Management of thermal and mechanic flow characteristics in the output channels of a turbocharger centrifugal compressor

It is known that the thermal and mechanical characteristics of the air flow in the output channel of a turbocharger compressor largely determine the effectiveness of the gas exchange processes quality of a piston engine. The studies were carried out on an experimental installation containing a turbocharger, output channels of different configurations, a measuring base, and a data collection system. It was found that stabilization of the flow in the compressor output channel leads to a significant increase in heat transfer intensity (up to 25 %) compared to the baseline pipeline while simultaneously reducing the turbulence number by up to 30 %. A more significant increase in heat transfer intensity (up to 30 %) was observed in the output channel of the compressor with grooves compared to the base channel while simultaneously increasing the turbulence number by up to 12 %. The proposed configuration of the output channels of the compressor can be used to intensify heat transfer for the natural cooling of the air during the intake process. The configuration with a leveling grid can be used to stabilize the gas-dynamic flow parameters in order to reduce the hydraulic resistance of the intake system of a turbocharged engine. © Published under licence by IOP Publishing Ltd.Russian Science Foundation, RSF: 18-79-10003The work has been supported by the Russian Science Foundation (grant No. 18-79-10003)

Method of stabilizing pulsating gas flows in the intake system of a piston engine with turbocharging

Piston internal combustion engines (ICE) are the most common sources of energy among heat engines. Currently, most ICEs are equipped with a turbocharging system. Thermomechanical perfection of processes in the intake system largely determines the efficiency of engines. This article proposes a method of stabilizing the pulsating flows in the intake system by installing the leveling grid in the output channel of the turbocharger (TC) compressor. Studies were conducted on an experimental setup, which consisted of a single-cylinder engine and turbocharging system. A constant-temperature thermo-anemometer was used to determine the instantaneous values of the air flow rate and the local heat transfer coefficient. It has been established that the presence of a leveling grid in the intake system leads to a decrease in the turbulence number by up to 25% compared with the basic intake system (while maintaining the flow characteristics). It is shown that the installation of a leveling grid in the intake system of the ICE with TC also leads to a decrease in the heat transfer intensity by up to 15 % compared to the base system. The obtained data expands the knowledge base on the thermomechanics of pulsating flows in hydraulic systems of complex configuration. © 2019 Institute of Physics Publishing. All rights reserved.Russian Science Foundation, RSF: 18-79-10003The work has been supported by the Russian Science Foundation (grant No. 18-79-10003)

Peculiarities of simulation of thermo - stressed state of stop valve of steam turbine registration plasticity of material

The reliable performance of the shut-off valve determines the operability of the entire power unit. The sequence of calculation and analysis of the thermally stressed state with allowance for ductility is given on the example of the stop valve of the steam turbine T-110 / 120-130 UTZ. The necessity of carrying out nonlinear calculations taking into account plasticity according to the bilinear deformation diagram for the stage of heating the stop valve during the start of the steam is proved. Two variants of calculations are fulfilled: constraints in the problem of the stress-strain state of the stop valve: in the first: restrictions are set on the movement of the internal surface of the channel for the valve stem and in the zone of welding of the drainage; In the second one, a hard seal on the cover of the stop valve is designed to simulate the deformation of the channel for moving the rod.Надежная работоспособность стопорного клапана определяет работоспособность всего энергоблока. Приводится последовательность проведения расчетов и анализа термонапряженного состояния с учетом пластичности на примере стопорного клапана теплофикационной паровой турбины Т-110/120-130 УТЗ. Доказана необходимость проведения нелинейных расчетов с учетом пластичности по билинейно диаграмме деформирования для этапа прогрева стопорного клапана во время пуска паровой. Выполнено два варианта расчетов: ограничений в задаче напряженно-деформиванного состояния стопорного клапана: в первом: заданы ограничения по перемещению внутренней поверхности канала для штока клапана и в зоне приварки дренажа; во втором задана жесткая заделкой по крышке стопорного клапана для моделирования деформации канала для перемещения штока

Development of mathematical support of program algorithms for heating of stop valve on the main steam line of steam turbines development of software for a warm-up period, the main steam steam turbines

The reliable performance of the shut-off valve determines the operability of the entire power unit. The sequence of calculation and analysis of the thermally stressed state with allowance for ductility is given on the example of the stop valve of the steam turbine T-110 / 120-130 UTZ. The necessity of carrying out nonlinear calculations taking into account plasticity according to the bilinear deformation diagram for the stage of heating the stop valve during the start of the steam is proved. Two variants of calculations are fulfilled: constraints in the problem of the stress-strain state of the stop valve: in the first: restrictions are set on the movement of the internal surface of the channel for the valve stem and in the zone of welding of the drainage; In the second one, a hard seal on the cover of the stop valve is designed to simulate the deformation of the channel for moving the rod.Актуальное направление совершенствования технологии эксплуатации энергоблоков на ТЭС являются работы по полной или частичной автоматизации пуско – остановочных режимов теплотехнического оборудования. Для этого разрабатывается математическое обеспечение алгоритмов программ непрерывного управления параметрами пара и нагрузкой в переходных энергоблоков. Современные вычислительные устройства и комплексы средств компьютерного инженерного моделирования позволяют объединить локальные модели паропроводов с дренажами и байпасами, стопорных и регулирующих клапанов, корпусов цилиндра высокого давления в турбины в одной задаче термонапряженного состояния. При моделировании процесса на компьютере ограниченной мощности в реальном времени необходимы упрощения

An Expert System for Diagnostics and Estimation of Steam Turbine Components’ Condition

This article describes an expert system of probability type for diagnostics and state estimation of steam turbine technological subsystems’ components. The expert system is based on Bayes’ theorem and permits one to troubleshoot the equipment components, using expert experience, when there is a lack of baseline information on the indicators of turbine operation. Within a unified approach, the expert system solves the problems of diagnosing the flow steam path of the turbine, bearings, thermal expansion system, regulatory system, condensing unit, and the systems of regenerative feed-water and hot water heating. The knowledge base of the expert system for turbine unit rotors and bearings contains a description of 34 defects and 104 related diagnostic features that cause a change in its vibration state. The knowledge base for the condensing unit contains 12 hypotheses and 15 pieces of evidence (indications); the procedures are also designated for 20 state parameters’ estimation. Similar knowledge bases containing the diagnostic features and fault hypotheses are formulated for other technological subsystems of a turbine unit. With the necessary initial information available, a number of problems can be solved within the expert system for various technological subsystems of steam turbine unit: for steam flow path, it is the correlation and regression analysis of multifactor relationship between the vibration and the regime parameters; for thermal expansion system, it is the evaluation of force acting on the longitudinal keys depending on the temperature state of the turbine cylinder; for condensing unit, it is the evaluation of separate effect of the heat exchange surface contamination and of the presence of air in condenser steam space on condenser thermal efficiency performance, as well as the evaluation of term for condenser cleaning and for tube system replacement. With the lack of initial information, the expert system formulates a diagnosis and calculates the probability of faults’ origin