阅读说明：本技术 一种核电站的一回路抽真空系统及方法 (Primary loop vacuumizing system and method of nuclear power station ) 是由 闵济东 宋林 杜鹏程 费冬冬 李京 安峰 祝飞 郑嘉榕 王全亚 王再根 罗端 于 2020-12-16 设计创作，主要内容包括：本发明属于核电厂系统技术领域,具体涉及一种核电站的一回路抽真空系统及方法。本一回路抽真空运行前,在稳压器上封头安装临时人孔盖板,再通过真空喷射器将一回路抽至预期真空度,向一回路充水。真空喷射器由压缩空气提供动力,与一回路的气体混合后的排气进入空气净化系统。当稳压器液位达到设定液位时,破坏稳压器上部空间真空,将稳压器临时人孔更换为正式人孔盖板。随后继续充水,通过稳压器顶部排气管线排出剩余气体。该设计可以排出传统方式不易赶出的聚集在蒸汽发生器传热管顶部的空气,同时缩短了一回路充水时间,提升机组运行经济性。(The invention belongs to the technical field of nuclear power plant systems, and particularly relates to a primary circuit vacuumizing system and method of a nuclear power plant. Before the primary circuit is vacuumized, a temporary manhole cover plate is installed on an upper end socket of the voltage stabilizer, the primary circuit is pumped to an expected vacuum degree through a vacuum ejector, and water is filled into the primary circuit. The vacuum ejector is powered by compressed air, and exhaust mixed with gas in a primary loop enters the air purification system. When the liquid level of the voltage stabilizer reaches the set liquid level, the vacuum of the upper space of the voltage stabilizer is destroyed, and the temporary manhole of the voltage stabilizer is replaced by a formal manhole cover plate. Then, water filling is continued, and residual gas is discharged through an exhaust pipe at the top of the voltage stabilizer. The design can discharge air which is gathered at the top of the heat transfer pipe of the steam generator and is not easy to be expelled in the traditional mode, shorten the water filling time of a loop and improve the operation economy of a unit.)

1. A primary loop vacuumizing system of a nuclear power station is arranged in a containment and comprises a pressure vessel, a main pipeline hot section, a steam generator, a fluctuation pipe, a voltage stabilizer and a vacuum ejector;

the method is characterized in that:

the pressure vessel is connected with the steam generator through a main pipeline hot section, the main pipeline hot section is connected with the pressure stabilizer through a fluctuation pipe, and the top of the pressure stabilizer is connected with a safety valve exhaust pipeline and a spraying pipeline; the other end of the safety valve exhaust pipeline is divided into two paths, one path is connected with the safety valve of the voltage stabilizer, the other path is connected with the exhaust pipeline of the voltage stabilizer, and the exhaust pipeline of the voltage stabilizer is provided with an isolation valve of the exhaust pipeline of the voltage stabilizer; the other end of the spraying pipeline is connected with a pressure stabilizer spraying valve.

2. A primary circuit evacuation system for a nuclear power plant as recited in claim 1, wherein: stabiliser manhole temporary manhole apron, stabiliser manhole temporary manhole apron connect temporary manhole exhaust pipeline.

3. A primary circuit evacuation system for a nuclear power plant as recited in claim 1, wherein: the temporary manhole air suction pipeline is connected to a vacuum ejector air suction inlet pipeline through a pipeline and then connected to the vacuum ejector through a vacuum ejector air suction inlet check valve.

4. A primary circuit evacuation system for a nuclear power plant as recited in claim 3, wherein: the temporary manhole air suction pipeline is connected with an air suction inlet pipeline of the vacuum ejector through an air suction hose.

5. A primary circuit evacuation system for a nuclear power plant as recited in claim 1, wherein: compressed air is introduced into an inlet of the vacuum ejector, and a compressed air isolating valve is arranged on an introducing pipeline; the outlet end of the vacuum ejector is used for exhausting.

6. A primary circuit evacuation system for a nuclear power plant as recited in claim 1, wherein: the upper part of the voltage stabilizer is provided with a temporary manhole cover plate of the voltage stabilizer, and the temporary manhole cover plate of the voltage stabilizer is connected with a temporary manhole exhaust pipeline; the temporary manhole air suction pipeline is connected to a vacuum ejector air suction inlet pipeline through a pipeline and then connected to the vacuum ejector through a vacuum ejector air suction inlet check valve.

7. A primary circuit vacuum pumping system of a nuclear power plant as recited in claim 6, wherein: the temporary manhole air suction pipeline is connected with the vacuum ejector air suction inlet pipeline through an air suction hose.

8. A primary circuit evacuation system for a nuclear power plant as recited in claim 1, wherein: a temporary manway cover plate of the manway of the voltage stabilizer is arranged at the upper part of the voltage stabilizer, and the temporary manway cover plate 10 of the manway of the voltage stabilizer is connected with a temporary manway exhaust pipeline;

the temporary manhole air pumping pipeline is connected to an air pumping inlet pipeline of the vacuum ejector through a pipeline and is connected to the vacuum ejector through a check valve of the air pumping inlet of the vacuum ejector;

compressed air is introduced into an inlet of the vacuum ejector, and a compressed air isolating valve is arranged on an introducing pipeline; the outlet end of the vacuum ejector is used for exhausting.

9. A primary circuit vacuumizing method of a nuclear power station is characterized by comprising the following steps: reducing the liquid level of the hot section of the main pipeline to a half-pipe liquid level, installing a manway temporary manhole cover plate and a temporary manhole air pumping pipeline on the manostat, connecting the air pumping pipeline with an air pumping inlet pipeline of the vacuum ejector by using an air pumping hose, closing a loop system, and closing an air exhaust pipeline isolation valve and a vacuum breaking valve of the manostat;

opening a driving gas isolation valve, pumping out gas in a pressure vessel, a main pipeline hot section, a steam generator, a fluctuation pipe, a voltage stabilizer and other systems and equipment connected with a loop gas space through a vacuum ejector, and enabling the vacuum degree to reach an expected value; filling water into a loop, continuously vacuumizing the loop, and suspending water filling when the water filling liquid level reaches the set liquid level of the voltage stabilizer; closing the driving gas isolation valve, stopping vacuumizing, opening the vacuum breaking valve, restoring the upper space of the set liquid level of the voltage stabilizer to atmospheric pressure, and removing the temporary manhole cover plate of the manhole of the voltage stabilizer; and after the formal cover plate is installed, opening the isolation valve of the exhaust pipeline of the voltage stabilizer, continuously filling water until residual gas is exhausted from the exhaust pipeline of the voltage stabilizer, and closing the isolation valve of the exhaust pipeline of the voltage stabilizer after the water filling and exhaust process is finished.

Technical Field

The invention belongs to the technical field of nuclear power plant systems, and particularly relates to a primary circuit vacuumizing system and method of a nuclear power plant.

Background

During the starting process of a traditional M310 pressurized water reactor nuclear power plant, static exhaust, dynamic exhaust and combined exhaust are generally needed, and the reactor coolant system is subjected to dynamic exhaust and combined exhaust in a main pump inching mode.

The vice thrust tile atress of main pump under this mode, it is higher to the main pump requirement, and it is unsatisfactory to catch up with the gas effect. The pressurized water reactor coolant system can be started by adopting a vacuum water filling mode, and air which is difficult to be expelled in the traditional mode and is gathered at the top of the inverted U-shaped heat transfer pipe of the steam generator and the top cover of the pressure vessel can be discharged by utilizing the mode, so that the possibility of cavitation of the reactor coolant pump is reduced.

In addition, the key equipment of the vacuum water filling mode is a passive vacuum ejector, the performance of the ejector depends on the pipe diameter of the air extraction pipeline to a great extent, and the pipe diameter directly restricts the vacuum-pumping time, so that the economical efficiency of operation is concerned. If can design one kind and increase evacuation pipeline pipe diameter, have a return circuit evacuation system that does not cause the influence to current design, will shorten a return circuit water filling time greatly, promote unit operation economic nature.

Disclosure of Invention

In view of the above disadvantages, the present invention provides a primary circuit vacuum pumping system and method for a nuclear power station, wherein a temporary manhole cover plate of a pressure stabilizer is additionally provided, and a large-diameter air pumping pipeline is led out from the manhole cover plate and connected with a vacuum ejector through an air pumping hose. Before the primary circuit is vacuumized, a temporary manhole cover plate is installed on a manhole of the voltage stabilizer, the primary circuit is pumped to an expected vacuum degree through a vacuum ejector, and water is filled into the primary circuit. The vacuum ejector is powered by compressed air, and exhaust mixed with gas of a primary loop enters the containment vessel. When the liquid level of the pressure stabilizer reaches the set liquid level, the vacuum of the upper space of the pressure stabilizer is destroyed, and the temporary manhole cover plate of the pressure stabilizer is replaced by the formal manhole cover plate. Then, water filling is continued, and residual gas is discharged through an exhaust pipe at the top of the voltage stabilizer. The design can discharge air which is gathered at the top of the heat transfer pipe of the steam generator and is not easy to be expelled in the traditional mode, shorten the water filling time of a loop and improve the operation economy of a unit.

The technical scheme of the invention is as follows:

a primary loop vacuumizing system of a nuclear power station is arranged in a containment and comprises a pressure vessel, a main pipeline hot section, a steam generator, a fluctuation pipe, a voltage stabilizer and a vacuum ejector;

the pressure vessel is connected with the steam generator through a main pipeline hot section, the main pipeline hot section is connected with the pressure stabilizer through a fluctuation pipe, and the top of the pressure stabilizer is connected with a safety valve exhaust pipeline and a spraying pipeline; the other end of the safety valve exhaust pipeline is divided into two paths, one path is connected with the safety valve of the voltage stabilizer, the other path is connected with the exhaust pipeline of the voltage stabilizer, and the exhaust pipeline of the voltage stabilizer is provided with an isolation valve of the exhaust pipeline of the voltage stabilizer; the other end of the spraying pipeline is connected with a pressure stabilizer spraying valve.

Stabiliser manhole temporary manhole apron, stabiliser manhole temporary manhole apron connect temporary manhole exhaust pipeline.

The temporary manhole air suction pipeline is connected to a vacuum ejector air suction inlet pipeline through a pipeline and then connected to the vacuum ejector through a vacuum ejector air suction inlet check valve.

The temporary manhole air suction pipeline is connected with an air suction inlet pipeline of the vacuum ejector through an air suction hose.

Compressed air is introduced into an inlet of the vacuum ejector, and a compressed air isolating valve is arranged on an introducing pipeline; the outlet end of the vacuum ejector is used for exhausting.

A method for vacuumizing a loop of a nuclear power station is characterized in that the liquid level of a hot section of a main pipeline is reduced to a half-pipe liquid level, a manway temporary manhole cover plate and a temporary manway air exhaust pipeline are installed on a pressure stabilizer, the air exhaust pipeline is connected with an air exhaust inlet pipeline of a vacuum ejector through an air exhaust hose, a loop system is closed, and an air exhaust pipeline isolation valve and a vacuum breaking valve of the pressure stabilizer are closed;

opening a driving gas isolation valve, pumping out gas in a pressure vessel, a main pipeline hot section, a steam generator, a fluctuation pipe, a voltage stabilizer and other systems and equipment connected with a loop gas space through a vacuum ejector, and enabling the vacuum degree to reach an expected value; filling water into a loop, continuously vacuumizing the loop, and suspending water filling when the water filling liquid level reaches the set liquid level of the voltage stabilizer; closing the driving gas isolation valve, stopping vacuumizing, opening the vacuum breaking valve, restoring the upper space of the set liquid level of the voltage stabilizer to atmospheric pressure, and removing the temporary manhole cover plate of the manhole of the voltage stabilizer; and after the formal cover plate is installed, opening the isolation valve of the exhaust pipeline of the voltage stabilizer, continuously filling water until residual gas is exhausted from the exhaust pipeline of the voltage stabilizer, and closing the isolation valve of the exhaust pipeline of the voltage stabilizer after the water filling and exhaust process is finished.

The invention has the beneficial effects that:

the invention relates to a loop vacuum pumping system of a nuclear power station, which is characterized in that a temporary manhole cover plate of a voltage stabilizer is additionally arranged, and a large-pipe-diameter air pumping pipeline is led out of the manhole cover plate and is connected with a vacuum ejector through an air pumping hose.

Before a primary circuit is vacuumized, a temporary manhole cover plate is installed on an upper end socket of the voltage stabilizer, the primary circuit is pumped to a desired vacuum degree through a vacuum ejector, and water is filled into the primary circuit.

The vacuum ejector is powered by compressed air, and exhaust mixed with gas in a primary loop enters the air purification system. When the liquid level of the voltage stabilizer reaches the set liquid level, the vacuum of the upper space of the voltage stabilizer is destroyed, and the temporary manhole of the voltage stabilizer is replaced by a formal manhole cover plate.

Then, water filling is continued, and residual gas is discharged through an exhaust pipe at the top of the voltage stabilizer. The design can discharge air which is gathered at the top of the heat transfer pipe of the steam generator and is not easy to be expelled in the traditional mode, shorten the water filling time of a loop and improve the operation economy of a unit.

Drawings

FIG. 1 is a schematic view of a primary circuit vacuum pumping system of a nuclear power plant according to the present invention;

in the figure: 1-a pressure vessel; 2-main pipeline hot section; 3-a steam generator; 4-a surge pipe; 5, a voltage stabilizer; 6-safety valve exhaust line; 7-pressurizer safety valve; 8-a spray line; 9-pressure stabilizer spray valve; 10, a manway temporary manhole cover plate of the voltage stabilizer; 11-temporary manhole gas extraction line; 12-a suction hose; 13-vacuum ejector bleed inlet line; 14-vacuum ejector bleed inlet check valve; 15-vacuum ejector; 16-compressed air isolation valve; 17-compressed air; 18-vacuum breaking the pipeline; 19-vacuum break valve; 20, exhausting; 21-setting the liquid level by a voltage stabilizer; 22-half pipe level; 23-regulator exhaust line; 24-regulator exhaust line isolation valve.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, a primary circuit vacuumizing system of a nuclear power plant is arranged in a containment and comprises a pressure vessel 1, a main pipeline hot section 2, a steam generator 3, a surge pipe 4, a voltage stabilizer 5 and a vacuum ejector 15;

the pressure vessel 1 is connected with a steam generator 3 through a main pipeline hot section 2, the main pipeline hot section 2 is connected with a pressure stabilizer 5 through a fluctuation pipe 4, and the top of the pressure stabilizer 5 is connected with a safety valve exhaust pipe 6 and a spraying pipe 8; the other end of the safety valve exhaust line 6 is divided into two paths, one path is connected with the pressure stabilizer safety valve 7, the other path is connected with the pressure stabilizer exhaust line 23, and a pressure stabilizer exhaust line isolation valve 24 is arranged on the pressure stabilizer exhaust line 23; the other end of the spraying pipeline 8 is connected with a pressure stabilizer spraying valve 9;

a manway temporary manhole cover plate 10 of the voltage stabilizer is arranged at the upper part of the voltage stabilizer 5, and the manway temporary manhole cover plate 10 of the voltage stabilizer is connected with a temporary manhole exhaust pipeline 11;

the temporary manhole air suction pipeline 11 is connected to a vacuum ejector air suction inlet pipeline 13 through a pipeline and is connected to a vacuum ejector 15 through a vacuum ejector air suction inlet check valve 14;

compressed air 17 is introduced into an inlet of the vacuum ejector 15, and a compressed air isolating valve 16 is arranged on an introducing pipeline;

the outlet end of the vacuum ejector 15 is exhaust 20.

The temporary manhole air suction pipeline 11 is connected with an air suction inlet pipeline 13 of the vacuum ejector through an air suction hose 12;

on the basis of an original nuclear power unit loop system and equipment, a manway temporary manhole cover plate 10 of a voltage stabilizer, a temporary manhole air exhaust pipeline 11, an air exhaust hose 12, a driving air source required for vacuumizing, an ejector, pipelines and valves are additionally arranged.

Before a loop vacuum water filling, the liquid level of the main pipeline hot section 2 is reduced to a half-pipe liquid level 22, a manostat manhole temporary manhole cover plate 10 and a temporary manhole air pumping pipeline 11 are installed on a manostat 5, the air pumping pipeline 11 and a vacuum ejector air pumping inlet pipeline 13 are connected through an air pumping hose 12, a loop system is closed, and a manostat exhaust pipeline isolation valve 24 and a vacuum destruction valve 19 are closed.

The driving gas isolation valve 16 is opened, and the gas in the pressure vessel 1, the main pipeline hot section 2, the steam generator 3, the surge pipe 4, the pressure stabilizer 5 and other systems and equipment connected with a loop gas space is pumped out through the vacuum ejector 15, and the vacuum degree reaches a desired value. And filling water into a primary circuit, continuously vacuumizing, and suspending filling water when the water filling liquid level reaches the set liquid level 21 of the voltage stabilizer. And closing the driving gas isolation valve 16, stopping vacuumizing, opening the vacuum breaking valve 18, restoring the upper space of the set liquid level 21 of the voltage stabilizer to atmospheric pressure, and removing the temporary manhole cover plate 10 of the manhole of the voltage stabilizer. After the formal cover plate is installed, the isolation valve 24 of the exhaust pipeline of the voltage stabilizer is opened, water filling is continued until residual gas is exhausted from the exhaust pipeline 23 of the voltage stabilizer, and the isolation valve 24 of the exhaust pipeline of the voltage stabilizer is closed after the water filling and exhaust process is finished.

In the process, the temporary manhole cover plate of the pressure stabilizer is additionally arranged, the large-pipe-diameter air pumping pipeline is led out from the manhole cover plate and is connected with the vacuum ejector through the air pumping hose, so that the operation of vacuum water filling of a loop is realized, air which is difficult to expel in the traditional mode and is gathered at the top of a heat transfer pipe of the steam generator can be discharged, the main pump is prevented from being used for system dynamic exhaust and linkage exhaust, the possibility of abrasion of the main pump on a low-pressure platform auxiliary thrust tile is effectively avoided, and the safety of a unit is improved; meanwhile, the water filling time of a primary loop is greatly shortened, and the running economy of the unit is improved.

In the drawings of the disclosed embodiments of the invention, only methods related to the disclosed embodiments are referred to, other methods can refer to common design, and the same embodiment and different embodiments of the invention can be combined with each other without conflict;

the above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that are within the spirit and principle of the present invention are intended to be included in the scope of the present invention.