О характеристиках ступени осевой турбины
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Дата
2018
ORCID
DOI
10.20998/2078-774X.2018.12.14
Науковий ступінь
Рівень дисертації
Шифр та назва спеціальності
Рада захисту
Установа захисту
Науковий керівник
Члени комітету
Видавець
НТУ "ХПИ"
Анотація
Для осевых степеней паровых турбин в одномерной постановке на основе анализа полных уравнений зависимостей КПД и степени реактивности рассмотрены режимы работы в особых точках – при неподвижном роторе, максимальном КПД, холостом ходу, вентиляционных режимах. Получены значения параметров ступеней на этих режимах, как для идеальной, так и реальной рабочей среды. Выявлены особенности выбора наиболее эффективных ступеней проточной части турбин при использовании их для покрытия переменной части годовых графиков электрических нагрузок энергосистем.
Today the energy consumption structure requires using the turbine units of thermal power plants of a high power to regulate the energy system frequency and power that drop by 35 to 40 % of the rated load during the night time or stop. Nevertheless, turbine stages operate in a wide range of the mode variation ranging from those that exceed the nominal mode to pure ventilation modes. In these modes the useful mechanical energy is not only produced but it is also consumed. A stage operation quality criterion is the amount of produced energy according to the annual curve of electrical load of the turbine. To design the stages for the flow section we used one-dimensional models based on the use of ideal and real actuating media taking into consideration the branched energy loss record structure. The purpose of this research was to define the characteristics of axial stages during their operation in a wide range of modes, i.e. from the turbine rotor jerk through the modes of maximum energy efficiency and idle running to the pure ventilation mode at a zero actuating medium flow rate through the cascade. The use of complete one-dimensional equations for the cascade efficiency factor and the degree of reaction that define their geometric relations (angles α1 and β2), the eigenvalue U/C0, energy loss coefficients for guiding (ϕ) and working (ψ) cascades allows us to analyze the operation of cascades of a unit height and obtain efficiency factor relationships at the stage rim for a different degree of reaction when the eigenvalue U/C0 varies in the operation mode from U = 0 to the idle running and the Cz/U value is determined for the stage power consumption range. It was shown that a maximum efficiency factor of the stage has a different level at different sinβ2/sinα1 ratios even when the ideal actuating medium is used and it is reached at different U/C0 values and its highest value can be obtained only at α1 = β2 and the degree of reaction ρ = 0. The relationships for the determination of the efficiency factor and the eigenvalue corresponding to ηu max for ideal and real actuating media were obtained. A universal relationship of a change in the efficiency factor as a function of the eigenvalue U/C0 was obtained taking into account energy losses. The source power required for the stage operation in the modes ranging from the idle running to pure ventilation mode was estimated and the relationship for the estimation of the coefficient of ventilation power was obtained. It was established that the idle running mode onsets when the heat difference is decreased 4.7 times in comparison with the heat difference in the mode of maximum efficiency factor, independently of the degree of reaction.
Today the energy consumption structure requires using the turbine units of thermal power plants of a high power to regulate the energy system frequency and power that drop by 35 to 40 % of the rated load during the night time or stop. Nevertheless, turbine stages operate in a wide range of the mode variation ranging from those that exceed the nominal mode to pure ventilation modes. In these modes the useful mechanical energy is not only produced but it is also consumed. A stage operation quality criterion is the amount of produced energy according to the annual curve of electrical load of the turbine. To design the stages for the flow section we used one-dimensional models based on the use of ideal and real actuating media taking into consideration the branched energy loss record structure. The purpose of this research was to define the characteristics of axial stages during their operation in a wide range of modes, i.e. from the turbine rotor jerk through the modes of maximum energy efficiency and idle running to the pure ventilation mode at a zero actuating medium flow rate through the cascade. The use of complete one-dimensional equations for the cascade efficiency factor and the degree of reaction that define their geometric relations (angles α1 and β2), the eigenvalue U/C0, energy loss coefficients for guiding (ϕ) and working (ψ) cascades allows us to analyze the operation of cascades of a unit height and obtain efficiency factor relationships at the stage rim for a different degree of reaction when the eigenvalue U/C0 varies in the operation mode from U = 0 to the idle running and the Cz/U value is determined for the stage power consumption range. It was shown that a maximum efficiency factor of the stage has a different level at different sinβ2/sinα1 ratios even when the ideal actuating medium is used and it is reached at different U/C0 values and its highest value can be obtained only at α1 = β2 and the degree of reaction ρ = 0. The relationships for the determination of the efficiency factor and the eigenvalue corresponding to ηu max for ideal and real actuating media were obtained. A universal relationship of a change in the efficiency factor as a function of the eigenvalue U/C0 was obtained taking into account energy losses. The source power required for the stage operation in the modes ranging from the idle running to pure ventilation mode was estimated and the relationship for the estimation of the coefficient of ventilation power was obtained. It was established that the idle running mode onsets when the heat difference is decreased 4.7 times in comparison with the heat difference in the mode of maximum efficiency factor, independently of the degree of reaction.
Опис
Ключові слова
осевая ступень, режим работы, КПД, геометрия ступени, turbine, axial stage, operation mode, stage efficiency factor, stage geometry
Бібліографічний опис
Слабченко О. Н. О характеристиках ступени осевой турбины / О. Н. Слабченко, В. Н. Голощапов // Вісник Нац. техн. ун-ту "ХПІ" : зб. наук. пр. Сер. : Енергетичні та теплотехнічні процеси й устаткування = Bulletin of the National Technical University "KhPI" : coll. sci. papers. Ser. : Power and Heat Engineering Processes and Equipment. – Харків : НТУ "ХПІ", 2018. – № 12 (1288). – С. 75-82.