Ukraine
Numerical Modelling of Hydrogen Deflagration Dynamics in Enclosed Space
Sep 2009
Publication
A three-dimensional mathematical model of gaseous hydrogen deflagration in the enclosed space is developed. The process is described by the system of gas dynamics differential equations. Thermodynamic parameters of the mixture and its components are defined as functions of the local temperature and mixture composition. The concentration changes of the fuel and combustion products are determined using conservation laws taking into account Read More
Legal Regulation of Hydrogen in Germany and Ukraine as a Precondition for Energy Partnership and Energy Transition
Dec 2021
Publication
In August 2020 Germany and Ukraine launched an energy partnership that includes the development of a hydrogen economy. Ukraine has vast renewable energy resources for “green” hydrogen production and a gas transmission system for transportation instead of Russian natural gas. Based on estimates by Hydrogen Europe Ukraine can install 8000 MW of total electrolyser capacity by 2030. For these reasons Ukraine is among the EU’s priority partner Read More
The Influence of Hydrogen Desorption on Micromechanical Properties and Tribological Behavior of Iron and Carbon Steels
Dec 2018
Publication
The influence of the previous electrolytic hydrogenation on the micromechanical properties and tribological behavior of the surface layers of iron and carbon steels has been studied. The concentrations of diffusion-moving and residual hydrogen in steels are determined depending on the carbon content. It is shown that the amount of sorbed hydrogen is determined by the density of dislocations and the relative volume of cementite. After desorption of diffusio Read More
Specific Effects of Hydrogen Concentration on Resistance to Fracture of Ferrite-pearlitic Pipeline Steels
Aug 2019
Publication
The presented work is dedicated to evaluation of strain and fatigue behaviour of the ferrite-pearlite low-alloyed pipeline steels under known hydrogen concentration in a bulk of metal. Tensile test results have shown on the existence of some characteristic value of the hydrogen concentration CH at which the mechanism of hydrogen influence changes namely: below this value the enhanced plasticity (decreasing of the yield stress value) takes place and Read More
Laboratory Method for Simulating Hydrogen Assisted Degradation of Gas Pipeline Steels
Aug 2019
Publication
Integrity of natural gas transmission systems is of great importance for energy and environmental security. Deterioration occurs in gas transit pipelines due to operational conditions and action of corrosion and hydrogenating media and leads to changes in microstructure and mechanical properties of pipeline steels which influences on pipeline performance. Hydrogenation of metal during corrosion process together with working stresses facilitates a dev Read More
Using Hydrogen Reactors to Improve the Diesel Engine Performance
Apr 2022
Publication
This work is aimed at solving the problem of converting diesel power drives to diesel– hydrogen fuels which are more environmentally friendly and less expensive alternatives to diesel fuel. The method of increasing the energy efficiency of diesel fuels has been improved. The thermochemical essence of using methanol as an alternative fuel to increase energy efficiency based on the provisions of thermotechnics is considered. Alternative methanol fuel h Read More
Hydrogen Assisted Crack Initiation and Propagation in Nickel-cobalt Heat Resistant Superalloys
Aug 2019
Publication
It has been investigated the Ni-Co alloys (obtained from powder 0.1...0.3 mm under hot gaseous (in argon) isostatic pressure (up to 300 MPa) (Ni60Co15Cr8W8Al2Mo3) (Firth Rixon Metal Ltd Sheffield) and deformed (obtained by vacuum induced remealting) materials (Ni62Cr14Co10Mo5Nb3Al3Ti3) for gaseous turbine discs. Investigation has performed in the range of temperature 25…800°С and hydrogen pressure up to 70 MPa. By the 3D vis Read More
Factors Affecting Hydrogen Adsorption in Metal–Organic Frameworks: A Short Review
Jun 2021
Publication
Metal–organic frameworks (MOFs) have significant potential for hydrogen storage. The main benefit of MOFs is their reversible and high-rate hydrogen adsorption process whereas their biggest disadvantage is related to their operation at very low temperatures. In this study we describe selected examples of MOF structures studied for hydrogen adsorption and different factors affecting hydrogen adsorption in MOFs. Approaches to improving hydrogen Read More
Fatigue Crack Growth in Operated Gas Pipeline Steels
Jun 2020
Publication
Regularities of fatigue crack growth for pipeline steels of different strength are presented and the changes in fatigue behavior of these steels after long term operation are analyzed. Threshold values of stress intensity factor range are lower for operated steels comparing to the corresponding values for as received ones. During the testing in the simulated soil solution NS4 a barely noticeable tendency to increase the threshold values of SIF was traced. It was e Read More
Feature of Stress Corrosion Cracking of Degraded Gas Pipeline Steels
Aug 2019
Publication
Stress corrosion cracking (SCC) of steels can reduce the structural integrity of gas pipelines. To simulate in-service degradation of pipeline steels in laboratory the method of accelerated degradation consisted in subjecting specimens to electrolytic hydrogenation to loading up the certain plastic deformation and heating of specimen at 250°C was recently developed. The purpose of this paper was to analyse mechanical and SCC behaviour of in-service and i Read More
Micro and Macro Mechanical Analysis of Gas Pipeline Steels
Sep 2017
Publication
The actual safety margins of gas pipelines depend on a number of factors that include the mechanical characteristics of the material. The evolution with time of the metal properties can be evaluated by mechanical tests performed at different scales seeking for the best compromise between the simplicity of the experimental setup to be potentially employed in situ and the reliability of the results. Possible alternatives are comparatively assessed on pipeline Read More
Electrochemical Fracture Analysis of In-service Natural Gas Pipeline Steels
Dec 2018
Publication
Long-term operation of natural gas transit pipelines implies aging hydrogen-induced and stress corrosion cracking and it causes hydrogen embrittlement of steels degradation of mechanical properties associated to a safe serviceability of pipelines and failure risk increase. The implementation of effective diagnostic measures of pipelines steels degradation would allow planning actions in order to reduce a risk of fracture. In this paper a new scientifi Read More
Evaluation of the Protection Effectiveness Against Overpressure From Hydrogen-air Explosion
Sep 2017
Publication
The aim of this study is to assess the probability of the damage to hydrogen fuelling station personnel exposed to the hydrogen explosion shock wave. A three-dimensional mathematical model of the explosion of hydrogen-air cloud formed after the destruction of the high-pressure storage cylinders is developed. A computer technology how to define the personnel damage probability field on the basis of probit analysis of the generated shock wa Read More
Computational Modelling of Pressure Effects from Hydrogen Explosions
Sep 2007
Publication
The statement of the problem and algorithm of computational modelling of the processes of formation of the hydrogen-air mixture in the atmosphere its explosion (taking into account chemical interaction) and dispersion of the combustion materials in the open space with complex relief are presented. The finite-difference scheme was developed for the case of the three-dimensional system of gas dynamics equations complemented by the mass cons Read More
Effectiveness Evaluation of Facilities Protecting from Hydrogen-air Explosion Overpressure
Sep 2011
Publication
The physical processes of the explosion of the hydrogen cloud which is formed as a result of the instantaneous destruction of high-pressure cylinder in the fuelling station are investigated. To simulate the formation of hydrogen-air mixture and its combustion a three-dimensional model of an instantaneous explosion of the gas mixture based on the Euler equations supplemented by the conservation laws of mixture components solved by Godunov met Read More
Corrosion Cracking of Carbon Steels of Different Structure in the Hydrogen Sulfide Environment Under Static Load
Dec 2018
Publication
Hydrogen sulfide corrosion is one of the main reasons of steels destruction in the oil and gas industry. Damages appear as a result of corrosion and hydrogen embrittlement and corrosion cracking occurs when the load is applied. The influence of the steels structure on its stress corrosion cracking under the loads in hydrogen sulfide environment is insufficiently studied. The aim of the study is to determine the influence of the steels structure on its corrosion hy Read More
Stress Corrosion Cracking of Gas Pipeline Steels of Different Strength
Jul 2016
Publication
With the development of the natural gas industry gas transmission pipelines have been developed rapidly in terms of safety economy and efficiency. Our recent studies have shown that an important factor of main pipelines serviceability loss under their long-term service is the in-bulk metal degradation of the pipe wall. This leads to the loss of the initial mechanical properties primarily resistance to brittle fracture which were set in engineering calculation Read More
Brittle Fracture Manifestation in Gas Pipeline Steels after Long-term Operation
Dec 2020
Publication
Gas pipelines are exposed to operational loads combined with corrosive environment action during their long-term service. Complicated service conditions lead to a worsening of steel properties a reduction of serviceability of the whole object therefore a risk of its premature failure rises. Aware of the importance of the existing problem the aim of this study is the analysis of various mechanical properties of steels after their long-term operation on gas pipeli Read More
Fractographic Features of Long Term Operated Gas Pipeline Steels Fracture Under Impact Loading
Jan 2020
Publication
Pipelines during their service life subjected to operational degradation i.e. their mechanical characteristics worsened with time. Pronounced texture of pipe steels associated with their manufacturing process revealed itself in an essential difference in impact toughness determined for specimens cut in mutually perpendicular directions with respect to the pipe axis. Higher KCV values for longitudinal specimens as compared with transverse ones were explai Read More
Evaluation of Corrosion, Mechanical Properties and Hydrogen Embrittlement of Casing Pipe Steels with Different Microstructure
Dec 2021
Publication
In the research the corrosion and mechanical properties as well as susceptibility to hydrogen embrittlement of two casing pipe steels were investigated in order to assess their serviceability in corrosive and hydrogenating environments under operation in oil and gas wells. Two carbon steels with different microstructures were tested: the medium carbon steel (MCS) with bainitic microstructure and the medium-high carbon steel (MHCS) with ferrite–p Read More
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