阅读说明：本技术 一种利用压力容器壁面冷却的热管堆非能动余热排出系统 (passive waste heat removal system of heat pipe stack cooled by wall surface of pressure container ) 是由 夏庚磊 彭敏俊 朱海山 张元东 唐松胜 吕联鑫 于 2019-10-14 设计创作，主要内容包括：本发明涉及一种利用压力容器壁面冷却的热管堆非能动余热排出系统,属于核反应堆系统技术领域。包括反应堆保护容器和反应堆压力容器；反应堆保护容器的下部通过海水进口管道与大海环境相连,上部通过海水出口管道与大海环境相连；反应堆压力容器内布置有反应堆堆芯、高温热管和主换热器,反应堆压力容器的内表面与穿过堆芯布置的热管冷凝段相连；反应堆保护容器、海水进口管道、海水出口管道和反应堆压力容器共同构成与大海环境联通的余热排出通道。本发明形成的非能动余热排出循环仅依靠工质的密度差和热管的毛细作用,不需任何的外力作用就能实现堆芯衰变热的持续导出,提高了反应堆的安全性,且有利于实现反应堆结构的紧凑性,应用前景广阔。(The invention relates to a heat pipe reactor passive residual heat removal system utilizing wall cooling of a pressure vessel, belonging to the technical field of nuclear reactor systems and comprising a reactor protection vessel and a reactor pressure vessel, wherein the lower part of the reactor protection vessel is connected with the sea environment through a seawater inlet pipeline, the upper part of the reactor protection vessel is connected with the sea environment through a seawater outlet pipeline, a reactor core, a high-temperature heat pipe and a main heat exchanger are arranged in the reactor pressure vessel, the inner surface of the reactor pressure vessel is connected with a heat pipe condensation section arranged through the reactor core, and the reactor protection vessel, the seawater inlet pipeline, the seawater outlet pipeline and the reactor pressure vessel jointly form a residual heat removal channel communicated with the sea environment.)

The heat pipe reactor passive residual heat removal system utilizing the wall surface cooling of the pressure vessel is characterized by comprising a reactor protection vessel, a reactor pressure vessel, a seawater inlet pipeline, a seawater outlet pipeline and a residual heat removal channel, wherein the lower part of the reactor protection vessel is connected with the sea environment through the seawater inlet pipeline, the upper part of the reactor protection vessel is connected with the same sea environment through the seawater outlet pipeline, a reactor core, a high-temperature heat pipe reactor and a main heat exchanger are arranged in the reactor pressure vessel, the inner surface of the reactor pressure vessel is connected with a heat pipe condensation section arranged through the reactor core, and the reactor protection vessel, the seawater inlet pipeline, the seawater outlet pipeline and the reactor pressure vessel jointly form the residual heat removal channel communicated with the sea environment.

2. The passive waste heat removal system for a heat pipe stack cooled by a wall surface of a pressure vessel is characterized in that a seawater outlet pipeline is positioned at the upper part of a reactor protection vessel, the height of the seawater outlet pipeline in the height direction is higher than that of a seawater inlet pipeline, an isolation valve is arranged on the seawater outlet pipeline, and the isolation valve on the seawater inlet pipeline and the isolation valve on the seawater outlet pipeline are automatically opened under the power-off working condition of a marine nuclear reactor.

3. The passive residual heat removal system for a heat pipe stack cooled by the wall surface of a pressure vessel according to claim 1 or 2, wherein the residual heat removal channel is filled with inert gas.

4. The passive waste heat removal system for heat pipe stacks cooled by the wall surface of a pressure vessel according to claim 1 or 2, wherein the high-temperature heat pipe stacks are arranged in the metal matrix of the core active area, and part of the high-temperature heat pipes in the high-temperature heat pipe stacks are double-ended heat pipes.

5. The passive residual heat removal system for heat pipe stacks cooled by the wall surface of a pressure vessel is characterized in that the high-temperature heat pipe stacks are arranged in a metal matrix in a core active area, and part of high-temperature heat pipes in the high-temperature heat pipe stacks are double-ended heat pipes.

6. The passive residual heat removal system for a heat pipe stack cooled by the wall of a pressure vessel is characterized in that two ends of the double-ended heat pipe are respectively provided with a condensation section, the middle part of the double-ended heat pipe is provided with an evaporation section, the evaporation section is positioned in the core active area, the end of the condensation section is inserted into the main heat exchanger, and the end of the condensation section extends out of the bottom of the core active area.

7. The passive residual heat removal system for a heat pipe stack cooled by the wall of a pressure vessel is characterized in that a condensation section of the double-ended heat pipe is bent according to the inner surface structure of the lower chamber of the pressure vessel and is tightly attached and welded with the inner surface of the pressure vessel of the reactor.

8. The passive residual heat removal system for a heat pipe reactor cooled by the wall of a pressure vessel is characterized in that fins are welded on the outer surface of the reactor pressure vessel.

9. The passive residual heat removal system for a heat pipe reactor cooled by the wall of a pressure vessel is characterized in that fins are welded on the outer surface of the reactor pressure vessel.

10. The passive residual heat removal system for a heat pipe stack cooled by the wall surface of a pressure vessel according to claim 6 or 7, wherein fins are welded to the outer surface of the reactor pressure vessel.

Technical Field

The invention relates to an passive waste heat removal system of a heat pipe reactor cooled by utilizing a wall surface of a pressure vessel, belonging to the technical field of nuclear reactor systems.

Background

The derivation of reactor core decay heat after reactor shutdown is the safety problem that needs attention in the design of nuclear reactor, especially after a reactor power failure accident, the in-reactor waste heat cannot be derived by external power, and the in-reactor heat accumulation may cause the temperature rise of fuel elements to damage or even melt, thereby causing the leakage of radioactive substances and causing a very serious nuclear safety accident.

The high temperature heat pipe reactor is different from the pressurized water reactor, and is novel reactor forms which utilize the two-phase natural circulation of the coolant in the high temperature heat pipe to derive the heat of the reactor core, the heat pipe cooling reactor has good reliability and optimal thermal transient feedback performance, each heat pipe is independent, after a single heat pipe or a plurality of heat pipes are damaged, the heat can be derived out of the reactor through the adjacent heat pipe, the failure of the reactor system can not be caused, the intrinsic safety of the reactor is greatly improved, the heat pipe cooling reactor is a hotspot developed by the current small-sized reactors, and various design schemes of the heat pipe reactor are proposed abroad.

In the process of exporting the residual decay heat of the reactor, the active circulation cooling mode is still used as the main mode abroad, and a cooling working medium is provided by a circulating pump specially arranged in to cool the reactor.

Most of the current advanced reactor designs adopt passive safety concepts to improve the intrinsic safety of the reactor. The passive safety system does not depend on external trigger and a power source, and mainly depends on natural characteristics such as natural convection, gravity and the like to realize the functions of the safety system. The structural form and the operation mode of the high-temperature heat pipe reactor are greatly different from those of a conventional power station, and how to realize the derivation of the decay heat of the reactor core in a passive mode becomes a technical problem which needs to be solved urgently.

Disclosure of Invention

The invention aims to provide passive waste heat removal systems of a heat pipe stack, which utilize the wall surface of a pressure container for cooling, in order to reduce the release of radioactive substances to the maximum extent and ensure the safety of the reactor.

The purpose of the invention is realized as follows: the device comprises a reactor protection container, a reactor pressure container, a seawater inlet pipeline, a seawater outlet pipeline and a waste heat discharge channel; the lower part of the reactor protection container is connected with the sea environment through a seawater inlet pipeline, and the upper part of the reactor protection container is connected with the same sea environment through a seawater outlet pipeline; the reactor pressure vessel is internally provided with a reactor core, a high-temperature heat pipe reactor and a main heat exchanger, and the inner surface of the reactor pressure vessel is connected with a heat pipe condensation section which penetrates through the reactor core; the reactor protection container, the seawater inlet pipeline, the seawater outlet pipeline and the reactor pressure container jointly form a waste heat discharge channel communicated with the sea environment.

The invention also comprises structural features:

1. the seawater outlet pipeline is positioned at the upper part of the reactor protection container, and the height of the seawater outlet pipeline in the height direction is higher than that of the seawater inlet pipeline; an isolating valve is arranged on the seawater inlet pipeline; an isolating valve is arranged on the seawater outlet pipeline; the isolation valve on the seawater inlet pipeline and the isolation valve on the seawater outlet pipeline are automatically opened under the power-off working condition of the marine nuclear reactor.

2. And inert gas is filled in the waste heat discharge channel.

3. The high-temperature heat pipe stack is arranged in a metal matrix of a core active area, and part of high-temperature heat pipes in the high-temperature heat pipe stack are double-ended heat pipes.

4. The two ends of the double-end heat pipe are both condensation sections, the middle part of the double-end heat pipe is an evaporation section, the evaporation section of the heat pipe is positioned in the core active area, the end of the condensation section of the heat pipe is inserted into the main heat exchanger, and the end of the condensation section of the heat pipe extends out of the bottom of the core active area.

5. And the condensation section of the double-end heat pipe is bent according to the inner surface structure of the lower cavity of the pressure vessel and is tightly attached and welded with the inner surface of the reactor pressure vessel.

6. Fins are welded on the outer surface of the reactor pressure vessel.

Compared with the prior art, the passive waste heat discharge system has the advantages that the annular space between the heat pipe reactor pressure container and the protection container is utilized to form a waste heat discharge channel together with the seawater inlet pipeline and the seawater outlet pipeline , decay heat of the reactor core is transferred to the wall surface of the reactor pressure container by the high-temperature heat pipe, the wall surface of the pressure container is cooled by seawater in the waste heat discharge channel, and finally the decay heat of the reactor is led out to the sea environment.

Drawings

Fig. 1 is an overall configuration diagram of passive waste heat removal systems of a heat pipe stack using wall cooling of a pressure vessel according to the present invention.

Detailed Description

The present invention is described in further detail with reference to the drawings and the detailed description, it is to be understood that the described embodiments are only a partial embodiment , rather than a full embodiment.

As shown in the attached drawing 1, the overall structure diagram of heat pipe reactor passive residual heat removal systems utilizing pressure vessel wall cooling comprises a reactor protection vessel 1, the lower part of the reactor protection vessel 1 is connected with the sea environment through a seawater inlet pipeline 2, the upper part of the reactor protection vessel 1 is connected with the same sea environment through a seawater outlet pipeline 3, a reactor pressure vessel 4, a reactor core 5, a high-temperature heat pipe 6 and a main heat exchanger 7 are arranged in the reactor pressure vessel 4, the inner surface of the reactor pressure vessel 4 is connected with a heat pipe condensation section arranged through the reactor core, and the seawater inlet pipeline 2, the reactor protection vessel 1, the reactor pressure vessel 4 and the seawater outlet pipeline 3 jointly form a residual heat removal channel 8 communicated with the sea environment.

In a deep sea application environment, when a reactor power-off accident occurs, the high-temperature heat pipe 6 arranged in the main heat exchanger 7 loses cooling, and the waste heat in the reactor core 5 is transferred to the reactor pressure vessel 4 through two-phase natural circulation of alkali metal in the high-temperature heat pipe 6; the temperature of the cooling medium in the waste heat discharge channel 8 rises after receiving the heat of the reactor pressure vessel 4, the cooling medium flows upwards along the waste heat discharge channel 8 under the action of buoyancy, single-phase natural circulation is formed, and the heat is finally led out to the sea environment.

The seawater outlet pipe 3 is located at an upper portion of the reactor protection vessel 1, which is higher than the seawater inlet pipe 2 in a height direction. The larger the height difference between the seawater inlet pipeline 2 and the seawater outlet pipeline 3 is, the larger the buoyancy lift force of the seawater obtained in the residual heat discharge channel 8 is, and the larger the natural circulation flow rate is formed. Methods for improving natural circulation capacity by using the height difference of cold and heat sources are well known to those skilled in the art and will not be described in detail.

An isolating valve 9 is arranged on the seawater inlet pipeline 2; an isolating valve 10 is installed on the seawater outlet pipeline. When the reactor is in normal operation, the isolation valves 9 and 10 are both in a closed state. And inert gas is filled in the residual heat discharge channel 8 to isolate the reactor pressure vessel 4 from the reactor protection vessel 1. When the marine nuclear reactor is in a power-off working condition, the isolation valve 9 and the isolation valve 10 should be capable of being automatically opened, seawater enters the waste heat discharge channel 8 through the isolation valve 9 to cool the outer wall surface of the reactor pressure vessel 4, and the seawater with increased temperature flows out of the isolation valve 10 under the action of natural circulation driving force. The automatic opening mode of the isolation valve can adopt pneumatic or electric mode, the electric isolation valve must be equipped with a reliable power supply, and the logic is set to be automatically opened when power is cut off.

When the heat pipe stack is designed, high-temperature heat pipes 6 are inserted into the metal matrix of the core active area, the evaporation sections of the heat pipes are positioned in the core active area, the condensation sections of the heat pipes are positioned in the main heat exchanger, and the heat of the core is led out by utilizing the two-phase natural circulation of alkali metal in the high-temperature heat pipes.

In this embodiment, a part of the high-temperature heat pipes are double-ended heat pipes 11, for example, the high-temperature heat pipes at the outer end portion are double-ended heat pipes.

The middle part of the double-end heat pipe 11 is an evaporation section, and both ends of the double-end heat pipe are condensation sections, wherein the evaporation section of the heat pipe is positioned in the core active area, the end of the condensation section of the heat pipe is inserted into the main heat exchanger 7, and the other end of the condensation section of the heat pipe extends out of the bottom of the core active area.

The double-ended heat pipe 11 is vertically arranged, wherein a condensation section extending from the bottom of the reactor core is bent according to the structure of the inner surface of the reactor pressure vessel 4, and is closely welded to the inner surface of the reactor pressure vessel 4. The heat pipe stack can be operated under low pressure, and the pressure vessel does not need to bear high pressure, so the wall thickness of the reactor pressure vessel 4 is relatively thin, and the heat exchange area can be increased after the heat pipe stack is connected with a condensation section of the heat pipe.

Wherein, the outer surface of the reactor pressure vessel 4 is welded with fins 12, which can also play a role in increasing the heat exchange area.

In this embodiment, the number of the double-end heat pipes 11 may be determined according to reactor power, core arrangement, and residual heat removal requirements. After the reactor is shut down, the core decay heat will rapidly decrease to below 3%, and the number and arrangement of the double-ended heat pipes 11 may be determined according to the conditions of decay power, heat transfer efficiency of the heat pipes, heat exchange area of the reactor pressure vessel, etc., which are well known to those skilled in the art and will not be described in detail.

In summary, the invention discloses passive waste heat removal systems of heat pipe reactors cooled by utilizing wall surfaces of pressure vessels, which comprise a reactor protection vessel 1, wherein the bottom of the reactor protection vessel 1 is connected with the sea environment through a seawater inlet pipeline 2, the top of the reactor protection vessel is connected with the same sea environment through a seawater outlet pipeline 3, a reactor pressure vessel 4 is arranged in the reactor pressure vessel 4, a reactor core 5, a high-temperature heat pipe 6 and a main heat exchanger 7 are arranged in the reactor pressure vessel 4, the inner surface of the reactor pressure vessel 4 is connected with a heat pipe condensation section arranged through the reactor core, and the seawater inlet pipeline 2, the reactor protection vessel 1, the reactor pressure vessel 4 and the seawater outlet pipeline 3 form a waste heat removal channel communicated with the sea environment.