All articles - Energy and Fuels

The aim of the research work. Obtaining nanoscale structures and multilayer systems based on Mo and Si single crystals by epitaxy and ion implantation, studying regularities and elucidating the physical mechanisms of their formation
The object of the research work. Monocrystalline Mo and Si samples implanted by ions in a wide energy range (0,2 - 40 keV) and doses (D = 1014 - 101 cm").
Scientific novelty of there search work. The physical mechanisms for the formation of intermetallic compounds of the Nb + Mo type in the near-surface Mo layer during the implantation of Nb + ions in combination with annealing have been established and it has been experimentally proved that the formation of an intermetallic compound leads to the formation of the Mo subband of 4d electrons Nb below the Fermi level of Mo, which leads to a change in the density of the valence electron state Mo.
It has been experimentally established that the intermetallic compound is not formed in the implantation of Ba’ ions in Mo, but as a result of the decrease in the work function and the increase in the atomic density of the near-surface layer, the emission efficiency of secondary and photoelectrons increases 2 or more times, the main regularities of the formation of nanoscale phases and MeSi2 layers in the near-surface region of Si in the process of ion implantation and subsequent annealing are established, and methods for estimating their dimensions and determining the parameters of the energy bands based on studying the change in the intensity of transmitted light are developed;
The technology of obtaining homogeneous polycrystalline nanofilms of SiCb of various thicknesses (d~20-100A) and with a bandgap width of ~ 8.5 * 9 eV by the implantation of O2+ ions on the Si surface has been developed;
It is justified that the presence of several percents of accelerated ions (Eo = 1-2 keV) in the stream of sputtered metallic substances (Al) leads to the complete destruction of a thin oxide film on the Si surface and to the creation of a transition layer leading to an increase in the adhesion of metal to silicon substrates and a sharp decrease in the contact electrical resistivity;
a method for obtaining nanoscale two-layer systems of the MeSi2/Si/MeSi2/Si (Me-Co, Na) type with an integrated thickness not exceeding 40-50 nm; the thickness of the CoSi2 surface film is 3 * 5 nm; the thickness of the near-surface film is 10 * 12 nm, and the thickness of the Si film between these layers is 10-20 nm.

The aim of the research is increase of cooling effect in irrigation facilities on industrial enterprises cause of intensification of heat- oil mass transfer processes, reduction of hydraulic resistance, and development of mode conditions for increasing energy efficiency.
Tasks of research:
to develop mathematical model of energy efficient process for water cooling in tubular irrigators;
to develop computer program of dynamic process for technological cooling of water in cooling towers;
to perform adequacy analyses of experimental data of water cooling with result received by modeling on computers;
to develop the method of calculating polymer block of irrigation facility in cooling towers;
to develop scientific technical solutions on improving of industrial cooling towers with energy efficient equipment
The object of the research is fan cooling towers and their elements in the systems of recycled technical water supply of industrial enterprises.
Scientific novelty of the research is consisted of the following:
energy technological diagrams for recycled technical water supply with energy efficient tubular sprinklers made from composite polymeric materials in evaporative cooling towers were developed;
main energy-technological parameters of heat- oil mass transfer processes in energy-efficient composite polymer tubular sprinklers of the evaporative cooling tower were found;
the method of the water cooling process in tubular sprinklers taking into account turbulence and uneven distribution of phases was developed;
the algorithm for controlling the process of heat and oil mass transfer, water cooling in tubular sprinkler devices were developed;
the parameters of tube bundle hydraulic resistance dependent on the height of the sprinkler at various temperatures and air velocities in the cooling tower of cooling system were determined.
The structure and volume of the thesis. The dissertation consists of introduction, five chapters, conclusion, a list of references and appendices. The text of the thesis is presented on 120 pages.

The aim of the research work: The development of energy-saving modes of pumping machines of chemical enterprises - pumps and pumping stations, fans and compressors with adjustable electric drives..
Tasks of research:
development of energy-saving technologies of liquid transport by pumps and pumping units with frequency-controlled asynchronous electric drives;
development of energy efficient modes of operation of centrifugal turbo compressors with high-voltage synchronous motors, as well as techno-logical fans and their electric drives;
creation of energy-saving electric drive for fan load, providing the required value of the magnetic flux of the motor to minimize power losses in the electric drive;
development of methods for assessing the energy performance of pumping machines with adjustable electric drives, providing economical modes of their operation.
Objectives of the research arc regulated electric drives and pumping machines of chemical enterprises.
Scientific novelties of the research are following:
energy-saving modes of operation of pumps, fans and compressors, structural circuits for controlled electric drives and control algorithms have been developed;
the dependences of the power losses of a group of pumps on the frequency and the ratio of the number of pumps have been determined on the basis of ensuring the balance of water transmission in order to create an efficient pump station structure;
the scheme of energy-saving frequency-regulated asynchronous electric drive with an extreme control system for fan load has been improved;
the analytical dependence of the magnitude and frequency of the motor voltage, based on frequency control, has been developed to reduce the heating of the engine during the starting acceleration of the fan with a large inertia.
The structure and outline of the research work. The dissertation consists of following sections: introduction, four main chapters, conclusion, list of references, appendices, volume of the work is 110 pages.

Topicality and relevance of the theme of the dissertation. In Uzbekistan, using of solar energy (SE) is relevant, like to ensure energy security, and to improve the social and living conditions of the population. One of the most prepared area for large-scale using of solar cells in Uzbekistan is the system of hot water supply. For further expand the scale of the using of SE in this area in the first stage, it is necessary to have scientifically grounded information on their specific heat output and other technical, economic and environmental indicators.
The aim of the research is to development solutions for increasing the efficiency of using flat-plate solar collector (FSC)s in hot water supply systems (HWSS), optimizing their main thermal and engineering parameters, modeling the processes of thermal transformation of SE in them.
The scientific novelty of the research consists of following: - for the first time an approximate expression was found for determining the effective reduced coefficient of heat losses of the LAHP; - for the first time proposed and used in the calculation of a non-contact method for determining the average working temperature of LAHP; - proposed and implemented the methodology of complex optimization of the intertubular distance of sheet-paped LAHP.

The aim of the research is to improve the methods of mining analysis based on electromagnetic fields and to develop energy-saving technologies and devices for processing rocks.
Tasks of the research:
substantiation of the dependence of electromagnetic fields on the process of primary and secondary processing of materials;
improvement of methods for obtaining high-quality cement and ultrapure materials by dividing them on the basis of electromagnetic fields;
development of a multifunctional control device for technological processes of grinding, separation, enrichment and obtaining ecologically clean composite materials;
the development of a control system for an electromagnetic field device to reduce the energy consumption of technological processes for the enrichment of materials.
Object of the research are devices for processing technogenic and mineral resources in industrial enterprises, leading to energy and resource saving.
Scientific novelty of the research is as following:
the dependences of the interaction of charged particles in the electro magnetic field for the separation of the necessary elements from composite materials are justified;
methods for constructing equia-energy surfaces for grinding composite materials on the basis of the properties of the electro-magnetic field have been improved;
improved methods for obtaining high-quality cement and ultra-pure materials by means of the device, by enriching materials based on electromagnetic fields;
a multifunctional control device has been developed to improve the technological process of obtaining environmentally friendly materials, their grinding, separation and enrichment.
The structure and volume of the research work. The thesis consists of an introduction, four chapters, a conclusion, a list of literature, and applications. The volume of the thesis is 114 pages.

Research objective is improvement methods of rationing and forecasting parameters of power consumption, taking into account electric modes at the enterprises of ferrous metallurgy for increase efficiency of using electric power.
Research problems:
research electric modes and analysis the state of rationing and forecasting the parameters of electric power consumption at the objects electric steelmaking production enterprises of ferrous metallurgy;
improvement of the method for calculating scientifically based energy consumption standards for the release of finished products, taking into account the specifics of manufacture;
analysis of energy indicators and estimation of energy saving reserves;
the development of a method for calculating the optimal operating conditions for the main equipment of the electric arc furnace shop, taking into account the analysis of energy characteristics.
Object of the research is an electric steel smelting shop of JSC "Uzmetkombinat".
The scientific novelty of the research is as follows:
improved multilevel structure of the rationing of power consumption, taking into account the electric modes of steel smelting;
the methodical manual is developed, allowing to establish definition norms of expenses on kinds of energy at manufacture of metal rolling;
the scheme defining the predicted value of the specific expense of the electric power taking into account technology factors is improved;
developed an algorithm and a method for definition the optimal operating modes of the equipment of an electric steelmaking shop on the basis of the analysis of energy characteristics.
The structure and outline of the research work. The thesis consists of an introduction, four chapters, a conclusion, a list of literature, and applications. The volume of the thesis is 108 pages.

The aim of research work is to develop scientific proposals and practical recommendations on economic-ecological development of coal-mining branch of fuel and energy complex in the context of modernization.
Scientific novelty' of the research work is as follows:
proposed a step-by-step mechanism for improving the integrated economic and environmental activities of enterprises of the fuel and energy complex;
an integration system for integrating interactions between environmental programming subjects and the environment in the coordination of activities of integrated economic and environmental activities was improved;
a model for interaction of ecological, economic, social factors and maximization of economic-environmental efficiency of the complex usage of coal resources has been elaborated;
the organization-economical criteria for the development of the energy-chemical-resource complex was introduced.

The aim of research work is the development of physical mechanisms and new technical solutions for increasing the efficiency of photoelectric energy conversion in silicon-based structures, determining the features of promising widc-gap and environmentally pure structures.
Scientific novelty of research:
a new efficient design of a photoelectric module consisting of photoconverters with a vertical pn junction was developed. The photoelectric properties of the module have been substantially improved and a nearly threefold increase in economic efficiency has been justified;
scientifically justified to increase the photoelectric efficiency of a two-sidcdly sensitive photoconverter by balancing the flux density of light incident on the front and back surfaces with asymmetric light reflectors, and a new design of the photoelectric module is created;
the possibility of increasing the efficiency of obtaining photoelectric energy by forming nanoscalc structures in the emitter layer of silicon photoconverters is established;
the technology of obtaining promising hetcrostructurcs CujZnSnfSi-xSeJj/Si for the creation of photoconverters was first developed the elcctrophysical and photoelectric properties of the obtained samples were analyzed.