Liquid and Gaseous Energy Resources: Table of Contents

Cylindrical shell pressure vessel profile variation footprint in strain comparison of test data with numerical analysis

Pany, Chitaranjan — 2021-12-23T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 1, Issue 2, 2021, p. 91-101.
Chitaranjan Pany
The strain comparison of a pressure vessel made of HSLA 15CDV6 in a cylindrical shell membrane region in a pressure test is discussed in this paper. Non-linear finite element analysis (FEA) of thin-walled cylindrical pressure vessels has been carried out using ANSYS. Hoop strain obtained from FEA is not compared well with the pressure test data at the membrane location of the cylindrical shell where the strain gauge is mounted. So to explain the reasons for the difference in strains at the membrane region, the profile of the cylindrical shell at strain gauge region has been measured. The 3D FEA of the cylindrical region with the measured profile is performed. It is found that with measured profile the FEA is giving the strain close to measured strain in the hoop direction. This leads to the increase in strain and stress as having been demonstrated through mathematical modeling in the deviated profiles variations of cylindrical shells. Therefore, the stresses in the deviated region are greater than those that would exist in an undeviated cylindrical shell, which reduces the margin of safety with respect to the yield strength of the material and causes stress concentration. The details of the stress analysis carried out including the effect of measured 3D profile variation are discussed in this paper.

History of technical diagnostics and repair organization systems in industry

Valeev, A. R. — 2022-06-30T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 2, Issue 1, 2022, p. 31-37.
A. R. Valeev, N. A. Atroshchenko, B. G. Kharrasov
The article discusses history of technical diagnostics and repair organization in industry in Russia. The history of formation of the principles of repair, which were further formed into a system of preventive and planned repairs, is considered. At one of the stages of industrial development and the formation of repair organization systems, it became necessary to develop technical diagnostics of machines and equipment that can be carried out on working equipment. The main reasons and key points at various stages of the formation of technical diagnostics and repair organization are considered.

Rehabilitation coatings-current challenges and opportunities for the future

Al-Sahari, A. — 2022-06-30T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 2, Issue 1, 2022, p. 1-14.
A. Al-Sahari, Ihsan Ul-Haq Toor
Underground pipelines used for oil, gas and water distribution in Saudi Arabia and gulf region are estimated more than 33000 km in length with a range of diameters from 8 and 80 inch. Most of these pipelines are buried in different types of corrosive soil conditions and in most cases an external coating is employed along with cathodic protection (CP). Most of the existing pipelines are over 30 years old now and this is the stage to carry out rehabilitation projects for life extension of this aging infrastructure. The selection of the suitable coating systems for the rehabilitation projects is a very complicated process as it requires in depth understanding the coating/environments interactions in that particular environment along with application challenges. This paper discusses in detail the different types of external underground pipeline coating types and their selection criteria for rehabilitation projects along with recent trends and future recommendations.

Use of gas reduction energy at a gas distribution station

Karimova, Aigul — 2022-06-30T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 2, Issue 1, 2022, p. 15-19.
Aigul Karimova, Regina Farukhshina
The issue of utilization of excess energy of throttled natural gas is still relevant today. To solve it, various devices are used, based on such principles as on the Ranque-Hilsch vortex effect, temperature stratification using the Leontief tube, expander-generator sets and devices based on the Hartmann-Sprenger effect. One of the most common devices at gas distribution stations (gas gate station) is the turboexpander. The principle of its operation is based on the expansion of the gas flow with the performance of external mechanical work. Taking into account the increased interest in hydrogen fuel in connection with the course announced by the UN for decarbonization of production by 2050, the modern gas transmission system can become a secondary source of electricity for hydrogen production, thereby solving the problem of excess pressure energy utilization at gas distribution stations. The technological solution for using this energy is the installation of turboexpanders and electrolysis of water at gate stations in order to produce hydrogen.

Determination of the amount of oil product vapours from the tank based on monitoring the operation of the breathing valve

Glushkov, Semyon — 2022-06-30T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 2, Issue 1, 2022, p. 44-50.
Semyon Glushkov, Anvar Valeev
The development of methods for calculating losses of oil and petroleum products vapours from the tank has been going on for a long time. Systems that allow for more accurate calculations are also being developed along the way. In each country, and sometimes in each company, there are their own methods for determining the loss of light hydrocarbon fractions from losses from the tank through the breathing valve. In addition, losses are divided into “working losses” and “standing losses”. In each technique, there are both pros and cons. The most characteristic disadvantage of each technique is its applicability only to the conditions in which it was developed, due to the presence of correction coefficients. This article proposes a new technique for determining the loss of hydrocarbons vapours from the tank through the breathing valve, both from “working losses” and from “standing losses”. In the course of the work, formulas were obtained for calculating the flow rate Q∆P,h through the breathing valve, which depends on the degree of opening of the pressure plate and overpressure. An experiment was conducted, instrumentally proving the application of the developed methodology. And also, the equipment is selected and recommendations on its installation and use are given.

Utilization of low-potential secondary energy resources at oil pumping station

Dashkin, Ravil — 2022-06-30T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 2, Issue 1, 2022, p. 38-43.
Ravil Dashkin, Evgeny Muftakhov
The article considers the sources of low-potential heat at oil pumping station, estimates the amount of heat of technological processes that is irretrievably lost in the environment from the oil ACD, cooling systems of electric motors and wastewater treatment plants, and also presents possible ways of utilization and useful use of this heat using heat pumps.

On the use of a network of trunk pipelines to compensate for the shortage of water resources at the expense of the country’s deep Siberian rivers

Mastobaev, Boris N. — 2022-06-30T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 2, Issue 1, 2022, p. 20-30.
Boris N. Mastobaev, Rinat M. Karimov, Anvar R. Valeev, Radmir R. Tashbulatov, Alexander V. Kolchin, Evgeniya A. Lokshina
The paper discusses topical issues and problems of water supply in scarce and arid regions of the country, including the redistribution of water flows from high-flowing Siberian rivers, which are heavily overflowing during the flood period. In particular, an overview of world experience in solving water supply problems is given, both through desalination of sea water and the use of underground sources, and through the construction of canals and main water pipelines, from futuristic ideas to projects that have already been implemented and have many years of positive operating experience. Special attention is paid to the domestic union experience, plans to turn large rivers to supply the Central Asian republics, the world’s first nuclear plants for desalination of sea water and a main water conduit to supply the Mangyshlak Peninsula. Based on the results of the analysis performed, the main disadvantages, areas, limitations and advantages of various water supply options are identified, which make it possible to draw a conclusion about the possibility of involving unclaimed capacities of main oil and gas pipelines to solve the problems of compensating for the shortage of water resources at the expense of the country's deep Siberian rivers.

Numerical simulation of the supercritical carbon dioxide flow in converted marine pipelines

Davletbaev, Askar — 2022-11-26T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 2, Issue 2, 2022, p. 66-72.
Askar Davletbaev, Marina Ilyaeva
The article discusses the features of modeling the flow of supercritical carbon dioxide in offshore pipelines of complex geometry. The concept is based on the replacement of the initial oil and gas in field pipelines for the re-injection of carbon dioxide into the reservoir with the purpose of further disposal. Various variants of the component composition are considered depending on the origin of the fluid. Needed initial operating parameters for conversion are defined.

Study of horizontal aerodynamic force directed against a fluid flow at oscillations of elastically suspended plate

Zotov, Alexey — 2022-12-04T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 2, Issue 2, 2022, p. 58-65.
Alexey Zotov, Anvar Valeev
The Paper is devoted to the construction and study of a mathematical model of plate vibrations in the incoming flow of the medium. A system with two degrees of freedom was investigated. Within the framework of the proposed mathematical model, stable modes of plate vibrations are obtained, in which the horizontal aerodynamic force acting on the plate is directed against the incoming flow. In this case, the angle between the velocity vector of the pressure center of the plate and the plate itself is almost constant.

Non-waste energy and resource-saving heterogeneous catalytic methods of obtaining and transformation of cyclic acetalies and gem-dichlorocyclopropanes

Borisova, U. G. — 2022-12-06T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 2, Issue 2, 2022, p. 51-57.
U. G. Borisova, R. R. Daminev, T. P. Mudrik, G. Z. Raskil’dina
New methods and ways of using heterogeneous zeolite catalysts – H-Y, H-Beta, H-MOR, H-ZSM-5 and micro- meso-porous – H-Ymmm and others in organic synthesis were studied. Using the example of available petrochemical compounds such as polyols, olefins, and dienes, the possibilities of carrying out cyclization and condensation reactions in the presence of zeolites of various structural types are shown. It has been established that the H-Beta zeolite catalyst provides a quantitative yield of ethers and esters during the interaction of olefins – substituted vinyl-gem-dichlorocyclopropanes – with linear alcohols and acids, respectively. It has been determined that the condensation of styrene and an equimolar mixture of 4-hydroxymethyl-1,3-dioxolane and 5-hydroxy-1,3-dioxane in the presence of the H-Beta catalyst proceeds with the formation of ethers, while the ratio of 5 and 6-membered isomeric products = 1.2:1. Multicomponent condensations successfully proceed in one stage in the presence of wide-pore zeolites.

Application of clustering algorithms to detect abnormal state of pumping equipment

Valeev, Anvar — 2022-12-10T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 2, Issue 2, 2022, p. 73-79.
Anvar Valeev, Aliia Siraeva, Yang Chen
The article is devoted to detection of an abnormal and pre-emergency state of pumping equipment using clustering and anomaly search algorithms. A background for research is the need to search for and apply methods for assessing the technical condition and identifying emerging defects in an automated mode for a wide range of equipment that give results at an earlier stage than existing ones. To achieve this goal, we consider the use of machine learning methods to analyze the parameters of equipment operation over a certain time period in order to create an algorithm for detecting anomalies in data, which in this case will be signs of abnormal operation. This article discusses the application of clustering based on the k-means method. So, in this research three normal operating modes of pumping equipment were recognized in the synthesized data. Based on the analysis of the distribution of each measurement to the corresponding nearest cluster centroid, the maximum distance from each measurement point to it was determined, which further served as a criterion for classifying a certain measurement as data outliers. As a result of the analysis, five measurements were identified that correspond to the abnormal operation of oil pumping equipment. Also, the ranges of normal operation of the equipment were compiled for each of the measured parameters of its operation, which forms the threshold values for classifying the state of the equipment as an abnormal or emergency state. The proposed approach has such advantages as the possibility of full automation, adaptation to various operating modes of the equipment, no need to share data outside the pumping station, early detection of emerging defects and the onset of an emergency.

Transportation of hydrogen by main gas pipelines as a methane-hydrogen mixture

Darsaliya, N. M. — 2023-05-05T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 3, Issue 1, 2023, p. 1-6.
N. M. Darsaliya, R. R. Farukhshina, Z. E. Saddik
Due to the emergence of new technologies that make it possible to obtain hydrogen from associated petroleum gas, it has become necessary to store and transport it. As a solution to this problem, the possibility of hydrogen transportation as a methane-hydrogen mixture was considered, i.e. natural gas with a certain hydrogen content. The article considers the issues of methane-hydrogen mixture (MHM) transportation through existing main gas pipelines at various percentages of hydrogen to natural gas. As an example, the Urengoyskoye field was chosen, where it is possible to produce hydrogen from the associated gas of gas condensate fields, and a section of the Novopskovskiy corridor, through which it is possible to transport MHM. In the work, the influence of the hydrogen content in the methane-hydrogen mixture on the gas-dynamic characteristics of the pipeline, mainly on the pressure and throughput capacity of gas in the pipeline, as well as the influence of its content on the operating mode of the compressor station and the power of the gas turbine, when using MHM for the station's own needs, was studied. The obtained results show an insignificant effect of the hydrogen percentage in the mixture on the pressure and throughput of the gas pipeline, which is a weighty argument in favor of the possibility of transporting hydrogen through existing gas pipelines.

Analysis of hydrocarbon solvents for the removal of various types of asphalt, resin and paraffin deposits

Khuramshina, Regina — 2023-06-21T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 3, Issue 1, 2023, p. 7-13.
Regina Khuramshina
In this work the physical-chemical properties of asphaltene-resin-paraffin deposits are studied. Their component composition was determined. The results obtained are the basis for the selection of effective solvents and the choice of the method of removing deposits from oil reservoirs. Two hydrocarbon solvents with the brands “TSK А” and “TSK B” were tested. The solvent ability of solvents was tested.

Development of a method for online control of plastic deformations of a tank wall and assessment of its residual life

Valeev, Anvar — 2023-06-21T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 3, Issue 1, 2023, p. 14-21.
Anvar Valeev, Emil Gaysin, Diana Khairetdinova, Nikita Atroshchenko
A method of operational control of the residual resource of the tank is proposed. As a tool, the measurement of deformations of the tank wall, the assessment of plastic deformations are used. To determine the deformation, it is proposed to use a light guide installed on the wall, with the help of which the change in the curvature of the wall is measured. A device prototype containing a light guide and the necessary electronics has been developed, and the dependence of the device readings on the curvature of the light guide has been experimentally determined. The simulation of the tank in the computer simulation program was carried out in order to compare the integral of the relative deformation over the height of the tank with the readings of the device. An algorithm for processing measurements of device readings and estimating the residual life of the tank is proposed.

Modern development of metamaterials for obtaining special electromagnetic, acoustic, mechanical and vibration-isolating properties

Valeev, Anvar — 2023-06-25T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 3, Issue 1, 2023, p. 22-33.
Anvar Valeev, Alexey Zotov, Aliia Siraeva
The article presents the history of the development of metamaterials, which begins with the development of metamaterials to obtain unique electromagnetic properties. The first ideas of such materials appeared in the XIX century. Such constructions make it possible to obtain a negative permittivity, and further the “invisibility effect”. The idea of creating a material with a given microstructure also makes it possible to obtain metamaterials with a negative Poisson’s ratio, acoustic metamaterials. Separately, it should be noted that such an approach makes it possible to obtain metamaterials with negative rigidity and vibration-isolating metamaterials. The article presents the author's design of a vibration-isolating metamaterial with quasi-zero stiffness. A demonstration prototype was made.

Overview of the prospects for the introduction of ultrasonic oil treatment in the main pipeline transport

Lisovskiy, A. — 2023-06-28T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 3, Issue 1, 2023, p. 34-40.
A. Lisovskiy, N. A. Atroscshenko, Yang Chen
This paper considers the most common methods of pipeline transport of high solidified oil existing at the moment. The effects of treating oil with magnetic and electric fields are given. The positive and negative effects of ultrasonic treatment in oil transport processes are considered. The totality and quality of the facts requires much more in-depth analysis on a number of issues in this area because with a lot of positive effects are present and negative, which do not allow to implement.

Analysis of methods for improving the efficiency of “Iceberg” gas air coolers

Arslanova, Alsu — 2023-06-30T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 3, Issue 1, 2023, p. 41-50.
Alsu Arslanova, Regina Farukhshina, Rimma Khatmullina
Russia has the largest volume of natural gas reserves in the world. Recoverable natural gas reserves amount to about 67 trillion cubic meters, according to the Ministry of Natural Resources and Environment of the Russian Federation for 2023. In recent years, the development of the Unified Gas Supply System has been growing rapidly. Since 2021 the Government of the Russian Federation has been actively introducing draft laws and regulations related to the scaling of the country’s gasification. In June 2021 came out the Federal Law No. 184-FZ, which instructed the Government of the Russian Federation to adopt regulations aimed at implementation of provisions of free gasification of the country [1]. In September 2021 there was issued Decree No. 1547, [2] approving the new Rules for connecting gas-using equipment and capital construction facilities to gas distribution networks, which introduces the concept of pre-gasification. It is worth noting that new gas mains, compressor stations (CS) are put into operation, active reconstruction of the existing shops with exhausted gas compressor units (GCU) is carried out. One of the most urgent issues of the gas industry today is the efficient use of energy resources. Besides using the energy of flue gases from gas turbine drive of GPA, energy at gas throttling at gas distribution stations and other methods of energy saving, the significant role is played by the effective operation of air coolers of gas (ACG), the operation of which affects the reliable transportation of gas in the main gas pipeline (MG). The paper analyzes the methods of technical condition of gas air cooling devices of “Iceberg” type operated at the production site of the booster compressor station of “Gazprom Dobycha Nadym” LLC. The thermal efficiency of air coolers with all fans turned on and off was determined for the coldest and hottest months of the year. The electric energy savings of the frequency controlled drive (VFD) were calculated.

Development of shock absorber with quasi-zero stiffness effect to reduce dynamic effects on pump unit

Gareev, Ainur — 2023-08-06T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 3, Issue 2, 2023, p. 51-58.
Ainur Gareev, Anvar Valeev
The article is devoted to the improvement of the vibration isolation and shockproof properties of the shock absorber used in the vibration isolation compensator system of the pumping unit (PU). The set task is to create an elastic damping system with the desired low (quasi-zero) stiffness, which makes it possible to reduce the detrimental effect of pumping unit vibrations both on human health and on the equipment itself. High internal dynamic (vibration) loads are the main causes of early failure of pumping units, which are transmitted to the equipment through pipelines and foundations, mainly due to various operational factors. A promising trend in increasing the operating reliability and efficiency of pumping and power equipment is the use of a vibration-isolating compensator system (VICS). To obtain greater efficiency of vibration isolation, it is proposed to apply a modern method of vibration damping – the use of elastic mechanical systems with quasi-zero stiffness. The damping devices with a quasi-zero stiffness effect were studied. An assessment of the operability and effectiveness of these dampers at oil and gas facilities was given. Based on the information studied, a new concept of a quasi-zero stiffness damping device is proposed. The method of mathematical analysis determined its power curve. A 3D model of the damper device was built using a simulation software. The functional check of the damper was performed with mathematical modeling carried out on the computing device with the help of a specialized Ansys software that allows performing a system analysis of an object using the finite element method. The following results were obtained: the design of the damper with the effect of quasi-zero stiffness allows to widen the range of basement load transmission coefficient reduction towards low frequencies. The low rigidity of the system at the operating point ensures low values of the frequency of natural oscillations, and, consequently, high vibration isolation qualities.

Analysis of methods for accounting for the amount of evaporation of petroleum products from the tank

Glushkov, Semyon — 2023-10-08T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 3, Issue 2, 2023, p. 59-66.
Semyon Glushkov, Anvar Valeev
In this paper, a detailed analysis was carried out of the methods that have been developed by various countries and organizations to calculate the losses of oil and petroleum products from tanks caused by natural factors. In the course of the study, legislative and regulatory documents regulating emissions into the atmosphere in various countries of the world were considered. Both positive and negative sides of the methods under consideration were identified, and based on the results obtained, a new and more improved method of automatic accounting of hydrocarbon vapors from tanks was proposed, the effectiveness and operability of the proposed method was proved. The study also formulated recommendations for future research in this direction, which may be useful for further improvement of methods for automatic calculation of losses of oil and petroleum products in various conditions.

Prediction and evaluation of polymer turbulent drag reduction efficiency based on BP neural network

Chen, Yang — 2023-10-30T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 3, Issue 2, 2023, p. 76-88.
Yang Chen, Minglan He, Meiyu Zhang, Jin Luo
In the process of oil exploitation and transportation, in order to effectively predict and control energy consumption for drag reduction of oil flow, in this paper a BP neural network was proposed based method for predicting and evaluating the turbulent drag reduction efficiency of polymers, which can greatly improve the current situation of relying on empirical formulas and low generality in polymer turbulent drag reduction efficiency prediction. Based on the experimental data sets of four commercial polymer drag-reducing agents FLOXL, М-Flowtreat, Necadd-447, and FLO MXA, obtained at different polymer concentrations, viscosity, density, and Reynolds number, a BP neural network has been established and the optimal number of neurons in the hidden layer was selected using the root mean square error (RMSE) value to obtain the optimal BP neural network prediction model. The BP neural network prediction models for the four polymer drag-reducing agents all have a good fit of 0.98 or above, and the R2 of the trained BP neural network for the Necadd-447 drag-reducing agents is 0.9949, which is the best among the four polymer drag-reducing agents. The BP neural network established in this paper can be applied to the turbulent drag reduction transport of long-distance pipelines for oil products to achieve the prediction of the drag reduction efficiency of polymer additives.

Experimental study on the rheological characteristics and viscosity-enhanced factors of super-viscous heavy oil

Chen, Yang — 2023-11-07T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 3, Issue 2, 2023, p. 67-75.
Yang Chen, Jin Luo, Meiyu Zhang, Minglan He
To reveal the viscosity-enhanced mechanism of super-viscous heavy oil and improve the recovery rate of super-viscous heavy oil, the four components, elemental composition, rheological properties, and effects of asphaltenes and resin on the viscosity of super-viscous heavy oil from well TH12434 in Tahe Oilfield, China have been analyzed from macro and microscopic perspectives by Anton Paar rotational rheometer, gas chromatography-mass spectrometry and scanning cryo-EM to solve the problems of poor fluidity and high asphaltene content. The experimental results showed that in the temperature range of T= 40-100°C, the viscosity of super-viscous heavy oil decreases sharply from 352000 mPa∙s to 1620 mPa∙s, and the super-viscous heavy oil exhibits clear thermo-sensitivity. With T= 100°C and shear rate ranging from γ= 0-800 s-1, the viscosity of super-viscous heavy oil decreases sharply from 45000 mPa∙s to 956 mPa∙s, and the oil sample shows typical pseudoplasticity. The baseline of super-viscous heavy oil analysis by gas chromatography shows too high, and more than 80 % of super-viscous heavy oil compounds have a matching degree of less than 70 % with standard compounds, indicating that the super-viscous heavy oil had poor heterogeneity and many impurities. It is observed by scanning cryo-EM that the micromorphology of super-viscous heavy oil is large granular, strong continuity, asphaltene micromorphology presents an obvious layered structure, the layer spacing is 637.7 nm, and its asphaltene molecules form an order-like or crystal-like association structure through several unit sheet layers, resulting in high viscosity of super-viscous heavy oil. Based on the analysis results of the influencing factors of the viscosity of super-viscous heavy oil, a theoretical basis for the selection of viscosity reduction technology for super-viscous heavy oil the efficient exploitation in Tahe Oilfield, China could be provided.

Vehicle suspension based on torsion bar and elastic hinge

Zotov, Alexey — 2024-02-14T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 4, Issue 1, 2024, p. 1-10.
Alexey Zotov, Anvar Valeev, Artem Tokarev
The article is devoted to the development of a vehicle suspension with a nonlinear characteristic based on a torsion bar and an elastic hinge with a given characteristic on the example of tracked vehicles for constructing oil and gas pipelines. The characteristic of the elastic hinge is such that when the existing torsion bar suspension and the elastic hinge are connected in parallel, the desired characteristic is obtained. For this non-linear characteristic in the static displacement region, low stiffness was obtained, but the total stored energy at the maximum deflection of the balance bar of the resulting suspension is greater than that of existing torsion suspensions. The smoothness of the tracked vehicles with a low stiffness of the suspension increases significantly. The calculation of vibrations of the proposed suspension under kinematic excitation was carried out. A harmonic function is considered as the trajectory of the profile; a function corresponding to a single obstacle and a function corresponding to an ascent to a ledge of a given height. The elastic hinge is a pneumatic spring moving between the guides of the design form. The force characteristic of the hinge depends on the shape of the guides and on the pressure in the air spring. The calculation of the circular shapes of the guides of the elastic hinge is given. The values of the forces arising between the pneumatic spring and the guides are determined.

Two-stroke engine with constant crank angular velocity

Zotov, Alexey — 2024-06-15T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 4, Issue 1, 2024, p. 11-21.
Alexey Zotov, Artem Tokarev, Anvar Valeev, Gulnaz Fatkullina
The work is devoted to the dynamics of a two-stroke engine. The engine used in sea vessels is considered. A new scheme of the crank mechanism of a two-stroke engine is proposed. An elastic hinge with a given angular characteristic (dependence of the restoring moment on the angle of rotation of the crank) is supposed to be installed between the strut and the crank. The work shows that with certain parameters of the hinge it is possible to obtain a constant angular velocity of the crank for any angle of rotation of the crank. Currently, flywheel inertia can account for up to 80 percent of all moving parts in an engine. Since the mass of engines is large, eliminating the flywheel from the engine design or reducing its mass may be a promising direction in the production of two-stroke engines. The proposed hinge is a structure in which an elastic element (spring or air spring) moves between circular guides of a calculated shape, resulting in a given hinge characteristic. In this work, an air spring was chosen as the elastic element of the hinge, since in this case it becomes possible to change the characteristics of the hinge by changing the pressure in the air spring. The shape of the guides is such that when adding the characteristic of an elastic hinge to the existing characteristic of the engine, an “ideal” characteristic of the considered engine with an elastic hinge is obtained, at which the angular velocity of the crank will be constant. When the angular velocity of the crank changes, a different characteristic of the hinge is required. In progress it is supposed to change the characteristics of the elastic hinge by changing the pressure in the air spring, which is the elastic element of the hinge. It turned out that by changing the initial excess pressure in the air spring it is possible to compensate for the change in the characteristics of the hinge required for the angular velocity of the crank to remain constant at any angle of rotation when its value changes. The results of these studies can be used both in the production of two-stroke engines and for any two-stroke engines.

Use of fibre optic systems for detection of small leaks on trunk pipelines

Shilov, Andrey — 2024-06-18T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 4, Issue 1, 2024, p. 22-29.
Andrey Shilov, Chingiz Nurmukhamedov
This paper is devoted to the issue of efficiency of application of fibre optic leak detection systems for identification of small leaks on trunk pipelines. The main methods of leak detection currently in use have been considered, and parametric and fibre optic LDS have been selected for comparative analysis. In the course of the research a model of product leakage from an underground oil pipeline equipped with a fibre-optic LDS was built in the COMSOL Multiphysics software package. The result of the simulation was the estimated time of leak identification by the fibre-optic system, which turned out to be much shorter than that of the parametric LDS. Compensable environmental damage for each type of system was then calculated, confirming the effectiveness of fibre optic LDS for detecting small leaks on trunk pipelines due to the significant reduction in compensable damage.

Analysis of dependencies for determination of friction head losses during pumping of oil with non-Newtonian properties

Nurmukhamedov, Chingiz — 2024-07-20T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 4, Issue 2, 2024, p. 30-38.
Chingiz Nurmukhamedov
An important task of increasing the energy efficiency of pipeline transport of oil with non-Newtonian properties is to improve the methods of hydraulic calculation of oil pipelines taking into account the complexity of rheological models of such fluids. Obtaining theoretical formulas for friction head losses in turbulent regime is not possible due to the complexity of the turbulent flow structure, so the methodology of hydraulic calculation is based on experimentally obtained dependences. In the article the dependences of friction head loss at turbulent flow of non-Newtonian liquid are analysed on the example of calculation for pipelines of different diameter. As the pumped liquid was considered heavy highly solidified Mangyshlak oil, transported by the main oil pipeline Uzen – Atyrau – Samara. The obtained results show that with the increase of the pipeline diameter the calculation error according to the analysed dependences increases, which is justified by the fact that the indicated dependences are obtained on the basis of experimental studies conducted on pipelines of small diameters.

Stress state and strength of welded joints with V-shaped elements

Gumerov, Aidar — 2024-11-08T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 4, Issue 2, 2024, p. 39-48.
Aidar Gumerov, Tagir Vafin, Viktoria Sokolova
It has been established that in the vicinity of V-shaped elements with a sharp apex, the stress field has a singularity of type σ→∞, which requires the use of the concept of “stress intensity factor” in strength calculations. This need arose due to different dimensions of the SIF and fracture toughness. Special criteria for the destruction of structures with V-shaped stress concentrators have been developed, which include, as special cases, the criteria of classical mechanics and the criteria of fracture mechanics. An experimental test of the proposed criteria and calculation methods was carried out. The information obtained is useful for analyzing welded joints on main pipelines and other equipment.

Analysis and modernization of gas production systems from compressor station equipment

Galyaviev, Elnar — 2025-01-09T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 5, Issue 1, 2025, p. 1-10.
Elnar Galyaviev
Mitigating methane emissions into the atmosphere to reduce adverse effects on the environment and climate is a primary goal of the environmental strategies employed by PJSC Gazprom and the Russian Federation as a whole. Experts warn that the planet is confronting a critical situation due to greenhouse gas emissions. This study examines the most effective technologies currently available for recovering gas from compressor station equipment. Based on an assessment of their strengths and weaknesses, a new system known as the Mobile Ejector Unit (MEU) has been proposed. The MEU utilizes a two-stage jet ejector, with its key characteristics derived from calculations based on G.N. Abramovich's methodology. Additionally, the study presents modification schemes for the valve unit to facilitate the MEU's connection, as well as gas recovery schemes from the centrifugal booster circuit and the compressor workshop circuit. An analysis of evacuation times based on different recovery schemes was conducted, along with an economic assessment of the MEU's implementation efficiency. The findings indicate that this technology is both effective and adaptable, owing to its operational simplicity, cost efficiency, and mobility.

Nonlinear mathematical model and method of solving the problem of isothermal flow of real fluid in a pipeline with a damper

Khujaev, Ismatulla — 2025-08-13T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 5, Issue 2, 2025, p. 31-44.
Ismatulla Khujaev, Bobur Bakhtiyorov, Shakhzod Khojikulov, Nilufar Turopova
The article presents a mathematical model of isothermal movement of a real liquid along a relief pipeline. The pipeline is characterized by a constant diameter, length, resistance coefficient and variable height of the axis above the horizon. The model is based on the quasi-one-dimensional, nonlinear model of N.E. Zhukovsky and volumetric deformation of the transported medium. The initial conditions are the pressure and velocity distributions along the pipeline. The boundary conditions of the problem take into account the change in the mass flow rate of liquid at the inlet and the intensity of liquid withdrawal after the air cap filled with real gas. By introducing an auxiliary function, equations are compiled relative to analogs of counter-running waves. Nonlinear equations are solved numerically using the finite difference method, and nonlinear boundary conditions are implemented using the tangent method. The role of the air cap in the processes of transition from one operating mode by mass flow is analyzed.

Analysis of a mathematical model of an active convection hydroturbine used in microhydropower plants

Matqosimov, Muhammadsodiq — 2025-12-30T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 5, Issue 2, 2025, p. 11-18.
Muhammadsodiq Matqosimov, Abduhoshimov Muslimbek, Xodjimatov Muhammadbobur
The production and distribution of electrical energy remain among the most pressing challenges in modern power supply systems. To address this issue, the integration of renewable energy sources and the use of asynchronous generators in mini- and micro-hydroelectric power plants are being actively developed. Asynchronous generators possess several advantages over synchronous machines, including structural simplicity, operational reliability, and low manufacturing cost. From this perspective, the present research demonstrates that the application of asynchronous generators can significantly reduce operational costs while maintaining a stable and uncomplicated process of electricity generation. This approach will facilitate the broader implementation of micro-hydropower plants and contribute to the sustainable development of the national energy sector.

Experimental analysis of the process of purifying transformer oil from various impurities under the influence of a constant electric field and assessment of mathematically modeled results

Yusupov, Dilmurod — 2025-12-31T00:00:00Z

Liquid and Gaseous Energy Resources, Vol. 5, Issue 2, 2025, p. 19-30.
Dilmurod Yusupov, Bobomurod Avazov
This paper has examined the cleaning of transformer oil by using electricity field on a theoretical and practical basis. Scientific analysis was done on the physicochemical characteristics of the oil and the effects of impurities on the electrical insulation characteristics of oil. A mathematical model explaining the movement of impurities under the action of an electric field was constructed on the basis of which, the extent of oil purification was established. According to the carried out theoretical and practical studies, the efficiency of transformer oil purification by constant electric field was tested. Based on the findings of theoretical modeling, the level of oil extraction against mechanical impurities is 40, and the electrical strength of the oil is enhanced by 16 and based on the findings of experiments that are carried out under laboratory conditions, the electrical strength is enhanced by 21. Due to the comparison between theoretical and practical outcomes, the deviation of the electrical strength indicator of the oil does not exceed 5 % and this fact supports the validity of the theoretical model developed. It was also determined that the purification process is affected by environmental factors like temperature, humidity, strength of electric field and composition of the oil. Enhancing oil purified in constant electric field is one of the effective solutions to the enhancement of the reliability of transformers and their service life.