№ 110(6), June, 2015
Public date: 30.06.2015
Archive of journal: Articles count 121, 265 kb
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AUTOMATIC FLAME CONTROL OF INDUSTRIAL INSTALLATIONS
Description
The article describes the modern problem of automatic flame control of industrial installations. The research of this problem is usually begun with the analysis of emergency mode of thermal generating units, divergence of parameters burning processes from accepted value. The most unfavorable factor for trouble-free operation of industrial thermal plants is the cyclical nature of the load changes energy-consuming devices with deep and rapid changes. The paper presents a study of physical factors affecting the stability of combustion in furnaces, the violation of which leads to abnormal flameout. It helps to equip thermal units with effective automatic protection
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THE SYSTEM OF WORKFLOW OF THE DEPARTMENT AT THE INSTITUTE
Description
The article describes the subsystem of workflow of the department at the institute “The calculation of teaching load”. As the process of calculation of teaching load is very complicated it has become necessary to make this process automatic. The mental card was developed where we can see the structure of the program for calculating teaching load. The subsystem has simple and understandable interface. The results of its work are represented in the form of filled blanks adopted by the academy in EXCEL. The created subsystem makes easier the teaching process of the department at the academy very much
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Description
The calculation of pumping equipment and piping network parameters is presented. The method of cutting impeller pump diameter for optimal performance of pump unit with piping system on efficiency value is shown. The case of operating the distribution network and pumping station with three pump units D1250-25 is considered. Procedure of construction of loss-of-head curves in pipes, determination of the actual operating parameters of a single pump unit, selection of pump impeller diameter for essentials is indicated. Four points for graphing such curves are presented. According to the first point the whole network is divided into sections with suction, pressure main pipelines and pipelines with changing water flow compared with the previous ones. The second point involves definition of the electrical resistivity of each site. The resistance of network analyzer is determined in the third point, the loss-of -head of the whole network is determined in the fourth point. The article presents the scheme of pumping station with three pump units connected in parallel and a distribution network (Figure1), loss-of-head curves in pipes regardless the number of working pumps (Figure 2), the order of constructing three loss-of-head curves with operating one, two and three pumps with normal and cut pump impeller diameter (Figure 3 ), the order of determination of the actual parameters of pump work characteristics according to combined characteristics of normal and cut pump impeller diameter ( Figure 4) In conclusion, it is stated that the question of proper definition of actual parameters of pumps and the support of these parameters in optimal mode remains open due to the lack of proper methods of constructing loss-of-head curves pipeline. Every similar calculation is preliminary and should be carried out in field conditions
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Description
This article presents main water supply systems and justifies the choice of direct flow of water supply system in the application of regulation of electric drive for pumps, which doesn’t have any tanks to create pressures required for fire-governmental purposes. This avoids interruption in the supply of reserve while water freezing. In the article the substantiation of the necessity of implementation of adaptive algorithm in modern-WIDE frequency converters by a substantiation of the number of stages of ratio control of voltage-frequency mains. It was revealed that the number of degrees of regulation of 10-12 gives optimum. Modern frequency converters allow you to change the regulation law, establishing 3-5 points of regulation. Therefore, the introduction of adaptive algorithm will reduce the power consumption of the electric drive of the pump of the water supply system. The article shows the simulation model of the "the converter frequency-induction motor," plots of the stator current of mains frequency and active power, surface speed and phase current when changing the voltage and frequency of the mains. These dependences confirm to have applicability of adaptive algorithm in the regulation of modern frequency converters with the skalar administration. Simulation model confirms the sub-physical experiments on a real motor and frequency converter with adaptive control algorithm. As a result of the selection of the parameters, we obtain the voltage reduction of the phase current, and reduce electricity consumption by 5-7%
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Description
The article contains an analytical overview of the causes of local washouts on hydraulic installations of Don highway networks. One of the major outlet structures of the main canal is the terminal resets in Sadkovskaya gully (Veselovsky reservoir 1115+79), with a maximum flow rate of 50 m3/sec, designed for irrigation and desalination of Veselovsky reservoir. To analyze the effect of the liquid on the bottom of the outlet structures we need to know the kinematic parameters of the liquid in the channel. Until now there are no universal correlations, which would allow calculating these parameters. The mathematical dependences allow analyzing the impact of water flow on the bottom of the spillway constructions of melioration canals. Modeling of local scour of channels is based on a thorough analysis of the causes of this phenomenon. The main ones are the kinematic parameters of the liquid, the speed and the propagation direction of fluid flow, structural features of the channel. The mathematical dependences allowed us to identify the following parameters that influence the degree of local scour at end spillway structures on melioration channels: the rate of flow, the degree of compression of the stream size, flow, shape, and movement of sediment, depth and shape of the supports in the plan and cross section, the shape of the hydrograph, the angle of the jet, duration of standing high water levels in Sadkovskaya balka, etc
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Description
The article deals with the results of research of acoustic and magnetic field influence on conductivity and pH value of hydroponic solution. For carrying out researches in this area the hypothesis of possibility of nutrient solution influence on ions by means of an acoustic and magnetic field is set up. A laboratory scale plant was constructed for a pilot study of the hypothesis. The solution was moved in the tube passing through a ferrite ring with winding. Thus, the solution was exposed to the influence of acoustic and magnetic field. The object of research was hydroponic solution of (NH4)2SO4; (NH4)2HPO4; K2SO4; Ca(NO3)2; MgSO4 in water having adjusted concentration and acidity. The solution was taken from the tank of laboratory scale plant by means of the pump, passed through the working area of the acoustic and magnetic device, filter, and then was poured into the tank, from which the sample for pH level changing was taken. The pH value was measured at the temperature of 22С by using electronic pH-meter KL-009(1)A. For control of instrument readings acidity was tested by universal test-paper. The initial pH value of solution made 5. As a result of acoustic and magnetic treatment of solution pH value of hydroponic solution increased from 6 to 6.9. The results show the possibility of pH value correction by small energy input
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Description
This article is devoted to solving the critical task of improving the reliability of the power systems for agricultural processing plants. The article’s material is exploratory in nature, reflected in the fact that the proposed mathematical models for the analysis of groups of high-voltage induction motors will allow to investigate various modes of symmetric groups of asynchronous motors more effectively. We present the analysis of the existing mathematical models of induction motors considering the design features of such machines that directly affect the dependence of resistance and inductance on the rotor current frequency. The assumptions taken into consideration to obtain a more accurate mathematical model of the induction motor are also formulated. The article provides a comparison of different reference frames used in the mathematical modeling of asynchronous motors. It is proved that the use of the generalized coordinate vector for mathematical modeling of asynchronous motors is the most optimal approach. The equivalent circuit of asynchronous deep-bar motor in generalized vector coordinates derived in the work is used for analysis of transient behavior as well as the steady state operation. The results of the study are suitable for transient analysis of electrical power supply systems of agricultural enterprises with large number of high-power electric motors, for example, CHP of sugar processing plants and grain elevators
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Description
The article presents a study of parameters and modes of operation of machines for soil cultivation. In determining the parameters and modes of operation of machinery for tillage we have applied the theory of similarity and dimensions of physical quantities. We have obtained the regularities of disclosing the relationship of the parameters from the medium to the energy characteristics of the process. As the initial data we used test protocols of machines for soil cultivation (Central - Black Earth, Kubanskaya, Sibirskaya, of North - Caucasion MIS, RosNIITiM) : KPI - 3.8, AРC - 3.9, AKV - 4, AKM - 6 - V, AMP - 4 APC - 4 A, AРC - 10 APR - 4.4, APU - 6.5 APSH - 6 , CNC - 6.0, CSТ - 3.8, APC - 4. We defined the formula оf dimension parameters and modes of operation of machines for soil cultivation and properties of soil (traction resistance, depth, width, speed, hardness of the soil, acceleration). Based on dimension theory we have received similarity criteria. Based on the correlation analysis and the least squares method we determined the nature of addiction and the coefficients for it. We have also received a graph for determining the operating modes and parameters of machines for soil cultivation
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Description
In the region, there is a problem of effective management of the pharmaceutical benefits under the benefit programs and the implementation of the therapeutic process. In health care in prescription health products of preferential category of citizens we have more than five different software developers involved that doesn’t allow controlling the prescription at all levels of health administration of the region. In order to form information flows into a single space it is necessary to have an integrated software product involved, both in the prescription, and in their service. The article presents a review of existing systems for issuing and servicing of preferential recipes, and prescriptions for controlled medicines, in the context of healthcare of the Krasnodar region, including considered the variety of products offered by different developers. The concept of integration of existing systems, which will allow overcoming the difficulties associated with fragmented solutions in automation preferential drug provision. For information exchange we encourage to use the XML format, examples of requests and responses in SOAP
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Description
PE2NT11 and chopped carbon fibers and PE2NT11 and modified carbon fibers composites were investigated. It was shown that the mechanical properties depend on the surface characteristics of fibers. It was found that laboratory and tube samples have some difference in mechanical properties that connected with specific distribution of fibers in samples
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