阅读说明：本技术 一种铅铋堆沉浸式非能动余热排出系统及方法 (Immersion type passive waste heat discharging system and method for lead bismuth pile ) 是由 郭超 邓坚 严明宇 黄代顺 王啸宇 隋海明 孙伟 陈仕龙 李沛颖 于 2021-07-15 设计创作，主要内容包括：本发明属于反应堆安全系统设计领域,具体公开了一种铅铋堆沉浸式非能动余热排出系统及方法,该一种铅铋堆沉浸式非能动余热排出系统包括：反应堆容器、堆芯、蒸汽发生器、热池、冷池、独立余热排出热交换器和空气冷却器；堆芯、蒸汽发生器、热池、冷池和独立余热排出热交换器均位于反应堆容器内,空气冷却器位于反应堆容器的上方,独立余热排出热交换器的一次侧进出口与热池连接,独立余热排出热交换器的二次侧进出口通过连接管路与空气冷却器连接。本发明实现铅铋堆在事故工况下的一回路自然循环、中间回路自然循环,通过空气冷却带走堆芯余热,可靠性高,余热排出能力强,并将反应堆带至安全稳定状态。(The invention belongs to the field of design of a reactor safety system, and particularly discloses a submerged passive waste heat removal system and a submerged passive waste heat removal method for a lead bismuth reactor, wherein the submerged passive waste heat removal system for the lead bismuth reactor comprises the following components: the reactor comprises a reactor vessel, a reactor core, a steam generator, a hot pool, a cold pool, an independent waste heat discharge heat exchanger and an air cooler; the reactor core, the steam generator, the hot pool, the cold pool and the independent waste heat discharging heat exchanger are all located in the reactor container, the air cooler is located above the reactor container, a primary side inlet and outlet of the independent waste heat discharging heat exchanger is connected with the hot pool, and a secondary side inlet and outlet of the independent waste heat discharging heat exchanger is connected with the air cooler through a connecting pipeline. The invention realizes the primary loop natural circulation and the intermediate loop natural circulation of the lead bismuth reactor under the accident condition, takes away the residual heat of the reactor core through air cooling, has high reliability and strong residual heat discharge capacity, and brings the reactor to a safe and stable state.)

1. The submerged passive residual heat removal system for the lead-bismuth pile is characterized by comprising: the reactor comprises a reactor vessel (1), a reactor core (2), a steam generator (3), a hot pool (4), a cold pool (5), an independent waste heat discharge heat exchanger (6) and an air cooler (7);

the reactor core (2) and the steam generator (3) are both positioned in the reactor vessel (1), and the steam generator (3) is arranged at a higher position relative to the reactor core (2); the hot pool (4) is positioned in the upper region of the reactor core (2) and the steam generator (3), and the cold pool (5) is positioned in the lower region of the reactor core (2) and the steam generator (3); the reactor core (2) is connected with the hot pool (4) through a reactor core outlet, the steam generator (3) is connected with the hot pool (4) through a steam generator inlet, the reactor core (2) is connected with the cold pool (5) through a reactor core inlet, and the steam generator (3) is connected with the cold pool (5) through a steam generator outlet;

the independent waste heat discharge heat exchanger (6) is positioned in the reactor container (1), the independent waste heat discharge heat exchanger (6) is arranged at a higher position relative to the steam generator (3), and a primary side inlet and outlet of the independent waste heat discharge heat exchanger (6) are connected with the hot pool (4);

the air cooler (7) is positioned above the reactor container (1), and a secondary side inlet and outlet of the independent waste heat discharge heat exchanger (6) is connected with the air cooler (7) through a connecting pipeline.

2. The submerged passive residual heat removal system for the lead-bismuth pile is characterized in that the independent residual heat removal heat exchanger (6), the air cooler (7) and the connecting pipeline form an intermediate loop, and the intermediate loop is a closed loop for leading out residual heat.

3. The submerged passive residual heat removal system for the lead-bismuth pile is characterized in that the independent residual heat removal heat exchanger (6) is positioned below the free liquid level (8) of the hot pool (4).

4. The submerged passive residual heat removal system for the lead bismuth pile as claimed in claim 2, wherein an electromagnetic valve is arranged on a connecting pipeline of the intermediate circuit, and the electromagnetic valve is automatically opened under an accident condition to establish natural circulation of the intermediate circuit.

5. A waste heat removal method adopting the submerged passive waste heat removal system for the lead-bismuth pile as claimed in claim 2, which is characterized by comprising the following steps:

step 1, establishing a reactor primary loop natural circulation, and transferring reactor core waste heat from a reactor core (2) to a hot pool (4);

step 2, transferring the waste heat in the heat pool (4) to an intermediate loop through an independent waste heat discharge heat exchanger (6);

and 3, establishing stable intermediate loop natural circulation and transferring the waste heat of the reactor core to the outside air.

6. The submerged passive residual heat removal method for the lead bismuth pile according to claim 5, wherein the step 1 is specifically as follows: under the accident condition, temperature difference is established between the reactor core (2) and the independent waste heat discharging heat exchanger (6) in the primary loop to form primary loop natural circulation, and the reactor core waste heat is led out to the heat pool (4) from the reactor core (2).

7. The submerged passive residual heat removal method for the lead bismuth pile according to claim 5, wherein the step 2 is specifically as follows: under the accident condition, temperature difference is established between the independent waste heat discharging heat exchanger (6) and the air cooler (7) to form natural circulation of an intermediate loop, and waste heat in the heat pool (4) is transferred to the intermediate loop.

8. The submerged passive residual heat removal method for the lead bismuth pile according to claim 5, wherein the step 3 is specifically as follows: and opening an air door of the air cooler (7), and performing heat convection on cold air and the coolant of the intermediate loop in the air cooler (7) to ensure that the intermediate loop establishes stable natural circulation and the heat of the coolant of the intermediate loop is transferred to external air.

Technical Field

The invention belongs to the field of design of reactor safety systems, and particularly relates to a submerged passive waste heat removal system and method for a lead-bismuth reactor.

Background

When the lead bismuth reactor normally operates, the heat generated by the fission of the reactor core is taken away by the steam generator. Under the condition of accident, if the steam generator cannot be used, a reactor core waste heat discharge system is configured to lead out the reactor core waste heat, so that the reactor core is prevented from being melted and developing into serious accidents. The active waste heat removal system adopted by the traditional reactor depends on external power, once the external power loss accident such as station blackout occurs, the active waste heat removal system cannot normally derive the waste heat of the reactor core, and the reactor core is further heated and deteriorated to further develop into a serious accident under the condition of no other waste heat deriving measures. Therefore, a passive residual heat removal system needs to be designed to ensure heat removal of the reactor in an accident.

The traditional pressurized water reactor adopts a loop type design, and a passive residual heat removal system of the traditional pressurized water reactor is designed according to the characteristics of a loop. The lead bismuth reactor has unique structural design, a primary loop system adopts an integrated pool type structural design, the primary loop system is divided into a hot pool and a cold pool, a steam generator is placed in the primary loop pool, and the designs are all different from the loop type design of a pressurized water reactor. Therefore, the traditional passive residual heat removal system cannot be applied to the pool type lead-bismuth pile.

Therefore, development of a passive residual heat removal system and method suitable for a lead-bismuth reactor is urgently needed to realize normal derivation of reactor core residual heat.

Disclosure of Invention

The invention aims to provide a submerged passive residual heat removal system and method for a lead bismuth pile, which realize the natural circulation of a primary loop and the natural circulation of an intermediate loop of the lead bismuth pile under the accident condition and take away the residual heat of a reactor core through air cooling.

The technical scheme for realizing the purpose of the invention is as follows:

a submerged passive residual heat removal system for a lead bismuth pile, comprising: the reactor comprises a reactor vessel, a reactor core, a steam generator, a hot pool, a cold pool, an independent waste heat discharge heat exchanger and an air cooler;

the reactor core and the steam generator are both positioned in the reactor vessel, and the steam generator is arranged at a higher position relative to the reactor core; the hot pool is positioned in the upper region of the reactor core and the steam generator, and the cold pool is positioned in the lower region of the reactor core and the steam generator; the reactor core is connected with the hot pool through a reactor core outlet, the steam generator is connected with the hot pool through a steam generator inlet, the reactor core is connected with the cold pool through a reactor core inlet, and the steam generator is connected with the cold pool through a steam generator outlet;

the independent waste heat discharge heat exchanger is positioned in the reactor container, the independent waste heat discharge heat exchanger is arranged at a higher position relative to the steam generator, and a primary side inlet and outlet of the independent waste heat discharge heat exchanger is connected with the hot pool;

the air cooler is positioned above the reactor container, and the secondary side inlet and outlet of the independent waste heat discharge heat exchanger are connected with the air cooler through connecting pipelines.

Furthermore, the independent waste heat discharge heat exchanger, the air cooler and the connecting pipeline form an intermediate loop, and the intermediate loop is a closed loop for leading out waste heat.

Further, the independent waste heat discharge heat exchanger is positioned below the free liquid level of the hot pool.

Furthermore, an electromagnetic valve is arranged on a connecting pipeline of the intermediate circuit, and the electromagnetic valve is automatically opened under the accident condition to establish natural circulation of the intermediate circuit.

A waste heat removal method adopting a lead bismuth pile immersion type passive waste heat removal system comprises the following steps:

step 1, establishing a reactor primary loop natural circulation, and transferring reactor core waste heat from a reactor core to a hot pool;

step 2, transferring the waste heat in the hot pool to an intermediate loop through an independent waste heat discharge heat exchanger;

and 3, establishing stable intermediate loop natural circulation and transferring the waste heat of the reactor core to the outside air.

Further, the step 1 specifically comprises: under the accident condition, a temperature difference is established between the reactor core and the independent waste heat discharging heat exchanger in the primary loop to form a primary loop natural circulation, and the reactor core waste heat is led out to the heat pool from the reactor core.

Further, the step 2 specifically includes: under the accident condition, the electromagnetic valve is automatically opened, the temperature difference is established between the independent waste heat discharging heat exchanger and the air cooler, natural circulation of an intermediate loop is formed, and waste heat in the heat pool 4 is transferred to the intermediate loop.

Further, the step 3 specifically includes: and opening an air door of the air cooler, and performing heat convection on the cold air and the coolant of the intermediate loop in the air cooler to ensure that the intermediate loop establishes stable natural circulation and the heat of the coolant of the intermediate loop is transferred to the external air.

The invention has the beneficial technical effects that:

1. the immersed passive residual heat removal system for the lead-bismuth reactor provided by the invention has the advantages that the temperature difference is established between the reactor core in the primary loop of the reactor and the independent residual heat removal heat exchanger, the stable natural circulation is established in the primary loop through the cold and hot end position difference of the independent residual heat removal heat exchanger, the reactor core residual heat is transmitted to the independent residual heat removal heat exchanger from the reactor core, and then is transmitted to air by the independent residual heat removal heat exchanger, so that the reactor core residual heat is led out in an air-cooled passive mode.

2. The invention provides a lead bismuth pile immersion type passive residual heat removal system, which comprises a residual heat removal intermediate loop formed by an independent heat exchanger, an air cooler and a connecting pipeline, wherein heat is transferred to the air cooler through the independent residual heat removal heat exchanger, the air rises after being heated, and cold air is continuously sucked from an inlet by utilizing the density difference of the cold air and the hot air to form stable air cooling flow, meanwhile, the intermediate loop forms stable natural circulation, and the heat is finally discharged to the atmosphere.

3. The immersion type passive waste heat removal system for the lead bismuth stack is independent of a primary and secondary loop heat transmission system under normal working conditions, and is high in reliability and strong in waste heat removal capacity.

4. Compared with a non-immersion type passive waste heat discharge system, the immersion type waste heat discharge system is directly contacted with the heat pool, the heat exchange area with the heat pool is large, heat can be directly taken away from the heat pool efficiently and rapidly, a primary loop can be established to realize natural circulation, and waste heat of a reactor core can be taken away.

5. According to the design characteristics of the lead-bismuth reactor, the immersion type passive waste heat removal system is configured in the heat pool in the reactor container by utilizing the passive technical idea according to the design characteristics of the lead-bismuth reactor, natural circulation is established through a loop to take away the waste heat of the reactor core, and the reactor is brought to a safe and stable state.

Drawings

Fig. 1 is a schematic structural diagram of a submerged passive residual heat removal system of a lead bismuth pile provided by the invention;

in the figure: 1-a reactor vessel; 2, a reactor core; 3-a steam generator; 4-a hot tank; 5-a cold pool; 6-independent waste heat is discharged from the heat exchanger; 7-an air cooler; 8-free liquid level.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

As shown in fig. 1, the submerged passive residual heat removal system for a lead-bismuth pile provided by the invention comprises: the reactor comprises a reactor vessel 1, a reactor core 2, a steam generator 3, a hot pool 4, a cold pool 5, an independent waste heat discharge heat exchanger 6 and an air cooler 7.

The core 2 and the steam generators 3 are both located within the reactor vessel 1, and the steam generators 3 are disposed at a higher position relative to the core 2. The hot pool 4 is located in the upper region of the core 2 and the steam generators 3, and the cold pool 5 is located in the lower region of the core 2 and the steam generators 3. The reactor core 2 is connected with the hot pool 4 through the reactor core outlet, the steam generator 3 is connected with the hot pool 4 through the steam generator inlet, the reactor core 2 is connected with the cold pool 5 through the reactor core inlet, and the steam generator 3 is connected with the cold pool 5 through the steam generator outlet.

The independent waste heat discharge heat exchanger 6 is positioned in the reactor vessel 1, the independent waste heat discharge heat exchanger 6 is arranged at a higher position relative to the steam generator 3 and is positioned below the free liquid level 8 of the hot pool 4, so that the independent waste heat discharge heat exchanger 6 is completely immersed in the hot pool 4; the primary side inlet and outlet of the independent waste heat discharge heat exchanger 6 are connected with the heat pool 4.

The air cooler 7 is positioned above the reactor container 1, the secondary side inlet and outlet of the independent waste heat discharge heat exchanger 6 are connected with the air cooler 7 through a connecting pipeline, a closed loop is formed among the independent waste heat discharge heat exchanger 6, the air cooler 7 and the connecting pipeline, and the closed loop is an intermediate loop for leading out waste heat. The electromagnetic valve is arranged on a connecting pipeline of the intermediate loop and automatically opened under the accident condition, and the specific process is that under the accident condition, when the temperature of the in-reactor hot pool exceeds 600 ℃, an electromagnetic valve opening signal is triggered, and the electromagnetic valve is automatically opened. After the solenoid valve is opened, the intermediate loop establishes natural circulation to lead out the heat of the hot pool 4 in the reactor vessel 1. The coolant of the intermediate loop adopts lead bismuth, and the final heat trap is air.

The working principle of the immersion type passive waste heat removal system of the lead bismuth pile is as follows:

under the accident condition of lead bismuth reactor, normal heat transfer system became invalid, the solenoid valve was opened automatically under the accident condition, natural circulation was established to reactor one loop, reactor one loop coolant heat passed through independent heat exchanger and is given middle return circuit, middle return circuit gives the air cooler with heat transfer, rise after the air heating, utilize cold and hot air density difference, make cold air continuously inhale from the entrance, form stable air cooling flow, also make middle return circuit form stable natural circulation simultaneously, the heat is finally derived to the atmosphere.

A waste heat discharge method of a lead bismuth pile immersion type passive waste heat discharge system specifically comprises the following steps:

step 1, establishing a reactor primary loop natural circulation, and transferring reactor core waste heat from a reactor core 2 to a hot pool 4

Under the accident condition of lead bismuth reactor, when normal heat transfer system became invalid, the coolant in hot pond 4 got into independent waste heat discharge heat exchanger 6, the convection heat transfer was carried out to one secondary side of independent waste heat discharge heat exchanger 6, the coolant in hot pond 4 was cooled by independent waste heat discharge heat exchanger 6, get into after 5 cold pools and heated by reactor core 2, establish the difference in temperature between reactor core 2 and the independent waste heat discharge heat exchanger 6, form a return circuit natural circulation, derive the reactor core waste heat from reactor core 2 to hot pond 4.

Step 2, transferring the waste heat in the heat pool 4 to an intermediate loop through an independent waste heat discharge heat exchanger 6

Under the accident condition of the lead bismuth reactor, when the temperature of the hot pool in the reactor exceeds 600 ℃, an electromagnetic valve opening signal is triggered, the electromagnetic valve is automatically opened, the intermediate circuit coolant starts to flow after being heated in the independent waste heat discharge heat exchanger 6, the heated coolant is cooled in the air cooler 7, the temperature difference is established between the independent waste heat discharge heat exchanger 6 and the air cooler 7, the natural circulation of the intermediate circuit is formed, and the waste heat in the hot pool 4 is transferred to the intermediate circuit.

Step 3, establishing stable intermediate loop natural circulation and transferring the waste heat of the reactor core to the outside air

And opening an air door of the air cooler 7, and performing heat convection on cold air and the coolant of the intermediate loop in the air cooler 7 to enable the intermediate loop to establish stable natural circulation, so that the heat of the coolant of the intermediate loop is transferred to the air, and finally the waste heat of the reactor core is transferred to the external air.

The present invention has been described in detail with reference to the drawings and examples, but the present invention is not limited to the examples, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present invention. The prior art can be adopted in the content which is not described in detail in the invention.