CN106024076A - Device for reducing risk of pressure relief tank compartment of nuclear power plant - Google Patents

Abstract

The invention relates to a device for reducing the risk of a pressure relief tank compartment in a nuclear power plant, which comprises an exhaust pipe (2) connected to a pressure relief tank burst valve (7) through a connecting pipe (12), the exhaust The pipe (2) extends to the upper space in the reactor containment, and the exhaust port of the exhaust pipe (2) is located in the upper space of the reactor containment and away from the wall of the containment. The device provided by the invention has simple structure, low cost, and is easy to install and maintain, and the device can guide the water vapor and hydrogen discharged from the pressure relief tank to the large space of the containment, avoiding the accumulation of hydrogen in the compartment of the pressure relief tank, preventing Containment failure due to localized hydrogen explosion.

Description

A device for reducing the risk of a pressure relief tank compartment in a nuclear power plant

technical field

The invention belongs to the technical field of nuclear power plant safety system configuration, and in particular relates to a device for reducing the risk of a pressure relief box compartment of a nuclear power plant.

Background technique

The pressure relief box is a device used by nuclear power plants to collect the water vapor discharged from the safety valve of the primary circuit. As shown in Figure 1, the pressure relief box 6 is usually located in the pressure relief box compartment 5 in the middle and lower part of the containment. A pressure relief pipeline 10 is connected, and the pressure relief pipeline 10 is connected with a pressure stabilizer 8 through a safety valve 9. In addition, the top of the pressure relief box 6 is also connected with a pressure relief box burst valve 7 (see FIG. 3 ). Under the design basis accident, when a transient or a small breach accident occurs in the primary circuit, the pressure of the primary circuit rises and exceeds the opening pressure of the safety valve 9 on the voltage stabilizer 8, and the safety valve 9 automatically opens, so that the cooling water of the primary circuit It is discharged to the pressure relief tank 6 through the pressure relief line 10. When a serious accident occurs in a nuclear power plant, in order to avoid the failure of the pressure vessel in the primary circuit under high pressure, the pressure relief of the primary circuit is usually performed through the safety valve of the regulator or the quick pressure relief valve. During this process, the coolant in the primary circuit is discharged to the pressure relief Box 6. The pressure relief box 6 can keep a certain amount of water and water vapor in the pressure relief box 6 to prevent the radioactive primary circuit cooling water from entering the containment.

However, when the internal pressure of the pressure relief box 6 is too high, the burst valve 7 on the top of the pressure relief box will be automatically opened to discharge the primary circuit coolant into the containment. During a serious accident, due to the zirconium water reaction between the overheated zirconium cladding and water vapor, a large amount of hydrogen gas will be generated. The tank blast valve 7 enters the pressure relief tank compartment 5 where the pressure relief tank 6 is located. Since the pressure relief box compartment 5 is located in the middle and lower part of the containment vessel, the air circulation is poor, which will lead to a high hydrogen concentration in the pressure relief box compartment 5, and local hydrogen combustion or even explosion may occur, thereby threatening the integrity of the containment vessel. , resulting in the release of large amounts of radioactive material to the environment.

Contents of the invention

In view of the defects existing in the prior art, the object of the present invention is to provide a device for reducing the risk of hydrogen combustion and explosion in the pressure relief box compartment of a nuclear power plant. The device has a simple structure, low cost, and is easy to install and maintain. The water vapor and hydrogen gas discharged from the pressure tank are guided to the large space of the containment vessel, so as to avoid the accumulation of hydrogen gas in the compartment of the decompression tank and prevent the failure of the containment vessel caused by local hydrogen explosion.

In order to achieve the above purpose, the technical solution adopted by the present invention is: a device for reducing the risk of the pressure relief box compartment of a nuclear power plant, wherein the pressure relief box compartment for placing the pressure relief box is located in the reactor containment of the nuclear power plant In the middle and lower part of the pressure relief box, a pressure relief pipeline is connected to the pressure relief box, and the pressure relief pipeline is connected to the voltage stabilizer through a safety valve. The top of the pressure relief box is also connected to a burst valve of the pressure relief box. The device for the risk of the pressure relief box compartment of the plant includes an exhaust pipe connected to the top of the burst valve of the pressure relief box through a connecting pipe, the exhaust pipe extends to the upper space in the reactor containment, and the exhaust pipe of the exhaust pipe The mouth is located in the upper space of the reactor containment vessel and away from the wall of the containment vessel.

Further, the lower part of the connecting pipe is connected with the blasting valve, and the upper part of the connecting pipe is connected with the exhaust pipe through the connecting flange.

Further, the exhaust port of the exhaust duct is provided with a cover plate.

Further, the exhaust pipe is fixed on the structural wall inside the containment shell through several pipe support components.

The device provided by the present invention for reducing the risk of the compartment of the pressure relief tank in a nuclear power plant can eliminate the risk of partial hydrogen explosion caused by the accumulation of hydrogen in the compartment of the pressure relief tank, and the device has a simple structure, low cost, and is convenient for installation and maintenance. It can be applied to newly designed nuclear power plants, and can also be used for technical transformation of existing nuclear power plants, thereby improving the safety of nuclear power plants.

Description of drawings

Fig. 1 is a kind of structural schematic diagram of the device for reducing the risk of nuclear power plant pressure relief box compartment provided by the present invention;

Fig. 2 is a schematic diagram of the connection of the exhaust pipe, the connecting pipe and the blasting valve of the pressure relief box in Fig. 1;

Fig. 3 is a schematic diagram of the connection between the blast valve of the existing pressure relief box and the pressure relief box.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, the pressure relief box 6 involved in the present invention is arranged in the pressure relief box compartment 5 in the reactor containment, the pressure relief box 6 is connected with a pressure relief pipeline 10, and the pressure relief pipeline 10 passes through the safety valve 9 and The voltage stabilizer 8 is connected, and the top of the pressure relief box 6 is also connected with a burst valve 7 of the pressure relief box.

A device for reducing the risk of the pressure relief tank compartment of a nuclear power plant provided by the present invention includes an exhaust pipe 2 connected to the explosion valve 7 of the pressure relief box through a connecting pipe 12, and the exhaust pipe 2 extends into the reactor containment The upper space of the exhaust pipe 2 is located in the upper space of the reactor containment and away from the wall of the containment.

In the present invention, the lower part of the connecting pipe 12 is connected with the burst valve 7 of the pressure relief box. The upper part of the connecting pipe 12 is connected to the exhaust pipe 2 through the connecting flange 1, which is convenient for maintenance.

In addition, a cover plate 3 may be provided on the exhaust port of the exhaust pipe 2 to prevent spray water and foreign matters from entering the exhaust pipe 2 .

Preferably, the exhaust pipeline 2 in the present invention can be fixed on the structural wall 11 inside the containment by several pipeline support assemblies 4 to prevent pipeline displacement caused by the injection of the burst valve 7 of the pressure relief box.

Under normal operation of the nuclear power plant, the cover plate 3 at the outlet end of the exhaust pipe 2 is closed. Under accident conditions, when the burst valve 7 of the pressure relief box is opened, a large amount of water vapor and hydrogen enter the exhaust pipe 2 through the burst valve 7 of the pressure relief box. The steam and hydrogen are discharged to the large space above the containment, so as to avoid the accumulation of hydrogen in the compartment 5 of the pressure relief box, and prevent the failure of the containment caused by the partial hydrogen explosion.

The structures described in the present invention are not limited to the examples described in the specific implementation manners. Those skilled in the art can obtain other implementation manners according to the technical solutions of the present invention, which also belong to the technical innovation scope of the present invention.

Claims (4)

1., for reducing a device for nuclear power plant's release case compartment risk, wherein, it is used for placing release Release case compartment (5) of case (6) is located at the middle and lower part of nuclear power plant's containment vessel, described release case (6) upper connection has pressure relief pipeline (10), and pressure relief pipeline (10) passes through relief valve (9) and manostat (8) being connected, described release case (6) top is also equipped with release case explosive valve (7), it is characterised in that Described device includes the discharge duct being connected by connecting tube (12) with release case explosive valve (7) top (2), described discharge duct (2) extends to the upper space in containment vessel, and described aerofluxus The air vent of pipeline (2) is positioned at containment vessel upper space and away from containment wall.

A kind of device for reducing nuclear power plant's release case compartment risk the most according to claim 1, It is characterized in that, connecting tube (12) bottom is connected with release case explosive valve (7), in connecting tube (12) Portion is connected with discharge duct (2) by adpting flange (1).

A kind of dress for reducing nuclear power plant's release case compartment risk the most according to claim 1 and 2 Put, it is characterised in that the air vent of described discharge duct (2) is provided with cover plate (3).

A kind of device for reducing nuclear power plant's release case compartment risk the most according to claim 1, It is characterized in that, discharge duct (2) is fixed in containment by some pipeline support assemblies (4) On structure wall (11).