Porous media can be used as heat transfer intensifiers in the petrochemical, refrigeration, food, energy, and other industries. In this paper, heat transfer in a porous medium with a pulsating flow is studied numerically. The simulation was carried out in the AnsysFluent software product. The porous medium was represented as a two-dimensional channel with square tubes. The working medium was air and water. The heat transfer and hydraulic resistance of a porous medium in a pulsating flow are determined for different porosity and fiber diameter depending on the Reynolds number, Prandtl number, frequency and amplitude of pulsations. It is shown that with an increase in the intensity of pulsations, an increase in heat transfer occurs. Heat transfer intensification essentially depends on regime and geometrical parameters. Several empirical correlation are proposed for calculating heat transfer and the degree of heat transfer intensification for symmetric and asymmetric flow pulsations. The thermal-hydraulic efficiency is determined for the same Reynolds numbers and powers for pumping the heat carrier in a porous medium with symmetric and asymmetric flow pulsations.

Keywords: heat transfer, pulsation flow, porous media, mathematical modeling, thermal-hydraulic efficiency

In this article, the object of study is a research drying chamber of a convective type, in the design of which a condensing heat exchanger based on a vapor-compression heat pump is introduced. The drying process of lumber refers to energy-intensive technologies, since the share of drying in the cost of finished materials reaches 50% [1]. In the presented experimental study, comparative results of two operating modes of the experimental installation are presented: standard (soft mode) and recirculation mode with a condensate dryer. The obtained experimental drying curves show that the cost of electrical energy, taking into account the option with a condensing heat exchanger, decreased by 7.75% compared to the standard.

Keywords: drying modes, drying, heat pump unit, heat recovery unit, material balance, heat balance, moisture content, heat consumption, experimental setup

The article considers the improvement of the centralized heat supply system (SCT) from Saransk CHP-2 by optimizing the calculated quantitative and qualitative parameters of the hydraulic regime due to circuit solutions (optimization of the thermal circuits of the CTP and etc.), including the distribution of thermal loads; the use of devices (installations) providing the expansion of the temperature schedule of heat supply to the network. This event will allow: to create the technical possibility of technological connection of a promising thermal load; to reduce specific fuel consumption by increasing the share of combined power generation at Saransk TPP-2; will ensure an increase in the utilization rate of the installed thermal capacity of Saransk TPP-2 to 45-50%.

Keywords: temperature chart; hydraulic mode; combined production; central heating point

The object of the development is an experimental installation with pulsed circulation of the coolant in the main circuit for its use as a hydraulic drive of a diaphragm pump used for pumping liquid in the secondary circuit, which increases the energy efficiency of the pump drive for small-scale energy facilities. An installation with pulsed circulation of the coolant with a diaphragm pump was developed, assembled and tested on the basis of a new design of the shock unit with a cam profile, which makes it possible to create an acceleration of the flow at the pump suction. As a result of the experiment, we obtained the dependence of the volume of the pumped liquid on the frequency of operation of the shock unit.

Keywords: energy efficiency, diaphragm pump, shock unit, pump drive, cam, fluid flow, fluid pressure, oscillation frequency

The paper provides an overview of the applications in central heating points (CHP) of technologies and equipment to improve energy efficiency and quality of heat supply from district heating systems. The main equipment and characteristics of the hot water supply system taken as an example of the central heating station "MGU" are given. Described is the method of choosing the heating circuit of the central heating station from the ratio of the maximum loads of hot water supply and heating. For the adopted example of a central heating station, based on the above characteristics, the main indicator of energy efficiency is the specific consumption of electrical energy for the transport of thermal energy. Factors that have the greatest impact on this indicator: coefficient of uneven consumption of "hot water"; quality of regulation of hot water supplied to the hot water supply network; precise control of the productivity of the boosting and circulation pumping stations. The standard total power of the pump drives has been determined to be 13.58 kW and the range of actual power is from 10.79 kW to 22.04 kW.To reduce the influence of factors in the control scheme, it is proposed to use flow (pressure) regulators to maintain a constant direct-acting pressure drop. Use the pressure (pressure difference) of hot water discharged to the DHW system and returned from the system as balancing forces for this regulator. The parameters of hot water of rational modes of operation of the hot water supply system from the central heating station "MGU" were determined: temperature of hot water at the outlet of the heat exchange equipment 75 ° С; hot water pressure at the outlet of the heat exchange equipment 45 m; hot water pressure at the inlet of the circulation pump 25 m. The implementation of the proposed option without the inertial control scheme for the temperature of "hot water" and the developed rational modes of operation of the hot water supply system, according to the assessment of efficiency indicators, will reduce the specific consumption of electrical energy in the central heating station by 28.4% from 0.631 kW * h / m3 to 0.452 kW * h / m3.

Keywords: central heating station, hydraulic mode, flow regulator, pump characteristic

This article presents the results of the analysis of factors influencing the burner device of heat generators, as well as methods for their selection. The results of an experimental study of the dependence of the efficiency of heat generators on the operating power of burners are presented. Recommendations have been developed for choosing a heat generator and a burner.

Keywords: heat generator, burner device, Gorenje mode, operating power, heat balance

The paper presents the results of numerical estimates of scattering of a dispersed medium (fog) using thermal and dynamic devices. Numerical modeling methods were used to obtain the results. On the basis of calculations, the use of different classes of combustible substances (kerosene, etc.) was analyzed for thermal dispersion, which is based on heating the air-drop medium to a temperature above the dew point, so that the drops that make up the fog evaporated. Technical devices of various capacities for pumping air from the zone of illumination, that is, using the method of dynamic scattering, are considered. The dynamic method is based on creating a flow of dry air located above the dispersed medium layer. In this case, the drier air coming from above or from the side causes the particles of the dispersed medium to evaporate, which leads to a decrease in its density.

Keywords: dispersed medium, low layered clouds, thermal scattering method, dynamic scattering method, calorific value of substances, zone of enlightenment

In this research the research problem of the liquid cooling system of supercomputer processors on nanomagnetic liquids by numerical modeling and the pilot study of processes of heat convection in the studied object is set. In article results of numerical modeling and the pilot study of process of the heat transfer are given in the heat exchanger of the liquid cooling system of supercomputer processors on the basis of nanomagnetic liquids, or ferroflyuid at influence of magnetic field impact assessment of magnetic field on the thermal resistance of the system and coefficient of heat convection the wall liquid Is made at different strengths of magnetic field. The numerical model of process of the heat transfer in the system the processor heat exchanger was investigated.

Keywords: processor, thermal resistance, Laplace equation, liquid computer cooling system, ferrofluid, nanomagnetic liquid, heat transfer, heat transfer coefficient

An approximate method for calculating the temperature field in solids heated by convection and radiation at the same time, when the thermophysical properties of the substance depend on temperature, is described. The method is based on the complex use of linearization functions and methods of numerical analysis. In the paper an example of calculation of radiation-convective heating of an unlimited plate, during which the heat capacity and thermal conductivity of the material change with temperature, is presented. The results obtained are in good agreement with the data of the finite difference method. The proposed method makes it possible to solve nonlinear problems of thermal conductivity with other boundary conditions, since the technique of solving such problems is not fundamentally different from one another. The article was published in the framework of the program of the International Forum "Victorious may 1945".

Keywords: temperature field,radiation-convective heating, thermal conductivity and heat capacity coefficients, linearizing transformation

This article presents the results of an experimental study of the deep cooling of natural gas combustion products in a condensation heat exchanger of a waste heat exchanger in a boiler house No. 12 at the Federal State Budgetary Educational Institution of Higher Education "National Research Ogarev Mordovia State University". The heat scheme of the boiler house with the flue gas heat exchanger provides the maximum continuous cooling mode. The study identified the factors that have the greatest impact on the efficiency of the heat exchanger-utilizer.With short-term operation of the boiler in the spring and autumn periods, the efficiency is more than 3%.

Keywords: burner, combustion mode optimization, heat utilizer, boiler room thermal circuit, boiler unit, flue gases, condensation, heat exchanger, cogeneration mode, cooled gases

In This study posed the problem of simulating the cooling system of supercomputers with a heat pump on the reverse Stirling cycle by numerical modeling of heat transfer processes in the object under study. The article presents the results of numerical simulation of heat transfer processes in the cooling system of processors of supercomputers with a heat pump on the reverse Stirling cycle. A numerical model of the heat transfer process was investigated. Using the method of numerical simulation of the heat transfer process, the dependences of the temperature delta, thermal resistance and the fraction of losses of the heat pump of the cooling system are obtained. The dependence of the ratio of the stroke of the piston to the diameter of the piston H / D of the heat pump has been revealed, taking into account the loss of the thermal resistance of the liquid cooling circuits and the elements of the design of the heat pump.

Keywords: processor, heat flow, thermal resistance, Laplace equation, heat pump, heat exchange, Stirling backflow, cooling system

The article deals with the main problems of obtaining experimental data on drying liquid dispersed products. The main difficulties of using a moisture meter to obtain kinetic curves of drying difficult-to-dry liquid materials are given. On the example of lignosulfonate drying curves of samples of liquid product in different conditions are obtained. Presented that the application of the proposed method of the experiment on the moisture meter does not lead to early completion of the operation of the analysis of the drying process.

Keywords: kinetics, moisture meter, drying, moisture, solvent, evaporation, lignosulfonates

Annotation: Several ways of utilizing the generated heat, produced by the final gas of boiler unit are analyzed in this article. The first method consists of implementing of heat pump into the process flow diagram of boiler-house plant. The second method encompasses the implementation of axifugal dry box into the process flow diagram. The dry box is implemented into the smoke removal system and also serves as axifugal smoke exhauster. The most widespread method is copious cooling of combustion product gas in steam condensing plants. The copious cooling of smokestack exhaust gases in steam condensing plants allows the full incorporation of sensible heat of smokestack exhaust gases (low heat value). The copious cooling allows the extraction of condensation heat of moistere vapours. The result would be the increasing ratio of utilization of boiler unit by 10-12 percent in optimum performance [ 5,6]. The implementation of steam condensing plant allows to decrease the concentration of nitrogen oxide in smokestack exhaust gases. The same effect can be achieved by implementation of heat pump plant. The efficiency of project implementation of steam condensing plant installation depends to a greater extent on the measure of the amount of hours of operation on peak capacity in recycling mode [6]. Therefore, the way of optimization of boiler flow diagram with the implementation of steam condensing plant, is suggested. This article contains calculations and technical and economic assessment of implementation heat-exchange facility, installed on bypass pipe of opetational block-modulator boiler-house plant with capability of 0,2 Gcal/hr, located in Spassk [4].

Keywords: Boiler-house plant, Steam condensing plant, final gas, heating agent, heat supply system, heat recovery unit, process flow diagram of boiler-house plant, optimization, boiler unit, smokestack exhaust gases, heat producing plant, condensing, heat-exchange

The scheme of calculation of nonstationary temperatures in the bodies heated by the radiation which based on the established dependencies between them is presented in the article. To study the process of radiation heating of bodies, the method of linearization functions proposed by one of the authors is used. The idea of the method is as follows. The linearizing transformation leads nonlinear boundary conditions to linear boundary conditions of the third kind. The solution of the linear problem in the stage of regular temperature regime is found by multiplying the corresponding solutions of one-dimensional transfer problems. After the transformations, equations are obtained that allow calculating the temperature fields in multidimensional bodies, if the temperature distribution along the coordinate axes or on the surface is known. There is no need to know the physical parameters of the material and the degree of blackness of the body surface.

Keywords: temperature field, radiation heating, multidimensional bodies, linearizing transformation, linear boundary conditions of the third kind

This article presents the results of an experimental study and evaluation of the application of a method for optimizing fuel use by the ratio of the power of a boiler unit in a block-modular boiler house and setting the power of a burner on the combustion steps. As a result of the study, the criteria for the application of this method to the existing block-modular boiler house, the factors having the greatest influence on the efficiency of the boiler units are determined.

Keywords: heat transfer intensification, optimization of fuel use, cogeneration mode, energy production, combustion mode, boiler, condensation, gas flow turbulization, waste heat boiler

In this paper, we propose a technique for calculation of the thickness. This technique is allowed to determine the thickness of a sleeping bag based on data on the equivalent coefficient of thermal conductivity of a sleeping bag package and data of heat production of person during the sleep. The values and trends in the variation of the relative discrepancy between the calculated and experimental thickness of the sleeping bags as a function of temperature are explained by the possible differences in the data on the thermal conductivity of the down, and by the necessity to introduce thermal insulation coefficients for individual parts of the body.

Keywords: Key words: sleeping bag thickness, down, thermal conductivity, thermal insulation

The article deals with the analysis of theoretical cycles of internal combustion engines. Presents Otto cycle, Diesel and Sabate-Trinkler. The theoretical cycle is a closed cycle occurring in the cylinders of the piston engine with its inherent features and assumptions. Each cycle is characterized by two main indicators, such as heat use and efficiency. In this case, the thermal utilization is determined by the thermal efficiency. The estimation of influence of thermodynamic factors on change of thermal efficiency for reception of the best efficiency and the maximum specific work of cycles is resulted. The thermal efficiency of the mixed cycle is obtained. The conclusions of the influence of the compression ratio on the thermal efficiency are presented. A comparison' of different theoretical cycles from the point of view of their cost-effectiveness and efficiency under the same conditions.

Keywords: internal combustion engine, ideal cycle, thermal efficiency, thermal processes

The article gives an overview of the ways to utilize the heat of the boiler exhaust gases. In conditions of actualization (both technical and economic expediency) of application of technologies for fuel economy and environmental protection, the use of aggregates based on the internal combustion engine and microturbines with the utilization of the heat of the cooling system and exhaust gases has found application. Deep cooling of combustion products of natural gas both in boilers (condensing boilers) and in special condensing heat exchangers (utilizers) makes it possible not only to organize the full utilization of the physical heat of the flue gases (the lowest heat of combustion of the fuel), but also to select the latent heat of condensation Water vapor. The coefficient of efficiency of the boiler-aggregate will be increased in this mode by 8-12%, provided that the boiler operates in the optimal mode. Cooling of combustion products also reduces the content of nitrogen oxides in flue gases, incl. With the use of heat pump plants. The efficiency of the implementation of projects for the installation of condensing heat exchangers depends to a large extent on the number of hours of operation at maximum capacity in the mode of deep utilization. In this connection, we propose a variant of optimization of the boiler room thermal scheme with the heat recovery of the flue gases.

Keywords: Heat recovery boiler, boiler house thermal scheme, optimization, boiler, flue gases, heat generating unit

A comparative analysis of the methods of heat engineering calculation and an assessment of the efficiency of heat exchange in frame-panel housing construction are presented.

Keywords: Skeleton-panel housing construction, air permeability, heat exchange efficiency, heat and moisture regime

The existing and promising methods of drying of coatings from organic solvents presented. The important role of the temperature of the drying kinetics, which determines the rate of chemical and rheological processes. Shown the crucial role of design and technology solutions. The main problem of experimental research, calculation and simulation, energy resource and environment in the development of processes and equipment for the evaporation of solvents and coating treatment is determined.

Keywords: kinetics, drying, solvent, mode, experiment, modeling, coating

The article considers the way of organizing the process of material drying from organic solvents. The typical kinetic curves, observed in the evaporation of solvents. Given received and the recommended equations for calculating the evaporation intensity and the surface temperature of the evaporation in the first period. The analysis of major scientific and technological problems arising in the implementation of new drying technologies.

Keywords: modeling, calculation, drying, solvent, kinetics, evaporation, energy saving

The article considers the experimental estimation of the heat transfer coefficient in a hybrid immersion cooling system with contact point cooling and dry zones. The change in the heat transfer coefficient is made through a change in the Reynolds number for the flow of the coolant in the immersion cooling system. The experimental investigation is carried out on the basis of a numerical simulation model of the process under study. As a result, the dependences of the thermal resistance of the processor-heat exchanger system on the heat transfer coefficient and on the Reynolds number of the turbulent flow were obtained, and the results with the simulation results were estimated. It is found that, with an increase in the Reynolds number, the heat transfer intensification is weaker than the theoretical one. The refinement coefficients for the case under consideration are found.

Keywords: processor, heat flow, thermal resistance, Laplace equation, turbulent flow, Reynolds number, heat transfer, immersion cooling system, immersion cooling system, cavitation

In this study, the task is to simulate the cooling system of supercomputers with a heat pump on the reverse Stirling cycle by numerical simulation of heat transfer processes in the object under study. The results of numerical simulation of heat transfer processes in the superheater processor cooling system with a heat pump on the reverse cycle are presented. A numerical model of the heat transfer process was investigated. As a result, the dependencies of the required thermal lift of the heat pump are obtained taking into account the thermal resistance of the system. The first liquid cooling circuit - the cold cylinder of the heat pump and the hot cylinder system - the second liquid cooling circuit, depending on the heat transfer coefficient of the heat pump.

Keywords: processor, heat flow, thermal resistance, Laplace equation, heat pump, heat exchange, Stirling backflow, cooling system

Numerical solution to the problem of heat transfer in boundary layers transparent Strip on the walls, exposed on the opposite side of the radiant-convective heating. Study of influence of mode parameters on heat transfer process of tasks carried out in the case of the gradient flow and included the most typical variants of transportation processes. The purpose of the real work is studying of processes of transfer at non-linear boundary conditions, obtaining approximate and analytical decisions non-linear warm and a mass transfer, establishment of communication between regime parameters and physical interpretation of results of a research. Also some conjugate problems of heat exchange in the presence of radiation are studied. The analysis received decisions is carried out. The executed research allowed to establish that existence of a transversal overflow of heat in a wall and also the radiation of a surface have significant effect on the nature of distribution of the surface temperatures.

Keywords: boundary layer, convection, radiation, gradient flow, conjugate heat transfer

The paper presents a developed mathematical model for analyzing the dynamics of thermal losses. The influence of the massiveness of the enclosing structures on the propagation of the heat flux is substantiated. The developed model makes it possible to estimate how the heat load of the heating system of the room under consideration changes over time. Analysis of the dynamics of the change in the heat load can help in choosing a method for regulating the heat transfer of heating devices

Keywords: Dynamics of heat losses, constructions of different massiveness, control range, thermal load, amplitude of oscillation