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

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

The Properties of Chromium Steel Overlaying Used as a Hardening Coating for Stop Valve Sealing Surface

AbstractOperational reliability of a pipeline valve depends on the durability of the weld sealing surfaces of the stop device, while the durability of the sealing surface is determined by the coating material properties. To enhance stop valve durability, a new composition for a flux-cored wire was developed, ensuring the generation of the surfacing metal with alloying system Cr-Ni-Mo-Mn-Si-Nb-Ti-B. Such wire provides overall hardening of the coating matrix with carboboride and intermetallic phases, providing an advanced operational reliability of stop valve nodes operating under friction conditions in aggressive environment

Fluid dynamic forces in the main steam pipeline of thermal power plant upon stop valves closure

A steam turbine trip is followed by a prompt closure of stop valves in front of the turbine and consequently to a pressure rise in the main steam pipeline. This steam hammer transient leads to the generation of intensive fluid dynamic forces that act along the pipeline axis and induce additional dynamic loads on the main steam pipeline. It is a common practice to assume a simultaneous closure of all stop valves in the safety analysis of the main steam pipeline. In the present paper computer simulations and analyses of the fluid dynamic forces are performed for several scenarios that take into account the possibility of delayed closure of the stop valve in front of the turbine. The influence of the failure of the steam by-pass line opening is considered too. The results show that the delay of the stop valve closure increases the maximum intensity of fluid dynamic force in the pipeline segment in front of the stop valve and decreases the intensity of fluid dynamic forces in segments along the pipeline. The failure of the by-pass line to open leads to prolonged steam pressure and fluid dynamic forces oscillation in pipeline segments. The simulations were performed with the in-house computer code based on the method of characteristics for the solving of the hyperbolic system of PDE that represent the mass, momentum and energy balance equations of the 1-D, compressible and transient fluid-flow. The obtained results are a support to safety analyses of thermal power plants under transient conditions

Fluid dynamic forces in the main steam pipeline of thermal power plant upon stop valves closure

A steam turbine trip is followed by a prompt closure of stop valves in front of the turbine and consequently to a pressure rise in the main steam pipeline. This steam hammer transient leads to the generation of intensive fluid dynamic forces that act along the pipeline axis and induce additional dynamic loads on the main steam pipeline. It is a common practice to assume a simultaneous closure of all stop valves in the safety analysis of the main steam pipeline. In the present paper computer simulations and analyses of the fluid dynamic forces are performed for several scenarios that take into account the possibility of delayed closure of the stop valve in front of the turbine. The influence of the failure of the steam by-pass line opening is considered too. The results show that the delay of the stop valve closure increases the maximum intensity of fluid dynamic force in the pipeline segment in front of the stop valve and decreases the intensity of fluid dynamic forces in segments along the pipeline. The failure of the by-pass line to open leads to prolonged steam pressure and fluid dynamic forces oscillation in pipeline segments. The simulations were performed with the in-house computer code based on the method of characteristics for the solving of the hyperbolic system of PDE that represent the mass, momentum and energy balance equations of the 1-D, compressible and transient fluid-flow. The obtained results are a support to safety analyses of thermal power plants under transient conditions

Стенд для гидравлического испытания запорной арматуры

THE HYDRAULIC TEST STAND FOR STOP VALVE А. KULBEI, D. KISIALIOYРассматривается проблема гидравлического испытания запорной арматуры. Представлен анализ применяемых на сегодняшний день стендов для испытания. Сформулированы общие недостатки методов. Предложен альтернативный вариант стенда для гидравлического испытания. Описана конструкция стенда в целом и каждого конструктивного элемента в отдельности. Приведена схема проведения гидравлического испытания с использованием альтернативного варианта стенда.= The problem of hydraulic test for stop valve are examine in this article. The modern methods of the hydraulic test stands are analyzed. The authors analyze their and formulate disadvantages. The alternative methods of the hydraulic test stand are suggested. The authors suggest a plan for realization a hydraulic test. Keywords: hydraulic test, stop valve, pump, flange, nozzle

Электрошлаковое литье заготовок корпусов фланцевых задвижек с приплавлением патрубков

Разработан технологический процесс производства заготовок корпусов задвижек способом электрошлакового лиття с приплавлением заранее изготовленных патрубков с фланцами. Такие задвижки широко используются при добиче нефти и газа фонтанным способом под давлением до 70 МПа. Новый технологический процесс обеспечивает получение высококачественных заготовок корпусов задвижек из среднеуглеродистых легированных сталей. Механические свойства металла всех частей заготовок превосходят требования стандарта к поковкам из таких сталей. Освоено серийное производство трех типоразмеров заготовок корпусов с рабочим каналом 50, 65 и 80 мм.Technological process of production of billets of stop valve bodies using the method of electroslag casting with a melting-on of earlier manufactured pipe branches with flanges has been developed. These s are widely used in production of oil and gas by Christmas-tree method under pressure of up to 70 MPa. The new technological process provides the producing of high-quality billets of stop valve bodies of medium-carbon alloyed steels. Mechanical properties of metal of all parts of billets are superior to those required by standard to forgings of these steels. The serial production of three types and sizes of billets of bodies with a working channel of 50, 65 and 80 mm is implemented

Atomization of liquid fuels. Part II

This report describes the design and operation of a nozzle to inject fuel into an engine. The design of the nozzle is open, without any compulsory or automatic stop-valve. The fuel injection is regulated simply by the pressure and the adjustment of the fuel pump

Плазменно-порошковая наплавка износо- и коррозионностойких сплавов в арматуростроении

Приведены результаты исследований сплавов, применяемых в арматуростроении для наплавки деталей затвора. Рассмотрены некоторые особенности плазменно-порошковой наплавки. Показано, что наилучшая работоспособность уплотнительных поверхностей достигается при использовании плазменно-порошковой наплавки.Results of investigation of alloys used in valve manufacturing for cladding of stop valve components are given. Peculiarities of plasma-powder cladding are considered. It is shown that plasma-powder cladding provides the best performance of seal surfaces

Электрошлаковое литье заготовок корпусов задвижек, работающих при высоком давлении

Рассмотрены различные способы изготовления корпусов задвижек, работающих при высоком давлении. Разработаны технологический процесс и оборудование, освоено серийное производство заготовок корпусов задвижек с фланцами на концах патрубков способом электрошлакового литья. Показано, что литые электрошлаковые корпуса по своим механическим свойствам не уступают кованым.Different methods of manufacture of bodied of stop valves operating at high pressure are studied. Technological process and equipment were developed, the serial production of stop valve bodies with flanges at the ends of branch pipes using the method of electroslag casting was mastered. It is shown that the cast electroslag bodies are not inferior to forged bodies by their mechanical properties