This study clarifies the heat transfer characteristics of flow boiling in a narrow vertical rectangular channel at each stage and optimizes the performance of a heat exchanger. The flow pattern and local heat transfer characteristics in a narrow vertical rectangular channel of steam heating with dimensions of 1400 x 250 x 2.75 mm (l x w x s) were experimentally investigated using deionized water as the working medium. Based on the visualization data, the mechanical model and empirical formulas in previous literature, a preliminary derivation of the flow pattern transition criterion for steam heating in a vertical rectangular narrow channel was obtained. The effects of the inlet temperature, mass flux, and heating power on the local heat transfer characteristics were analyzed in conjunction with the flow patterns. Based on the parametric analysis of the experimental data, a new flow boiling heat transfer correlation formula was obtained and applied to the experimental conditions. The results showed that an increase in the inlet temperature had a positive effect on the nucleate boiling section, whereas the effect on the local heat transfer coefficient was minimal after entering the churn flow phases. The increase in mass flux decreased the local heat transfer coefficient in the nuclear state boiling stage and enhanced the local heat transfer coefficient in the evaporation zone of the liquid film flow. The peak of the local heat transfer coefficient tended to shift to the left as the heating power increased. The proposed heat transfer correlation equation could well predict the local heat transfer coefficient of flow boiling in a vertical rectangular narrow channel heated by steam under these experimental conditions.
With its large scale and high flexibility, liquefied air energy storage is very suitable for integrated operation with existing power generation systems to improve the regulation ability of the grid. A novel liquified air energy storage system coupled with coal-fired power unit for heat exchange through the water/steam and the compression/expansion air is proposed. The thermodynamic model of a novel liquified air energy storage system is established with a 307 MW coal-fired power unit as the coupling object. And the parameters design and performance analysis of the coupling system are carried out. The results show that the efficiency of the system can reach 51.64 %. At this time, the corresponding energy storage/release pressure is 18/7.2 MPa. The highest return on investment of the system can reach 19.59 %, and the shortest dynamic payback period can reach 4.73 years. The sensitivity analysis shows that decreasing the heat transfer end difference of the regenerator and increasing the adiabatic efficiency of the compressor are conducive to reducing the exergosy destruction of equipment and improving the efficiency of the system. It is beneficial to improve the economic performance of the system to increase the difference between peak and valley electricity prices and the amount of peak regulation subsidy.
THE PURPOSE. Determination of effective methods of carbon dioxide capture and utilization, search for promising solutions and testing of carbon dioxide capture methods at a laboratory facility. The most popular absorption methods of CO2 capture, in which the gas reacts with a liquid absorbent.METHODS. The laboratory setup includes the CO2 source itself (gas cylinder), an absorber, and a flask with sodium hydroxide solution to analyze absorption efficiency. Efficiency is evaluated by the titrimetric method, where a solution of hydrochloric acid is used as a titrant, phenolphthalein and methyl orange act as indicators.RESULTS. For the analysis, available absorbents were selected, which are available at most thermal power plants. As a result of a laboratory experiment, it was found that a quicklime suspension of 6% has the highest sorption capacity.CONCLUSION. The decarbonization of the industrial energy sector is a complex process that requires global changes in fuel policy, namely the transition to carbon-free energy resources. An alternative energy resource is hydrogen energy, but even here carbon dioxide emissions are present. Capture and disposal will help decarbonize the main sources of pollution. Industrial carbon dioxide capture has great potential, which lies in the variety of uses of sorption materials.
PURPOSE. Development of technological solutions to reduce the amount of wastewater and reuse them in the cycle of the modernized water treatment plant at the Sterlitamak thermal power plant.METHODS. To achieve this goal, the methods of system analysis of the chemicaltechnological system were used, the sources and transformation of pollutants were determined.RESULTS. To date, Russia has experience in the disposal of wastewater from water treatment plants of energy enterprises. Basically, this method is based on neutralization with the use of various additional chemical reagents. As a result of the analysis, variants of technological schemes of a modernized water treatment plant were presented, where the concentrate after the reverse osmosis installation undergoes additional purification with the use of H- and Nacationite filters with joint or local use. The variant of the technological scheme will directly depend on the qualitative and quantitative composition of wastewater. A gypsum reactor is provided for the disposal of acidic waste regeneration solution, where gypsum is obtained as a product. These technological schemes make it possible to purify the wastewater of the installation and reuse it. These schemes are low-cost and are promising directions for the development of stations. conclusion. The developed technological solutions do not require the purchase of expensive chemicals and equipment, but only require the re-binding of equipment and the presence of a contact tank. These technologies are resource-saving, as a result, the consumption of raw water is reduced due to the reuse of waste, i.e. the cycle is low-flow. In recent decades, many industries have switched to a low-waste policy, since wastewater carries a large amount of valuable substances that can be recycled and reused.
THE PURPOSE. The work is devoted to the study and analysis of the accident on August 22, 2016 at the Reftinskaya GRES, which resulted in the operation of technological protection and, as a result, cascade shutdowns with a violation of the integrity of the UES of Russia. It should be noted that Reftinskaya GRES is one of the largest thermal power plants in Russia, with an installed capacity of 3800 MW. METHODS. Within the framework of the task set, the authors carried out a number of studies aimed at identifying cause-and-effect relationships on the basis of accident investigation acts. RESULTS. The grounds for the occurrence and development of the accident are investigated and the main causes of the accident are identified. CONCLUSION. A unified cause-and-effect diagram of the occurrence and development of an accident was compiled, indicating the events, the time of their occurrence and the links between them.
THE PURPOSE. Conduct a study to improve the reliability of forecasting the magnitude of power consumption and power losses at an industrial enterprise.METHODS. Methods are used to determine and predict the parameters of consumption and losses of electricity at industrial facilities.RESULTS. To clarify the magnitude of electricity losses, it is proposed to use coefficients that take into account the type of load curves and show the ratio of the values of the sum of the squares of currents (powers) of the variable load curve and the values of the sum of average currents (powers), that is. the ratio of power losses during load operation according to variable and uniform schedules (Kgraph), as well as a coefficient that takes into account the topology of the circuit (Ktop). The study of radial and main circuits of networks was carried out and the losses of electricity were determined using the proposed coefficients. The values of equivalent resistances of shop circuits of networks of various topologies are calculated. The operational data of the section of the workshop network are given. It was revealed that with a constant technological process, an increase in the equivalent resistance of the network circuit is due to an increase in the resistance of the contacts of switching devices installed on the lines. The value of the estimated supply of electricity was determined using the parameter of the average value of the equivalent resistance. At the same time, the error in calculating the estimated supply in relation to the actual annual supply of electricity amounted to 2,63%. According to the retrospective values of the average equivalent resistance of the circuit, it is possible to determine the predicted value of this parameter using the average value of the coefficient of change in the equivalent resistance. These characteristics of the scheme are recommended to be used in the assessment and forecasting of losses and the estimated supply of electricity, which will increase the reliability of the predicted parameters for industrial facilities.
THE PURPOSE. To estimate the most effective length of the working blade of the last stage of a powerful wet-steam turbine in terms of obtaining its maximum efficiency and to optimize the parameters of this stage in the design mode. For this stage, perform multi-mode optimization to select the main characteristics of the stage operating with maximum efficiency according to a given model daily load schedule. METHODS. When solving this problem, the method of calculating the axisymmetric flow of steam in the flow part of the turbine stage as an inviscid single-phase working fluid relative to a stationary guide device and rotating with an angular velocity ω of the impeller used, and the losses energy calculated according to the axisymmetric method of the MPEI. RESULTS. The article describes the relevance of the topic, discusses the features of the use of the author's software in solving the tasks. The characteristics of the stages with different lengths of the working blades presented and the results of their calculation in the nominal mode are given. A model daily schedule selected for a nuclear power plant turbine operating in the central region of Russia. The results of calculations of variable modes of the last stage of the turbine operating according to this daily schedule presented. CONCLUSION. The choice of the maximum length of the working blade is limited not only by its strength characteristics, but also by the increase in wave losses in the gratings due to an increase in the optimal available heat drop, or rather the associated increase in supersonic speeds near the meridional contours. So for a high-speed turbine To-1200-6,8/50 the maximum efficiency of the last stage is achieved at a length of 1400 mm, both when the turbine is configured with both three two-flow LPC and four. Selection of the main characteristics of these stages, such as the available heat drop, the degree of reactivity, etc. it should be made taking into account the variable operating modes of the turbine on the basis of the forecast of daily schedules of loads of turbine units. When using a typical daily load schedule, the average internal relative efficiency in the range of operating modes according to this schedule is higher by 0.6 % when choosing a 10% increased available heat drop compared to the optimal one in the design mode.
OBJECT. Experimental studies on optimization of the output electrical and mass transfer characteristics of the reverse electrodialysis process. METHODS . System analysis techniques were used in this work and a mathematical model was developed to describe the movement of water streams and the concentrations of substances in them. The equipment involved, designed for experimental and industrial testing of the proposed technologies with technical characteristics of the developed apparatuses and installations, is described. RESULTS . RED (reverse electrodialysis) is a new membrane technology for renewable energy production using salinity gradients. The ultimate goal of RED is to achieve the highest possible value of power density, which depends on several parameters related to the intrinsic electrochemical characteristics of the membranes, stack configuration (number of cell pairs, channel length), hydrodynamics, nature of the working solutions (ionic composition, concentration), and others. The paper presents experimental studies on the influence and modeling of various parameters of the reverse electrodialysis operation on the output electrical characteristics of the system. CONCLUSIONS . It is shown that the system output power is significantly influenced by the composition of solutions in the near-electrode chambers, external load and internal resistance, concentrations of working solutions and time of the experiment. The maximum electrical efficiency was 56% (power density 0.34 W/m2) in semi-industrial electrodialysis reverse electrodialysis experiments using model NaCl solutions, K 3 Fe(CN) 6 /K 4 Fe(CN) 6 and Chinese 0.6 mm thick IONSEP membranes.
THE PURPOSE. Wastewater treatment and waste disposal of sorbents obtained from residual biomass. Obtaining biocoke from sludge. Ensuring maximum calorific value of raw materials.METHODS. X-ray phase analysis of ash after burning spent sorbents. Thermogravimetric analysis of biocoke in an oxidizing environment. Elemental analysis evaluation of raw materials and products of municipal solid waste thermal conversion. Experimental analysis of municipal solid waste morphological composition for the municipal district.RESULTS. Completed experimental studies on the analysis of sewage sludge and an assessment on energy and environmental indicators. The substation of partial replacement of fossil fuels by using municipal solid waste in thermal energy generation. Scheme of wastewatertreatment and application of used sorbents as fuel. In order to clarify the calorific value, experiments were made in a calorimetric bomb which showed that biocoke has a lower calorific value of 11.5 MJ/kg. The calorific value of biocoke was obtained according to the data of a thermal analyzer, which is 8–12 MJ/kg and depends both on the type of initial sewage sludge and on the mode of biocoke preparation.CONCLUSION. The obtained results make possible to evaluate the effectiveness of biocoke usage obtained by conversion of sewage sludge for the disinfection of MSW landfills and the impact on restoring soil quality.
RELEVANCE. Among the various methods for assessing the technical condition of power equipment, vibration diagnostics occupies an important place. Therefore, improving the quality of hardware for vibration diagnostics is currently extremely important. THE PURPOSE. To develop a vibration sensor with a new principle of operation for systems of technical vibration diagnostics of power equipment, as well as to theoretically substantiate the performance of the proposed sensor. METHODS. When solving the set goal, the main provisions of the theory of vibration diagnostics were applied. RESULTS. A design of the vibration acceleration sensor has been developed, the peculiarity of which is that it is excited by means of constructive coupling capacitors, the first electrode of which is made in the form of a thin-walled metal split cylinder, the role of the second electrodes is performed by the lower row of the winding of each measuring coil, and the function of the inertial element is performed by a screen made in the form of a metal ring fixed on a suspension in the form of a membrane. Based on the electrical equivalent circuit of the sensor, a theoretical substantiation of its operability and efficiency was made. Variants of circuit solutions for the primary and secondary measuring transducers of the measuring device for vibration diagnostics systems have been developed. The primary measuring transducer contains directly a vibration displacement sensor, a sinusoidal voltage source, an input differential measuring amplifier and an analog filter containing a narrow-band filter, a broadband amplifier and a buffer amplifier. The secondary measuring transducer contains a quadrature detector of information signals, an output buffer amplifier and a quadrature reference voltage driver. A block diagram of the hardware solution for the vibration acceleration registration system is also proposed. CONCLUSION. The developed sensor has improved output characteristics and can be used not only for vibration control of power equipment, but also for measuring mechanical vibrations in technical diagnostic systems of various other machines and mechanisms, as well as for tasks of spectral seismic exploration.
RELEVANCE. The reliability of power supply to consumers depends on the reliability of all elements of the power supply system, including relay protection and automation devices (RZiA). Knowing the current values of the reliability indicators of various devices makes it possible to take them into account when designing RPA, choosing more reliable devices, identifying shortcomings in RPA and performing work to eliminate them. THE PURPOSE. Due to the lack of open data on the current values of reliability indicators of relay protection and automation devices (RPA) of electric networks of 10-110 kV, the question of their determination on the example of power systems of various regions is relevant. METHODS. The authors present and analyze official statistical data on the number of emergency failures, false and correct actuations of relay protection and automation devices in the electric grid organization - branch of PJSC «Rosseti Center» – «Ore lenergo» for 2013-2021. RESULTS. In the course of the study, numerical values of the following reliability indicators of relay protection and automation devices were determined: the failure rate and the frequency of excessive triggering. Relayprotection and automation devices, for which reliability indicators have been determined, are used to implement arc protection, maximum current protection, automatic re-activation, differential protection of buses and transformer, transverse directional differential protection, gas protection of transformer, differential-phase protection. CONCLUSION. The values of the failure flow for different types of relays and microprocessor devices of the RPA are established, for example, for an electromechanical relay of the DZT-11 type used to implement differential protection of transformers with a higher voltage of 110 kV, the failure flow is 0,2 year -1 /100 pcs., and the frequency of excessive triggering is 22,22 year -1 /100 pcs. Conclusions are drawn about the need for measures to regulate the settings and maintenance of devices of various types.
PURPOSE. To consider the experience of using chemical water treatment waste in economic activity. To analyze scientific publications of Russian and foreign authors in order to determine the most popular industries in this waste and information about projects already implemented in Russia and abroad. To provide a brief analysis of the main areas of processing and disposal of sewage sludge in the world and in Russia. To assess the prospects for the use of chemical water treatment waste in the treatment of sewage sludge.METHODS. To achieve this goal, an assessment of the environmental impact of chemical water treatment waste on the environmental situation and human health was carried out on the example of Kazan CHP-1 (KTEC-1). A number of studies of KTEC-1 carbonate sludge have been carried out to determine the granulometric and elemental composition. results. The physico-chemical composition of carbonate sludge depends on a number of parameters of the water treatment system at an energy facility: the process of liming and coagulation of water, the amount of insoluble salts, the dewatering technology used, etc. Carbonate sludge is insoluble in water, has a typical chemical composition containing calcium carbonate (CaCO3), calcium oxide (CaO), magnesium carbonate (MgCO3), magnesium oxide (MgO), iron hydroxide (Fe(OH)3), silicon dioxide (SiO2), etc.CONCLUSION. The use of this type of technological process makes it possible to reduce the amount of calcium oxide used and replace it with calcium oxide from carbonate sludge. The use of carbonate sludge as a sediment stabilizer due to the CaO content is confirmed by laboratory studies. Due to these data, the disposal of chemical water treatment waste is ensured, less pollution of environmental objects is achieved.
THE PURPOSE. Consider the indicators of the operation mode of the Kuibyshev reservoir over the past 15 years, affecting the state of the fish stock; identify the main trends in changes in water volumes in the reservoir due to climate change, the features of the level regime for the ecological solution of the problem of preserving aquatic biological resources. METHODS . A comparative analysis of our own research and literature data on the hydrological characteristics of the Kuibyshev reservoir, the temperature regime of the region and the state of the ichthyofauna was carried out. In this work, to analyze the current state of the hydrological regime, data provided by the Verkhniy Byef gauging station of the branch of JSC RusHydro - Zhigulevskaya HPP and the State Committee of the Republic of Tatarstan for Biological Resources were used. RESULTS. It is shown that the average water level in the Kuibyshev reservoir for the last period ranged from 50.34 to 52.31 m at NHL - 53.00 m BS, DVL - 45.5 m. Based on the totality of characteristics in terms of average water levels and inflows, 2010, 2011, 2021 can be attributed to low-water years, 2007-2009, 2012-2020 to years with average water content, and there were no high-water years during this period. The analysis of the dynamics of changes in the maximum and minimum water levels was carried out and changes were identified: the minimum recorded water level (48.16 m) was noted in January (2011), at the end of the 20th century, the minimum levels were recorded in March - April and they were lower by 1-1, 5 m in summer drawdown and 2.5 - 3.5 m in winter, the level rise occurs in April, while earlier it was in May. The duration of the high-water period (about 53 m) increased to 4 months. The minimum volume in the reservoir was recorded in the winter period of 2010-2011 - 36.14 km3, the maximum volume is 57.66 km3 in the winter period of 2019-2020. Maximum water discharges are carried out mainly in the second half of April and early May. Minimum discharges are carried out in different periods. It is shown that the number of days with an air temperature above 15°C, which characterizes the fishery zone, varies in different years of the last period from 71 days (2017) to 133 days (2020). CONCLUSION. A relative increase in temperature was noted as the most important environmental factor for the development of aquatic bioresources; currently, the process of accelerating eutrophication of shallow areas of the Kuibyshev reservoir is observed. The regular death of fish in different parts of the reservoir, combined with factors such as low water levels and high temperatures, creates the preconditions for “local catastrophes” at the level of ichthyocenoses, the area of “local catastrophes” is expanding due to climate change. The mortality of fish is a mechanism for the release of the ecosystem from excess organic matter, and the mortality of a small particle indirectly indicates a high abundance of low-value and weedy fish, the number of which must be reduced.
THE PURPOSE. The features of the rheological behavior of composite fuel oil suspensions depending on the shear rate, temperature and composition of the composite fuel are considered. METHODS. Suspensions with a coal content of 30, 40 and 50% (by weight) were prepared. The mixing time varied from 1 to 10 minutes. The samples of fuel oil were examined using a Rheomat RM 100 rotary viscometer to determine the values of dynamic viscosity at different shear rates and temperature. RESULTS. The results of experimental studies of the dynamic viscosity of fuel oil as a function of the shear rate and temperature are obtained. The best values of coal dust content in fuel oil suspensions for fuel transportation have been determined. CONCLUSION. The obtained research results can be used by both energy companies and transport companies to determine the technological viscosity indicators of composite suspension fuels used as boiler fuel and fuel for marine engines.
RELEVANCE . A review of the current state of research on coal-water slurries in Russia and abroad is presented. Coal-water slurries are promising alternative types of energy fuels. Their use in the energy sector will allow generating thermal and electrical energy. It is possible to use a fairly wide range of substances as components of such fuels. One of the preferred types are various waste. The analysis of modern literature has shown a fairly wide range of directions for the study of multicomponent coal-water slurries. THE PURPOSE . To provide information on the current state of research in the field of technologies for the preparation, spraying and combustion of coal-water fuels, as well as on existing and promising additives to such slurries. METHODS . The study was carried out by the method of collecting and structuring information. RESULTS. The review of the current state of research in the field of technologies for the preparation, spraying and combustion of coal-water fuels, as well as existing and promising additives to such slurries, was carried out. It was found that additives of liquid combustible waste and biomass contribute to reducing the ignition delay time. At the same time, such additives do not reduce the quality characteristics of spraying multicomponent coal-water slurries. A number of components reduces the amount of emissions of combustion products of such fuels into the atmosphere. The influence of additives and components of coal-water slurries on their characteristics and properties was analyzed. It was shown that liquid components contribute to the intensification of ignition and combustion processes. In addition, their introduction into the fuel composition has a positive effect on the rheological properties of slurries, the characteristics of their spraying, combustion and the concentration of harmful emissions. CONCLUSION . Coal-water slurries are promising alternative types of energy fuels. The introduction of combustible components into the composition of coal-water slurries can significantly improve the rheological properties, which can improve the storage and transportation characteristics of such fuels. The established positive characteristics and properties of coal-water slurries provide prerequisites for the full-scale introduction of such fuels into industrial power engineering.
RELEVANCE. The task of prompt and accurate determination of the fault location in cable transmission lines is one of the key in the process of ensuring a reliable and uninterrupted supply of electricity to consumers. The development of a new algorithm for solving this problem, which will minimize the time and resources spent on finding damage, is an urgent area of modern research. THE PURPOSE. Consider the main shortcomings and limitations of the existing methods of determining fault location to cable lines. Develop an algorithm for the determining fault location to cable line based on the theory of long lines using the original amplitude-phase coordinate characteristics. Implement an algorithm for obtaining theoretical characteristics of the dependence of the input current parameters on the line fault coordinate using a specific numerical example. METHODS. When solving the tasks set, the methods of the theory of long lines and the classical theory of electrical circuits were used, implemented by means of the Wolfram Mathematica software package. RESULTS. The article describes the relevance of the topic, considers the main shortcomings of the existing methods of determining fault location to cable lines. An algorithm for determining the fault location for a single-phase cable line has been developed and implemented on a specific numerical example, based on the joint use of a special type of duplicated coordinate-dependent (ACC) and (FCC) characteristics calculated using the Wolfram Mathematica software package. The corresponding graphic constructions are given and a variant of the practical implementation of the proposed algorithm is described. CONCLUSION. According to the results of theoretical calculations, the proposed algorithm for determining the location of damage to a single-phase cable power transmission line allows, with a given accuracy, to determine the coordinate of damage for cases of breakage and short circuit in the entire range of line length. The obtained theoretical calculations need appropriate experimental testing in the next stage of research.
RELEVANCE. Due to the difficulties of finding eigenvalues and proper functions for bodies with axial (cylinder) and central (ball) symmetries defined in classical methods from the edge Sturm-Liouville problems, including Bessel equations whose exact analytical solutions are not obtained (known only numerical solutions, described by approximation formulas), there is a need to develop analytical methods of their solution. THE PURPOSE . Using orthogonal methods of weighted residuals, an approximate analytical method for determining eigenfunctions and eigenvalues in boundary value problems with axial and central symmetry (cylinder, ball) has been developed. METHODS . The method is based on the use of orthogonal systems of coordinate functions and additional boundary conditions. Latter are in such a form that their fulfillment by the desired solution is equivalent to the fulfillment of the differential equation of the boundary value problem at the boundary points of the region, leading to its fulfillment inside the considered region. Moreover, the accuracy of the equation depends on the number of approximations, which, in turn, depends on the number of additional boundary conditions used. Using the orthogonality property of trigonometric coordinate functions included in a series representing eigenfunctions makes it possible to increase the accuracy of the fulfillment of the differential equation of the Sturm-Liouville boundary value problem and the accuracy of determining the eigenvalues. To satisfy the initial condition, its residual is compiled and the condition of its orthogonality to all coordinate functions is required. The orthogonality of trigonometric systems of coordinate functions with respect to the unknown constants of integration leads to a system of algebraic linear equations, the number of which is equal to the number of approximations. As a result, the fulfillment of the initial condition is simplified and the accuracy of its fulfillment is increased. RESULTS . The advantage of the method is that the resulting solution contains only simple algebraic expressions, excluding special functions (Bessel function, Legendre function, gamma function). CONCLUSION . Thus, bypassing direct integration over a spatial variable, the use of additional boundary conditions makes it possible to find a solution of any complexity of the equations of the Sturm-Liouville boundary value problem, which reduces to the definition of simple integrals.
THE PURPOSE. One of the directions of energy saving and energy efficiency improvement is the reduction of consumption of fuel and energy resources. A large amount of thermal energy is spent on heating buildings and structures during the heating season. To reduce heat losses through the building envelope, various heat-insulating materials with low thermal conductivity are used. The purpose of this research was to study the problem of developing the technology of lightweight concrete based on diatomite rocks, as well as uneven inclusions of filler from microspherical granules arising during its creation, assessing the effect of the presence of zones not occupied by microgranules on the insulating properties of the composite material, as well as determining the effect of the volume content of microspherical granules on the value of thermal conductivity.METHODS. In this work, we studied the production of lightweight structural concrete with porous aggregate synthesized from diatomite rocks of the Vladimir region, as well as the effect of the presence of zones not occupied by microgranules on the insulating properties of the composite material. RESULTS. The results showed that the distribution of microgranules in the matrix has a significant effect on the insulating properties of the composite, and the presence of voids in the material contributes to heat losses and a decrease in the thermal resistance of the material.CONCLUSION. The technology for obtaining the developed concrete does not differ from the technology for the production of high-class concrete, which allows the use of widely used concrete equipment.
RELEVANCE. Vertical cone diffusers are used in various technical applications: heat exchangers, gas cleaning units, boilers, industrial furnaces, dryers, ventilation devices, nozzle systems and others. For their efficient operation, it is necessary to ensure a uniform supply of the working medium to the device, which is determined by the characteristics of the flow in thediffuser. Thus, the study of the aerodynamics of technological devices with conical diffusers is an urgent task for gas-dynamic improvement and the search for ways to control flow characteristics. THE PURPOSE. To establish the evolution of the velocity field along the height of the cylindrical part of the diffuser for different configurations of the supply tubes, and also to determine the magnitude of the change in the intensity of turbulence along the height of the diffuser under different initial conditions based on experimental data on the instantaneous values of the air flow velocity. METHODS. Measurement of instantaneous values of air flow velocity is carried out using a constant temperature hot-wire anemometer. The article provides data on velocity fields and turbulence intensity along the height and along the diameter of the cylindrical part of the diffuser when air is supplied through tubes of different configurations. Feed tubes with cross sections in the form of a circle, a square and an equilateral triangle were used. RESULTS. The article provides a detailed description of the experimental stand (including key geometric dimensions), instrumentation and measurement system, and data processing techniques. The ranges of changes in the initial conditions for the experiments are presented. A comparison of the aeromechanical characteristics of flows in a vertical diffuser when air issupplied through different tube configurations is carried out. CONCLUSION. It is shown that in the diffuser there is a drop in the average velocity upstream, which is typical for all configurations of the supply tubes. It has been established that profiled tubes influence the shape of the velocity field. It was found that the values of turbulence intensity vary from 0.05 to 0.39 (the highest values were typical when air was supplied through profiled tubes). It is shown that the intensity of turbulence has its maximum values at a height of 300-350 mm, which is typical for all investigated tube configurations.
