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The object of research is the welded knot made of dissimilar steels 12Cr1MoV and Di-59. Research methods are spectral analysis, microhardness measurements and X-ray analysis. It is established that the structural-phase nonuniformity, significant concentration fluctuations of alloying elements, the spread in values of microhardness and mechanical characteristics along the length of the pipe can cause significant value of internal macrostress that leads to the formation of the “flaw” defect type in the welding process. It is shown how to distinguish between flaws that have appeared on the stage of production from operating flaws.

An evaluation is made of the thermal energy consumed in the heat-technology production of solid composite fuel from low-grade organic raw materials. It is shown that the heat of decomposition of the organic mass and the combustion of the by-products of heat-technology may be sufficient to cover all the energy needs for processing peat, brown coal and wood chips. Producing solid composite fuel from sapropel requires external resources to compensate for part of the heat consumed. Calculations show that it is possible for the thermal processing of raw materials to proceed autothermally due to the heat of decomposition when the moisture content at the reactor inlet is limited: for peat it should be no more than 35%, 54% for brown coal, and 37% for wood chips. The low heat of decomposition of the sapropel organic mass means that its thermal processing cannot proceed autothermally.

This paper presents new approaches to solving problems of forecasting the life of heating surface of boilers, based on an analysis of internal structural stresses of the first and second kind that could affect the intragranular and intergranular strength and reliability of the pipeline in continuous operation by making it work without damage by preventing the disclosure of zone cracks.

The issues and current trends of research in the field of decentralized energy supply for the period up to 2030 were considered. The analysis of the cogeneration market in Russia was done. The questions of gasification and hydrogen technologies as applied to the market of cogeneration plants were elucidated. Promising technologies for autonomous decentralized energy supply and the evaluation of their applicability to small energy were presented.

Involving of local low-grade fuels resources in fuel and energy balance is actual question of research in the present. In this paper the possibility of processing low-grade fuel in the solid fuel composite was considered. The aim of the work is to define the optimal parameters for formation of the solid composite fuel. A result of researches determined that dextrin content in the binder allows to obtain solid composite fuel having the highest strength. The drying temperature for the various fuels was determined: for pellets production was 20-80 °C, for briquettes – 20-40 °C.

The purpose of this research is the conversion of different types of biomass into solid composite fuel. The subject of research is the heat conversion of biomass into solid composite fuel. The research object is the biomass of the Tomsk region (Russia): peat, waste wood, lake sapropel. Physical experiment of biomass conversion is used as method of research. The new experimental unit for thermal conversion of biomass into carbon residue, fuel gas and pyrolysis condensate is described. As a result of research such parameters are obtained: thermotechnical biomass characteristics, material balances and product characteristics of the heat-technology conversion. Different methods of obtaining solid composite fuel from the products of thermal technologies are considered. As a result, it is established: heat-technology provides efficient conversion of the wood chips and peat; conversion of the lake sapropel is inefficient since the solid composite fuel has the high ash content and net calorific value.

Laws of the rate of carbon conversion in steam atmosphere at a temperature in modes of the catalytic low-temperature treatment of peat, brown coal, semi-coke from peat and brown coal are obtained by experiments. Increasing of the rate of carbon conversion in temperature range up to 500 °C is achieved by using of catalysts. The possibility of using results is associated with the burners, a working zone of which is porous filling from carbonaceous particles.

The relevance of the work is caused by reorientation of the modern power engineering to use of local low grade fuel resources. Some types of low grade fuels (peat, brown coal, sapropel, wood chips) are considered in this work. Thermotechnical characteristics of the investigated fuels and products of their thermal recycling are determined. Thermal recycling process is accompanied by release of fuel dissociation heat (0.33-3.69 MJ/kg). The results of thermal low grade fuel recycling are solid carbonaceous product (semi-coke) with a calorific value higher in 1.5-7 times than the value of natural fuels; pyrolysis resin with calorific value 29.4-36.8 MJ/kg; combustible gas with calorific value 15.16-19.06 MJ/m{3}.

In this article are described the prospects of peat and wood using as a raw material for gasification with producing of high potential synthesis gas. It is shown that the low-grade fuel recycling, in particular wood and peat makes a use of this energy sources a possible alternative to the using a more traditional coal and natural gas. The features of low-temperature pyrolysis are analyzed and computer modeling of this process at different conditions is conducted. The temperature influence of recycling to main parameters (calorific value, elementary composition of gaseous components) of produced gas is established.

The article describes computer simulation of the turbulent methane-air combustion in a fire-tube boiler furnace. Computer simulations performed for variants of once-through fire-tube furnace and reversive flame furnace. Options with various twist parameters of the fuel-air jet were examined. The flame structure has been determined computationally, contours of average speed, temperature and concentrations have been acquired. The results of calculations are presented in graphical form. Dependence of construction characteristics on vortex aerodynamic parameters was estimated. Turbulent combustion of natural gas in the reverse flame of fire-tube boiler was studied by means of the ANSYS Fluent 12.1.4 engineering simulation software.

Algorithm for estimating the efficiency of investment in innovative energy technologies has been used as a method of research. Two scripts of the project development (optimistic and pessimistic) were considered. Cost-effectiveness of replacing diesel power plants on the conversion units was determined.

In article the method for predicting the vortex formation in the dead-end furnace is described. Mass and heat balances of environment in the vortex are calculated using the computer simulation with ANSYS Fluent software. Engineering approach for quantitative analysis of singularities in the reversible flame is proposed. Assessment of vortices integral characteristics, including effects on the aerodynamics and heat transfer processes in dead-end furnace, is given.