Moscow Power Engineering Institute Research Articles

Syntactic Foams Efficiency with the Use of Various Microspheres for Heat Supply Equipment and Pipelines Heat Insulation

Syntactic foams are of interest to solve the problem of increase in the efficiency of heat supply equipment and pipelines heat insulation. The article analyses the efficiency of the use of various microspheres for syntactic foams when used for heat supply equipment and pipelines heat insulation. Moscow Power Engineering Institute has been conducting a large number of researches with the use of specific universal methods and the test stand which meets the modern requirements in order to determine the heat conductivity coefficient of various heat-insulating materials. These studies are designed to identify the impact of binding materials and microspheres properties over syntactic foams heat conductivity. The results of researches show that microspheres properties impact the heat-insulating characteristics of coatings.

Continuous emission monitoring and accounting automated systems at an HPP

Environmental and industrial emission monitoring at HPP’s is a very urgent task today. Industrial monitoring assumes monitoring of emissions of harmful pollutants and optimization of fuel combustion technological processes at HPP’s. Environmental monitoring is a system to assess ambient air quality with respect to a number of separate sources of harmful substances in pollution of atmospheric air of the area. Works on creating an industrial monitoring system are carried out at the National Research University Moscow Power Engineering Institute (MPEI) on the basis of the MPEI combined heat and power plant, and environmental monitoring stations are installed in Lefortovo raion, where the CHPP is located.

Электрические лампы с эффектом генерации в окружающую среду ионов и микроэлементов

In this article we consider multifunctional electrical lamps. In addition to producing required optical emission lamps sublimate ions and atoms of different trace elements to create ecologically healthy environment for production and inhabited placements. We present construction of electrical lamps with effect of sublimation trace elements and ions in environmental. That construction has been made by authors in Moscow Power Engineering Institute.

Developing dead-beat control in a valve electric drive

Problems of constructing high-speed control systems of electric drives with switch-mode power converters are discussed in the present paper. Historical aspects of the development of these theoretical issues at the Department of Automated Electric Drives of the Moscow Power Engineering Institute and their importance are discussed. The described converters are control objects of a discrete type that should be considered in the creation of control systems. It is shown that dead-beat control in such systems in the unconstrained case makes a finite number of discreteness intervals equal to the system order. Two currently important principles in construction of a dead-beat control system—namely, ones using predictive models in a real and accelerated time scale—are considered. Since the operation quality of such systems is determined by the adequacy of the predictive model of the control object, the approaches to creating the self-adjustment algorithms allowing one to correct the model in operation are considered.

Application of flap gas-dynamic bearing in turbine-generator units of low power

The article provides an overview of bearings used in high-speed turbomachines. It is shown that for low-power turbine-generator units in stationary or transport variant the most promising is use of flap gas-dynamic bearing, it is shown a comparison of different designs of flap gas dynamic bearings. The most detailed characteristics were given for flap gas-dynamic bearing with overlapping flaps developed in National Research University Moscow Power Engineering Institute, there are described the methods of their experimental study, shown operating and dynamic characteristics, as well as the range of products.

Modern state of cycle chemistry monitoring systems at thermal power stations according to the experience gained at the moscow power engineering institute and Element research and production center

Information about the development history of cycle chemistry monitoring systems is presented. The first pilot monitoring system at the Ryazan district power station is briefly described including the characteristics of the analyzers used in the system. The main principles for constructing monitoring systems are formulated. The characteristics of the monitoring systems that were designed and put in operation in the period from 2008 to 2011 are given together with a list of instruments and sample preparation devices used in them. The main advantages of modern analyzers used for chemical monitoring purposes are pointed out. Some problems affecting the operation of monitoring system equipment in the startup and transient operating modes of main power-generating equipment are specially mentioned.

Experimental studies of polydispersed wet steam flows in a turbine blade cascade

The paper describes experimental studies of water droplet motion in turbine cascades using laser diagnostic techniques (particle image velocimetry/particle tracking velocimetry). The investigations were performed at the experimental installation Wet Steam Circuit – 2 (WSC-2) at the Moscow Power Engineering Institute. The facility allows the study of the flow of superheated, saturated and wet steam over a broad range of velocities. The effect of the steam initial conditions on the behaviour of the coarse droplets downstream of a nozzle blade cascade has been studied for subsonic and supersonic flow. The variation of the average droplet velocities and angles across the blade pitch, and the droplet trajectories have been obtained. The relationship between the slip coefficients of droplets having minimal velocities in the blade trailing-edge plane, the initial steam wetness, and the axial distance downstream of the nozzle blade are suggested as the criteria characterising the coarse droplet motion downstream of the cascade.

Possibilities of cloud educational technologies in the study of physical chemistry

Opening of Mathcad Calculation Server (MCS) (http://www.vpu.ru/mas) at the Moscow Power Engineering Institute made it possible to create and implement an interactive reference book of physico-chemical quantities and thermodynamic database (http://twt.mpei.ac.ru/TTHB/1/HBThermValues.html) in the remote access mode in the educational process.Such authoritative electronic databases as, for example, the Database of Iftantermo, NIST Chemistry WebBook allow to obtain individual numbers or arrays of numbers characterizing the properties of substances and systems, but they do not generate functional and graphical relationships, which significantly reduces their educational opportunities. The peculiarity of interactive web-version of physicochemical quantities is its educational orientation: each Mathcad-document specifies by which experimental data the analytical dependence describing change of the investigated function was made, by which relations and how the investigated parameter is calculated, dependence diagrams are given, that allows to observe behavior of the searched quantity and current point on curve.

Estimating climate changes in the northern hemisphere in the 21st century under alternative scenarios of anthropogenic forcing

Possible changes in the climate characteristics of the Northern Hemisphere in the 21st century are esti� mated using a climate model (developed at the Obukhov Institute of Atmospheric Physics (OIAP), Russian Acad� emy of Sciences) under different scenarios of variations in the atmospheric contents of greenhouse gases and aero� sols, including those formed at the OIAP on the basis of SRES emission scenarios (group I) and scenarios (group II) developed at the Moscow Power Engineering Institute (MPEI). Over the 21st century, the global annual mean warming at the surface amounts to 1.2-2.6°C under scenarios I and 0.9-1.2°C under scenarios II. For all scenarios II, starting from the 2060s, a decrease is observed in the rate of increase in the global mean annual nearsurface air temperature. The spatial structures of variations in the mean annual nearsurface air temperature in the 21st cen� tury, which have been obtained for both groups of scenarios (with smaller absolute values for scenarios II), are sim� ilar. Under scenarios I, within the extratropical latitudes, the mean annual surface air temperature increases by 3- 7°C in North America and by 3-5°C in Eurasia in the 21st century. Under scenarios II, the nearsurface air tem� perature increases by 2-4°C in North America and by 2-3°C in Eurasia. An increase in the total amount of pre� cipitation by the end of the 21st century is noted for both groups of scenarios; the most significant increase in the precipitation rate is noted for the land of the Northern Hemisphere. By the late 21st century, the total area of the nearsurface permafrost soils of the land of the Northern Hemisphere decreases to 3.9-9.5 10 6 km 2 for scenarios I and 9.7-11.0 × 10 6 km 2 for scenarios II. The decrease in the area of nearsurface permafrost soils by 2091-2100 (as compared to 2001-2010) amounts to approximately 65% for scenarios I and 40% for scenarios II. By the end of the 21st century, in regions of eastern Siberia, in which nearsurface permafrost soils are preserved, the charac� teristic depths of seasonal thawing amount to 0.5-2.5 m for scenarios I and 1-2 m for scenarios II. In western Sibe� ria, the depth of seasonal thawing amounts to 1-2 m under both scenarios I and II.

Preparation of monodispersed spherical granules from different metals

Induced capillary breakdown of solid and hollow jets of molten metals, alloys, and salts with a melting temperature up to 1600°C is studied by experiment. Granulation technology is developed and specimens of solid and hollow monodispersed granules are obtained. Granules of lead and rare-earth metals have found application in cryogenic technology. Other areas for the use of monodispersed granules are considered. Substances that are in a granular, finely-dispersed condition, are used in various areas of science and technology. They may be granules of metals, alloys, or different chemical compounds. The efficiency of production processes using these materials depends markedly on granule parameters. Therefore an important task is preparation of monodispersed granules with identical and production properties. Use of these granules makes it possible to calculate quite precisely the characteris- tics of processes and to optimize them. Technology has been developed at the Center of High Technologies of the Moscow Power Engineering Institute (TsVT MEI) for preparing monodispersed granules, based on the physical effect of induced capillary jet breakdown (ICJB) (1). This effect arises with creation at the surface of a laminar jet of regular resonant perturbations for a given jet frequency (Fig. 1). The amplitude of these perturbations increases over the length of a jet as a result of which there is creation of a jet of monodispersed droplets ordered within space. During cooling of droplets in the time of descent in a heat exchange cham- ber conditions are created for their crystallization in the form of monodispersed spherical granules. The parameters (size, shape, structure, etc.) of these granules have a high level of uniformity. It is impossible to obtain this quality of granules using traditional granulation technology, even after sorting them with respect to shape and size. It should be noted that in prepar- ing monodispersed granules by ICJB the energy expended is less than in the case of the extensively used polydispersed break- down of a jet during granulation. This is connected with the fact that during ICJB a jet is an amplifier of harmonic perturba- tions created in its initial section. Forces of surface tension lead to an increase in the amplitude of these perturbations and breakdown of a jet into monodispersed droplets. In order to perturb a jet, it is sufficient to use a piezoelement with electric power supplied to it not exceeding 1 W. The reverse picture is observed during granulation by means of jet atomization. In this case surface tension forces plays a stabilizing role, and therefore in order to provide melt atomization it is necessary to affect it by a high-velocity stream of gas or liquid. The technology developed is ecologically clean and waste-free. The granulators created make it possible to prepare monodispersed granules from an extensive series of materials, including various metals and their alloys with a melting temperature up to 1600°C. A granulator (Fig. 2) is a closed circulation circuit, filled with helium and consisting of the following main components: droplet generator with a perturbation system and crucible, a heat exchange chamber with a granule collector, and a system for cleaning oxygen from helium. Emergence of the jet occurs under the action of excess gas pressure above the melt in a crucible. The magnitude of this pressure is controlled and

Development of silencers for suppressing noise emitted from heat-recovery boilers taking into account the attenuation of sound energy in their heating surfaces

A formula is proposed using which attenuation of the level of acoustic power in a heat-recovery boiler can be calculated as a function of the area of its heat-transfer heating surfaces. The silencers developed by specialists of the Moscow Power Engineering Institute for additional suppression of noise emitted from combined-cycle and gas turbine units equipped with heat-recovery boilers are considered.

Water chemistries at thermal and nuclear power stations: A new level of information support

Methods used by the Moscow Power Engineering Institute’s Department for Technologies of Water and Fuel in providing information support to the chemical departments of power stations in the field of organizing water chemistry of power units are described. Information is given on a new handbook on water chemistries at thermal and nuclear power stations and on the site supplementing this handbook.

The Moscow Power Engineering Institute (Technical University): from 1930 to 2010

The Moscow Power Engineering Institute (Technical University): from 1930 to 2010

Improvement of the main pump equipment used in large thermal power installations

The establishment and development history of the Moscow Power Engineering Institute’s Department of Hydromechanics and Hydraulic Machines, and the educational and scientific work presently conducted at it are briefly described. The research and design work aimed at developing the optimal construction of the flow path and blade systems for the stages of a feedwater pump with a useful capacity of 25 MW with the traditional one-sided admission of working fluid for power units designed to operate at supercritical steam conditions is discussed. A new alternative design solution for the cartridge of a super-powerful feedwater pump with the two-sided admission of working fluid is presented. The predicted possibility of achieving more reliable and energy-efficient performance of a feedwater pump equipped with such a cartridge is substantiated.

Specific features of systems for suppressing noise produced by the gas paths of power-generating boilers

Specific features of systems intended for suppressing noise produced by the gas paths of power-generating boilers and limitations that must be taken into account in constructing such systems are discussed. It is shown that the numerical method of simulating 3D flows can be used for development of systems for suppressing noise from gas paths. Examples of systems developed using this method at the Moscow Power Engineering Institute for reducing noise from the gas paths of the power-generating boilers Nos. 6 and 7 at Mosenergo’s GES-1 power station are given.

The influence of the maximally rapid heating and ignition of powdered Kuznetsk coals on the integrated operational efficiency of power-generating boilers

A technology for staged combustion of Kuznetsk coals is considered, the use of which allows the amount of nitrogen oxides generated in the furnace chamber to be reduced considerably while keeping a low level of incomplete combustion. The results obtained from practical implementation of the proposals suggested by specialists of the Moscow Power Engineering Institute on retrofitting boilers that fire Kuznetsk coals are presented.

Noise silencers on discharge lines of steam from power-generating boilers

The characteristics of well-known designs of steam noise silencers are analyzed. New steam noise silencers designed at Moscow Power Engineering Institute (MEI) are described, and results of tests of them carried out at different facilities are presented. It is shown that the MEI silencer can be used in a wide range of dump steam parameters and be applied in power units for both subcritical and supercritical steam conditions.

“Cloud computations” for chemical departments of power stations

The notion of “cloud computations” is defined, and examples of such computations carried out at the Moscow Power Engineering Institute are given. Calculations of emissions discharged into the atmosphere from steam and hot-water boilers, as well as other calculations presented on the Internet that are of interest for power stations, are shown.

Reduction of noise emitted from exhaust paths of gas turbine units equipped with heat recovery boilers

The values by which noise emitted from exhaust paths of different gas-turbine units equipped with heat recovery boilers exceeds the levels prescribed by sanitary standards are calculated. Measures to reduce noise emitted from the exhaust paths of gas-turbine units with heat recovery boilers are discussed, and design solutions developed at the Moscow Power Engineering Institute for suppressing this noise are described.

The innovation educational program of the Moscow Power Engineering Institute: New school laboratories at the Department of Automated Process Control Systems

A new set of school laboratories at the Moscow Power Engineering Institute’s Department of Automated Control Systems is described that are intended for training engineers specializing in systems for automatically controlling technological processes in power engineering. The principles and objectives of the educational process, and requirements for its methodical support are discussed.