is moored with three polyester mooring lines, each having one floater and one gravity anchor. Based on this reference installation, the method of systems engineering was used to propose 22 conceptual mooring solutions for different array systems. They were compared and reduced to four top concepts in a systematic elimination procedure using Pugh and Kesselring matrices. The top concepts were assessed in detail by means of levelized cost of energy (LCOE), life cycle analysis (LCA), and risk analyses. The fatigue life of the mooring lines and the energy capture were calculated using results obtained from coupled hydrodynamic and structure response analyses in the dnv-gl deepc software. Two final concepts were proposed for the water depths 75 and 200 m.

A reference installation based on thermo-gravimetric analysis with mass-spectrometric detection as a part of the state primary standard GET 173

The issue of assuring the traceability of the results of water determination in solid and liquid substances and materials is discussed. The stages of development and improvement, as well as composition of the State primary measurement standard of mass fraction and mass (molar) concentration of water in liquid and solid substances and materials (GET 173) are considered. The problems of the limited applicability of GET 173 in case of separation of water with different binding energies and impossibility of conducting qualitative analysis of non-water volatile compounds during heating of substances and materials are revealed. The results regarding upgrading of GET 173 due to incorporation of additional reference installation which implements the methods of thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC) and mass-spectrometry (MS) are presented. The composition and operating principle of the new reference unit are described. An algorithm for estimating the uncertainty of reproducing a unit mass fraction of water using this reference facility is presented and sources of the uncertainty are identified. The results of the experiment on determination of the lower limit of the reproduction range for a unit water mass fraction are presented. We also present the results of comparisons regarding determination of the water mass fraction in crystalline hydrates obtained using the improved State primary standard and high-precision installations of the metrological and leading sectorial research institutes of the European countries. The results of developing a certified reference material of water mass fraction in sodium molybdate dihydrate (Na2MoO4· 2H2O CRM UNIIM 10911–2017 intended for metrological support of measurement instruments and measurement procedures based on thermo-gravimetric method are presented. Additional possibilities which result from the introduction of a new reference installation into the state primary standard of GET 173 are disclosed: identification and the quantification of non-water volatile components, adjustment of drying regimes both in laboratory and process conditions, determination of water content as one of the main impurities in estimating mass fraction of the main component of high-purity substances.

Comparison of Mooring Solutions and Array Systems for Point Absorbing Wave Energy Devices

Most of the ocean energy technologies are considered to be in a pre-commercial phase and need technical development. This study focuses on design of mooring solutions and compares array systems of a specific floating point-absorbing wave energy converter (WEC) developed by the company Waves4Power. A full-scale prototype of the WEC is installed in Runde (Norway) where it is moored with three polyester mooring lines, each having one floater and one gravity anchor. Based on this reference installation, the method of systems engineering was used to propose twenty-two conceptual mooring solutions for different array systems. They were compared and reduced to four top concepts in a systematic elimination procedure using Pugh and Kesselring matrices. The top concepts were assessed in detail by means of LCOE (levelised cost of energy), LCA (life cycle analysis) and risk analyses. The fatigue life of the mooring lines and the energy capture were calculated using results obtained from coupled hydrodynamic and structure response analyses in the DNV-GL DeepC software. Two final concepts were proposed for the water depths 75 and 200 m.

The Wärtsilä 32GD engine for heavy gases

The Wärtsilä 32GD engine is a stationary turbocharged “Gas-Diesel” engine which can operate on gas and oil fuel. The direct high-pressure gas injection is applied in this engine. The sophisticated control system of the engine allows operation on gas and oil fuel with very wide range of gas/oil fuel ratio which provides a unique flexibility of fuel usage. The Wärtsilä 32GD technology offers possibility to use good quality gas or heavier gases i.e. with high content of heavier hydrocarbons. The Wärtsilä 32GD engine development and the most important components of the Wärtsilä 32GD engine are presented. The working principles, operation mode, the engine performance and emission levels are described in the paper as well. The paper includes also specification for gas and oil fuels that can be used for the engine operation. The paper is concluded with some typical applications, reference installation and experience from running the engines on challenging fuels.