The numerical investigation of aerodynamic and power engineering characteristics of the exhaust compartment of high power steam turbine in the range of modes has been carried out. The wet steam with tabular parameters was used as an actuating medium. The compartment includes the last stage of the LPC with the preliminary provided interstage gap, working medium sampling system, wire damper communication and tip-clearance leakage, the exhaust manifold with the power system, the reducing sleeve with the pipe package and the chamber for the removal of moisture from the rim gap. The stream structure and the compartment characteristics in nominal and partial modes, the effect of injection and tip-clearance leakage depending on the mode are discussed. A low efficiency of the steam injection to provide the without-separation-streamline of the convex envelope of the diffuser under conditions of off-axis steam output from the last stage has been shown.

Keywords:
the last stage of LPC, axiradial diffuser, exhaust manifold, moisture removal system, wet steam, numerical modeling, and partial modes

Shvetsov V. L., Kozheshkurt I. I., Коnev V. А., Solodov V. G., Khandrimailov А. А. Studying Aerodynamic and Power Engineering Characteristics of the Exhaust Compartment in the Low Pressure Cylinder in the Range of Different Modes. NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 5-13.

This scientific paper is devoted to the issues of numerical simulation of working processes in the combustion chambers of synthetic gas–driven gas turbine engines. An ideal organization of the burning process in the combustion chamber is the main factor determining the ecological characteristics of the gas-turbine unit that together with technical and economic indices of the plant define its competitiveness. The three-dimensional investigation carried out to determine the influence of the synthetic gas composition on the working process in the combustion chamber of a diffusion type of the gas turbine engine of 2.5 MW showed that the replacement of the natural gas (methane) by the synthetic gas for the pilot combustion chamber of the gas turbine engine making no essential engineering changes of the flame tube results in an increased exhaust of toxic components, in particular nitrogen oxides NO in the range of 66 to 200 ppm depending on the fuel gas composition. It has been shown that an improvement in the performances of gas turbine engines and an increase in the stability of combustion processes of low-cal synthetic gases are possible due to the use of the double-zone technology proposed for the burning of hydrocarbon RQL fuels (Rich-Burn, Quick-Mix, Lean-Burn). It has been established that in order to decrease the emission of nitrogen oxides to 70 % for GTE when the combustion chamber is operated using the RQL technology in comparison with the traditional diffusion circuit it is necessary to create conditions for the efficient mixing of the reagents in the primary zone of the chamber preventing the formation of the mixture of a stochiometric composition in it, which is achieved through the choice of the rational relationships of the geometric sizes of the fuel burning plant, and the ratio of the diameter of the output section of the zone rich in fuel-&-air mixture to the diameter of the hot tube must be in the range of 0.40 to 0.55.

Keywords:
combustion chamber, synthetic gas, RQL-technology, mathematic simulation and the burning.

Serbin S.I., Goncharova N.A., Vilkul V.V. Studying the Peculiarities of the Working Process in the Combustion Chamber of Synthetic Gas-Operated Turbine Engine of 2.5MW . NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 14-18.

One of the promising conceptions for the design of nuclear power stations of the fourth generation is considered to be the conception of a high-temperature gas-cooled reactor that uses helium as an actuating medium. The conversion of the energy of the heated helium into mechanical energy with the subsequent conversion of it into the electric power is performed in the energy conversion block that represents the gas turbine plant consisting of the turbocompressor of a vertical type on electromagnetic bearings with the two-cascade axial compressor, a helium gas turbine and highly efficient heat exchange equipment. This paper describes the computational investigation of the parameters of the thermodynamic cycle of the energy conversion block for the modular nuclear power plant with the high temperature helium reactor having the heat power of 250 MW in the electric power generation mode and in the combined mode of the joint electric power and heat production for the needs of heat supply utilities. The influence of the efficiency factor of some elements of the compressor of high and low pressure and that of the helium turbine and the heat regeneration factor on the efficiency of the cycle of nuclear power plant has been studied.

Keywords:
modular nuclear power station, gas cooled helium reactor, gas turbine plant, complex thermodynamical cycle, and the cycle efficiency

Halatov A.A., Severin S.D., Donyk T.V. Influence of the Efficiency Factor of Energy Conversion Block Elements on the Cycle Efficiency of the Modular Nuclear Power Plant (NPP) Equipped with the Gas Cooled Helium Reactor . NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 19-25.

The main specific features of the determination of the thermally stressed state and the assessment of the resource wear out of the high temperature rotors of HP and LP steam turbine T-250/300-240 have been described. To define the actual modes of operation, boundary conditions of the thermal exchange in the stages and seals of the rotors we used the data of computer-aided process parameter control system (CAPPCS) that were determined during the turbine operation. Nonstationary temperature fields and thermally stressed state in high temperature rotors were obtained using the method of finite elements (MFE). To assess the resource wear out we determine the damageability resulted from the low-cycle fatigue and the creepage in the most dangerous rotor zones.

Keywords:
thermally stressed state, rotor, turbine, technological parameters, and the damageability.

Shulzhenko N.G., Gontarovskiy P.P., Garmash N.G., Efremov Yu.G. Diagnosing the Thermally Stressed State and Estimating the Resource Wear out for the Rotors of High and Low Pressure Turbine T-250/300-240 . NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 32-37.

The conditions under which the vibrostressed state of the turbine blades of gas turbine engine (GTE) is investigated using the resistance strain gauge have been given. The consideration was given to resistance strain gauge with the film sensitive platinum and metal ceramic-based elements and the substrate-type isolator made of high temperature cement of a phosphate hardening and the methods of the investigation of the vibrodeformations of GTE elements including their application. The vibration strength test data of high temperature film-type resistance strain gauge and the scheme of the process flow diagram of their attaching (application) to the turbine blade have been given.

Keywords:
resistance strain gauge, sensitive elements, substrate-type isolator, binder, gas-turbine engine, turbocompressor, working blade, vibrostrength, and the resonance.

Gusev Yu.A., Kahrai Kambiz, Prochan G.A., Yakovlev Yu.A. Studying the Vibrostressed State of the Elements of Gas Turbine Engine Using a High Temperature Film-Type Resistance Strain Gauge . NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 38-43.

This paper presents the numerical models for the analysis of combustor fuel spray, characteristics, invarious injection conditions in a can type of combustor with a double stage radial swirler. Spray consists of twofundamental and consecutive steps, means the primary breakup and the secondary breakup. The primary breakupis modeled by Linearized Instability Sheet Atomization (LISA) which are mostly used in a pressure swirlatomizers. Secondary breakup is modeled by Taylor analogy breakup model (TAB). The trajectory and velocityof generated fuel droplets is determined by Lagrangian Particle Tracking. Characteristics of jet breakup, dependson a variety of factors such as turbulence, injection pressure drop, velocity profiles, nozzle geometry, and thephysical state of the liquid fuel. In this paper Jet-A aviation fuel (kerosene), modeled as a two-componentsurrogate fuel (by mass 60 % C10H22 and 40 % C9H12). The standard k–ε model with the enhanced walltreatment and the Euler-Lagrange method were employed for the simulation of the turbulence and spray. Allresults of the simulation in this paper are analyzing in 3 various injection conditions and one of these cases waschosen and implemented in a real annular combustion chamber of a gas turbine. A PDF Flamelet model wasemployed to simulate combustion process.

Keywords:
primary breakup, pressure swirl atomizer, spray combustion

Masoud Hajivand CFD Modeling of Kerosene Combustion with Various Initial Conditions and Fuel Droplet Diameters . NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 54-66.

The paper describes two methods of design of blading systems of radial-axial turbines for an Organic Rankine Cycle (ORC) cogeneration unit working with silica oil MDM. Preliminary design of the turbine flow part draws on methods of 1D calculation and pre-selection of basic geometric characteristics. Final design involves also methods for construction of 3D geometry and methods of 3D flow calculations of the turbine flow part. 3D numerical calculations of turbine flows are made with the help of the software package IPMFlow, developed based on the earlier codes FlowER and FlowER-U, or using the software complex ANSYS. 100 kW ORC turbine designs with the single-stage radial-axial turbine are elaborated in this paper.

Keywords:
cogeneration unit, Organic Ranking Cycle, CFD, radial-axial turbine

Klonowicz P., Rusanov R., Rusanov A., Lampart P., Suchocki T.K., Surwilo J. Methods for design of radial-axial turbines for ORC cogeneration unit working with MDM. NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 67-77.

Consideration was given to the drawbacks of power stations that work using the temperature difference of the ocean water. The power plant with the hydrosteam turbine that eliminates these drawbacks has been proposed. Thermodynamic cycles with the hydrosteam and steam turbines were analyzed. It has been shown that the proposed power plant is 2.4 times more efficient in comparison with the known Claude-Buchero plant. There is nothing strange, because the greatest portion of heat supplied together with the surface water to the evaporator of the known plant is discharged unused back to the ocean. To reduce hot and cold water flow pipeline resistance it was suggested to add to the flows the polymers that are obtained on the basis of gases released under vacuum from the sea water. The expediency of the use of hydrosteam turbines using the low potential heat of condensation electric power stations has been shown. The calculations showed that the equatorial zone of the ocean with the area of 5 mln.km2 can produce more than 7 TW of the energy. It is reasonable to arrange on oceanic stations the energy-intensive production of alloys, protein and chemical products.

Keywords:
power plant, hydrosteam turbine, efficiency factor, and soluble polymers.

Troshenkin B.A., Troshenkin V.B. Prospects of the Use of Hydraulic Gas Turbines to Make Use of the Low Potential Heat of Industrial and Natural Waters. NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 82-88.

The numerical methods of the determination of dynamic and static characteristics of the plate-type heat exchangers with the back-stream circuit of the motion of heat carriers have been considered. The numerical method was developed on the basis of implicit difference scheme. The data of multivariant computations of transient processes of the heat exchanger module are given taking into consideration the longitudinal heat conduction of the separation wall made of aluminum and steel. The stationary state of the heat exchanger and its performances are considered as the completion of the transient process. In the range of adopted values of the velocity and temperature of the flows and partition wall thickness the longitudinal heat conduction affects the parameters of the transient modes of heat exchanger operation; for the stationary states this influence is insignificant.

Keywords:
heat exchanger, heat carrier, dynamics, heat conduction, temperature, heat consumption, acceleration curve, algorithms, time constant, and the difference scheme

Shevelev A.A., Pavlova V.G., Abdullin S.Yu. Influence of Longitudinal Heat Conduction on the Dynamic and Statistical Characteristics of the Plate-Type Heat Exchangers. NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 89-96.

This scientific paper describes basic thermoeconomic models used to define the cost of the heat generated by the vapor compression heat pump system. A universal method of the estimation of the quality of the flows of energy was used for the testing of thermoeconomic models. It is based on the equations of cost and exergic balances. Statistical characteristics of the heat pump system of a \”water-air\” type were computed. A comparative analysis was carried out with regard to the exergic efficiency of the elements of the heat pump system and the cost of the exergy destruction in each unit element. The conclusion was made that the models are functional and can be used to estimate the cost of the heat generated by the heat pump system. However, to perform the in-depth thermoeconomic analysis for the heat pump system it will be reasonable to use the model based on the negentropy approach. It allows for the correct estimation of the exergy destruction cost.

Keywords:
negentropy, exergy, thermoeconomic model, and the heat pump system.

Tarasova V.A. Comparative Analysis of the Thermoeconomic Models of the Vapor Compression Heat Pump System. NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 97-107.

This paper describes the methodological approach to the determination of boundary conditions on the surfaces of the diaphragm rim and internal cylinder casing of the steam turbine. The thermal flow running from the flow pass section to the intercasing space through the diaphragm rim and the internal casing is divided into three regions according to specified boundary conditions on the surfaces of narrow slots between the diaphragm rim and the casing boring, on the contact diaphragm bearing surface and on the surface of the clearance formed by the flange of the tip-clearance leakage seal. The regions were selected taking into consideration the thermal resistance of boundary layers in the vane set of the flow pass section, on the surfaces of the internal cavity between the outer and the inner casings and the metal used for the diaphragm rim and the internal casing. The steam medium in the clearances was considered without taking into consideration the radiant heat exchange between the casing surface and the rim surface, and the thermal resistance of bearing surfaces was determined taking into consideration their roughness. Boundary conditions on the surfaces of the clearances and the contact bearing surface of the diaphragm and the casing computed using the considered technique for the nominal operation mode of the turbine can be used as the initial data for the computation of the thermally stressed states of flow section elements.

Keywords:
turbine, crown of diaphragm, flow part, limit criterion, heat resistance.

Goloshchapov V.N., Kotulskaya O.V., Paramonova T.N. Peculiarities of the Heat Exchange in the Clearance between the Diaphragm Rim and the Turbine Casing. NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 112-116.

This paper gives consideration to the methods and models of the optimal distribution of loadings among energy generating facilities, in particular the method of dynamic programming; two-step method of the optimal distribution of loadings among the energy blocks using the so-called special reference points; methods and models in which the form of the fuzzy description of the factors of the data uncertainty is based on the theory of fuzzy sets; methods and models of the excess of versions; methods and models of relative increments in the fuel flow rate and their combinations; the heuristic method of the solution of the problem of the loading distribution using the limitations of the minimum and maximum electric loadings of energy blocks; the optimization method of the projection of the Rosen gradient, etc. Advantages and drawbacks of the methods and models were shown. It was shown that the methods and models used for the optimization of the distribution of loadings among energy generating facilities require improvement, which makes the development and improvement of the mathematical and algorithmic software used by the automated systems of the control of technological processes of the energy blocks of nuclear power stations and thermal power stations a vital problem.

Keywords:
optimization, mathematical model, method, and the loading distribution

Efimov A.V., Potanina T.V., Kuhtin D.I., Kavercev V.L., Garkusha T.A. Analyzing the Methods and Models Used for the Optimal Distribution of Loadings among Energy Generating Facilities . NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 117-123.

A mathematical model for the computation of the heat exchange in the heat accumulation elements of the regenerative heat exchangers of energy and heat supply systems for high temperature heat process units has been presented. The model allows us to obtain the design data about the operation parameters of the regenerators, nozzle temperature state, and a change in heat carrier parameters. The obtained data can be used for the selection of structural and mode-related parameters for the regenerators both during the reconstruction of available systems and while designing new systems of energy and heat supply for high temperature heat process units.

Keywords:
regenerative heat exchanger, heat process unit, and the mathematical simulation

Koshelnik A.V., Lavinskiy D.V., Havin E.V., Pavlova V.G., Gordienko E.P. Developing the Mathematical Model of Regenerative Heat Exchangers for Energy and Heat Supply Systems of High Temperature Heat Process Units . NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 124-131.

This paper gives the data of the numerical investigation of full temperature separation that occurs in the energetically separated flows of the compressed liquid. The most vivid example of the separation development can be the process of the separation of air into cool and hot flows in the Ranke-Hilsch vortex tube. To carry out CFD investigations we used the program created and verified by the state-owned company \\\”Ivchenko-Progress\\\”. As a basis for the numerical model we used the solution of Reynolds-averaged Navier-Stokes equations (RANS) written for the cylindrical coordinate system. The computations done showed that the distribution of the full temperature in nonviscous and viscous gas flows occurs actually at identical temperature difference; therefore the further investigation was carried out for the nonviscous flow of the ideal gas. Based on the data of the numerical simulation and the analysis of the equations of the laws of the conservation of the ideal gas we made certain inferences on the reasons for the redistribution of full temperature.

Keywords:
full temperature separation, and the compressed liquid

Kukhtin Yu.P., Slynko G.I. Numerical Investigation of the Separation Phenomenon of Full Temperature in Compressed Liquid Flows. NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 132-140.

Consideration is given to the influence produced by the additional heat insulation of buildings on thermal losses in the pipelines of microdistrict heating network. A change in thermal losses depending on the priority of the heat insulation of microdistrict buildings has been analyzed. It has been shown that a decrease in the estimated heat load of the buildings for which the heat insulation is provided results in a decrease of heat losses in microdistrict network pipelines. It has been established that from the point of view of a decrease in thermal losses in network pipelines it is reasonable to provide with the heat insulation first the buildings that are more remote from the central thermal station for the efficient step-by-step heat insulation work over several seasons. While selecting the option of the heat insulation for the buildings of one of the network branches it is recommended to take into consideration the fact that total heat losses in the heating network will be lower if the heat insulation is provided for the buildings connected to a longer branch.

Keywords:
district heating, heat losses, the heat insulation of buildings

Aleksahin A.A., Boblovskij A.V., Ena S.V. Thermal Losses in the Pipelines of Microdistrict Heating Network under Conditions of Changed Thermal Load in Buildings . NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 154-156.

The industry of the construction materials is characterized by an ample amount of thermal treatment processes that produce a significant influence on the quality and cost price of the products manufactured by the company. However, the most efficient method of speeding-up the concrete hardening process remains today the thermal treatment, which allows the concrete to reach the required strength within few hours. Thermal treatment is carried out using different heat carriers, including water steam, the combustion gases and ambient air mixture, electric heating, electrical curing, etc. The scientific paper presented by the authors is devoted to the studies of the efficiency of electric carriers used by thermal plants for the thermal treatment of concrete products. Theoretical and calculated investigations carried out by the authors allowed them to establish that the efficient energy carrier for the thermal treatment of reinforced concrete products is presently considered to be the electric energy.

Keywords:
thermal treatment, energy carriers, flow rate, concrete and the power efficiency

Shulgin Yu.V., Zhnitov Ya.V. Studying the Opportunities of the Energy Saving Using Reinforced Concrete Production Technology FlowVision . NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 157-161.

Computational investigations of the resource characteristics of the high temperature casing elements of a steam turbine allows for the control of the residual resource. The control over the residual resource is exercised by changing operation modes, improving thermal circuit, removal of the damaged metal, changing the structure during the equipment overhaul, etc. The supply of hot steam from neighboring energy blocks to the front end seal of HPC and IPC of the steam turbine K-200-130 LMZ will result in the improvement of the resource characteristics of high and intermediate pressure casings by more than 50 %.

Keywords:
resource control, residual resource, high temperature elements of the steam turbine, casing, high pressure cylinder, intermediate pressure cylinder, and the thermal circuit of the thermal power station.

Chernоusenko О.Yu., Peshko V. A. Establishing Control over the Resource of the Casing Parts of Steam Turbines . NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 26-31.

This paper gives consideration to the use and updating of the integrated software DNA required to simulate the thermal schemes of steam turbine plants. The DNA advantages and drawbacks were analyzed in comparison with the similar software. The main objective of this paper was to develop new models of thermal scheme components using this integrated software based on the available programs and to simulate the thermal scheme of one of the modifications of the turbine plant K-300-240. Developed models provided an opportunity to simulate the thermal scheme of the turbine plant with all required elements and parameters. Initial data files were generated using the language of input parameters of DNA for the two options of the problem statement: thermal scheme with already available models and new models of the elements that were created on their bases. The use of new models of the elements allowed us to considerably approximate the simulation data to computational data obtained by PJSC “Turboatom”. The prospects for further development of this trend were defined.

Keywords:
DNA, STP, simulation, thermal circuit and the modification

Boiko A.V., Usaty A. P., Shapovalova N. S. Updating the Integrated Software DNA to Design STP Thermal Schemes. . NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 44-49.

Recently different methods of the profiling of oval, elliptic, drop-like, flat-&-oval and other pipes have widely been used for the external intensification of the heat exchange including those used for the creation of artificial roughness (ribs, lugs, sand roughness, etc). This paper gives consideration to the design of spherical cavities on the tube surface. For this purpose we designed the experimental bench and carried out test studies. The experimental investigations of the average heat exchange and hydrodynamic resistance that occur during streamline of the bundle of tubes with spherical cavities on the surface were carried out. Heat emission coefficients and hydrodynamic resistance (Euler number) coefficients were obtained for the first row of the bundle of circular tubes with cavities for the transverse streamline.

Keywords:
heat exchange, hydrodynamic resistance, tube bundles. and spherical cavities

Khalatov А.А., Meyris A. Zh., Donyk T. V., Gamretska A. V. Thermal Exchange and Hydrodynamic Resistance at the Transverse Air Streamline of the First Row of the Bundle of Tubes with Spherical Cavities . NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 50-53.

As of today the development of the CFD-method that would allow us to find the accurate solution for the inverse problem of the cascade theory has no prospects in the nearest future. Therefore we propose the further development of the classic version of the Q3D- approach for which we assume the current motion in the layers on stream surfaces S1 and S2 and the use of the Euler equation and the solution search process will be iterative. The advanced method of the solution of the inverse problem for the stream on the surface S2 has no axial symmetry and the problem is solved for the layer of a variable thickness using new forms of discontinuity equations and the equations of the amount of motion. The surfaces S1 are arbitrary twisted, and the 3-D flow is reduced to the 2-D flow with no assumption that the radial component of the velocity and all the derivatives in the radial direction are homogeneous and retain their values that correspond to the solution of the problem for the surfaces S2. The inverse problem of the theory of cascades is solved step-by-step. At the first stage the geometry of two adjacent surfaces S2 that form the layer of a variable thickness, for example in the middle of the channel, is prescribed and the meridional contours of the root and the periphery of the interblade channel for this layer are defined. At the second stage the problems are solved for S1 surfaces that can be twisted. At the third stage we performed the volumetric profiling of the blade using determined geometric characteristics of the interblade channel.

Keywords:
rotating cascade, ideal gas, motion quantity equation.

Subotovich V. P., Yudin A.Yu. Axial Symmetry-Free Flow through the Rotating Cascade of the Turbine Machine on the Stream Surface S2 . NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 78-81.

Due to the abrupt rise in prices for energy carriers the population shows a great interest in the integration of alternative heat sources into the heat supply systems of the buildings. One of the most efficient solutions is considered to be the placement of the thermal pump in parallel with the gas boiler. In this case it is necessary to take into consideration the factors that influence the heat pump operation efficiency in the entire heat supply system. At the moment we are facing the problem of the integration of renewable heat sources in heat supply systems without taking into consideration the operation modes of the heating system. This circumstance results in the degradation of microclimate parameters in the room, and in addition disputes and conflicts with the mounting organization arise. This paper gives consideration to the problem of the introduction of thermal pumps into available heat supply systems. The factors that affect the efficiency of the use of the outdoor air by thermal pumps integrated into the available heat supply system have been given. Consideration is also given to the limitations of the use of one-stage thermal pumps for available heating systems. The data of the comparative computation of technical and economic indices of the use of two types of thermal pumps with and/or without gas boiler have been provided.

Keywords:
thermal pumps, combined heat supply systems.

Balasanian G. A., Klimchuk A. A., Minyailo M.B. Optimal Power of the Thermal Pump Used for Combined Heat Supply Systems in the Southern Regions of Ukraine . NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 108-111.

The comparison data of different options of the internal use of the heat of effluent combustion products during the operation of high temperature thermal process plants (HTTP) have been given. The main factors that affect the efficiency of the heat use during the operation of HTTP have been defined. On the bases of balance equations the methods of the computation of the fuel saving at the preliminary material heating and the heating of burning components due to the regeneration of heat of effluent combustion products have been given. The influence of a coefficient of heat regeneration and a coefficient of the efficiently used heat of the working chamber on the value of the relative heat of effluent combustion products (appropriate diagrams and design ratio are given) was shown. The conclusion section gives the recommendations for the selection of the efficient method for the internal use of the heat of combustion products effluent from the working chamber from the standpoint of an increase in the HTTP productivity and fuel saving.

Keywords:
fuel saving, furnace, combustion products and the recuperation

Dimitrov A.D., ShramenkoA.N., Piadukhov V.A. Increasing the Efficiency of the Fuel Use for Industrial Furnaces . NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 141-146.

Labyrinth seals used by modern high-power steam and gas turbines occupy a considerable portion of the rotor surface and casing components. For example, the labyrinth seals of the high-pressure cylinder of the steam turbine operated by PJSC “Turboatom” K-325-24.5 take up 60 % of its length. Hence, for the appropriate identification of the thermal, thermally stressed and thermally strained state of the high pressure parts of such turbines we need to have more accurate data on the boundary conditions of the heat exchange in labyrinth seals. This is of great importance for the mathematical simulation whose purpose is to search for the optimal start –up schedule of high power steam turbines from different initial states. In the paper, mathematical modeling of fluid flow and heat transfer in in-line flow and stepped labyrinth turbomachinery seals was carried out using an application package. Comparison of the results with physical experiments have shown the adequacy of modeling and the ability to use it in solving specific engineering problems.

Keywords:
turbomachines, labyrinth seals, hydrodynamics, heat emission, and the mathematical simulation.

Pustovalov V.N., Fatich L.V., Naumenko S.P. Mathematical Simulation of the Medium Flow through the Labyrinth Seal of the Turbomachine . NTU «KhPI» Bulletin: Series «Power and Heat Engineering Processes and Equipment». 2015. No. 16. Pp. 147-153.