A large number of power receivers with non-linear current-voltage characteristics with a pulsed mode of operation appeared in residential buildings, which leads to the generation of 0.38 kV higher harmonic current components into the electric network, large values of these harmonics lead to a deterioration in the shape of the network voltage curve. The purpose of the work is to study the harmonics of current generated by electrical receivers of residential buildings, and their influence on the coefficient of non-sinusoidality of the network voltage of 0.38 kV. It has been established that the greatest negative impact on the electric network is exerted by electronic devices with switching power supplies, such as PCs, laptops and netbooks, as well as dishwashers and LED lamps with a socle E14 and E27, whose total harmonic current component coefficient is 85% ≤ THDI ≤ 205%. In the Matlab Simulink program, a simulation model of a 0.38 kV network of a residential building is simulated, which allows the study of the total distortion coefficient of the current KI and voltage KU in the ASU. With the installed non-linear load power more than double the linear load, the coefficient of non-sinusoidality of the voltage in the network of 0.38 kV may exceed the values established by GOST 32144-2013.
Keywords: power supply system, electric network, quality of electric energy, voltage harmonics, current harmonics, electromagnetic compatibility, power receiver
The reliability of the solar heating system with solar collectors was studied using the logical-probabilistic method by building a fault tree. The fault tree was obtained by sequentially detailing the events associated with failures of the solar heating system, as well as its elements. Events were taken into account: conducting test diagnostics of elements of the power supply system, repairing failed elements, failure of elements, reducing the power of solar collectors due to a decrease in the intensity of the solar radiation. The events were divided into two groups: events in which there is sufficient intensity of solar radiation for the hot water supply from the solar collectors, as well as events when the heating supply cannot be provided only due to the solar collectors. The last group of events was divided into two subgroups, within events caused short-term downtimes (at the time of switching) and long-term downtimes (at the time of replacing or repairing a failed system element). Long shutdowns are associated with the coincidence of failures, repair or diagnosis of one or more elements of the solar heating system. Expressions are compiled to calculate the probability of long downtimes, the probability of short downtimes, the probability of failure due to a decrease in the intensity of the solar radiation, and the total probability of failures. As a result of substituting the values of the reliability indicators of the elements of the solar heating system, the value of the total probability of failure during the year is 4.03∙10-5.
Keywords: solar hot water supply, reliability, solar collector, failure cause, reliability modeling
The analysis of reliability of systems of an electricity transmission during which the main causes of the power outage in the consumer were identified. With the help of computer simulation, the results of operation of autonomous inverters are obtained with different number of voltage levels. The prospects of using the devices for balancing the incomplete-phase regimes on the basis of multilevel voltage inverters, which improve the reliability of power supply to consumers, are considered.
Keywords: analysis, stream of the failure, electricity, the balancing device, emergency operation, recovery time, failure, reliability, multilevel inverter, power line, user
The article discusses the development of a mathematical model in the deterministic form of recording the main dependences that determine the process of vaporization in a steam power plant to produce heat and electricity when used as a source of biofuel energy. Theoretically, the parameters of the working process of the installation were calculated; thermal efficiency of the turbine; heat useful used in the boiler unit; the efficiency of the boiler; the percentage of heat loss with exhaust gases; the estimated hourly consumption of solid biofuel; the annual amount of heat obtained by burning the mass of crop residues; the theoretical combustion temperature of crop residues; the actual steam velocity in the Laval nozzle; the heat loss in the nozzle, etc.in the course of calculations with the help of a multi-factor experiment, the parameters and the shape of the turbine blade used in the installation were obtained. Using the presented mathematical model given in the article and the data of the Federal state statistics service, we obtain the numerical values of the working process of the installation working on biofuel. For convenience, all the summary theoretical data of the numerical values of the basic theoretical dependences of the mathematical model of the working process of the layout of the steam power plant for heat and electricity was included in the table. Thus, theoretical studies show the possibility of producing electricity of the required quality using straw to produce high-pressure steam.
Keywords: mathematical model the working process of the pressure volume, a steam turbine,producing heat and electric energy, biofuels
The article substantiates the necessity of obtaining the dielectric properties of grain materials for studying the processes of microwave convective heat treatment of grain. The shortcomings of the existing methods for studying dielectric properties in the study of a ﬂuidized bed and suspended layer are described. A laboratory installation and an experiment on the investigation of a suspended grain layer are described. The results of experimental studies on the determination of the dielectric loss factor of wheat subjected to microwave treatment are presented. The results obtained for different material densities correspond to the general dynamics, but differ significantly in level. Thus, for a dense layer, which corresponds to a density of 660 kg / m3 in the humidity range of 11-30%, the dielectric loss coefficient varies in the range 0.18-0.42; for the fluidized bed (440 kg / m3) 0.06-0.15; for the weighed (220 kg / m3) 0,1-0,3.
Keywords: energy efficiency, the microwave field, thermal processing of grain, field modeling, direct heating, dielectric
The technique for calculating the basic geometric parameters of an LED lighting device is considered. The developed design allows to calculate the optimum parameters of the lighting device ensuring an even distribution of illumination with minimal energy consumption
Keywords: Illumination, LED lighting, surface contour, light distribution, surface plane, fluorescent lamps, lighting system, сartesian system, plane
The analysis of the state of transmission electrik lines, on the example, one of the districts of the Rostov region. The prospects of the use of symmetrization devices unbalance, what allows to increase the reliability of power supply to agricultural consumers.
Keywords: stream of the failure, electricity, the balancing device, emergency operation, recovery time, failure, reliability, multilevel inverter, analysis, power line, user.
The possibility of increasing the production of vegetables by different methods of preplant treatment of seed as an example of culture of a cucumber. The technique of obtaining a mathematical model describing the dependence producing vegetables on the methods of preplant treatment. The resulting mathematical model allows the company to forecast prices for the products and the distribution of income of the agricultural enterprise.
Keywords: Vegetables, seed mixture, pre-treatment, nutrient solutions, the electric field, productivity, mathematical model, normal distribution, the theoretical curve, the experimental curve, time series, yield and production
The study combined methods of influence on agricultural inputs in the process of post-harvest handling is largely associated with the development of instrumentation that allows to control the factors that affect the material. The article describes the results of theoretical and experimental studies to determine the electromagnetic field in a layer of grain material undergoing microwave treatment. In the field of theoretical research will come an exponential decay law of an electromagnetic wave in the material and the model built in the software package CST Studio. It is also a view of equipment designed for the experimental evaluation of the field intensity and its distribution pattern in the layer of the processed product. The dependences describing the measurement principle is implemented in this device. It provides an assessment of compliance with the theoretical and experimental methods of measurement. Increasing the accuracy of the experimental measurements can be achieved through the use of optical contact temperature sensors, as well as the use for the manufacture of the receiving materials with known data reliably dielectric properties in a given temperature range. The data obtained can be used for determining structural parameters of the microwave exposure zone, and for the development of control systems equipment. Finally, the conclusions based on the results of the work presented.
Keywords: energy efficiency, the microwave field, thermal processing of grain, field modeling, direct heating, dielectric
Research areas of the department cover the working out of energy saving measures and research investigations allowing to introduce into production:
rational algorithm of automatic temperature control system which allows to cut down expenses on fuel and energy resources consumption;
-energy saving and more reliable drive system of oil circuit breakers with a cylindrical linear motor;
-innovative lighting systems;
-discharge monitoring in aqueous medium;
-rapid early disease detection in animals via photoplethysmography and pulse curves analysis;
-automatic control system in frame area;
-methane fermentation of wastes, etc.
All these directions for research allow to increase competitive advantages of agribusiness enterprises of the Udmurt republic
Keywords: LED-light - emitting diodes; linear cylindrical induction motor; biogas units; automatic control systems algorithm; photoplethysmography; automatic temperature control system
There is the information of the use of belt electrostatic grain cleaner for the pre-sowing seed treatment with the purpose of their disinfection in this artcicle. The results of the treatment of seed mixture in electric field at the different variants of work conditions are presented. The specific expenditure of electric power on the percent of seed mixture disinfection was calculated.
Keywords: electric method, pre-sowing treatment, disinfection, electric field, belt electrostatic grain cleaner
An intensive method of disposal of cattle farms in a single cycle, to produce non-conventional source of energy (biogas) is proposes. Comparative characteristics of biogas at various ways of heating the biomass and the different types of bioreactor are reduced. A scheme of the physical model of the process of methane fermentation are considered.
Keywords: waste, technology, installation, heating, biogas, psychrophilic, mesophilic, thermophilic, temperature, energy source
In article the urgency of increase of overall performance of the electric drive of the oil switch in rural electric networks is proved. Possibility of application as the electric drive for oil switches of the cylindrical linear asynchronous electric motor is opened. In the mathematical form bases of work of electric motors of this kind are described. Results of calculations which confirm economic feasibility of application of the conclusions presented in article are resulted.
Keywords: the cylindrical linear asynchronous electric motor, the switch oil, the electric drive, overall performance increase
In the article the urgency of increasing the efficiency of the electric oil switch in rural power grids. Revealed the possibility of using as an actuator for oil circuit breakers cylindrical linear induction motor. In mathematical form describes the basics of electric motors of this type. Numerical results that confirm the economic viability of the application presented in this paper findings.
Keywords: Cylindrical linear induction motor, switch oil, electric, boost efficiency.
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Information is brought In article on using electro aerosol generator as humidifier of the air. They are Brought main formulas, allowing calculate the main parameters of the work electro aerosol humidifiers. The Offered design efficient electro aerosol generator, taking into account all particularities of the work electro aerosol generator in to quality of the humidifier.
Keywords: moistening, increasing to moisture of the air, electro aerosol, electro aerosol generator.