阅读说明：本技术 低位布置给水泵汽轮机的下排汽管道疏水系统及疏水方法 (Drainage system and drainage method for lower steam exhaust pipeline of low-position-arranged water feeding pump steam turbine ) 是由 姜凯 杜洪岩 倪玖欣 柴艳琴 张瑞 于 2019-11-04 设计创作，主要内容包括：本发明公开了一种低位布置给水泵汽轮机的下排汽管道疏水系统及疏水方法,解决了低位布置给水泵的汽轮机下排汽管道的疏水难题。当疏水集箱(10)的液位较低时,关闭泵前疏水关断阀(19)和真空破坏关断阀(14),打开阀前关断阀(7)、阀后关断阀(8)和抽真空关断阀(12),乏汽排汽管道(2)的疏水利用高差自动流入疏水集箱；当疏水集箱(10)的液位较高时,关闭阀前关断阀、阀后关断阀和抽真空关断阀(12),打开真空破坏关断阀(14)、泵前疏水关断阀(19)、第一泵后疏水关断阀和第二泵后疏水关断阀,利用疏水泵(17)将疏水集箱的疏水排入到凝汽器(4)中。保证给水泵汽轮机的安全运行,进而满足机组发电量要求。(The invention discloses a drainage system and a drainage method for a lower steam exhaust pipeline of a steam turbine with a low-level arranged feed pump, which solve the drainage problem of the lower steam exhaust pipeline of the steam turbine with the low-level arranged feed pump. When the liquid level of the drainage header (10) is low, closing a drainage shutoff valve (19) in front of the pump and a vacuum breaking shutoff valve (14), opening a valve-front shutoff valve (7), a valve-rear shutoff valve (8) and a vacuumizing shutoff valve (12), and automatically allowing drainage of the exhaust steam exhaust pipeline (2) to flow into the drainage header by using height difference; when the liquid level of the drainage header (10) is high, the pre-valve shut-off valve, the post-valve shut-off valve and the vacuumizing shut-off valve (12) are closed, the vacuum breaking shut-off valve (14), the pre-pump drainage shut-off valve (19), the first post-pump drainage shut-off valve and the second post-pump drainage shut-off valve are opened, and drainage of the drainage header is drained into the condenser (4) by the drainage pump (17). The safe operation of the water supply pump steam turbine is ensured, and the requirement of the generating capacity of the unit is further met.)

1. A lower steam exhaust pipeline drainage system of a low-position arranged water feeding pump turbine comprises a water feeding pump turbine (1), a condenser (4), a drainage header (10) and a drainage pump (17), wherein a steam exhaust pipeline (2) is connected between the water feeding pump turbine (1) and the condenser (4), and a steam exhaust shut-off valve (3) is arranged on the steam exhaust pipeline (2), the system is characterized in that a front valve drainage pipeline (5) is arranged on the steam exhaust pipeline (2) in front of the steam exhaust shut-off valve (3), a rear valve drainage pipeline (6) is arranged on the steam exhaust pipeline (2) behind the steam exhaust shut-off valve (3), the other end of the front valve drainage pipeline (5) is communicated with the drainage header (9), the other end of the rear valve drainage pipeline (6) is communicated with the drainage header (9), the drainage header (9) is communicated with the drainage header (10), a front valve shut-off valve (7) is arranged on the front valve drainage pipeline (5), a valve rear shut-off valve (8) is arranged on a valve rear drain pipeline (6), a vacuumizing pipeline (11) and a vacuum destruction pipeline (13) are respectively arranged on a drain collection box (10), the other end of the vacuumizing pipeline (11) is communicated with a steam exhaust pipeline (2), a vacuumizing shut-off valve (12) is arranged on the vacuumizing pipeline (11), the other end of the vacuum destruction pipeline (13) is communicated with the atmosphere, a vacuum destruction shut-off valve (14) is arranged on the vacuum destruction pipeline (13), the drain collection box (10) is communicated with the input end of a drain pump (17) through a drain discharge pipeline (15), a pump front drain shut-off valve (19) is arranged on the drain discharge pipeline (15), the output end of the drain pump (17) is communicated with a condenser (4) through the pump rear drain discharge pipeline (18), and a check valve (20) are respectively arranged on the pump rear drain discharge pipeline (18), A first post-pump drain shut-off valve (21) and a second post-pump drain shut-off valve (22); a liquid level meter (16) is arranged on the drainage header (10).

2. The drain system of the lower steam exhaust pipeline of the low-position feed pump steam turbine as claimed in claim 1, wherein a spare drain pipeline is arranged between the drain header (10) and the condenser (4), and a spare drain pump, a spare check valve, a spare pump front drain shut-off valve and a spare pump rear drain shut-off valve are arranged on the spare drain pipeline.

3. The drainage method of the drain pipe drainage system of the low-position arrangement feed water pump steam turbine is characterized in that when the liquid level of the drain header (10) is low, the drain shut-off valve (19) before the pump and the vacuum breaking shut-off valve (14) are closed, the drain shut-off valve (7) before the valve, the drain shut-off valve (8) after the valve and the vacuum pumping shut-off valve (12) are opened, and the drainage of the steam exhaust pipeline (2) automatically flows into the drain header (10) by using the height difference; when the liquid level of the drainage header (10) is high, the pre-valve shut-off valve (7), the post-valve shut-off valve (8) and the vacuumizing shut-off valve (12) are closed, the vacuum breaking shut-off valve (14), the pre-pump drainage shut-off valve (19), the first-pump post-drainage shut-off valve (21) and the second-pump post-drainage shut-off valve (22) are opened, and drainage of the drainage header (10) is drained into the condenser (4) by the drainage pump (17).

Technical Field

The invention relates to a drainage system of a lower steam exhaust pipeline of a low-position arranged water feeding pump steam turbine, which solves the drainage problem of the steam exhaust pipeline of the steam turbine and simultaneously does not influence the operation of the water feeding pump steam turbine and a drainage method.

Background

In the current thermal power plant, a water feed pump set driven by a steam turbine is improved or newly built so as to achieve the purposes of reducing the plant power consumption rate and the power supply coal consumption and improving the economy of a generator set; when the water supply pump steam turbine is started, the steam discharge and drainage amount is large, and when the water supply pump steam turbine normally operates, part of water spray is taken away by steam discharge due to the water spray of the low pressure cylinder, so that water accumulation of a steam discharge pipeline is easily caused; in order to ensure the normal operation of the unit, drainage must be discharged in time; in part of transformation projects, limited by conditions on site, a water supply pump turbine needs to be arranged at a low position, and lower steam is adopted to be connected to a condenser, at the moment, the drainage point of a steam exhaust pipeline is far lower than the normal condensate liquid level of the condenser, and drainage of the steam exhaust pipeline cannot normally flow back to the condenser under the influence of liquid level difference and pressure; if a method of additionally arranging a drainage pump is adopted, the blades of the drainage pump set can generate cavitation erosion due to the fact that the steam exhaust pipeline runs in vacuum, and the drainage pump set cannot run for a long time; if the drainage is directly discharged to the trench, the drainage pressure is negative pressure, so that the drainage cannot be discharged to the environment of atmospheric pressure. Therefore, drainage of the steam turbine lower exhaust pipe of the low-level water supply pump becomes a difficult problem in field operation.

Disclosure of Invention

The invention provides a drainage system and a drainage method for a lower steam exhaust pipeline of a steam turbine with a low-level arranged feed pump, which solve the drainage problem of the lower steam exhaust pipeline of the steam turbine with the low-level arranged feed pump.

The invention solves the technical problems by the following technical scheme:

a drainage system of a lower steam exhaust pipeline of a low-position arranged water feeding pump turbine comprises the water feeding pump turbine, a condenser, a drainage header and a drainage pump, wherein a steam exhaust pipeline is connected between the water feeding pump turbine and the condenser, a steam exhaust shutoff valve is arranged on the steam exhaust pipeline, a front drainage pipeline is arranged on the steam exhaust pipeline in front of the steam exhaust shutoff valve, a rear drainage pipeline is arranged on the steam exhaust pipeline behind the steam exhaust shutoff valve, the other end of the front drainage pipeline is communicated with a drainage header, the other end of the rear drainage pipeline is communicated with the drainage header, the drainage header is communicated with the drainage header, a front shutoff valve is arranged on the front drainage pipeline, a rear shutoff valve is arranged on the rear drainage pipeline, a vacuum pumping pipeline and a vacuum breaking pipeline are respectively arranged on the drainage header, the other end of the vacuum pumping pipeline is communicated with the steam exhaust pipeline, the vacuum-pumping pipeline is provided with a vacuum-pumping shutoff valve, the other end of the vacuum-pumping pipeline is communicated with the atmosphere, the vacuum-pumping pipeline is provided with a vacuum-pumping shutoff valve, the drain collection box is communicated with the input end of a drain pump through a drain discharge pipeline, the drain discharge pipeline is provided with a pre-pump drain shutoff valve, the output end of the drain pump is communicated with a condenser through a post-pump drain discharge pipeline, and the post-pump drain discharge pipeline is respectively provided with a check valve, a first post-pump drain shutoff valve and a second post-pump drain shutoff valve; a liquid level meter is arranged on the drainage header.

A standby drainage discharge pipeline is arranged between the drainage header and the condenser, and a standby drainage pump, a standby check valve, a standby pump front drainage shutoff valve and a standby pump rear drainage shutoff valve are arranged on the standby drainage discharge pipeline.

A drainage method of a drainage system of a lower steam exhaust pipeline of a steam turbine with a low-position arranged feed pump comprises the steps of closing a drainage shutoff valve in front of the pump and a vacuum breaking shutoff valve when the liquid level of a drainage header is low, opening the drainage shutoff valve in front of the pump, the shutoff valve behind the pump and the vacuum breaking shutoff valve, and automatically flowing drainage of a steam exhaust pipeline into the drainage header by utilizing height difference; when the liquid level of the drainage header is high, the pre-valve shut-off valve, the post-valve shut-off valve and the vacuumizing shut-off valve are closed, the vacuum breaking shut-off valve, the pre-pump drainage shut-off valve, the first-pump post-drainage shut-off valve and the second-pump post-drainage shut-off valve are opened, and drainage of the drainage header is discharged into the condenser by the drainage pump.

On the basis of not influencing the operation of the water supply pump turbine, the drainage of the lower steam exhaust pipeline of the water supply pump turbine arranged at a low position can be smoothly discharged, the safe operation of the water supply pump turbine is ensured, and the requirement of the generating capacity of a unit is further met. Meanwhile, the waste of high-quality feed water is avoided by recycling the drained water, and the operation cost is reduced. The system is simple and can be flexibly adjusted according to the running state.

Drawings

Fig. 1 is a schematic structural view of the present invention.

Detailed Description

The invention is described in detail below with reference to the accompanying drawings:

a drain pipeline drainage system of a low-position arranged water feeding pump turbine comprises a water feeding pump turbine 1, a condenser 4, a drain header 10 and a drain pump 17, wherein a waste steam exhaust pipeline 2 is connected between the water feeding pump turbine 1 and the condenser 4, a waste steam shut-off valve 3 is arranged on the exhaust pipeline 2, a before-valve drain pipeline 5 is arranged on the exhaust pipeline 2 in front of the waste steam shut-off valve 3, a after-valve drain pipeline 6 is arranged on the exhaust pipeline 2 behind the waste steam shut-off valve 3, the other end of the before-valve drain pipeline 5 is communicated with the drain header 9, the other end of the after-valve drain pipeline 6 is communicated with the drain header 9, the drain header 9 is communicated with the drain header 10, a before-valve shut-off valve 7 is arranged on the before-valve drain pipeline 5, an after-valve shut-off valve 8 is arranged on the after-valve drain pipeline 6, a vacuum pumping pipeline 11 and a vacuum breaking pipeline 13 are respectively arranged on the drain header 10, the other end of the vacuumizing pipeline 11 is communicated with the steam exhaust pipeline 2, a vacuumizing shutoff valve 12 is arranged on the vacuumizing pipeline 11, the other end of the vacuum destroying pipeline 13 is communicated with the atmosphere, a vacuum destroying shutoff valve 14 is arranged on the vacuum destroying pipeline 13, the drain header 10 is communicated with the input end of a drain pump 17 through a drain discharge pipeline 15, a pre-pump drain shutoff valve 19 is arranged on the drain discharge pipeline 15, the output end of the drain pump 17 is communicated with the condenser 4 through a post-pump drain discharge pipeline 18, and a check valve 20, a first post-pump drain shutoff valve 21 and a second post-pump drain shutoff valve 22 are respectively arranged on the post-pump drain discharge pipeline 18; a liquid level gauge 16 is provided on the drain header 10.

A standby drain discharge pipeline is arranged between the drain collection box 10 and the condenser 4, and a standby drain pump, a standby check valve, a standby pump front drain shutoff valve and a standby pump rear drain shutoff valve are arranged on the standby drain discharge pipeline.

A drainage method of a drain pipeline drainage system of a low-position arranged water feeding pump steam turbine, when the liquid level of a drainage header 10 is low, a drain shut-off valve 19 in front of a pump and a vacuum breaking shut-off valve 14 are closed, a drain shut-off valve 7 in front of the pump, a drain shut-off valve 8 behind the pump and a vacuumizing shut-off valve 12 are opened, and drainage of a steam exhaust pipeline 2 automatically flows into the drainage header 10 by using height difference; when the liquid level of the drainage header 10 is high, the pre-valve shut-off valve 7, the post-valve shut-off valve 8 and the vacuumizing shut-off valve 12 are closed, the vacuum breaking shut-off valve 14, the pre-pump drainage shut-off valve 19, the first post-pump drainage shut-off valve 21 and the second post-pump drainage shut-off valve 22 are opened, and drainage of the drainage header 10 is drained into the condenser 4 by using the drainage pump 17

On the basis of not influencing the operation of the water supply pump turbine, the drainage of the lower steam exhaust pipeline of the water supply pump turbine arranged at a low position can be smoothly discharged, the safe operation of the water supply pump turbine is ensured, the requirement of the generating capacity of a unit is further met, and the problem of negative pressure drainage is solved. Meanwhile, the waste of high-quality feed water is avoided due to the recovery of the drained water, the cyclic utilization of the high-quality feed water is realized, and the operation cost is reduced; the system has simple structure, and the drainage system can be flexibly adjusted through the liquid level of the drainage header and the drainage pump; the system is low in cost, is suitable for a drainage system of a lower steam exhaust pipeline of a water feeding pump steam turbine arranged at a low position, and is particularly suitable for a drainage system of a steam exhaust pipeline of a water feeding pump steam turbine of a unit, which has large unit load, large drainage quantity and high requirement on generated energy. If the operation reliability is considered, the drainage pump and the related valves can be provided with two sets, and the drainage pump and the related valves can be reliably operated by one set.