The paper contains analysis of reliability of non-restored passive reserved systems pertaining to control of technological processes. Criteria have been justified and methodology for optimum selection of reserved systems has been developed.

The paper is devoted to investigation of semi-conductor pulse step-up converter of constant voltage which is operating in the boundary-continuous current mode of a choke with digital control. The algorithms that have been developed make it possible to calculate the given value of coke current and sustain its saw-shape form with the help of digital control device. Values of feed back coefficients have been calculated by object coordinates at discrete character concerning change of control action.
The paper contains results of computer converter simulation in MATLAB model. The results prove that digital control with discrete period of 0.001 second can be implemented to step-up converter of constant voltage in the boundary-continuous current mode of a choke.

The paper contains formulation of basic theoretical principles pertaining to thermal protection of an oil transformer in accordance with classical theory of relay protection and theory of diagnostics with the purpose of unification of terminological and analytical information which is presently available in respect of this problem. Classification of abnormal thermal modes of an oil transformer and also algorithms and methods for operation of diagnostic thermal protection of a transformer have been proposed.

The paper gives complex evaluation of efficiency of incandescent lamps, luminescent and light-emitting-diode (LED) light sources in case of electric power price increase. On the basis of experimental table lamp electric power indices of light-emitting-diode (LED) light sources with equivalent luminous flux have been determined. Dependences of main indices of economic efficiency of various light sources on their operational regimes have been obtained and rate of influence on these indices of electric power price increase have been determined. Economically justified variants and conditions for application of various light sources have been substantiated.

The paper considers main advantages of half-wave electric power line as an interstate connection. Advantages of intersystem effect obtained due to this are given in the paper.

The paper confirms existence of economic (rational) operational zones of transformers in the form of dependences of the cited expenses on a load. The paper reveals that the best operational regime of a transformer corresponds to a minimum specific economic index that is cost of transform-science of economic energy.

The model for slag smelting regime has been developed. This model makes it possible to calculate phosphorus distribution according to slag composition, initial content of phosphorus in metal, temperature and time of lime efficiency. The model can be used for optimization of quantity and composition of slag , decrease of lime consumption and optimization of slag regime.

The existing conditions of heat supply operation create favorable possibilities for repeat involvement of large capabilities of low-potential heat at power objects of heat supply system in the fuel and energy balance of urban power engineering facilities and, first of all, it is possible due to introduction of power-saving heat-and-pump technology.

Diversity of conditions concerning organization of heat supply and sources of low-potential heat which can be used with the help of heat-and-pump technology in the system of centralized heat-supply reveals the necessity to take more serious approach to investigation of real possibilities of their application, owing to them it is possible to involve repeatedly used heat in the technological cycle of the urban power-and-heat generation complex.

Visualization of burning process in the closed vessel has been fulfilled with the help of method high-speed photography through a transparent glass. This method as an efficient means for investigation of fast processes permits to obtain a visual, convenient visual perception insight about the development of the burning process and understand peculiarities of the development of flame in the closed vessels.

The paper contains a description of an experimental stand and methodology for execution of an experiment on visualization of the flame development and measurement of main parameters of the burning process in a closed vessel that is in the simulating combustion chamber.

According to the obtained photos an analysis of form, structure and dynamics of flame front development has been carried out; some peculiarities and differences of flames of various fuel-air mixtures have been established and the paper proves an occurrence of the secondary glow during burning in the closed vessel.

Body of data obtained with the help of the visualization of burning process makes it possible to determine main parameters of the burning process. In particular, relation of the pressure developed in the chamber with the mass of burnt-out mixture has been investigated and dependence has been obtained that shows the law of fuel burning-out in the graphic form.

The paper evaluates additional errors while measuring oxygen concentration in a gas mixture by a solid-electrolyte cell. Experimental dependences of additional errors caused by changes in temperature in a sensor zone, discharge of gas mixture supplied to a sensor zone, partial pressure in the gas mixture and fluctuations in oxygen concentrations in the air.

Problems of rational fuel utilization becomes more and more significant especially for thermal power stations (TPS). Thermal power stations have complicated starting-up diagrams and utilization modes of their technological equipment. Method of diagram optimization of TPS equipment utilization modes has been developed. The method is based on computer analytical model with application of spline-approximation of power equipment characteristics. The method allows to economize fuel consumption at a rate of 15-20 % with accuracy of the predicted calculation not more than 0.25 %.

The paper contains a comparative analysis of turbo-driven variant application with TRB turbines and turbo-generator variant in the low power engineering. High efficiency of steam-turbine drive application with TRB turbines is proved by calculation which is made on the basis of a SE-1250-140 network pump at one of the boilers of the Republic of Belarus taken as an example. Calculation has been made for the following steam parameters: turbo-drive input – 12 kgs/cm and 250 and parameters behind turbo-drive – 1kgs/cm. Comparative analysis has been prepared on the basis of data presented by BelNIPIenergoprom in respect of regional boiler No.3 of Mogilev.

The paper considers a mathematical model of pulsation process of cylindrical underwater gas explosion products in the well at gas-impulse regeneration filters. A differential equation of the second-order with constant coefficients has been derived. A special calculation program has been developed to solve the equation. Expressions for calculation of maximum radius of cylindrical explosion chamber at the end of expansion process and pressure impulse in the first half-period pulsation.