A. B. Kuvaldin

Moscow Power Engineering Institute (Technical University) · Insiitute of electrical engineeriing

A technology has been developed for melting a sprayed corrosion-resistant coating during induction heating of a steel cylindrical billet with the specified coating under rotational conditions. The current frequency and other parameters of the high-frequency induction unit were chosen to ensure maximum heat release in the corrosion-resistant coating...

Results are presented from studying EMF signals and their spectra using small rotating disks made of different metal alloys in the electromagnetic field of permanent magnets.

In installations with optical emitters, the indicator of the efficiency is the power factor depended on the electrical mode. In this paper, the object and subject of research are optical emitters affected the treated glass frosted surfaces. They are affected by electromagnetic radiation from optical emitters when powered by complex waveform current...

Using the complex waveform current (CWC) in electrotechnological installations (ETI) with radiators of different types allows improving their energy efficiency. A review of the literature sources revealed the theoretical prerequisites for the use of CWC in ETI with infrared radiators. The research allowed us to obtain the energy characteristics of...

The power factor is an important indicator of the installations efficiency with light and dark infrared radiators, their individual characteristics. The efficiency of installations depends on used electrical mode. In this paper, the object and subject of research are infrared ceramic lamps for heating, flexible heating tapes for electric heating sy...

A structural model of a high-frequency induction crucible furnace with a conducting ferromagnetic crucible is developed in the Simulink/Matlab environment based on investigations carried out by the authors. The inductor current was calculated using the inductor's resistance and inductance dependences on temperature, frequency, and current. An induc...

In order to select the effective operating modes of radiative electrotechnological installations, it is necessary to know the adjustment and spectral characteristics of the emitters, and the optical characteristics of the treated surfaces. In this paper, the radiation spectra of infrared emitters of different types in modes with a complex waveform...

In this paper there are offered calculated and experimental methods of simulating the high-speed modes of induction heating and designing the new inductor to provide the preset nonuniform thermal and thermostress state for cooled and uncooled blades of gas-turbine engine by changing the inductor width (specific power of induction heating). The pecu...

The joint work of heating tape and a dark infrared radiator at different electrical modes for getting positive technological and energy effects and indicators of electrical energy quality in the network have been investigated.

Influence of the reflected electromagnetic wave on the electrical characteristics of an induction crucible furnace with a conductive crucible is considered. The review and comparison of the known methods of calculation of induction crucible furnaces with a conductive crucible have been carried out. A mathematical model of an induction crucible furn...

The paper presents the results of studies of energy and technological parameters of the elements of heating flexible tape at different electrical modes: when powered by alternating current of 50 Hz; constant (rectified) current; current of complex form with a constant component and without it. The purpose of the work is to study the influence of el...

Currently, the effective technologies and modes development of electrotechnological installations is relevant. Power supply of electrotechnological and lighting load with calm character is usually realized from the busbars of a transformer. The effective operation mode of an electrotechnological and a lighting installation may be provide by the com...

The authors have been researching the effect of polyharmonic currents (complex waveform current) on the characteristics of different types of radiators for a few years. These researches have shown an increase in the energy efficiency of installations with dark and light radiators and the ability to control the harmonic composition of radiation. It...

Currently, the development of effective modes of mixed-load with a complex waveform current supply is relevant. In the article by the example of the physical model of a low-voltage electrode water heater and an energy-saving lamp, the work of mixed load after switching in the network is investigated. The purpose of the work is the processes researc...

Here we investigate induction furnace electrical parameters with lump loading changeable liquid melt level in the melting pot, and frequency converter with advanced energy data, with hybrid control of electrical reset mode with frequency controlling and frequency converter reconfiguration in conditions of profoundly changing loads.

The article presents the results of experimental studies of energy, technological parameters of the load in a steady state after switching in the network by the example of a mixed load with a power supply current of a complex shape connected to a power supply unit (on a physical model of an electric furnace of resistance to indirect and direct heat...

The bases of calculation of high-speed modes of induction heating taking into account restrictions on thermal stresses in heated products, as well as the results of computational and experimental studies of high-speed heating to improve the performance of plants and product quality. The features of high-speed induction heating and thermal stress st...

The mathematical electrothermal model based on a finite element method in the universal ELCUT package is developed for calculation of electric and thermal values of an induction crucible furnace. Electric characteristics depending on the frequency, temperature and current of an inductor are studied. The nonstationary thermal task is solved. Two ref...

At present, it remains urgent to develop effective electrode water heaters related to the need for more sophisticated technical means of electric heating of water for individual processes within enterprises. In the article on the example of the physical model of the low-voltage electrode of the heater there is described in the experimental study of...

Calculation methods for induction crucible furnaces with a conductive crucible have been reviewed and compared. The calculation method of electrical and energy characteristics of furnaces with a conductive crucible has been developed and the example of the calculation is shown below. The calculation results are compared with experimental data. Depe...

The research of electric and energetic characteristics of different versions of linear inductors for heating of steel ferromagnetic plates and tubes with the use of both industrial and elevated frequencies have been performed. The obtained results can be used in the development of pipeline and tank heating systems.

The physical models of the induction crucible furnaces with nonconducting crucible and conducting crucible were developed. Experimental study of the parameters of an induction crucible furnace for melting of ferromagnetic lumpy charge in ferromagnetic nonconducting crucible was made. Experimental study of the parameters of the furnace for melting c...

The changes in electrical parameters of the induction crucible furnace with a ferromagnetic lumpy charge are investigated. As the analytical description of the system furnace-lumpy charge ranging from the room temperature to Curie point is extremely difficult, the investigation is carried out by physical modeling. The results are discussed.

The changes of electric characteristics of induction crucible furnace in early period of melting the charge have been studied by using computer simulating. As a result the characteristics of active power in the charge, power factor, and electrical efficiency and other versus temperature and size of charge are represented.

A method for electrical and thermal calculation of pipeline induction heating is developed. The electric and thermal parameters of induction heating systems for thermally insulated pipelines by means of inductors installed above the thermal insulation are defined, in relation to the transporting pipe material and transporting fluid type. Recommenda...

The calculation algorithm of the melt surface shape of the induction crucible furnaces (ICF) taking into account the variable melt level in crucible is developed. The special-purpose software package for calculation of the height and melt surface shape in ICF is developed. The investigation results of the melt surface shape and its influence upon e...

The problems of calculation of heating units for ferromagnetic steel in weak electromagnetic fields are analyzed. Comparison of possibilities of induction, electrical contact and combined methods of pipe heating are provided. Special problems-heating system options-are considered: use of bimetallic outer conductors; use of increased frequency; effe...

One of fields of induction heating is realization of thermal processes in rotation bodies for carrying out tests and processes of disks aviation gas turbine engines and power installations on spin and specialized rigs. The induction heating allows to provide high speeds of heating and to receive the set non-uniform temperature distribution on radiu...

Three-dimensional models for calculation of electric and thermal parameters and electromagnetic fields at induction heating of rotating disks in program package ANSYS are developed. The results of investigations of induction heating of rotating disks of variable thickness and different inductors are presented. The influence of rotation frequency on...

A technique for determining the electrophysical properties of steel pipes is suggested when they are selected for use in induction and induction-resistance heating. By processing the results of experiments, the specific resistance and the dependence of the relative permeability of the magnetic-field strength on the pipe surface are determined using...

The high-speed modes of induction heating, thermal and thermostress distributions in blanks are calculated and investigated with use of the developed software package in view of influence of parameters of an electromagnetic field and properties of materials. The generalized dependences of high-speed induction heating of blanks and parts on the basi...

The calculation algorithm of the melt surface shape of the induction crucible furnaces (ICF) taking into account the variable melt level in crucible is developed. The special-purpose software package for calculation of the height and melt surface shape in ICF is developed. The investigation results of the melt surface shape and its influence upon e...

Summary The calculation method of the heat and electric characteristics of in- duction crucible holding furnace with take into account the variable melt level in crucible is developed. The structural model of the mixer is re- ceived. The model of the control system of the mixer with indirect esti- mation of the temperature is developed. The inducti...

Summary Methods have been developed for electromagnetic and electro- thermal calculation of coaxial induction-resistive heating systems for pipelines realized in form of application program package. Adequacy of the calculation methods is experimentally proven. At transportation of liquid products through pipe- lines in winter a problem appears rela...

Mathematical modelling of regimes of induction hardening of details in view of phase transformations, non-stationary thermal and thermostress state, residual stresses and fatigue has been carried out.

An inductive - resistive heating system is described, along with its applications. The mathematical model proposed for calculating the system's electrical and thermal parameters allows the mutual influence of the electromagnetic and temperature fields to be taken into account. The model is used for sample calculations of the system.

Two methods of calculating the electromagnetic field in ferromagnetic conducting medium taking hysteresis into account are proposed. The first method uses an electrical equivalent circuit of a ferromagnetic medium. The second method is based on a numerical calculation of an unsteady electromagnetic field.

Results from an analysis of active power losses in heating inductors with live parts of different profiles are presented. A mathematical body is developed for calculating the cross-section geometry of conductors at which the losses in the inductor are minimized. Recommendations on fabricating the conductors for the inductor winding are given.

Specific features of the operating conditions of high-speed induction surface hardening are considered. The surface hardening is carried out in steel heating until temperature exceeding the complete austenization temperature with following fast cooling. A package of computer programs is developed for calculating the parameters of the electromagneti...

Methods for calculating a high-speed induction heating of metal cylindrical blanks are proposed taking into account electrical, thermal-physical and elasticity-plasticity properties of the materials depending on the temperature and the restrictions by thermal stresses. An the limitations for the thermal stresses the limit values of the material yie...

Methods for calculating a high-speed induction heating of metal cylindrical blanks are proposed taking into account electrical, thermal-physical and elasticity-plasticity properties of the materials depending on the temperature and the restrictions by thermal stresses. An the limitations for the thermal stresses the limit values of the material yie...

The choice of induction heating regimes and inductor designs for modelling the thermostressed state of rotating turbine disks in the stand tests is considered. The results of numerical-experimental investigations are presented with the use of the finite element method on estimation of the influence of heating rate and current frequency on the resto...

This paper is the first attempt to consider the problem of using a current of the complicated shape in electrotechnology and contains more questions, than answers. Nevertheless, the experience gained during the use of such currents in electrolysis devices and described in this paper may facilitate the successful development of this advanced trend i...

The history of the faculty is described. A variety of research works conducted at the faculty are mentioned. In particular, the following works are pointed out: the development of automatic controllers for arc steel-making furnaces; control systems for vacuum-arc furnaces; devices of electron beam and plasma heating; calculation of induction heatin...

Special construction of multilayer inductor for decreasing reactive power and active losses is proposed. Inductor consists of two metallic bands with dielectric layer between them. Inductance of coil is compensated by the capacity between bands. Mathematical model of this inductor is realized as a programme package for calculation of distribution o...

A special design of multilayer inductor is proposed for reducing the reactive power and active losses. The inductor consists of two metal bands with a dielectric layer between them. Coil inductance is compensated for by the capacity between the bands. A mathematical model of this inductor is developed as a program package for calculating the distri...

Technical and economic characteristics, applications, classification, and basic trends of research are considered for devices used in induction heating of ferromagnetic steel. Some industrial types of units are described.

Trends in conservation of energy in induction electrothermal equipment are considered. The general characteristics, features, and some results are reported for studies aimed at reducing electrical losses through utilization of cryogenic cooling of conductors.

The results of numerical analysis of the electrodynamic forces acting on a multilayer inductor are presented. The influence of the number of layers and the geometric parameters of the system on the distribution of forces is investigated, with the aim of optimizing the construction of a cryoresistive inductor.

The use of cryoresistive systems in induction heating plants is considered and their potential economical and technical advantages as superconducting systems are investigated. The criteria for a cryoplant are studied and the corresponding investment and energy costs for a precisely defined crucible type of a furnace are computed.

An induction heater having a cryoresistive induction coil comprising an induction coil positioned in a cryostat filled with a cryogenic coolant having a temperature in the range of from 15* to 120* K., a heat-insulating element disposed around T charge to be heated, and a cooled baffle interposed between the cryostat and the heat-insulating element...

1. The Function diagram of a control system of induction crucible fur-nace (mixer) with temperature estimation on indirect parameters: 1 – the cru-cible, 2 – the melt, 3 – the inductor, 4 – the power supply, 5 – the voltage selector, 6 – the condenser battery, 7 – the PLC, 8 – the power sensor, 9 – the impedance sensor, 10 – the current sensor, 11...