SU966392A1

SU966392A1 - System for automatic controlling of drainage out of steam duct

Info

Publication number: SU966392A1
Application number: SU813268186A
Authority: SU
Inventors: Александр Шаулович Лейзерович; Владимир Борисович Кириллов
Priority date: 1981-03-31
Filing date: 1981-03-31
Publication date: 1982-10-15

Description

Изобретение относится к теплоэнергетике, к режимам эксплуатации влажнопаровых турбоустановок, автоматизации управления ими, в частности, управления арматурой на линиях отвода дренажа из паропровода... ⁵ The invention relates to a power system, to operating modes of wet-steam turbine units, automation of their control, in particular, control of valves on drainage lines from a steam pipe ... ⁵

Для предотвращения попадания в турбину конденсата пара из пароподводящих паропроводов осуществляется их дренирование с удалением конденсата ¹⁰в специальные дренажные баки или конденсатор через линии отвода дренажа с установленной на них оперативной запорной арматурой. Если эта арматура оставляется открытой после завершения ¹⁵дренирования, это приводит к снижению экономичности установки из-за непроизводительных утечек рабочего пара. На остановленной турбине, находящейся под вакуумом, через открытую дренажную арматуру может подсасываться воздух, расхолаживая турбину и паропрово. ды. Наоборот, несвоевременное закры2 тие дренажей создает опасность скопления конденсата и заброса его в турбину с возможными аварийными последствиями .To prevent steam condensate from entering the steam supply pipelines entering the turbine, they are drained with the removal of condensate ¹⁰ into special drainage tanks or a condenser through drainage lines with operational shutoff valves installed on them. If this valve remains open after completion of ¹⁵ drainage, this leads to a decrease in the efficiency of the installation due to unproductive leaks of working steam. On a stopped turbine, which is under vacuum, air can be sucked in through an open drainage fitting, dampening the turbine and steam line. dy. On the contrary, untimely closure of drains creates the risk of condensation accumulating and throwing it into the turbine with possible emergency consequences.

Известна система автоматического управления отводом дренажа из паропровода с использованием специализированной арматуры, так называемых автоматических конденСатоотводчиков с термодинамическим принципом действия £l J.A known system for automatically controlling drainage from a steam pipe using specialized fittings, the so-called automatic condensate traps with a thermodynamic principle of operation £ l J.

Недостатком этой системы является необходимость применения достаточно сложной специализированной арматуры.The disadvantage of this system is the need to use a fairly complex specialized fittings.

Наиболее близкой по технической сущности и достигаемому эффекту к предлагаемой является система автоматического управления отводом дренажа из паропровода, содержащая датчик температуры металла паропровода, установленный в зоне отвода дренажа и подключенный к блоку сравнения, соединенному с приводом запорной арматуры на линии отвода дренажа. Эта система с.одерThe closest in technical essence and the achieved effect to the proposed one is the automatic control system for drainage drainage from the steam pipe, containing a temperature sensor for the metal of the steam pipe installed in the drainage area and connected to the comparison unit connected to the drive of the stop valves on the drainage line. This s.oder system

966392 4 жит также датчик давления пара в паропроводе. и нелинейный преобразователь сигнала от этого датчика,,также подключенный к блоку сравнения. Сигнал на выходе нелинейного преобразователя $ соответствует температуре насыщения пара. При снижении измеряемой температуры металла до уровня температуры насыщения блок сравнения включает привод запорной арматуры, открывая, отвод W дренажа. Повышение измеряемой температуры металла над температурой насыщения с заданным допуском свидетельствует о завершении дренирования, при этом блок сравнения воздействует на привод 5 запорной арматуры в сторону закрытия^!966392 4 there is also a steam pressure sensor in the steam line. and a non-linear signal converter from this sensor, also connected to the comparison unit. The signal at the output of the nonlinear converter $ corresponds to the vapor saturation temperature. When the measured metal temperature decreases to the level of saturation temperature, the comparison unit includes a shut-off valve actuator, opening, drainage outlet W. The increase in the measured metal temperature above the saturation temperature with a given tolerance indicates the completion of drainage, while the comparison unit acts on the actuator 5 of the stop valve in the direction of closing ^!

Недостатком этой системы является невозможность ее применения для влажнопаровых установок, где температура металла паропровода при прохождении ₂₀через него насыщенного или влажного пара, независимо от наличия или отсутствия скоплений конденсата, всегда близка к температуре насыщения, которую имеет и пар, и конденсат. Вместе ₂₅с тем, именно для влажнопаровых Турбоустановок задача надежного дренирования пароподводящих паропроводов особенно важна..The disadvantage of this system is the impossibility of its application for wet-steam installations, where the temperature of the steam line metal when ₂₀ saturated or wet steam passes through it, regardless of the presence or absence of condensate accumulations, is always close to the saturation temperature that both steam and condensate have. At the same time, ₂₅ , precisely for humid-steam turbine units, the task of reliable drainage of steam-supplying steam pipelines is especially important ..

Цель изобретения - повышение надежности дренирования путем увеличения достоверности определения наличия конденсата в паропроводе, преимущественно влажного пара.The purpose of the invention is to increase the reliability of drainage by increasing the reliability of determining the presence of condensate in the steam pipe, mainly wet steam.

• Эта цель достигается Тем, что система дополнительно содержит устройст- ³⁵во локального нагрева, установленное на паропроводе в зоне отвода дренажа и соединенное с блоком периодического включения, связанным через блок запаздывания с блоком сравнения. ⁴⁰ • This object is achieved in that the system further comprises ustroyst- ³⁵ during local heating, installed on the steam line in the area of the drainage outlet and connected to the unit intermittent turning connected through a delay unit with a comparison unit. ⁴⁰

Система может содержать также второе устройство локального нагрева и второй датчик температуры металла паропровода, установленные вне зоны отвода дренажа, причем второе устройст- ⁴⁵во нагрева подсоединено к блоку периодического включения, а второй датчик температуры - к блоку сравнения.The system may also comprise a second local heating device and a second steam pipe metal temperature sensor installed outside the drainage drainage zone, the second heating device ^{45 being} connected to the periodic switching unit, and the second temperature sensor to the comparison unit.

Определение наличия конденсата в паропроводе с температурой, равной ⁵⁰температуре насыщения проходящего по паропроводу пара, основано на затратах тепла на испарение части конденсата , в“результате чего температура металла после включения устройства до-55зированного локального нагрева паропровода повышается меньше, чем при отсутствии конденсата.The determination of the presence of condensate in a steam line with a temperature equal to ⁵⁰ is the saturation temperature of the steam passing through the steam line, based on the heat consumption for the evaporation of a part of the condensate, as a result of which “the temperature of the metal rises less after switching on the device for localized heating of the steam line than in the absence of condensate.

На чертеже представлена блок-схема системы.The drawing shows a block diagram of a system.

Система содержит участок паропровода 1с линией 2 отвода дренажа, на которой установлена запорная арматура (задвижка или вентиль) 3 с приводомThe system comprises a steam pipe section 1 with a drainage drain line 2, on which shutoff valves (gate valve or valve) 3 with a drive are installed

4. По паропроводу 1 течет насыщенный или влажный пар 5. Линия 2 отвода дренажа присоединена к паропроводу 1 в зоне возможного скопления конденсата4. Saturated or wet steam flows through steam line 1. 5. Drainage line 2 is connected to steam line 1 in the zone of possible condensate accumulation.

6. В этой зоне установлены датчик 7 температуры металла паропровода и устройство 8 локального нагрева паропровода, например электрический нагреватель фиксированной мощности. В том же сечении паропровода вне зону отвода конденсата - сверху паропровода также установлен второй датчик 9 температуры металла и второе устройство 10 нагрева, идентичное первому устройству6. A temperature sensor 7 for the metal of the steam line and a device 8 for local heating of the steam line, for example, an electric heater of fixed power, are installed in this zone. In the same section of the steam pipe outside the condensate drainage zone, a second metal temperature sensor 9 and a second heating device 10 identical to the first device are also installed on top of the steam pipe

8. Устройства 8 и 10 локального нагрева подключены к источнику- 11 питания через прерыватель 12, соединенный с блоком 13 периодического включения нагревателей . Датчики 7 и 9 температуры подключены к блоку 14 сравнения. Блок 14 сравнения периодически включается в работу с запаздыванием во времени относительно включения устройств 8 и 10 локального нагрева, реализуемым блоком 15. Блок 14 сравнения соединен :с приводом 4 арматуры 3 и, воздействуя на него, открывает или закрывает отвод дренажа по линии 2.8. Devices 8 and 10 of local heating are connected to a power source 11 through a chopper 12 connected to a block 13 for periodically turning on the heaters. The temperature sensors 7 and 9 are connected to the comparison unit 14. Block 14 comparison is periodically included in the work with time delay relative to the inclusion of devices 8 and 10 of local heating, implemented by block 15. Block 14 comparison is connected: to the actuator 4 of the valve 3 and, acting on it, opens or closes the drainage drain along line 2.

Система работает следующим образом.The system operates as follows.

Блок 13, воздействуя на прерыватель 12, периодически включает устройства 8 и 10 локальногонагрева на определенный отрезок времени. В результате работы нагревателей температура металла паропровода, измеряемая датчиками 7 и 9, повышается. При этом, если в зоне отвода имеется скопление конденсата 6 влажного или перегретого параBlock 13, acting on the chopper 12, periodically turns on the device 8 and 10 local heating for a certain period of time. As a result of the operation of the heaters, the temperature of the steam pipe metal, measured by sensors 7 and 9, rises. Moreover, if there is an accumulation of condensate 6 of wet or superheated steam in the discharge zone

5, протекающего через паропровод 1, часть энергии устройства 8 уходит на частичное испарение конденсата 6. Поэтому температура металла, измеряемая датчиком 7, через заданное блоком 15 запаздывания время после включения устройств 8 и 10 локального нагрева ниже температуры, измеряемой датчиком 9· Сигнал рассогласования на выходе блока 14 сравнения, к входам которого подключены датчики 7 и 9, воздействуя на привод 4, открывает арматуру 3. После завершения дренирования паропровода 1 - удаления конденсата при очередном включении устройств 85, flowing through the steam line 1, part of the energy of the device 8 is spent on the partial evaporation of the condensate 6. Therefore, the metal temperature measured by the sensor 7, after the time set by the delay unit 15 after turning on the local heating devices 8 and 10, is lower than the temperature measured by the sensor 9 · Mismatch signal for the output of the comparison unit 14, to the inputs of which the sensors 7 and 9 are connected, acting on the actuator 4, opens the valve 3. After the drainage of the steam pipe 1 is completed, condensate is removed the next time the devices 8 are turned on

966392 6 и 10 локального нагрева, температуры металла, измеряемые датчиками 7 и 9, будут отличаться между собой на величину, меньшую заданного допуска. Отсутствие сигнала рассогласования на 5 выходе блока 14 приводит к воздействию на привод 4 арматуры 3 в сторону ее закрытия. Повторная команда на открытие арматуры 3 поступает только после повторного накопления конденсата *0 6, что приводит снова к появлению сиг * нала рассогласования на выходе блока сравнения.966392 6 and 10 of local heating, metal temperatures measured by sensors 7 and 9 will differ from each other by an amount less than the specified tolerance. The absence of a mismatch signal at the 5th output of block 14 leads to the impact on the actuator 4 of the valve 3 towards its closure. A second command to open the valve 3 is received only after the condensate is again accumulated * 0 6, which again leads to the appearance of a mismatch signal * at the output of the comparison unit.

Возможно заранее рассчитать или измерить изменение температуры металла 15 паропровода, измеряемой датчиком 7, после включения устройства 8 .при отсутствии скопления конденсата 6. Тогда отпадает необходимость в установке второго устройства 10 и датчика 9, а 20 на второй вход блока сравнения поступает сигнал, соответствующий заранее определенной температуре. Однако в этом случае работоспособность системы будет более ограниченной. 25It is possible to pre-calculate or measure the change in the temperature of the metal 15 of the steam line, measured by the sensor 7, after turning on the device 8. If there is no accumulation of condensate 6. Then there is no need to install the second device 10 and the sensor 9, and 20 the signal corresponding in advance is received at the second input of the comparison unit certain temperature. However, in this case, the operability of the system will be more limited. 25

Мощность устройств 8 и 10 локального нагрева, длительность и периодичность их включения, задаваемые блоком 13, временное запаздывание сопоставления температур, задаваемое блоком 15»зо а также допуск сопоставления температур металла, измеряемых датчиками 7 и 9, рассчитываются в соответствии с конструктивными характеристиками паропровода 1 и параметрами протекающего через него пара 5.The power of the local heating devices 8 and 10, the duration and frequency of their switching on, set by block 13, the time delay of the temperature comparison, set by the 15 ”block and the tolerance of the comparison of metal temperatures measured by sensors 7 and 9, are calculated in accordance with the design characteristics of steam line 1 and the parameters of the steam flowing through it 5.

Применение предлагаемой системы предполагается на паропроводах свежего пара влажнопаровых турбоустановок : атомных электростанций.The application of the proposed system is supposed to be on steam pipelines of a fresh pair of wet-steam turbine units: nuclear power plants.

Claims

The invention relates to a power system, to operating modes of wet steam turbine installations, to the automation of their control, in particular, to the control of valves on the drainage drainage lines from the steam line. To prevent steam condensate from entering the turbine steam from steam supply pipelines, they are drained and condensate is drained into special drainage tanks or a condenser through drainage drainage lines with operational shut-off valves installed on them. If these valves are left open after the drainage is completed, this results in a reduction in the economics of the installation due to unproductive leakage of the working steam. At a stopped turbine under vacuum, air can be drawn through the open drain fittings, dampening the turbine and steam lines. On the contrary, the late closing of the drains creates the danger of condensate accumulating and throwing it into the turbine with possible accidental consequences. A known system for automatically controlling drainage from the steam line using specialized fittings, so-called automatic steam traps with the thermodynamic principle of operation is p 1. The disadvantage of this system is the need to use rather complex specialized fittings. The closest to the technical essence and the achieved effect to the proposed is a system for automatic control of the drainage drainage from the steam line, which contains a temperature sensor of the metal of the steam line installed in the drainage drainage zone and connected to the comparator unit connected to the drive of the shutoff valve on the drainage drain line. This system s.oder3. 966 also a vapor pressure sensor in the vapor wire, and a non-linear signal converter from this sensor, also connected to the comparison unit. The signal at the output of the nonlinear converter corresponds to the vapor saturation temperature. When the measured temperature of the metal decreases to the saturation temperature level, the comparator unit includes a drive of the shut-off valves, opening, draining drainage. An increase in the measured temperature of the metal above the T1 temperature saturating | Not with a specified tolerance indicates the completion of drainage, while the comparator unit acts on the drive of the shut-off valves in the direction of closure. The disadvantage of this system is the impossibility of its use for wet steam installations, where the temperature of the steam pipe metal it is saturated or wet steam, regardless of the presence or absence of condensate accumulations, is always close to the saturation temperature that both steam and condensate have. However, it is for wet steam turbines that the task of reliable drainage of steam supply pipelines is especially important. The purpose of the invention is to increase the reliability of drainage by increasing the reliability of determining the presence of confiGHcSja in the steam pipe, mainly wet steam. This goal is achieved by the fact that the system further comprises a local heating device, installed on the steam line in the drainage drainage zone, and connected to a periodic switching unit connected via a delay unit to a comparison unit. The system may also contain a second local heating device and a second steam metal temperature sensor installed outside the drainage drain, the second heating device is connected to the periodic switching unit, and the second temperature sensor to the comparison unit. Determining the presence of condensate in the steam line with a temperature equal to the saturation temperature of the steam passing through the steam line is based on the heat required to evaporate a part of the condensate. As a result, the temperature of the metal increases less than the absence of condensate after the device is turned on. The drawing shows the block diagram of the system. The system contains a section of the steam line 1 with a line 2 of the drainage outlet, on which the shut-off valves (gate valve or valve) 3 with a drive are installed. Steam line 1 flows saturated or wet steam. 5- Line 2 drainage is connected to steam line 1 in the area of possible condensate 6. In this zone, a sensor is installed at the temperature of the metal of the steam line and the device 8 for local heating of the steam line, such as an electric fixed-bed heater. 8 of the same cross-section of the steam line outside the condensate drain — a second metal temperature sensor 9 and a second heating device 10, identical to the first device 8, are also installed on top of the steam pipe. The devices 8 and 10 of the local heating are connected to the 1T power supply through an interrupter 12 connected to the periodic switching unit 13 heaters. Temperature sensors 7 and 9 are connected to a comparison unit 1k. Comparison unit I is periodically turned on. The operation is delayed in time relative to the switching on of devices 8 and local heating tO realized by block T5. White T4 comparison is connected to the actuator of the valve 3 And if it acts on it, it opens or closes the drainage drain on line 2. The system works as follows. Unit 13 is exposed to the interrupter 12, periodically turns on the devices 8 and 10 local heating for a certain period of Time. As a result of the operation of the heaters, the temperature of the metal of the steam line, as measured by sensors 7 and 9, increases. In this case, if there is accumulation of condensate 6 of wet or superheated steam 5 flowing through the steam line 1 in the removal zone, part of the energy of the device 8 goes to partially evaporate the condensate 6. Therefore, the metal temperature measured by the sensor 7 after the unit specified (5 delay) switching on devices 8 and 16 of local heating below the temperature measured by sensor 9. The error signal at the output of the l4 comparison unit, to the inputs of which the sensors 7 and 9 are connected, acts on the actuator, opens the armature 3. Upon completion of the drains steam line 1 - removing condensate 6 when the local heating devices 8 and 10 are switched on next time, the metal temperatures measured by sensors 7 and 9 will differ between themselves by an amount less than the specified tolerance. Ts of the valve 3 towards its closure. The re-command to open the valve 3 comes only after re-accumulation of condensate 6, which again leads to the appearance of a mismatch signal at the output of the comparison unit H. It is possible to calculate in advance or measure the change in temperature of the metal of the steam line measured by sensor 7 after switching on the device 8. a certain temperature. However, in this case, the performance of the system will be more limited. The power of devices 8 and 10 of local heating, the duration and frequency of their switching on, set by block 13, the time lag is compared to the temperatures set by block IS. and the tolerance of the comparison of metal temperatures measured by the sensors 7 and 9 is calculated in accordance with the design characteristics of the steam line 1 and the parameters of the steam flowing through it 5. The proposed system is assumed to be fresh on the steam lines. a pair of wet steam turbine i nuclear power plants. Claim 1. A system for automatically controlling a drainage drainage from a steam line, comprising a steam line metal temperature sensor installed in a drainage drainage zone and connected to a comparator unit connected to a shut-off valve drive on a drainage drain line, which is designed to improve reliability by increasing the reliability of determining the presence of condensate in the conduit, mainly wet steam, the system additionally contains a local heating device installed on the steam line. e in the zone of diversion and drainage and connected to the periodic switching unit, connected through the delay unit with the comparison unit .., 2, The system according to claim 1, stating that it has a second local device heating and the second metal temperature sensor of the pa-: conductor installed outside the drainage drainage zone, the second heating device is connected to the periodic switching unit, and the second temperature sensor to the comparison unit. Sources of information taken into account in the examination of 1. Kirkhgof G. On some elements of automation of launch operations at thermal power plants. M ,, BTI ORGRZS, a series of Energy abroad, with. 9.

2. US patent number 197E90, class. 236-1, publ. 1980