CN115966318A - Full-working-condition full-range passive residual heat removal system and method for reactor - Google Patents

Abstract

The invention discloses a full-working-condition full-range passive residual heat removal system and a method thereof for a reactor, wherein the reactor is arranged in a containment and comprises a primary side passive residual heat removal system, a secondary side passive residual heat removal system and a control system, the primary side passive residual heat removal system is provided with a first valve component, the secondary side passive residual heat removal system is provided with a second valve component, and the control system controls the start and stop of the primary side passive residual heat removal system and the secondary side passive residual heat removal system respectively by controlling the opening and closing of the first valve component and the second valve component. The full-working-condition full-range passive residual heat removal system and the method for the reactor reduce the heat transfer area of the primary side passive residual heat removal system, thereby reducing the damage risk of the heat exchange tube, avoiding the leakage of a primary loop coolant containing radioactivity of the reactor from the boundary of the primary loop coolant, greatly reducing the volume of the primary side passive residual heat removal system, reducing the volume of a water changing tank in a containment vessel and reducing the construction cost.

Description

Full-working-condition full-range passive residual heat removal system and method for reactor

Technical Field

The invention relates to the field of nuclear power plant system equipment and safety, in particular to a full-working-condition full-range passive waste heat discharging system and a full-working-condition full-range passive waste heat discharging method for a reactor.

Background

The waste heat discharged by the reactor refers to the heat which is discharged from the reactor core after the reactor is shut down and mainly comprises decay heat. For the reactor shutdown under the normal operation condition and the reactor shutdown under the accident operation condition, the waste heat of the reactor core needs to be discharged. For the reactor shutdown under normal operation conditions, the reactor core waste heat needs to be discharged mainly in the reactor starting and shutdown stages; for the reactor shutdown under the accident operation condition, the reactor core waste heat needs to be discharged mainly after the emergency shutdown of the reactor.

The reactor is required to go through the stage of the reactor temperature from high to low, namely, the reactor temperature is reduced from high temperature to low temperature by discharging the waste heat.

In the existing method for discharging waste heat after reactor shutdown of a nuclear power plant, the following 3 existing technologies exist, respectively:

prior art 1: and (3) discharging waste heat under normal operation conditions: SG is adopted for heat removal at a high-temperature stage, and a normal waste heat removal system is adopted at a low-temperature stage;

waste heat discharge under the accident operation condition: and a primary side waste heat discharge heat exhaust system is adopted in a high-temperature stage, and a normal waste heat discharge system is adopted in a low-temperature stage.

Prior art 2: and (3) discharging waste heat under normal operation conditions: SG is adopted for heat removal in a high-temperature stage, and a normal waste heat removal system is adopted in a low-temperature stage;

waste heat discharge under the accident operation condition: SG heat removal or secondary side passive waste heat removal is adopted in a high-temperature stage, and a normal waste heat removal system is adopted in a low-temperature stage.

Prior art 3: waste heat discharge under normal operation conditions: SG is adopted for heat removal in a high-temperature stage, a secondary side passive waste heat removal system is adopted for heat removal in a medium-temperature stage, and pool water is adopted for soaking the pressure vessel and the reactor core for heat removal in a low-temperature stage (less than or equal to 180 ℃);

waste heat discharge under the accident operation condition: secondary side passive waste heat is used for discharging heat in a high-temperature stage, and pool water is used for soaking the pressure vessel and the reactor core to discharge heat in a low-temperature stage (less than or equal to 180 ℃).

One disadvantage of the secondary side passive residual heat removal system in the prior art is that the secondary side passive residual heat removal system needs to use a steam generator as a secondary side heat transfer interface, and the system itself needs to use an out-of-containment heat exchanger located in an air cooling tower (or in a cooling water tank) as two three side heat transfer interfaces, so that there are 2 thermal resistances for heat transfer in total, and the total thermal resistance is large, so that the primary side of the reactor cannot be reduced to a low temperature. According to the simulation calculation result of reducing the temperature of the primary side of the reactor in the prior art 3, the result shows that the temperature difference between the primary side and the tertiary side is smaller and smaller along with the reduction of the temperature of the primary side, so that the heat transfer power is smaller and smaller, the reduction rate of the temperature of the primary side is slower and slower, finally, after the temperature of the primary side is reduced to about 180 ℃, the heat transfer temperature difference is limited to be very small, and the temperature of the primary side can not be reduced any more. At this time, it is necessary to switch to another waste heat removal system to perform heat removal and temperature reduction of the primary side, such as an active waste heat removal system (normal waste heat removal system) directly connected to the primary side of the reactor.

The passive waste heat eduction gear of primary side among the prior art, directly link with the reactor primary side, there are more heat exchange tubes on this system. The heat exchange tubes are directly connected with the primary side of the reactor, so that the boundary of a loop is expanded equivalently, and the tube walls of the heat exchange tubes are thinner, so that the risk of damaging the boundary of the loop is increased.

In addition, the primary side waste heat removal system contains a primary radioactive fluid, and a safety barrier (containment) is omitted compared with the secondary side passive waste heat removal system, so that the primary waste heat removal system is required to be arranged in the containment. If the volume (capacity) of the primary side waste heat removal system is large, the volume and arrangement in the containment can be affected.

In summary, the following defects exist in the prior art:

1. the passive residual heat removal under the full-range working condition cannot be realized, and in the current nuclear power plant, no matter the prior art 2 or the prior art 1, a normal residual heat removal system is configured for realizing the residual heat removal in a low state (when the temperature of a primary side is low), and the system is an active system;

2. the primary side of the reactor cannot be reduced to a lower temperature, in the current nuclear power plant, a secondary side passive waste heat removal system needs to use a steam generator as a heat transfer interface, and the system itself needs to transfer heat to a cooling water tank positioned on the tertiary side by using the steam generator as the heat transfer interface, so that two heat transfer resistances exist in total, the total heat resistance is large, and the primary side of the reactor cannot be reduced to a lower temperature;

3. the primary side passive waste heat removal device is directly connected with the primary side of the reactor, and the total area of heat exchange tubes of the heat exchanger of the primary side passive waste heat removal device is large, so that a large risk of damage to a boundary heat exchange tube of a primary loop exists. The heat exchange tubes are directly connected with the primary side of the reactor, so that the boundary of a loop is expanded equivalently, the more the heat exchange tubes are, the larger the boundary surface is, and the risk of damage to the boundary of the loop is increased;

4. the primary side waste heat removal system contains a primary radioactive fluid, and compared with the secondary side passive waste heat removal system, a safety barrier (containment) is omitted, so that the primary side waste heat removal system is required to be arranged in the containment to enhance the radioactive barrier. The primary side passive waste heat removal device is adopted, and a large-volume cooling water tank needs to be arranged in the containment. If the volume (capacity) of the primary side waste heat exhaust system and a cooling water tank of the primary side waste heat exhaust system are increased, more space in a containment vessel is occupied, the containment vessel is larger, and the arrangement of other system equipment in the safety vessel is influenced. The containment volume becomes large and the construction cost becomes high.

Disclosure of Invention

The invention aims to provide a full-working-condition full-range passive residual heat removal system and method for a reactor.

The technical scheme adopted by the invention for solving the technical problem is as follows: the utility model provides a full active exhaust waste heat system of full operating mode full range non-of structure reactor, the reactor is located in the containment, just the reactor is connected with heat pipe and cold pipe, and it includes: the system comprises a primary side passive waste heat discharge system, a secondary side passive waste heat discharge system and a control system;

the primary side passive waste heat removal system is arranged in the containment and comprises a primary side heat removal loop, two ends of the primary side heat removal loop are respectively connected with the heat pipe and the cold pipe, and a first valve assembly is arranged on the primary side heat removal loop;

the secondary side passive waste heat discharge system is arranged outside the containment and comprises a secondary side heat discharge loop, and a second valve assembly is arranged on the secondary side heat discharge loop;

the control system controls the start and stop of the primary side passive waste heat discharge system and the secondary side passive waste heat discharge system respectively by controlling the opening and closing of the first valve assembly and the second valve assembly, so that the control method of the reactor full-working-condition full-range passive waste heat discharge system under different working conditions of the reactor is realized.

In some embodiments, the system further comprises a steam generator, one end of the steam generator is connected with the cold pipe, and a steam outlet pipeline and a water inlet pipeline are connected with the steam generator;

and two ends of the secondary side heat removal loop are respectively connected with the steam outlet pipeline and the water inlet pipeline.

In some embodiments, the primary side passive waste heat removal system comprises a first heat exchanger arranged on the primary side heat removal circuit, and a water exchange tank is arranged on the periphery of the first heat exchanger;

the height of the water changing tank relative to the bottom of the containment vessel is higher than that of the reactor relative to the bottom of the containment vessel.

In some embodiments, the cross section of the water change box is matched with the shape of the inner wall surface of the containment so as to transfer the heat of the water change box to the wall surface of the containment, and a ventilation opening is arranged on the water change box.

In some embodiments, the primary heat rejection circuit includes a heat exchanger inlet line and a heat exchanger outlet line;

the heat exchanger inlet line is connected to the first end of the first heat exchanger and the heat pipe;

the heat exchanger outlet line is connected to the second end of the first heat exchanger and the cold pipe.

In some embodiments, the first valve assembly comprises a first control valve, a second control valve, a third control valve, and a flow valve;

the first control valve is arranged on the heat exchanger inlet pipeline;

the second control valve, the third control valve and the flow valve are separately arranged on an outlet pipeline of the heat exchanger, and the second control valve and the third control valve are connected in parallel and then connected in series with the flow valve to be commonly used for adjusting the flow on the outlet pipeline of the heat exchanger.

In some embodiments, the secondary side passive waste heat removal system comprises an air cooling tower and a second heat exchanger arranged in the air cooling tower;

the air cooling tower is arranged outside the containment vessel, and the height of the air cooling tower relative to the bottom of the containment vessel is higher than that of the reactor relative to the bottom of the containment vessel.

In some embodiments, the secondary side heat rejection circuit comprises a steam removal line and a water return line;

the steam removal pipeline is connected to the steam outlet pipeline and the first end of the second heat exchanger;

the water return pipeline is connected to the water inlet pipeline and the second end of the second heat exchanger.

In some embodiments, the second valve assembly includes a fourth control valve disposed on the de-steaming line and a fifth control valve disposed on the water return line;

and when the control system starts the secondary side passive waste heat discharging system, the fourth control valve and the fifth control valve are opened.

In some embodiments, a water replenishing pipeline is connected between the steam removing pipeline and the water returning pipeline;

a water replenishing tank is arranged on the water replenishing pipeline and used for replenishing water to the secondary side passive waste heat discharging system;

a sixth control valve is arranged between the water replenishing tank and the water return pipeline;

and a seventh control valve is arranged between the water replenishing tank and the steam removal pipeline.

In some embodiments, the steam generator is further provided with a main pump and a driving motor connected with the main pump, and the heat pipe is provided with a voltage stabilizer.

In this embodiment, a full-operating-condition full-range passive residual heat removal method for a reactor is also constructed, and is applied to the full-operating-condition full-range passive residual heat removal system for the reactor, and the method includes the following steps:

step S1: establishing a reactor full-working-condition full-range passive waste heat discharging system;

step S2: according to different working conditions and running states of the reactor, the control system controls the start and stop of the primary side passive waste heat discharge system and the secondary side passive waste heat discharge system to complete the discharge of the waste heat of the reactor.

In some embodiments, in the step S2, based on that the reactor is in normal operation, when the reactor operating condition is a thermal shutdown operating condition, the control system controls the secondary side passive waste heat removal system to start;

when the working condition of the reactor is a safe shutdown working condition, the control system controls the secondary side passive waste heat discharge system to be started;

when the working condition of the reactor is a transition working condition, the control system controls the primary side passive waste heat discharge system to be started;

and when the working condition of the reactor is a material changing working condition, directly injecting water in the water changing tank into the reactor.

In some embodiments, in the step S2, based on that the reactor is in the accident operation, when the reactor operating condition is a thermal shutdown operating condition, the control system controls the secondary side passive waste heat removal system to start;

when the working condition of the reactor is a safe shutdown working condition, the control system controls the secondary side passive waste heat discharge system to be started;

and when the working condition of the reactor is a transition working condition, the control system controls the primary side passive waste heat removal system to be started.

In some embodiments, the hot shutdown condition is the reactor reactivity less than 0.99 and the reactor primary side temperature is 300 ℃;

the safe shutdown working condition is that the reactor reactivity is less than 0.99 and the temperature of the primary side of the reactor is more than 180 ℃ and less than 300 ℃;

the transition working condition is that the reactor reactivity is less than 0.95 and the temperature of the primary side of the reactor is more than 80 ℃ and less than or equal to 180 ℃;

the refueling working condition is that the reactor reactivity is less than 0.95, and the temperature of the primary side of the reactor is more than or equal to 20 ℃ and less than or equal to 80 ℃.

The implementation of the invention has the following beneficial effects: the full-range passive residual heat removal system and method for the full-range working condition of the reactor can adopt the passive residual heat removal system for the full-range working condition. The invention provides a method for discharging waste heat by dividing waste heat into three stages, and adopting different passive systems to discharge the waste heat, thereby reducing the heat transfer area of a primary side passive waste heat discharging system, reducing the damage risk of a heat exchange tube and avoiding the leakage of a primary loop coolant containing radioactivity of a reactor from the boundary thereof; and the volume of the primary side passive waste heat discharge system can be greatly reduced, the volume of a water changing tank in the containment is reduced, and the construction cost is reduced.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the present invention will be further described with reference to the accompanying drawings and embodiments, it is to be understood that the following drawings only show some embodiments of the present invention and therefore should not be considered as limiting the scope, and that other relevant drawings can be obtained from these drawings by those skilled in the art without inventive effort. In the drawings:

FIG. 1 is a schematic illustration of different heat rejection methods under different conditions and different stages of the prior art and the present embodiment;

FIG. 2 is a schematic diagram of a full-range passive residual heat removal system for a full-range of reactor operating conditions in some embodiments of the present disclosure;

FIG. 3 is a schematic diagram of the primary side passive residual heat removal system in some embodiments of the present invention;

FIG. 4 is a schematic diagram of a secondary side passive residual heat removal system according to some embodiments of the present invention;

FIG. 5 is a schematic diagram of the use of a full-range passive waste heat removal system for the full operating conditions of a reactor in some embodiments of the present invention under different operating conditions.

Detailed Description

For a more clear understanding of the technical features, objects, and effects of the present invention, embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the following description, it is to be understood that the orientations and positional relationships indicated by "front", "rear", "upper", "lower", "left", "right", "longitudinal", "lateral", "vertical", "horizontal", "top", "bottom", "inner", "outer", "leading", "trailing", and the like are configured and operated in specific orientations based on the orientations and positional relationships shown in the drawings, and are only for convenience of describing the present invention, and do not indicate that the device or element referred to must have a specific orientation, and thus, are not to be construed as limiting the present invention.

It is also noted that, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," "disposed," and the like are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. When an element is referred to as being "on" or "under" another element, it can be "directly" or "indirectly" on the other element or intervening elements may also be present. The terms "first", "second", "third", etc. are only for convenience in describing the present technical solution, and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated, whereby the features defined as "first", "second", "third", etc. may explicitly or implicitly include one or more of such features. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Referring to fig. 2 to 4, in some embodiments of the present invention, a full-range passive waste heat removal system for a reactor under all operating conditions is provided, which is used for removing waste heat of a reactor 4 under normal operating conditions and accident operating conditions, the reactor 4 is disposed in a containment 5, the reactor 4 is connected to a heat pipe 41 and a cold pipe 42, and includes a primary passive waste heat removal system 1, a secondary passive waste heat removal system 2, a steam generator 3, and a control system, the primary passive waste heat removal system 1 is disposed in the containment 5 and includes a primary heat removal loop, two ends of the primary heat removal loop are respectively connected to the heat pipe 41 and the cold pipe 42, the primary heat removal loop is provided with a first valve assembly 15, the secondary passive waste heat removal system 2 is disposed outside the containment 5 and includes a secondary heat removal loop, the secondary heat removal loop is provided with a second valve assembly 26, and the control system controls opening and closing of the first valve assembly 15 and the second valve assembly 26 to respectively control the start and stop of the passive waste heat removal system 1 and the secondary passive waste heat removal system 2, so as to implement a full-range passive waste heat removal system for controlling the reactor under all operating conditions. Fig. 1 is a schematic diagram of different heat removal methods under different working conditions and different stages in the prior art and the embodiment.

It is understood that the primary side passive residual heat removal system 1 is used for removing reactor residual heat in a first temperature range, the secondary side passive residual heat removal system 2 is connected with the steam generator 3, and the secondary side passive residual heat removal system 2 is used for removing reactor residual heat in a second temperature range. Wherein the first temperature range is 80 ℃ to 180 ℃, and the second temperature range is 180 ℃ to 300 ℃.

Specifically, the full operating condition includes both a normal operating condition and an accident operating condition. The full range refers to the full range of temperatures from high to low applicable to the primary side of the reactor. The full-working-condition full-range passive residual heat removal system of the reactor is suitable for a normal residual heat removal system and an accident residual heat removal system, wherein when the reactor 4 normally runs, for example, when the reactor 4 is started or stopped, if the reactor 4 does not have the condition of transferring heat to the secondary side, if the water level of a primary loop of the reactor 4 is too low, or if the steam power conversion equipment or the steam absorption equipment of the secondary side does not reach the running condition, the residual heat of the reactor 4 is removed through the normal residual heat removal system of the reactor 4 at the moment. When the reactor 4 has accident emergency accident condition, the normal heat discharge way of the reactor 4 takes away heat through the steam generator 3, the heat is taken away through the normal waste heat discharge system and damaged, the heat of the primary side of the reactor and the reactor core can not be normally discharged, the high-temperature and high-pressure state can occur at the primary side of the reactor, so the reactor core can be further heated to lead fuel damage, at the moment, the emergency waste heat discharge system is needed to play a role in taking away the heat of a primary loop and the reactor core of the reactor 4, so the reactor 4 can be provided with the emergency waste heat discharge system for heat discharge under the emergency, and the full-working-condition full-range passive waste heat discharge system of the reactor can play an emergency waste heat discharge role at the moment.

The passive residual heat removal system is an active component independent of power supply and similar main pumps, can naturally remove heat only by natural driving force such as natural circulation, gravity, capillary force and the like, ensures that the reactor core of the reactor 4 is kept in a cooled state, and has high system reliability.

In some embodiments, one end of the steam generator 3 is connected to a cold pipe 42 for converting water into steam by using the waste heat transmitted through the cold pipe 42, and the steam generator 3 is connected to a steam outlet line 31 and a water inlet line 32, and two ends of the secondary heat rejection loop are connected to the steam outlet line 31 and the water inlet line 32, respectively. Further, a main pump 33 and a driving motor connected to the main pump 33 are disposed on the steam generator 3, the main pump 33 is used for driving the waste heat through the cold pipe 42 to the steam generator 3, and the driving motor is used for driving the main pump 33 to operate.

Further, as shown in fig. 3, the primary side passive residual heat removal system 1 includes a first heat exchanger 12 disposed on a primary side heat removal circuit 13, a water exchange tank 11 is disposed around the first heat exchanger 12, and the primary side passive residual heat removal system 1 and the steam generator 3 are both disposed in the containment 5. It is understood that the first heat exchanger 12 may preferably be a passive waste heat removal heat exchanger, and the primary side passive waste heat removal system 1 drives the reactor primary side coolant from the heat pipe 41 into the first heat exchanger 12 and then back to the cold pipe 42 by means of natural circulation generated between the cold source of the first heat exchanger 12 and the core heat source of the reactor 4, and the first heat exchanger 12 removes the reactor 4 waste heat into the water replacement tank 11.

The heat pipe 41 is further provided with a voltage stabilizer 411, and the voltage stabilizer 411 stabilizes the power supply voltage which has large fluctuation and cannot meet the requirements of the electrical equipment within a set value range, so that various circuits or the electrical equipment can normally work under the rated working voltage. The voltage stabilizer 411 is composed of a voltage regulating circuit, a control circuit, a servo motor and the like, when the input voltage or load changes, the control circuit performs sampling, comparison and amplification, then drives the servo motor to rotate, and changes the position of a carbon brush of the voltage regulator so as to ensure the normal working operation of the reactor full-working-condition full-range passive waste heat removal system.

Preferably, the height of the water change tank 11 relative to the bottom of the containment vessel 5 is higher than the height of the reactor 4 relative to the bottom of the containment vessel 5. It can be understood that the water changing tank 11 is placed in the containment 5 at a position having a certain height difference with respect to the reactor core of the reactor 4, so that the height difference beneficial to natural circulation is formed between the first heat exchanger 12 and the reactor core, and the stability and convenience of the primary side passive residual heat removal system 1 during operation are ensured.

Further, the cross-sectional shape of the water change tank 11 is matched with the shape of the inner wall surface of the containment 5 so as to transfer the heat of the water change tank 11 to the wall surface of the containment 5, and a ventilation opening 111 is formed in the water change tank 11 for ventilation and heat dissipation of the water change tank 11. In the present embodiment, the inner wall surface of the containment vessel 5 is circular, the cross-sectional shape of the safe replacement tank 11 in plan view is circular, and the outer wall thereof is in close contact with the inner wall surface of the containment vessel 5, so that the heat of the safe replacement tank 11 is transferred to the steel wall surface of the containment vessel 5, and then further transferred to the air on the outer wall surface of the containment vessel 5, and finally the outer wall surface of the containment vessel 5 is cooled by the flowing air. In other embodiments, the cross-sectional shape of the water changing tank 11 in the top view may be a rectangle, an ellipse or other shapes, and only needs to match the shape of the wall surface of the safety shell 5, which is not limited herein. The water change tank 11 has a rectangular cross-sectional side view, and may have a steel cover at an upper end thereof, and the steel cover may have the ventilation opening 111 therein.

In some embodiments, the first valve assembly 15 includes a first control valve 131, a second control valve 141, a third control valve 142, and a flow valve 143, the first control valve 131 is disposed on the heat exchanger inlet line 13, the second control valve 141, the third control valve 142, and the flow valve 143 are separately disposed on the heat exchanger outlet line 14, and the second control valve 141 and the third control valve 142 are connected in parallel and then connected in series with the flow valve 143 to adjust the flow on the heat exchanger outlet line 14.

It will be appreciated that the first control valve 131 may be an isolation valve which is maintained in a normally open state on the inlet line to maintain the pressure of the coolant system of the reactor 4 to fill the first heat exchanger 12 with the low-temperature coolant, thereby enhancing the operation efficiency of the first heat exchanger 12, and the second control valve 141 and the third control valve 142 may be pneumatic valves. Further, when the control system starts the primary side passive residual heat removal system 1, the second control valve 141 and the third control valve 142 are opened. It is understood that the primary side passive residual heat removal system 1, upon receiving the start trigger signal, automatically opens the second control valve 141 and the third control valve 142 at the same time, thereby generating a natural circulation head of the coolant of the reactor 4 due to the difference in level and temperature between the first heat exchanger 12 and the reactor 4. The heat exchanger inlet pipeline 13 and the heat exchanger outlet pipeline 14 may further be provided with a filter for intercepting various contaminants such as abrasive particles generated by the hydraulic elements of the primary side passive residual heat removal system 1 during operation, and may further be provided with a pressure gauge for measuring the flow pressure on the heat exchanger inlet pipeline 13 and the heat exchanger outlet pipeline 14.

As shown in fig. 4, the secondary passive residual heat removal system 2 includes an air cooling tower 21 and a second heat exchanger 22 disposed in the air cooling tower 21, the air cooling tower 21 is disposed outside the containment 5, and a height of the air cooling tower 21 with respect to a bottom of the containment 5 is higher than a height of the reactor 4 with respect to the bottom of the containment 5. It can be understood that the air cooling tower 21 is disposed outside the containment vessel 5 and is installed at a position higher than the reactor 4, so that the air cooling tower 21 has a certain height difference relative to the core, which facilitates the second heat exchanger 22 and the reactor 4 core to form a height difference favorable for natural circulation.

Further, the secondary side heat rejection circuit includes a steam removal line 23 and a water return line 24, the steam removal line 23 is connected to the steam outlet line 31 and the first end of the second heat exchanger 22, and the water return line 24 is connected to the water inlet line 32 and the second end of the second heat exchanger 22. It can be understood that the secondary side passive residual heat removal system 2 is engaged with the steam generator 3 to form a natural circulation loop, the steam generator 3 is a hot trap of the loop, and the second heat exchanger 22 is a cold trap of the loop, so as to remove the core residual heat of the primary loop of the reactor 4. The second heat exchanger 22 leads out the waste heat of the reactor core to a cooling water pool outside the containment 5 or conducts the waste heat to the air of the air cooling tower 21, and the cooling water in the water pool absorbs heat and is heated and evaporated.

In some embodiments, the second valve assembly 26 includes a fourth control valve 231 and a fifth control valve 241, the fourth control valve 231 is disposed on the steam removal line 23, the fifth control valve 241 is disposed on the water return line 24, and the fourth control valve 231 and the fifth control valve 241 may preferably be electrically controlled valves, which can be used to adjust the flow pressure on the secondary passive residual heat removal system 2. When the control system starts the secondary side passive residual heat removal system 2, the fourth control valve 231 and the fifth control valve 241 are opened, and then the secondary side passive residual heat removal system 2 automatically establishes natural circulation and then starts.

Furthermore, a water replenishing pipeline 25 is connected between the steam removing pipeline 23 and the water returning pipeline 24, a water replenishing tank 251 is arranged on the water replenishing pipeline 25, a sixth control valve 252 is arranged between the water replenishing tank 251 and the water returning pipeline 24, and a seventh control valve 253 is arranged between the water replenishing tank 251 and the steam removing pipeline 23. It will be appreciated that the makeup tank 251 is a tank type container in which low-temperature cooling water is filled, and upper and lower portions thereof are connected to a connection line, the upper connection line being connected to the steam removal line 23, and the lower connection line being connected to the return line 24. The water replenishing tank 251 can be used for replenishing water to the secondary side passive residual heat removal system 2 after an accident to avoid the water shortage in the device, the sixth control valve 252 and the seventh control valve 253 can be electric control valves, the sixth control valve 252 is used for controlling the water replenishing tank 251 to be opened and closed for replenishing water to the secondary side passive residual heat removal system 2, and the seventh control valve 253 is used for controlling the water from the steam removal pipeline 23 to enter the water replenishing tank 251 to be opened and closed.

In this embodiment, a full-operating-condition full-range passive residual heat removal method for a reactor is further constructed, which is respectively directed to post-shutdown residual heat removal under a normal operating condition and post-shutdown residual heat removal under an accident condition (as shown in fig. 5):

(1) Waste heat discharge after shutdown under normal operation condition

Operating mode (1) (as shown in fig. 5): when the reactivity of the reactor core is greater than or equal to 0.99 and the temperature of the primary side of the reactor is about 300 ℃, the reactor is operated at power without shutdown, and heat is discharged only by using the steam generator 3, which is not the case of the patent.

Operating mode (2) (as shown in fig. 5): when the reactor state parameter belongs to the parameter range of the hot shutdown working condition, the control system controls the secondary side passive waste heat discharge system 2 to start; operation mode (3): when the working condition of the reactor is a safe shutdown working condition, the control system controls the secondary side passive waste heat discharge system 2 to be started; operation mode (4): when the working condition of the reactor is a transition working condition, the control system controls the primary side passive waste heat discharging system 1 to be started; operation mode (5): when the working condition of the reactor is a refueling working condition, water in the refueling water tank 11 or the refueling water pool is directly injected into the reactor 4.

(2) Post-shutdown waste heat removal under accident conditions

Operating mode (2) (as shown in fig. 5): when the working condition of the reactor is a hot shutdown working condition, the control system controls the secondary side passive waste heat discharge system 2 to be started; operation mode (3): when the working condition of the reactor is a safe shutdown working condition, the control system controls the secondary side passive waste heat discharge system 2 to be started; operation mode (4): when the working condition of the reactor is a transition working condition, the control system controls the primary side passive waste heat discharging system 1 to be started. It can be understood that, under the accident operation condition, after the reactor 4 is in an emergency shutdown, protection signals such as "high hot leg temperature is high" are triggered, and these signals will trigger the fourth control valve 231 and the fifth control valve 241 of the secondary side passive residual heat removal system 2 to open, so as to start the secondary side passive residual heat removal system 2. The secondary side passive waste heat removal system 2 performs heat removal on the primary side of the reactor until the temperature of the primary side of the reactor reaches about 180 ℃. Then, the operator closes the secondary side passive residual heat removal system 2, starts the primary side passive residual heat removal system 1, and the primary side passive residual heat removal system 1 performs heat removal on the primary side of the reactor until the temperature of the primary side of the reactor reaches about 80 ℃.

In the working conditions, the hot shutdown working condition is that the reactivity of the reactor 4 is less than 0.99 and the temperature of the primary side of the reactor is 300 ℃; the safe shutdown working condition is that the reactivity of the reactor 4 is less than 0.99 and the temperature of the primary side of the reactor is more than 180 ℃ and less than 300 ℃; the transition working condition is that the reactivity of the reactor 4 is less than 0.95 and the temperature of the primary side of the reactor is more than 80 ℃ and less than or equal to 180 ℃; the refueling working condition is that the reactivity of the reactor 4 is less than 0.95 and the temperature of the primary side of the reactor is more than or equal to 20 ℃ and less than or equal to 80 ℃.

In order to further improve the space utilization rate of the reactor full-condition full-range passive residual heat removal system, reduce the size of the reactor full-condition full-range passive residual heat removal system and improve the economic benefit, the power of the first heat exchanger 12, the power of the second heat exchanger 22, the size of the air cooling tower 21 and the size of the water change tank 11 need to be determined.

Specifically, for determining the power of the second heat exchanger 22, the maximum heat removal power needs to be considered under the working condition of the secondary side passive waste heat removal system 2. The secondary side passive residual heat removal system 2 is started as soon as possible after the scram of the reactor 4, and the reactor 4 can contain a part of the residual heat of the reactor 4 by the self-cooled heat capacity after the scram, so that the heat exchange power of the second heat exchanger 22 is preferably 3% FP to 5% FP, where FP is the full power of the reactor 4.

For the determination of the size of the air cooling tower 21, the heat exchange power required to match the second heat exchanger 22 needs to consider the maximum heat rejection power under the working condition that the air cooling tower needs to be used. 3-5% FP to meet the heat exchange power requirement of the heat exchanger.

For determining the power of the first heat exchanger 12, the maximum heat removal power needs to be considered under the working condition that the primary side passive waste heat removal system 1 is used. Whether for normal operating conditions or accident operating conditions, the primary side passive waste heat removal system 1 is started after 24 hours, and other non-safety level cooling measures can be intervened when the device needs to act for 72 hours. Therefore, the core decay thermal power is about 0.7% FP when the maximum heat exchange power is the maximum value in all markets after 24 hours of shutdown.

For determining the volume of the water change tank 11, the action duration of the full-working-condition full-range passive waste heat discharging system of the reactor and the power of the heat to be discharged need to be considered. The volume of the water change tank 11 is calculated by calculating the integral quantity of decay heat 24 hours to 72 hours after the shutdown of the reactor 4, and then by further considering the latent heat and sensible heat of the coolant, the required quantity of water can be obtained. The primary side passive residual heat removal system 1 is used only for carrying heat at low temperature in a long-term stage, and therefore the power can be greatly reduced, meaning that the first heat exchanger 12 and the water change tank 11 can also be greatly reduced.

Understandably, the full-working-condition full-range passive residual heat removal system of the reactor has the beneficial effects that:

1. the passive residual heat removal of the whole working condition and the whole range working condition is realized, and the passive residual heat removal system is adopted for the whole range working condition. In the embodiment, the waste heat discharge is divided into three stages, and different passive systems are adopted for waste heat discharge;

2. in the embodiment, the primary side passive waste heat removal system 1 is only used for performing waste heat removal in a lower state, and at the moment, the waste heat of the reactor core is smaller, so that the volume capacity of the primary side passive waste heat removal system 1 and the volume of a cooling water tank in a containment can be greatly reduced, the total area of a heat transfer pipe of a heat exchanger is greatly reduced, and the risk of damage to the boundary of a primary loop is greatly reduced;

3. in the embodiment, the volume capacity of the primary side passive residual heat removal system 1 is greatly reduced, so that the volume of a water tank in the containment 5 can be greatly reduced, thereby being beneficial to reducing the volume of the containment 5 and reducing the construction cost.

It is to be understood that the foregoing examples, while indicating the preferred embodiments of the invention, are given by way of illustration and description, and are not to be construed as limiting the scope of the invention; it should be noted that, for those skilled in the art, the above technical features can be freely combined, and several changes and modifications can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention; therefore, all equivalent changes and modifications made within the scope of the claims of the present invention should be covered by the claims of the present invention.

Claims (15)

1. The utility model provides an active exhaust waste heat system of reactor full operating mode full range non, reactor (4) are located in containment (5), just reactor (4) are connected with heat pipe (41) and cold pipe (42), its characterized in that includes: a primary side passive waste heat discharge system (1), a secondary side passive waste heat discharge system (2) and a control system;

the primary side passive waste heat removal system (1) is arranged in the containment (5) and comprises a primary side heat removal loop, two ends of the primary side heat removal loop are respectively connected with the heat pipe (41) and the cold pipe (42), and a first valve assembly (15) is arranged on the primary side heat removal loop;

the secondary side passive waste heat discharge system (2) is arranged outside the containment (5) and comprises a secondary side heat discharge loop, and a second valve assembly (26) is arranged on the secondary side heat discharge loop;

the control system controls the start and stop of the primary side passive waste heat discharge system (1) and the secondary side passive waste heat discharge system (2) respectively by controlling the opening and closing of the first valve assembly (15) and the second valve assembly (26), so that the control method of the reactor full-working-condition full-range passive waste heat discharge system under different working conditions of the reactor (4) is realized.

2. The reactor full-working-condition full-range passive residual heat removal system according to claim 1, characterized by further comprising a steam generator (3), wherein one end of the steam generator (3) is connected with the cold pipe (42), and the steam generator (3) is connected with a steam outlet pipeline (31) and a water inlet pipeline (32);

and two ends of the secondary side heat removal loop are respectively connected with the steam outlet pipeline (31) and the water inlet pipeline (32).

3. The reactor full-range passive residual heat removal system according to claim 2, wherein the primary side passive residual heat removal system (1) comprises a first heat exchanger (12) arranged on the primary side heat removal loop, and a water exchange tank (11) is arranged around the first heat exchanger (12);

the height of the water change tank (11) relative to the bottom of the containment vessel (5) is higher than the height of the reactor (4) relative to the bottom of the containment vessel (5).

4. The system for discharging the residual heat passively in the full-range of the all-condition reactor according to claim 3, characterized in that the cross-sectional shape of the water changing tank (11) is matched with the shape of the inner wall surface of the containment (5) so as to transfer the heat of the water changing tank (11) to the wall surface of the containment, and a ventilation opening (111) is formed in the water changing tank (11).

5. The full-range passive residual heat removal system of claim 3, wherein the primary heat removal loop comprises a heat exchanger inlet line (13) and a heat exchanger outlet line (14);

the heat exchanger inlet line (13) is connected to a first end of the first heat exchanger (12) and to the heat pipe (41);

the heat exchanger outlet line (14) is connected to the second end of the first heat exchanger (12) and the cold pipe (42).

6. The full-range passive residual heat removal system of claim 5, wherein the first valve assembly (15) comprises a first control valve (131), a second control valve (141), a third control valve (142) and a flow valve (143);

the first control valve (131) is arranged on the heat exchanger inlet pipeline (13);

the second control valve (141), the third control valve (142) and the flow valve (143) are separately arranged on the heat exchanger outlet pipeline (14), and the second control valve (141) and the third control valve (142) are connected in parallel and then connected in series with the flow valve (143) to be commonly used for adjusting the flow on the heat exchanger outlet pipeline (14).

7. The full-working-condition full-range passive residual heat removal system of the reactor according to claim 6, characterized in that the secondary side passive residual heat removal system (2) comprises an air cooling tower (21) and a second heat exchanger (22) arranged in the air cooling tower (21);

the air cooling tower (21) is arranged outside the containment vessel (5), and the height of the air cooling tower (21) relative to the bottom of the containment vessel (5) is higher than that of the reactor (4) relative to the bottom of the containment vessel (5).

8. The full-range passive residual heat removal system for the full-operating-condition reactor of claim 7, wherein the secondary heat removal loop comprises a steam removal pipeline (23) and a water return pipeline (24);

the steam removal line (23) is connected to the steam outlet line (31) and to a first end of the second heat exchanger (22);

the water return line (24) is connected to the water inlet line (32) and a second end of the second heat exchanger (22).

9. The full-operating-condition full-range passive residual heat removal system of the reactor according to claim 8, wherein the second valve assembly (26) comprises a fourth control valve (231) arranged on the steam removal pipeline (23) and a fifth control valve (241) arranged on the water return pipeline (24);

when the control system starts the secondary side passive waste heat discharge system (2), the fourth control valve (231) and the fifth control valve (241) are opened.

10. The full-operating-condition full-range passive residual heat removal system of the reactor according to claim 9, characterized in that a water replenishing pipeline (25) is connected between the steam removal pipeline (23) and the water return pipeline (24);

a water replenishing tank (251) is arranged on the water replenishing pipeline (25), and the water replenishing tank (251) is used for replenishing water to the secondary side passive waste heat discharging system (2);

a sixth control valve (252) is arranged between the water replenishing tank (251) and the water return pipeline (24);

a seventh control valve (253) is arranged between the water replenishing tank (251) and the steam removing pipeline (23).

11. The full-working-condition full-range passive residual heat removal system of the reactor according to claim 2, wherein a main pump (33) and a driving motor connected with the main pump (33) are further arranged on the steam generator (3), and a voltage stabilizer (411) is arranged on the heat pipe (41).

12. The full-working-condition full-range passive residual heat removal method for the reactor is applied to the full-working-condition full-range passive residual heat removal system for the reactor as claimed in claims 1 to 11, and is characterized by comprising the following steps of:

step S1: establishing a full-range passive residual heat removal system under the full working condition of the reactor;

step S2: according to different working conditions and running states of the reactor (4), the control system controls the starting and stopping of the primary side passive residual heat removal system (1) and the secondary side passive residual heat removal system (2) to finish the removal of the residual heat of the reactor (4).

13. The full-operating-condition full-range passive residual heat removal method for the reactor according to claim 12, wherein in the step S2, based on that the reactor (4) is in normal operation, when the operating condition of the reactor (4) is a hot shutdown operating condition, the control system controls the secondary side passive residual heat removal system (2) to start;

when the working condition of the reactor (4) is a safe shutdown working condition, the control system controls the secondary side passive waste heat discharge system (2) to be started;

when the working condition of the reactor (4) is a transition working condition, the control system controls the primary side passive waste heat discharge system (1) to start;

when the working condition of the reactor (4) is a material changing working condition, water in the water changing tank (11) is directly injected into the reactor (4).

14. The full-operating-condition full-range passive residual heat removal method of the reactor according to claim 13, wherein in the step S2, based on the fact that the reactor (4) is in accident operation, when the operating condition of the reactor (4) is a hot shutdown operating condition, the control system controls the secondary side passive residual heat removal system (2) to start;

when the working condition of the reactor (4) is a safe shutdown working condition, the control system controls the secondary side passive waste heat discharge system (2) to be started;

and when the working condition of the reactor (4) is a transition working condition, the control system controls the primary side passive waste heat removal system (1) to be started.

15. The full-range passive waste heat removal method for the full-operating-condition reactor of claim 14, wherein the hot shutdown condition is that the reactivity of the reactor (4) is less than 0.99 and the temperature of the primary side of the reactor (4) is 300 ℃;

the safe shutdown working condition is that the reactivity of the reactor (4) is less than 0.99, and the temperature of the primary side of the reactor (4) is more than 180 ℃ and less than 300 ℃;

the transition working condition is that the reactivity of the reactor (4) is less than 0.95 and the temperature of the primary side of the reactor (4) is more than 80 ℃ and less than or equal to 180 ℃;

the refueling working condition is that the reactivity of the reactor (4) is less than 0.95, and the temperature of the primary side of the reactor (4) is greater than or equal to 20 ℃ and less than or equal to 80 ℃.

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