JVE International
Not a member yet
1200 research outputs found
Sort by
Transportation of hydrogen by main gas pipelines as a methane-hydrogen mixture
Get PDFDue 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
Vibrator with two impacting pairs, one of them in the position of equilibrium
Get PDFIn the dynamic processes taking place in manipulators and robots, impact interactions play an important role. Among them two sided impacts are important. In this paper investigation of dynamic regimes of a system with two impacting surfaces, one of which is in the position of equilibrium is performed. Dynamics in steady state regime for typical parameters of the investigated system having one degree of freedom is investigated. Displacements as functions of time as well as velocities as functions of time for various positions of the impacting surface are presented. Non symmetric impacts enable to reduce the dimensions of the vibrator and to achieve increase of effectiveness of useful impacts of a manipulator. Investigations of the conservative system as well as of the system with forced harmonic excitation are performed
Studying the impact of reservoir temperature, water salinity and CO2 dryness on CO2 injectivity during geological CO2 sequestration
Get PDFCarbon capture and storage (CCS) is proved to be effective measure for reducing CO2 emissions. whilst the world still highly depends on the use of fossil fuel energy, this method is necessary for reaching the world’s 1.5 °C goal. Saline aquifers among all possible underground formations are most common targeted ones for CO2 storage due to their frequent presence, and large storage capacity. However, this storage option suffers from sufficient well injectivity to inject large volumes of CO2 at acceptable rates through a minimum number of wells. The injectivity impairment/reinforcement happens through mineral dissolution, fine particle movement, salt precipitation and hydrate formation (known so far). Each of these mechanisms will be more dominant in injectivity alteration at different distance from the injection point depending on reservoir pressure and temperature, formation water salinity, rock mineralogy, and flow rate of CO2 injection as well as its dryness. In this study we have chosen a commercial software Eclipse 300 together with an open-source code to investigate the impact of formation characteristics, CO2 -Brine-Rock interaction, pressure, temperature as well as injection rate on injectivity alteration. The goal for this work is to provide a workflow which can help predicting injectivity alteration using the existing tools. Simulation results show that permeability is affected severely by salt precipitation during CO2 injection. Combined static and dynamic parameter study demonstrate that the injection rate plays a crucial role in size and expansion of CO2 plume as well as growth rate of dry out zone length, amount of salt precipitation and length of equilibrium region. The higher the injection rate, the quicker activation of the capillary and gravity force which leads to drag more brine to near well-bore resulting in higher volume fraction of salt precipitation. However, low injection rate could result in smaller CO2 plume, shorter dry out zone and longer equilibrium region in term of distance from injection point. Thus, optimizing the injection rate regarding reservoir parameters i.e., temperature, pressure and in-situ salinity, will lead to higher storage capacity as well as well performance and maintenance
Research on a double frame hydraulic press with PTS using winding steel wires
Get PDFThe desired preloading effect of a hydraulic press frame parts (upper/lower semi-circular beams and columns) with Pre-Tightening Stress (PTS) by means of Winding Steel Wires (WSW), which is directly related to the reliability and normal safe operation of the hydraulic press. The deformation of the Hydraulic Press Column (HPC) is an important indicator of the optimal preloading effect of the hydraulic press. As a technical bottleneck, the continuous cumulative deformation of a HPC under seven time-varying steps is critical issues especially in theoretically calculated for a 20 MN double-frame hydraulic press with PTS using WAW. A solid model with a PTS frame is pre-designed by 3D software, and two simulation methods, equivalent pressure loading and equivalent temperature loading, are used to simulate and analyze the continuous cumulative deformation of the HPC under each step in Ansys Workbench software. By comparing the deformation and error analysis in the three cases above, the feasibility of the two simulation methods is verified, which leads to the advantages and disadvantages of each method in order to guide the subsequent design
Prospects of robotics in food processing: an overview
Get PDFMechanical progressions in different spaces have widened the application skyline of advanced mechanics to an unbelievable degree. Packaging and processing are some of the important aspects involved in the food industry. As the global population continues to rise with increasing consumer demand for a wider variety of food products, food manufacturing is exploring various strategies, techniques, and methods to meet the demand and adapt to the change. Industrial robots are being integrated into every part of the food manufacturing sector to increase production rates and improve food quality and hygiene. The introduction of more stringent legislation is forcing the food sector to update its production process. On the vigorous review of 50 papers, this paper provides a comprehensive review of robotics in food processing and investigates its analysis in terms of the level of automation applied in various food processing industries. The expectation of food-Robo in the food sectors and robotics with an optimized protocol to fetch various ingredients and shape them into a final product
Improving ride comfort and road friendliness of heavy truck using semi-active suspension system
Get PDFTo enhance the ride comfort and improve the road friendliness of the heavy truck, based on the dynamic model of the heavy truck, the semi-active suspension system of the vehicle is proposed and controlled based on the fuzzy logic control and Matlab/Simulink software. The efficiency of the semi-active suspension system is then evaluated based on the indexes of the root mean square acceleration of the driver’s seat, the root mean square acceleration of the cab's pitching angle, and the dynamic load coefficient of the wheel axles. The results show that with the semi-active suspension system of the heavy truck controlled by the fuzzy logic control, the acceleration responses of the heavy truck and the dynamic forces of the wheel axles are greatly reduced in comparison with the passive suspension system under various operating conditions of the loads and speeds. Especially, with the semi-active suspension system controlled by the fuzzy logic control, the root mean square accelerations of the driver’s seat and cab pitch angle; and the dynamic load coefficient at 2nd axle of the wheel are clearly reduced by 23.7 %, 27.2 %, and 20.9 % in comparison with the passive suspension system, respectively. Thus, both ride comfort and road friendliness of the heavy truck are improved by the semi-active suspension system. In addition, the vehicle load insignificantly affects ride comfort. However, it greatly affects the road damage, especially with the half load condition of the vehicle. Thus, to improve road friendliness, the full load condition of the vehicle should be used
Automatic coordination control technology of interconnected medium voltage direct current (MVDC) distribution network based on frequency deviation
Get PDFThe automatic coordination control technology of interconnected medium voltage direct current (MVDC) distribution network based on frequency deviation is studied to improve the influence of frequency deviation on the operation of MVDC distribution network. Firstly, two regional interconnected MVDC distribution networks are built, and connected and operated in parallel with the AC power grid through the medium voltage single-phase AC port, to realize the interconnection of different regions of the distribution network according to the MVDC feeder. Through the mutual power support of each division of the distribution network, the frequency of each division of the distribution network is the same, and the frequency deviation of each division is reduced. According to the zoning frequency characteristics of the interconnected MVDC distribution network, the control strategy of the flexible interconnection device and the control strategy of the photovoltaic power generation system are combined to realize the automatic coordinated control of the frequency deviation of the interconnected MVDC distribution network. The experimental results show that this technology can improve the frequency deviation of the interconnected MVDC distribution network, realize the automatic coordinated control of the distribution network, and the fluctuation range of the tie line power deviation in each region decreases significantly
Modern biophysical view of electromagnetic processes of the phenomenon of life of living biological systems as a promising basis for the development of complex medicine: towards the concept of Bioelectronic Medicine
Get PDFThe publication of the results of a theoretical study on the conceptualization of Bioelectronic Medicine continues a series of articles on the role of electromagnetic processes in the implementation of the phenomenon of life. The authors, based on modern biophysical fundamental knowledge about the structure and functioning of the human body at the micro level of its structure (nanolevel and deeper) and the concepts of the Magnetoelectrochemical theory of metabolism, developed the main ideological concepts of the scientific direction “Bioelectronic Medicine” as a component for the further development of complex medicine. General scientific methods and theoretical methods were used in this theoretical study. The result of this theoretical research was the extrapolation of modern biophysical fundamental data on the structure of the microcosm of matter to medical knowledge about humans. It is proposed to call the resulting scientific direction the term “Bioelectronic medicine”. A conceptualization of the obtained fundamental ideas was made, three basic concepts and seven main aspects of “Bioelectronic Medicine” were formulated
Plane waves in an isotropic thermoelastic diffusive material using strain gradient theory
Get PDFThe governing equations of motion for an isotropic strain-gradient thermoelastic material with diffusion are formulated in context of Lord and Shulman generalization of thermoelasticity and are further specialised for a two dimensional plane. Plane harmonic solution of the governing equations in two-dimension suggests the existence of five plane waves which include four coupled longitudinal waves and a shear vertical wave. A numerical example is considered to illustrate graphically the effect of frequency, measure constant of diffusion, measure constant of thermo-diffusion, thermal relaxation time, diffusive relaxation time and the coefficients of hyperstress tensor on the phase speed and attenuation coefficients of the plane waves
Lithuania’s geo-energy landscape: a brief overview of CCUS, hydrogen, and geothermal
Get PDFLithuanian energy landscape is changing because of a strong push to reduce carbon emissions and reliance of fossil-based energy production. EU climate directive promotes investments into carbon capture and storage technologies along with renewable energy resource development. CCUS, hydrogen and geothermal are some technologies which could promote reduction in carbon emissions and along with reducing dependence on fossil-based energy sources. Lithuania already has large potential for carbon and hydrogen storage and in past had a working geothermal power plant for district heating. In this work we revisit the carbon storage potential in Lithuania subsurface and provide a high-level estimate of potential of generating hydrogen energy from depleted hydrocarbon fields using in-situ methods. We also evaluate the prospects of development of geothermal energy production from deep Cambrian reservoirs where temperature above 85 °C has been documented