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The paper investigates two different protective phosphate compositions for the chemical treatment of water and the use of them with a view to improve quality of “make-up” water in water heating systems. The research proved a positive effect of reducing the corrosive activity of water and the amount of scale.

Vertical supply of a wire in surfacing by two electron beams is proposed as a process for three-dimensional product growth. The numerical modeling of this process is outlined. In this approach, the product’s properties do not depend on the direction of growth; heating is uniform, with no shadowed areas; the process is flexible; and the heat supply to the metal may be regulated.

Based on the analysis of the Russian market of basic materials for phase-shifting heat accumulators (FPAT), including the issue of pricing policy, an attempt was made to reveal the dependence of the cost of a heat accumulator for a solar thermal supply system on operating and design parameters. In turn, to determine the latter, the method was used, which makes it possible to design FPAT with the given design and technological parameters, at a given minimum temperature of the coolant at the outlet of the accumulator, the known thermophysical characteristics of the coolant and heat storage material (TAM), including the phase transition temperature.

This article presents a brief history of the country’s heat supply system development. The types of heat supply systems are considered, their brief characteristics are given. Methods for determining the heat load for household needs (heating and hot water supply) of urban residents are presented. The study of the coolant temperature influence on the air temperature in the room was carried out. The study used an experimental-theoretical research method. As a part of the experimental study, the data of temperature measurements in one of the heating points in Tyumen were requested. Within the framework of a theoretical study, the air temperature in a living room was calculated, depending on the coolant temperature according to the schedule of the CHPP and according to the supply in the supply heat pipe. In carrying out the theoretical study, standard methods were used for carrying out thermal calculations of heat supply systems, statistical research methods, as well as standard computer programs. The need to regulate heat energy is determined and the types of regulation are considered. The analysis of the adopted temperature schedule of the CHPP was carried out and a comparison was made with the calculated temperature schedule. The solution of the equation for determining the air temperature in the room is given. The air temperature in the room depends simultaneously on two factors: the temperature of the heating medium and the temperature of the outside air. As a result of the study, the presence of a discrepancy between the temperatures of the network water supplied to consumers and the created air temperature in residential premises was determined. The intersection point of the calculated temperature schedule and the CHP schedule was determined. The necessity of observing the calculated temperature schedule of the central quality regulation has been substantiated. The necessity of heat supply at a constant flow rate of the heat carrier has also been substantiated.

Stability of a subsonic boundary layer with heat supply into its narrow band is studied. The maximum length of the stable boundary layer in the case of heat supply is found to be approximately three times smaller as compared to the case of a thermally insulated wall without heat supply. The frequency range of disturbances and their growth rates are approximately doubled. In contrast to the case without heat supply, three-dimensional disturbances are the most rapidly growing disturbances. In the case of a heated wall, the growth rate of disturbances decreases after heat supply into the boundary layer, which may lead to an increase in the length of the laminar region of the boundary layer.

The objective was to develop a mathematical simulation model of a pulsed spiral hydro-mechanical flow energy converter with a variable speed operating in a pulsed mode. This simulation model can be used for calculating the optimal parameters of such devices. The mechanical energy generated by pulsed liquid can be applied in the driving gear of mini-hydroelectric generators working without drops in water pressure, pumping stations and heat networks providing pressure reduction, as well as in heater fans operating in damp or explosion-hazardous facilities. Pulsed spiral hydro-mechanical energy converters can be used for converting the energy of a liquid flow into rotational motion, which can be further transferred to an electric generator or capacitor. In this study, using the example of a hydro-mechanical converter with a cone-shaped coil, the equations of torque depending on the change in the frequency of flow interruption, the moment of inertia and the resistance in the supports were obtained. Design charts were built for the torque of a hydro-mechanical converter with a cone-shaped coil for a number of coil turns equal to 4 pcs., square tube section 0.00011 m2, and the length of the initial round 0.176 m. The validity of the equations was confirmed by a physical experiment with sufficient accuracy. The conducted comparison of simulated and experimental values showed their agreement with an error of less than 5%. According to the simulation results, design parameters for different models have their own characteristics.

The main sources of thermal energy for the heat supply of cities and settlements are fuel-based thermal power plants and boilers. The article provides an analysis of the energy balance of a power plant in connection with the need to minimize the cost of fuel and electricity for heat supply. New analytical expressions comprehensively characterizing the efficiency of a power plant are developed. The analytical assessment of the impact of energy costs for the boiler needs on the energy balance of thermal power plant is made; methods for constructing schemes of the energy balance of thermal power plant and assessment of fuel efficiency in the boiler are designed. Attention is paid to errors arising from the use of the calculated values of air suction in the gas path of the boiler, and not the actual ones. Therefore, it is proposed to change the method of measuring heat loss with flue gases in order to eliminate or reduce the effect of air suction on the measurement results, taking into account the part of the flue gas heat received by the air in the air heater and returned to the boiler through the burner. The methods increasing accuracy of calculations of energy efficiency of the technological processes which are key in the centralized heat supply of the cities and settlements are developed.

The results of theoretical and experimental investigations of pressure distributions in a shear laminar flow between rotating eccentrically located cylinders are presented. It is shown that a change in the pressure in the slit gap is attributed to two mechanisms: to the "wedge effect" from the eccentrically located rotating tenon in the bearing and to the heat supply due to the adiabatic change of the volume, dissipative processes, and heat transfer.

The use of batteries in autonomous heating systems is a well-known method of equalizing heat loads, saving raw materials and energy resources. As a primary source of energy in such systems, they successfully use the heat of steam extracted from intermittently operating utilization plants, mainly converter gas coolers (JAGs) during the purging of the converter bath for steam accumulation using Roots batteries. At current rates and ranges of temperature change at the end of charging and discharging during operation of these systems, fatigue phenomena are possible in the metal case of the battery because of the existing deep “jumps” of temperatures with the formation of thermal stresses (overcooling) of its case, which causes a number of technical problems. To prevent this phenomenon, it is proposed to extract thermal energy from several such mass and heat exchangers when they are alternately connected to the evaporation circuit of the consumer. This method of heat selection makes it possible not only to avoid overcooling of the battery case, but also to improve the performance of the process as well. Based on the analysis of the formalized equation of heat supply dynamics to the consumer when the corresponding coolant is heated, it has been concluded that the efficiency of the pulsed mode of connecting batteries is effective. In doing so the temperature of the coolant varies exponentially. When implementing the proposed method, the heating of the next portion of the coolant is carried out under the conditions of the greatest temperature difference, which makes it possible to markedly intensify the process. It has been proved that the efficiency of the pulse mode is possible if there are already two or more batteries. It has been established that the duration of connecting each battery in a pulsed mode should not reach the duration of the transient heating of the coolant with the traditional method of heat extraction

By the three-dimensional model of heat transfer in the system "ground - horizontal ground heat exchanger - heat transfer agent", an analysis of the efficiency of the horizontal multi-loop heat exchanger, which is an element of the heat pump system, was carried out. Based on the results of numerical simulation, the time dependence of the heat transfer agent temperature at the outlet from the ground heat exchanger and the amount of heat extracted from the ground is determined. The results of calculations by the presented model are satisfactorily agree with the experimental data.

The paper presents the description and operating principle of energy-saving mini-grain dryers for drying small grain batches on farms using conductive and convective drying methods and the process of grain cooling with heat obtained from a traditional heat source and a heat carrier prepared with a solar collector or a charged heat storage. (Research purpose) To develop and study a compact energy-saving grain dryer, with a heat supply system based on both a traditional source and a heat transfer fluid heated by a solar collector or a charged heat storage. (Materials and methods) The authors have carried out experimental studies of the drying process of wheat grain to determine the effectiveness of the developed unit for grain drying; the main condition for saving energy has been taken as the minimization of the total unit cost of the evaporation of one kilogram of moisture. (Results and discussion) The authors have conducted a two-factor experiment to determine the main optimal parameters affecting the grain drying process - the speed of grain movement in the conductive chamber and the temperature of the heating surface of its casing based on the calculated mathematical model. In the first variant, the drying process was carried out only by the conductive method using the heat from a traditional energy source. In the second variant, the drying was carried out by successive use of conductive and convective methods, and the grain was cooled using both thermal energy received from a traditional source and solar radiation heat along with the heat of the spent heat carrier. (Conclusions) The study has revealed that the most effective option in terms of saving thermal energy is grain drying with the consistent use of conductive and convective drying methods followed by grain cooling. The heat supply of the drying unit was partially carried out by using the heat of solar radiation and the heat obtained from the spent coolant recycling. In this optimal variant, the heat consumption for evaporation of one kilogram of moisture from the grain is minimal and amounts to 1.53-2.50 MJ per kilogram with a grain movement speed of in the dryer of 0.007-0.011 m per second and a heating surface temperature of 85-91 degrees Celsius.

Experimental studies of heat transfer in the “emitter – air – heat supply object” system have been carried out in order to register the horizontal surface temperatures depending on the distance to the infrared heater. According to the results of the experiments, it was found that the temperature of the equipment surface areas influenced by the heater is significantly uneven. The temperature difference can reach 20 degrees, and an increase in the height of the object by 2 times increases its surface temperature by 67%. It has been established the need of considering the possible overheating of equipment located in zones heated by infrared heaters when developing systems for ensuring the regulatory thermal regime in large industrial premises.

Production processes sometimes are accompanied by the release of hazardous substances, the composition and volume of which is determined by the production technology. When designing ventilation systems for paint departments, special attention is paid to safety concerns, since all paint coatings are corrosive and flammable substances. Besides, solvent vapors are explosive. For local ventilation of painting chambers, it is rational to use safe exhaust systems with an ejector, which works sturdily, regardless of the release of flammable and explosive impurities. The ejector is simple in design and can operate in a wide range of changes in the parameters of the state of airflow. The model of the ejection unit is synthesized using the universal modeling package ChemCad, which contains a highly developed database of airflow parameters, which allows for solving various applied problems. Numerical modeling was carried out using the software package - FLUENT. In work, a calculation was carried out and a low-pressure ejector was designed for a typical painting booth. The calculation results are presented in the form of graphs and tables of pressures, velocities, flow rates in characteristic sections, pressure losses in the sections of the ejector installation.The ejection coefficient was also calculated.

The effect of TiO2 and the MgO/Al2O3 ratio on the viscosity, heat capacity, and enthalpy change of CaO&ndash, SiO2&ndash, Al2O3&ndash, MgO&ndash, TiO2 slag at constant heat input was studied. The variation of slag structure was analyzed by the calculation of activation energy and FTIR spectrum measurements. The results showed that the heat capacity and enthalpy change of the slag decreased with the increase of TiO2 content. Under constant heat supply, the fluctuations in slag temperature were relatively apparent, and the temperature of slag increased as the TiO2 content increased. The viscosity of slag decreased due to the increase in slag temperature. Increasing the MgO/Al2O3 ratio could decrease the temperature and viscosity of slag. The effect of increasing the MgO/Al2O3 ratio on the viscosity was more pronounced than the decreasing temperature caused by increasing the MgO/Al2O3 ratio. The apparent activation energy decreased with increasing TiO2 content and MgO/Al2O3 ratio. The Ti&ndash, O bonds formed with TiO2 addition, and the Ti&ndash, O bonds were weaker than Si&ndash, O bonds, which resulted in the decrease in heat capacity and viscosity of slag.

The result of improving the pasteurizer is a 6-fold decrease in the specific metal consumption by the device, in comparison with the basic design (26kg/m2versus 160kg/m2). The duration of heating and pasteurization of drinking milk at a temperature of 73...77°C while aging over 15...20s is 27.5s, which is 1.8times less. A reduction in the heat consumption for heating the apparatus is achieved, which is 1,372.8kJ (CPiPPU – Continuous "pipe in pipe" pasteurization unit), in comparison to the consumption by the basic pasteurizer, 8,448kJ. The uniformity of flow heating was established when its speed changes from 0.03 to 0.40m/s for various heat supply techniques; under the condition υ=0.4m/s, a temperature drop is ensured: at internal heating ‒ 1.4°C; in the basic design with external heating by a hot heat carrier ‒ 2.7°C; and in the proposed CPiPPU with double-sided heating ‒ 0.5°C. The comparison of heat supply techniques confirms the heat exchange efficiency of raw material processing by CPiPPU while ensuring a minimum temperature drop. The improved continuous pipe-in-pipe pasteurization unit based on the double-sided heating by a flexible film resistive electric heater of the radiating type (FFREHRT) is resource-efficient and can be used to heat food raw materials in the temperature range 15...110°C

An increase in clearance space between the rolled Ti + 2B strips was found to increase the burning velocity of double-layer Ti + 2B sandwiches. This was explained by additional heat supply to the reaction zone by a flow of hot gaseous products.

The limits of the ability of a distillation system to seperate a binary mixture are considered for two different cases. In the first case the heat supply solely takes place at the column bottom and the heat removal at the condenser. In the second case the heat supply and removal is distributed over the column height. For both cases, the limiting column capacity and the minimum heat consumption are related to the external stream compositions and to the heat and mass transfer coefficients.

Objectives The aim of the present work is to carry out mathematical modelling of heat exchange in rough flat channels and round pipes with rough walls during one-sided heating. Methods The calculation was based on the superposition principle of turbulent viscosity. The solution of the problem of intensified heat transfer in a flat channel and in a round tube with rough walls was obtained using the Lyon's integral. Results A methodology for the theoretical computational heat exchange determination for flat rough channels and round pipes with rough walls during one-sided heating is developed, in contrast to existing theoretical approaches, on the basis of the principle of full viscosity superposition in a turbulent boundary layer. The analysis of the calculated heat exchange and hydraulic resistance values for flat rough channels and round rough pipes under one-sided heating shows that the increase in heat exchange is always less than the corresponding increase in hydraulic resistance, which is a disadvantage as compared to the channels with turbulators, all else being equal. The results of calculating the heat exchange for channels with rough walls at one-sided heating in an extended range of determinant parameters differ significantly from the corresponding data for channels with turbulators and are used to determine the level of heat exchange intensification. Conclusion An increase in the calculated values of the relative average heat exchange Nu / NuGLduring one-sided heating for flat rough channels and rough pipes having very high relative roughness values is significantly affected by both an increase in the relative roughness height h/R0 and an increase in the Re Reynolds number. The main advantage of solutions for averaged heat transfer for rough flat channels and round pipes under symmetrical thermal load, obtained according to the developed theory, is that they allow the calculation of heat exchange in rough pipes to be made in the case of large and very large relative heights of roughness protrusions, including large Reynolds numbers, which is typical for pipes of small diameters and narrow flat channels. An increase in the relative heat exchange in air due to an increase in the relative height of the roughness or the Reynolds number is accompanied by an even more significant increase in the hydraulic resistance. Calculated data on averaged heat transfer obtained in the work indicated that in the range of determinant parameters for flat rough channels with one-sided heating, the average heat exchange is lower by (4  10)% as compared to round rough pipes, all other things being equal.

The article shows the results of mathematical simulation of convective turbulent heat transfer in the closed domain with heat-conducting walls and the source of heat emission. The system of equations in the model of thermal conductivity for the solid walls and Navier-Stokes equations for gas are solved. The article examines the possible versions of the calculation of the turbulent regime in the geometrically simple air region by means of conducting the simulation within the framework of algebraic models (Van Driest and Prandtl-Reichardt), and k-? model. On the basis of the obtained results the authors made a conclusion about the possibility of applying the algebraic model of Prandtl to describe the integral characteristics of turbulent flows in the conditions of natural convection in a geometrically simple area when the air heated by the heat source is moved by the lifting force. Besides, the temperature fields for a typical real object of heat supply are simulated in the article. The values of the dimensionless heat exchange coefficient at the air-wall interface are determined. The comparative analysis of two quite significantly different approaches to determine the average temperature in the heated room, i. e. the traditional balance approach and the approach based on the considered system of partial differential equations is executed. It is concluded that the balance models of the calculation of the temperature regime can adequately describe real temperatures of heat supply objects only for very large values of the characteristic times of the processes in question.

Some problems of supercritical fluid dynamics and heat transfer under various gravity conditions are solved experimentally and numerically. Ground-based experiments coupling with numerical simulations are performed to investigate dynamic and thermal effects in supercritical fluid subjected to heat supply. Numerical simulations of the piston effect and thermal gravity-driven convection in the fluids with variable physical properties are carried out. The effect of variability of properties caused by density and temperature inhomogeneities on the rate of the piston effect and convective patterns is discussed.

Corrosion investigation and reliability analysis of a family heat supply system has been carried out. Results indicate that the smoke emission steel pipe mainly suffers the corrosion at high temperature, and the corrosion components in the heat supply system undergo the atmospheric corrosion attack in indoor environment. Besides, safety and reliability related corrosion factors include water temperature, water oxygen concentration, pH value, carbon dioxide content, and chloride and sulfate ion in water have been discussed. It is concluded that the make-up water quality is crucial to the safety and reliability of the heat supply system.

The heat consumptions during fractionation of a binary mixture using different versions of heat supply to the column were compared. The standard version of adiabatic fractionation was compared with real versions that approximate it to reversible fractionation by using distributive heat supply (and removal) along the height of the column and increasing the number of theoretical stages. Adiabatic fractionation is characterized by the least heat consumption. This is explained by the increased internal energy saving in the column.

Boiling of cryogenic fluids is an important problem in superconductor technology, which becomes emergent in case an accidental, short-term and unsteady heating impulse appears. Here the process deviates from a standard scenario, approaching the crisis at lower heating. The present paper sheds light into the matter, aiming at the theoretical determination of the minimum critical heat flux required for the crisis to occur in the impulse mode. An analytical expression for the heat flux is derived and validated with the experiments on boiling in liquid nitrogen. Finally, a sensitivity study was performed looking at the influence of pressure, heater size and type of the fluid on the process.

Present work addresses technological properties of powder made from Jerusalem artichoke, formed by the method of drying with mixed supply of heat, compared to traditional convection. It is shown that polysaccharides in the composition of Jerusalem artichoke of MHS-drying undergo less crystallization and hence drying is carried out under milder conditions than these components during convection method. We established capacity for the dispersing of dried Jerusalem artichoke in a traditional ball mill depending on the duration, which makes it possible to obtain dried products for various technological purposes. We demonstrated a capacity to swell in the resulting powder made from Jerusalem artichoke, which predetermines the formation of advanced capillary-porous structure. Results of the tensometric method of studies revealed that the formed structure of powder made from Jerusalem artichoke of MHS-drying is characterized by small pores at temperature 50 °С and by 1.2...1.5 times larger – at 70 °С, which must be considered when they are rehydrated. We examined a complex of basic functional-technological properties of powder made from Jerusalem artichoke: coefficient of water absorption (CW), water-retaining (WRC), fat-retaining (FRC) and emulsifying capacities (EC). During mathematical processing of the results received, we obtained a conceptual model that describes a dependence of the comprehensive indicator of technological properties of powder made from Jerusalem artichoke (by the defined weight coefficients: for CW – 0.2; WRC – 0.2; FRC – 0.3; EC – 0.2) depending on the temperature of MHS-drying and dispersibility.

Objectives. The aim of present work was to carry out mathematical modelling of heat transfer with symmetrical heating in flat channels and round pipes with rough walls. Methods. The calculation was carried out using the L'Hopital-Bernoulli's method. The solution of the problem of intensified heat transfer in a round tube with rough walls was obtained using the Lyon's integral. Results. Different from existing theories, a methodology of theoretical computational heat transfer determination for flat rough channels and round pipes with rough walls is developed on the basis of the principle of full viscosity superposition in a turbulent boundary layer. The analysis of the calculated heat transfer and hydroresistivity values for flat rough channels and round rough pipes shows that the increase in heat transfer is always less than the corresponding increase in hydraulic resistance, which is a disadvantage as compared to channels with turbulators, with all else being equal. The results of calculating the heat transfer for channels with rough walls in an extended range of determinant parameters, which differ significantly from the corresponding data for the channels with turbulators, determine the level of heat exchange intensification. Conclusion. An increase in the calculated values of the relative average heat transfer Nu/NuGL for flat rough channels and rough pipes with very high values of the relative roughness is significantly contributed by both an increase in the relative roughness height and an increase in the Reynolds number Re. In comparison with empirical dependencies, the main advantage of solutions for averaged heat transfer in rough flat channels and round pipes under symmetrical thermal load obtained according to the developed theory is that they allow the calculation of heat exchange in rough pipes to be made in the case of large and very large relative heights of roughness protrusions, including large Reynolds numbers, typical for pipes of small diameters and narrow flat channels. An increase in the relative heat exchange in air due to an increase in the relative height of the roughness or the Reynolds number is accompanied by an even more significant increase in the hydraulic resistance. Calculated data on averaged heat transfer obtained in the work showed that in the range of determinant parameters for flat rough channels with symmetrical thermal loading, the average heat transfer is higher by (4.811.7)% as compared to round rough pipes – all other things being equal.

Microwave is thought of as a useful electromagnetic radiation tool because it is often used in real life as well as in a variety of chemical processes. Meanwhile, activation of metal-organic frameworks (MOFs), which must be essentially done to remove coordinating and pore-filling solvents before the use of MOFs for various applications, has been performed commonly with the methods of heat supply or solvent exchange. Here, we show a new methodological microwave activation (MA), realizing it with various MOFs such as HKUST-1, UiO-66, and MOF-74s. For instance, microwave irradiation to the MOF samples for 4-35 min leads to the complete activation of the MOFs without structural damage. As described below, we further demonstrate that the solvent-assisted MA, which is the MA process performed after the solvent exchange, can substantially reduce the time for the activation by 4 min.

The article shows the effect of the stage of internal combustion of biomass (pine sawdust) with insufficient and excessive heat supply. Thermochemical conversion of pine sawdust was carried out first in a dynamic mode to different temperatures of 280, 320, 360, 440 and 440 ° С, and then transferred to the isothermal mode for 1 hour. As a result, the following results were obtained: 1) Hydrogen does not form when heated to 280 ° C; it is formed in small quantities at 320 ° C. From a temperature of 360 ° C and higher, the formation of hydrogen becomes significant. You can also select two modes of education, which is especially noticeable at a temperature of 440 ° C. 2) In the cases of CH4, H2O, CO and CO2, three stages of formation can be distinguished: low-temperature, medium-temperature and high-temperature. For each selected stage, the corresponding kinetic coefficients were calculated.

Electrical energy in the thermal processes of agricultural production has a number of technical and technological advantages in comparison with other energy carriers. At the same time, electricity is the most high-quality but expensive type of energy. The effective use of electrical energy in thermal processes is possible with the implementation of all its advantages over fuel energy. This requires a system of technical, economic, and energy analysis and the selection justification of the most effective systems and technical means of heat supply of stationary agricultural technological processes. The chapter presents functional and technological schemes, physical models, the experimentally obtained dependencies, parameters, and operating regimes of the developed energy-saving electrical equipment and systems for the main thermal technological processes.

The article presents some results of studying the most optimal parameters of the displacer and the piston of a low-temperature engine with external heat supply to increase its efficiency when converting low-grade heat. The developed design of the engine does not have a displacer rod, which provides better sealing and reduces mechanical friction losses. Synchronization of the piston and the displacer movement is ensured by the permanent magnets interaction. The analysis of the results of computer simulation of the PV diagram with an increased diameter of the displacer in relation to the piston diameter plays a positive role in increasing the efficiency and power of the engine. Increasing the diameter of the displacer also leads to increasing the area of the PV diagram and its approach to the ideal thermal Stirling cycle. The simulation results show that increasing the diameter of the displacer above 17/1 does not lead to increasing the area of the PV diagram, and with a larger ratio, on the contrary, it reduces the parameters of the engine efficiency. Further increasing the diameter of the displacer is not advisable in terms of technical and economic ratios. The proposed engine with external heat supply is capable of converting heat from geothermal or industrial wastewater, as well as heated water using a solar collector.

The present paper is aimed at studying thermoelastic diffusion interactions in a thick circular plate of infinite extent and finite thickness subjected to an axisymmetric heat supply and a heat source in the context of Lord–Shulman theory of generalized thermoelastic diffusion. The upper and the lower surfaces of the thick plate are traction free and the chemical potential is assumed to be a known function of time. Integral transform techniques are used to find the analytic solution in the transform domain. Mathematical model is prepared for Copper material plate and the numerical results are discussed and illustrated graphically.

The effect of basic parameters of the channels of disk pulse devices on the heat exchange efficiency was studied both analytically and experimentally, especially in terms of pulse acting on the heat carrier. A methodology to determine the main parameters, namely the pressure and the temperature of the heat carrier as well as the pulse effect on the fluid, was proposed. The mathematical models of the effect of the structural and technological parameters of the channels in the disk pulse device on the heat exchange efficiency were developed. The models’ adequacy was proved based on a series of experimental studies involving devices with one-stage and multistage systems of pulsed heat carrier processing. This enabled the development, testing, and implementation of practical construction designs of pulse disk heat generators for decentralized heating of commercial and domestic buildings with one-stage and multistage systems of pulsed heat carrier processing. Taking into account the results of the mathematical modeling, the developed method of multistage pulse action was proved experimentally and implemented in regard to the structural design of a working chamber of the disk pulse heat generator. An efficient geometry of the working chamber of the disk pulse heat generator was specified for its further integration into the system of decentralized heat supply. One of the developed heat generators with the multistage pulse action on the heat carrier was integrated into the heating system of a greenhouse complex with a 0.86–0.9 efficiency coefficient.

Heat exchangers used in heating systems usually operate under conditions of variable flow rates and temperatures of heat carriers. However, the theory for calculating the variable modes of operation of such devices is based on the use of constant parameters of heat exchangers. At the same time it is clear that the parameter of the heat exchanger can be affected by all quantities that determine the change of the heat transfer coefficient. In addition, the groups of heat exchangers with a tied supply of heat, i.e. with redistribution of the heat flow in a variable mode of operation, are used. A new method for calculating the variable modes of operation of heat points with a tied heat supply has been developed. The method of mathematical modeling defines the dependencies that determine the change in the heat exchanger parameters in variable operating modes. The obtained expressions can be used to configure programmable regulators which will allow the correction of inefficient modes of operation of the heating system.