Global Energy

SCO RUS 8-10 7102629343 Peter the Great St. Petersburg Polytechnic University, Russia Vasil'ev Yuriy interserv@spbstu.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

THE WORK OF THE SCIENTIFIC PART OF SPbPU IN THE FIELD OF COMPRESSOR ENGINEERING (to the 85th anniversary of the head of the laboratory «Gas dynamics of turbomachines» professor Yu.B. Galerkin and the 5th anniversary of the laboratory) The article is devoted to the role and achievements of the science school of compressor engineering, established at the Leningrad Polytechnic Institute (now St. Petersburg polytechnic university of Peter the Great) by a prominent scientist, K.P. Seleznev. Now, this direction is being developed at the Gas Dynamics Laboratory of Turbomachines at SPbPU under the supervision of Professor Yury Borisovich Galerkin. The article is introductory to the selection in the same issue of the journal a collection of works by laboratory staff, their fellow scientists from other organizations, as well as industry workers presenting a modern picture of research on compressor technology. 10.18721/JEST.24401 621:515 compressor turbomachines gas dynamics laboratory Petersburg polytechnic school of compressor engineering https://engtech.spbstu.ru/article/2018.106.1/ 1_Vasilev.pdf

RAR RUS 11-23 Semenovskiy Vasilii B. swb@neva.ru MODEL STAGES FOR CENTRIFUGAL COMPRESSORS IN TURBOEXPANDER UNITS The gas dynamic characteristics of 8 single-stage centrifugal compressors of turboexpander units have been approximated with great accuracy by the equations of the new version of the mathematical model of the Universal Modeling Method and have been included in the database of model stages. The universal set of empirical coefficients of the model is somewhat modified for each of the compressors, whose dimensionless gas-dynamic characteristics lie within a fairly wide range. The families of characteristics are calculated by varying the similarity criteria for compressibility. The influence of surface roughness has been investigated, revealing the presence of self-similarity according to the Reynolds criterion. The loss coefficients of the impeller, the vaned diffuser and the exit nozzle are given for two model stages. The database and computer programs of the Universal Modeling Method make it possible to use the characteristics of model stages for designing compressors by the method of approximate gas dynamic similarity. 10.18721/JEST.24402 621.515 centrifugal compressor turboexpander vaned diffuser model stage mass flow rate work coefficient surface roughness https://engtech.spbstu.ru/article/2018.106.2/ 2_Semenovskiy.pdf

RAR RUS 24-38 Rekstin Bakaev Boris V. VARIANT CALCULATIONS FOR INDUSTRIAL CENTRIFUGAL COMPRESSORS BASED ON SIMPLIFIED MATHEMATICAL MODEL Variant calculation is the first step in gas dynamic design. The study provides brief information on the simplified mathematical model of efficiency and basic equations for estimating the efficiency and basic parameters of compressors. It is possible to compare the variants of compressors with a different number of shafts and rotation frequencies, with a different number and location of gas coolers in the flowing part, with different types of impellers and diffusers. Examples of a variant calculations are given for two types of compressors of a linear gas compressor unit and of a compressor for underground gas storage. It is shown that single-shaft compressors for underground gas storages should be optimized by selecting the maximum possible number of stages, by selecting the ratio of loading factors and the diameters of the impellers. It is shown that the single-shaft scheme of a general-purpose air compressor is inferior in efficiency to a two-shaft scheme with a large number of intermediate cooling. 10.18721/JEST.24403 621.515 centrifugal compressor mathematical model conditional flow coefficient pressure ratio efficiency https://engtech.spbstu.ru/article/2018.106.3/ 3_Rekstin.pdf

RAR RUS 39-50 Peter the Great St. Petersburg polytechnic university Kotlov Andreii Maksimenko Maksimenko I. A. «Compressor» Kuznetsov Yurii INFLUENCE OF PROFILE GEOMETRY ON THE PERFORMANCE OF A CLAW COMPRESSOR Dry (non-lubricated) claw compressors have a promising future because they possess the advantages of both piston and rotary compressors. The rotor profiles have sophisticated form including several curves of similar type, combined so that the line of contact is always parallel to the rotor axis. We have considered the effect of the main geometric parameters of the profile (R, αR and r) on the rotor-swept area value, on the volume of the cavity and on the amount of leakage through the clearances. The study has been carried out by the developed computer program intended for selecting the optimal variant for the ratio of geometrical parameters of the profile. We have given the results of theoretical studies on the influence of the profile’s geometric parameters on integrated characteristics of a rotor-geared compressor. We have presented optimal relations between the parameters defining the geometry of gas distribution elements. 10.18721/JEST.24404 621.514 claw compressor rotor profile gas leakage mathematical model optimization https://engtech.spbstu.ru/article/2018.106.4/ 4_Kotlov.pdf

RAR RUS 51-60 Peter the Great St. Petersburg polytechnic university Kotlov Andreii MATHEMATICAL ANALYSIS OF OPERATION OF A TWO-STAGE PRESSURIZED COMPRESSOR DESIGNED TO COMPRESS METHANE Ensuring efficient and reliable operation of reciprocating compressors in a wide range of operating parameters is one of the most important problems in design, manufacture and operation of compressor equipment. Reciprocating compressors, working as part of mobile automotive gas refuellers, are intended for compressing natural gas to a final pressure of 20–25 MPa. The task in designing such equipment is to determine the real properties of the compressible medium. We have carried out a theoretical study on the influence of initial gas parameters on the operation of the compressor. We have given the results for operation of the compressor both for compression of an ideal gas and for a real gas. The developed mathematical model and the method for determining the thermodynamic properties of methane have been briefly described, with the results of comparison of calculated and tabulated data given. The results of testing the mathematical model for adequacy have been presented. 10.18721/JEST.24405 621.512 reciprocating compressor real gas methane mathematical model valve https://engtech.spbstu.ru/article/2018.106.5/ 5_Kotlov.pdf

RAR RUS 61-71 Smolensk state agricultural academy Nikiforov Aleksandr G. nikiforof@mail.ru Avramenko Dariia Yu. PREPARING EXPERIMENTAL DATA FOR NEURAL NETWORK MODELING OF CENTRIFUGAL COMPRESSOR PERFORMANCE The paper presents generalized information on possible methods for preliminary processing of initial data and the efficiency of these methods for training neural network models. Differentcombinations for processing the initial sample, as well as different types of activation functions and architecture of neural networkscan be selecteddepending on the simulation goals and the specifics of the subject area. The efficiency of preliminary data processing has been established with neural network models of energy characteristics of centrifugal compressors. Eliminating outliers in the experimental data and normalizing the initial data allowedto increase the accuracy of the model by 1,5 % compared with the model trained on non-normalized data. The importance of processing and preparing data is confirmed by findings of foreign studies using data preprocessing to create neural network models in different subject areas. 10.18721/JEST.24406 621.51(06) artificial neural networks neural networks centrifugal compressors loss coefficient friction coefficient efficiency pressure intermediate centrifugal compressor stage vaneless diffuser. https://engtech.spbstu.ru/article/2018.106.6/ 6_Nikiforov.pdf

RAR RUS 72-79 Ishmuratov Maksim A. Ibragimov Evgenii R. Nalimov Viktor N. Paranin Yurii A. EVALUATION OF PARAMETERS OF A SPIRAL EXPANDER Solving the problems of energy saving at gas distribution points, namely, the problems of electricity demand for a facility’s own needs, is an urgent task that can be solved using a spiral expander. The energy of the transported gas pressure is transformed in the expander into mechanical energy, and the mechanical energy obtained in the expander can be converted into the electrical energy in a generator that is connected to the expander. We have considered a spiral compressor, which is a reversible machine operating in the mode of a spiral expander. The results of experimental studies of the spiral expander are presented. We have given mechanical characteristics, such as the power output by the shaft, the compressed gas flow rate for the range of the expansion ratio and the rotational speed. To determine these characteristics, an experimental stand was designed and manufactured. We have analyzed the presented parameters and compared them with the characteristics of screw expanders. 10.18721/JEST.24407 621.521 spiral expander mechanical characteristics temperature difference expansion ratio rotational speed adiabatic efficiency https://engtech.spbstu.ru/article/2018.106.7/ 7_Ishmuratov.pdf

RAR RUS 80-89 Busarov Sergei S. Yusha Vladimir L. PROSPECTS FOR CREATING LOW-FLOW COMPRESSOR UNITS WITH MEDIUM AND HIGHPRESSURESBASED ON UNIFIED LOW-SPEED LONG-STROKE STAGES Creation of low-speed long-stroke compressor units has now made it possible to obtain quasi-isothermal stages with temperatures of injected gas up to 450K and pressures of one stage up to 12 MPa. The alternative replacing low-flow membrane and multistage compressor units with low-speed ones, offered in this paper, should allow to reduce the weight and size parameters of the unit as a whole by obtaining high pressure in one compression stage. However, unification of such stages for creating multi-cylinder units based on low-speed long-stroke stages has not been discussed until now. The example given in this paper allows to obtain a unified series of low-speed stages for a limited range of parameters. Further development of the unification theme is possible only with the help of optimization methods; extensive experimental and theoretical datahave to be obtained for this purpose. 10.18721/JEST.24408 62-97/-98 piston compressor mathematical model discharge temperature unification isothermal efficiency parametric analysis https://engtech.spbstu.ru/article/2018.106.8/ 8_Busarov.pdf

RAR RUS 90-96 Nikulin Nikolai K. Svichkar Elena V. Klyucharov Vladimir S. EXPERIMENTAL DETERMINATION OF OPERATIONAL SPEED OF A MOLECULAR VISCOUS STAGE OF A VACUUM PUMP We have experimentally investigated the evacuating characteristics of a molecular viscous stage of a combined turbomolecular pump. This study has been conducted for a stage with trapezoidal channels operating in viscous or transient regimes of gas flow. The paper describes the experimental stand used to obtain the experimental data, namely, measured speed of the pump in a wide range of pressures. The obtained experimental data have been used to analyze the influence of the velocity parameters of the pump stage on its operational speed. The ways of increasing the operational speed of the pump have been determined without changing the overall dimensions of the pump as a whole. The obtained results allow to improve the evacuating characteristics of combined turbomolecular vacuum pumps and the parameters of the high-vacuum system where they are installed. 10.18721/JEST.24409 81.29.14 molecular viscous stage MWN hydraulics experimental study evacuating parameters vacuum pump pump operational speed https://engtech.spbstu.ru/article/2018.106.9/ 9_Nikulin.pdf

RAR RUS 97-105 Ivanov Nikolai G. 7102545375 Peter the Great St. Petersburg Polytechnic University, Russia Kirillov Alexander ai_kirillov@mail.ru, tot@pef.spbstu.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

Smirnov Evgeny Iaroslavtceva Nadezhda A. VORTEX CELL AS A MEANS OF IMPROVING THE EFFICIENCY OF AN ANNULAR AXIAL-RADIAL DIFFUSER The paper provides an explanation why new methods of reducing kinetic energy losses have to be developed for annular axial-radial diffusers with a sharp turn of the stream, used in exhaust hoods of condensing steam turbines. The results of numerical simulation of separated flow in an annular axial-radial diffuser with vortex cells intended for control of flow separation are presented. Numerical simulation is based on the solution of the Reynolds-averaged Navier–Stokes equations in a steady axisymmetric formulation. The efficiency of the vortex cell is estimated depending on its size, location on the surface of the diffuser near the flow separation zone and the intensity of the slit suction. The conclusion is that the vortex cell with a slit suction can be regarded as a promising method for controlling flow separation in an axial-radial diffuser with a sharp turn of the stream. 10.18721/JEST.24410 621.165-532.517 axial-radial diffuser flow separation numerical simulation vortex cell boundary layer suction https://engtech.spbstu.ru/article/2018.106.10/ 10_Ivanov.pdf

RAR RUS 106-117 Averyanova Olesya V. POSSIBILITIES OF USING HEAT PUMP SYSTEMS WITH A WATER LOOP IN RUSSIAN FEDERATION The paper presents a procedure for calculating the annual energy consumption of a large construction object whose heating system comprises heat pumps connected in a water loop and offers a zone map of the Russian Federation depending on the potential efficiency of using water-loop heat pump systems. We have considered the traditional system with heating units and cooling fan coil units and the proposed new system with water-loop heat pumps. The procedure for calculating the energy consumption of these systems is described. Based on this procedure, we have calculated the coefficient of relative energy efficiency of using water-loop heat pump systems for Russian Federation and constructed a zone map of Russian Federation depending on the potential efficiency of using these systems. We have analyzed the energy efficiency of water-loop heat pump systems for large construction objects. The proposed procedure and the zone map are applicable for calculations of annual energy consumption of heating systems with heat pumps included in the water loop and can be recommended as a tool for choosing the circuit design. 10.18721/JEST.24411 696:697 heat pump energy consumption large construction object heating system methodology of сalculation zone map https://engtech.spbstu.ru/article/2018.106.11/ 11_Averyanova.pdf

RAR RUS 118-131 Lyutikova Marina N. Nekhoroshev Sergei V. Kulkov. Mikhail G. DIAGNOSTICS OF INTERNAL ISOLATION IN HIGH-VOLTAGE EQUIPMENT BY CHROMATOGRAPHY AND MASS SPECTROMETRY Currently, preventive diagnostics of internal isolation in high-voltage equipment is of great importance for timely detection of defects and making the right decision to eliminate them. One of the main components of insulation are transformer oils of different brands. The article gives an overview of the chemical composition of mineral insulating oils established by various studies. In this paper, we present the results of studying the aging products of the most used brands of transformer oils (GK, TKp, T-750, Nytro 11GX, Nytro 10X) used in real operating conditions of electric grid equipment. Oxygen-containing compounds, saturated hydrocarbons, saturated and unsaturated carbocyclic hydrocarbons, as well as derivatives of naphthalene and anthracene series were identified by gas chromatography with mass-selective detection. An explanation of their origin is given. Attention is drawn to the fact that some compounds of liquid mineral dielectrics can be indicators for assessing the state of the «oil-cellulose» insulation system in high-voltage equipment. 10.18721/JEST.24412 621.314.212: 621.315.61 mineral insulating oil hydrocarbon oxidation oil aging gas chromatography with mass-selective detector https://engtech.spbstu.ru/article/2018.106.12/ 12_Lyutikova.pdf

RAR RUS 132-140 Manzhula Konstantin FATIGUE STRESS IN MAIN BEAMS OF SPAN-TYPE CRANES This article presents calculated dependences for estimating stresses in the main beams of span-type cranes, which are necessary for fatigue resistance and residual life computations. The dependences are obtained by forming typical technological cycles of crane operation according to the predicted or actually recorded parameters of its motion. The dependences allow to calculate the largest, smallest, and average stresses during unsteady operation of mechanisms for lifting and moving the crane and trolley, taking into account the coefficients of dynamism and damping of oscillations. Assumptions and limitations, which are used for the calculated dependences of typical technological cycles, are formulated. We have established by calculation that the first 6–7 damped oscillations in the vertical plane and 5–6 oscillations in the horizontal plane, depending on the bridge design, have a damaging effect. An example of a typical technological cycle and the resulting stress pattern is shown. 10.18721/JEST.24413 621.01/.03 : 621.86/.87 span type cranes fatigue stresses fatigue resistance of metal structures typical process cycle https://engtech.spbstu.ru/article/2018.106.13/ 13_Manzhula.pdf

RAR RUS 141-149 Volkov Andrey automats@inbox.ru Matsko Olga N. Mosalova Anna V. SELECTING THE ENERGY-SAVING LAWS OF MOTION FOR MECHATRONIC DRIVES OF PRODUCTION MACHINES In this paper, we have developed digital models of mechatronic drives for robots and production machines for the most common laws of acceleration variation and typical loads. The examples show that there is a minimum peak instantaneous power in the areas of acceleration and dynamic braking at certain values of additional parameters for all motion laws under consideration and for the given cycle time and travel. Such parameters include the acceleration/deceleration times, the coefficient of exceeded minimum possible acceleration or the coefficient of uniform motion. Based on studying mathematical models, we have proposed methods for assessing the effectiveness of selecting motion laws and their parameters with respect to the lowest maximum power consumption. The relationship between the maximum instantaneous power and the drive power consumption for different motion laws has been established. 10.18721/JEST.24414 621.01, 621.08, 62-52 energy saving mechatronic drive maximum instantaneous power motion laws comparative analysis cyclic drives https://engtech.spbstu.ru/article/2018.106.14/ 14_Volkov.pdf

RAR RUS 150-159 Ilyinykh Viktor A. INFLUENCE OF CONICAL PROFILE CONNECTIONSONACCURACY AND RIGIDITY OF TECHNOLOGICAL SETS OF MULTI-PURPOSE MACHINES The article presents the study of technological sets of multi-purpose machines based on conical P-3 profile connections for accuracy and rigidity. Based on previously constructed mathematical models of P-3 profile surfaces of the shaft and the sleeve hole,we have performed multiple simulations on coupling of conical connection details. We have analyzed the accuracywith which theshaft with the main elements (drills, cutters, boring tools) was installed in the sleeve hole for six coordinates (3 displacements and 3 rotations). Subsequently, the assembled connection was loaded by an external force, allowing to obtainthe value of elastic deformation (a change in the position of the shaft in the sleeve hole) also for six coordinates. In each case, we havecompared the accuracy of mutual positions of the parts ofP-3 profile and round connections bothin the assembly of the connection as well during its operation by an external force. The main conclusions have been also formulated. 10.18721/JEST.24415 62-25 P-3 profile interference tooling systems multi-purpose machines https://engtech.spbstu.ru/article/2018.106.15/ 15_Ilinih.pdf

RAR RUS 160-168 Zlobina Irina V. STUDYOF MICROSTRUCTURE OF ARAMID FABRICS FOR CONSTRUCTIONAL AND PROTECTIVE ORGANOPLASTICSMODIFIED IN A MICROWAVE-FREQUENCYELECTROMAGNETIC FIELD Organoplastics have recently become widely used in aeronautical engineering as structural materials and means of protecting critical units (engines, control systems) from damaging factors due to their lightness and strength. The microstructure of the samples of the aramid fabric TSVM-J, subjected to a microwave-frequency electromagnetic field of an average power level at a frequency of 2450 MHz was investigated. A significant change in the contact conditions of individual filaments at the level of interfibril bonding of fibers has been found, which is expressed in the aggregation of fibrils into agglomerates filling the gaps between the fibers with increasing interaction area and in the convergence of individual fibers, which increases the reliability of intermolecular bonds. The obtained results can be used as one of the mechanisms for increasing the strength characteristics of structural organoplastics and protective materials from aramid tissues after microwave exposure. 10.18721/JEST.24416 621-039-419; 620.22-419; 537.868 organoplasty ballistic materials aramid fabrics microwave oven electromagnetic field microstructure fibers fibrils activation agglomerates https://engtech.spbstu.ru/article/2018.106.16/ 16_Zlobina.pdf

RAR RUS 169-184 56035034600 Peter the Great St. Petersburg Polytechnic University, Russia Tsemenko Valeriy plast-ftim@mail.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

Ganin Sergey Zamozdra Maksim Yu. MECHANICAL PROPERTIES OF BILLETS PRODUCED BY HOT EXTRUSION OF MAGNESIUM CHIPS The process of billets producing from the magnesium alloy chip MA5 by hot extrusion was studied and realized. The process was realized at heating temperatures of 300, 350 and 400°C with average extrusion coefficients of 9, 13 and 24. In the process of hot extrusion occurred compaction in the matrix of blanks produced by cold pressing of chip particles; destruction of oxide films on the surface and distribution throughout the volume of the workpiece dispersed oxide particles during the plastic flow of the material through the die. As a result of the processes of recrystallization and deformation hardening, the intensity of which was determined by the temperatures and the coefficients of extraction, the structure of the material was formed. It is found that the degree of plastic deformation and the temperature of the extrusion process have an ambiguous effect on the mechanical properties of the workpieces in static tests for tension and compression, a certain role is played by the residual porosity. The strength characteristics of the obtained billets are slightly higher than the strength of the deformed cast billets from the MA5 alloy, however, lower in plasticity. 10.18721/JEST.24417 621.762:669.018.28:669.721.5 powder metallurgy chip processing magnesium alloys hot extrusion mechanical properties https://engtech.spbstu.ru/article/2018.106.17/ 17_Tsemenko.pdf

RAR RUS 185-195 Morachevski Andrey morachevski@mail.ru Popovich Anatoliy popovicha@mail.ru Demidov Alexander ph-chem@ftim.spbstu.ru PROMISING ANODE MATERIALS FOR SODIUM-ION BATTERIES The brief review considers the findings of the studies dedicated to anode materials for sodium-ion batteries published mainly in 2012–2017 almost exclusively in foreign periodicals. Due to a huge amount of studies in this area, we have primarily considered review papers, citing only a few original works. The principle of operation of sodium-ion batteries is the same as lithium-ion batteries: as the battery is charging, sodium ions from the material of the positive electrode (cathode) pass into the electrolyte and then interact with the material of the negative electrode (anode). Reverse processes occur during discharge. The main advantage of sodium-ion battery in comparison with the lithium-ion battery is the low cost of raw materials and their wide availability. However, there are also difficulties associated primarily with the large size of sodium ions. Perspective anodic materials of different types are considered in the study. 10.18721/JEST.24418 621.355 sodium-ion batteries anode materials electrode processes https://engtech.spbstu.ru/article/2018.106.18/ 18_Morachevskiy.pdf

RAR RUS 196-204 Burakova Elena mashtatpetr@mail.ru Melezhik Aleksandr V. Gerasimova Alena V. OBTAINING SUSTAINABLE DISPERSIONS OF GRAPHENE NANOPLATELETS This paper shows the possibility of using phenol-formaldehyde resin (PFR) as a surfactant in obtaining stable dispersions of graphene nanoplastic (GNP). Dispersion of oxidized GNP in an aqueous medium at 50 °C in the presence of PFR allows to obtain stable colloidal dispersions with a concentration of up to 1 %. The maximum concentration of GNP in an aqueous solution is observed at a mass ratio of 2: 1 graphene / dry residue of PFR. The resulting dispersions of GNP translated into acetone or isopropanol can be used as modifiers of epoxy resins. The advantage of using PFR as a surfactant is the absence of the need to remove it from the GNP-based nanocomposite. A preliminary experiment showed the possibility of using the obtained dispersions as an initial component in the process of synthesizing a porous carbon / GNP nanocomposite with a specific surface area of 2300–2500 m2 / g. 10.18721/JEST.24419 544.032.72; 675.043.42 graphene nanoplatelets; dispersion surfactant phenolformaldehyde resin nanocomposite https://engtech.spbstu.ru/article/2018.106.19/ 19_Burakova.pdf