The paper considers a problem pertaining to determination of a statistical estimation of the half-hour load maximum of an industrial enterprise on the criterion of a minimum of total expenses. The estimation is made on the basis of fractile optimization characterizing a corridor width of value uncertainty of the half-hour load

The paper contains a proposal for classification of means used for higher dynamic stability of power transmission systems on the basis of a differential equation of generator rotor motion which makes possible to estimate efficiency of these means.

The paper considers methods for testing electric power equipment with reference to power transformers and electric direct current machines by measuring complex of their parameters. The above-mentioned methods have been realized in the devices DST-1M and IPEM, respectively.

An influence of inductive and capacitive elements included as components of low frequency filters in a measuring device on a value of an extra phase displacement between measured input currents and voltages being caused by them has been analyzed in the paper. The paper reveals that the extra phase displacement is initiated by oscillations of actual inductive and capacitive element values relative to their nominal values. Dependence of root-mean-square deviation of power measurement error due to phase displacement angle under load conditions at various tolerance values of the indicated elements and distribution of actual values of their nominal ones within these tolerances according to a normal low   has been calculated in the paper

The paper proposes a method that permits to synthesize rejecting filters with re-adjusted parameters in accordance with type-scheme functions. These filters are able to realize any given characteristics.

The paper contains commonly used and newly developed contactless forcing schemes in brake devices of asynchronous motors. Advantages and drawbacks of various contactless forcing schemes are presented in the paper. Conclusions are made in respect of prospective directions concerning development of contactless forcing schemes in brake devices.

One of the most efficient means of over-voltage reduction in arcing ground short-circuits is an application of   a nonlinear over-voltage limiter. It is necessary to take into account dynamic properties of the nonlinear over-voltage limiter in order to ensure authentic simulation of  over-voltage in the network A dynamic model of  the non-linear over-voltage limiter which takes a time lag constant   τ  into account during transition of the nonlinear over-voltage limiter into conducting state has been developed in the paper.

A problem pertaining to determination of the concentrated exergy of the asphalt concrete mixture is considered in the paper. The paper shows the possibility to use the concentrated exergy of the asphalt concrete mixture for qualitative energy evaluation of mixing processes.

An algorithm for selection of an energy efficient refractory lining has been developed on the basis of a ratio of summed-up capital expenditure and operating costs.

A non-linear problem of thermal conductivity in a layer of the fiber refractory lining has been numerically solved in the paper. The paper determines an actuality of the fiber refractory lining application at the temperature level of 55–75 °C  (on the average65 °C) on its external surface.

A mathematical solution of a refractory layer selection has been executed in the paper. The paper gives several variants of the arrangement  of three-layer fiber refractory lining.

The paper considers problems concerning optimization of a temperature schedule in the district heating systems with steam-turbine thermal power stations having average initial steam parameters. It has been shown in the paper that upkeeping of an optimum network water temperature permits to increase an energy efficiency of heat supply due to additional systematic saving of fuel.

 

The paper investigates influence of change in quality of superheated steam temperature regulations on service life of super-heater metal. А dependence between metal service life and dispersion value for different steel grades has been determined in the paper. Numerical values pertaining to increase of super-heater metal service life in case of transferring from manual regulation to standard system of automatic regulation (SAR) have been determined and in case of transferring from standard SAR to improved SAR. The analysis of tabular data and plotted dependencies makes it possible to conclude that any change in conditions of convection super-heater metal work due to better quality of the regulation leads to essential increase of time period which is left till the completion of the service life of a super-heater heating surface.

The paper describes analytical investigations that study relation of fuel combustion regimes with concentration values of sulphur anhydride in flue gases and acid dew point. Coefficients of convective heat transfer at internal and external surfaces of stacks have been determined in the paper. The paper reveals the possibility to reconstruct stacks while using gas discharging channel made of composite material on the basis of glass-reinforced plastic which permits to reduce thermo-stressed actions on reinforced concrete and increase volume of released gases due to practically two-fold reduction of gas-dynamic pressure losses along the pipe length.

The paper proposes a multi-section flash tank where heat transfer is intensified due to the following reasons:

– execution of separation process in the field of centrifugal forces;

– correct organization of input and output of superheated liquid from an operational chamber.